REGENXBIO Inc. 10-K

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of our financial condition and results of operations in conjunction with the audited financial statements and the notes thereto included elsewhere in this Annual Report on Form 10-K. In addition, you should read the “Risk Factors” and “Information Regarding Forward-Looking Statements” sections of this Annual Report on Form 10-K for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. For a full discussion and analysis of financial condition and results of operations for the year ended December 31, 2022, including a year-over-year comparison to the year ended December 31, 2021, please read the “Management's Discussion and Analysis of Financial Condition and Results of Operations” section of our Annual Report on Form 10-K for the year ended December 31, 2022, which we filed with the SEC on February 28, 2023. Overview We are a leading clinical-stage biotechnology company seeking to improve lives through the curative potential of gene therapy. Our investigational gene therapies are designed to deliver functional genes to address genetic defects in cells, enabling the production of therapeutic proteins or antibodies that are intended to impact disease. Through a single administration, gene therapy could potentially alter the course of disease significantly and deliver improved patient outcomes with long-lasting effects. Overview of Product Candidates We have developed a broad pipeline of gene therapy programs using our proprietary adeno-associated virus (AAV) gene therapy delivery platform (NAV Technology Platform) to address genetic diseases. Our programs and product candidates are described below: • ABBV-RGX-314: We are developing ABBV-RGX-314 in collaboration with AbbVie as a potential one-time treatment for wet age-related macular degeneration (wet AMD), diabetic retinopathy (DR) and other additional chronic retinal conditions which cause total or partial vision loss. ABBV-RGX-314 is currently being evaluated in nine ongoing clinical trials in the United States and Canada. Such ongoing clinical trials include two pivotal trials, one Phase II bridging study, one Long-term Follow-up study, and a Fellow Eye Treatment study in patients with wet AMD, all utilizing subretinal delivery, as well as two Phase II clinical trials in patients with wet AMD and DR are also ongoing along with two corresponding Long-term Follow-up studies, all utilizing in-office suprachoroidal delivery. ABBV-RGX-314 uses the NAV ® AAV8 vector to deliver a gene encoding a therapeutic antibody fragment to inhibit vascular endothelial growth factor (VEGF). We have licensed certain exclusive rights to the SCS Microinjector ® from Clearside Biomedical, Inc. (Clearside) to deliver gene therapy treatments to the suprachoroidal space of the eye. Enrollment continues to be on track in the ATMOSPHERE ® and ASCENT™ pivotal trials as well as the Fellow Eye treatment study for the treatment of patients with wet AMD using subretinal delivery. These trials are expected to support global regulatory submissions with the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in late 2025 through the first half of 2026. We are also evaluating the pharmacodynamics, safety and efficacy of ABBV-RGX-314 in patients with wet AMD using the subretinal delivery approach in a Phase II bridging study using Good Manufacturing Practices (cGMP) material produced by our NAVXpress™ bioreactor platform process. The AAVIATE ® trial is a multi-center, open label, randomized, controlled, dose-escalation Phase II trial to evaluate the efficacy, safety and tolerability of suprachoroidal delivery of ABBV-RGX-314 for the treatment of wet AMD. The ALTITUDE ® trial is a multi-center, open label, randomized, controlled, dose-escalation Phase II trial to evaluate the efficacy, safety and tolerability of ABBV-RGX-314 for the treatment of DR. • RGX-202: We are developing RGX-202 as an investigational one-time AAV therapeutic for the treatment of Duchenne muscular dystrophy (Duchenne), using the NAV AAV8 vector to deliver a transgene for a novel microdystrophin that includes the functional elements of the C-Terminal (CT) domain as well as a muscle-specific promoter to support a targeted therapy for improved resistance to muscle damage associated with Duchenne. AFFINITY DUCHENNE ™ is a multicenter, open-label dose evaluation and dose expansion clinical trial to evaluate the safety, tolerability and clinical efficacy of a one-time intravenous (IV) dose of RGX-202 in patients with Duchenne. In February 2024, we reported interim data from the trial, demonstrating that RGX-202 continued to be well tolerated with 66 Table of Contents no drug-related serious adverse events in five patients at dose levels 1 and 2. Initial biomarker data in three patients who completed three-month assessments indicate encouraging increases in expression of RGX-202 microdystrophin and reduction from baseline in serum creatinine kinase levels, supporting evidence of clinical improvement. We expect to make a pivotal dose determination in mid-2024. We expect to share initial strength and functional assessment data for both dose levels and the initiation of a pivotal trial in the second half of 2024. We plan to use RGX-202 microdystrophin expression as a surrogate endpoint to support a Biologics License Application (BLA) filing using the accelerated approval pathway. The AFFINITY BEYOND ™ trial, an observational screening study, is also active and recruiting patients. The primary objective is to evaluate the prevalence of AAV8 antibodies in patients with Duchenne up to 12 years of age. Information collected in this study may be used to identify potential participants for the AFFINITY DUCHENNE trial and potential future trials of RGX-202. • RGX-121: We are developing RGX-121 as an investigational one-time AAV therapeutic for the treatment of Mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome, using the NAV AAV9 vector to deliver the gene that encodes the iduronate-2-sulfatase enzyme. CAMPSIITE ® is a Phase I/II/III multi-center, open-label trial to evaluate the efficacy, safety, tolerability and pharmacodynamics of RGX-121 in patients with MPS II aged 4 months up to 5 years old. We continue to follow patients in the trial, and in February 2024, we reported that the pivotal phase of the CAMPSIITE trial achieved its primary endpoint. We plan to use levels of cerebrospinal fluid D2S6 as a surrogate endpoint for accelerated approval and we are completing remaining activities in order to support a BLA submission in the second half of 2024. We believe that RGX-121 is likely to be eligible for priority review, especially if no other gene therapy product for MPS II is approved before submission of a BLA for RGX-121, and potential approval of the Company's planned BLA for RGX-121 could result in receipt of a Rare Pediatric Disease Priority Review Voucher in 2025, assuming the statutory criteria are met. Strategic Pipeline Prioritization and Restructuring In November 2023, we implemented a strategic pipeline prioritization and corporate restructuring designed to prioritize the development of ABBV-RGX-314, RGX-202 and RGX-121. Further, we will be seeking strategic alternatives, including potential partnering, for our other clinical stage product candidates: (i) RGX-111 for the treatment of Mucopolysaccharidosis Type I (MPS I), (ii) RGX-181 for the treatment of late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease, and (iii) RGX-381 for the treatment of the ocular manifestations of CLN2 disease. The restructuring plan included a reduction in workforce and other planned operating expenses, primarily in rare neurodegenerative disease development, early research and other general and administrative areas. We implemented a reduction in workforce of approximately 15%, which was substantially completed in the fourth quarter of 2023. For additional information regarding the corporate restructuring, please refer to Note 14, “Restructuring” to the accompanying audited consolidated financial statements. Overview of Our NAV Technology Platform In addition to our internal product development