Voyager Therapeutics, Inc. 10-K

Voyager Therapeutics, Inc._December 31, 2025 Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 ​ ​ FORM 10-K ​ ​ (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 ​ For the transition period from to Commission File Number: 001-37625 ​ ​ Voyager Therapeutics, Inc. (Exact Name of Registrant as Specified in Its Charter) ​ ​ Delaware 46-3003182 (State or Other Jurisdiction of Incorporation or Organization) (IRS Employer Identification No.) ​ 75 Hayden Avenue , Lexington , Massachusetts 02421 (Address of Principal Executive Offices) (Zip Code) ​ ( 857 ) 259-5340 (Registrant’s Telephone Number, Including Area Code) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $0.001 par value VYGR Nasdaq Global Select Market Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒ Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer ☐ ​ Accelerated filer ☒ Non-accelerated filer ☐ ​ Smaller reporting company ☐ ​ ​ ​ ​ Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements . ☐ Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to § 240.10D-1(b). ☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒ The aggregate market value of common stock held by non-affiliates of the registrant computed by reference to the price of the registrant’s common stock as of June 30, 2025, the last business day of the registrant’s most recently completed second fiscal quarter, was approximately $ 144.2 million (based on the last reported sale price on the Nasdaq Global Select Market as of such date). As of March 2, 2026, there were 59,599,375 shares of the registrant’s common stock, par value $0.001 per share, outstanding. ​ DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive Proxy Statement relating to its 2026 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such Proxy Statement is expected to be filed with the U.S. Securities and Exchange Commission not later than 120 days after the end of the fiscal year to which this report relates. ​ ​ Table of Contents Table of Conte nts ​ ​ ​ Page PART I. ​ ​ ​ ​ Item 1. Business 8 Item 1A. Risk Factors 51 Item 1B. Unresolved Staff Comments 120 Item 1C. ​ Cybersecurity ​ 120 Item 2. Properties 121 Item 3. Legal Proceedings 121 Item 4. Mine Safety Disclosures 121 ​ ​ ​ ​ ​ PART II. ​ Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities 121 Item 6. Reserved 122 Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations 123 Item 7A. Quantitative and Qualitative Disclosures about Market Risk 136 Item 8. Financial Statements and Supplementary Data 137 Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure 137 Item 9A. Controls and Procedures 137 Item 9B. Other Information 141 Item 9C. ​ Disclosure Regarding Foreign Jurisdictions that Prevent Inspections ​ 141 ​ ​ ​ ​ ​ PART III. ​ Item 10. Directors, Executive Officers and Corporate Governance 141 Item 11. Executive Compensation 141 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters 141 Item 13. Certain Relationships and Related Transactions, and Director Independence 141 Item 14. Principal Accountant Fees and Services 141 ​ ​ ​ ​ ​ PART IV. ​ Item 15. Exhibits and Financial Statement Schedules 142 Item 16. ​ Form 10-K Summary ​ 142 ​ ​ ​ ​ ​ Signatures ​ ​ 2 Table of Contents FORWARD-LOOKING STATEMENTS ​ This Annual Report on Form 10-K contains forward-looking statements that involve substantial risks and uncertainties. All statements other than statements of historical facts contained in this Annual Report on Form 10-K, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans, objectives of management and expected market growth, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance, or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. ​ The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “predict,” “project,” “target,” “potential,” “contemplate,” “anticipate,” “goals,” “will,” “would,” “could,” “should,” “continue,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, among other things, statements about: ​ ● our plans to develop and commercialize our proprietary adeno-associated virus, or AAV, gene therapy, antibody, non-viral therapeutic, and small molecule product candidates; ​ ● our ability to continue to develop our proprietary gene therapy platform technologies, including our TRACER TM (Tropism Redirection of AAV by Cell-type-specific Expression of RNA) discovery platform, our non-viral therapeutics platform, including VOY AG ER NEUROSHUTTLE TM , or NeuroShuttle, and our proprietary antibody, small molecule, gene therapy, shuttled or vectorized antibody, and non-viral therapeutic programs; ​ ● our ability to identify and optimize product candidates, proprietary AAV capsids, and non-viral blood-brain-barrier shuttles; ​ ● our strategic collaborations and licensing agreements with, and funding from, our collaboration partners Neurocrine Biosciences, Inc. and Novartis Pharma AG and our licensee Alexion, AstraZeneca Rare Disease (successor-in-interest to former licensee Pfizer Inc.); ​ ● our collaboration with Transition Bio, Inc. to advance small molecules targeting TDP-43 to treat amyotrophic lateral sclerosis and frontotemporal dementia with TDP-43 pathology; ​ ● our ongoing and planned clinical trials, preclinical development efforts, related timelines and studies, including our plans to generate initial data from the Phase 1 multiple ascending dose clinical trial of VY7523 in early Alzheimer’s disease patients in the second half of 2026 and to complete the good laboratory practices toxicology study in the first quarter of 2026 for VY1706 and submit an investigational new drug, or IND, application in the second quarter of 2026 and initiate a clinical trial in the second half of 2026; ​ ● our ability to enter into future collaborations, strategic alliances, or option and license arrangements; ​ ● the timing of and our ability to submit applications and obtain and maintain regulatory approvals for our product candidates, including the ability to submit IND applications for our programs; ​ ● our belief as to potential outcomes of our clinical development activities, and plans and potential outcomes with respect to interactions with regulatory authorities; ​ ● our estimates regarding future revenue, expenses, contingent liabilities, existing cash resources, capital requirements and cash runway; ​ ● our intellectual property position and our ability to obtain, maintain and enforce intellectual property protection for our proprietary assets; 3 Table of Contents ​ ● our estimates regarding the size of the potential markets for our product candidates and our ability to serve those markets; ​ ● our need for and the timing of additional funding and our plans and ability to raise additional capital, including through equity offerings, debt financings, collaborations, strategic alliances, and option and license arrangements; ​ ● our competitive position and the success of competing products that are or might become available for the indications that we are pursuing; ​ ● the impact of government laws and regulations, including in the United States, the European Union, and other important geographies such as Japan; ​ ● our ability to control costs and prioritize our product candidate pipeline and platform development objectives successfully in connection with our strategic initiatives; and ​ ● other risks and uncertainties, including those listed under “ Part I, Item 1A - Risk Factors” and elsewhere in this Annual Report on Form 10-K. ​ These forward-looking statements are only predictions, and we may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements. You should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have based these forward-looking statements largely on our current expectations and projections about future events and trends that we believe may affect our business, financial condition and operating results. We have included important factors in the cautionary statements included in this Annual Report on Form 10-K, particularly in “Part I, Item 1A - Risk Factors” that could cause actual future results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, strategic collaborations, licenses, joint ventures or investments we may make or enter into. ​ You should read this Annual Report on Form 10-K and the documents that we have filed as exhibits to the Annual Report on Form 10-K with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements whether as a result of new information, future events or otherwise, except as required by applicable law. ​ We obtained the statistical and other industry and market data in this Annual Report on Form 10-K and the documents we have filed as exhibits to the Annual Report on Form 10-K from our own internal estimates and research, as well as from industry and general publications and research, surveys, studies and trials conducted by third parties. Some data is also based on our good faith estimates, which are derived from management’s knowledge of the industry and independent sources. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, while we believe the market opportunity information included in this Annual Report on Form 10-K and the documents we have filed as exhibits to the Annual Report on Form 10-K are reliable and are based upon reasonable assumptions, such data involves risks and uncertainties and are subject to change based on various factors, including those discussed under “Risk Factors” and in the documents we have filed as exhibits to the Annual Report on Form 10-K. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Annual Report on Form 10-K, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain, and investors are cautioned not to unduly rely upon these statements. ​ We own various U.S. federal trademark registrations and applications and unregistered trademarks, including our corporate logo. This Annual Report on Form 10-K and the documents filed as exhibits to the Annual Report on Form 4 Table of Contents 10-K contain references to trademarks, service marks and trade names referred to in this Annual Report on Form 10-K and the information incorporated herein, including logos, artwork, and other visual displays, that may appear without the ® or TM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensor to these trademarks, service marks or trade names. We do not intend our use or display of other companies’ trade names, service marks or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies. All trademarks, service marks and trade names included or incorporated by reference into this Annual Report on Form 10-K and the documents filed as exhibits to the Annual Report on Form 10-K are the property of their respective owners. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5 Table of Contents RISK FACTOR SUMMARY ​ Investment in our securities involves risk and uncertainties that you should be aware of when evaluating our business. The following is a summary of what we believe to be the principal risks facing our business, as more fully described under “Part I, Item 1A - Risk Factors” and elsewhere in this Annual Report on Form 10-K. The risks and uncertainties described below are not the only risks and uncertainties we face. Additional risks and uncertainties not presently known to us or that we presently deem less significant may also impair our business operations. ​ ● We have a history of incurring significant losses and anticipate that we will continue to incur losses for the foreseeable future and may never achieve or maintain consistent profitability. ● We will need to raise additional funding, which may not be available on acceptable terms, or at all. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate certain of our product development efforts or other operations. ● Our AAV gene therapy, non-viral therapeutic, and other product candidates are based on proprietary technologies and, in several disease areas, unvalidated treatment approaches, which make it difficult and potentially infeasible to predict the duration and cost of development of, and subsequently obtaining regulatory approval for, our product candidates. ● Regulatory requirements governing gene therapy, non-viral therapeutic, and other products have changed frequently and may continue to change in the future. Such requirements may lengthen the regulatory review process, require us to modify current studies or perform additional studies, or increase our development costs, which in turn may force us to delay, limit, or terminate certain of our programs. ● We are early in our development efforts. VY7523, our anti-tau antibody candidate, is in early-stage clinical trials, and all of our other active product candidates, including VY1706, are currently in preclinical development. We or our collaborators may encounter substantial delays or difficulties in the commencement, enrollment or completion of preclinical studies or clinical trials, or we or our collaborators may fail to demonstrate safety and efficacy sufficient to support further development or to satisfy the applicable regulatory authorities, any of which could prevent us or our collaborators from further developing or commercializing current and future product candidates on a timely basis, if at all. ● Our product candidates may cause undesirable side effects or have other properties that could delay or prevent their further development or regulatory approval, limit their commercial potential or result in significant negative consequences following any potential marketing approval. ● We face significant competition in an environment of rapid technological change and the possibility that our competitors may achieve regulatory approval before us or develop therapies that are more advanced or effective than ours, which may harm our business and financial condition and our ability to successfully market or commercialize our product candidates. ● To date, substantially all of our revenue has been derived from our ongoing collaborations and licensing agreements with Neurocrine, Novartis, and Alexion, and from our prior collaborations with Sanofi Genzyme Corporation, AbbVie Biotechnology Ltd and AbbVie Ireland Unlimited Company. If any ongoing or future collaboration, option and license, or license agreements were to be terminated, our business financial condition, results of operations and prospects could be harmed. ● We may seek to enter into collaborations and out-licensing transactions in the future with other third parties. If we are unable to enter into such collaborations or out-licensing transactions, or if these collaborations or out-licensing transactions are not successful, our business could be adversely affected. ● Our gene therapies, non-viral therapeutics, and other biological modalities are novel, complex and difficult to manufacture. We could experience manufacturing problems that result in delays in the development or commercialization of our product candidates or otherwise harm our business. 6 Table of Contents ● Our future success depends on our ability to retain key members of our management and research and development teams, and to attract, retain and motivate qualified personnel. ● Our gene therapy approach utilizes vectors derived from viruses that are selectively engineered, which may be perceived as unsafe or may result in unforeseen adverse events. Adverse events related to other gene therapy companies and negative public opinion and increased regulatory scrutiny of gene therapy may damage public perception of the safety of our gene therapy product candidates and adversely affect our ability to conduct our business or obtain regulatory approvals for our gene therapy product candidates. ● Our relationships with healthcare providers, physicians and third-party payors will be subject, directly or indirectly, to applicable anti-kickback, fraud and abuse and other healthcare laws and regulations, which, in the event of a violation, could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm and diminished profits and future earnings. ● If we are unable to obtain and maintain patent protection for our products and technology, or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize products and technology similar or identical to ours, and our ability to successfully commercialize our products and technology may be adversely affected, which would have a material adverse impact on our business, results of operations, financial condition and prospects. ● In 2025 and 2026, we reduced the size of our organization in connection with restructurings. We may encounter difficulties in managing our business as a result of these restructurings, or as a result of the attrition that has occurred or may in the future occur due to these restructurings, which could disrupt our operations. In addition, we may not achieve anticipated benefits and savings from these restructurings. ● The price of our common stock may be volatile and fluctuate substantially, which could result in substantial losses for purchasers of our common stock. ​ 7 Table of Contents PART I ITEM 1.      BUSINESS ​ We are a biotechnology company whose mission is to leverage the power of human genetics to modify the course of and ultimately cure neurological diseases. Our pipeline includes programs for Alzheimer’s disease, or AD; Friedreich’s ataxia, or FA; Parkinson’s disease, or PD; and multiple other diseases of the central nervous system, or CNS. Many of our programs are derived from our TRACER™ (Tropism Redirection of AAV by Cell-type-specific Expression of RNA) adeno-associated virus, or AAV, capsid discovery platform, which we have used to generate novel capsids, or TRACER Capsids, and identify associated receptors to potentially enable high brain penetration with genetic medicines following intravenous, or IV, dosing. Some of our programs are wholly-owned, and some are advancing with licensees and collaborators, including Alexion, AstraZeneca Rare Disease, or Alexion; Novartis Pharma AG, or Novartis; Neurocrine Biosciences, Inc., or Neurocrine; and Transition Bio, Inc., or Transition Bio. ​ We are advancing our own proprietary pipeline of drug candidates for neurological diseases, with a focus on AD. Our wholly-owned prioritized pipeline includes two tau targeting programs: VY1706, a tau silencing gene therapy for AD, and VY7523, an anti-tau antibody for AD. VY1706 is a gene therapy that leverages an intravenously delivered TRACER Capsid containing a vectorized small interfering RNA specifically targeting tau mRNA. In a non-human primate, or NHP, study, a single 1.3E13 vector genomes per kilogram, or vg/kg, dose of VY1706 delivered intravenously resulted in reductions in tau mRNA levels of 50% to 73% across the cerebral cortex, including in areas of the brain where tau accumulates during the progression of AD. We expect to complete a good laboratory practices, or GLP, toxicology study in the first quarter of 2026. Having had a Type C communication with the FDA in the first quarter of 2026, we anticipate the submission of an investigational new drug, or IND, application in the second quarter of 2026 and initiation of a clinical trial for the VY1706 program in the second half of 2026. VY7523 is an IV-administered, recombinant, humanized IgG4 monoclonal antibody developed to inhibit the spread of pathological tau, which is closely correlated with disease progression and cognitive decline in AD. The murine version of VY7523 reduced tau spread by approximately 70% in preclinical studies. VY7523 demonstrated an acceptable safety, tolerability, and immunogenicity profile as well as expected pharmacokinetic results in a Phase 1, single ascending dose, or SAD, clinical trial in healthy volunteers. In February 2025, we initiated a Phase 1 multiple ascending dose, or MAD, clinical trial of VY7523 in early AD patients. We expect initial tau positron emission tomography, or PET, imaging data in the second half of 2026. ​ Our proprietary pipeline also includes an early research initiative to develop a non-viral therapeutic that leverages our proprietary Voyager NeuroShuttle TM platform for the treatment of an undisclosed neurological disease. We paused investment in our apolipoprotein E, or APOE, gene therapy program to prioritize other programs. The decision is unrelated to data from the program, which have demonstrated dose-dependent APOE4 protein reduction and APOE2 protein expression in murine studies while maintaining total APOE at physiological levels. ​ In addition to our wholly-owned pipeline, we are advancing three programs with collaboration partners for which we retain options to participate in future development and commercialization. Two of these programs are in collaboration with Neurocrine: a frataxin (FXN) gene therapy program for FA, which we refer to as the FA Program, and a glucosylceramidase beta 1, or GBA1, gene therapy program that will focus on Gaucher and PD, which we refer to as the GBA1 Program. Neurocrine has stated that, pending successful FDA IND clearance, it intends to initiate a clinical trial with NBIB-’223 for FA in the second half of 2026. In preclinical studies, IV-administered NBIB-’223 resulted in protein expression in the brain and heart. Neurocrine has informed us that it continues to progress the GBA1 Program in addition to three gene therapy programs for which we do not have opt-in rights. We maintain an option to co-develop and co-commercialize 40% of the FA Program and 50% of the GBA1 Program for PD in the U.S. ​ Our third opt-in program is our collaboration with Transition Bio to develop selective small molecules for the treatment of amyotrophic lateral sclerosis, or ALS, and frontotemporal dementia with TDP-43 pathology. We have an option for an exclusive license to the worldwide rights to develop and commercialize this program. ​ In addition to the three partnered programs for which we retain opt-in rights, we have entered into multiple additional collaboration and licensing agreements with collaboration partners. ​ 8 Table of Contents We are collaborating with Neurocrine on three gene therapy programs against undisclosed targets. Two of these three programs have development candidates selected and are advancing through preclinical toxicology studies. In addition to the Neurocrine collaborations, we have partnered with Novartis on TRACER Capsid-based gene therapies for spinal muscular atrophy and Huntington’s disease. We have also licensed capsids to Alexion for one undisclosed rare neurological disease target and to Novartis for one undisclosed CNS target. In total, our partnerships have delivered more than $500.0 million in non-dilutive funding to us to date, including upfront fees, development milestone payments, option exercise fees, license fees, and research and development expense reimbursement. Looking forward, we have the potential to earn up to $6.8 billion in milestone payments across the partnered portfolio, including $2.4 billion in potential development milestone payments, as well as royalties. ​ All of the gene therapies in our wholly-owned and collaborative pipeline are delivered intravenously leveraging TRACER capsids. TRACER is a broadly applicable, RNA-based screening platform that enables rapid discovery of AAV capsids with robust penetration of the blood-brain barrier, or BBB, and enhanced CNS tropism in multiple species, including NHPs. We subsequently utilized these BBB-penetrant capsids to identify the receptors by which the capsids enter the BBB. We have identified multiple receptors, including alkaline phosphatase, or ALPL, that are capable of transporting a large biologic molecule, such as a capsid, across the BBB. ​ We have leveraged our knowledge of BBB receptors, discovered using TRACER, to develop a second delivery platform called Voyager NeuroShuttle TM . Voyager NeuroShuttle is a non-viral delivery platform leveraging novel receptor-binding molecules to transport multiple modalities of neurotherapeutics across the blood-brain barrier. The first NeuroShuttle within the platform leverages the ALPL receptor. During the third quarter of 2025, we shared the results of initial murine proof-of-concept studies of ALPL-VYGR-NeuroShuttle demonstrating in the study sustained brain expression over three weeks, compared to less than one week for transferrin receptor, or TfR, shuttles, with no impact on circulating reticulocytes or downstream measurements of anemia. In addition to the initial murine proof-of-concept data provided for the ALPL-VYGR-NeuroShuttle, a proof-of-concept study using anti-amyloid antibodies demonstrated that the ALPL-NeuroShuttle showed similar target engagement to a TfR shuttle. We initiated a discovery program using ALPL-VYGR-NeuroShuttle to target an undisclosed neurological disease. ​ 9 Table of Contents Overview of Our Pipeline ​ Our pipeline of programs is summarized in the table below: ​ ​ Wholly-Owned Programs Tau Silencing Gene Therapy (VY1706) and Anti-Tau Antibody (VY7523) for the Treatment of Alzheimer’s Disease Disease Overview Alzheimer’s disease is a progressive neurodegenerative disease estimated to affect over 7 million older adults in the United States (as of 2025) and up to 416 million older adults globally (as of 2022). The spread of pathological tau as identified via tau PET imaging correlates closely to AD progression as measured by Braak clinical/pathologic staging. Further, recent third-party data have established that both an antibody and an antisense oligonucleotide knockdown approach can decrease accumulation of tau in the brain and potentially impact cognition. Treatment Approach: VY1706 ( Tau Silencing Gene Therapy ) VY1706 is a gene therapy that leverages an intravenously delivered TRACER Capsid containing a vectorized small interfering RNA, specifically targeting tau mRNA. In an NHP study, a single IV 1.3E13 vg/kg dose of VY1706 resulted in reductions in tau mRNA levels of 50% to 73% across the cerebral cortex, including in areas of the brain where tau accumulates during the progression of AD. We expect to complete the GLP toxicology study in the first quarter of 2026. Having had a Type C communication with the FDA in the first quarter of 2026, we anticipate the submission of an IND application in the second quarter of 2026 and initiation of a clinical trial for the VY1706 program in the second half of 2026. Treatment Approach: VY7523 (Anti-Tau Antibody ) ​ VY7523 is an IV-administered, recombinant, humanized IgG4 monoclonal antibody developed to inhibit the spread of pathological tau, which is closely correlated with disease progression and cognitive decline in AD. We believe VY7523 is differentiated from other anti-tau antibodies based on selectivity for pathological tau and the epitope, the part of a foreign protein or antigen that is capable of generating an immune response, it targets, which is located in the C- 10 Table of Contents terminal. Many other anti-tau antibodies are designed to target the N-terminal, mid-domain, or microtubule binding region of the tau protein. ​ In the P301S seeding-propagation tauopathy mouse model, our C-terminal targeting anti-tau antibody blocked the seeding/propagation of filamentous tau and demonstrated substantial (greater than 70%) reduction of induced tau pathology. We conducted a randomized, double-blind, placebo-controlled SAD trial to evaluate the safety, tolerability, and pharmacokinetics of single IV doses of VY7523 in 48 healthy male and female volunteers. VY7523 was generally well tolerated across all six ascending dose cohorts, meeting the primary objective of the trial, with no SAEs, severe adverse events, or infusion reactions reported. The primary endpoints for the trial were incidence of treatment-emergent adverse events and clinically relevant changes from baseline in vital signs, electrocardiograms and clinical laboratory parameters. The secondary endpoints for the trial were various serum pharmacokinetic parameters, cerebrospinal fluid, or CSF, concentrations of VY7523, and incidence, level, and characterization of treatment-emergent anti-drug antibodies. The most frequently reported adverse events were pruritus/itchy skin and scratching, headache, and chest pain. Secondary objectives of the trial were also met. Serum concentrations increased in a dose-proportionate manner, and the CSF-to-serum ratio was 0.3%, consistent with other monoclonal antibodies approved for the treatment of AD. These data were presented at the CTAD 2025 conference. ​ In February 2025, Voyager initiated a MAD trial of VY7523. The MAD study is a randomized, double-blind, placebo-controlled trial to evaluate VY7523 in 52 patients with early AD (mild cognitive impairment due to AD or mild AD). Initial tau PET imaging data are expected in the second half of 2026. ​ Collaboration Programs ​ Friedreich’s Ataxia Program: NBIB-’223 (formerly known as VY-FXN01) (2019 Neurocrine Collaboration) ​ Disease Overview ​ FA is a debilitating neurodegenerative disease resulting in poor coordination of legs and arms, progressive loss of the ability to walk, generalized weakness, loss of sensation, scoliosis, diabetes and cardiomyopathy as well as impaired vision, hearing and speech. The typical age of onset is 10 to 12 years, and life expectancy is severely reduced with patients generally dying of neurological and cardiac complications between the ages of 35 and 45. According to the Friedreich’s Ataxia Research Alliance, there are approximately 5,000 patients living with the disease in the United States. ​ FA patients have mutations of the FXN gene that reduce production of the frataxin protein, resulting in the degeneration of sensory pathways and a variety of debilitating symptoms. FA is an autosomal recessive disorder, meaning that a person must obtain a defective copy of the FXN gene from both parents in order to develop the condition. One healthy copy of the FXN gene, or 50% of normal frataxin protein levels, is sufficient to prevent the disease phenotype. We therefore believe that restoring FXN protein levels to at least 50% of normal levels by AAV gene therapy might lead to a successful therapy. ​ Treatment Approach ​ NBIB-’223 is an intravenously delivered, TRACER-derived capsid containing a functional version of the FXN gene, which is mutated in FA, which we are developing in collaboration with Neurocrine. We initially conducted preclinical studies in NHPs and achieved high FXN expression levels within the target sensory ganglia, or clusters of neurons, along the spinal region following intrathecal injection. More recently, we conducted preclinical studies in NHPs with IV injection and achieved target FXN expression levels within sensory ganglia and the heart. Neurocrine has stated that, pending successful FDA IND clearance, it intends to initiate a clinical trial with NBIB-’223 for FA in the second half of 2026. ​ ​ 11 Table of Contents GBA1 Gene Replacement Program for the Treatment of PD and Gaucher Disease (2023 Neurocrine Collaboration) ​ Disease Overview ​ Mutations in GBA1, the gene encoding the lysosomal glucocerebrosidase enzyme, or Gcase, are responsible for Gaucher disease and are also the most common genetic risk factor for synucleinopathies such as PD. Gaucher disease affects approximately 6,000 patients in the U.S., and there are currently no treatments available for neurological involvement in Type 2 and Type 3 Gaucher disease. PD is among the most common neurodegenerative diseases, affecting about one million patients in the United States and more than 10.0 million patients worldwide. Up to 10% of PD patients have a GBA1 mutation, and these mutations increase the risk of PD by approximately 20-fold. ​ Treatment Approach We and Neurocrine are developing a gene therapy leveraging a BBB-penetrant, CNS-tropic TRACER Capsid to treat diseases linked to GBA1 mutations via a gene replacement approach. We have presented data from mouse studies with respect to three potential development candidates. Each demonstrated significant improvement in several efficacy biomarkers, and additional data from an NHP study demonstrated that the administration of a reporter transgene via a single, IV dose using two novel BBB-penetrant AAV capsids substantially improved biodistribution and gene expression compared to conventional AAV9 in the putamen and substantia nigra, two areas of the brain that are affected in PD. This program is progressing in preclinical development. ​ HD Program (2023 Novartis Collaboration Agreement) Disease Overview ​ Huntington’s disease, or HD, is a fatal, inherited neurodegenerative disease that results in the progressive decline of motor and cognitive functions and a range of behavioral and psychiatric disturbances. HD is caused by mutations in the huntingtin, or HTT, gene. HD is an autosomal dominant disorder, which means that an individual is at risk of inheriting the disease if only one parent is affected. While the exact function of the HTT gene in healthy individuals is unknown, it is essential for normal development before birth. Mutations in the HTT gene ultimately lead to the production of abnormal intracellular huntingtin protein aggregates and expansions in the gene in neurons that may cause neuronal cell death. ​ Program Status On December 28, 2023, we entered into a license and collaboration agreement with Novartis, or the 2023 Novartis Collaboration Agreement. Under the 2023 Novartis Collaboration Agreement, we and Novartis have agreed to collaborate to develop AAV gene therapy products and product candidates intended for the treatment of HD, which we refer to as the Novartis HD Program. The Novartis HD Program is currently in preclinical development. From and after the first IND application filing for the Novartis HD Program, we and Novartis have agreed that Novartis will assume sole responsibility for the development and commercialization of gene therapy products and product candidates under the Novartis HD Program, including all further preclinical and clinical development and any commercialization of the Novartis HD Program products and product candidates. ​ Collaboration Programs and Licensing Agreements ​ 2023 Novartis Collaboration Agreement ​ On December 28, 2023, or the 2023 Novartis Collaboration Agreement Effective Date, we entered into the 2023 Novartis Collaboration Agreement, with Novartis to (a) provide rights to Novartis with respect to certain TRACER Capsids for use in the research, development, and commercialization by Novartis of AAV gene therapy products and product candidates, comprising such TRACER Capsids and payloads intended for the treatment of spinal muscular atrophy, or the Novartis SMA Program, and (b) collaborate to develop AAV gene therapy products and product 12 Table of Contents candidates under the Novartis HD Program, in each case, leveraging TRACER Capsids and other intellectual property controlled by us. ​ Novartis SMA Program and Novartis HD Program Licenses ​ Under the terms of the 2023 Novartis Collaboration Agreement, we granted to Novartis and its affiliates: ​ ● a non-exclusive, non-transferable, non-sublicensable (except in limited circumstances for contractors), worldwide, royalty-free right and license under any patents or know-how controlled by us and related to the TRACER Capsids to evaluate the same for use in the development of a product or product candidate under the Novartis SMA Program, or a Novartis SMA Program Product, comprising such a TRACER Capsid and a payload selected by Novartis during the period beginning on the 2023 Novartis Collaboration Agreement Effective Date and ending on the third anniversary of the 2023 Novartis Collaboration Agreement Effective Date; ​ ● an exclusive (even as to us), sublicensable, non-transferable, worldwide, royalty-bearing right and license under any patents or know-how controlled by us and relating to the selected TRACER Capsids to exploit the same as incorporated into a Novartis SMA Program Product for all human and veterinary diagnostic, prophylactic and therapeutic uses during the 2023 Novartis Collaboration Term (as defined below); and ​ ● an exclusive (even as to us), sublicensable, non-transferable, worldwide, royalty-bearing right and license under any patents and know-how controlled by us and relating to the development of a product or product candidate under the Novartis HD Program, or a Novartis HD Program Product to exploit the same for all human and veterinary diagnostic, prophylactic and therapeutic uses during the 2023 Novartis Collaboration Term. Governance ​ We and Novartis have agreed to manage the Novartis HD Program through a Joint Steering Committee until dissolved after the first IND application filing for a Novartis HD Program Product. We and Novartis have further agreed that day-to-day activities of both the Novartis SMA Program and the Novartis HD Program shall be managed through designees from each of us and Novartis, acting as alliance managers. ​ Development, Regulatory Approval, Commercialization and Diligence. ​ Under the 2023 Novartis Collaboration Agreement, Novartis is solely responsible for, and has sole decision-making authority with respect to, at its own expense, the exploitation of a Novartis SMA Program Product. ​ With respect to the Novartis HD Program, the parties have agreed to conduct research and pre-clinical development of Novartis HD Program Products pursuant to a research plan, with Novartis reimbursing us for our activities thereunder in accordance with the agreed-to budget. From and after the first IND application filing for the Novartis HD Program, the parties have agreed that Novartis will assume sole responsibility for the development and commercialization of Novartis HD Program Products, including all further preclinical and clinical development and any commercialization of the Novartis HD Program products and product candidates. ​ With respect to each of the Novartis SMA Program Products and Novartis HD Program Products, Novartis is obligated to use commercially reasonable efforts to develop and obtain regulatory approval for at least one of each such product in the United States and in certain other international markets specified in the 2023 Novartis Collaboration Agreement. ​ Intellectual Property ​ Under the terms of the 2023 Novartis Collaboration Agreement, each party owns the entire right, title, and interest in and to all patents or know-how controlled by such party and existing as of or before the 2023 Novartis Collaboration Agreement Effective Date, or invented, authored, discovered, developed, created or acquired solely by or 13 Table of Contents on behalf of such party after the 2023 Novartis Collaboration Effective Date outside of its activities under the 2023 Novartis Collaboration Agreement. ​ We and Novartis have further agreed that all know-how created by either or both parties in the performance of the activities as undertaken pursuant to the performance of the Novartis HD Program plan or in the course of development, manufacture and commercialization of Novartis HD Program Products and all patent rights covering such know-how, or collectively, the 2023 Novartis Arising IP, is to be owned as follows: (a) we solely own all 2023 Novartis Arising IP comprised of know-how or other intellectual property rights related to any TRACER Capsid, including the use or manufacture of any TRACER Capsid, and that is created jointly by our representatives and representatives of Novartis or created solely by representatives of Novartis through the use of our confidential information; and (b) with respect to all other 2023 Novartis Arising IP, (i) we solely own all such 2023 Novartis Arising IP created solely by our representatives, (ii) Novartis solely owns all such 2023 Novartis Arising IP created solely by Novartis representatives; and (iii) the parties jointly own all such 2023 Novartis Arising IP created jointly by representatives of both Novartis and us. ​ Exclusivity ​ Subject to certain limitations and exceptions, we have agreed during the 2023 Novartis Collaboration Term not to (a) conduct any wholly-owned program or program on behalf of a third party that is directed to the development or commercialization of any capsids for use in any therapeutic product containing a capsid in combination with a payload designed to have therapeutic effect on the gene agreed between the parties as the target of the Novartis SMA Program when packaged into a capsid and delivered to the appropriate cells; (b) develop or commercialize any competing Novartis HD Program Product intended to have a therapeutic effect on genes agreed between the parties as the targets of the Novartis HD Program; or (c) grant any third party any right, license, option, covenant not to assert or similar right, under any patents or know-how controlled by us or our affiliates (excluding an acquiring entity) as of the 2023 Novartis Collaboration Agreement Effective Date or during the 2023 Novartis Collaboration Term, that would enable a third party to do any of the foregoing. ​ Termination ​ Unless earlier terminated, with respect to any licensed product(s) under the 2023 Novartis Collaboration Agreement, on a country-by-country basis, the 2023 Novartis Collaboration Agreement expires upon the expiration of the last-to-expire royalty term with respect to such licensed product in such country in the territory, or the 2023 Novartis Collaboration Term. Subject to a cure period, either party may terminate the 2023 Novartis Collaboration Agreement, in whole or in part, subject to specified conditions, in the event of the other party’s uncured material breach. Novartis may also terminate the 2023 Novartis Collaboration Agreement, in whole or in part, subject to specified conditions, for our insolvency, for the occurrence of a violation of global trade control laws, or for our non-compliance with certain anti-bribery or anti-corruption covenants. Novartis may terminate the 2023 Novartis Collaboration Agreement, in whole or in part, for any or no reason upon ninety days’ written notice to us. In the event that Novartis has the right to terminate the 2023 Novartis Collaboration Agreement as a result of an uncured material breach by us that materially impairs the ability of Novartis to exploit one or more licensed products, Novartis may, in lieu of such termination, elect for the 2023 Novartis Collaboration Agreement to remain in full force and effect, and all milestone payments and royalties that would have otherwise been payable by Novartis under such licenses had the 2023 Novartis Collaboration Agreement not been breached would be substantially reduced. ​ Financial Terms ​ Under the 2023 Novartis Collaboration Agreement, Novartis paid us an upfront payment of $80.0 million. We are eligible to receive specified development, regulatory, and commercialization milestone payments of up to an aggregate of $200.0 million for the Novartis SMA Program and up to an aggregate of $225.0 million for the Novartis HD Program, in each case for the first corresponding product to achieve the corresponding milestone. We are also eligible to receive (a) specified sales milestone payments of up to an aggregate of $400.0 million for the Novartis SMA Program and up to an aggregate of $375.0 million for the Novartis HD Program and (b) tiered, escalating royalties in the high single-digit to low double-digit percentages of annual net sales of the Novartis SMA Program Products and the 14 Table of Contents Novartis HD Program Products. The royalties are subject to potential customary reductions, including patent claim expiration, payments for certain third-party licenses, and biosimilar market penetration, subject to specified limits. 