efforts, we also selectively license the NAV Technology Platform to other leading biotechnology and pharmaceutical companies, which we refer to as NAV Technology Licensees. As of December 31, 2023, our NAV Technology Platform was being applied in one commercial product (Zolgensma ® ), and the preclinical and clinical development of a number of other licensed products. Licensing the NAV Technology Platform allows us to maintain our internal product development focus on our core disease indications and therapeutic areas while still expanding the NAV gene therapy pipeline, developing a greater breadth of treatments for patients, providing additional technological and potential clinical proof-of-concept for our NAV Technology Platform and creating potential additional revenue. Financial Overview Revenues Our revenues to date consist primarily of license and royalty revenue resulting from the licensing of our NAV Technology Platform and other intellectual property rights. We have not generated any revenues from commercial sales of our own products. If we fail to complete the development of our product candidates in a timely manner or obtain regulatory approval and adequate labeling, our ability to generate future revenues will be materially compromised. We license our NAV Technology Platform and other intellectual property rights to other biotechnology and pharmaceutical companies, including collaborators for the joint development and commercialization of our product candidates. The terms of the 67 Table of Contents licenses vary, and licenses may be exclusive or non-exclusive and may be sublicensable by the licensee. Licenses may grant intellectual property rights for purposes of internal and preclinical research and development only, or may include the rights, or options to obtain future rights, to commercialize drug therapies for specific diseases using the NAV Technology Platform and other licensed rights. License agreements generally have a term at least equal to the life of the underlying patents, but are terminable at the option of the licensee. Consideration from licensees under our license agreements may include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products and (v) other consideration payable upon optional goods and services purchased by licensees. Future license and royalty revenues are dependent on the successful development and commercialization of licensed products, which is uncertain, and revenues may fluctuate significantly from period to period. Additionally, we may never receive consideration in our license agreements that is contemplated on option fees, development and sales-based milestone payments, royalties on sales of licensed products or sublicense fees, given the contingent nature of these payments. Our revenues are concentrated among a low number of licensees and licenses are terminable at the option of the licensee. The termination of our licenses by licensees may materially impact the amount of revenue we recognize in future periods. Please refer to Note 2 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K for a description of segment and geographical information regarding our revenues. Zolgensma Royalties Royalty revenue to date consists primarily of royalties on net sales of Zolgensma, which is marketed by Novartis Gene Therapies, Inc. (formerly AveXis, Inc.) (Novartis Gene Therapies), a wholly owned subsidiary of Novartis AG (Novartis), for the treatment of spinal muscular atrophy (SMA). Zolgensma is a licensed product under our license agreement with Novartis Gene Therapies for the development and commercialization of treatments for SMA using the NAV Technology Platform. Collaboration and License Agreement with AbbVie Effective in November 2021, we entered into a collaboration and license agreement with AbbVie Global Enterprises Ltd. (AbbVie), a subsidiary of AbbVie Inc., to jointly develop and commercialize ABBV-RGX-314 (the AbbVie Collaboration Agreement). We recognized license and royalty revenue of $370.0 million upon the effective date of the collaboration in November 2021. The AbbVie Collaboration Agreement may materially impact our future revenues, research and development expenses, other operating expenses and operating cash flows associated with the development and commercialization of ABBV-RGX-314. For additional information regarding the AbbVie Collaboration Agreement, please refer to Note 10, “License and Collaboration Agreements—AbbVie Collaboration and License Agreement” to the accompanying audited consolidated financial statements. Operating Expenses Our operating expenses consist primarily of cost of revenues, research and development expenses and general and administrative expenses. Personnel costs including salaries, wages, benefits, bonuses and stock-based compensation expense, comprise a significant component of research and development and general and administrative expenses. We allocate indirect expenses associated with our facilities, information technology costs, depreciation and other overhead costs between research and development and general and administrative categories based on employee headcount and the nature of work performed by each employee or using other reasonable allocation methodologies. Cost of Revenues Our cost of revenues consists primarily of upstream fees due to our licensors as a result of revenue generated from the licensing of our NAV Technology Platform and other intellectual property rights, including sublicense fees and royalties on net sales of licensed products. Sublicense fees are based on a percentage of license fees received by us from licensees and are recognized in the period that the underlying license revenue is recognized. Royalties are based on a percentage of net sales of licensed products by licensees and are recognized in the period that the underlying sales occur. Future costs of revenues are uncertain due to the nature of our license agreements and significant fluctuations in cost of revenues may occur from period to period. Research and Development Expense Our research and development expenses consist primarily of: • Salaries, wages and personnel-related costs, including benefits, travel and stock-based compensation, for our scientific personnel and others performing research and development activities; 68 Table of Contents • costs related to executing preclinical studies and clinical trials; • costs related to acquiring, developing and manufacturing materials for preclinical studies and clinical trials; • fees paid to consultants and other third parties who support our product candidate development; • other costs in seeking regulatory approval of our product candidates; and • direct costs and allocated costs related to laboratories and facilities, depreciation expense, information technology and other overhead. Up-front fees incurred in obtaining technology licenses for research and development activities, as well as associated milestone payments, are charged to research and development expense as incurred if the technology licensed has no alternative future use. We expect to continue to incur significant research and development expenses for the foreseeable future as we continue the development of our product candidates and engage in early research and development for prospective product candidates and new technologies. The following table summarizes our research and development expenses incurred during the years ended December 31, 2023, 2022 and 2021 (in thousands): Years Ended December 31, 2023 2022 2021 Direct Expenses ABBV-RGX-314 $ 23,512 $ 49,538 $ 26,084 RGX-202 10,426 16,863 8,215 RGX-121 18,606 8,198 9,062 Other product candidates 8,490 6,156 4,365 Total direct expenses 61,034 80,755 47,726 Unallocated Expenses Platform and new technologies 41,583 43,236 35,188 Personnel-related 95,112 90,383 76,979 Facilities and depreciation expense 28,842 22,820 18,918 Other unallocated 5,695 5,259 2,626 Total unallocated expenses 171,232 161,698 133,711 Total research and development $ 232,266 $ 242,453 $ 181,437 Direct expenses related to the development of ABBV-RGX-314 for the years ended December 31, 2023, 2022 and 2021 include $74.2 million, $19.3 million and $5.9 million, respectively, in net cost reimbursement from AbbVie under our eye care collaboration which were recorded as a reduction of research and development expenses. Net cost reimbursement from AbbVie includes reimbursement of personnel and overhead costs attributable to the development of ABBV-RGX-314, the underlying costs of which are reported as unallocated expenses in the table above. We typically utilize our employee and infrastructure resources across our development programs. In general, we do not allocate personnel and other internal costs, such as facilities and other overhead costs, to specific product candidates or development programs. Platform and new technologies reported in the table above include direct costs not identifiable with a specific lead product candidate, including costs associated with our research and development platform used across programs, process development, manufacturing analytics and early research and development for prospective product candidates and new technologies. Direct expenses related to the development of RGX-111, RGX-181 and RGX-381 are included in other product candidates in the table above. While we have discontinued internal development and are seeking strategic alternatives for these product candidates, we expect to continue to incur development expenses associated with long-term follow up studies for these product candidates. General and Administrative Expense Our general and administrative expenses consist primarily of salaries, wages and personnel-related costs, including benefits, travel and stock-based compensation, for employees performing functions other than research and development. This includes certain personnel in executive, commercial, corporate development, finance, legal, human resources, information technology, facilities and administrative support functions. Additionally, general and administrative expenses include facility-related and overhead costs not otherwise allocated to research and development expense, professional fees for accounting, legal, commercial and other advisory services, expenses associated with obtaining and maintaining patents, insurance costs, costs of our information systems and other 69 Table of Contents general corporate activities. We expect that our general and administrative expenses will continue to increase as we continue to develop, and potentially commercialize, our product candidates. Other Income (Expense) Interest Income from Licensing In accordance with our revenue recognition policy, interest income from licensing consists of imputed interest recognized from significant financing components identified in our license agreements with NAV Technology Licensees as well as interest income accrued on unpaid balances due from licensees. Investment Income Investment income consists of interest income earned and gains and losses realized from our cash equivalents, marketable securities and non-marketable equity securities. Cash equivalents are comprised of money market mutual funds and highly liquid debt securities with original maturities of 90 days or less at acquisition. Marketable securities are comprised of available-for-sale debt securities. Interest Expense Interest expense consists primarily of interest imputed on the liability related to the sale of future Zolgensma royalties to entities managed by Healthcare Royalty Management, LLC (collectively, HCR). Interest expense is recognized using the effective interest method, based on our estimate of total royalty payments expected to be received by HCR under the royalty purchase agreement. For further information regarding the royalty purchase agreement with HCR, please refer to Note 7, “Liability Related to Sale of Future Royalties” to the accompanying audited consolidated financial statements. Critical Accounting Policies and Estimates This Management’s Discussion and Analysis of Financial Condition and Results of Operations is based on our consolidated financial statements, which we have prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities for the periods presented. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities, and other reported amounts, that are not readily apparent from other sources. Actual results may differ materially from these estimates under different assumptions or conditions. Our significant accounting policies are fully described in Note 2 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. We believe the following accounting policies are critical to the process of making significant judgments and estimates in the preparation of our financial statements and understanding and evaluating our reported financial results. Revenue Recognition We recognize revenue in accordance with Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers (ASC 606). ASC 606 requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The following five steps are performed to determine the appropriate revenue recognition for arrangements within the scope of ASC 606: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies the performance obligations. We apply the five-step model to contracts that are within the scope of ASC 606 only when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer. At contract inception, for contracts within the scope of ASC 606, we assess the goods or services promised within each contract and determine those that are performance obligations and whether each promised good or service is distinct. We then recognize as revenue the amount of the transaction price that is allocated to respective performance obligations when (or as) the respective performance obligations are satisfied. 70 Table of Contents We evaluate our contracts with customers for the presence of significant financing components. If a significant financing component is identified in a contract and provides a financing benefit to the customer, the transaction price for the contract is adjusted to account for the financing portion of the arrangement, which is recognized as interest income over the financing term using the effective interest method. In determining the appropriate interest rates for significant financing components, we evaluate the credit profile of the customer and prevailing market interest rates and select an interest rate in which we believe would be charged to the customer in a separate financing arrangement over a similar financing term. License and royalty revenue We license our NAV Technology Platform and other intellectual property rights to other biotechnology and pharmaceutical companies. The terms of the licenses vary, and licenses may be exclusive or non-exclusive and may be sublicensable by the licensee. Licenses may grant intellectual property rights for purposes of internal and preclinical research and development only, or may include the rights, or options to obtain future rights, to commercialize drug therapies for specific diseases using our NAV Technology Platform and other licensed rights. License agreements generally have a term at least equal to the life of the underlying patents, but are terminable at the option of the licensee. Consideration payable to us under our license agreements may include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products and (v) other consideration payable upon optional goods and services purchased by licensees. Our license agreements are accounted for as contracts with customers within the scope of ASC 606, with the exception of transactions for which the counterparty is determined not to be a customer. At the inception of each license agreement, we determine the contract term for purposes of applying the requirements of ASC 606. Licenses are generally terminable at the option of the licensee with advance notice to us. For each license granted, including licenses granted upon the exercise of license options, we evaluate these termination rights to determine whether a substantive termination penalty would be incurred by the licensee upon termination. If the licensee incurs a substantive termination penalty upon termination, the contract term for revenue recognition purposes is