2022 Novartis Option and License Agreement Summary of Agreement ​ On March 4, 2022, or the 2022 Novartis Option and License Effective Date, we entered into an option and license agreement with Novartis, or the 2022 Novartis Option and License Agreement. Pursuant to the 2022 Novartis Option and License Agreement, we granted Novartis options, or the Novartis License Options, to license TRACER Capsids, or the Novartis Licensed Capsids, for exclusive use in programs targeting three specified genes, or the Initial Novartis Targets, to develop and commercialize AAV gene therapy candidates comprised of Novartis Licensed Capsids and payloads directed to such targets, or the Novartis Initial Licensed Products. Effective as of March 1, 2023, Novartis exercised its Novartis License Options to license TRACER Capsids for use in gene therapy programs against two undisclosed programs targeting specified genes, or the Initial Novartis Targets. Upon Novartis’ exercise of the two Novartis License Options for Initial Novartis Targets, we granted Novartis a target-exclusive, worldwide license, with the right to sublicense, under certain of our intellectual property, the rights to develop and commercialize the applicable Novartis Licensed Capsid as incorporated into Novartis Initial Licensed Products. We also agreed to provide certain additional know-how to enable Novartis to exploit the Novartis Licensed Capsid and a payload directed to the applicable Initial Novartis Target for use in an Initial Novartis Licensed Product. Novartis elected not to license a capsid for one Initial Novartis Target prior to the expiration of the applicable Novartis License Option. As a result, the non-exclusive research license that we granted to Novartis in connection with this third Initial Novartis Target terminated, and all capsid rights with respect to that Initial Novartis Target returned to us. ​ On September 3, 2024, we entered into an amendment, or the Novartis Amendment, to the 2022 Novartis Option and License Agreement. Pursuant to the Novartis Amendment, we agreed to amend the 2022 Novartis Option and License Agreement to incorporate the grant to Novartis of a direct license, or the Novartis Direct License, to a TRACER Capsid, or the Novartis Direct Licensed Capsid, for exclusive use with a certain gene, or the Novartis Direct License Target, to develop and commercialize the Novartis Direct Licensed Capsid as incorporated into AAV gene therapy candidates comprised of the Novartis Direct Licensed Capsid and a payload directed to the Novartis Direct License Target, or Novartis Direct Licensed Products. We refer to (a) the two Initial Novartis Targets for which Novartis has exercised its Novartis License Options and the Novartis Direct License Target collectively as Novartis Licensed Targets, and (b) the Novartis Initial Licensed Products and Novartis Direct Licensed Products collectively as Novartis Licensed Products. As a result of the Novartis Amendment, the Novartis Direct License Target was deemed a Licensed Target under the 2022 Novartis Option and License Agreement, as such term is defined therein, and the Novartis Direct License became subject to all other terms and conditions applicable to other licenses granted to Novartis under the 2022 Novartis Option and License Agreement. In connection with the Novartis Amendment, the parties acknowledged that Novartis’ prior rights to exercise options for any initial targets and additional targets as described in the 2022 Novartis Option and License Agreement, other than those that had previously been exercised, had expired as of the effective date of the Novartis Amendment. ​ Under the terms of the 2022 Novartis Option and License Agreement, Novartis has the right to terminate the agreement, in whole or in part, for any or no reason upon ninety days’ written notice to us. In October 2025, Novartis notified us of its partial termination of the 2022 Novartis Option and License Agreement with respect to one Initial Novartis Target and the Novartis Direct License Target, in each case effective February 1, 2026, or the Effective Partial Termination Date. ​ Following the termination of the two programs, the licenses we granted to Novartis regarding the applicable Initial Novartis Target and the Novartis Direct License Target expired, and all intellectual property rights that we licensed to Novartis with respect to such programs reverted to us in accordance with the 2022 Novartis Option and License Agreement. As of the Effective Partial Termination Date, we are no longer eligible to receive the milestone payments or royalties associated these programs. The 2022 Novartis Option and License Agreement remains in full force 15 Table of Contents and effect for, and we remain eligible to receive milestone payments in the amount of up to $300.0 million as well as mid- to high-single-digit royalties in connection with, the remaining program under the agreement. ​ Governance ​ Subject to our disclosure obligations described above, we and Novartis have agreed to conduct our respective research and evaluation activities independently, with communications being managed by two alliance managers comprised of a designee from each of the parties. ​ Development, Regulatory Approval, and Commercialization ​ Under the 2022 Novartis Option and License Agreement, Novartis is solely responsible for, and has sole decision-making authority with respect to, development and commercialization of the Novartis Licensed Products. Novartis is required to use commercially reasonable efforts to develop and obtain regulatory approval for at least one Novartis Licensed Product for each Novartis Licensed Target in (a) the United States and (b) at least three of the following countries: the United Kingdom, France, Germany, Italy, Spain and Japan, each of which we refer to as a Novartis Major Market Country, subject to certain limitations. Novartis is also required to use commercially reasonable efforts to commercialize each Novartis Licensed Product in the United States and at least three Novartis Major Market Countries where Novartis or its designated affiliates or sublicensees has received regulatory approval for such Novartis Licensed Product, subject to certain limitations. ​ The Novartis Research Term under the 2022 Novartis Option and License Agreement expired in March 2025. ​ Financial Terms ​ Under the terms of the 2022 Novartis Option and License Agreement, Novartis paid us an upfront payment of $54.0 million. Effective as of March 1, 2023, Novartis exercised its Novartis License Options to license TRACER Capsids for use in gene therapy programs against two undisclosed Initial Novartis Targets. With Novartis’ option exercise on two Initial Novartis Targets, we received a $25.0 million option exercise payment in April 2023. Novartis paid us a one-time fee of $15.0 million in consideration for the rights granted under the Novartis Amendment, which we received in October 2024. Following the partial termination of the 2022 Novartis Option and License Agreement by Novartis in October 2025, the 2022 Novartis Option and License Agreement remains active with respect to one gene therapy program for one Initial Novartis Target. We are eligible to receive specified development, regulatory, and commercialization milestone payments of up to an aggregate of $125.0 million for the first Novartis Initial Licensed Product for the remaining Initial Novartis Target for which a Novartis License Option has been exercised to achieve the corresponding milestone. We are eligible to receive (a) specified sales milestone payments of up to an aggregate of $175.0 million per Novartis Licensed Product directed to the remaining Initial Novartis Target and (b) tiered, escalating royalties in the mid- to high-single-digit percentages based on annual net sales of each Novartis Licensed Product directed to the remaining Initial Novartis Target. The remaining Initial Novartis Target is distinct from targets in our wholly-owned and partnered pipeline. ​ Intellectual Property ​ Under the terms of the 2022 Novartis Option and License Agreement, each party owns the entire right, title, and interest in and to all patents or know-how controlled by such party and existing as of or before the 2022 Novartis Option and License Effective Date, or invented, developed, created, generated or acquired solely by or on behalf of such party after the 2022 Novartis Option and License Effective Date. Subject to certain specified exceptions, any patents and know-how that are invented or otherwise developed jointly by or on behalf of the parties during the term of the 2022 Novartis Option and License Agreement and in the course of the parties’ activities under the 2022 Novartis Option and License Agreement will follow inventorship under U.S. patent law. ​ 16 Table of Contents Exclusivity ​ Subject to certain limitations and exceptions, we agreed (a) during the Novartis Research Term, which expired in March 2025, not to conduct any internal program or program on behalf of a third party that is directed to the development or commercialization of any of our capsids, or grant any third party or affiliate any right or license under our rights in such capsids, to exploit any therapeutic product containing a capsid in combination with a payload designed to have therapeutic effect on any of the Novartis Licensed Targets; and (b) not to grant any third party or affiliate any right or license under our patents to exploit the Novartis Licensed Capsid for the Novartis Licensed Target. ​ Termination ​ Unless earlier terminated, the 2022 Novartis Option and License Agreement expires on the expiration of the last-to-expire royalty term with respect to all Novartis Licensed Products in all countries. Subject to a cure period, either party may terminate the 2022 Novartis Option and License Agreement, in whole or in part, subject to specified conditions, in the event of the other party’s uncured material breach. Novartis may also terminate the 2022 Novartis Option and License Agreement, in whole or in part, subject to specified conditions, for our insolvency, the occurrence of a violation of global trade control laws, or for our non-compliance with certain anti-bribery or anti-corruption covenants. Novartis may terminate the 2022 Novartis Option and License Agreement, in whole or in part, for any or no reason upon ninety days’ written notice to us. In October 2025, Novartis notified us of its partial termination of the 2022 Novartis Option and License Agreement, for Novartis’ convenience and in accordance with the terms of the 2022 Novartis Option and License Agreement, with respect to one Initial Novartis Target and the Novartis Direct License Target as of the Effective Partial Termination Date. ​ Upon certain terminations for cause by Novartis, the licenses granted by us to Novartis under the 2022 Novartis Option and License Agreement shall become irrevocable and perpetual, and all milestone payments and royalties that would have otherwise been payable by Novartis under such licenses had the 2022 Novartis Option and License Agreement remained in effect would be substantially reduced. ​ 2023 Neurocrine Collaboration Agreement ​ Summary of Agreement ​ On January 8, 2023, we entered into the 2023 Neurocrine Collaboration Agreement for the research, development, manufacture and commercialization of the GBA1 Program, and three new programs focused on the research, development, manufacture and commercialization of gene therapies designed to address CNS diseases or conditions associated with rare genetic targets, or the 2023 Discovery Programs and, collectively with the GBA1 Program, the 2023 Neurocrine Programs. ​ Collaboration and License ​ Under the 2023 Neurocrine Collaboration Agreement, we and Neurocrine have agreed to collaborate on the conduct of the 2023 Neurocrine Programs. The 2023 Neurocrine Collaboration Agreement became effective upon the expiration of all applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, which occurred on February 21, 2023, or the Neurocrine Effective Date. Under the terms of the 2023 Neurocrine Collaboration Agreement, subject to the rights retained by us thereunder, we granted to Neurocrine, as of the Neurocrine Effective Date, an exclusive, royalty-bearing, sublicensable, worldwide license, under certain of our intellectual property rights, to research, develop, manufacture and commercialize gene therapy products, or the 2023 Collaboration Products, arising under the 2023 Neurocrine Programs. Pursuant to mutually-agreed development plans, during the period beginning on the Neurocrine Effective Date and ending on the third anniversary of the Neurocrine Effective Date, which period may be extended upon mutual written agreement of us and Neurocrine, or the 2023 Discovery Period, and as overseen by the Joint Steering Committee that oversees our ongoing collaboration with Neurocrine, we are responsible for identifying capsids meeting target criteria, producing development candidates, and conducting other non-clinical activities regarding the 2023 17 Table of Contents Collaboration Products. The 2023 Discovery Period expired on February 21, 2026. With the exception of one preclinical study where we agreed to share costs, Neurocrine has agreed to be responsible for all costs we incur in conducting preclinical development activities for each 2023 Neurocrine Program, in accordance with JSC-agreed upon workplans and budgets. If we breach our development responsibilities or, in certain circumstances, upon a change of control, Neurocrine has the right, but not the obligation, to assume the conduct of our activities under such 2023 Neurocrine Program. We have been granted the option, or a 2023 Co-Co Option, to co-develop and co-commercialize 2023 Collaboration Products in the GBA1 Program in the United States upon the occurrence of a specified event, or a 2023 Co-Co Trigger Event. Should we elect to exercise our 2023 Co-Co Option, we and Neurocrine agree to enter into a cost- and profit-sharing arrangement, or a 2023 Co-Co Agreement, whereby we and Neurocrine agree to jointly develop and commercialize 2023 Collaboration Products in the GBA1 Program, or 2023 Co-Co Products, in the United States and share equally in the GBA1 Program’s costs, profits and losses in the United States, with each party entitled to or responsible for 50% of profits and losses with respect to each 2023 Co-Co Product in the United States, subject to specified exceptions. The parties have agreed that the 2023 Co-Co Agreement will provide us the right to terminate the 2023 Co-Co Agreement for any reason upon prior written notice to Neurocrine and provide Neurocrine the right to terminate or amend the 2023 Co-Co Agreement upon a change of control under certain circumstances. In the event we exercise our 2023 Co-Co Option, the parties have also agreed that Neurocrine is entitled to receive (in addition to its 50% share of profits) 50% of our share of profits until our obligation to repay 50% of all development costs incurred by Neurocrine in connection with the GBA1 Program prior to such exercise have been paid off. The 2023 Co-Co Trigger Event is the date on which we receive topline data from the first clinical trial for a product candidate being developed for PD pursuant to the GBA1 Program or if none, then another indication under the GBA1 Program. ​ Governance ​ Our research and development activities under the 2023 Neurocrine Collaboration Agreement are to be conducted pursuant to plans agreed to by the parties, on a 2023 Neurocrine Program-by-2023 Neurocrine Program basis, and overseen by the JSC, which is composed of an equal number of representatives from each of us and Neurocrine. The JSC may delegate matters within its authority to subcommittees of the JSC. In addition, the 2023 Collaboration Agreement establishes working groups to handle specified matters on a subject matter-by-subject matter basis. If a working group or subcommittee cannot agree on a matter within its purview within a specified time, such matter is to be referred sequentially to the JSC and then the executive officers of the parties. If the executive officers are not able to resolve the matter, then (a) with respect to the GBA1 Program, subject to specified exceptions, (i) Neurocrine has the right to resolve such matter prior to our exercise of our 2023 Co-Co Option for the GBA1 Program or in the event we elect not to exercise our 2023 Co-Co Option, and (ii) following the exercise by us of our 2023 Co-Co Option for the GBA1 Program, depending on the subject of such matter, either Neurocrine, in certain instances, or the parties jointly or the JSC, in other instances, would have the right to resolve such matter, and (b) with respect to the 2023 Discovery Programs, subject to specified exceptions, Neurocrine has the right to decide any unresolved matters relating to a 2023 Discovery Program that are within the JSC’s authority. ​ Candidate Selection ​ Either party may notify the JSC of any gene therapy product candidate that includes a Voyager capsid and a payload that is being developed under a 2023 Neurocrine Program, or a Collaboration Candidate, that it desires to nominate as a development candidate. In such event, the JSC shall determine whether such nominated Collaboration Candidate meets certain development criteria. There will be a maximum of four potential development candidates for which development is being performed under any 2023 Neurocrine Program at any given time during the 2023 Discovery Period, which expired in February 2026. If a Collaboration Candidate fails to meet criteria established by the JSC and is removed from consideration to become a development candidate or is named a development candidate, then a new Collaboration Candidate may be nominated to be a potential development candidate to replace the Collaboration Candidate that has failed or succeeded such that not more than four potential development candidates per program are under consideration at any one time during the 2023 Discovery Period. ​ ​ 18 Table of Contents Manufacturing ​ The parties have agreed that the applicable development plans shall specify the allocation between us and Neurocrine of responsibilities for the manufacturing of Collaboration Candidates associated with the applicable 2023 Neurocrine Program during the 2023 Discovery Period. In accordance with the 2023 Collaboration Agreement, the parties have also agreed that, if we conduct any portion of the manufacturing of a Collaboration Candidate, the applicable development plan shall include an obligation for us to assist with the technology transfer of such manufacturing responsibilities to Neurocrine or a third-party contract manufacturing organization, as reasonably requested by Neurocrine, on terms to be mutually-agreed by us and Neurocrine. Following the end of the 2023 Discovery Period, which expired in February 2026, Neurocrine shall be responsible for the manufacturing of all Collaboration Candidates and products. ​ Financial Terms ​ Under the terms of the 2023 Neurocrine Collaboration Agreement, Neurocrine paid us an upfront payment of approximately $136.0 million and approximately $39.0 million as consideration for an equity purchase of 4,395,588 shares of our common stock in February 2023. The 2023 Collaboration Agreement provides for aggregate development milestone payments from Neurocrine to us for 2023 Collaboration Products under (a) the GBA1 Program of up to $985.0 million; and (b) each of the three 2023 Discovery Programs of up to $175.0 million for each 2023 Discovery Program. We may be entitled to receive aggregate commercial milestone payments for up to two 2023 Collaboration Products under the GBA1 Program of up to $950.0 million per 2023 Collaboration Product and for one 2023 Collaboration Product under each 2023 Discovery Program of up to $275.0 million per 2023 Discovery Program. We agreed to forfeit certain milestones and royalties on net sales in the United States if we exercise the 2023 Co-Co Option. The JSC’s selection of the lead development candidate for the GBA1 Program in April 2024 triggered a $3.0 million milestone payment, which we received in May 2024. Additionally, the JSC’s selection of the development candidate for a 2023 Discovery Program in September 2024 triggered a $3.0 million milestone payment, which we received in October 2024. An additional development candidate for a 2023 Discovery Program was selected by the JSC in October 2025, triggering another $3.0 million milestone payment, which we received in November 2025. Neurocrine has also agreed to pay us tiered royalties, based on future net sales of the 2023 Collaboration Products. Such royalty percentages, for net sales in and outside the United States, range from (a) for the GBA1 Program, the low double-digits to twenty and the high single-digits to mid-teens, respectively, and (b) for each 2023 Discovery Program, high single-digits to mid-teens and mid-single digits to low double-digits, respectively. On a country-by-country and 2023 Neurocrine Program-by-2023 Neurocrine Program basis, the parties have agreed royalty payments would commence on the first commercial sale of a 2023 Collaboration Product in such country and terminate upon the latest of (x) the expiration, invalidation or the abandonment of the last patent covering the composition of the 2023 Collaboration Product or its approved method of use in such country, (y) ten years from the first commercial sale of the 2023 Collaboration Product in such country and (z) the expiration of regulatory exclusivity in such country, or the 2023 Royalty Term. Royalty payments may be reduced by up to 50% in specified circumstances, including expiration of patent rights related to a 2023 Collaboration Product, approval of biosimilar products in a given country, or required payment of licensing fees to third parties related to the development and commercialization of any 2023 Collaboration Product. Additionally, the licenses granted to Neurocrine shall automatically convert to a fully-paid, perpetual, irrevocable royalty-free license on a country-by-country and 2023 Collaboration Product-by-2023 Collaboration Product basis upon the expiration of the 2023 Royalty Term applicable to the 2023 Collaboration Product in such country. ​ Intellectual Property ​ Under the terms of the 2023 Neurocrine Collaboration Agreement, each party owns all right, title and interest in and to all patent rights or know-how controlled by such party and existing as of or before the Neurocrine Effective Date or created or acquired solely by or on behalf of such party (including through its or its affiliate’s representatives) after the Neurocrine Effective Date outside of its activities under the 2023 Neurocrine Collaboration Agreement. The parties have further agreed that all know-how created by either or both parties in the performance of the activities as undertaken pursuant to a development plan during the 2023 Discovery Period or in the course of development, manufacture and commercialization of Collaboration Candidates or products and all patent rights covering such know-how, or collectively 19 Table of Contents the 2023 Neurocrine Arising IP, is to be owned as follows: (a) we solely own all 2023 Neurocrine Arising IP created jointly by representatives of us and Neurocrine that constitutes capsid know-how and capsid patent rights, and 2023 Neurocrine Arising IP created solely by representatives of Neurocrine through the use of our confidential information, including unpublished sequence information for our capsids; and (b) with respect to all other 2023 Neurocrine Arising IP, (i) we solely own all such 2023 Neurocrine Arising IP created solely by our representatives, (ii) Neurocrine solely owns all such 2023 Neurocrine Arising IP created solely by Neurocrine representatives; and (iii) the parties jointly own all such 2023 Neurocrine Arising IP created jointly by representatives of both Neurocrine and us. 2023 Neurocrine Arising IP owned by us is included in the license granted from us to Neurocrine described above. ​ Exclusivity ​ During the term of the 2023 Neurocrine Collaboration Agreement, neither party nor any of its respective affiliates is permitted to directly or indirectly develop, manufacture or commercialize any other gene therapy product directed to a target under any 2023 Neurocrine Program, or grant any affiliate or third party a license or sublicense to enable any third party to do so, subject to specified exceptions, including the parties’ conduct of certain basic research, provided that Neurocrine or its affiliates may develop competitive products that do not contain an adeno-associated virus as the viral vector. ​ Termination ​ Unless earlier terminated, the 2023 Neurocrine Collaboration Agreement expires on the later of (a) the expiration of the last-to-expire 2023 Royalty Term with respect to all 2023 Collaboration Products worldwide or (b) the expiration or termination of any 2023 Co-Co Agreement. Neurocrine may terminate the 2023 Neurocrine Collaboration Agreement in its entirety or on a 2023 Neurocrine Program-by-2023 Neurocrine Program and/or country-by-country basis by providing at least (x) 180-day advance notice if such notice is provided prior to the first commercial sale of any 2023 Collaboration Product to which the termination applies or (y) one-year advance notice if such notice is provided after the first commercial sale of any product to which the termination applies. Neurocrine may terminate the 2023 Neurocrine Collaboration Agreement with respect to a given 2023 Collaboration Product by providing written notice of termination to us within thirty days after complete readout of any clinical trial if the results of such clinical trial fail to meet the pre-specified primary endpoint(s) set forth in the applicable protocol or if there is a safety finding during the clinical trial relating to such 2023 Collaboration Product that either (i) is substantially irreversible or not monitorable in patients or (ii) results in Neurocrine’s decision to designate such 2023 Collaboration Product as a terminated product under the 2023 Collaboration Agreement. We may terminate the 2023 Neurocrine Collaboration Agreement with respect to a particular patent right of ours, if Neurocrine challenges the validity or enforceability of such patent right. Subject to a cure period, either party may terminate the 2023 Neurocrine Collaboration Agreement in the event of a material breach in whole or in part, subject to specified conditions. ​ 2019 Neurocrine Collaboration Agreement ​ In January 2019, we entered into the 2019 Neurocrine Collaboration Agreement for the research, development and commercialization of certain of our AAV gene therapy products. Under the 2019 Neurocrine Collaboration Agreement, we agreed to collaborate on the conduct of four collaboration programs, which we refer to collectively as the 2019 Neurocrine Programs: the NBIb-1817 (VY-AADC) program for the treatment of PD, or the VY-AADC Program; the FA Program; and other undisclosed programs, or the 2019 Discovery Programs. On February 2, 2021, Neurocrine notified us that it had elected to terminate the 2019 Neurocrine Collaboration Agreement solely with regards to the VY-AADC Program, effective as of August 2, 2021, which we refer to as the Neurocrine VY-AADC Program Termination Effective Date. As a result of the termination, as of the Neurocrine VY-AADC Program Termination Effective Date, the license granted by us to Neurocrine thereunder regarding the VY-AADC Program expired and we regained worldwide intellectual property rights regarding the VY-AADC Program. ​ On April 30, 2025, as a result of Neurocrine no longer prioritizing the two 2019 Discovery Programs, the JSC mutually agreed to discontinue the activities associated with such programs, and to return the rights to the undisclosed 20 Table of Contents targets to us. As a result of the discontinuation, the licenses granted by us to Neurocrine thereunder regarding the 2019 Discovery Programs terminated and we regained worldwide intellectual property rights regarding such programs. The 2019 Neurocrine Collaboration Agreement remains in full force and effect for the FA Program. ​ Collaboration and Licenses Under the terms of the 2019 Neurocrine Collaboration Agreement, subject to the rights retained by us thereunder, we agreed to collaborate with Neurocrine on, and to grant, exclusive, royalty-bearing, non-transferable, sublicensable licenses to certain of our intellectual property rights, for all human and veterinary diagnostic, prophylactic, and therapeutic uses, for the research, development, and commercialization of gene therapy products, which we refer to as the 2019 Collaboration Products, under (a) the VY-AADC Program on a worldwide basis; (b) the FA Program, in the United States and, all countries in the world in which the 2019 Neurocrine Collaboration Agreement remains in effect with respect to the FA Program; and (c) each of the 2019 Discovery Programs, on a worldwide basis. Licenses related to the VY-AADC Program terminated in August 2021. Licenses related to the two 2019 Discovery Programs terminated in April 2025. ​ In connection with the June 2019 termination of the collaboration agreement with Sanofi Genzyme Corporation, we gained ex-U.S. rights to the FA program. We subsequently transferred the ex-U.S. rights to the FA Program to Neurocrine pursuant to the 2019 Neurocrine Collaboration Agreement. To facilitate our transfer of the ex-U.S. rights to the FA Program to Neurocrine, we and Neurocrine amended the 2019 Neurocrine Collaboration Agreement, and we received a $5.0 million payment from Neurocrine. ​ Pursuant to development plans to be agreed by the parties, which are overseen by the JSC, we have operational responsibility, subject to certain exceptions, for the conduct of each 2019 Neurocrine Program prior to the occurrence of a specified event for each 2019 Neurocrine Program, or a 2019 Transition Event, and are required to use commercially reasonable efforts to develop the 2019 Collaboration Products. Neurocrine has agreed to be responsible for all costs incurred by us in conducting these activities for each 2019 Neurocrine Program, in accordance with an agreed budget. If we breach our development responsibilities or in certain circumstances upon a change in control of us, Neurocrine has the right but not the obligation to assume the activities under such 2019 Neurocrine Program. ​ Upon the occurrence of a 2019 Transition Event for each 2019 Neurocrine Program, Neurocrine agreed to assume responsibility for development, manufacturing and commercialization activities for such 2019 Neurocrine Program from us and to pay milestones and royalties on future net sales as described further below. For the FA Program, we were granted the option, or the 2019 Co-Co Option, to co-develop and co-commercialize the FA Program upon the occurrence of a specified event, or the 2019 Co-Co Trigger Event. We agreed, were we to exercise the 2019 Co-Co Option, to enter into a cost- and profit-sharing arrangement with Neurocrine, or the 2019 Co-Co Agreement, and (a) jointly develop and commercialize 2019 Collaboration Products for the FA Program, or 2019 Co-Co Products, (b) share in its costs, profits and losses, and (c) forfeit certain milestones and royalties on net sales in the United States during the effective period of the 2019 Co-Co Agreement. The 2019 Transition Event with respect to the FA Program is our receipt of topline data for the initial Phase 1 clinical trial for an FA Program product candidate. The 2019 Co-Co Trigger Event is the achievement of milestones or metrics specified in the applicable development plan, as determined by the JSC. ​ Under the 2019 Neurocrine Collaboration Agreement, subject to exceptions specified, we and Neurocrine agreed that profits and losses under the 2019 Co-Co Option would be allocated 60% to Neurocrine and 40% to us for a 2019 Collaboration Product. The parties agreed that the 2019 Co-Co Agreement would provide us the right to terminate for any reason upon prior written notice to Neurocrine and Neurocrine the right to terminate in certain circumstances upon our change of control. ​ Governance Our research and development activities under the 2019 Neurocrine Collaboration Agreement are to be conducted pursuant to plans agreed to by the parties, on a program-by-program basis, and overseen by the JSC, which is composed of an equal number of representatives from the parties. The JSC may delegate matters within its authority to subcommittees of the JSC. In addition, the 2019 Neurocrine Collaboration Agreement establishes working groups to handle specified matters on a subject matter-by-subject matter basis. If a working group or subcommittee cannot agree 21 Table of Contents on a matter within its purview within a specified time, such matter is to be referred sequentially to the JSC and then the executive officers of the parties. If the executive officers are not able to resolve the matter, then with respect to the FA Program, subject to specified exceptions, (i) Neurocrine has the right to resolve such matter prior to our exercise of the 2019 Co-Co Option with regard to an applicable 2019 Co-Co Product or if the 2019 Co-Co Option expires or goes unexercised and (ii) following the timely exercise by us of the 2019 Co-Co Option, depending on the subject of such matter, either Neurocrine, in certain instances, or the parties jointly or the JSC, in other instances, would have the right to resolve such matter. Manufacturing ​ Prior to the 2019 Transition Event for a 2019 Neurocrine Program, we are responsible for the manufacture of any 2019 Collaboration Products for the 2019 Neurocrine Program. Following the Transition Event, the parties shall negotiate the manufacturing and supply responsibilities, subject to the terms of the 2019 Co-Co Agreement, if applicable. ​ Financial Terms ​ Under the terms of the 2019 Neurocrine Collaboration Agreement, Neurocrine paid us an upfront payment of $115.0 million. In connection with the 2019 Neurocrine Collaboration Agreement, Neurocrine also paid us $50.0 million as consideration for an equity purchase of 4,179,728 shares of our common stock. The 2019 Neurocrine Collaboration Agreement provides for aggregate development milestone payments from Neurocrine to us for 2019 Collaboration Products under the FA Program of up to $195.0 million. We may be entitled to receive aggregate commercial milestone payments for each 2019 Collaboration Product of up to $275.0 million, for a total of up to $550.0 million under the FA Program. The JSC’s selection of the development candidate for the FA Program in February 2024 triggered a $5.0 million milestone payment, which we received in March 2024. We are no longer eligible to receive milestone or royalty payments for the VY-AADC Program or the two 2019 Discovery Programs in light of the partial termination of the 2019 Neurocrine Collaboration Agreement with respect to such programs. ​ Neurocrine has also agreed to pay us royalties, based on future net sales of the 2019 Collaboration Products. Such royalty percentages, for net sales in and outside the United States, as applicable, range from the low-teens to high-teens and high-single digits to mid-teens, for the FA Program. On a country-by-country and program-by-program basis, royalty payments would commence on the first commercial sale of a 2019 Collaboration Product and terminate on the later of (x) the expiration of the last patent covering the 2019 Collaboration Product or its method of use in such country, (y) 10 years from the first commercial sale of the 2019 Collaboration Product in such country and (z) the expiration of regulatory exclusivity in such country, or the 2019 Royalty Term. Royalty payments may be reduced by up to 50% in specified circumstances, including expiration of patents rights related to a 2019 Collaboration Product, approval of biosimilar products in a given country or required payment of licensing fees to third parties related to the development and commercialization of any 2019 Collaboration Product. Additionally, the licenses granted to Neurocrine shall automatically convert to fully paid-up, non-royalty bearing, perpetual, irrevocable, exclusive licenses on a country-by-country and product-by-product basis upon the expiration of the 2019 Royalty Term applicable to such 2019 Collaboration Product in such country. ​ Intellectual Property ​ Under the terms of the 2019 Neurocrine Collaboration Agreement and subject to specified exceptions therein, each party owns the entire right, title and interest in and to all intellectual property rights made solely by its employees or agents in the course of the collaboration. The parties jointly own all rights, title and interest in and to all intellectual property rights made or invented jointly by employees or agents of both parties. ​ Exclusivity ​ During the term of the 2019 Neurocrine Collaboration Agreement, neither party nor any of its respective affiliates is permitted to directly or indirectly exploit any AAV-based gene therapy products directed to a target to which a 2019 Collaboration Product is directed, subject to specified exceptions, including the parties’ conduct of basic research activities. 22 Table of Contents ​ Termination ​ Unless earlier terminated, the 2019 Neurocrine Collaboration Agreement expires on the later of (a) the expiration of the last to expire 2019 Royalty Term with respect to a 2019 Collaboration Product in all countries in the relevant territory or (b) the expiration or termination of all 2019 Co-Co Agreements. Neurocrine may terminate the 2019 Neurocrine Collaboration Agreement in its entirety or on a program-by-program or country-by-country basis by providing at least (x) 180-day advance notice if such notice is provided prior to the first commercial sale of the 2019 Collaboration Product to which the termination applies or (y) one-year advance notice if such notice is provided after the first commercial sale of the 2019 Collaboration Product to which the termination applies. We may terminate the 2019 Neurocrine Collaboration Agreement, subject to specified conditions, if Neurocrine challenges the validity or enforceability of certain of our intellectual property rights. Subject to a cure period, either party may terminate the 2019 Neurocrine Collaboration Agreement in the event of a material breach by the other party in whole or in part, subject to specified conditions. Upon termination in certain cases, Neurocrine has agreed to grant to us licenses to certain Neurocrine intellectual property, subject to a negotiation between the parties to establish royalty rates for use of such intellectual property. In the event of a breach by us with respect to a 2019 Neurocrine Program, if such termination were to occur after a 2019 Transition Event, then (a) if a 2019 Co-Co Agreement is in effect with respect to such program, Neurocrine can terminate the 2019 Co-Co Agreement for such program and we would no longer have co-development and co-commercialization rights with respect to the 2019 Collaboration Product and (b) subject to any license agreements, Neurocrine would no longer have any obligations with respect to any 2019 Collaboration Products resulting from such program. ​ Alexion Option and License Agreement (Formerly Pfizer Option and License Agreement) ​ Summary of Agreement ​ We are party to an option and license agreement, or the Alexion Agreement, with Alexion. We initially entered into the Alexion Agreement with Pfizer, Inc., or Pfizer, on October 1, 2021, or the Alexion Agreement Effective Date. However, Alexion (via Alexion Pharma International Operations Limited, or APIO) later acquired all of Pfizer’s rights under the Alexion Agreement and became the successor-in-interest to Pfizer thereunder effective upon the closing of a definitive purchase and license agreement between Pfizer and Alexion on September 20, 2023. APIO subsequently assigned the Alexion Agreement to its affiliate AstraZeneca Ireland Limited, or AstraZeneca. Neither the acquisition by Alexion nor the subsequent assignment from APIO to AstraZeneca impacted the material terms of the Alexion Agreement. Pursuant to the Alexion Agreement, we have granted Alexion an exclusive, worldwide license, with the right to sublicense, under certain of our intellectual property, the rights to develop and commercialize AAV gene therapy products for the potential treatment of a rare neurological disease comprised of a TRACER Capsid, or the Alexion Licensed Capsid, and a specified transgene, or the Alexion Transgene. We refer to such AAV gene therapy products as Alexion Licensed CNS Products. ​ Prior to Alexion’s acquisition of all of Pfizer’s rights under the Alexion Agreement, we had granted Pfizer the right to exercise up to two options to license TRACER Capsids to develop and commercialize certain AAV gene therapy candidates comprised of a TRACER Capsid and a specified transgene. Effective as of September 30, 2022, Pfizer exercised its option with respect to a TRACER Capsid for a specified transgene for potential treatment of a rare neurological disease. All of Pfizer’s rights in connection with such option exercise were transferred to Alexion as discussed above. Pfizer did not exercise its option with respect to any TRACER Capsid for a specified transgene for the potential treatment of a cardiovascular disease. As result, all rights to any TRACER Capsids for that cardiovascular disease reverted to us in accordance with the terms of the Alexion Agreement. ​ 23 Table of Contents Research Term ​ The Alexion Agreement provides for a research term commencing on the Alexion Agreement Effective Date and expiring on October 1, 2025 (which was initially set to expire on September 30, 2024, but was extended until such date pursuant to the first and second amendments to the Alexion Agreement effective as of September 30, 2024 and March 15, 2025, respectively), or the Alexion Research Term. Until the expiration of the Alexion Research Term, although we were not obligated to conduct additional research activities to identify additional TRACER Capsids that may have been useful for AAV gene therapies for the treatment of rare neurological diseases, we agreed to continue to disclose to Alexion, on a rolling basis, the performance characteristics identified for all such TRACER Capsids, if and when available. During the Alexion Research Term, Alexion conducted additional evaluations of such TRACER Capsids and, on October 1, 2025, exercised its right to substitute another TRACER Capsid for the TRACER Capsid that was originally licensed under the Alexion Agreement. ​ Development, Regulatory Approval and Commercialization ​ Under the Alexion Agreement, Alexion is solely responsible for, and has sole decision-making authority with respect to, development and commercialization of the Alexion Licensed CNS Products. Alexion is required to use commercially reasonable efforts to develop and obtain regulatory approval for at least one Alexion Licensed CNS Product in (a) the United States and (b) at least one of the following countries: the United Kingdom, France, Germany, Italy, Spain and Japan, each of which we refer to as an Alexion Major Market Country, subject to certain limitations. Alexion is also required to use commercially reasonable efforts to commercialize each Alexion Licensed CNS Product in the United States and at least one Alexion Major Market Country where Alexion or its designated affiliates or sublicensees has received regulatory approval for such Alexion Licensed CNS Product, subject to certain limitations. ​ Intellectual Property ​ Under the terms of the Alexion Agreement, each of the parties owns the entire right, title, and interest in and to all patents or know-how controlled by such party and existing as of or before the effective date of the Alexion Agreement, or invented, developed, created, generated or acquired solely by or on behalf of such party after such effective date. ​ Exclusivity ​ Subject to certain specified exceptions, any patents and know-how that are invented or otherwise developed jointly by or on behalf of the parties during the term of the Alexion Agreement and in the course of our and Alexion’s activities under the Alexion Agreement will follow inventorship under U.S. patent law. Subject to certain limitations and exceptions, we have agreed (a) during the Alexion Research Term, not to conduct any internal program or program on behalf of a third party that is directed to development or commercialization of any capsid candidates, or grant any third party or affiliate any right or license under our rights in such capsid candidates to exploit any therapeutic product, in combination with any Alexion Transgene, in any indication for therapeutic, diagnostic and prophylactic human and veterinary use; and (b) not to grant any third party or affiliate any right or license under our patents to exploit any licensed capsid in combination with any Alexion Transgene. ​ Financial Terms ​ Prior to Pfizer’s transfer of its rights under the Alexion Agreement to Alexion, Pfizer paid us an upfront payment of $30.0 million in October 2021, and an additional fee of $10.0 million in connection with its exercise of an option. We are eligible to receive specified development, regulatory, and commercialization milestone payments of up to an aggregate of $115.0 million for the first corresponding Alexion Licensed CNS Product to achieve the corresponding milestone. On an Alexion Licensed CNS Product-by-Alexion Licensed CNS Product basis, we are also eligible to receive (a) specified sales milestone payments of up to an aggregate of $175.0 million per Alexion Licensed CNS Product and (b) tiered, escalating royalties in the mid- to high-single-digit percentages of annual net sales of each Alexion Licensed CNS Product. The royalties are subject to potential reductions in customary circumstances including 24 Table of Contents patent claim expiration, payments for certain third-party licenses, and biosimilar market penetration, subject to specified limits. ​ Termination ​ Unless earlier terminated, the Alexion Agreement expires on the expiration of the last-to-expire royalty term with respect to all Alexion Licensed CNS Products in all countries. Subject to a cure period, either party may terminate the Alexion Agreement, in whole or in part, subject to specified conditions, in the event of the other party’s uncured material breach. Alexion may also terminate the Alexion Agreement, in whole or in part, subject to specified conditions, for our insolvency, the occurrence of a violation of global trade control laws, or for our noncompliance with certain anti-bribery or anti-corruption covenants. Alexion may also terminate the Alexion Agreement, in whole or in part, for any or no reason upon ninety days’ written notice to us. ​ Upon certain terminations for cause by Alexion, the license that we have granted to Alexion under the Alexion Agreement shall become irrevocable and perpetual, and all milestone payments and royalties that would have otherwise been payable by Alexion under such license had the Alexion Agreement remained in effect would be substantially reduced. ​ License Agreement with Touchlight IP Limited On November 3, 2022, we and Touchlight IP Limited, or Touchlight, entered into a license agreement, or the Touchlight License Agreement, to authorize historical use by us of a certain DNA preparation process, or the Subject DNA Preparation Process, and to authorize the prospective exploitation of TRACER Capsids created with the use of the Subject DNA Preparation Process. ​ The terms of the Touchlight License Agreement include a one-time, non-refundable technology access fee of $5.0 million, paid to Touchlight during the fourth quarter of 2022. ​ The terms of the Touchlight License Agreement also include future milestone payments and low single-digit royalties payable to Touchlight by us if we or our program collaborators or licensees choose to utilize in a therapeutic product certain TRACER Capsids that were created with the historical use of the Subject DNA Preparation Process. Additionally, we are obligated to pay low single-digit royalties to Touchlight on future payments we receive in connection with licensing of certain TRACER Capsids that were created with the historical use of the Subject DNA Preparation Process, excluding the licensing of or collaboration on any of our therapeutic programs. License Agreement with Transition Bio We and Transition Bio, Inc., or Transition Bio, entered into a research collaboration, option and license agreement, or the Transition Bio Agreement, with an effective date of June 26, 2025. The Transition Bio Agreement superseded a prior agreement between us and Transition Bio dated December 24, 2024. Under the terms of the agreement, Transition Bio is responsible for the discovery and optimization of small molecules targeting TDP-43 until nomination of a development candidate, upon which we will have an option to license the worldwide exclusive rights to develop and commercialize the program. The Transition Bio Agreement contains a termination for convenience clause which allows for either party to terminate the arrangement for any reason or no reason upon sixty days prior written notice. In the event that we terminate the Transition Bio Agreement due to a change in control, we are obligated to pay Transition Bio up to $2.0 million in termination fees. ​ We paid Transition Bio a low single-digit million dollar upfront payment during the year ended December 31, 2024 in connection with a prior agreement. During the fourth quarter of 2025, we paid Transition Bio an additional low single-digit million dollar payment for the achievement of a research milestone. Transition Bio is eligible to receive potential research, development, commercial and net sales milestone payments totaling up to $500.0 million. Transition Bio is also eligible for high single-digit to low double-digit royalties on net sales during the royalty term of up to ten years. 