generally equal to the stated term of the license, which is the life of the underlying licensed patents. Alternatively, if the licensee does not incur a substantive termination penalty upon termination, the contract term for revenue recognition purposes may be shorter than the stated term of the license, in which case the termination rights may be accounted for as contract renewal options. The determination of whether a substantive termination penalty is associated with the termination rights requires significant judgment. In making this determination, we consider, among other things, the nature of the intellectual property rights that would be returned to us upon termination, including the exclusivity of the licensed rights and the stage of development of the licensed products, the payment terms, including the amount and timing of non-refundable or guaranteed payments, and the business purpose of the termination rights granted to the licensee. Generally, the most significant judgment in determining whether a substantive termination penalty exists relates to the amount of any up-front or guaranteed non-refundable payments relative to the amount of annual payments that may be avoided by the licensee upon termination of the license. We consider all of the facts and circumstances relevant to each license when making this determination. Performance obligations under our license agreements may include (i) the delivery of intellectual property licenses, (ii) options granted to licensees to acquire additional licenses, to the extent the options represent material rights to the licensee, and (iii) research and development services to be performed by us related to licensed products. License agreements may provide licensees with contract renewal options or options to acquire additional licenses, goods or other services. Options are evaluated at the inception of the license agreement to determine whether they provide material rights to the licensee. In making this determination, we consider whether the options are priced at an incremental discount to the standalone selling price for the underlying licenses, goods or services, in which case the option is considered to be a material right to the licensee and is accounted for as a separate performance obligation under the current license agreement. At the inception of each license agreement which contains performance obligations for research and development services, we evaluate whether the license is distinct from the research and development services, which requires judgment. In making this determination, we consider, among other things, the stage of development of the licensed products and whether the research and development services will significantly impact further development of the licensed products. If it is determined that the license is not distinct from the research and development services, the license is combined with the research and development services into a single performance obligation. 71 Table of Contents We evaluate the transaction price of our license agreements at the inception of each agreement and at each reporting date. The transaction price includes the fixed consideration payable to us during the contract term, as well as any variable consideration to the extent that it is probable that a significant reversal of revenue will not occur in the future. Fixed consideration under the license agreements includes up-front and annual fees payable during the contract term. Variable consideration under the license agreements includes development and sales-based milestone payments, sublicense fees and royalties on sales of licensed products. Consideration contingent upon the exercise of options by a licensee is excluded from the transaction price and not accounted for as part of the license agreement until the option is exercised. The transaction price for each license agreement is allocated to the underlying performance obligations based on their relative standalone selling prices and recognized as revenue when (or as) the performance obligations are satisfied. Consideration allocated to performance obligations for the delivery of an intellectual property license is recognized as revenue in full upon the delivery of the license to the licensee. Consideration allocated to performance obligations for license options is recognized as revenue in full upon the earlier of the option exercise or expiration. The exercise of a license option by a licensee is accounted for as a new license for revenue recognition purposes. Consideration allocated to performance obligations for research and development services is recognized as revenue as the services are performed by us. Up-front and annual licenses fees payable to us over the contract term of each license are included in the transaction price, and the portion of this consideration allocated to the performance obligation for the delivery of the intellectual property license is recognized as revenue in full upon the delivery of the license to the licensee. If annual license fees are payable to us in periods beyond 12 months from the delivery of the license, a significant financing component is deemed to exist which provides a financing benefit to the licensee. If a significant financing component is identified, we adjust the transaction price for the license to include only the present value of the annual license fees payable to us over the contract term. The discounted portion of the license fees is recognized as interest income from licensing over the financing period of the license. Development milestone payments are payable to us upon the achievement of specified development milestones. At the inception of each license agreement that contains development milestone payments, we evaluate whether the milestones are considered probable of achievement and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal will not occur in the future, milestone payments are included in the transaction price and recognized as revenue upon the delivery of the license. Milestone payments contingent on the achievement of development milestones that are not within our control or the control of the licensee, such as regulatory approvals, are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved. At each reporting date, we re-evaluate the probability of achievement of each outstanding development milestone and, if necessary, adjust the transaction price for any milestones for which the probability of achievement has changed due to current facts and circumstances. Any such adjustments are recorded on a cumulative catch-up basis and recognized as revenue in the period of the adjustment. Royalties on sales of licensed products, sales-based milestone payments, including milestones payable upon first commercial sales of licensed products, and sublicense fees based on the receipt of certain fees by licensees from any sublicensees are excluded from the transaction price of each license and recognized as revenue in the period that the related sales or sublicenses occur, provided that the associated license has been delivered to the licensee. Royalty revenue to date consists primarily of royalties on net sales of Zolgensma, which is a licensed product under our license agreement with Novartis Gene Therapies for the development and commercialization of treatments for SMA. We recognize royalty revenue from net sales of Zolgensma in the period in which the underlying products are sold by Novartis Gene Therapies, which in certain cases may require us to estimate royalty revenue for periods of net sales which have not yet been reported to us. Estimated royalties are reconciled to actual amounts reported in subsequent periods, and any differences are recognized as an adjustment to royalty revenue in the period the royalties are reported. We receive payments from licensees based on the billing schedules established in each license agreement. Amounts recognized as revenue which have not yet been received from licensees, including unbilled royalties, are recorded as accounts receivable when our rights to the consideration are conditional solely upon the passage of time. Amounts recognized as revenue which have not yet been received from licensees are recorded as contract assets when our rights to the consideration are not unconditional. Contract assets are recorded as other current assets on the consolidated balance sheets. If a licensee elects to terminate a license prior to the end of the license term, the licensed intellectual property is returned to us and any consideration recorded as accounts receivable or contract assets which is not contractually payable by the licensee is charged off as a reduction of license revenue in the period of the termination. Amounts received by us prior to the delivery of underlying performance obligations are deferred and recognized as revenue upon the satisfaction of the performance obligations. Deferred revenue which is not expected to be recognized within 12 months from the reporting date is recorded as non-current on the consolidated balance sheets. 72 Table of Contents Collaborative Arrangements We evaluate our agreements with collaboration partners to determine whether they are within the scope of ASC 808, Collaborative Arrangements (ASC 808). Such arrangements are within the scope of ASC 808 if they involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This evaluation is performed throughout the life of the arrangement based on any changes in the roles and responsibilities of the parties under the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, we identify the various transactions with the counterparty and determine if any unit of account is more reflective of a transaction with a customer and therefore should be accounted for within the scope of ASC 606. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied. For transactions that are accounted for pursuant to ASC 606, we apply the five-step model as described in our revenue recognition policies. For additional information regarding our collaborative arrangements, including our ABBV-RGX-314 collaboration with AbbVie which became effective in November 2021, please refer to Note 10, “License and Collaboration Agreements” to the accompanying audited consolidated financial statements. Accrued Research and Development Expenses We estimate our accrued research and development expenses as of each balance sheet date. This process involves reviewing contracts and purchase orders with service providers, identifying services that have been performed on our behalf and estimating the level of service performed, the expected remaining period of performance and the associated expenses incurred for the service when we have not yet been invoiced or otherwise notified of actual cost. Depending on the timing of payments to the service providers and the estimated expenses incurred, we may record net prepaid or accrued research and development expenses relating to these costs. Examples of estimated accrued research and development expenses include fees paid to: • Contract research organizations (CROs) and other vendors in connection with preclinical development and clinical studies; • Contract manufacturing organizations (CMOs) and other vendors related to process development and manufacturing of materials for use in preclinical development and clinical studies; and • service providers for professional service fees such as consulting and other research and development related services. Our understanding of the status and timing of services performed relative to the actual status and timing may vary and may result in us reporting changes in estimates in any particular period. To date, there have been no material differences from our estimates to the amount actually incurred. Stock-based Compensation We account for our stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation (ASC 718). ASC 718 requires all stock-based awards to employees and nonemployees to be recognized as expense based on the grant date fair value of the awards. Our stock-based awards include stock options and restricted stock units granted to employees and nonemployees and shares issued to employees under our employee stock purchase plan. Our stock-based awards may be subject to either service or performance-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the estimated grant date fair value over the requisite service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the estimated grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable. We have elected to not estimate forfeitures of stock-based awards and account for forfeitures as they occur. We estimate the fair value of our stock option awards using the Black-Scholes option-pricing model, which requires the input of subjective assumptions, including (i) the fair value of the underlying common stock, (ii) the expected stock price volatility, (iii) the expected term of the award, (iv) the risk-free interest rate and (v) expected dividends. The fair value of our common stock, as used as an input to determine the fair value of our stock option awards, is based on the closing price of our common stock on the date of the grant. We estimate expected stock price volatility based on the historical volatility of our common stock over a period of time 73 Table of Contents commensurate with the expected term of our stock option awards. Due to the lack of sufficient historical data, we estimate the expected term of our employee stock options using the “simplified” method, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. For stock options granted to nonemployees, we use the contractual term of the award rather than expected term to estimate the fair value of the award. We estimate the risk-free interest rates for periods within the expected term of its options based on the rates of U.S. Treasury securities with maturity dates commensurate with the expected term of the associated awards. We assume a dividend yield of zero for our common stock as we have never paid dividends and do not expect to pay dividends for the foreseeable future. We estimate the fair value of our restricted stock units based on the closing price of our common stock on the date of the grant. Interest Expense on Liability Related to Sale of Future Royalties We recorded a liability for the net proceeds received from the sale of our Zolgensma royalty payments to HCR. The liability is amortized over the estimated life of the arrangement using the effective interest method. The total amount of royalty payments received by HCR under the agreement, less the net proceeds we received from the sale, is recorded as interest expense over the life of the arrangement. We estimate the effective interest rate based on our estimate of total future royalty payments to be received by HCR under the agreement. We reassess these estimates at each reporting date and adjust the effective interest rate and amortization of the liability on a prospective basis as necessary. Income Taxes We account for income taxes in accordance with ASC 740, Income Taxes, which provides for deferred taxes using an asset and liability approach. We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. As of December 31, 2023, we had federal net operating loss (NOL) carryforwards of $212.7 million, U.S. state NOL carryforwards of $259.1 million and federal and state research and development tax credit carryforwards of $77.3 million (net of unrecognized tax benefits of $0.1 million) which may be available to offset future income tax liabilities. Our federal NOL carryforwards and a portion of our state NOL carryforwards as of December 31, 2023 may be carried forward indefinitely. The remaining portion of our state NOL carryforwards and our federal and state credit carryforwards as of December 31, 2023 expire at various dates between 2029 and 2043. We have evaluated the positive and negative evidence bearing upon the realizability of our deferred tax assets, including our NOL and credit carryforwards. Based on our history of operating losses, and other relevant facts and circumstances, we concluded that it is more likely than not that the benefit of our deferred tax assets will not be realized. Accordingly, we provided a full valuation allowance for our net deferred tax assets as of December 31, 2023 and 2022. 