25 Table of Contents Competition The biopharmaceutical industry is characterized by intense and dynamic competition to develop new technologies and proprietary therapies. Any product candidates that we successfully develop into products and commercialize may compete with existing therapies and new therapies that may become available in the future. While we believe that our gene therapy platform, product programs, product candidates and scientific expertise in the fields of gene therapy and neuroscience provide us with competitive advantages, we face potential competition from various sources, including larger and better-funded pharmaceutical, specialty pharmaceutical and biotechnology companies, as well as from academic institutions, governmental agencies and public and private research institutions. We expect that our TRACER discovery platform, non-viral therapeutics platform, and clinical and preclinical programs will compete with a variety of therapies in development, including: ● Our anti-tau antibody program for AD will potentially compete with tau antibodies being developed by Lundbeck LLC, Merck & Co., Inc. in collaboration with Teijin Limited, Eisai Co., Ltd., Janssen Pharmaceuticals, Inc., a subsidiary of Johnson & Johnson, UCB S.A., Bristol-Myers Squibb Company in collaboration with Prothena Corporation plc, along with several other companies; ● Our tau silencing gene therapy program for AD will potentially compete with an antisense oligonucleotide program being developed by Ionis Pharmaceuticals, Inc. in collaboration with Biogen Inc.; ● Our TDP-43 small molecule will potentially compete with a variety of companies developing small-molecules for TDP-43, including: Dewpoint Therapeutics, Inc., WaveBreak Therapeutics, LLC, Molefy Pharma SL, and various academic groups; ● Our TRACER discovery platform will potentially compete with a variety of companies developing AAV capsids, including: 4D Molecular Therapeutics, Inc., Affinia Therapeutics Inc., Apertura Gene Therapy, LLC, Capsida Biotherapeutics, Inc., Capsigen, Inc., Dyno Therapeutics, Inc., Kate Therapeutics Inc. (acquired by Novartis), Sangamo Therapeutics , Inc., and Shape Therapeutics Inc .; and ​ ● O ur non-viral therapeutics platform will potentially compete with a variety of companies developing non-viral shuttles for the delivery of genetic medicines to the CNS, including: ABL Bio, Inc. in collaboration with Sanofi S.A. and separately in collaboration with GSK plc, Aliada Therapeutics, Inc. (acquired by AbbVie Inc.), Arrowhead Pharmaceuticals, Inc. in collaboration with Sarepta Therapeutics, Inc., BioArctic AB in collaboration with Eisai Co., Ltd., Denali Therapeutics Inc., F. Hoffmann-La Roche Ltd, JCR Pharmaceuticals Co., Ltd., Manifold Biotechnologies, Inc. in collaboration with F. Hoffman-La Roche Ltd., and Souffle Therapeutics, Inc. We are aware of several companies focused on developing AAV gene therapies in various indications, including Abeona Therapeutics Inc., Adverum Biotechnologies, Inc., Akouos, Inc. (acquired by Eli Lilly and Company, or Eli Lilly), Asklepios BioPharmaceutical, Inc. (acquired by Bayer AG), Astellas Gene Therapies, Inc., Beacon Therapeutics Holdings Limited, Biogen Inc., BioMarin Pharmaceutical Inc., Encoded Therapeutics, Inc., GenSight Biologics S.A., LEXEO Therapeutics, Inc., LogicBio Therapeutics, Inc. (acquired by AstraZeneca), MeiraGTx Ltd., Neurogene Inc., Novartis Gene Therapies, Inc. (formerly AveXis, Inc.), Passage Bio, Inc., Pfizer Inc., Prevail Therapeutics Inc. (acquired by Eli Lilly), REGENXBio Inc., Sarepta Therapeutics, Inc., Solid Biosciences Inc., Spark Therapeutics, Inc. (acquired by Genentech, Inc.), Taysha Gene Therapies, Inc. and uniQure, Inc., as well as several companies addressing other methods for modifying genes and regulating gene expression. Any advances in gene therapy technology made by a competitor may be used to develop therapies that could compete against any of our product candidates. ​ Many of our competitors, either alone or with their strategic partners, have substantially greater financial, technical and human resources than we do and significantly greater experience in the discovery and development of product candidates, obtaining FDA and other regulatory approvals of product candidates and commercializing those 26 Table of Contents product candidates. Accordingly, our competitors may be more successful than us in obtaining approval for product candidates and achieving widespread market acceptance. Our competitors’ product candidates may be more effective, or more effectively marketed and sold, than any product candidate we may commercialize and may render our treatments obsolete or non-competitive before we can recover the expenses of developing and commercializing any of our product candidates. ​ Mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and subject registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. ​ We anticipate that we will face intense and increasing competition as new product candidates enter the market and advanced technologies become available. We expect any product candidates that we develop and commercialize to compete on the basis of, among other things, efficacy, safety, convenience of administration and delivery, price, and the availability of reimbursement from government and other third-party payers. ​ Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their product candidates more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. ​ Manufacturing ​ The manufacture of gene therapy, non-viral therapeutic, and other biological products is technically complex, and necessitates substantial expertise and capital investment. Production difficulties caused by unforeseen events may delay the availability of material for our clinical studies. To meet the requirements of our current and planned future AAV gene therapy trials we have developed a proprietary HEK 293 transient transfection manufacturing process that is scalable for large scale AAV manufacturing – both for preclinical research activities and clinical and commercial manufacturing. We continuously innovate and develop advanced manufacturing technologies to enable high yields and product quality, and we manufacture preclinical AAV material for large animal studies at our onsite, state-of-the-art chemistry, manufacturing, and controls, or CMC, development facility. Our current AAV gene therapy manufacturing process has been transferred to our contract manufacturing organizations to enable clinical current good manufacturing practice, or cGMP manufacturing. ​ We presently contract with third parties for the manufacturing of our program materials. We currently have no plans to build our own clinical or commercial scale cGMP manufacturing capabilities. The use of contract manufacturing and reliance on collaboration partners is relatively cost-efficient and we believe that it eliminates the need for our direct investment in manufacturing facilities and additional staff early in development. Although we expect to rely on contract manufacturers, we have personnel with manufacturing and quality experience to oversee our contract manufacturers. ​ Intellectual Property ​ Overview ​ We strive to protect the proprietary technology, inventions, and know-how to enhance improvements that are commercially important to the development of our business, including seeking, maintaining, and defending patent rights, whether developed internally or licensed from third parties. We also rely on trade secrets and know-how relating to our proprietary technology platform, on continuing technological innovation and on in-licensing opportunities to develop, improve and maintain the strength of our position in the field of neurogenetic medicines and gene therapy that may be important for the development of our business. We additionally may rely on regulatory protection afforded through data exclusivity, market exclusivity and patent term extensions where available. 27 Table of Contents ​ Our commercial success may depend in part on our ability to: obtain and maintain patent and other protections for commercially important technology, inventions and know-how related to our business; defend and enforce our patents; preserve the confidentiality of our trade secrets and know-how; and operate without infringing the valid and enforceable patents and intellectual property rights of third parties. Our ability to stop third parties from making, having made, using, selling, offering to sell or importing our products may depend on the extent to which we have rights under valid and enforceable licenses and patents that cover these activities. In some cases, these rights may need to be enforced by third-party licensors. With respect to both licensed and company-owned intellectual property, we cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications filed by us in the future, nor can we be sure that any of our existing patents or any patents that may be granted to us in the future will be commercially useful in protecting our commercial products and methods of using or manufacturing the same. ​ We own at least 359 pending patent applications and at least 92 patents have issued in the United States and foreign jurisdictions. We co-own at least 20 pending patent applications and at least 23 patents have issued from these co-owned families in the United States and foreign jurisdictions. At least six patent applications have been filed and are pending in the United States and foreign jurisdictions by or on behalf of universities which have granted us exclusive license rights to the technology. To date, at least 28 patents have issued to our licensors which have granted us exclusive license rights to the technology. To date, at least 63 patents have issued to our licensors which have granted us non-exclusive license rights to the technology with at least 32 applications pending. Our policy is to file patent applications to protect technology, inventions and improvements to inventions that are commercially important to the development of our product candidates and business. We seek U.S. and international patent protection for a variety of technologies, including: AAV-based biological products and constructs, antibodies, non-viral therapeutic modalities, methods of delivering said AAV-based biological products and constructs, antibodies and non-viral modalities, methods of treating diseases of interest, as well as methods of engineering and manufacturing of the same. We also intend to seek patent protection or rely upon know-how and trade secret rights to protect other technologies that may be used to discover and validate targets and that may be used to identify and develop novel biological products. We seek protection, in part, through confidentiality and proprietary information agreements. We are a party to various other license agreements that give us rights to use specific technologies in our research and development. ​ Company-Owned Intellectual Property ​ Tauopathies ​ We own nine pending patent families directed to antibodies to tau and vectorized forms thereof with 40 pending non-provisional patent applications, two granted patents, and one provisional application. Patents that grant from these families are generally expected to commence expiration in 2037, with some later filed applications commencing expiration in 2040, 2041, 2042, 2043, 2044, and 2045 all of which are subject to possible patent term extensions. ​ We own five pending patent families to RNA inhibitors for treating tauopathies with 34 pending non-provisional patent applications. Patents that grant from this family are generally expected to commence expiration in 2043, 2044, 2045, and 2046, subject to possible patent term extensions. ​ Friedreich’s Ataxia ​ We own six pending patent families with six granted patents and 28 patent applications and we co-own one pending patent family with five patent applications and three granted patents directed to AAVs encoding frataxin constructs for the treatment of FA. Patents that grant from these patent families are generally expected to commence expiration in 2036, with some later filed applications commencing expiration in 2038, 2039, 2040, and 2044, all of which are subject to possible patent term extensions. ​ 28 Table of Contents GBA1 Gene Therapy ​ We own nine pending patent families with 67 pending non-provisional patent applications and one pending provisional application directed to AAVs encoding GBA1 for the treatment of PD, Gaucher disease, and dementia with Lewy Bodies. Patents that grant from this patent family are expected to commence expiration in 2041, 2042, 2043, 2044, 2045, and 2046, subject to possible patent term extensions. ​ Huntington’s Disease ​ We own two pending patent families with two granted patents directed to pharmaceutical compositions and methods for targeting HTT for the treatment of Huntington’s disease. Patents from this family are generally expected to commence expiration in 2037, all of which are subject to possible patent term extensions. Capsids ​ We own two patent families pending in the United States and foreign jurisdictions that are directed to the TRACER discovery platform for selection of AAV capsids with BBB crossing and cell-specific transduction properties. In these two pending patent families directed to the TRACER discovery platform, there are five granted patents and 10 pending applications, which are generally expected to commence expiration in 2039 and 2041, respectively, subject to possible patent term extensions. ​ We also own 12 pending patent families comprising 82 pending U.S. and foreign applications and five granted patents, as well as two pending provisional application directed to capsid variants identified using the TRACER discovery platform showing improved properties over their wild-type AAV counterparts. Patents that grant from these patent families and pending provisional applications are generally expected to commence expiration in 2041, 2042, 2043, 2044, and 2045, subject to possible patent term extensions. ​ We own at least eight patent families comprising 56 pending non-provisional applications and we co-own two patent families comprising six pending non-provisional applications directed to constructs containing TRACER Capsids in combination with specific payloads for treatment of CNS and other indications. Patents that grant from these pending provisional and non-provisional applications are generally expected to commence expiration in 2042, 2043, 2044, 2045, 2046, and 2047, subject to possible patent term extensions. ​ We also own one patent family pending in the United States and foreign jurisdictions directed to capsid variants generated using other methodologies. In this pending patent family, there are four granted patents and 9 pending patent applications. Patents that grant from this patent family are generally expected to commence expiration in 2038, subject to possible patent term extensions. ​ Non-Viral Therapeutics ​ We own two pending patent families with eight pending non-provisional patent applications and two pending non-provisional applications directed to ligands to capsid receptors. Patents that grant from these pending non-provisional applications are generally expected to commence expiration in 2044 and 2046, subject to possible patent term extensions. ​ Vector Engineering ​ We own three patent families with 64 granted patents (including 21 patents in European countries) and 23 patent applications directed to engineering of the vector genome. Patents that grant from these patent families are generally expected to commence expiration in 2035, 2037, and 2038, which are all subject to possible patent term extensions. ​ 29 Table of Contents Other ​ We own five patent families and have four granted patents and one pending non-provisional patent applications directed to targeting SOD1 for the treatment of ALS. Patents that grant from these patent families are generally expected to commence expiration in 2035, with some applications expiring in 2038 and 2044, all of which are subject to possible patent term extensions. ​ We co-own two pending patent families directed to trajectory array delivery devices and methods of use. The first pending patent family has one granted patent, and the second pending patent family has four granted patents and three pending patent applications. Patents that grant from these patent families are generally expected to commence expiration in 2037 and 2038, subject to possible patent term extensions. ​ We own one pending patent family with one pending non-provisional patent application directed to AAVs encoding NPC1. Patents that grant from this patent family are expected to commence expiration in 2041, subject to possible patent term extensions. ​ We own one pending patent family with one pending provisional patent application and one pending provisional application directed to AAVs encoding a specific CNS payload. Patents that grant from this patent family are expected to commence expiration in 2046, subject to possible patent term extensions. ​ We co-own one pending patent family with 15 granted patents and six pending patent applications directed to AAV production and CMC. Patents that grant from this patent family are generally expected to commence expiration in 2037, subject to possible patent term extensions. ​ Licensed Intellectual Property ​ We have obtained exclusive licenses and non-exclusive licenses to patents directed to both compositions of matter and methods of use. ​ We have licensed three families of patents and patent applications, in the field of gene therapy for human diseases, directed to RNAi constructs as vector payloads, their design and use in the treatment of neurological disorders from the University of Massachusetts. Two of the three families of patents and applications are exclusively licensed and comprise 14 granted patents and four pending applications. One of the three families of patents and applications are non-exclusively licensed and comprise one granted patent in the United States. Patents that grant from these patent families are generally expected to expire between 2026 and 2036, subject to possible patent term extensions. ​ We have exclusively licensed one family of patents and patent applications directed to AAV capsids from the University of Massachusetts. In this pending patent family, there are 14 granted patents and two pending patent applications. Patents that grant from this patent family are generally expected to commence expiration in 2031, subject to possible patent term extensions. ​ We have non-exclusively licensed two pending patent families from Ablexis, LLC. These families of patents and patent applications are pending and/or granted in the United States and other territories and comprise 52 granted patents and one pending application. Patents that grant from these patent families are generally expected to expire between 2029 and 2031, subject to possible patent term extensions. ​ We have non-exclusively licensed two pending patent families directed to AAV capsids from the California Institute of Technology. These families of patents and patent applications are pending in the United States and internationally and comprise seven granted patents and one pending application. Patents have been granted in the United States. Patents that grant from these patent families are generally expected to commence expiration in 2034 and 2036, subject to possible patent term extensions. ​ We have non-exclusively licensed three pending patent families directed to microRNA detargeting from the University of Pennsylvania. These families of patent applications are pending in the United States and internationally 30 Table of Contents and comprise at least 30 applications and three granted patents. Patents that grant from these patent families are generally expected to commence expiration in 2039, 2041, and 2042, subject to possible patent term extensions. ​ Trademark Protection ​ We own registered trademarks and service marks, as well as pending trademarks and service mark applications in the United States and a number of other countries for the in the marks VOYAGER, VOYAGER (with design elements), VOYAGER THERAPEUTICS and VOYAGER THERAPEUTICS (with design elements), which we presently use or may use in connection with our pharmaceutical research and development services and our biological preparations for gene therapy for the treatment of various diseases. ​ We also own registrations in the United States and United Kingdom for the mark TRACER for services including, among others, “research and development of platform technologies for genetic delivery of therapies and pharmaceutical via adeno-associated virus (AAV) capsids.” ​ In addition, we have pending trademark and service mark applications in the United States for the marks VOYAGER NEUROSHUTTLE and NEUROSHUTTLE, which we presently use or may use in connection with biotechnology research services and pharmaceutical products and therapeutics for the treatment of diseases and disorders, among other uses. ​ In connection with the ongoing development and advancement of our products and services in the U.S. and in various international jurisdictions, we routinely seek to create protection for our marks and enhance their value by pursuing trademarks and service marks where available and when appropriate. We plan to register trademarks in connection with our biological products. ​ Protection of Confidential Information, Know-how and Trade Secrets ​ We may rely, in some circumstances, on confidential information, know-how and trade secrets to protect our technology. We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. We also seek to preserve the integrity and confidentiality of our data, know-how and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our confidential information, know-how and trade secrets may otherwise become known or be independently discovered by competitors. To the extent that our consultants, contractors or collaborators use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions. ​ Government Regulation ​ The research, development, testing, manufacture, quality control, packaging, labeling, storage, record-keeping, distribution, import, export, promotion, advertising, marketing, sale, pricing and reimbursement of biologic products are extensively regulated by governmental authorities in the United States and other countries. The processes for obtaining regulatory approvals in the United States and in foreign countries and jurisdictions, along with compliance with applicable statutes and regulations and other regulatory requirements, both pre-approval and post-approval, require the expenditure of substantial time and financial resources. The regulatory requirements applicable to biological product development, approval and marketing are subject to change, and regulations and administrative guidance often are revised or reinterpreted by the agencies in ways that may have a significant impact on our business. ​ 31 Table of Contents U.S. Government Regulation ​ U.S. Biological Products Development Process ​ In the United States, the FDA approves and regulates gene therapy and antibody products as biological products, or biologics. These products are licensed for marketing under the Public Health Service Act, or the PHSA, and regulated under the Federal Food, Drug, and Cosmetic Act, or FDCA. A company, institution, or organization which takes responsibility for the initiation and management of a clinical development program for such products, and for their regulatory approval, is typically referred to as a sponsor. ​ The process required by the FDA before a biological product may be marketed in the United States generally involves the following: ​ ● completion of nonclinical laboratory tests and animal studies according to the FDA’s good laboratory practices, or GLPs, and applicable requirements for the humane use of laboratory animals or other applicable regulations; ​ ● preparation of clinical trial material in accordance with cGMPs; ​ ● design of a clinical protocol and submission to the FDA of an application for an IND, which must become effective before human clinical trials may begin; ​ ● approval by an independent institutional review board, or IRB, or ethics committee representing each clinical trial site before each clinical trial may be initiated; ​ ● performance of adequate and well-controlled human clinical trials according to the FDA’s good clinical practices, or GCPs, and any additional requirements for the protection of human research subjects and their health information, to establish the safety, purity, potency, and efficacy of the proposed biological product for its intended use; ​ ● submission to the FDA of a biologics license application, or BLA, for marketing approval that includes substantive evidence of safety, purity, and potency from results of nonclinical testing and clinical studies, including payment of application user fees; ​ ● satisfactory completion of an FDA inspection prior to BLA approval of the manufacturing facility or facilities where the biological product is produced to assess compliance with cGMP, to assure that the facilities, methods and controls are adequate to preserve the biological product’s identity, strength, quality and purity; ​ ● potential FDA inspection of the nonclinical and clinical study sites that generated the data in support of the BLA; ​ ● potential FDA Advisory Committee meeting to elicit expert input on critical issues; ​ ● p ayment of user application and program fees pursuant to the Prescription Drug User Fee Act, or PDUFA; ​ ● FDA review and approval of the BLA , authorizing licensure of the biological product for marketing of the product in the US for one or more indications ; and ​ ● compliance with any post approval requirements, including the potential requirement to implement a Risk Evaluation and Mitigation Strategy, or REMS, and the potential requirement to conduct post approval studies. ​ 32 Table of Contents Preclinical Studies ​ Before a sponsor begins testing a product candidate with potential therapeutic value in humans, the product candidate enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, formulation and stability, as well as other studies to evaluate, among other things, the toxicity of the product candidate. These studies are generally referred to as IND-enabling studies. The conduct of the preclinical tests and formulation of the compounds for testing must comply with federal regulations and requirements, including GLP regulations and standards. With the passage of the FDA’s Modernization Act 2.0 in December 2022, Congress eliminated provisions in both the FDCA and the PHSA that required animal testing in support of a new drug application, or NDA, or a BLA. While animal testing may still be conducted, the FDA was authorized to rely on alternative non-clinical tests, including cell-based assays, microphysiological systems, or bioprinted or computer models. In April 2025, the FDA released a roadmap to replace animal testing in preclinical safety studies with scientifically validated new approach methodologies. The results of the preclinical tests, together with manufacturing information and analytical data, are submitted to the FDA as part of an IND. Some long-term preclinical testing, such as animal tests of reproductive adverse events and carcinogenicity, and long-term toxicity studies, may continue after the IND is submitted. ​ The IND and IRB Processes ​ An IND is an exemption from the FDCA that allows an unapproved product candidate to be shipped in interstate commerce for use in an investigational clinical trial and a request for FDA authorization to administer such investigational product to humans. An IND must be secured prior to interstate shipment and administration of any product candidate that is not the subject of an approved NDA or a BLA. In support of a request for an IND, sponsors must submit a protocol for each clinical trial and any subsequent protocol amendments must be submitted to the FDA as part of the IND. An IND automatically becomes effective 30 days after receipt by the FDA, unless before that time the FDA raises concerns or questions related to one or more proposed clinical trials or studies and places the trial on a clinical hold. The FDA may also place a hold or partial hold on a clinical study based on chemistry, manufacturing, and controls issues involving the investigational product. In either case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial may proceed. As a result, submission of an IND may not result in the FDA allowing clinical trials to commence. ​ Following commencement of a clinical trial under an IND, the FDA may also place a clinical hold or partial clinical hold on that trial. A clinical hold is an order issued by the FDA to the sponsor to delay a proposed clinical investigation or to suspend an ongoing investigation. A partial clinical hold is a delay or suspension of only part of the clinical work requested under the IND. For example, a partial clinical hold might state that a specific protocol or part of a protocol may not proceed, while other parts of a protocol or other protocols may do so. No more than 30 days after the imposition of a clinical hold or partial clinical hold, the FDA will provide the sponsor a written explanation of the basis for the hold. Following the issuance of a clinical hold or partial clinical hold, a clinical investigation may only resume once the FDA has notified the sponsor that the investigation may proceed. The FDA will base that determination on information provided by the sponsor correcting the deficiencies previously cited or otherwise satisfying the FDA that the investigation can proceed or recommence. Occasionally, clinical holds are imposed due to manufacturing issues that may present safety issues for the clinical study subjects. ​ An IRB representing each institution participating in the clinical trial must also review and approve the plan for any clinical trial before it commences at that institution, and the IRB must conduct continuing review and reapprove the study at least annually. The IRB, which must operate in compliance with Health and Human Services, or HHS, and FDA regulations, must review and approve, among other things, the study protocol and informed consent information to be provided to study subjects before the study can commence at the institution and must monitor the trial until completed. An IRB can suspend or terminate approval of a clinical trial at its institution, or an institution it represents, if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the product candidate has been associated with unexpected serious harm to patients. ​ Additionally, some trials are overseen by an independent group of qualified experts organized by the trial sponsor, known as a data monitoring committee, or DMC. This group provides an independent recommendation as to whether or not a trial may move forward at designated checkpoints based on review of available data from the study, to 33 Table of Contents which only the DMC maintains access. Suspension or termination of development during any phase of a clinical trial can occur if the DMC recommends stopping a trial due to safety or efficacy. ​ Human Clinical Trials ​ Clinical trials involve the administration of the investigational product candidate to human subjects under the supervision of a qualified investigator in accordance with GCP requirements which include, among other things, the requirement that all research subjects provide their informed consent in writing before they participate in any clinical trial. Clinical trials are conducted under written clinical trial protocols detailing, among other things, the objectives of the trial, inclusion and exclusion criteria, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. Each protocol, and any subsequent material amendment to the protocol, must be submitted to the FDA as part of the IND, and progress reports detailing the status of the clinical trials must be submitted to the FDA annually. ​ Human clinical trials are typically conducted in three sequential phases, but the phases may overlap or be combined. Additional studies may also be required after approval. ​ Phase 1 clinical trials are initially conducted in a limited population, which may be healthy volunteers or subjects with the target disease, to test the product candidate for safety, including adverse effects, dose tolerance, absorption, metabolism, distribution, excretion and pharmacodynamics in healthy humans or in patients. During Phase 1 clinical trials, information about the product candidate’s pharmacokinetics and pharmacological effects may be obtained. ​ Phase 2 clinical trials are generally conducted in a patient population to identify possible adverse effects and safety risks, evaluate the efficacy of the product candidate for specific targeted indications and determine dose tolerance and optimal dosage. Multiple Phase 2 clinical trials may be conducted by the sponsor to obtain information prior to beginning larger and more costly Phase 3 clinical trials. ​ Phase 3 clinical trials proceed if the prior clinical trials demonstrate that the product candidate is potentially effective and has an acceptable safety profile. Phase 3 clinical trials are undertaken in the proposed patient population to provide evidence of clinical efficacy and safety. A well-controlled, statistically robust Phase 3 clinical trial is designed to deliver the data that regulatory authorities will use to decide whether or not to approve the product candidate, and, if approved, how to appropriately label a new biologic product. Such Phase 3 clinical trials are referred to as “pivotal” trials. ​ A clinical trial may combine the elements of more than one phase and the FDA often requires more than one Phase 3 trial to support marketing approval of a product candidate. A company’s designation of a clinical trial as being of a particular phase is not necessarily indicative that the study will be sufficient to satisfy the FDA requirements of that phase because this determination cannot be made until the protocol and data have been submitted to and reviewed by the FDA. Moreover, as noted above, a pivotal trial is a clinical trial that is believed to satisfy FDA requirements for the evaluation of a product candidate’s safety and efficacy such that it can be used, alone or with other pivotal or non-pivotal trials, to support regulatory approval. Generally, pivotal trials are Phase 3 trials, but they may be Phase 2 trials if the design provides a well-controlled and reliable assessment of clinical benefit, particularly in an area of unmet medical need or rare patient population. ​ In December 2022, with the passage of the Food and Drug Omnibus Reform Act, or FDORA, Congress required sponsors to develop and submit a diversity action plan, or DAP, for each Phase 3 clinical trial or any other “pivotal study” of a new drug or biological product. These plans are meant to encourage the enrollment of more diverse patient populations in late-stage clinical trials of FDA-regulated products. Specifically, action plans must include the sponsor’s goals for enrollment, the underlying rationale for those goals, and an explanation of how the sponsor intends to meet them. In June 2024, as mandated by FDORA, the FDA issued draft guidance outlining the general requirements for DAPs. On January 27, 2025, in response to an Executive Order issued by President Trump on January 21, 2025, on diversity, equity and inclusion programs, the FDA removed this draft guidance from its website. Subsequently, in July 2025, pursuant to a court order, the FDA restored the draft DAP guidance to its website with a statement that “information on this page may be modified and/or removed in the future subject to the terms of the court’s order and implemented consistent with applicable law.” Accordingly, in light of these ongoing actions, there is considerable 34 Table of Contents uncertainty surrounding the draft DAP guidance and how the FDA will consider DAPs in connection with its review of BLAs. ​ In some cases, the FDA may approve an NDA or BLA for a product candidate but require the sponsor to conduct additional clinical trials to further assess the product candidate’s safety and effectiveness after approval. Such post-approval trials, typically referred to as post-marketing studies or clinical trials, may be conducted after initial marketing approval. These trials are used to either gain additional experience from the treatment of a larger number of patients in the intended treatment group or to evaluate a specific outcome of interest (safety or efficacy). In certain instances, the FDA may mandate the performance of post-marketing studies or clinical trials, such as to verify clinical benefit in the case of products approved under accelerated approval regulations. Failure to exhibit due diligence with regard to conducting mandatory post-marketing studies or clinical trials could result in withdrawal of FDA approval for products. ​ In September 2025, the FDA issued final guidance with updated recommendations for GCPs aimed at modernizing the design and conduct of clinical trials. The updates are intended to help pave the way for more efficient clinical trials to facilitate the development of medical products. The final guidance is adopted from the International Council for Harmonisation’s recently updated E6(R3) final guideline that was developed to enable the incorporation of rapidly developing technological and methodological innovations into the clinical trial enterprise. In addition, the FDA issued final guidance outlining recommendations for the implementation of decentralized clinical trials. ​ In October 2025, the FDA issued final guidance that focuses on patient-focused drug development. The guidance outlines how stakeholders, such as patients, caregivers, researchers and medical product developers, can submit patient experience data in support of the development and approval of drug products. To that end, the guidance provides an overview of clinical outcome assessments, or COAs, in clinical trials, and the role that COAs may play in evaluating the clinical benefit of a medical product. ​ Finally, sponsors of clinical trials are required to register and disclose certain clinical trial information on a public registry (clinicaltrials.gov) maintained by the U.S. National Institutes of Health, or NIH. In particular, information related to the product, patient population, phase of investigation, study sites and investigators and other aspects of the clinical trial is made public as part of the registration of the clinical trial. The NIH’s Final Rule on registration and reporting requirements for clinical trials became effective in 2017. The Final Rule also implemented reporting requirements for results of clinical trials listed on clinicaltrials.gov. Although the FDA has historically not enforced these reporting requirements, the FDA has, as of January 31, 2026, issued eight notices of non-compliance, thereby signaling the government’s willingness to begin enforcing these requirements against non-compliant clinical trial sponsors. While these notices of non-compliance did not result in civil monetary penalties, the failure to submit clinical trial information to clinicaltrials.gov is a prohibited act under the FDCA with violations subject to potential civil monetary penalties of up to $10,000 for each day the violation continues. Violations may also result in injunctions and/or criminal prosecution or disqualification from federal grants. ​ Clinical Studies Outside of the United States in Support of FDA Approval ​ In connection with the clinical development of our programs, we may conduct trials at sites outside of the United States. When a foreign clinical study is conducted under an IND, all IND requirements must be met unless waived. When a foreign clinical study is not conducted under an IND, the sponsor must ensure that the study complies with certain regulatory requirements of the FDA in order to use the study as support for an NDA or a BLA. Specifically, the studies must be conducted in accordance with GCPs, including undergoing review and receiving approval by an independent ethics committee and seeking and receiving informed consent from subjects. GCP requirements encompass both ethical and data integrity standards for clinical studies. The FDA’s regulations are intended to help ensure the protection of human subjects enrolled in non-IND foreign clinical studies, as well as the quality and integrity of the resulting data. They further help ensure that non-IND foreign studies are conducted in a manner comparable to that required for IND studies. ​ The acceptance by the FDA of study data from clinical trials conducted outside the United States in support of United States approval may be subject to certain conditions or may not be accepted at all. In cases where data from 35 Table of Contents foreign clinical trials are intended to serve as the sole basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. ​ In addition, even where the foreign study data are not intended to serve as the sole basis for approval, the FDA will not accept the data as support for an application for marketing approval unless the study is well-designed and well-conducted in accordance with GCP requirements and the FDA is able to validate the data from the study through an onsite inspection if deemed necessary. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials are subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. ​ Interactions with the FDA During the Clinical Development Program ​ Following the clearance of an IND and the commencement of clinical trials, a sponsor is given the opportunity to meet with the FDA at certain points in the clinical development program. There are five types of meetings that occur between sponsors and the FDA. Type A meetings are those that are necessary for an otherwise stalled product development program to proceed or to address an important safety issue. Type B meetings include pre-IND and pre-NDA meetings as well as end of phase meetings such as end of Phase 2, or EOP2, meetings. A Type C meeting is any meeting other than a Type A or Type B meeting regarding the development and review of a product. A Type D meeting is focused on a narrow set of issues and should not require input from more than three disciplines or divisions. Finally, INTERACT meetings are intended for novel products and development programs that present unique challenges early in the development of an investigational product. ​ At the conclusion of these meetings, the FDA will typically provide its responses to questions posed by the sponsor regarding the clinical development program. The FDA will not indicate whether an NDA or BLA will be approved, but it will provide guidance to the sponsor on various questions, including whether an application should be submitted in the first place on the basis of the studies and data proposed by the sponsor. The agency may also generally express support for the sponsor’s approach in the clinical development program but indicate that questions concerning whether the data support approval will be subject to review by the agency following its acceptance for filing of the NDA or BLA. The FDA has indicated that its responses, as conveyed in meeting minutes and advice letters, only constitute mere recommendations and/or advice made to a sponsor and, as such, sponsors are not bound by such recommendations and/or advice. Nonetheless, from a practical perspective, a sponsor’s failure to follow the FDA’s recommendations for design of a clinical program may put the program at significant risk of failure. ​ Gene Therapy Products ​ We expect that the procedures and standards applied to gene therapy products will be applied to any gene therapy product candidates we may develop. The FDA has defined a gene therapy product as one that seeks to modify or manipulate the expression of a gene or to alter the biological properties of living cells for therapeutic use. Within the FDA, the Center for Biologics Evaluation and Research, or CBER, regulates gene therapy products. Within CBER, the review of gene therapy and related products is consolidated in the Office of Therapeutic Products, or OTP. The FDA has established the Cellular, Tissue and Gene Therapies Advisory Committee to advise CBER on its reviews. The NIH, including the Novel and Exceptional Technology and Research Advisory Committee, or the NExTRAC, also advises the FDA on gene therapy issues and other issues related to emerging biotechnologies. The FDA and the NIH have published guidance documents with respect to the development and submission of gene therapy protocols. ​ The FDA has issued various guidance documents regarding gene therapies. Although the FDA has indicated that these and other guidance documents it previously issued are not legally binding, the guidance documents provide the FDA’s current thinking on, among other things: the proper preclinical assessment of gene therapies; the chemistry, manufacturing and control information that should be included in an IND application; the proper design of tests to measure product potency in support of an IND or BLA application; and measures to observe for potential delayed 36 Table of Contents adverse effects in participants who have received investigational gene therapies with the duration of follow-up based on the potential for risk of such effects. For AAV vectors specifically, the FDA has typically recommended that sponsors continue to monitor participants for potential gene therapy-related adverse events for up to a five-year period. The FDA recommends that these long-term follow-up studies include, at a minimum, five years of annual physical examinations followed by annual queries, either in-person or by phone or written questionnaire, for the remaining observation period. Manufacturing and Other Regulatory Requirements Concurrently with clinical trials, sponsors usually complete additional animal safety studies, develop additional information about the chemistry and physical characteristics of the product candidate and finalize a process for manufacturing commercial quantities of the product candidate in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other criteria, the sponsor must develop methods for testing the identity, strength, quality, and purity of the finished product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life. Specifically, the FDA’s regulations require that pharmaceutical products be manufactured in specific approved facilities and in accordance with cGMPs. The cGMP regulations include requirements relating to organization of personnel, buildings and facilities, equipment, control of components and product containers and closures, production and process controls, packaging and labeling controls, holding and distribution, laboratory controls, records and reports and returned or salvaged products. Manufacturers and other entities involved in the manufacture and distribution of approved pharmaceuticals are required to register their establishments with the FDA and some state agencies and are subject to periodic unannounced inspections by the FDA for compliance with cGMPs and other requirements. The PREVENT Pandemics Act, which was enacted in December 2022, clarifies that foreign drug manufacturing establishments are subject to registration and listing requirements even if a drug or biologic undergoes further manufacture, preparation, propagation, compounding, or processing at a separate establishment outside of the United States prior to being imported or offered for import into the United States. Inspections must follow a “risk-based schedule” that may result in certain establishments being inspected more frequently. Manufacturers may also have to provide, on request, electronic or physical records regarding their establishments. Delaying, denying, limiting, or refusing inspection by the FDA may lead to a product being deemed to be adulterated. Changes to the manufacturing process, specifications or container closure system for an approved product are strictly regulated and often require prior FDA approval before being implemented. The FDA’s regulations also require, among other things, the investigation and correction of any deviations from cGMP and the imposition of reporting and documentation requirements upon the sponsor and any third-party manufacturers involved in producing the approved product. In May 2025, the FDA disclosed plans to expand its use of unannounced inspections of foreign manufacturing facilities that produce drugs and biologics distributed in the U.S. Subsequently, in August 2025, the FDA introduced a “PreCheck” program with the intention of supporting companies as they build new facilities in the U.S. The PreCheck program provides manufacturers with more frequent FDA communication at critical development stages, including facility design, construction, and pre-production. These FDA initiatives flow from an Executive Order issued by President Trump on May 5, 2025, calling for actions to reduce regulatory barriers to pharmaceutical manufacturing in the United States. Pediatric Studies Under the Pediatric Research Equity Act of 2003, or PREA, a BLA or supplement thereto must contain data that are adequate to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective, unless granted a deferral or waiver. The sponsor must submit an initial pediatric study plan within 60 days of an EOP2 meeting or as may be agreed between the sponsor and the FDA. Sponsors must also submit pediatric study plans prior to the assessment data. Those plans must contain an outline of the proposed pediatric study or studies the sponsor plans to conduct, including study objectives and design, any deferral or waiver requests, and other information required by regulation. The sponsor, the FDA, and the FDA’s internal review committee must then review the 37 Table of Contents information submitted, consult with each other, and agree upon a final plan. The FDA or the sponsor may request an amendment to the plan at any time. The FDA may, on its own initiative or at the request of the sponsor, grant deferrals for submission of some or all pediatric data until after approval of the product for use in adults, or full or partial waivers from the pediatric data requirements. A deferral may be granted for several reasons, including a finding that the product or therapeutic candidate is ready for approval for use in adults before pediatric trials are complete or that additional safety or effectiveness data needs to be collected before the pediatric trials begin. A waiver may be granted when the disease or condition does not occur in pediatrics. Unless otherwise required by regulation, the pediatric data requirements generally do not apply to products with orphan designation although FDA has taken steps to limit what it considers abuse of this statutory exemption in PREA by announcing that it does not intend to grant any additional orphan drug designations for rare pediatric subpopulations of what is otherwise a common disease. The FDA maintains a list of diseases that are exempt from PREA requirements due to low prevalence of disease in the pediatric population. In May 2023, the FDA issued new draft guidance that further describes the pediatric study requirements under PREA. Submission of a BLA to the FDA FDA approval is required before any new biologic product can be marketed in the United States. Thus, assuming successful completion of all required preclinical and human testing in accordance with all applicable regulatory requirements, detailed product information is submitted to the FDA in the form of a BLA. Under the PDUFA, each BLA must be accompanied by a significant user fee unless an exception or waiver applies, such as the first application filed by a small business or BLAs for product candidates designated as orphan drugs, unless the product candidate includes an indication that is not for a rare disease or condition. For federal fiscal year 2026, the application user fee is $4,682,003 for an application requiring clinical data, and the sponsor of a licensed BLA is subject to an annual program fee, which for fiscal year 2026 is $442,213. The FDA conducts a preliminary review of all applications within 60 days of receipt and must inform the sponsor at that time or before whether an application is sufficiently complete to permit substantive review. In pertinent part, FDA’s regulations state that an application “shall not be considered as filed until all pertinent information and data have been received” by the FDA. In the event the FDA determines that an application does not satisfy this standard, it will issue a Refuse to File, or RTF, determination to the sponsor. In this event, the BLA must be resubmitted. In October 2025, the FDA issued internal guidance clarifying that “materially incomplete or inadequately organized” applications that would not permit timely, efficient and complete review will be the subject of an RTF. The internal guidance also provides that the agency will issue an RTF for an application that relies on a single adequate and well-controlled investigation to support approval if prior communications with the FDA determined the need for more than one clinical study and any justification for a single investigation is inadequate. If the submission is accepted for filing, the FDA’s goal is to review the BLA, within ten months for a standard review, or, if the BLA relates to an unmet medical need in the treatment of a serious or life-threatening condition, perform a priority review, within six months. The review process may be extended by the FDA for three additional months to consider new information or in the case of a clarification provided by the sponsor to address an outstanding deficiency identified by the FDA following the original submission. Despite these review goals, it is not uncommon for FDA review of an application to extend beyond the PDUFA target action date. ​ The FDA seeks to meet these timelines for review of an application but its ability to do so may be affected by a variety of factors, including government budget and funding levels, the ability to hire and retain key personnel and statutory, regulatory and policy changes. Average review times at the agency have fluctuated in recent years as a result. For example, during the past decade, the U.S. government has shut down several times and certain regulatory agencies, including the FDA, have had to furlough critical employees and stop critical activities, including the review of both NDAs and BLAs when funding from PDUFA fee payments was exhausted. ​ The FDA may refer applications for novel biological products or biological products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and under what conditions. 38 Table of Contents The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions. During the biological product approval process, the FDA also will determine whether a REMS is necessary to assure the safe use of the biological product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS; the FDA will not approve the BLA without a REMS, if required. ​ Moreover, the FDA will review a sponsor’s financial relationship with the principal investigators who conducted the clinical trials in support of the BLA or NDA. Depending on the level of that compensation and any other financial interest a principal investigator may have in a sponsor, the sponsor may be required to report these relationships to the FDA. The FDA will then evaluate that financial relationship and determine whether it creates a conflict of interest or otherwise affects the interpretation of the trial, or the integrity of the data generated at the principal investigator’s clinical trial site. If so, the FDA may exclude data from the clinical trial site in connection with its determination of the approvability of the application for the investigational product. ​ In connection with its review of a BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, the FDA will typically inspect one or more clinical trial sites to assure that the clinical trials were conducted in compliance with IND study requirements and GCP requirements. With passage of FDORA, Congress clarified the FDA’s authority to conduct inspections by expressly permitting inspection of facilities involved in the preparation, conduct, or analysis of clinical and non-clinical studies submitted to the FDA as well as other persons holding study records or involved in the study process. To assure cGMP and GCP compliance, a sponsor must incur significant expenditure of time, money and effort in the areas of training, record keeping, production, and quality control. ​ The FDA’s Decision on a BLA ​ The FDA reviews an application to determine, among other things, whether the product is safe, pure, and potent. To reach this determination, the FDA must determine that the investigational product is effective and that its expected benefits outweigh its potential risks to patients. This “benefit-risk” assessment is informed by the extensive body of evidence about the product’s safety, purity and potency in the BLA. This assessment is also informed by other factors, including: the severity of the underlying condition and how well patients’ medical needs are addressed by currently available therapies; uncertainty about how the premarket clinical trial evidence will extrapolate to real-world use of the product in the post-market setting; and whether risk management tools are necessary to manage specific risks. ​ In February 2026, the Commissioner of FDA and the Director of Center for Biologics Evaluation and Research published an editorial in the New England Journal of Medicine in which they declared that, in most cases, the new default requirement for FDA approval of a new product will be one adequate and well-controlled pivotal clinical trial plus confirmatory evidence, rather than two pivotal clinical trials. In determining whether to rely on one trial, the FDA will focus on the single trial’s quality, including magnitude of effect, appropriateness of control arms, endpoint selection, statistical power, blinding, handling of missing data, biological plausibility and alignment with intermediate biomarkers. The FDA has long had authority to approve new products on the basis of one trial plus confirmatory evidence and, in recent years, the agency has exercised that authority with respect to certain types of products. The FDA now takes the position that this will be the new official default standard for most product candidates. At this point, it is unclear how this new policy will be implemented by the FDA and how, if at all, it will affect our clinical development programs. After evaluating the application and all related information, including the advisory committee recommendations, if any, and inspection reports of manufacturing facilities and clinical trial sites, the FDA will issue either a Complete Response Letter, or CRL, or an approval letter. A CRL indicates that the review cycle of the application is complete, and the application will not be approved in its present form. A CRL generally outlines the deficiencies in the submission and may require substantial additional testing or information in order for the FDA to reconsider the application. The CRL may require additional clinical or other data, additional pivotal Phase 3 clinical trial(s) and/or other significant and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. If a CRL is issued, the sponsor will have one year to respond to the deficiencies identified by the FDA, at which time the FDA can deem the application withdrawn or, in its discretion, grant the sponsor an additional six-month extension to respond. While CRLs were previously treated by the FDA as confidential and were only disclosed in action 39 Table of Contents packages for approved products, the FDA announced in September 2025 that it will now release CRLs promptly after they are issued to sponsors. Since that announcement, the FDA has posted a number of CRLs on its website. For those seeking to challenge the FDA’s CRL decision, the FDA has indicated that sponsors may request a formal hearing on the CRL, or they may file a request for reconsideration or a request for a formal dispute resolution. During the product approval process, the FDA also will determine whether a REMS is necessary to assure the safe use of the product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS; the FDA will not approve the BLA without a REMS, if required. An approval letter, on the other hand, authorizes commercial marketing of the product with specific prescribing information for specific indications. That is, the approval will be limited to the conditions of use (e.g., patient population, indication) described in the FDA-approved labeling. Further, depending on the specific risk(s) to be addressed, the FDA may require that contraindications, warnings or precautions be included in the product labeling, require that post-approval trials, including post-marketing studies or clinical trials, be conducted to further assess a product’s safety after approval, require testing and surveillance programs to monitor the product after commercialization or impose other conditions, including distribution and use restrictions or other risk management mechanisms under a REMS which can materially affect the potential market and profitability of the product. The FDA may prevent or limit further marketing of a product based on the results of post-marketing studies, clinical trials, or surveillance programs. After approval, some types of changes to the approved product, such as adding new indications, manufacturing changes and additional labeling claims, are subject to further testing requirements and FDA review and approval. Post-Approval Requirements Biologic products manufactured or distributed pursuant to regulatory approvals are subject to pervasive and continuing regulation by the regulatory authorities, including, among other things, requirements relating to formal commitments for post approval clinical trials and studies, manufacturing, recordkeeping, periodic reporting, product sampling and distribution, marketing, labeling, advertising and promotion and reporting of adverse experiences with the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior regulatory authority review and approval. ​ Manufacturers are subject to periodic unannounced inspections by regulatory authorities and country or state agencies for compliance with cGMP and other requirements. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior regulatory approval before being implemented. Regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirements upon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance. Further, although physicians may prescribe legally available products for unapproved uses or patient populations, which are commonly referred to as “off-label uses,” manufacturers may not market or promote such uses. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability. In September 2021, the FDA published final regulations which describe the types of evidence that the FDA will consider in determining the intended use of a biologic. If a company is found to have promoted off-label uses, it may become subject to administrative and judicial enforcement by the FDA, the Department of Justice, or the Office of the Inspector General of the HHS, as well as state authorities. It may be permissible, under very specific, narrow conditions, for a manufacturer to engage in nonpromotional, non-misleading communication regarding off-label information, such as distributing scientific or medical journal information. Moreover, with passage of the Pre-Approval Information Exchange Act, or PIE Act, in December 2022, sponsors of products that have not been approved may proactively communicate to payors certain information about products in development to help expedite patient access upon product approval. Previously, such communications were permitted under FDA guidance, but this legislation explicitly provides protection to sponsors who convey certain information about products in development to payors, including unapproved uses of approved products. 40 Table of Contents In addition, in January 2025, the FDA published final guidance outlining its policies governing the distribution of scientific information to healthcare providers about unapproved uses of approved products. The final guidance calls for such communications to be truthful, non-misleading and scientifically sound and to include all information necessary for healthcare providers to interpret the strengths and weaknesses and validity and utility of the information about the unapproved use of the approved product. If a company engages in such communications consistent with the guidance’s recommendations, the FDA indicated that it will not treat such communications as evidence of unlawful promotion of a new intended use for the approved product. On September 9, 2025, President Trump issued a Memorandum directing HHS to “ensure transparency and accuracy in direct-to-consumer prescription drug advertising, including by increasing the amount of information regarding any risks associated with the use of any such prescription drug required to be provided in prescription drug advertisements.” To that end, the FDA announced that it is initiating a rulemaking process “to eliminate the ‘adequate provision’ loophole that allows pharmaceutical advertisements to hide safety information by placing it in another format or location.” In this context, the FDA declared that it will no longer tolerate what it characterized as “deceptive practices” in prescription drug advertising and that the agency would “aggressively deploy” its available enforcement tools, with “heightened scrutiny” of fair balance and disclosures in social media promotions. The FDA also issued a generic “notice letter” directing companies to “remove any noncompliant advertising and bring all promotional communications into compliance.” Further, the distribution of prescription pharmaceutical products is subject to a variety of federal and state laws. The Prescription Drug Marketing Act, or PDMA, was the first federal law to set minimum standards for the registration and regulation of drug distributors by the states and to regulate the distribution of drug samples. Both the PDMA and state laws limit the distribution of prescription pharmaceutical product samples and impose requirements to ensure accountability in distribution. In November 2013, the federal Drug Supply Chain Security Act, or DSCSA, became effective in the United States, mandating an industry-wide, electronic, interoperable system to trace prescription drugs through the pharmaceutical distribution supply chain with a ten-year phase-in process. Manufacturers were required by November 2023 to have such systems and processes in place. So as not to disrupt supply chains, the FDA has granted certain exemptions from enhanced drug distribution security requirements for eligible trading partners for particular periods of time. For wholesale drug distributors, the final DSCSA deadline was August 27, 2025, marking the date for mandatory transition to a fully electronic, interoperable system for tracking prescription drugs at the package level throughout the United States. Expedited Review Programs The FDA is authorized to expedite the review of applications in several ways. None of these expedited programs, however, changes the standards for approval but each may help expedite the development or approval process governing product candidates. ● Fast Track Designation . Product candidates are eligible for Fast Track designation if they are intended to treat a serious or life-threatening condition and demonstrate the potential to address unmet medical needs for the condition. Fast Track designation applies to the combination of the product candidate and the specific indication for which it is being studied. In addition to other benefits, such as the ability to have greater interactions with the FDA, this designation enables a company to petition FDA to initiate review of sections of an NDA or a BLA application before the application is complete, a process known as rolling review. ​ ● Breakthrough therapy designation . To qualify for the breakthrough therapy program, product candidates must be intended to treat a serious or life-threatening disease or condition, and preliminary clinical evidence must indicate that such product candidates may demonstrate substantial improvement on one or more clinically significant endpoints over existing therapies. The FDA will seek to ensure the sponsor of a breakthrough therapy product candidate receives intensive guidance on an efficient development program, involvement of senior managers and experienced staff on a proactive, collaborative and cross-disciplinary review and rolling review. ​ 41 Table of Contents ● Priority review . A product candidate is eligible for priority review if it treats a serious condition and, if approved, it would be a significant improvement in the safety or effectiveness of the treatment, diagnosis or prevention compared to marketed products. Significant improvement may be illustrated by evidence of increased effectiveness in the treatment of a condition, elimination or substantial reduction of a treatment-limiting product reaction, documented enhancement of patient compliance that may lead to improvement in serious outcomes, and evidence of safety and effectiveness in a new subpopulation. FDA aims to complete its review of priority review applications within six months as opposed to ten months for standard review. ​ ● Regenerative Medicine Advanced Therapy (RMAT) designation . With the passage of the 21st Century Cures Act, or the Cures Act, in December 2016, Congress authorized the FDA to accelerate review and approval of products designated as regenerative advanced therapies. A product is eligible for this designation if it is a regenerative medicine therapy that is intended to treat, modify, reverse or cure a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the product candidate has the potential to address unmet medical needs for such disease or condition. The benefits of a regenerative advanced therapy designation include early interactions with the FDA to expedite development and review, benefits available to breakthrough therapies, potential eligibility for priority review and the potential for accelerated approval based on surrogate or intermediate endpoints. ​ ● Commissioner’s National Priority Voucher Program . On June 17, 2025, the FDA announced the creation of a new voucher program to expedite the development and approval of new drug products. Vouchers issued under the new program, which is known as the Commissioner’s National Priority Voucher, or CNPV, Program, may reportedly be redeemed by sponsors to shorten the review time of an NDA from approximately 10-12 months to 1-2 months. The FDA has indicated that the new CNPV process will convene experts from the FDA’s offices for a team-based review rather than using the standard review system of a drug application being sent to numerous FDA offices. Clinical information will be reviewed by a multidisciplinary team of physicians and scientists who will pre-review the submitted information and convene for a one-day meeting. Vouchers under this program will reportedly be given to companies aligned with U.S. national priorities. As with the FDA’s other programs for expediting review and approval of new drug products, there is no guarantee a product candidate submitted with a CNPV would result in approval of its marketing application or that such approval, if granted, would be on an expedited basis. ​ ● Rare Disease Evidence Principles . In September 2025, the FDA introduced a framework intended to streamline the approval of new therapies for ultrarare diseases. The Rare Disease Evidence Principles is intended to allow sponsors to rely on a single-arm trial in support of approval of drugs and biologics that treat rare diseases with very small patient populations and where the disease is linked to a known genetic defect and characterized by progressive functional deterioration leading to disability or death in a short period of time. The targeted diseases should also lack adequate alternative therapies. ​ Accelerated Approval ​ Biologic products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may receive accelerated approval. Accelerated approval means that a product candidate may be approved on the basis of adequate and well controlled clinical trials establishing that the product candidate has an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit, or on the basis of an effect on a clinical endpoint other than survival or irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity and prevalence of the condition and the availability or lack of alternative treatments. As a condition of approval, the FDA may require that a sponsor of a biologic product candidate receiving accelerated approval perform adequate and well controlled post-marketing studies or clinical trials. In addition, the FDA currently requires as a condition for accelerated approval pre-approval of all promotional materials. With the passage of FDORA, Congress modified certain provisions governing accelerated approval of drug and biologic products. Specifically, the new legislation authorized the FDA to require a sponsor to have its confirmatory clinical trial underway before accelerated approval is awarded and to submit progress reports on its post-approval studies to FDA every six months until the study is completed. Moreover, FDORA established expedited procedures authorizing 42 Table of Contents FDA to withdraw an accelerated approval if certain conditions are met, including where a required confirmatory study fails to verify and describe the predicted clinical benefit or where evidence demonstrates the product is not shown to be safe or effective under the conditions of use. The FDA may also use such procedures to withdraw an accelerated approval if a sponsor fails to conduct any required post-approval study of the product with due diligence, including with respect to “conditions specified by the Secretary.” The new procedures include the provision of due notice and an explanation for a proposed withdrawal, and opportunities for a meeting with the Commissioner or the Commissioner’s designee and a written appeal, among other things. In March 2023, the FDA issued draft guidance that outlines its current thinking and approach to accelerated approval. The agency indicated that the accelerated approval pathway is commonly used for approval of oncology drugs due to the serious and life-threatening nature of cancer. Although single-arm trials have been commonly used to support accelerated approval, a randomized controlled trial is the preferred approach as it provides a more robust efficacy and safety assessment and allows for direct comparisons to an available therapy. To that end, the FDA outlined considerations for designing, conducting, and analyzing data for trials intended to support accelerated approvals of oncology therapeutics. Subsequently, in December 2024 and January 2025, the FDA issued additional draft guidance relating to accelerated approval. This guidance describes FDA’s views on what it means to conduct a confirmatory trial with due diligence and how the agency plans to interpret whether such a study needs to be underway at the time of approval. While this guidance is currently only in draft form and will ultimately not be legally binding even when finalized, sponsors typically observe the FDA’s guidance closely to ensure that their investigational products qualify for accelerated approval. U.S. Orphan Drug Designation and Exclusivity A product may qualify for orphan drug designation, or ODD, under the Orphan Drug Act, if it is intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States and for which there is no reasonable expectation that the cost of developing and making a drug or biological product available in the United States for this type of disease or condition will be recovered from sales of the product as stipulated in the ODD. ODD must be requested before submitting a BLA. After the FDA grants ODD, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. ODD entitles a party to financial incentives such as opportunities for grant funding towards clinical study costs, tax advantages, and user-fee waivers. ODD does not convey any advantage in or shorten the duration of the regulatory review and approval process. If a product that has ODD receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications to market the same product for the same indication for seven years, except in limited circumstances, such as not being able to supply the product for patients or showing clinical superiority to the product with orphan exclusivity. Competitors, however, may receive approval of a different therapy for the indication for which the orphan product has exclusivity or obtain approval for the same product but for a different indication for which the orphan product has exclusivity. Orphan-drug exclusivity also could block the approval of one of our products for seven years if a competitor obtains approval of the same therapy in the same indication as defined by the FDA. The FDA and Congress may further reevaluate and revise the Orphan Drug Act and its regulations and policies. For example, in September 2021, the Court of Appeals for the Eleventh Circuit held that, for the purpose of determining the scope of orphan drug exclusivity, the term “same disease or condition” means the designated “rare disease or condition” and not the “indication or use” for which the product is approved. Subsequently, in another case, a federal district court in Washington, D.C. followed the reasoning of the Eleventh Circuit decision and that decision was appealed to the U.S. Court of Appeals for the D.C. Circuit. On February 3, 2026, the Consolidated Appropriations Act of 2026 was enacted into law. It overruled these court decisions and codified the FDA’s longstanding interpretation of the scope of orphan drug exclusivity to apply to “the same drug for the same approved use or indication within such designated rare disease or condition.” This change, which applies retroactively, expressly authorizes the FDA to approve multiple versions of the same orphan drug for different sub-indications and subpopulations, such as adult and pediatric patients or multiple variations of the same disease that are caused by different genetic variants. 43 Table of Contents Priority Review Vouchers A priority review voucher, or PRV, is a voucher that the FDA issues to a sponsor of a rare pediatric disease or tropical disease product application at the time of the marketing application approval. Vouchers are transferable to other sponsors that may apply it to their NDAs or BLAs. A PRV entitles the holder to designate a single human drug application submitted under Section 505(b)(1) of the FDCA or Section 351 of the PHSA as qualifying for a priority review. An FDA priority review may expedite the review process of a marketing application reducing the review time from ten months after formal acceptance of the file to six months after formal acceptance of the file. Applying the PRV to a marketing application does not ensure the FDA’s approval of the marketing application and all requirements supporting the safety and efficacy of the product must be met. Under the statutory sunset provisions for the Rare Pediatric Disease PRV Program, the FDA was authorized to award a PRV for an approved rare pediatric disease product application if the rare pediatric disease designation was granted by December 20, 2024, and the BLA or NDA for that product is approved before September 30, 2026. This program was not reauthorized by Congress in 2024, although there appears to be Congressional support for doing so. Biosimilars and Exclusivity When a biological product is licensed for marketing by FDA with approval of a BLA, the product may be entitled to certain types of market and data exclusivity barring FDA from approving competing products for certain periods of time. In March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively the ACA, was enacted in the United States and included the Biologics Price Competition and Innovation Act of 2009, or the BPCIA. The BPCIA amended the PHSA to create an abbreviated approval pathway for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. To date, the FDA has approved both biosimilar products and interchangeable biosimilar products. In December 2022, Congress clarified through FDORA that the FDA may approve multiple first interchangeable biosimilar biological products so long as the products are all approved on the first day on which such a product is approved as interchangeable with the reference product. A reference biologic is granted 12 years of exclusivity from the time of first licensure of the reference product. Approval of a 351(k) application may not be made effective until twelve years after the date of first licensure of the reference product, which under the statute excludes the date of licensure of supplements and certain other applications. Additionally, a 351(k) application for a biosimilar or interchangeable biological product cannot be submitted for review until four years after the date on which the reference product was first licensed under section 351(a) of the PHSA. Even if a product is considered to be a reference product eligible for exclusivity, however, another company could market a competing version of that product if the FDA approves a full BLA for such product containing the sponsor’s own preclinical data and data from adequate and well controlled clinical trials to demonstrate the safety, purity, and potency of their product. The BPCIA also includes provisions to protect reference products that have patent protection. The biosimilar product sponsor and reference product sponsor may exchange certain patent and product information for the purpose of determining whether there should be a legal patent challenge. Based on the outcome of negotiations surrounding the exchanged information, the reference product sponsor may bring a patent infringement suit and injunction proceedings against the biosimilar product sponsor. The biosimilar applicant may also be able to bring an action for declaratory judgment concerning the patent. The FDA maintains a publicly-available online database of licensed biological products, which is commonly referred to as the “Purple Book.” The Purple Book lists product names, dates of licensure, and applicable periods of exclusivity. Further, the reference product sponsor must provide patent information and patent expiry dates to FDA following the exchange of patent information between biosimilar and reference product sponsors. This information is then published in the Purple Book. 44 Table of Contents There have been recent government proposals to reduce the 12-year reference product exclusivity period, but none has been enacted to date. At the same time, since passage of the BPCIA, many states have passed laws or amendments to laws, which address pharmacy practices involving biosimilar products. Further, in October 2025, the FDA issued draft guidance which proposes to eliminate the need for sponsors of biosimilar products to conduct comparative human clinical efficacy studies, allowing them to rely instead on analytical testing to demonstrate product differences from a reference product. Pediatric Exclusivity Pediatric exclusivity is a type of non-patent marketing exclusivity in the United States and, if granted, provides for the attachment of an additional six months of exclusivity. For biologic products, the six-month period may be attached to any existing regulatory exclusivities but not to any patent terms. The conditions for pediatric exclusivity include the FDA’s determination that information relating to the use of a new product in the pediatric population may produce health benefits in that population, the FDA making a written request for pediatric clinical trials, and the sponsor agreeing to perform, and reporting on, the requested clinical trials within the statutory timeframe. This six-month exclusivity may be granted if an NDA sponsor submits pediatric data that fairly respond to a written request from the FDA for such data. The data does not need to show the product to be effective in the pediatric population studied; rather, if the clinical trial is deemed to fairly respond to the FDA’s request, the additional protection is granted. If reports of requested pediatric studies are submitted to and accepted by the FDA within the statutory time limits, whatever statutory or regulatory periods of exclusivity that cover the product are extended by six months. U.S. Patent Term Restoration Depending upon the timing, duration and specifics of the FDA approval of the use of our product candidates, some of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of a BLA plus the time between the submission date of a BLA and the approval of that application, less any time the sponsor failed to act with due diligence. Only one patent applicable to an approved biological product is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may intend to apply for restoration of patent term for one of our currently owned or licensed patents to add patent life beyond its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant BLA. Other Healthcare Laws Although we currently do not have any products on the market, we will be subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states in which we conduct our business, if and when our product candidates are approved by the FDA and subject to federal healthcare reimbursement. Such laws include, without limitation, state and federal anti-kickback, fraud and abuse, false claims, privacy and security and physician sunshine laws and regulations. In addition, the U.S. Foreign Corrupt Practices Act, or FCPA, to which we are subject, prohibits corporations and individuals from engaging in certain activities to obtain or retain business or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in an official capacity. On February 10, 2025, President Trump issued an Executive Order directing the Attorney General to review the guidelines and policies governing FCPA investigations and enforcement actions. Per the Executive Order, this review will result in new DOJ FCPA guidelines intended to enhance American economic competitiveness and to safeguard 45 Table of Contents national security interests. During the 180-day review period, any new FCPA investigations and enforcement actions are to be suspended absent authorization from the Attorney General, and all existing FCPA investigations and enforcement actions will be reviewed. Additionally, after the Attorney General issues revised guidelines, the Executive Order directs her to assess whether “remedial measures” related to past FCPA actions are warranted. The implications of this action are not clear. Healthcare Reform ​ A primary trend in the U.S. healthcare industry and elsewhere is cost containment. There have been a number of federal and state proposals during the last few years regarding the pricing of biologic products, limiting coverage and reimbursement for medical products and other changes to the healthcare system in the United States. In March 2010, the United States Congress enacted the ACA, which, among other things, includes changes to the coverage and payment for pharmaceutical products under government healthcare programs. The ACA is intended to broaden access to health insurance, reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add transparency requirements for the healthcare and health insurance industries, impose taxes and fees on the health industry and impose additional health policy reforms. Since enactment of the ACA, there have been, and continue to be, numerous legal challenges and Congressional actions to repeal and replace provisions of the law. Litigation and legislation over the ACA are likely to continue, with unpredictable and uncertain results. ​ In March 2010, the United States Congress enacted the ACA, which, among other things, includes changes to the coverage and payment for products under government healthcare programs. Other legislative changes have been proposed and adopted in the United States since the ACA was enacted. For example, in August 2011, the Budget Control Act of 2011, among other things, created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2012 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs. This includes aggregate reductions of Medicare payments to providers of up to 2% per fiscal year, which will remain in effect through 2031 pursuant to the Coronavirus Aid, Relief and Economic Security Act, or CARES Act. ​ The American Taxpayer Relief Act of 2012, which was enacted in January 2013, among other things, further reduced Medicare payments to several providers, including hospitals, imaging centers, and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. These laws may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices we may obtain for any of our product candidates for which we may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used. Indeed, under current legislation, the actual reductions in Medicare payments may vary up to 4%. ​ Since enactment of the ACA, there have been, and continue to be, numerous legal challenges and Congressional actions to repeal and replace provisions of the law. For example, with enactment of the Tax Cuts and Jobs Act of 2017, or the TCJA, which was signed by President Trump on December 22, 2017, Congress repealed the “individual mandate.” The repeal of this provision, which requires most Americans to carry a minimal level of health insurance, became effective in 2019. Further, on June 17, 2021, the United States Supreme Court dismissed a challenge to the ACA after finding that the plaintiffs do not have standing to challenge the constitutionality of the ACA. During the first Trump Administration, the Congress and administration sought to overturn the ACA and related measures. Shortly after taking office in January 2025, President Trump revoked numerous executive orders issued by President Biden, including at least two executive orders (e.g., EO 14009, Strengthening Medicaid and the Affordable Care Act, and EO 14070, Continuing to Strengthen Americans’ Access to Affordable, Quality Health Coverage) that were designed to further implement the ACA. Litigation and legislation over the ACA are likely to continue, with unpredictable and uncertain results. 46 Table of Contents Pharmaceutica l Price Reform The prices of prescription pharmaceuticals have also been the subject of considerable discussion in the United States. There have been United States congressional inquiries, as well as proposed and enacted state and federal legislation designed to, among other things, bring more transparency to pharmaceutical pricing, review the relationship between pricing and manufacturer patient programs, and reduce the costs of pharmaceuticals under Medicare and Medicaid. In addition, the HHS and the FDA published a final rule allowing states and other entities to develop a Section 804 Importation Program, or SIP, to import certain prescription drugs from Canada into the United States. That regulation was challenged in a lawsuit by the Pharmaceutical Research and Manufacturers of America, or PhRMA, but the case was dismissed by a federal district court in February 2023 after the court found that PhRMA did not have standing to sue HHS. Several states have passed laws allowing for the importation of products from Canada. On January 5, 2024, the FDA approved Florida’s plan for Canadian product importation. That state now has authority to import certain products from Canada for a period of two years once certain conditions are met. Florida will first need to submit a pre-import request for each product selected for importation, which must be approved by the FDA. The state will also need to relabel the products and perform quality testing of the products to meet FDA standards. On May 21, 2025, the FDA announced that it would offer individual states the opportunity to submit a draft proposal for pre-review and meet with the agency to obtain initial feedback from FDA prior to formally submitting their SIP proposals. The intent of these meetings is to assist states in developing their proposals by further clarifying requirements, enhancing the quality of proposals submitted to the FDA and ultimately shortening the review timeline. Further, on November 20, 2020, HHS finalized a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The final rule would also eliminate the current safe harbor for Medicare drug rebates and create new safe harbors for beneficiary point-of-sale discounts and pharmacy benefit manager service fees. The Inflation Reduction Act of 2022, or IRA, further delayed implementation of this rule to January 1, 2032. On August 16, 2022, the IRA was signed into law by President Biden. The new legislation has implications for Medicare Part D, which is a program available to individuals who are entitled to Medicare Part A or enrolled in Medicare Part B to give them the option of paying a monthly premium for outpatient prescription drug coverage. Among other things, the IRA requires manufacturers of certain drugs to engage in price negotiations with Medicare (beginning in 2026), with prices that can be negotiated subject to a cap; imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation (first due in 2023); and replaces the Part D coverage gap discount program with a new discounting program (beginning in 2025). The IRA permits the Secretary of the HHS to implement many of these provisions through guidance, as opposed to regulation, for the initial years. Specifically, with respect to price negotiations, Congress authorized Medicare to negotiate lower prices for certain costly single-source drug and biologic products that do not have competing generics or biosimilars and are reimbursed under Medicare Part B and Part D. CMS may negotiate prices for ten high-cost drugs paid for by Medicare Part D starting in 2026, followed by 15 Part D drugs in 2027, 15 Part B or Part D drugs in 2028, and 20 Part B or Part D drugs in 2029 and beyond. This provision applies to drug products that have been approved for at least nine years and biologics that have been licensed for 13 years. Drugs and biologics that have been approved for a single rare disease or condition were originally categorically excluded from price negotiation. With the passage of the One Big Beautiful Bill Act on July 3, 2025, which was signed into law on July 4, 2025, Congress extended this exemption to drugs and biologics with multiple orphan drug designations. Further, the legislation subjects drug manufacturers to civil monetary penalties and a potential excise tax for failing to comply with the legislation by offering a price that is not equal to or less than the negotiated “maximum fair price” under the law or for taking price increases that exceed inflation. In addition, the IRA established inflation rebate programs under Medicare Part B and Part D. These programs require manufacturers to pay rebates to Medicare if they raise their prices for certain Part B and Part D drugs faster than the rate of inflation. On December 9, 2024, with issuance of its 2025 Physician Fee Schedule final regulation, CMS finalized its rules governing the IRA inflation rebate programs. 47 Table of Contents The legislation also requires manufacturers to pay rebates for drugs in Medicare Part D whose price increases exceed inflation. The new law also caps Medicare out-of-pocket drug costs at an estimated $4,000 a year in 2024 and, thereafter beginning in 2025, at $2,000 a year. The first cycle of negotiations for the Medicare Drug Price Negotiation Program commenced in the summer of 2023. On August 15, 2024, the HHS published the results of the first Medicare drug price negotiations for ten selected drugs that treat a range of conditions, including diabetes, chronic kidney disease, and rheumatoid arthritis. The prices of these ten drugs became effective January 1, 2026. On January 17, 2025, CMS announced its selection of 15 additional drugs covered by Part D for the second cycle of negotiations. Thereafter, following the change in administrations, CMS issued a public statement on January 29, 2025, declaring that lowering the cost of prescription drugs is a top priority of the new administration and CMS is committed to considering opportunities to bring greater transparency in the negotiation program. The second cycle of negotiations with participating drug companies occurred during 2025, and any negotiated prices for this second set of drugs will be effective starting January 1, 2027. ​ On June 6, 2023, Merck & Co. filed a lawsuit against HHS and CMS asserting that, among other things, the IRA’s Drug Price Negotiation Program for Medicare constitutes an uncompensated taking in violation of the Fifth Amendment of the Constitution. Subsequently, a number of other parties, including the U.S. Chamber of Commerce, Bristol Myers Squibb Company, the Pharmaceutical Research and Manufacturers of America, Astellas, Novo Nordisk, Janssen Pharmaceuticals, Novartis, AstraZeneca and Boehringer Ingelheim, also filed lawsuits in various courts with similar constitutional claims against HHS and CMS. HHS has generally won the substantive disputes in these cases or succeeded in getting claims dismissed for lack of standing. Most of these cases are now on appeal. On October 30, 2024, the U.S. Court of Appeals for the Third Circuit heard oral arguments in three of these cases. In April 2025, the U.S. Court of Appeals for the Second Circuit and the U.S. Court of Appeals for the Third Circuit heard arguments in an additional three cases. On May 8, 2025, the U.S. Court of Appeals for the Third Circuit rejected AstraZeneca L.P.’s challenge to the Medicare price negotiation program, finding that the program did not violate the company’s due process rights under the Constitution since there is no protected property interest in selling goods to Medicare beneficiaries at a price higher than what the government is willing to pay in reimbursement. Litigation involving these and other provisions of the IRA will continue with unpredictable and uncertain results. ​ The Trump Administration has taken a number of actions to reduce the costs of pharmaceutical products. For example, on April 15, 2025, President Trump issued an Executive Order which directs HHS to take steps to reduce the prices of pharmaceutical products. Such measures include streamlining the state drug importation program and modifying provisions of the 340B program. Further, on May 12, 2025, President Trump issued an additional Executive Order calling on pharmaceutical manufacturers to voluntarily reduce the prices of medicines in the United States. The order provides that if such actions do not lower the costs of pharmaceuticals, the Secretary of HHS would pursue other actions, including proposing a rulemaking that imposes most-favored-nation, or MFN, pricing in the United States. Thereafter, on July 31, 2025, the President issued letters to 17 pharmaceutical companies reiterating the requirements of the May 12, 2025, Executive Order and demanding that such companies extend MFN pricing to Medicaid patients, guarantee MFN pricing for newly-launched drug products, return increased revenues abroad to patients in the United States and provide for direct purchasing at MFN pricing. Since that time, virtually all of these pharmaceutical companies have entered into agreements with the administration to provide for lower prices on certain pharmaceuticals. ​ At the state level, individual states are increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. In addition, regional health care authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products, and which suppliers will be included in their prescription product and other health care programs. These measures could reduce the ultimate demand for our products, once approved, or put pressure on our product pricing. We expect that additional state and federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, which could result in reduced demand for our product candidates or additional pricing pressures. This may be increasingly true with respect to products approved pursuant to the accelerated approval pathway. State Medicaid programs and other payers are developing strategies and implementing significant coverage barriers, or refusing to cover these products 48 Table of Contents outright, arguing that accelerated approval drugs have insufficient or limited evidence despite meeting the FDA’s standards for accelerated approval. ​ Additional Regulation ​ In addition to the foregoing, state and federal laws regarding environmental protection and hazardous substances, including the Occupational Safety and Health Act, the Resource Conservancy and Recovery Act and the Toxic Substances Control Act, affect our business. These and other laws govern our use, handling and disposal of various biological, chemical and radioactive substances used in, and wastes generated by, our operations. If our operations result in contamination of the environment or expose individuals to hazardous substances, we could be liable for damages and governmental fines. We believe that we are in material compliance with applicable environmental laws and that continued compliance therewith will not have a material adverse effect on our business. We cannot predict, however, how changes in these laws may affect our future operations. Government Regulation Outside of the United States ​ In addition to regulations in the United States, we will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical trials and any commercial sales and distribution of our products. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries. ​ Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application much like the IND prior to the commencement of human clinical trials in these countries. ​ If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution. ​ Our Corporate Information ​ We were incorporated under the laws of Delaware in June 2013. Our principal executive offices are located at 75 Hayden Avenue, Lexington, Massachusetts. We lease our office and laboratory space, which consist of approximately 26,148 square feet located in Cambridge, Massachusetts and 93,449 square feet located in Lexington, Massachusetts. Our lease in Cambridge expires in 2026 and our lease in Lexington expires in 2031. We have subleased our office and laboratory space in Cambridge to a third party. ​ Employees and Human Capital Resources ​ As of December 31, 2025, we employed 141 full-time employees in the United States, including 112 in research and development positions and 29 in general and administrative positions. Approximately 59 of our employees have either an MD or PhD degree. In connection with the restructuring executed in December 2025, 30 employees, including 24 in research and development positions and six in general and administrative positions, separated from employment in January 2026 or are scheduled to separate from employment with the Company in March 2026. We have never had a work stoppage, and none of our employees is represented by a labor organization or under any collective-bargaining arrangements. We consider our employee relations to be positive. ​ Our human capital strategy is designed to attract, develop, and retain the talent necessary to advance our mission and support long-term organizational performance. We remain committed to maintaining a high-performance culture grounded in our core values—Patients First, Better Together, Transformative Innovation, and Disciplined Execution. These values guide how we work, collaborate, and make decisions, and we believe they are integral to delivering on our scientific and operational goals. Our employees consistently demonstrate these values in action, and throughout the year we recognize individuals and teams who have exemplified them through impactful contributions, 49 Table of Contents cross-functional collaboration, and leadership behaviors that strengthen our organization. We view our values as a critical driver of performance, accountability, and employee engagement, and we continue to reinforce them across our hiring, development, and recognition programs. Retention is a key priority, and we remain focused on succession planning at all levels, up to and including the CEO. We regularly monitor employee engagement and turnover trends to inform targeted actions that strengthen our employee experience. We offer a robust and competitive total rewards package, including but not limited to competitive salaries, excellent health and welfare benefits, a 401(k) plan with strong company match, short-term and long-term incentives, lifestyle spending accounts, and flexible paid time off. Overall, we believe our human capital practices support a resilient, high-performing workforce aligned with our long-term business objectives. ​ Available Information ​ Our Internet address is http://www.voyagertherapeutics.com. We make available, free of charge, on or through our website our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, proxy statements and any amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities and Exchange Act as soon as reasonably practicable after such material is electronically filed with or furnished to the Securities and Exchange Commission, or the SEC. The information on our website is not part of this Annual Report on Form 10-K for the year ended December 31, 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 50 Table of Contents ITEM 1A.     RISK FACTOR S The following risk factors and other information in this Annual Report on Form 10-K, including our financial statements and related notes thereto, should be carefully considered. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us or that we presently deem less significant may also impair our business operations. Please see the discussion under the caption “Forward-Looking Statements” in this Annual Report on Form 10-K for a discussion of some of the forward-looking statements that are qualified by these risk factors. If any of the following risks occur, our business, financial condition, results of operations and future growth prospects could be materially and adversely affected. Risks Related to Our Financial Position and Need for Capital We have a history of incurring significant losses and anticipate that we will continue to incur losses for the foreseeable future and may never achieve or maintain consistent profitability. We are an early-stage biotechnology company and have not yet generated revenues from the sales of our product candidates. All of our product candidates are in the early stages of development. Investment in biotechnology companies is highly speculative because it entails substantial upfront capital expenditures and significant risk that any product candidates will fail to be safe and efficacious, obtain regulatory approval or become commercially viable. We have not yet demonstrated the ability to complete any clinical trials of our product candidates, obtain marketing approvals, manufacture a commercial-scale product or conduct sales and marketing activities necessary for successful commercialization. We continue to incur significant expenses related to research and development, and other operations in order to commercialize our product candidates. We have a history of incurring significant operating losses. We had a net loss of $119.7 million, net loss of $65.0 million, and net income of $132.3 million for the years ended December 31, 2025, 2024, and 2023, respectively. As of December 31, 2025, we had an accumulated deficit of $445.9 million. We historically have financed our operations primarily through private placements of our redeemable convertible preferred stock, public offerings and private placements of our common stock, and strategic collaborations, including our prior collaborations with Sanofi Genzyme Corporation, or Sanofi Genzyme, AbbVie Biotechnology Ltd and AbbVie Ireland Unlimited Company, and our ongoing collaborations with Neurocrine Biosciences, Inc., or Neurocrine, and Novartis Pharma AG, or Novartis; our option and license agreement, or the Alexion Agreement, with Alexion, AstraZeneca Rare Disease, or Alexion; and our option and license agreement, or the 2022 Novartis Option and License Agreement, with Novartis. We refer to our ongoing collaborations with Neurocrine collectively as the Neurocrine Collaborations. To date, we have devoted substantially all of our financial resources to building our gene therapy and non-viral therapeutics platforms, selecting product programs, conducting research and development, including preclinical and clinical development of our product candidates, building our intellectual property portfolio, building our team, and establishing strategic collaborations. We expect that it could be several years before we have a commercialized product, if ever. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. We also anticipate the cost of goods and services, and the levels of compensation paid to employees will increase due to inflationary conditions existing in the general economy. The net losses we incur may fluctuate significantly from quarter to quarter. ​ We anticipate that our expenses will increase substantially if, and as, we: ​ ● initiate and conduct clinical trials in connection with our tau silencing program, which we expect to initiate in the second half of 2026, and continue to conduct clinical trials in connection with our anti-tau antibody program; ● continue investing in our proprietary antibody program, non-viral therapeutics platform, gene therapy platforms and programs, and other research and development initiatives; 51 Table of Contents ● continue investing in NeuroShuttle, our proprietary non-viral delivery platform leveraging novel receptor-binding molecules to transport multiple modalities of neurotherapeutics across the blood-brain barrier ; ● continue investing in and supporting TRACER™ (Tropism Redirection of AAV by Cell-type-specific Expression of RNA), our proprietary discovery platform to facilitate the selection of adeno-associated virus, or AAV, capsids , which we refer to as TRACER Capsids, and our investment to discover TRACER Capsids with broad tropism in CNS and other tissues with cell-specific transduction properties for particular therapeutic applications; ● continue investing in our collaboration with Transition Bio, Inc., or Transition Bio, to advance small molecules targeting TDP-43 to treat amyotrophic lateral sclerosis, or ALS, and frontotemporal dementia with TDP-43 pathology; ● increase our investment in the discovery and development of additional modalities for receptor-mediated non-viral delivery of therapeutic payloads to the CNS, including but not limited to our alkaline phosphatase and other BBB-receptor; ● conduct joint research and development under our strategic collaborations for the research, development, and commercialization of certain of our pipeline programs, including our Friedreich’s ataxia program, or the FA Program, pursuant to our collaboration and license agreement with Neurocrine entered into in January 2019, or the 2019 Neurocrine Collaboration Agreement , our glucosylceramidase beta 1 , or GBA1, gene therapy program for PD and other GBA1-mediated diseases, or the GBA1 Program , pursuant to our collaboration and license agreement with Neurocrine entered into in January 2023, or the 2023 Neurocrine Collaboration Agreement , and our Huntington’s disease program, or the Novartis HD Program , pursuant to our license and collaboration agreement with Novartis entered into in December 2023, or the 2023 Novartis Collaboration Agreement; ● initiate additional preclinical studies and clinical trials for, and continue research and development of, our other programs; ● continue our process research and development activities, as well as establish our research-grade manufacturing capabilities; ● identify additional diseases for treatment with our AAV gene and non-viral therapies and BBB-crossing technologies and develop additional programs or product candidates; ● seek marketing and regulatory approvals for any of our product candidates that successfully complete clinical development; ● maintain, expand, protect and enforce our intellectual property portfolio; ● identify, acquire or in-license other product candidates and technologies; ● expand our operational, financial and management systems and personnel, including personnel to support our clinical development, manufacturing and commercialization efforts; ● increase our clinical trial insurance coverage as we expand our clinical trials and increase our product liability insurance once we engage in commercialization efforts; and ● continue to operate as a public company. 52 Table of Contents Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses. Our expenses will increase if: ​ ● we are required by the U.S. Food and Drug Administration, or the FDA, or the European Medicines Agency, or EMA, or other regulatory agencies to redesign or modify trials or studies or to perform trials or studies in addition to those currently expected; ● there are any delays in the receipt of regulatory clearance to begin our planned clinical programs; or ● there are any delays in site initiation, enrollment of patients in or completion of our clinical trials or the development of our product candidates. To become and remain profitable, we must develop and commercialize, alone or with our collaborators, product candidates with significant market potential, which will require us to be successful in a range of challenging activities. These activities include completing preclinical studies and clinical trials of our product candidates; obtaining marketing approval for these product candidates; contracting with third parties with expertise in current good manufacturing practices, or cGMPs, to manufacture our product candidates at clinical and commercial scale; marketing and selling those products that are approved; satisfying any post-marketing requirements and achieving an adequate level of market acceptance of and obtaining and maintaining adequate coverage and reimbursement from third-party payors for such products; and protecting our rights to our intellectual property portfolio. We may never succeed in any or all of these activities and, even if we do, we may never generate revenues that are significant or large enough to achieve profitability. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company also could cause our stockholders to lose all or part of their investment. ​ We may not be able to generate sufficient revenue from the commercialization of our product candidates and may never be consistently profitable. ​ Our ability to generate revenue and achieve profitability depends on our ability, alone or with our collaboration partners, to successfully complete the development of, and obtain the regulatory approvals necessary to commercialize, our current and future product candidates. All of our product candidates are in the early stages of development. We do not anticipate generating revenues from product sales for at least the next several years, and we may never succeed in doing so. Our ability to generate future revenues from product sales depends heavily on our and our collaborators’ and licensors’ success in: ● completing preclinical and clinical development of our product candidates or product candidates incorporating our licensed capsids or other technologies and identifying new product candidates; ● seeking and obtaining regulatory and marketing approvals for product candidates for which we or they complete clinical development; ● launching and commercializing product candidates for which we or they obtain regulatory and marketing approval by establishing a sales, marketing and distribution infrastructure or, alternatively, collaborating with a commercialization partner; ● obtaining and maintaining adequate coverage and reimbursement by government and third-party payors for our product candidates if and when approved; ● maintaining and enhancing a sustainable, scalable, reproducible and transferable manufacturing process for our vectors and product candidates; 53 Table of Contents ● establishing and maintaining supply and manufacturing relationships with third parties that have the financial, operating and technical capabilities to provide adequate products and services, in both amount and quality, to support clinical development and the market demand for our or their product candidates, if and when approved; ● obtaining an adequate level of market acceptance of our or their product candidates as viable treatment options; ● addressing any competing technological and market developments; ● implementing additional internal systems and infrastructure, as needed; ● negotiating favorable terms in any collaboration, option, licensing, or other arrangements into which we may enter and performing our obligations in such collaborations; ● obtaining, maintaining, protecting, enforcing and expanding our portfolio of intellectual property rights, including patents, trade secrets and know-how; ● avoiding and defending against third-party claims of interference or infringement; and ● attracting, hiring and ret aining qualified personnel. Even if one or more of the product candidates that we develop is approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product candidate. Our expenses could increase beyond expectations if we are required by the FDA, EMA, or other regulatory authorities to redesign or modify preclinical studies or clinical trials or to perform preclinical studies or clinical trials in addition to those that we currently anticipate. Even if we are able to generate revenues from the sale of any approved products, we may not become profitable and may need to obtain additional funding to continue operations and may we decide to discontinue commercial availability and/or voluntarily request the withdrawal of the new drug application, or NDA, for any of our products, which may raise additional potential risks and uncertainties. Any issues or hurdles related to our commercialization efforts may materially adversely affect our business, results of operations, financial condition and prospects and could lead us to make significant further changes to the scope and nature of our efforts. ​ We will need to raise additional funding, which may not be available on acceptable terms, or at all. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate certain of our product development efforts or other operations. ​ We expect our expenses to increase over time in connection with our ongoing and planned activities, particularly as we continue the research and development of, continue or initiate clinical trials of, and seek marketing approval for, our product candidates. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant expenses related to product sales, medical affairs, marketing, manufacturing and distribution. We also continue to incur costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital or enter into business development transactions when needed or on acceptable terms, we could be forced to delay, reduce or eliminate certain of our research and development programs or any future commercialization efforts. ​ Our operations have consumed significant amounts of cash since inception. As of December 31, 2025, our cash, cash equivalents, and marketable securities were $201.7 million. Based upon our current operating plan, we expect that our existing cash, cash equivalents, and marketable securities as of December 31, 2025, along with amounts expected to be received as reimbursement for development costs under our collaboration and license agreements with Neurocrine and Novartis, and interest income, to be sufficient to meet our planned operating expenses and capital expenditure requirements into 2028. We have based this estimate on assumptions that may prove to be wrong. 54 Table of Contents Our future capital requirements will depend on many factors, including: ● the scope, progress, results, and costs of product discovery, preclinical studies and clinical trials for our product candidates, including our ongoing Phase 1 clinical trial to evaluate VY7523 and our planned Phase 1 clinical trial to evaluate VY1706; ● the scope, progress, results, costs, prioritization, and number of our research and development programs; ● the progress and status of our strategic collaborations and option and license agreements and any similar arrangements we may enter into in the future, including any research and development costs for which we are responsible, future additional obligations that we may be committed to in connection with these agreements, including, for example, if we elect to exercise our rights for any of the three programs for which we retain opt-in rights, and our receipt of any expense reimbursements, future milestone payments and royalties from our collaboration partners or licensors; ● the extent to which we are obligated to reimburse preclinical development and clinical trial costs, or the achievement of milestones or occurrence of other developments that trigger milestone and royalty payments, under any collaboration or license agreements to which we might become a party, such as the license agreement we entered into with Touchlight IP Limited , or Touchlight, in November 2022 , which we refer to as the Touchlight License Agreement, and the research collaboration, option and license agreement we entered into with Transition Bio, Inc., or Transition Bio, in June 2025; ● the costs, timing and outcome of regulatory review of our product candidates; ● our ability to establish and maintain collaboration, distribution, or other marketing arrangements for our product candidates on favorable terms, if at all; ● the costs and timing of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims; ● the extent to which we acquire or in-license other product candidates and technologies, including any intellectual property associated with such candidates or technologies, acquire or invest in other businesses, or out-license our product candidates, capsids or other technologies; ● the costs of advancing our manufacturing capabilities and securing manufacturing arrangements for pre-commercial and commercial production; ● the level of product sales by us or our collaborators from any product candidates for which we obtain marketing approval in the future; ● the costs of operating as a public company and maintaining adequate product, clinical trial, and directors’ and officers’ liability insurance coverage; and ● the costs of establishing or contracting for sales, manufacturing, marketing, distribution, and other commercialization capabilities if we obtain regulatory approvals to market our product candidates . Identifying potential product candidates and conducting preclinical studies and clinical trials is a time-consuming, expensive, and uncertain process that takes years to complete. We may never generate the necessary data or results required to maintain the financial support of our collaborators or obtain marketing approval and achieve product sales. In the event we are unable to achieve milestones necessary to demonstrate progress on those programs, a current or future collaboration partner or licensor may be unwilling to fund these programs at the desired levels, or at all, which could require us to fund these programs to a greater extent than we have expected, to decline to pursue certain program objectives or to discontinue one or more of the programs. Our ability to develop a product candidate for any of our lead gene therapy or other biological therapy programs may take longer than we anticipate, or may not happen at all, and 55 Table of Contents could require funding at a level higher than we expect. In addition, our product candidates, if approved, may not achieve commercial success. Our product revenues, if any, and any commercial milestone payments or royalty payments under our collaboration or option and license agreements, will be derived from sales of products that may not be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing and business development transactions to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all. ​ Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to our technologies or product candidates. ​ Until such time, if ever, as we can generate product revenues sufficient to achieve consistent profitability, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, and option and license arrangements. We do not have any committed external source of funds other than the amounts we are entitled to receive from our collaboration partners, Neurocrine and Novartis, and licensees for the reimbursement of certain research and development expenses, potential option exercises, the achievement of specified regulatory and commercial milestones, and royalty payments under the 2019 Neurocrine Collaboration Agreement, the 2023 Neurocrine Collaboration Agreement, and the 2023 Novartis Collaboration Agreement and the amounts we are entitled to receive from our licensees Alexion and Novartis for the achievement of specified development, regulatory, and commercialization milestones and royalty payments under the applicable option and license agreements. To the extent that we raise additional capital through the sale of equity or equity-linked securities, including convertible debt, our stockholders’ ownership interests will be diluted. For example, on November 10, 2025, we entered into a sales agreement with respect to an “at the market offering” program pursuant to which we may offer and sell shares of our common stock having an aggregate offering price of up to $100.0 million, from time to time through TD Securities (USA) LLC. Any significant sales of shares of our common stock pursuant to the sales agreement would result in dilution to our current stockholders. The amount of stockholder dilution through the sale of equity or equity-linked securities will be affected by the size of each securities offering and the offering price for the securities sold. The offering price will likely reflect the prevailing market price for our securities, with dilution increasing as the prevailing market price for our securities decreases. The terms of these securities may include liquidation or other preferences that adversely affect our existing stockholders’ rights as holders of our common stock. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, obtaining additional capital, acquiring or divesting businesses, making capital expenditures or declaring dividends. In addition, we may seek additional capital due to favorable market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. Our issuance of additional securities, whether equity or debt, or the possibility of such issuance, may cause the market price of our common stock to decline. Further, our existing stockholders may not agree with the terms of such financings. ​ If we raise additional funds through collaborations, strategic alliances, or option and license arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market products or product candidates that we would otherwise prefer to develop and market ourselves. Such collaborations, alliances, or option and license arrangements could therefore cause the market price of common stock to decline. The early stage of our development efforts may make it difficult for our stockholders to evaluate the success of our business to date and to assess our future viability. Our operating history to date has been limited to building our team, business planning, raising capital, establishing our intellectual property portfolio, determining which neurological diseases to pursue, advancing our product candidates, including delivery and manufacturing and conducting preclinical studies and early-phase clinical trials. Consequently, any predictions about our future success or viability may not be as accurate as they could be if we had an operating history that included the late stage of clinical development, completion of clinical development, or commercialization of one or more product candidates. VY7523, our anti-tau antibody candidate, is in early-stage clinical 56 Table of Contents trials, and all of our other active product candidates are currently in preclinical development, including VY1706, our tau silencing program. In addition, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors such as the regulatory setbacks that previously occurred in prior clinical programs we have conducted, such as those put on hold by the FDA, and the terminations, in part, of the 2019 Neurocrine Collaboration Agreement and the 2022 Novartis Option and License Agreement to date. These and other events that are part of our operating history may impact our ability to operate our business and to raise capital. All of our product candidates are in the early stages of development. To achieve our current goals, we will need to transition in the future from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in such a transition. We expect our financial condition and operating results to continue to fluctuate significantly from quarter-to-quarter and year-to-year due to a variety of factors, many of which are beyond our control as we advance more of our programs into the clinical stage. Accordingly, our stockholders should not rely upon the results of any quarterly or annual periods as indications of future operating performance. Risks Related to the Development and Regulatory Approval of Our Product Candidates Our AAV gene therapy, non-viral therapeutic, and other product candidates are based on proprietary technologies and, in several disease areas, unvalidated treatment approaches, which make it difficult and potentially infeasible to predict the duration and cost of development of, and subsequently obtaining regulatory approval for, our product candidates . Our future success depends on our successful development of AAV gene therapy and other biological therapy product candidates, including our anti-tau antibody candidate and non-viral therapeutic product candidates. VY7523, our anti-tau antibody candidate, is in early-stage clinical trials. Each of the other product candidates we are advancing, either alone or together with our strategic collaborators, is currently in preclinical development. We cannot accurately predict when or if any of our product candidates will prove effective or safe in humans or whether these product candidates will receive marketing approval. Additionally, there can be no assurance that we will not experience problems or delays in the preclinical testing or development of our product candidates and that such problems or delays will not cause unanticipated costs, or that any such problems or delays can be solved in a timely or profitable basis, if at all. For example, we are no longer advancing VY9323, formerly the lead development candidate for our superoxide dismutase 1, or SOD1, silencing gene therapy program for ALS, as a development candidate based on three-month data from a non-human primate good laboratory practice, or GLP, toxicology study suggesting that a different payload would be necessary to achieve the desired product profile for the program. We also may experience unanticipated problems or delays in expanding our manufacturing capacity or outsourcing manufacturing activities to contract manufacturers. The clinical trial requirements of the FDA, the EMA and other regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of the product candidate. The regulatory approval process for novel product candidates such as gene therapies can be more expensive and take longer than for other better known or more extensively studied product candidates. Until August 2017, the FDA had never approved an AAV gene therapy product. Since that time, it has approved a limited number of gene therapy products. In Europe, a similarly limited number of AAV gene therapy products have been granted marketing authorization. It is difficult to determine how long it will take or how much it will cost to obtain regulatory approvals for our product candidates in either the United States or the European Union or how long it will take to commercialize our product candidates. The few regulatory approvals of gene therapies to date may not be indicative of what the FDA, EMA, or other regulatory authorities may require for approval or whether different or additional preclinical studies or clinical trials may be required to support regulatory approval in a particular jurisdiction. Delay or failure to obtain, or unexpected costs in obtaining, the regulatory approval necessary to bring a potential product candidate to market could 57 Table of Contents decrease our ability to generate sufficient product revenue, and our business, financial condition, results of operations and prospects may be harmed. Regulatory requirements governing gene therapy , non-viral therapeutic , and other products have changed frequently and may continue to change in the future. Such requirements may lengthen the regulatory review process, require us to modify current studies or perform additional studies, or increase our development costs, which in turn may force us to delay, limit, or terminate certain of our programs. The Center for Biologics Evaluation and Research, or CBER, of the FDA regulates biological products, for human use. The Office of Tissues and Advanced Therapies, or OTAT, formerly known as the Office of Cellular, Tissue and Gene Therapies, within CBER reviews gene therapy and related products and has established the Cellular, Tissue and Gene Therapies Advisory Committee to advise CBER in its review. U.S. regulations require each clinical trial site’s institutional review board, or IRB, to review proposed clinical trials to assess the safety of the trial. If the protocol for such a trial was amended, it would need to be re-reviewed by the respective institutional IRBs of each institution. Any delay in or failure to obtain institutional IRB approval for any protocol or protocol amendment could delay, interrupt, or limit the conduct of the clinical trial at one or more participating clinical trial sites. Adverse or unforeseen developments in clinical trials of proprietary antibody and gene therapy products conducted by us or others may cause the FDA or other oversight bodies to change the requirements for approval of any of our product candidates. Similarly, EMA and local health authorities of individual countries within the European Union may issue new guidelines concerning the clinical development and marketing authorization for gene therapy medicinal products and require that we comply with these new guidelines. The EMA and agencies at both the federal and state level in the United States have expressed an interest in further regulating new biotechnologies, including gene therapy. In addition, gene therapy products are considered genetically-modified organism, or GMO, products and are regulated as such in each country. Designation of the type of GMO product and subsequent handling and disposal requirements can vary across countries and is variable throughout the European Union. Addressing each specific country requirement and obtaining approval to commence a clinical trial in these countries could result in delays in starting, conducting, or completing a clinical trial. Similar issues could be faced in other regions of the world. These regulatory review committees and advisory groups and the new guidelines they promulgate may lengthen the regulatory review process, require us to perform additional studies, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval and commercialization of these product candidates or lead to significant post-approval limitations or restrictions. As we advance our product candidates, we will be required to consult with these regulatory and advisory groups and comply with applicable guidelines. Any inability to receive timely, actionable feedback from regulatory authorities could also delay or otherwise hinder our development efforts. These and other regulatory delays may require us to incur additional clinical development costs, slow down our product candidate development and approval process and delay or potentially jeopardize our ability to commence product sales and generate revenue from our product candidates. We plan to continue to seek and incorporate FDA guidance in our ongoing development plans for each of our potential clinical candidates. If we fail to consult or solicit guidance from regulators or are unable to obtain sufficiently frequent or detailed guidance from regulators, we may be required to delay or discontinue development of certain of our product candidates. These additional processes may result in a review and approval process that is longer than we otherwise would have expected. Delays as a result of increased or lengthier regulatory approval process and further restrictions on development of our product candidates can be costly and could negatively impact our or our collaborators ’ ability to complete clinical trials and commercialize our current and future product candidates in a timely manner, if at all. 58 Table of Contents Results from preclinical studies and early-stage clinical trials may not be indicative of efficacy in late-stage clinical trials. ​ All of our product candidates are in early stages of development, and the risk of failure is high. Clinical testing is expensive, is difficult to design and implement, can take many years to complete and is uncertain as to outcome. A failure of one or more clinical trials can occur at any stage of testing. Our product candidates may fail to show the desired safety and efficacy in preclinical testing