74 Table of Contents Results of Operations Our consolidated results of operations were as follows (in thousands): Years Ended December 31, Change 2023 2022 2021 2023 vs. 2022 2022 vs. 2021 Revenues License and royalty revenue $ 90,242 $ 112,724 $ 470,347 $ (22,482 ) $ (357,623 ) Total revenues 90,242 112,724 470,347 (22,482 ) (357,623 ) Operating Expenses Cost of revenues 37,213 54,545 51,833 (17,332 ) 2,712 Research and development 232,266 242,453 181,437 (10,187 ) 61,016 General and administrative 88,494 85,281 79,333 3,213 5,948 Credit losses (recoveries) — — (2,569 ) — 2,569 Other operating expenses (income) 397 (6,679 ) 333 7,076 (7,012 ) Total operating expenses 358,370 375,600 310,367 (17,230 ) 65,233 Income (loss) from operations (268,128 ) (262,876 ) 159,980 (5,252 ) (422,856 ) Other Income (Expense) Interest income from licensing 25 342 719 (317 ) (377 ) Investment income 11,319 5,383 6,825 5,936 (1,442 ) Interest expense (6,862 ) (23,254 ) (26,277 ) 16,392 3,023 Total other income (expense) 4,482 (17,529 ) (18,733 ) 22,011 1,204 Income (loss) before income taxes (263,646 ) (280,405 ) 141,247 16,759 (421,652 ) Income Tax Benefit (Expense) 152 84 (13,407 ) 68 13,491 Net income (loss) $ (263,494 ) $ (280,321 ) $ 127,840 $ 16,827 $ (408,161 ) Comparison of the Years Ended December 31, 2023 and 2022 License and Royalty Revenue. License and royalty revenue decreased by $22.5 million, from $112.7 million for the year ended December 31, 2022 to $90.2 million for the year ended December 31, 2023. The decrease was primarily attributable to Zolgensma royalty revenues, which decreased by $16.6 million, from $101.9 million in 2022 to $85.3 million in 2023. As reported by Novartis, sales of Zolgensma in 2023 decreased by 11% (USD) as compared to 2022, and established markets are now treating mainly incident patients. Cost of Revenues. Cost of revenues decreased by $17.3 million, from $54.5 million for the year ended December 31, 2022 to $37.2 million for the year ended December 31, 2023. The decrease was largely attributable to a non-recurring charge of $9.2 million recognized in the first quarter of 2022 related to the amendment of our license agreement with The Trustees of the University of Pennsylvania (Penn) to buy out our obligation to pay sublicense fees to Penn under the license agreement. The remaining decrease in cost of revenues was primarily attributable to a reduction in upstream royalties payable to licensors on net sales of Zolgensma during the period. Research and Development Expense. Research and development expenses decreased by $10.2 million, from $242.5 million for the year ended December 31, 2022 to $232.3 million for the year ended December 31, 2023. The decrease was primarily attributable to the following: • a decrease of $11.6 million in manufacturing expenses and other costs of clinical supply for our lead product candidates, largely driven by ABBV-RGX-314 and RGX-202 clinical supply; • a decrease of $8.4 million in costs associated with clinical trial and regulatory activities, largely driven by an increase in net development cost reimbursement from AbbVie under our ABBV-RGX-314 collaboration, and partially offset by increases in clinical trial expenses for RGX-121 and RGX-202; and • a decrease of $2.2 million in costs associated with preclinical activities and other early stage research and development. The decrease in research and development expenses was partially offset by the following: • an increase of $7.2 million in costs for laboratories and facilities used by research and development personnel, including a $4.4 million increase in depreciation expense allocated to research and development functions, largely driven by the activation of our cGMP facility in mid-2022; and 75 Table of Contents • an increase of $4.7 million in personnel-related costs for research and development personnel, net of a $0.8 million decrease in stock-based compensation expense, largely driven by $3.0 million in restructuring charges for employee severance and benefits recognized in the fourth quarter of 2023. The decrease in research and development expenses for ABBV-RGX-314 was largely driven by a shift in the development cost sharing arrangement under our collaboration with AbbVie beginning in 2023. In accordance with the AbbVie Collaboration Agreement, through December 31, 2022 we were responsible for development expenses related to certain ongoing clinical trials of ABBV-RGX-314 and the remaining ABBV-RGX-314 development expenses were shared with AbbVie. Beginning in 2023, AbbVie became responsible for the majority of all ABBV-RGX-314 development expenses. General and Administrative Expense. General and administrative expenses increased by $3.2 million, from $85.3 million for the year ended December 31, 2022 to $88.5 million for the year ended December 31, 2023. The increase was primarily attributable to personnel-related costs, professional fees for corporate advisory services and other corporate overhead expenses. Other Operating Expenses (Income). Other operating expenses were $0.4 million for the year ended December 31, 2023, as compared to other operating income of $6.7 million for the year ended December 31, 2022. The change was primarily attributable to proceeds of $7.5 million received under a settlement agreement with a third party in the fourth quarter of 2022 that released certain claims regarding infringement of the Company's intellectual property. Investment Income . Investment income increased by $5.9 million, from $5.4 million for the year ended December 31, 2022 to $11.3 million for the year ended December 31, 2023. The increase was largely attributable to a realized gain of $2.2 million recognized in 2023 upon the achievement of milestones associated with the acquisition of our non-marketable equity securities of Corlieve Therapeutics SAS (Corlieve) by uniQure N.V. (uniQure) in July 2021. The remaining increase was primarily attributable to higher yields on investments in cash equivalents and marketable debt securities. Interest Expense . Interest expense decreased by $16.4 million, from $23.3 million for the year ended December 31, 2022 to $6.9 million for the year ended December 31, 2023. The decrease was primarily attributable to a lower balance in our liability related to the sale of future royalties resulting from Zolgensma royalties paid to HCR, as well as changes in the effective interest rate of the liability resulting from changes in the estimated royalties forecasted to be paid to HCR over the life of the royalty purchase agreement. Liquidity and Capital Resources Sources of Liquidity As of December 31, 2023, we had cash, cash equivalents and marketable securities of $314.1 million, which were primarily derived from the sale of our common stock and license fees received under the AbbVie Collaboration Agreement. We expect that our cash, cash equivalents and marketable securities as of December 31, 2023, will enable us to fund our operating expenses and capital expenditure requirements, and are sufficient to meet our financial commitments and obligations, for at least the next 12 months from the date of this report, based on our current business plan. Our recent sources of liquidity include the following events and transactions: • Effective in November 2021, we entered into the AbbVie Collaboration Agreement for the development and commercialization of ABBV-RGX-314. Pursuant to the AbbVie Collaboration Agreement, we received an up-front fee of $370.0 million from AbbVie upon the effective date of the agreement in November 2021, and we are eligible to receive up to $1.38 billion from AbbVie upon the achievement of specified development and sales-based milestones. Additionally, the parties will share equally in the net profits and net losses associated with the commercialization of ABBV-RGX-314 in the United States, and we are eligible to receive tiered royalties on net sales by AbbVie of ABBV-RGX-314 outside the United States. • In January 2021, we completed a public offering of 4,899,000 shares of our common stock (inclusive of 639,000 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares) at