or clinical development despite demonstrating promising results in earlier preclinical studies or clinical trials. In addition, the outcome of preclinical testing and early clinical trials may not be predictive of the success of later stage clinical trials. For example, despite data we believed was promising from the earlier PD-1101 Phase 1b clinical trial and from the separate PD-1102 Phase 1 clinical trial evaluating the delivery of VY-AADC (NBIb-1817), we and our strategic collaborator Neurocrine did not receive favorable data from, and were ultimately unable to complete, the RESTORE-1 Phase 2 clinical trial evaluating VY-AADC (NBIb-1817) for the treatment of PD. ​ In addition, one of our competitors, Janssen Pharmaceuticals, Inc., a subsidiary of Johnson & Johnson, in 2025, discontinued their Phase 2 clinical study of posdinemab, an anti-tau antibody being investigated to treat early Alzheimer’s disease, following a scheduled review of clinical findings that determined posdinemab did not achieve statistical significance in slowing clinical decline, despite the results observed in earlier preclinical studies. ​ Similarly, interim results generated from clinical trials do not necessarily predict final results, and results from one completed clinical trial may not be replicated in a subsequent clinical trial with a similar study design. Some of our clinical trials were conducted with small patient populations and were not blinded or placebo-controlled, making it difficult to predict whether the favorable results that we observed in such trials will be sustained or repeated in larger and more advanced clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products. ​ A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials even after achieving promising results in early-stage clinical trials. If a larger population of patients does not experience positive results, if these results are not reproducible, or if our products show diminishing activity over time, our products may not receive approval from the EMA or the FDA. Data obtained from preclinical and clinical activities are subject to varying interpretations, which may delay, limit or prevent regulatory approval. In addition, we may encounter regulatory delays or rejections as a result of many factors, including changes in regulatory policy during the period of product development. Failure to confirm favorable results from earlier trials by demonstrating the safety and effectiveness of our products in late-stage clinical trials with larger patient populations could harm our business and we may never succeed in commercialization or generating product revenue. ​ We have conducted, and may in the future conduct, clinical trials for product candidates at sites outside the United States, and the FDA may not accept data from trials conducted in such locations. ​ We have conducted, and may in the future choose to conduct, one or more of our clinical trials outside the United States. ​ Although the FDA may accept data from clinical trials conducted outside the United States, acceptance of these data is subject to conditions imposed by the FDA. In cases where data from foreign clinical trials are intended to serve as the sole basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. ​ In addition, even where the foreign trial data are not intended to serve as the sole basis for approval, the FDA will not accept the data as support for an application for marketing approval unless the trial satisfies certain conditions. For example, the clinical trial must be well-designed and conducted and performed by qualified investigators in 59 Table of Contents accordance with ethical principles. The trial population must also adequately represent the U.S. population, and the data must be applicable to the U.S. population and U.S. medical practice in ways that the FDA deems clinically meaningful. In addition, while these clinical trials are subject to the applicable local laws, FDA acceptance of the data will depend on its determination that the trials also complied with all applicable U.S. laws and regulations. If the FDA does not accept the data from any trial we conduct outside the United States, it would likely result in the need for additional trials, which would be costly and time-consuming and would delay or permanently halt our development of the applicable product candidates. Even if the FDA accepted such data, it could require us to modify our planned clinical trials to receive clearance to initiate such trials in the United States or to continue such trials once initiated. ​ Other risks inherent in conducting international clinical trials or using international trial sites include: ● foreign regulatory requirements, differences in healthcare services, and differences in cultural customs that could restrict or limit our ability to conduct our clinical trials; ● the administrative burden of complying with a variety of foreign laws, medical standards and regulatory requirements, including the regulation of pharmaceutical and biotechnology products and treatment; ● the failure of enrolled patients to adhere to clinical protocols or inadequate collection and assessment of clinical data as a result of differences in healthcare services or cultural customs; ● foreign exchange fluctuations; ● diminished or loss of protection of intellectual property in the relevant jurisdiction; and ● political, economic, environmental, and health risks relevant to specific foreign countries, including risks related to natural disasters or disease outbreaks. We are early in our development efforts. VY7523, our anti-tau antibody candidate, is in early-stage clinical trials, and all of our other active product candidates, including VY1706, are currently in preclinical development. We or our collaborators may encounter substantial delays or difficulties in the commencement, enrollment or completion of preclinical studies or clinical trials, or we or our collaborators may fail to demonstrate safety and efficacy sufficient to support further development or to satisfy the applicable regulatory authorities, any of which could prevent us or our collaborators from further developing or commercializing current and future product candidates on a timely basis, if at all. Our future business prospects depend heavily on our ability, alone or through our collaborations, to successfully develop, gain regulatory approval of, and commercialize our current and future product candidates. Drug development and obtaining regulatory approval for a product involve a long, expensive and uncertain process, involving a high degree of risk. We are early in our development efforts. VY7523 is currently in early-stage clinical trials, and all of our other active product candidates (including VY1706) are currently in preclinical development. Before obtaining marketing approval from regulatory authorities for the sale of our current and future product candidates, we must conduct extensive clinical trials to demonstrate the safety and efficacy of the product candidates. We or our collaborators, as applicable, may not be able to demonstrate the safety and efficacy of any of our current product candidates or any future product candidate at each stage of clinical development or we may encounter other issues with any clinical trials or non-clinical studies required for regulatory submissions. Some or all of our or our collaborators’ clinical trials may fail to meet their primary or key secondary endpoints, raise safety issues or generate mixed results. ​ To conduct clinical trials, we must first complete preclinical testing and studies to support IND applications or similar applications in other jurisdictions. We cannot be certain of the timely completion or successful outcome of our preclinical testing and studies. Our ability to complete our preclinical testing and studies is contingent on, among other things, our ability to source animals and other supplies required for the conduct of such testing and studies. If we are unable to obtain such supplies, we may be unable to complete such preclinical testing and studies in a timely manner, or at all. For example, some of our IND-enabling toxicology, capsid discovery, and other studies require certain NHPs that are customarily imported from outside the United States. Our inability to obtain access to a sufficient supply of these 60 Table of Contents NHPs in a timely manner, or at all, may impair or delay our ability to complete preclinical studies to support capsid discovery efforts or IND applications or similar applications in other jurisdictions. We have previously encountered, and may encounter in the future, delays in obtaining a sufficient supply of such NHPs due to governmental or regulatory actions that result in importation restrictions in the United States or exportation restrictions in the country of origin. At times when the NHP supply in the United States has been constrained, we have conducted NHP studies at contract research facilities outside of the United States. When utilizing such facilities, we are required to observe export control regulations for the shipment of product candidates and their component materials and import control regulations for the shipment of samples to us for evaluation and storage. We may be required to incur delays or expenses in order to conduct our NHP studies in compliance with these regulations, and we may be subject to additional penalties, delays, or expenses if we fail to achieve compliance. ​ Additionally, we cannot predict if the FDA or similar regulatory authorities outside the United States will accept our planned clinical programs or if the outcome of our preclinical testing and studies will ultimately support the further development of our preclinical and clinical programs. In connection with our earlier VY-HTT01 Program for the treatment of Huntington’s disease, for example, we were unable to successfully predict what the FDA would require and were unable to obtain a second pre-IND meeting with the FDA to discuss the product candidate’s regulatory pathway with the FDA. As a result, in October 2020, the FDA notified us that the IND application for the planned Phase 1 and Phase 2 clinical trial to evaluate VY-HTT01 had been put on clinical hold. ​ In addition, the FDA’s and other regulatory authorities’ policies with respect to clinical trials may change and additional government regulations may be enacted. For example, in December 2022, with the passage of Food and Drug Omnibus Reform Act, known was FDORA, Congress required sponsors to develop and submit a diversity action plan, or DAP, for each Phase 3 clinical trial or any other “pivotal study” of a new drug or biological product. These plans are meant to encourage the enrollment of more diverse patient populations in late-stage clinical trials of FDA-regulated products. Specifically, action plans must include the sponsor’s goals for enrollment, the underlying rationale for those goals, and an explanation of how the sponsor intends to meet them. In addition to these requirements, the legislation directs the FDA to issue new guidance on DAPs. In June 2024, as mandated by FDORA, the FDA issued draft guidance outlining the general requirements for DAPs. Unlike most guidance documents issued by the FDA, the DAP guidance when finalized will have the force of law because FDORA specifically dictates that the form and manner for submission of DAPs are specified in FDA guidance. On January 27, 2025, in response to an Executive Order issued by President Trump on January 21, 2025, on Diversity, Equity and Inclusion programs, the FDA removed this draft guidance from its website. Thereafter, following litigation, the FDA was directed by a federal district court to restore the draft guidance to the FDA website. When the FDA did so, it stated that “information on this page may be modified and/or removed in the future subject to the terms of the court’s order and implemented consistent with applicable law.” Accordingly, in light of these ongoing actions, there is considerable uncertainty surrounding the draft DAP guidance and how the FDA will consider diversity action plans in connection with its review of BLAs. Similarly, the regulatory landscape related to clinical trials in the European Union, or EU, recently evolved. The EU Clinical Trials Regulation, or CTR, which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. While the Clinical Trials Directive required a separate clinical trial application, or CTA, to be submitted in each member state, to both the competent national health authority and an independent ethics committee, the CTR introduces a centralized process and only requires the submission of a single application to all member states concerned. The CTR allows sponsors to make a single submission to both the competent authority and an ethics committee in each member state, leading to a single decision per member state. The assessment procedure of the CTA has been harmonized as well, including a joint assessment by all member states concerned, and a separate assessment by each member state with respect to specific requirements related to its own territory, including ethics rules. Each member state’s decision is communicated to the sponsor via the centralized EU portal. Once the CTA is approved, clinical study development may proceed. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials, our development plans may be impacted. ​ We cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, if at all. A clinical trial failure can occur at any stage of testing. Similarly, there may be delays or difficulties in our initiation of future clinical trials. For example, we no longer expect to file an IND or Canadian clinical trial application for VY9323, formerly the lead development candidate for our SOD1 silencing program for ALS, based on three-month data from a 61 Table of Contents non-human primate GLP toxicology study suggesting that a different payload would be necessary to achieve the desired product profile for the program. ​ Identifying and qualifying patients to participate in clinical trials of our product candidates is critical to our success. We may not be able to identify, recruit and enroll a sufficient number of patients, or those with required or desired characteristics, to complete our clinical trials in a timely manner, or at all, pursuant to the requirements of the FDA, EMA, or other regulatory authorities. Patient enrollment and trial completion are affected by many factors including: ​ ● perceived risks and benefits of proprietary antibody , AAV gene therapy , and non-viral therapeutic approaches for the treatment of neurological and other diseases; ● formulation changes to our product candidates, which may require us to conduct additional clinical studies to bridge our modified product candidates to earlier versions; ● size of the patient population and process for identifying patients; ● design of the trial protocol; ● eligibility and exclusion criteria; ● patients with preexisting antibodies to the gene therapy vector that preclude their participation in the trial; ● perceived risks and benefits of the product candidate under study; ● availability of competing therapies and clinical trials; ● severity of the disease under investigation; ● availability of genetic testing for potential patients; ● proximity and availability of clinical trial sites for prospective patients; ● lack of adequate compensation of patients; ● ability to obtain and maintain patient consent; ● risk that enrolled patients will drop out before completion of the trial; ● our ability to locate appropriately trained physicians to conduct such clinical trials, particularly for clinical trials requiring lengthy and highly complex surgical protocols, the performance of which may only be possible at major academic medical centers or specialized surgical centers; ● willingness of patients to participate in a placebo-controlled trial or a trial requiring an in-patient stay or frequent site visits; ● patient referral practices of physicians; and ● ability to monitor patients adequately during and after treatment. 62 Table of Contents There is also the potential for slower than expected clinical site initiation, problems with the conduct of a study at one or more sites, delays or problems in analyzing data, the need for additional analyses or data or the need to enroll additional patients, the negative impact of feedback from the FDA or other regulatory authorities on trial design or the analysis of results, the need to make protocol amendments or other unexpected issues, such as adverse events, in any of our clinical trials. These types of issues could lead to delays in the completion of a trial and announcement of results or impact the results of our trials. Further, we plan to seek marketing approvals in the United States, Canada, the European Union and other jurisdictions, which may require that we conduct clinical trials in foreign countries. Our ability to successfully initiate, enroll and complete a clinical trial in any foreign country is subject to numerous risks unique to conducting business in foreign countries, including: ● difficulty in establishing or managing relationships with clinical research organizations, or CROs, and physicians; ● different standards for the conduct of clinical trials; ● absence in some countries of established groups with sufficient regulatory expertise for review of AAV gene therapy protocols; ● our inability to locate qualified local partners or collaborators for such clinical trials; and ● the potential burden of complying with a variety of foreign laws, medical standards and regulatory requirements, including the regulation of pharmaceutical and biotechnology products and treatment. If we have difficulty enrolling a sufficient number of patients to conduct our clinical trials as planned, we may need to delay, limit or terminate ongoing or planned clinical trials in some or all localities, any of which would harm our business, financial condition, results of operations and prospects. Other events that may prevent successful or timely completion of clinical development include: ● delays in reaching a consensus with regulatory authorities or collaborators on trial design, implementation, management , or other aspects of the clinical trial; ● delays in reaching agreement on acceptable terms with prospective CROs and clinical trial sites; ● delays in opening clinical trial sites or obtaining required IRB or independent ethics committee approval at each clinical trial site; ● as a result of a serious adverse event, or SAE, or after an inspection of our clinical trial operations or trial sites or the decision by us or our collaborators, or the requirement of regulators or IRBs to suspend or terminate clinical research for various reasons, including noncompliance with regulatory requirements or a finding that the participants are being exposed to unacceptable health risks; ● failure by us, our collaboration partners, any CROs we engage, or any other third parties to adhere to clinical trial protocols or regulatory requirements; ● failure by us, our collaboration partners, any CROs we engage, or any other third parties to perform in accordance with the FDA’s good clinical practices, or GCPs, or applicable regulatory guidelines in the European Union; ● failure by physicians to adhere to delivery protocols leading to variable results; 63 Table of Contents ● delays in the testing, validation, manufacturing and delivery of our product candidates to the clinical sites, including delays by third parties with whom we have contracted to perform certain of those functions; ● insufficient or inadequate supply or quality of our product candidates or other materials necessary to conduct clinical trials of our product candidates; ● delays in having patients complete participation in a trial or return for post-treatment follow-up; ● clinical trial sites or patients dropping out of a trial at a rate higher than we anticipate; ● selection of clinical endpoints that require prolonged periods of clinical observation or analysis of the resulting data; ● receipt of negative or inconclusive clinical trial results; ● occurrence of SAEs associated with the product candidate that are viewed to outweigh its potential benefits; ● occurrence of SAEs in trials of the same class of agents conducted by other sponsors; ● changes in regulatory requirements and guidance that require amending or submitting new clinical protocols; or ● the cost of clinical trials of our product candidates may be greater than we anticipate. Any inability to successfully initiate or complete preclinical studies and clinical trials could result in additional costs and potential delays to us or impair our ability to generate revenues from product sales, regulatory and commercialization milestones and royalties. We do not know whether any of our preclinical studies or clinical trials will begin as planned, will need to be restructured, or will be completed on schedule, or at all. For example, the decision to refocus the Huntington’s disease program requires completion of new preclinical studies, preparation of a new IND, submission to the FDA, and resolution of any potential FDA objections before enrollment of the first patient in a new clinical trial. In addition, if we make manufacturing or formulation changes to our product candidates, such as we did in connection with our previous transition to an HEK 293-based production system from a baculovirus/Sf9 AAV production system or as a result of unanticipated clinical trial results, we may need to conduct additional studies to bridge our modified product candidates to earlier versions. Clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize our product candidates or allow our competitors to bring products to market before we do, which could impair our ability to successfully commercialize our product candidates and may harm our business, financial condition, results of operations and prospects. Additionally, if the results of our clinical trials are inconclusive or if there are safety concerns or SAEs associated with our product candidates, we may: ● be delayed in obtaining marketing approval for our product candidates, if we are able to do so at all; ● obtain approval for indications or patient populations that are not as broad as intended or desired; ● obtain approval with labeling that includes significant use or distribution restrictions, safety warnings or contraindications ; ● be subject to changes in the way the product is administered; 64 Table of Contents ● be required to perform additional clinical trials to support approval or be subject to additional post-marketing testing requirements; ● have regulatory authorities withdraw, or suspend, their approval of the product or impose restrictions on its distribution in the form of a Risk Evaluation and Mitigation Strategy, or REMS; ● be sued or otherwise become party to dispute proceedings; or ● experience damage to our reputation. Our product candidates may cause undesirable side effects or have other properties that could delay or prevent their further development or regulatory approval, limit their commercial potential or result in significant negative consequences following any potential marketing approval. Our proprietary antibodies, gene therapies and non-viral therapy product candidates may cause an immunologic reaction, or an immune response against the relevant product candidate. Other potential side effects associated with our gene therapy product candidates could include insertional oncogenesis, which is the process whereby the insertion of a functional gene near a gene that is important in cell growth or division results in uncontrolled cell division, which could potentially enhance the risk of malignant transformation. In past clinical trials that were conducted by others using non-AAV gene therapy vectors, several significant side effects were caused by gene therapy treatments, including reported cases of leukemia and death. For example, one of our competitors, Capsida Biotherapeutics, Inc., stated that it was not aware of significant safety signals in its preclinical program known as STXBP1, but its first patient dosed in its clinical program resulted in the death of a patient. Additionally, in a published review of patients with hepatocellular carcinomas, it was shown that a small subset contained an integrated genome sequence of wild-type AAV2, and it was suggested that AAV2 may be associated with insertional oncogenesis. I f our vectors demonstrate a similar adverse effect, or other adverse effects, we may be required to halt or delay further clinical development of our product candidates or withdraw the product from the market post-approval. Side effects could be caused by the product candidate or the administration process. If in the future we are unable to demonstrate what caused such side effects or are unable to modify the trial protocol adequately to address such side effects, the FDA, the European Commission, the EMA or other regulatory authorities could order us to cease further development of, or deny approval of, our product candidates for any or all targeted indications. For example, product candidates designed to “knock down” or reduce the expression of a gene or the production of its encoded protein could have effects on other parts of the body, or “off target” effects, that could result in unforeseen toxicity. Even if we are able to demonstrate that any future side effects are not product-related, and regulatory authorities do not order us to cease further development of our product candidates, such occurrences could affect patient recruitment or the ability of enrolled patients to complete the trial. Moreover, if we elect, or are required, to delay, suspend or terminate any clinical trial of any of our product candidates, the commercial prospects of such product candidates may be harmed and our ability to generate product revenues from any of these product candidates may be delayed or eliminated. Any of these occurrences may harm our ability to develop other product candidates and may harm our business, financial condition and prospects significantly. Additionally, if any of our product candidates receives marketing approval, the FDA could require us to adopt a REMS to ensure that the benefits outweigh its risks. We believe that the likelihood of the FDA requiring a REMS may be higher for treatments such as gene therapy. Such REMS may include, among other things, a medication guide outlining the risks of the product for distribution to patients and a communication plan to health care practitioners or the limitation of the use of the product to specifically trained neurosurgeons and/or certain centers. Furthermore, adverse events which were initially considered unrelated to the study treatment of the clinical trial may later be found to be caused by the study treatment. If we or others later identify undesirable side effects caused by our product candidate, several potentially significant negative consequences could result, including: ● regulatory authorities may suspend or withdraw approvals of such product candidate; ​ 65 Table of Contents ● the FDA or regulatory authorities outside the U.S. may impose a clinical hold or partial clinical hold, which could cause us or our collaborators to have to stop, delay or restrict further development; ​ ● we or our collaborators may, even without a clinical hold, decide to interrupt, delay or halt existing non-clinical studies and clinical trials or stop development; ​ ● we may have difficulty enrolling patients in our clinical trials and completing such trials on the timelines we expect or at all, or we may have to conduct additional non-clinical studies or clinical trials as part of a development program; ​ ● regulatory authorities may require additional warnings on the label; ​ ● we or our collaborators may be required to change the way a product candidate is administered or conduct additional clinical trials; ​ ● we or our collaborators may not be able ultimately to demonstrate, to the satisfaction of regulatory authorities, that our product candidates are safe and that the benefits outweigh the safety risks, and the applicable regulatory authorities may not approve the product candidate; ​ ● we or our collaborators could be subject to regulatory investigations or government enforcement actions, or be sued and held liable for harm caused to individuals exposed to or taking our product candidate; and ​ ● our reputation may suffer. ​ Any of these events could prevent us from achieving or maintaining market acceptance of our product candidates and could significantly harm our business, prospects, financial condition and results of operations. We may be unable to obtain orphan drug designation or exclusivity for any of our product candidates for which we seek such designation. If our competitors are able to obtain orphan drug exclusivity for products that constitute the “same drug” and treat the same indications as our product candidates, we may not be able to have competing products approved by the applicable regulatory authority for a significant period of time. For products for which we may obtain orphan drug designation or exclusivity, we may be unable to prevent the approval or marketing authorization of other similar products based upon regulatory decisions regarding product “sameness”. Regulatory authorities in some jurisdictions, including the United States and the European Union, may designate drugs for relatively small patient populations as orphan drugs. Under the Orphan Drug Act of 1983, or the Orphan Drug Act, the FDA may designate a product candidate as an orphan drug if it is intended to treat a rare disease or condition, which is generally defined as having a patient population of fewer than 200,000 individuals in the United States, or a patient population greater than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug or biological product will be recovered from sales in the United States. In the European Union, EMA’s Committee for Orphan Medicinal Products grants orphan drug designation to promote the development of products that are intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition affecting not more than five in 10,000 persons in the European Union. Additionally, orphan designation is granted for products intended for the diagnosis, prevention or treatment of a life-threatening, seriously debilitating or serious and chronic condition and when, without incentives, it is unlikely that sales of the drug in the European Union would be sufficient to justify the necessary investment in developing the drug or biologic product. Generally, if a product candidate with an orphan drug designation receives the first marketing approval for the indication for which it has such designation, the product is entitled to a period of marketing exclusivity, which precludes the applicable regulatory authority from approving another marketing application for a product that constitutes the same drug treating the same indication for that marketing exclusivity period, except in limited circumstances. If another sponsor receives such approval before we do (regardless of our orphan drug designation), we may be precluded from receiving marketing approval for our product for the applicable exclusivity period. The applicable period is seven years 66 Table of Contents in the United States and 10 years in the European Union. The exclusivity period in the United States can be extended by six months if the new drug application or BLA sponsor submits pediatric data that adequately respond to a written request from the FDA for such data. The exclusivity period in the European Union can be reduced to nine years if a product no longer meets the criteria for orphan drug designation or if the product is sufficiently profitable so that market exclusivity is no longer justified. Orphan drug exclusivity may be revoked if any regulatory agency determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the product to meet the needs of patients with the rare disease or condition. We believe that certain of our current programs may qualify for orphan drug designation. Even if we obtain orphan drug exclusivity for a product candidate, that exclusivity may not effectively protect the product candidate from competition because different drugs or biological products can be approved for the same condition. In the United States, even after an orphan drug is approved, the FDA may subsequently approve another drug or biological product for the same condition if the FDA concludes that the other drug or biological product is not the “same drug” or biological product or even if it is, the FDA determines that it is clinically superior in that it is shown to be safer or more effective or makes a major contribution to patient care. In September 2021, the FDA issued final guidance describing its current thinking on when a gene therapy product is the “same” as another product for purposes of orphan exclusivity. Under the guidance, if either the transgene or vector differs between two gene therapy products in a manner that does not reflect “minor” differences, the two products would be considered different drugs for orphan drug exclusivity purposes. The FDA will determine whether two vectors from the same viral class are the same on a case-by-case basis and may consider additional key features in assessing the sameness. In the European Union, marketing authorization may be granted to a similar medicinal product for the same orphan indication if: ● the second applicant can establish in its application that its medicinal product, although similar to the orphan medicinal product already authorized, is safer, more effective or otherwise clinically superior; ● the holder of the marketing authorization for the original orphan medicinal product consents to a second orphan medicinal product application; or ● the holder of the marketing authorization for the original orphan medicinal product cannot supply sufficient quantities of orphan medicinal product. On August 3, 2017, the Congress passed the FDA Reauthorization Act of 2017, or FDARA. FDARA, among other things, codified the FDA’s pre-existing regulatory interpretation to require that a drug sponsor demonstrate the clinical superiority of an orphan drug that is otherwise the same as a previously approved drug for the same rare disease in order to receive orphan drug exclusivity. The new legislation reverses prior precedent holding that the Orphan Drug Act unambiguously requires that the FDA recognize the orphan exclusivity period regardless of a showing of clinical superiority. The FDA and Congress may further reevaluate and revise the Orphan Drug Act and its regulations and policies. For example, in September 2021, the Court of Appeals for the Eleventh Circuit held that, for the purpose of determining the scope of orphan drug exclusivity, the term “same disease or condition” means the designated “rare disease or condition” and not the “indication or use” for which the product is approved. Subsequently, in another case, a federal district court in Washington, D.C. followed the reasoning of the Eleventh Circuit decision and that decision was appealed to the U.S. Court of Appeals for the D.C. Circuit. On February 3, 2026, the Consolidated Appropriations Act of 2026 was enacted into law. It overruled these court decisions and codified the FDA’s longstanding interpretation of the scope of orphan drug exclusivity to apply to “the same drug for the same approved use or indication within such designated rare disease or condition.” This change, which applies retroactively, expressly authorizes the FDA to approve multiple versions of the same orphan drug for different sub-indications and subpopulations, such as adult and pediatric patients or multiple variations of the same disease that are caused by different genetic variants. 67 Table of Contents In addition, to obtain orphan drug designation in the European Union, we would need to demonstrate that there exists no satisfactory method of diagnosis, prevention or treatment of the condition in question that has been authorized in the European Union or, if such method exists, the medicinal product will be of significant benefit to those affected by that condition. There is no assurance that we would be able to meet that standard for any of our product candidates. Further, if we do obtain orphan drug designation for a candidate product in the EU, we will not be able to maintain that designation if we are not able to show, to the satisfaction of the EU regulatory authorities, that the candidate product is of significant benefit to patients over available commercial products for the indication in the EU and any additional products that are ahead of our product candidate in clinical development for the indication. A potential breakthrough therapy designation by the FDA for our product candidates may not lead to a faster development or regulatory review or approval process, and it does not increase the likelihood that our product candidates will receive marketing approval. We may in the future seek a breakthrough therapy designation for some of our product candidates. A breakthrough therapy is defined as a drug or biological product that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug or biological product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For drugs or biological products that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Drugs designated as breakthrough therapies by the FDA may also be eligible for accelerated approval. Designation as a breakthrough therapy is within the discretion of the FDA. Accordingly, even if we believe one of our product candidates meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of a breakthrough therapy designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our product candidates qualify as breakthrough therapies, the FDA may later decide that the drugs or biological products no longer meet the conditions for qualification. A potential regenerative medicine advanced therapy designation by the FDA for our product candidates may not lead to a faster development or regulatory review or approval process, and it does not increase the likelihood that our product candidates will receive marketing approval. We have sought and may in the future seek a regenerative medicine advanced therapy, or RMAT, designation for some of our product candidates. Under the 21st Century Cures Act, or the Cures Act, to be eligible to receive RMAT designation from the FDA, a product candidate must be (a) considered a “regenerative medicine therapy” as defined in the Cures Act; (b) intended to treat, modify, reverse, or cure one or more serious or life-threatening diseases or conditions; and (c) indicated, in preliminary clinical evidence, to have the potential to address unmet medical needs for such diseases or conditions. Gene therapies, including genetically modified cells, that lead to a durable modification of cells or tissues may meet the definition in the Cures Act of a regenerative medicine therapy. The RMAT program is intended to facilitate efficient development and expedite review of such therapies. A new drug application or a BLA for a product candidate that has received an RMAT designation may be eligible for priority review or accelerated approval through (1) surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit or (2) reliance upon data obtained from a meaningful number of sites. Benefits of such designation also include early interactions with FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A product candidate that has received an RMAT designation that is granted accelerated approval and is subject to post-approval requirements may fulfill such requirements through the submission of clinical evidence, clinical studies, patient registries, or other sources of real world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval monitoring of all patients treated with such therapy prior to its approval. 68 Table of Contents RMAT designation is within the discretion of the FDA. Accordingly, even if we believe one of our other product candidates meets the criteria for RMAT designation, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of RMAT designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, the FDA may later decide that a product candidate that received RMAT designation no longer meets the conditions for designation. Alternatively, we or our collaborative partners may decide not to proceed with the clinical development of a product candidate that has previously received RMAT designation or decide to pursue such product candidate for an indication for which it has not received RMAT designation. Fast Track designation by the FDA may not actually lead to a faster development or regulatory review or approval process and does not assure FDA approval of our product candidate. If a drug is intended for the treatment of a serious or life-threatening condition and the drug demonstrates the potential to address unmet medical need for this condition, the drug sponsor may apply for FDA Fast Track designation. We have sought and may in the future seek such a designation for our product candidates. A Fast Track designation does not ensure that the product candidate will receive marketing approval or that approval will be granted within any particular timeframe. Thus, Fast Track products may not experience a faster development process, review or approval compared to conventional FDA procedures. In addition, the FDA may withdraw Fast Track designation if it believes that the designation is no longer supported by data from a product candidate’s clinical development program. Fast Track designation alone does not guarantee qualification for the FDA’s priority review procedures. Priority review designation by the FDA may not lead to a faster regulatory review or approval process and, in any event, does not assure FDA approval of our product candidate. If the FDA determines that a product candidate offers major advances in treatment or provides a treatment where no adequate therapy exists, the FDA may designate the product candidate for priority review. A priority review designation means that the FDA’s goal to review an application is six months, rather than the standard review period of ten months. We may request priority review for our product candidates. The FDA has broad discretion with respect to whether or not to grant priority review status to a product candidate, so even if we believe a particular product candidate is eligible for such designation or status, the FDA may decide not to grant it. Moreover, a priority review designation does not necessarily mean a faster regulatory review process or necessarily confer any advantage with respect to approval compared to conventional FDA procedures. Receiving priority review from the FDA does not guarantee approval within the six-month review cycle or thereafter. Where appropriate, we may pursue approval from the FDA, EMA or comparable foreign regulatory authorities through the use of accelerated registration pathways. If we are unable to obtain such approval, we may be required to conduct additional preclinical studies or clinical trials beyond those that we contemplate, which could increase the expense of obtaining, and delay the receipt of, necessary marketing approvals. Even if we receive accelerated approval from the FDA, EMA or comparable regulatory authorities, if our confirmatory trials do not verify clinical benefit, or if we do not comply with rigorous post-marketing requirements, the FDA, EMA or such other regulatory authorities may seek to withdraw accelerated approval. Where appropriate, we plan to pursue accelerated development strategies in areas of medical need. We may seek an accelerated approval pathway for one or more of our product candidates from the FDA, EMA or comparable foreign regulatory authorities. Under the accelerated approval provisions in the Federal Food, Drug, and Cosmetic Act, and the FDA’s implementing regulations, the FDA may grant accelerated approval to a product candidate designed to treat a serious or life-threatening condition that provides meaningful therapeutic benefit over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. The FDA considers a clinical benefit to be a positive therapeutic effect that is clinically meaningful in the context of a given disease, such as irreversible morbidity or mortality. For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign, or other measure that is thought to predict clinical benefit but is not itself a measure of 69 Table of Contents clinical benefit. An intermediate clinical endpoint is a clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. The accelerated approval pathway may be used in cases in which the advantage of a new drug or biologic over available therapy may not be a direct therapeutic advantage but is a clinically important improvement from a patient and public health perspective. If granted, accelerated approval is usually contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug’s or biologic’s clinical benefit. If such post-approval studies fail to confirm the drug’s or biologic’s clinical benefit, the FDA may withdraw its approval of the product. In addition, there can be no assurance that we will satisfy all FDA requirements, including new provisions, that govern accelerated approval. For example, with passage of the FDORA in December 2022, Congress modified certain provisions governing accelerated approval of drug and biologic products. Specifically, the new legislation authorized the FDA to require a sponsor to have its confirmatory clinical trial underway before accelerated approval is awarded and to submit progress reports on its post-approval studies to FDA every six months until the study is completed. Moreover, FDORA established expedited procedures authorizing FDA to withdraw an accelerated approval if certain conditions are met, including where a required confirmatory study fails to verify and describe the predicted clinical benefit or where evidence demonstrates the product is not shown to be safe or effective under the conditions of use. The FDA may also use such procedures to withdraw an accelerated approval if a sponsor fails to conduct any required post-approval study of the product with due diligence, including with respect to “conditions specified by the Secretary.” The new procedures include the provision of due notice and an explanation for a proposed withdrawal, and opportunities for a meeting with the Commissioner or the Commissioner’s designee and a written appeal, among other things. We will need to fully comply with these and other requirements in connection with the development and approval of any product candidate that qualifies for accelerated approval. More recently, in March 2023, the FDA issued draft guidance that outlines its current thinking and approach to accelerated approval. The FDA indicated that the accelerated approval pathway is commonly used for approval of oncology drugs due to the serious and life-threatening nature of cancer. Although single-arm trials have been commonly used to support accelerated approval, a randomized controlled trial is the preferred approach as it provides a more robust efficacy and safety assessment and allows for direct comparisons to an available therapy. To that end, the FDA outlined considerations for designing, conducting, and analyzing data for trials intended to support accelerated approvals of oncology therapeutics. Subsequently, in December 2024 and January 2025, the FDA issued additional draft guidance relating to accelerated approval. This guidance describes FDA’s views on what it means to conduct a confirmatory trial with due diligence and how the agency plans to interpret whether such a study needs to be underway at the time of approval. While this guidance is currently only in draft form and will ultimately not be legally binding even when finalized, we will need to consider the FDA’s guidance if we seek accelerated approval for any of our products in the future. Prior to seeking accelerated approval, we will seek feedback from the FDA, EMA or comparable foreign regulatory authorities and will otherwise evaluate our ability to seek and receive such accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we will decide to pursue or submit a BLA for accelerated approval or any other form of expedited development, review or approval. Similarly, there can be no assurance that after subsequent feedback from the FDA, EMA or comparable foreign regulatory authorities, we will continue to pursue or apply for accelerated approval or any other form of expedited development, review or approval, even if we initially decide to do so. Furthermore, if we decide to submit an application for accelerated approval, there can be no assurance that such submission or application will be accepted or that any expedited development, review or approval will be granted on a timely basis, or at all. The FDA, EMA or other comparable foreign regulatory authorities could also require us to conduct further studies prior to considering our application or granting approval of any type. A failure to obtain accelerated approval, review or approval for our product candidate would result in a longer time period to commercialization of such product candidate, could increase the cost of development of such product candidate and could harm our competitive position in the marketplace. 70 Table of Contents Even if we complete the necessary preclinical studies and clinical trials, the marketing approval process is expensive, time-consuming and uncertain and may prevent us from obtaining approvals for the commercialization of some or all of our product candidates. If we or any current or future collaborators are not able to obtain, or if there are delays in obtaining, required regulatory approvals, we or they may not be able to commercialize our products, and our ability to generate revenue may be materially impaired. Our product candidates and the activities associated with their development and commercialization, including their design, testing, manufacture, safety, efficacy, recordkeeping, labeling, storage, approval, advertising, promotion, sale and distribution, export and import, are subject to comprehensive regulation by the FDA and other regulatory agencies in the United States and by the EMA and comparable regulatory authorities in other countries. Failure to obtain marketing approval for a product candidate will prevent us from commercializing the product candidate. We have not received approval to market any of our product candidates from regulatory authorities in any jurisdiction. We have only limited experience in filing and supporting the applications necessary to gain marketing approvals and expect to rely on third-party CROs to assist us in this process. Securing marketing approval requires the submission of extensive preclinical and clinical data and supporting information to the various regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing regulatory approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities by, the relevant regulatory authority. Our product candidates may not be effective, may be only moderately effective or may prove to have undesirable or unintended side effects, toxicities or other characteristics that may preclude our obtaining marketing approval or prevent or limit commercial use. Further, the FDA may determine that we must provide additional evidence and data before approving a BLA or NDA for our candidate products. For example, the FDA reviews an application to determine whether there is “substantial evidence” to support a finding of effectiveness for the proposed product for its intended use(s). In February 2026, the Commissioner of FDA and the Director of Center for Biologics Evaluation and Research published an editorial in the New England Journal of Medicine in which they declared that, in most cases, the new default requirement for FDA approval of a new product will be one adequate and well-controlled pivotal clinical trial plus confirmatory evidence, rather than two pivotal clinical trials. In determining whether to rely on one trial, the FDA will focus on the single trial’s quality, including magnitude of effect, appropriateness of control arms, endpoint selection, statistical power, blinding, handling of missing data, biological plausibility and alignment with intermediate biomarkers. The FDA has long had authority to approve new products on the basis of one trial plus confirmatory evidence and, in recent years, the agency has exercised that authority with respect to certain types of products. The FDA now takes the position that this will be the new official default standard for most product candidates. At this point, it is unclear how this new policy will be implemented by the FDA and how, if at all, it will affect our clinical development programs. The FDA may also require that NDA or BLA submissions for our product candidates include pediatric data. Under the PREA, an NDA, BLA or supplement to an NDA or a BLA for certain drugs and biological products must contain data to assess the safety and effectiveness of the drug or biological product in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective, unless the sponsor receives a deferral or waiver from the FDA. Applicable legislation in the EU also requires sponsors to either conduct clinical trials in a pediatric population in accordance with a Pediatric Investigation Plan approved by the Pediatric Committee of the EMA or to obtain a waiver or deferral from the conduct of these studies by this Committee. For any of our product candidates for which we are seeking regulatory approval in the United States or the EU, we cannot guarantee that we will be able to obtain a waiver or alternatively complete any required studies and other requirements in a timely manner, or at all, which could result in associated reputational harm and subject us to enforcement action. Moreover, principal investigators for our future clinical trials may serve as scientific advisors or consultants to us and receive compensation in connection with such services. Under certain circumstances, we may be required to report some of these relationships to the FDA or comparable foreign regulatory authorities. The FDA or a comparable foreign regulatory authority may conclude that a financial relationship between us and a principal investigator has created a conflict of interest or otherwise affected interpretation of the study. The FDA or comparable foreign regulatory 71 Table of Contents authority may therefore question the integrity of the data generated at the applicable clinical trial site and the utility of the clinical trial itself may be jeopardized. This could result in a delay in approval, or rejection, of our marketing applications by the FDA or comparable foreign regulatory authority, as the case may be, and may ultimately lead to the denial of marketing approval of one or more of our product candidates. The process of obtaining marketing approvals, both in the United States and abroad, is expensive; may take many years if additional clinical trials are required, if approval is obtained at all and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. In the United States, for example, the application user fee to obtain FDA review of a marketing application is more than $4.6 million and may be higher in the future. Changes in marketing approval policies during the development period, in or the enactment of additional statutes or regulations, or in regulatory review for each submitted product application, may cause delays in the approval or rejection of an application. The FDA and comparable authorities in other countries have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent marketing approval of a product candidate. Any marketing approval we, or any current or future collaborators, ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable. Accordingly, if we or any current or future collaborators experience delays in obtaining approval or if we or they fail to obtain or retain approval of our product candidates and devices, the commercial prospects for our product candidates may be harmed and our ability to generate revenues could be materially impaired. Even if we obtain regulatory approval for a product candidate, our products will remain subject to regulatory oversight. Even if we obtain any regulatory approval for our product candidates, they will be subject to ongoing regulatory requirements for manufacturing, labeling, packaging, storing, advertising, promoting, sampling, record-keeping and submitting safety and other post-market information. Any regulatory approvals that we receive for our product candidates also may be subject to a REMS, limitations on the approved indicated uses for which the product may be marketed or to the conditions of approval or contain requirements for potentially costly post-marketing testing, including post-marketing studies or clinical trials, and surveillance to monitor the quality, safety and efficacy of the product. For example, the holder of an approved BLA is obligated to monitor and report adverse events and any failure of a product to meet the specifications in the BLA. FDA guidance advises that patients treated with some types of gene therapy undergo follow-up observations for potential adverse events for as long as 15 years. The holder of an approved BLA also must submit new or supplemental applications and obtain FDA approval for certain changes to the approved product, product labeling or manufacturing process. Advertising and promotional materials must comply with FDA rules and are subject to FDA review, in addition to other potentially applicable federal and state laws. In addition, product manufacturers and their facilities are subject to payment of user fees and continual review and periodic inspections by the FDA and other regulatory authorities for compliance with cGMP requirements and adherence to commitments made in the BLA or foreign marketing application. If we, or a regulatory authority, discover previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured or such regulatory authority disagrees with the promotion, marketing or labeling of that product, the regulatory authority may impose restrictions relative to that product, the manufacturing facility or us, including requiring recall or withdrawal of the product from the market or suspension of manufacturing. If we fail to comply with applicable regulatory requirements following approval of any of our product candidates, a regulatory authority may: ● issue a warning letter asserting that we are in violation of the law; ● seek an injunction or impose administrative, civil or criminal penalties or monetary fines; ● suspend or withdraw regulatory approval; 72 Table of Contents ● suspend any ongoing clinical trials; ● refuse to approve a pending BLA or comparable foreign marketing application, or any supplements thereto, submitted by us or our collaboration partners; ● restrict the marketing or manufacturing of the product; ● seize or detain the product or otherwise require the withdrawal of the product from the market; ● refuse to permit the import or export of products; or ● refuse to allow us to enter into supply contracts, including government contracts. Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. The occurrence of any event or penalty described above may inhibit our ability to commercialize our product candidates and adversely affect our business, financial condition, results of operations and prospects. In addition, we could be adversely affected by several significant administrative law cases decided by the U.S. Supreme Court in 2024. In Loper Bright Enterprises v. Raimondo , for example, the Court overruled Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc ., which for 40 years required federal courts to defer to permissible agency interpretations of statutes that are silent or ambiguous on a particular topic. The U.S. Supreme Court stripped federal agencies of this presumptive deference and held that courts must exercise their independent judgment when deciding whether an agency such as the FDA acted within its statutory authority under the Administrative Procedure Act, or the APA. Additionally, in Corner Post, Inc. v. Board of Governors of the Federal Reserve System , the Court held that actions to challenge a federal regulation under the APA can be initiated within six years of the date of injury to the plaintiff, rather than the date the rule is finalized. The decision appears to give prospective plaintiffs a personal statute of limitations to challenge longstanding agency regulations. Another decision, Securities and Exchange Commission v. Jarkesy , overturned regulatory agencies’ ability to impose civil penalties in administrative proceedings. These decisions could introduce additional uncertainty into the regulatory process and may result in additional legal challenges to actions taken by federal regulatory agencies, including the FDA and CMS, that we rely on. In addition to potential changes to regulations as a result of legal challenges, these decisions may result in increased regulatory uncertainty and delays and other impacts, any of which could adversely impact our business and operations. Further, our ability to develop and market new drug products may be impacted by litigation challenging the FDA’s approval of another company’s drug product. In April 2023, the U.S. District Court for the Northern District of Texas invalidated the approval by the FDA of mifepristone, a drug product which was originally approved in 2000 and whose distribution is governed by various measures adopted under a REMS. The Court of Appeals for the Fifth Circuit declined to order the removal of mifepristone from the market but did hold that plaintiffs were likely to prevail in their claim that changes allowing for expanded access of mifepristone, which the FDA authorized in 2016 and 2021, were arbitrary and capricious. In June 2024, the Supreme Court reversed that decision after unanimously finding that the plaintiffs (anti-abortion doctors and organizations) did not have standing to bring this legal action against the FDA. On October 11, 2024, the Attorneys General of three states (Missouri, Idaho and Kansas) filed an amended complaint in the district court in Texas challenging FDA’s actions. On January 16, 2025, the district court agreed to allow these states to file an amended complaint and continue to pursue this challenge. Thereafter, on September 30, 2025, the district court declined to dismiss the case and, instead, transferred it to the federal district court in the Eastern District of Missouri. Depending on the outcome of this litigation, our ability to develop new drug product candidates and to maintain approval of existing drug products could be delayed, undermined or subject to protracted litigation. In addition, FDA policies, and those of equivalent foreign regulatory agencies, may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. If we are slow or unable to adapt to changes in existing 73 Table of Contents requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability, which would harm our business, financial condition, results of operations and prospects. Disruptions at the FDA and other government agencies from funding cuts, personnel losses, regulatory reform, government shutdowns and other developments could hinder our ability to obtain guidance from the FDA regarding our clinical development programs and develop and secure approval of our product candidates in a timely manner, which would negatively impact our business. The FDA and comparable regulatory agencies in foreign jurisdictions, such as the EMA and Committee for Medicinal Products for Human Use, play an important role in the development of our product candidates by providing guidance on our clinical development programs and reviewing our regulatory submissions, including investigational new drug applications, requests for special designations and marketing applications. If these oversight and review activities are disrupted, then correspondingly our ability to develop and secure timely approval of our product candidates could be impacted in a negative manner. For example, the recent loss and retirement of FDA leadership and personnel could lead to disruptions and delays in FDA guidance, or review and approval of our product candidates. Pursuant to President Trump’s E.O. 14210, “Implementing the President’s ‘Department of Government Efficiency’ Workforce Optimization Initiative,” the Secretary of HHS announced on March 27, 2025, a reorganization and reduction in force across HHS of approximately 20,000 employees (82,000 to 62,000), with the FDA’s workforce of approximately 20,000 to decrease by 3,500 full-time employees. On July 14, 2025, following litigation reaching the U.S. Supreme Court, the administration began to carry out layoffs across HHS, including the FDA. In November 2025, a Congressional Continuing Resolution ended the government shutdown, providing full-year funding for the FDA for fiscal year 2026 through September 30, 2026 at approximately $7 billion with a slight increase in user fees for drug and device companies. Further, while the FDA’s review of marketing applications and other activities for new drugs and biologics is largely funded through the user fee program established under the Prescription Drug User Fee Act, or PDUFA, it remains unclear how the administration’s reduction in force and budget cuts will impact this program and the ability of the FDA to provide guidance and review our product candidates in a timely manner. For example, while the FDA reduction in force did not reportedly specifically target FDA reviewers, many operations, administrative and policy staff that help support such reviews were affected and those losses could lead to delays in PDUFA reviews and related activities. There have been several reports in which the FDA failed to meet a PDUFA goal date for approval of an NDA or a BLA due to heavy workload and limited resources. In addition, there is a risk that the reduction in force and budget cutbacks could threaten the integrity of the PDUFA program itself because, for the FDA to utilize user fees collected under PDUFA in the first place, a certain amount of non-user fee appropriations must be spent on the process for the review of applications plus certain other costs during the same fiscal year. There is also substantial uncertainty as to how regulatory reform measures being implemented by the Trump Administration across the government will impact the FDA and other federal agencies with jurisdiction over our activities. For example, since taking office, President Trump has issued a number of executive orders that could have a significant impact on the manner in which the FDA conducts its operations and engages in regulatory and oversight activities. These include E.O. 14192, “Unleashing Prosperity Through Deregulation,” January 31, 2025; E.O. 14212, “Establishing the President’s Make America Healthy Again Commission,” February 13, 2025; and E.O. 14219, “Ensuring Lawful Governance and Implementing the President’s ‘Department of Government Efficiency’ Deregulatory Initiative,” February 21, 2025. If these or other orders or executive actions impose constraints on the FDA’s ability to engage in oversight and implementation activities in the normal course, our business may be negatively impacted. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable. During the last several years the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and the SEC, have had to furlough critical employees and stop critical activities. If a prolonged 74 Table of Contents government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions and could impact our ability to access the public markets and obtain necessary capital to properly capitalize and continue our operations. For example, the federal government shut down on October 1, 2025, and did not reopen for 43 days. With the shutdown, the FDA issued a public notice stating that agency operations would continue to the extent permitted by law, such as activities necessary to address imminent threats to the safety of human life and activities funded by carryover user fee funds. The FDA declared that, during the shutdown period, it did not have legal authority to accept user fees assessed for fiscal year 2026 until fiscal year 2026 appropriation or Continuing Resolution for the FDA was enacted. As a result, the FDA was not able to accept any regulatory submissions for fiscal year 2026 that required a fee payment and that was submitted during the lapse period. In addition, the FDA indicated that some of its regulatory science research, crucial for advancing product innovation, safety, and quality, would be curtailed during the lapse period. At the same time, disruptions at the FDA and other government agencies may result from public health events similar to the COVID-19 pandemic. For example, during the pandemic, a number of companies announced receipt of complete response letters due to the FDA’s inability to complete required inspections for their applications. In the event of a similar public health emergency in the future, the FDA may not be able to continue its current pace and review timelines could be extended. Regulatory authorities outside the United States facing similar circumstances may adopt similar restrictions or other policy measures in response to a similar public health emergency and may also experience delays in their regulatory activities. Accordingly, if any of the foregoing developments and others impact the ability of the FDA to provide us guidance regarding our clinical development programs or delay the FDA’s review and processing of our regulatory submissions, including INDs, NDAs, or BLAs, our business would be negatively impacted. Further, any future government shutdown could impact our ability to access the public markets and obtain necessary capital to properly capitalize and continue our operations. We face significant competition in an environment of rapid technological change and the possibility that our competitors may achieve regulatory approval before us or develop therapies that are more advanced or effective than ours, which may harm our business and financial condition and our ability to successfully market or commercialize our product candidates. The biopharmaceutical industry is characterized by intense and dynamic competition to develop new technologies and proprietary therapies. Any product candidates that we successfully develop into products and commercialize may compete with existing therapies and new therapies that may become available in the future. While we believe that our gene therapy platform, non-viral therapeutics platform, product programs, product candidates and scientific expertise in the fields of proprietary antibodies, gene therapy, and neuroscience provide us with competitive advantages, we face potential competition from various sources, including larger and better-funded pharmaceutical, specialty pharmaceutical and biotechnology companies, as well as from academic institutions, governmental agencies and public and private research institutions. We are aware of several companies focused on developing their proprietary antibodies, AAV gene therapies, or non-viral therapeutics in various indications, as well as several companies addressing other methods for modifying genes and regulating gene expression. Any advances in antibody, gene therapy, or non-viral therapeutic technology made by a competitor may be used to develop therapies that could compete against any of our product candidates. We expect that our TRACER discovery platform, non-viral therapeutics platform, and clinical and preclinical programs will compete with a variety of therapies in development, including: ● Our anti-tau antibody program for AD will potentially compete with tau antibodies being developed by Lundbeck LLC , Merck & Co. , Inc. in collaboration with Teijin Limited, Eisai Co., Ltd., Janssen Pharmaceuticals, Inc., a subsidiary of Johnson & Johnson , UCB S.A., Bristol-Myers Squibb Company in collaboration with Prothena Corporation plc , along with several other companies; 75 Table of Contents ● Our tau silencing gene therapy program for AD will potentially compete with an antisense oligonucleotide program being developed by Ionis Pharmaceuticals, Inc. in collaboration with Biogen Inc.; ● Our TDP-43 small molecule will potentially compete with a variety of companies developing small-molecules for TDP-43, including: Dewpoint Therapeutics, Inc., WaveBreak Therapeutics, LLC, Molefy Pharma SL, and various academic groups; ● Our TRACER discovery platform will potentially compete with a variety of companies developing AAV capsids, including: 4D Molecular Therapeutics, Inc., Affinia Therapeutics Inc., Apertura Gene Therapy, LLC, Capsida Biotherapeutics, Inc., Capsigen, Inc., Dyno Therapeutics, Inc., Kate Therapeutics Inc. (acquired by Novartis), Sangamo Therapeutics, Inc., and Shape Therapeutics Inc.; and ● Our non-viral therapeutics platform will potentially compete with a variety of companies developing non-viral shuttles for the delivery of genetic medicines to the CNS, including: ABL Bio, Inc. in collaboration with Sanofi S.A. and separately in collaboration with GSK plc, Aliada Therapeutics, Inc. (acquired by AbbVie Inc.), Arrowhead Pharmaceuticals, Inc. in collaboration with Sarepta Therapeutics, Inc., BioArctic AB in collaboration with Eisai Co., Ltd., Denali Therapeutics Inc., F. Hoffmann-La Roche Ltd, JCR Pharmaceuticals Co., Ltd., Manifold Biotechnologies, Inc. in collaboration with F. Hoffman-La Roche Ltd., and Souffle Therapeutics, Inc. Many of our potential competitors, alone or with their strategic partners, have substantially greater financial, technical and other resources, such as larger research and development, clinical, marketing and manufacturing organizations. Mergers and acquisitions in the biotechnology and pharmaceutical industries, including recent transactions involving a number of gene therapy companies, may result in even more resources being concentrated among a smaller number of competitors. Smaller and other early-stage companies may also prove to be significant competitors, particularly through collaborative agreements with large and established companies. Our commercial opportunity could be reduced or eliminated if competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Even if our competitors are unsuccessful in developing and commercializing their product candidates, their preclinical and clinical findings may lead us to conclude that our own similar product candidates are unlikely to achieve the desired performance characteristics. As a result, we may modify our development plans for, or discontinue further research and development of, such product candidates. For example, several of our competitors have conducted clinical trials of anti-tau antisense oligonucleotide and antibody candidates with clinical data readouts in 2025 or are conducting clinical trials with expected readouts in 2026. It is possible that we will modify our development plans for, or discontinue further research and development of, VY7523 or VY1706 if any of these clinical data readouts suggest that either candidate will likely fail to achieve the desired performance characteristics. Competitors also may obtain FDA or other regulatory approval for their products more rapidly or earlier than us or may obtain orphan drug or other marketing exclusivity, which could result in our competitors establishing a strong market position before we are able to enter the market or reducing the number of available subjects for enrollment in our clinical trials to support regulatory submissions and approvals of our product. Additionally, technologies developed or acquired by our competitors may render our potential product candidates uneconomical or obsolete, and we may not be successful in marketing our product candidates against competitors. These third parties also compete with us in recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites, and registering patients for clinical trials. In addition, as a result of the expiration or successful challenge of our patent rights, we could face more litigation with respect to the validity and scope of patents relating to our competitors’ products. The availability of our competitors’ products could limit the demand and the price we are able to charge for any products that we may develop and commercialize. If we are not able to compete effectively against potential competitors, our business will not grow, and our financial condition and operations will be harmed. 76 Table of Contents Even if we obtain and maintain approval for our product candidates from the FDA, we may never obtain approval for our product candidates outside of the United States, which would limit our market opportunities and adversely affect our business. Approval of a product candidate in the United States by the FDA does not ensure approval of such product candidate by regulatory authorities in other countries or jurisdictions, and approval by one foreign regulatory authority does not ensure approval by regulatory authorities in other foreign countries or by the FDA. Sales of our product candidates outside of the United States will be subject to foreign regulatory requirements governing clinical trials and marketing approval. Even if the FDA grants marketing approval for a product candidate, comparable regulatory authorities of foreign countries also must approve the manufacturing and marketing of the product candidates in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from, and more onerous than, those in the United States, including additional preclinical studies or clinical trials or manufacturing control requirements. In many countries outside the United States, a product candidate must be separately approved for reimbursement before it can be approved for sale in that country. In some cases, the price that we intend to charge for our products, if approved, is also subject to approval. We intend to submit a marketing authorization application to EMA for approval of our product candidates in the European Union but obtaining such approval from the European Commission following the opinion of EMA is a lengthy and expensive process. Even if a product candidate is approved, the FDA or the European Commission may limit the indications for which the product may be marketed, require extensive warnings on the product labeling or require expensive and time-consuming additional clinical trials or reporting as conditions of approval. Regulatory authorities in countries outside of the United States and the European Union also have requirements for approval of product candidates with which we must comply prior to marketing in those countries. Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our product candidates in certain countries. Further, clinical trials conducted in one country may not be accepted by regulatory authorities in other countries. Regulatory approval for any of our product candidates may be withdrawn. If we fail to comply with the regulatory requirements, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed and our business, financial condition, results of operations and prospects will be harmed. Additionally, we could face heightened risks with respect to obtaining marketing authorization in the United Kingdom as a result of the withdrawal of the United Kingdom from the European Union, commonly referred to as Brexit. The United Kingdom is no longer part of the European Single Market and EU Customs Union. As of January 1, 2025, the Medicines and Healthcare Products Regulatory Agency, or MHRA, is responsible for approving all medicinal products destined for the United Kingdom market (i.e., Great Britain and Northern Ireland). On April 28, 2025, the United Kingdom Parliament adopted amendments to improve and strengthen the United Kingdom’s clinical trials regulatory regime; they are scheduled to take effect on April 28, 2026. These changes were needed since the current United Kingdom requirements are based upon the now-repealed EU Clinical Trials Directive (2001/20/EC), which has been replaced by the CTR. Since the United Kingdom left the EU prior to the date on which the CTR took effect, the United Kingdom legal framework did not benefit from the same revisions as occurred at EU level. Further, as of January 1, 2025, a new international recognition procedure, or IRP, will apply, which intends to facilitate approval of pharmaceutical products in the UK. The IRP is open to applicants that have already received an authorization for the same product from one of the MHRA’s specified Reference Regulators, or RRs. The RRs notably include EMA and regulators in the EU/European Economic Area member states for approvals in the EU centralized procedure and mutual recognition procedure as well as for the FDA (for product approvals granted in the U.S.). However, the concrete functioning of the IRP is currently unclear. Any delay in obtaining, or an inability to obtain, any marketing approvals, may force us or our collaborators to restrict or delay efforts to seek regulatory approval in the UK for our product candidates, which could significantly and materially harm our business. In addition, foreign regulatory authorities may change their approval policies and new regulations may be enacted. For instance, the EU pharmaceutical legislation is currently undergoing a complete review process, in the context of the Pharmaceutical Strategy for Europe initiative, launched by the European Commission in November 2020. The European Commission’s proposal for revision of several legislative instruments related to medicinal products (including potentially reducing the duration of regulatory data protection and revising the eligibility for expedited 77 Table of Contents pathways) was published on April 26, 2023. On June 4, 2025, after almost two years of negotiations among the EU Member States, the Council of the European Union adopted its position on the proposed overhaul of the EU general pharmaceutical legislative framework, which is known as the new Pharma Package. Thereafter, on December 11, 2025, the European Parliament and Council reached a provisional political agreement on the legislation, which is expected to be adopted by mid-2026. The revisions may have a significant impact on the pharmaceutical industry and our business. They would, among other things, set a baseline period of eight years of data exclusivity and one year of market exclusivity with possible extensions for new indications up to a maximum of 11 years total. There will likely be a transition period of 24 months, with the changes taking effect in mid-2028. We expect that we will be subject to additional risks in commercializing any of our product candidates that receive marketing approval outside the United States, including tariffs, trade barriers and regulatory requirements; economic weakness, including inflation, increasing interest rates, or political instability in particular foreign economies and markets; compliance with tax, employment, immigration and labor laws for employees living or traveling abroad; foreign currency fluctuations, which could result in increased operating expenses and reduced revenue, and other obligations incident to doing business in another country; and workforce uncertainty in countries where labor unrest is more common than in the United States. If approved, our product candidates that are licensed and regulated as biologics may face competition from biosimilars approved through an abbreviated regulatory pathway. The Biologics Price Competition and Innovation Act of 2009, or BPCIA, was enacted as part of the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Affordability Reconciliation Act, or collectively, the ACA, to establish an abbreviated pathway for the approval of biosimilar and interchangeable biological products. The regulatory pathway establishes legal authority for the FDA to review and approve biosimilar biologics, including the possible designation of a biosimilar as “interchangeable” based on its similarity to an approved biologic. Under the BPCIA, a reference biological product is granted 12 years of data exclusivity from the time of first licensure of the product, and the FDA will not accept an application for a biosimilar or interchangeable product based on the reference biological product until four years after the date of first licensure of the reference product. In addition, the licensure of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still develop and receive approval of a competing biologic, so long as its BLA does not rely on the reference product or sponsor’s data, or the company does not submit the application as a biosimilar application. We believe that any of the product candidates we develop as a biological product under a BLA should qualify for the 12-year period of exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider the subject product candidates to be reference products for competing products, potentially creating the opportunity for biosimilar competition sooner than anticipated. For example, in October 2025, the FDA issued draft guidance which proposes to eliminate the need for sponsors of biosimilar products to conduct comparative human clinical efficacy studies, allowing them to rely instead on analytical testing to demonstrate product differences from a reference product. Moreover, the extent to which a biosimilar, once approved, will be substituted for any one of the reference products in a way that is similar to traditional generic substitution for non-biological products will depend on a number of marketplace and regulatory factors that are still developing. Nonetheless, the approval of a biosimilar to our product candidates would have a material adverse impact on our business due to increased competition and pricing pressure. 78 Table of Contents Risks Related to Third Parties To date, substantially all of our revenue has been derived from our ongoing collaborations and licensing agreements with Neurocrine, Novartis, and Alexion, and from our prior collaborations with Sanofi Genzyme Corporation, AbbVie Biotechnology Ltd and AbbVie Ireland Unlimited Company. I f any ongoing or future collaboration, option and license, or license agreements were to be terminated, our business financial condition, results of operations and prospects could be harmed. To date, substantially all of our revenue has been derived from our ongoing collaborations and licensing agreements with Neurocrine, Novartis, and Alexion and from our prior collaborations with Sanofi Genzyme, AbbVie Biotechnology Ltd and AbbVie Ireland Unlimited Company. If any ongoing or future collaboration, option and license, or license agreements were to be terminated, our business financial condition, results of operations and prospects could be harmed. For instance, in April 2025, Neurocrine deprioritized two programs against undisclosed targets pursuant to the 2019 Neurocrine Collaboration Agreement, and in October 2025, Novartis notified us of its intent to partially terminate the 2022 Novartis Option and License Agreement with respect to the two discovery stage programs against undisclosed targets effective February 1, 2026. In both cases, the rights to the discontinued programs were returned to us. Our ability to generate revenues from these arrangements will depend on our collaborators’ success in performing the functions assigned to them in these arrangements. Our current collaborators or any future collaborator might not be successful in obtaining approvals for the product candidates arising from our collaboration or commercializing or manufacturing the resulting products. Further, such collaborator’s objectives in connection with the collaboration may not be consistent with our best interests. With respect to the rights granted to a collaborator by us, the collaborator could take actions that may be adverse to us, or it could halt, slow, or deprioritize its development and commercialization efforts under the collaboration. In any such instances, our business, financial condition, results of operations and prospects could be materially harmed. We may seek to enter into collaborations and out-licensing transactions in the future with other third parties. If we are unable to enter into such collaborations or out-licensing transactions, or if these collaborations or out-licensing transactions are not successful, our business could be adversely affected. We have entered into collaboration agreements or capsid license agreements with Neurocrine, Novartis, Transition Bio and other collaborators since 2019. We may seek to enter into additional collaborations in the future, including sales, marketing, distribution, development, option, licensing, and/or broader collaboration agreements. Our likely collaborators, optionees, and licensees include large and mid-size pharmaceutical companies, regional and national pharmaceutical companies, biotechnology companies, and medical device manufacturers. However, we may not be able to enter into additional collaborations or option and license transactions on favorable terms, or at all. Our ability to generate revenues from our collaborations and option and license transactions will depend on our and our collaborators’, optionees’, and licensees’ abilities to successfully perform the functions assigned to each of us in these arrangements. In addition, our collaborators, optionees, and licensees might have the ability to abandon research or development projects and terminate applicable agreements. Moreover, an unsuccessful outcome in any clinical trial for which our competitors, collaborators, optionees, or licensees are responsible could be harmful to the public perception and prospects of our proprietary antibody program, gene therapy and other platforms and programs. Our relationship with any current or future collaborators, optionees, or licensees may pose several risks, including the following: ● collaborators, optionees, and licensees have significant discretion in determining the amount and timing of the efforts and resources that they will apply to these collaborations and option and license transactions; ● collaborators, optionees, or licensees may not perform their obligations as expected or desired; 79 Table of Contents ● the preclinical studies and clinical trials conducted as part of these collaborations or by our licensees may not be successful; ● collaborators, optionees, or licensees may not pursue development and commercialization of any product candidates that achieve regulatory approval or may elect not to continue or renew development or commercialization programs based on preclinical study or clinical trial results, changes in the collaborators’, optionees’, or licensees’ strategic focus or available funding or external factors, such as an acquisition, which divert resources or create competing priorities; ● collaborators, optionees, or licensees may delay preclinical studies and clinical trials, provide insufficient funding for preclinical studies and clinical trials, stop a preclinical study or clinical trial or abandon a product candidate, repeat or conduct new preclinical studies or clinical trials or require a new formulation of a product candidate for preclinical studies or clinical trials; ● we may not have access to, or may be restricted from disclosing, certain information regarding product candidates being developed or commercialized under a collaboration or by a licensee and, consequently, may have limited ability to inform our stockholders about the status of such product candidates; ● collaborators, optionees, or licensees could independently develop, or develop with third parties, products that compete directly or indirectly with our product candidates if the collaborators, optionees, or licensees believe that competitive products are more likely to be successfully developed or can be commercialized under terms that are more economically attractive than ours; ● product candidates developed in collaboration with us or by a licensee may be viewed by our collaborators or licensees as competitive with their own product candidates or products, which may cause collaborators or licensees to cease to devote resources to the commercialization of our product candidates; ● a collaborator or licensee with marketing and distribution rights to one or more of our product candidates that achieve regulatory approval may not commit sufficient resources to the marketing and distribution of any such product candidate; ● disagreements with collaborators, optionees, or licensees, including disagreements over proprietary rights, contract interpretation or the preferred course of development of any product candidates, may cause delays or termination of the research, development or commercialization of such product candidates, may lead to additional responsibilities or expenses for us with respect to such product candidates (in the case of collaborations) or may result in litigation or arbitration, any of which would be time-consuming and expensive; ● in collaboration, licensing, and option arrangements where we have licensed intellectual property rights to collaborators, licensees, and optionees who have the right to control prosecution of the licensed intellectual property rights, disputes may arise with respect to the prosecution strategy for the relevant intellectual property rights, which may impair our ability to pursue our preferred prosecution strategy or achieve the desired protection from any relevant patents; ● collaborators, optionees, or licensees may not properly maintain or defend our intellectual property rights or may use our proprietary information in such a way as to invite litigation that could jeopardize or invalidate our intellectual property or proprietary information or expose us to potential litigation; ● disputes may arise with respect to the ownership or inventorship of intellectual property developed pursuant to our collaborations or option and license transactions; 80 Table of Contents ● collaborators, optionees, or licensees may infringe the intellectual property rights of third parties, which may expose us to litigation and potential liability; ● the terms of our collaboration or license agreement may restrict us from entering into certain relationships with other third parties, thereby limiting our options; and ● collaborations or licenses may be terminated for the convenience of the collaborator or licensee and, if terminated, we could be required to raise additional capital to pursue further development or commercialization of the applicable product candidates. Collaboration and license agreements may not lead to the development or commercialization of product candidates in the most efficient manner, or at all. If our collaborations or option and license transactions do not result in the successful development and commercialization of products, or if one of our collaborators, optionees, or licensees terminates its agreement with us, we may not receive any future research funding or milestone or royalty payments under the collaboration or option and license transactions. If we do not receive the funding we expect under these agreements, our development of our product candidates could be delayed, and we may need additional resources to develop our product candidates. In the event we are unable to achieve milestones necessary to demonstrate progress on our programs relevant to our ongoing collaborations with Neurocrine or Novartis or our collaboration programs are deprioritized by our collaborators, Neurocrine or Novartis may be unwilling to fund these programs at the desired levels or at all, which could require us to fund these programs to a greater extent than we have expected, to decline to pursue certain program objectives or to discontinue one or more of the programs. Additionally, subject to its contractual obligations to us, if a collaborator, optionee, or licensee of ours were to be involved in a business combination, it might deemphasize or terminate the development or commercialization of any product candidate optioned or licensed to it by us. If one of our collaborators, optionees, or licensees terminates its agreement with us, we may find it more difficult to attract new collaborators, optionees, or licensees, and the perception of us in the business and financial communities could be adversely affected. All of the risks relating to product development, regulatory approval and commercialization described in this periodic report also apply to the activities of our collaborators, optionees, and licensees. We will face significant competition in seeking appropriate collaborators, optionees, and licensees, and the negotiation process is time-consuming and complex. Our ability to reach a definitive collaboration or license agreement with any future collaborators, optionees, and licensees will depend, among other things, upon our assessment of the collaborator’s, optionee’s, or licensee’s resources and expertise, the terms and conditions of the proposed collaboration or option and license transactions and the proposed collaborator’s, optionee’s, or licensee’s evaluation of several factors. Those factors may include the design or results of clinical trials, the likelihood of approval by the FDA or similar regulatory authorities outside the United States, the potential market for the subject product candidate, the costs and complexities of manufacturing and delivering such product candidate to patients, the potential of competing products, the existence of uncertainty with respect to our ownership of technology, which can exist if there is a challenge to such ownership without regard to the merits of the challenge, and industry and market conditions generally. The collaborator, optionee, or licensee may also consider alternative product candidates or technologies for similar indications that may be available to collaborate on and whether such a collaboration or option and license transaction could be more attractive than the one with us for our product candidate. We may also be restricted under future license agreements from entering into agreements on certain terms with potential collaborators, optionees, or licensees. In addition, there have been a significant number of recent business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators, optionees, and licensees. If we are unable to reach agreements with suitable collaborators on a timely basis, on acceptable terms, or at all, we may have to curtail the development of a product candidate, reduce or delay its development program or one or more of our other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, or increase our expenditures and undertake development or commercialization activities at our own expense. If we elect to fund and undertake development or commercialization activities on our own, we may need to obtain additional expertise and additional capital, which may not be available to us on acceptable terms, or at all. If we fail to enter into collaborations or option and license transactions and do not have sufficient funds or expertise to undertake the necessary development and commercialization activities, we may not be able to further develop our product candidates or bring them to market or continue to develop our proprietary antibody program or gene therapy platforms and 81 Table of Contents programs. If we license rights to product candidates, we may not be able to realize the benefit of such transactions if we are unable to successfully integrate them with our existing operations and company culture. We and our collaborators have relied, and we and our collaborators expect to continue to rely, on third parties to conduct, supervise and monitor our preclinical studies and clinical trials, and if these third parties perform in an unsatisfactory manner, our business could be harmed. We and our collaborators expect to rely on CROs, clinical trial sites, and other vendors to ensure our preclinical studies and clinical trials are conducted properly and on time. We and our collaborators may also engage third parties such as clinical data management organizations, medical institutions and clinical investigators to conduct or assist in our clinical trials or other preclinical and clinical research and development work. While we and our collaborators will have agreements governing their activities, we and our collaborators will have limited influence over their actual performance. We and our collaborators will control only certain aspects of our third-party service providers’ activities. Nevertheless, we and our collaborators will be responsible for ensuring that each of our preclinical studies and clinical trials is conducted in accordance with the applicable protocol, legal, quality, regulatory and scientific standards. Our reliance on these third parties does not relieve us of our regulatory responsibilities. For example, the multiple ascending dose study of VY7523 in Alzheimer’s patients is currently ongoing at several locations. Additionally, we expect to initiate the clinical study of VY1706 at multiple sites in the United States and Canada. If any locations terminate a particular clinical trial, we or our collaborators would be required to find other parties or locations to conduct such clinical trial. We and our collaborators may be unable to find a new party to conduct new trials of our product candidates or obtain clinical supply of our product candidates or AAV vectors for such trials. If we or our collaborators elect to internalize some or all activities related to the conduct of our preclinical studies or clinical trials that are currently performed by our third-party service providers, or if we or our collaborators are required to do so due to a service provider’s termination of our relationship, then we or our collaborators may be required to source additional technology and personnel in order to perform the relevant activities. We and our collaborators may be unsuccessful in our efforts to internalize some or all relevant activities, either on the desired timeline or at all. We, our collaborators, and our third-party service providers are required to comply with the FDA’s GLPs and GCPs for conducting, recording and reporting the results of IND enabling preclinical studies and clinical studies to assure that the data and reported results are credible and accurate and that the rights, integrity and confidentiality of clinical trial participants are protected. We and our collaborators are also required to register ongoing clinical trials and post the results of completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within specified timeframes. The FDA enforces these GLPs and GCPs through periodic inspections of trial sponsors, principal investigators, clinical trial sites, and laboratories at which the FDA may determine that our preclinical studies and clinical trials did not comply with GLPs or GCPs. If we, our collaborators, or our third-party service providers fail to comply with applicable GLPs or GCPs, the preclinical or clinical data generated in our future preclinical studies or clinical trials may be deemed unreliable and the FDA may require us to perform additional preclinical studies or clinical trials before approving the relevant INDs or marketing applications. In addition, our future clinical trials will require a sufficient number of patients to evaluate the safety and effectiveness of our product candidates. Accordingly, if we, our collaborators, or our third-party service providers fail to comply with these regulations or fail to recruit a sufficient number of patients, we may be required to repeat such preclinical studies or clinical trials, which would delay the regulatory approval process. Failure to comply can also result in fines, adverse publicity, and civil and criminal sanctions. Our third-party service providers are not our employees, and we and our collaborators are therefore unable to directly monitor whether or not they devote sufficient time, attention, expertise and resources to our clinical and nonclinical programs. These third-party service providers may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical trials or other drug development activities that could harm our competitive position. If our third-party service providers do not successfully carry out their contractual duties or obligations, fail to meet expected deadlines, or if the quality or accuracy of the preclinical or clinical data they obtain is compromised due to the failure to adhere to our clinical protocols or regulatory requirements, or for any other reasons, our preclinical studies or clinical trials may be extended, delayed or terminated, and we may not be able to obtain regulatory approval for, or successfully commercialize our product candidates. As a result, our financial results 82 Table of Contents and the commercial prospects for our product candidates could be harmed, our costs could increase, and our ability to generate revenues could be delayed. Risks Related to Manufacturing Our gene therapies, non-viral therapeutics, and other biological modalities are novel, complex and difficult to manufacture. We could experience manufacturing problems that result in delays in the development or commercialization of our product candidates or otherwise harm our business. The manufacture of gene therapy, non-viral therapeutic, and other biological products is technically complex and necessitates substantial expertise and capital investment. Production difficulties caused by unforeseen events may delay the availability of material for our clinical studies. To meet the requirements of our current and planned future trials we have developed a flexible AAV gene therapy manufacturing platform that is based on proprietary technology and provides a scalable process for preclinical and clinical AAV production. We are using a HEK 293 based transient transfection manufacturing process to support our preclinical research activities. As the field advances, we will continue to evaluate additional novel manufacturing technologies that may be suitable for future clinical and commercial manufacturing. We presently contract with third parties for the manufacturing of our program materials for our proprietary antibody and gene therapy product candidates. We have also built an onsite, state-of-the-art process research and development facility to enable the manufacturing of preclinical AAV gene therapy vectors for large animal studies, including IND enabling GLP toxicology materials. We do not currently have our own clinical or commercial scale manufacturing. The use of contract manufacturing and reliance on collaboration partners is relatively cost-efficient and eliminates the need for our direct investment in manufacturing facilities and additional staff early in development. Although we rely on contract manufacturers, we have personnel with manufacturing and quality experience to oversee our contract manufacturers. To date, our third-party manufacturers have met our manufacturing requirements for our program materials. We expect third-party manufacturers to be capable of providing sufficient quantities of our program materials to meet anticipated clinical trial scale demands. To meet our projected needs for clinical and commercial manufacturing, third parties with whom we currently work might need to increase their scale of production, or we may need to secure additional suppliers as part of our external manufacturing network. We believe that there are alternate sources of supply for our program materials that can satisfy our clinical and commercial requirements, although we cannot be certain that identifying and establishing relationships and technology transfers with such sources, if necessary, would not result in significant delay or material additional costs. However, if a third-party manufacturer decided to not enter into a new contract with us for program materials or if they did not have the capacity to meet our needs for program materials, we may be required to contract with additional suppliers on terms which may be less favorable to us or would result in additional material costs. To date, our third-party manufacturers have met our quality standards for our program materials. The manufacturers of pharmaceutical products must comply with strictly enforced cGMP requirements, state and federal regulations, as well as foreign requirements when applicable. Any failure by us or our contract manufacturing organizations to adhere to or document compliance to such regulatory requirements could lead to a delay or interruption in the availability of our program materials for clinical study. If we or our manufacturers were to fail to comply with the FDA, EMA, or other regulatory authority, it could result in sanctions being imposed on us, including clinical holds, fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of product candidates or products, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of our product candidates. Our potential future dependence upon others for the manufacture of our product candidates may also adversely affect our future profit margins and our ability to commercialize any product candidates that receive regulatory approval on a timely and competitive basis. Biological products are inherently difficult to manufacture. Our program materials are manufactured using technically complex processes requiring specialized equipment and facilities, highly specific raw materials, cells, and reagents, and other production constraints. Several of these raw materials, cells, and reagents are provided by a limited 83 Table of Contents number of suppliers. Even though we aim to have backup supplies and suppliers of raw materials, cells, and reagents whenever possible, we cannot be certain they will be sufficient if our primary sources are unavailable. A shortage of a critical raw material, cell line, or reagent, or a technical issue during manufacturing may lead to delays in clinical development or commercialization plans. Any changes in the manufacturing of components of the raw materials we use could result in unanticipated or unfavorable effects on our manufacturing processes, including delays. Delays in obtaining regulatory approval of our or our collaborators’ manufacturing processes and facilities or disruptions in such manufacturing processes may delay or disrupt our commercialization efforts. Until recently, no cGMP gene therapy manufacturing facility in the United States had received approval from the FDA for the manufacture of an approved gene therapy product. Before we can begin to commercially manufacture a product candidate in our own facility, or the facility of a collaborator, we must obtain regulatory approval from the FDA for our manufacturing process and our collaborator’s facility. A manufacturing authorization must also be obtained from the appropriate European Union regulatory authorities. Until recently, no cGMP gene therapy manufacturing facility in the United States had received approval from the FDA for the manufacture of an approved gene therapy product and, therefore, the timeframe required for us to obtain such approval is uncertain. In addition, we must pass a pre-approval inspection of our or our collaborator’s manufacturing facility by the FDA and other relevant regulatory authorities before any of our product candidates can obtain marketing approval. In order to obtain approval, we will need to ensure that all of our processes, methods and equipment are compliant with cGMP, and perform extensive audits of vendors, contract laboratories and suppliers. If any of our vendors, contract laboratories or suppliers is found to be out of compliance with cGMP, we may experience delays or disruptions in manufacturing while we work with these third parties to remedy the violation or while we work to identify suitable replacement vendors. The cGMP requirements govern quality control of the manufacturing process and documentation policies and procedures. In complying with cGMP, we will be obligated to expend time, money and effort in production, record keeping and quality control to assure that the product meets applicable specifications and other requirements. If we fail to comply with these requirements, we would be subject to possible regulatory action and may not be permitted to sell any products that we may develop. Failure to comply with ongoing regulatory requirements could cause us to suspend production or put in place costly or time-consuming remedial measures. The regulatory authorities may, at any time, following approval of a product for sale, audit the manufacturing facilities for such product or institute biennial inspections. If any such inspection or audit identifies a failure to comply with applicable regulations, or if a violation of product specifications or applicable regulations occurs independent of such an inspection or audit, the relevant regulatory authority may require remedial measures that may be costly or time-consuming to implement and that may include the temporary or permanent suspension of a clinical trial or commercial sales or the temporary or permanent closure of a manufacturing facility. Any such remedial measures imposed upon our third-party manufacturers, our collaborators, or us could harm our business, financial condition, results of operations and prospects. If our third-party manufacturers, our collaborators, or we fail to comply with applicable cGMP regulations, FDA and foreign regulatory authorities can impose regulatory sanctions including, among other things, refusal to approve a pending application for a new product candidate or suspension or revocation of a pre-existing approval. Such an occurrence may cause our business, financial condition, results of operations and prospects to be harmed. Additionally, if supply from any third-party manufacturers is delayed or interrupted, there could be a significant disruption in the supply of our clinical or commercial material. We have agreements in place with our contract manufacturers pursuant to which we are collaborating on cGMP manufacturing processes and analytical methods for the manufacture of our proprietary antibody and AAV product candidates. However, we are dependent on one third-party manufacturer to produce our AAV and one for the tau antibody clinical product candidates. Therefore, if we are unable to enter into an agreement with our contract manufacturers to manufacture clinical or commercial material for our product programs, or if our agreement with our contract manufacturers were terminated, we would have to find suitable alternative manufacturers. This could delay our or our collaborators’ ability to conduct clinical trials or commercialize our current and future product candidates. The regulatory authorities also may require additional trials if a new 84 Table of Contents manufacturer is relied upon for commercial production. Switching manufacturers may involve substantial costs and could result in a delay in our desired clinical and commercial timelines. Any contamination in the manufacturing process for our products or product candidates, shortages of raw materials, cells or reagents, or failure of any of our key suppliers to deliver necessary components could result in delays in our clinical development or marketing schedules. Given the nature of biologics manufacturing, there is a risk of contamination. Any contamination could adversely affect our ability to produce product candidates on schedule and could, therefore, harm our results of operations and cause reputational damage. Some of the raw materials required in our manufacturing process are derived from biologic sources. Such raw materials are difficult to procure and may be subject to contamination or recall. A material shortage, contamination, recall or restriction on the use of biologically derived substances in the manufacture of our product candidates could adversely impact or disrupt the commercial manufacturing or the production of clinical material, which could adversely affect our development timelines and our business, financial condition, results of operations and prospects. Failure to obtain access to or to protect intellectual property related to the manufacturing of our products or product candidates may result in changes, delays and/or inability to manufacture such products or product candidates. The intellectual property related to the manufacture of biological products is complex. If we are unable to maintain control of manufacturing technology such as our trade secrets, or we are unable to protect ongoing improvements comprehensively and in a sufficient number of jurisdictions, it would impact our ability to produce products for commercial sale or product candidates for preclinical testing or clinical trials and our development timelines and operations timelines could be adversely affected. We presently manufacture our AAV product candidates using a mammalian cell system. We are aware of third parties that also use this system in the manufacture of their products and who hold intellectual property on their AAV manufacturing systems. If we determine that access to certain third-party intellectual property is necessary for the manufacturing of our products and product candidates and are unable to license or otherwise access this intellectual property, it would impact our ability to produce products for commercial sale or product candidates for preclinical testing or clinical trials and our development timelines and operations timelines could be adversely affected. Risks Related to Our Business Operations We may not be successful in our efforts to identify or discover additional product candidates and may fail to capitalize on programs or product candidates that may be a greater commercial opportunity, or for which there is a greater likelihood of success. The success of our business depends upon our ability to identify, develop and commercialize product candidates generated through our proprietary antibody program and our gene therapy and non-viral therapeutics platforms and programs. Research programs to identify new product candidates require substantial technical, financial and human resources. Most of our product candidates are in preclinical development, and one is in early-stage clinical trials. Our current portfolio of product candidates is subject to change as we continue to conduct preclinical and clinical testing and to develop product candidates and prioritize or abandon product candidates based on such results and other factors. For example, we are no longer advancing VY9323, formerly the lead development candidate for our SOD1 silencing program for ALS, as a development candidate based on three-month data from a non-human primate GLP toxicology study suggesting that a different payload would be necessary to achieve the desired product profile for the program. We may also fail to identify other product candidates for clinical development for several reasons. For example, our research may be unsuccessful in identifying potential product candidates or our potential product candidates may be shown to have harmful side effects, may be commercially impracticable to manufacture or may have other characteristics that may make the products unmarketable or unlikely to receive marketing approval. 85 Table of Contents Additionally, because we have limited resources, we may forego or delay pursuit of opportunities with certain programs or product candidates or for indications that later prove to have greater commercial potential. For example, we paused investment in our apolipoprotein E gene therapy program to prioritize other programs. Furthermore, similar to our prior investments with regard to our VY-AADC (NBIb-1817) and VY-HTT01 programs, our spending on current and future research and development programs may not yield any commercially viable products. If we do not accurately evaluate the commercial potential for a particular product candidate, we may relinquish valuable rights to that product candidate through strategic collaboration, option and license, or other arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate. Alternatively, we may allocate internal resources to a product candidate in a therapeutic area in which it would have been more advantageous to enter into a licensing or collaboration arrangement. Several of our current preclinical programs have previously been part of collaborations with third parties. While we have invested significant resources in these programs, we may decide in the future to cease development activities on one or more of them. If any of these events occur, we may be forced to abandon our development efforts with respect to a particular product candidate or fail to develop a potentially successful product candidate, which could harm our business, financial condition, results of operations and prospects. Our future success depends on our ability to retain key members of our management and research and development teams, and to attract, retain and motivate qualified personnel. We are highly dependent on the management, technical, and scientific expertise of principal members of our management, scientific, and clinical teams. While we have entered into employment agreements or offer letters with each of our executive officers, any of them could leave our employment at any time, as all of our employees are “at will” employees. We currently do not have “key person” insurance on any of our employees. The loss of the services of one or more of our current employees might impede the achievement of our research, development and commercialization objectives. Recruiting and retaining qualified employees, consultants and advisors for our business, including scientific and technical personnel, is critical to our success. There currently is a shortage of skilled individuals with substantial gene therapy experience, which is likely to continue. As a result, competition for skilled personnel, including in gene therapy research and vector manufacturing, is intense and the turnover rate can be high. We may not be able to attract and retain personnel on acceptable terms, if at all, given the competition among numerous pharmaceutical and biotechnology companies and academic institutions for individuals with similar skill sets. Our consultants and advisors may be employed by employers other than us and may have commitments under consulting or advisory contracts with other entities that may limit their availability to us. In addition, failure to succeed in preclinical or clinical trials or applications for marketing approval, the termination of relationships with collaborators, and the reduction of our workforce in connection with the development of a new portfolio and platform strategy may make it more challenging to recruit and retain qualified personnel. The inability to recruit, or loss of services of, certain executives, such as the recent departure of our Chief Medical Officer, key employees, consultants or advisors, may impede the progress of our research, development and commercialization objectives and could harm our business, financial condition, results of operations and prospects. In 2025 and 2026, we reduced the size of our organization in connection with restructurings. We may encounter difficulties in managing our business as a result of these restructurings, or as a result of the attrition that has occurred or may in the future occur due to these restructurings, which could disrupt our operations. In addition, we may not achieve anticipated benefits and savings from these restructurings. Our board of directors have approved restructuring plans to eliminate a portion of our workforce as part of initiatives to reduce expenses and enhance operations. The restructurings were approved in connection with our ongoing evaluation of our operations and our efforts to focus resources on creating shareholder value on critical program and platform development. The restructurings during 2025 and 2026 involved the termination of 71 employees, representing 41% of our workforce as of January 1, 2025. ​ 86 Table of Contents The continuing impact of the restructurings and additional measures we might take to reduce costs could divert management attention, yield attrition beyond our intended reduction in force, reduce employee morale, or cause us to delay, limit, reduce or eliminate certain product development plans. ​ If we are unable to manage expected growth in the scale and complexity of our operations, our performance may suffer. If we are successful in executing our business strategy, we will need to expand our managerial, operational, financial and other systems and resources to manage our operations, continue our research and development activities and, in the longer term, build a commercial infrastructure to support commercialization of any of our product candidates that are approved for sale. We can provide no assurances that we will have sufficient resources in the future to manage all of our planned programs. Future growth would impose significant added responsibilities on members of management, may lead to significant added costs, and may divert our management and business development resources. It is likely that our management, finance, development personnel, systems and facilities currently in place may not be adequate to support this future growth. Our need to effectively manage our operations, growth and product candidates requires that we continue to develop more robust business processes and improve our systems and procedures in each of these areas and to attract and retain sufficient numbers of talented employees. We may be unable to successfully implement these tasks on a larger scale and, accordingly, may not achieve our research, development and growth goals. Our employees, principal investigators, consultants and commercial partners may engage in misconduct or other improper activities, including non-compliance with regulatory standards and requirements and insider trading. We are exposed to the risk of fraud or other misconduct by our employees, principal investigators, consultants, collaborators, and commercial partners. Misconduct by these parties could include intentional failures to comply with FDA regulations or the regulations applicable in the European Union and other jurisdictions, provide accurate information to the FDA, the European Commission and other regulatory authorities, comply with healthcare fraud and abuse laws and regulations in the United States and abroad, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Such misconduct also could involve the improper use of information obtained in the course of clinical trials or interactions with the FDA or other regulatory authorities, which could result in regulatory sanctions and cause serious harm to our reputation. We have adopted a code of conduct applicable to all of our employees, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from government investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, financial condition, results of operations and prospects, including the imposition of significant fines or other sanctions. Current and future legislation may increase the difficulty and cost for us and any collaborators to obtain marketing approval of and commercialize our product candidates and affect the prices we, or they, may obtain. In the United States and foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our ability, or the ability of any collaborators, to profitably sell any products for which we obtain marketing approval. We expect that current laws, as well as other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we, or any collaborators, may receive for any approved products. If reimbursement of our products is unavailable or limited in scope, our business could be materially harmed. In March 2010, President Obama signed the ACA into law. In addition, other legislative changes have been proposed and adopted since the ACA was enacted. In August 2011, the Budget Control Act of 2011, among other things, 87 Table of Contents created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2013 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs. These changes included aggregate reductions to Medicare payments to providers of up to 2% per fiscal year, which went into effect in April 2013 and will remain in effect through 2032 under the Coronavirus Aid, Relief, and Economic Security Act, or the CARES Act. The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. These laws may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices we may obtain for any of our product candidates for which we may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used. Since enactment of the ACA, there have been, and continue to be, numerous legal challenges and Congressional actions to repeal and replace provisions of the law. For example, with enactment of the Tax Cuts and Jobs Act of 2017, or the TCJA, which was signed by President Trump on December 22, 2017, Congress repealed the “individual mandate.” The repeal of this provision, which requires most Americans to carry a minimal level of health insurance, became effective in 2019. Further, in June 2021, the United States Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the statute. Litigation and legislation over the ACA are likely to continue, with unpredictable and uncertain results. During the first Trump Administration, the Congress and administration sought to overturn the ACA and related measures. Shortly after taking office in January 2025, President Trump revoked numerous executive orders issued by President Biden, including at least two executive orders (e.g., EO 14009, Strengthening Medicaid and the Affordable Care Act, and EO 14070, Continuing to Strengthen Americans’ Access to Affordable, Quality Health Coverage) where were designed to further implement the ACA. We anticipate similar efforts to undermine the ACA, and the accompanying uncertainty, for the foreseeable future. We expect that these healthcare reforms, as well as other healthcare reform measures that may be adopted in the future, may result in additional reductions in Medicare and other healthcare funding, more rigorous coverage criteria, new payment methodologies and additional downward pressure on the price that we receive for any approved product and/or the level of reimbursement physicians receive for administering any approved product we might bring to market. Reductions in reimbursement levels may negatively impact the prices we receive or the frequency with which our products are prescribed or administered. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors. Accordingly, such reforms, if enacted, could have an adverse effect on anticipated revenue from product candidates that we may successfully develop and for which we may obtain marketing approval and may affect our overall financial condition and ability to develop or commercialize product candidates. The prices of prescription pharmaceuticals in the United States and foreign jurisdictions are subject to considerable legislative and executive actions and could impact the prices we obtain for our drug products, if and when approved. The prices of prescription pharmaceuticals have also been the subject of considerable discussion in the United States and other jurisdictions. To date, there have been several U.S. congressional inquiries, as well as proposed and enacted state and federal legislation designed to, among other things, bring more transparency to pharmaceutical pricing, review the relationship between pricing and manufacturer patient programs, reduce the costs of pharmaceuticals under Medicare and Medicaid, and reform government program reimbursement methodologies for products. In addition, in October 2020, the Department of Health and Human Services, or the HHS, and the FDA published a final rule allowing states and other entities to develop a Section 804 Importation Program, or SIP, to import certain prescription drugs from Canada into the United States. That regulation was challenged in a lawsuit by the Pharmaceutical Research and Manufacturers of America, or PhRMA, but the case was dismissed by a federal district court in February 2023 after the court found that PhRMA did not have standing to sue HHS. Several states have passed laws allowing for the importation of drugs from Canada. On January 5, 2024, the FDA approved Florida’s plan for Canadian drug importation. That state now has authority to import certain drugs from Canada for a period of two years once certain conditions are met. Florida will first need to submit a pre-import request for each drug selected for 88 Table of Contents importation, which must be approved by the FDA. The state will also need to relabel the drugs and perform quality testing of the products to meet FDA standards. On May 21, 2025, the FDA announced that it would offer individual states the opportunity to submit a draft proposal for pre-review and meet with the FDA to obtain initial feedback from FDA prior to formally submitting their SIP proposals. The intent of these meetings is to assist states in developing their proposals by further clarifying requirements, enhancing the quality of proposals submitted to the agency and ultimately shortening the review timeline. Further, in November 2020, the HHS finalized a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The rule also creates a new safe harbor for price reductions reflected at the point-of-sale, as well as a safe harbor for certain fixed fee arrangements between pharmacy benefit managers and manufacturers. Pursuant to court order, the removal and addition of the aforementioned safe harbors were delayed, and recent legislation imposed a moratorium on implementation of the rule until January 1, 2026. The Inflation Reduction Act of 2022, or IRA, further delayed implementation of this rule to January 1, 2032. More recently, on August 16, 2022, the IRA was signed into law by President Biden. The new legislation has implications for Medicare Part D, which is a program available to individuals who are entitled to Medicare Part A or enrolled in Medicare Part B to give them the option of paying a monthly premium for outpatient prescription drug coverage. Among other things, the IRA requires manufacturers of certain drugs to engage in price negotiations with Medicare (beginning in 2026), with prices that can be negotiated subject to a cap; imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation; and replaces the Part D coverage gap discount program with a new discounting program. The IRA permits the Secretary of the HHS to implement many of these provisions through guidance, as opposed to regulation, for the initial years. Specifically, with respect to price negotiations, Congress authorized Medicare to negotiate lower prices for certain costly single-source drug and biologic products that do not have competing generics or biosimilars and are reimbursed under Medicare Part B and Part D. CMS may negotiate prices for ten high-cost drugs paid for by Medicare Part D starting in 2026, followed by 15 Part D drugs in 2027, 15 Part B or Part D drugs in 2028, and 20 Part B or Part D drugs in 2029 and beyond. This provision applies to drug products that have been approved for at least nine years and biologics that have been licensed for 13 years. Drugs and biologics that have been approved for a single rare disease or condition were originally categorically excluded from price negotiation. With the passage of the One Big Beautiful Bill Act on July 3, 2025, which was signed into law on July 4, 2025, Congress extended this exemption to drugs and biologics with multiple orphan drug designations. Nonetheless, since CMS may establish a maximum price for these products in price negotiations, we would be fully at risk of government action if our products became the subject of Medicare price negotiations. Moreover, given the risk that could be the case, these provisions of the IRA may also further heighten the risk that we would not be able to achieve the expected return on any drug products or full value of our patents protecting our products if prices are set after such products have been on the market for nine years. Further, the legislation subjects drug manufacturers to civil monetary penalties and a potential excise tax for failing to comply with the legislation by offering a price that is not equal to or less than the negotiated “maximum fair price” under the law or for taking price increases that exceed inflation. The IRA also established inflation rebate programs under Medicare Part B and Part D. These programs require manufacturers to pay rebates to Medicare if they raise their prices for certain Part B and Part D drugs faster than the rate of inflation. On December 9, 2024, with issuance of its 2025 Physician Fee Schedule final regulation, CMS finalized its rules governing the IRA inflation rebate programs. The new law also caps Medicare out-of-pocket drug costs at $2,000 a year. In addition, the IRA potentially raises legal risks with respect to individuals participating in a Medicare Part D prescription drug plan who may experience a gap in coverage if they required coverage above their initial annual coverage limit before they reached the higher threshold, or “catastrophic period” of the plan. Individuals requiring services exceeding the initial annual coverage limit and below the catastrophic period must pay 100% of the cost of their prescriptions until they reach the catastrophic period. Among other things, the IRA contains many provisions aimed at reducing this financial burden on individuals by reducing the co-insurance and co-payment costs, expanding eligibility for lower income subsidy plans, and price caps on annual out-of-pocket expenses, each of which could have potential pricing and reporting implications. ​ 89 Table of Contents The first cycle of negotiations for the Medicare Drug Price Negotiation Program commenced in the summer of 2023. On August 15, 2024, the HHS published the results of the first Medicare drug price negotiations for ten selected drugs that treat a range of conditions, including diabetes, chronic kidney disease, and rheumatoid arthritis. The prices of these ten drugs became effective January 1, 2026. On January 17, 2025, CMS announced its selection of 15 additional drugs covered by Part D for the second cycle of negotiations. Thereafter, following the change in administrations, CMS issued a public statement on January 29, 2025, declaring that lowering the cost of prescription drugs is a top priority of the new administration and CMS is committed to considering opportunities to bring greater transparency in the negotiation program. The second cycle