a price of $47.00 per share. The aggregate net proceeds from the offering, inclusive of the underwriters’ option exercise, were $216.1 million, net of underwriting discounts and commissions and offering expenses payable by us. We intend to devote the majority of our current capital to preclinical research, clinical development, seeking regulatory approval of our product candidates and, if approved, commercialization of our product candidates, as well as additional capital expenditures needed to support these activities. Because of the numerous risks and uncertainties associated with the development and commercialization of gene therapy product candidates, we are unable to estimate the total amount of operating expenditures and capital outlays necessary to complete the development of our product candidates. While we expect the pipeline prioritization and 76 Table of Contents corporate restructuring implemented in November 2023 to result in cost savings, we may also incur other charges or cash expenditures not currently contemplated due to events that may occur as a result of, or associated with, the restructuring. In addition, we may not achieve the expected benefits of any cost reduction measures on our currently anticipated timeline, or at all. Furthermore, our estimates are based on assumptions that may prove to be wrong, and we may use our available capital resources sooner than we currently expect which could accelerate our liquidity needs. At-the-Market Offering Program On September 1, 2023, we entered into an ATM Equity Offering SM Sales Agreement with BofA Securities, Inc. (BofA) pursuant to which we may offer and sell shares of our common stock having an aggregate offering price of up to $150.0 million from time to time through BofA, acting as our sales agent (the ATM Program). We intend to use proceeds obtained from the sale of shares under the ATM Program, if any, for general corporate purposes. As of December 31, 2023, no shares of common stock had been sold under the ATM Program. Private Placement On July 7, 2023, we sold 257,466 shares of our common stock in a private placement transaction for which we received aggregate net proceeds of $4.9 million, net of offering expenses. Cash Flows Our consolidated cash flows were as follows (in thousands): Years Ended December 31, 2023 2022 2021 Net cash provided by (used in) operating activities $ (218,407 ) $ (207,488 ) $ 218,875 Net cash provided by (used in) investing activities 190,943 (11,929 ) (406,642 ) Net cash provided by (used in) financing activities (34,966 ) (28,840 ) 195,250 Net increase (decrease) in cash and cash equivalents and restricted cash $ (62,430 ) $ (248,257 ) $ 7,483 Cash Flows from Operating Activities Our net cash used in operating activities for the year ended December 31, 2023 increased by $10.9 million from the year ended December 31, 2022. We expect to continue to incur regular net cash outflows from operations for the foreseeable future as we continue the development and advancement of our product candidates and other research programs. For the year ended December 31, 2023, our net cash used in operating activities of $218.4 million consisted of a net loss of $263.5 million and unfavorable changes in operating assets and liabilities of $10.9 million, offset by adjustments for non-cash items of $56.0 million. The changes in operating assets and liabilities include an increase in other current assets of $10.5 million, which was driven primarily by an increase in net cost reimbursement due from AbbVie under our ABBV-RGX-314 collaboration. Other changes in operating assets and liabilities occurred in the normal course of business as a result of changes in operating working capital. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $40.3 million and depreciation and amortization expense of $17.3 million. For the year ended December 31, 2022, our net cash used in operating activities of $207.5 million consisted of a net loss of $280.3 million, offset by adjustments for non-cash items of $58.9 million and favorable changes in operating assets and liabilities of $14.0 million. Adjustments for non-cash items primarily consisted of stock-based compensation expense of $40.8 million and depreciation and amortization expense of $12.9 million. The changes in operating assets and liabilities include an increase in other liabilities of $8.1 million, which was driven primarily by a long-term liability recorded during the period related to the amendment of the Penn License in the first quarter of 2022. The favorable changes in operating assets and liabilities were partially offset by a net decrease in total accounts payable and accrued expenses and other current liabilities of $6.8 million, which was driven primarily by decreases in accrued sublicense fees and royalties and income taxes payable. Other changes in operating assets and liabilities occurred in the normal course of business as a result of changes in operating working capital. Cash Flows from Investing Activities For the year ended December 31, 2023, our net cash provided by investing activities consisted of $285.5 million in maturities of marketable debt securities and $2.0 million in proceeds received from uniQure upon the achievement of milestones associated with their acquisition of Corlieve, offset by $86.6 million to purchase marketable debt securities and $10.0 million to purchase property and equipment. 77 Table of Contents For the year ended December 31, 2022, our net cash used in investing activities primarily consisted of $184.9 million to purchase marketable debt securities and $30.7 million to purchase property and equipment, partially offset by $203.1 million in maturities of marketable debt securities. Cash Flows from Financing Activities For the year ended December 31, 2023, our net cash used in financing activities primarily consisted of $42.3 million of Zolgensma royalties paid to HCR, net of imputed interest, under our royalty purchase agreement. Our net cash used in financing activities was partially offset by $4.9 million in net proceeds received from a private placement of our common stock in July 2023 and $3.3 million in proceeds received from the exercise of stock options and issuance of common stock under our employee stock purchase plan. For the year ended December 31, 2022, our net cash used in financing activities primarily consisted of $33.1 million of Zolgensma royalties paid to HCR, net of imputed interest, under our royalty purchase agreement, and was partially offset by $4.5 million in proceeds received from the exercise of stock options and issuance of common stock under our employee stock purchase plan. Additional Capital Requirements Our material capital requirements from known contractual and other obligations primarily relate to vendor service contracts and purchase commitments, in-license agreements, operating lease agreements and our Zolgensma royalty purchase agreement with HCR. In the normal course of business, we enter into services agreements with CROs, CMOs and other third parties. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of the services to be provided. Obligations to licensors under our in-license agreements may include sublicense fees, milestones fees, royalties and reimbursement of patent maintenance costs. Sublicense fees are payable to licensors when we sublicense underlying intellectual property to third parties; the fees are based on a percentage of the license fees we receive from sublicensees. Milestone fees are payable to licensors upon our future achievement of certain development, regulatory and commercial milestones. Royalties are payable to licensors based on a percentage of net sales of licensed products. Patent maintenance costs are payable to licensors as reimbursement for the cost of maintaining licensed patents. Due to the contingent nature of the payments, the amounts and timing of payments to licensors under our in-license agreements are uncertain and may fluctuate significantly from period to period. In March 2022, we entered into a letter agreement with Penn to buy out our obligation to pay sublicense fees under the Penn License. Pursuant to the letter agreement, we are obligated to pay Penn a total of $12.0 million to satisfy any other past or future obligations to pay sublicense fees under the Penn License, which is payable in four equal annual installments of $3.0 million beginning in March 2023. We are no longer obligated to pay sublicense fees to Penn under the license agreement, but remain obligated to pay Penn royalties on net sales of licensed products, milestone fees and reimbursement of certain patent maintenance costs in accordance with the Penn License. We have entered into a number of long-term operating leases for office, laboratory and manufacturing space in Rockville, Maryland, Washington, D.C. and New York, New York, as well as a number of laboratory and other equipment leases. Please refer to Note 6 to the accompanying consolidated financial statements for further information regarding our lease commitments. Under the terms of our royalty purchase agreement with HCR, our future Zolgensma royalties, less amounts payable by us to certain licensors, will be payable to HCR up to a specified capped amount. As of December 31, 2023, the total amount of future Zolgensma royalties to be paid to HCR under the agreement was $102.0 million if paid by November 7, 2024, or $142.0 million if paid after that date. We have no obligation to repay any amounts to HCR if total future Zolgensma royalty payments are not sufficient to repay these amounts. Future Funding Requirements We have incurred cumulative losses since our inception and had an accumulated deficit of $705.0 million as of December 31, 2023. Our transition to recurring profitability is dependent upon achieving a level of revenues adequate to support our cost structure, which depends heavily on the successful development, approval and commercialization of our product candidates. We do not expect to achieve such revenues, and expect to continue to incur losses, for at least the next several years. We expect to continue to incur 78 Table of Contents significant research and development and general and administrative expenses for the foreseeable future as we continue the development of, and seek regulatory approval for, our product candidates. Subject to obtaining regulatory approval for our product candidates, we expect to incur significant commercialization expenses for product sales, marketing, manufacturing and distribution. Additionally, we expect to continue to incur capital expenditures associated with building out additional laboratory and manufacturing capacity to further support the development of our product candidates and potential commercialization efforts. As a result, we will need significant additional capital to fund our operations, which we may obtain through one or more equity offerings, debt financings or other third-party funding, including potential strategic alliances and licensing or collaboration arrangements. Our future capital requirements will depend on many factors, including: • the timing of enrollment, commencement and completion of our clinical trials; • the results of our clinical trials; • the results of our preclinical studies for our product candidates and any subsequent clinical trials; • the scope, progress, results and costs of drug discovery, laboratory testing, preclinical development and clinical trials for our product candidates; • the costs associated with building out additional laboratory and manufacturing capacity; • the costs, timing and outcome of regulatory review of our product candidates; • the costs of future product sales, medical affairs, marketing, manufacturing and distribution activities for any of our product candidates for which we receive marketing approval; • revenue, if any, received from commercial sales of our products, should any of our product candidates receive marketing approval; • revenue received from commercial sales of Zolgensma and the timing and amount of Zolgensma royalties paid to HCR under our royalty purchase agreement; • revenue received from other commercial sales of our licensees’ and collaborators’ products, should any of their product candidates receive marketing approval, and other revenue received under our licensing agreements and collaborations; • the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending any intellectual property-related claims; • our current licensing agreements or collaborations remaining in effect, including the AbbVie Collaboration Agreement, and our ability to timely achieve any milestones set forth in such agreements or collaborations; • our ability to establish and maintain additional licensing agreements or collaborations on favorable terms, if at all; and • the extent to which we acquire or in-license other product candidates and technologies. Many of these factors are outside of our control. Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain regulatory and marketing approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our product revenues, if any, and any commercial milestones or royalty payments under our licensing agreements, will be derived from or based on sales of products that may not be commercially available for many years, if at all. In addition, revenue from our NAV Technology Platform licensing is dependent in part on the clinical and commercial success of our licensing partners, including the commercialization of Zolgensma, and on maintaining our license agreements with our licensor partners, including GlaxoSmithKline LLC (GSK) and Penn. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. The issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our common stock to decline. Adequate additional financing may not be available to us on acceptable terms, or at all. We also could be required to seek funds through arrangements with partners or otherwise that may require us to relinquish rights to our intellectual property, our product candidates or otherwise agree to terms unfavorable to us. Off-Balance Sheet Arrangements We did not have any off-balance sheet arrangements during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the SEC. 79 Table of Contents ITEM 7A. QUANTITATIVE AND QUALITAT IVE DISCLOSURES ABOUT MARKET RISK Interest Rate Risk We are exposed to market risk related to changes in interest rates. Our primary exposure to interest rate risk results from the cash equivalents and marketable securities in our investment portfolio. Our primary objectives in managing our investment portfolio are to preserve principal, maintain proper liquidity to meet operating needs and maximize yields. At any time, significant changes in interest rates can affect the fair value of the investment portfolio and its interest earnings. Currently, we do not hedge these interest rate exposures. As of December 31, 2023 and 2022, we had cash, cash equivalents and marketable securities of $314.1 million and $565.2 million, respectively. Our cash equivalents and marketable securities as of December 31, 2023 consisted of money market mutual funds, U.S. government and agency securities, certificates of deposit and corporate bonds. If market interest rates were to increase immediately and uniformly by 100 basis points, or one percentage point, from levels at December 31, 2023, we estimate that the increase would have resulted in a hypothetical decline of $1.5 million in the net fair value of our interest-sensitive securities. A similar increase in market interest rates as of December 31, 2022 would have resulted in an estimated hypothetical decline of $4.0 million in the net fair value of our interest-sensitive securities as of December 31, 2022. Foreign Currency Exchange Rate Risk We are exposed to foreign currency exchange rate risk as a result of entering into transactions denominated in currencies other than U.S. dollars, primarily including euros and British pounds. All foreign currency transactions settle on the applicable spot exchange basis at the time such payments are made. Accordingly, an adverse movement in foreign exchange rates between the U.S. dollar and the aforementioned currencies could impact our results of operations and cash flows. Currently, we do not hedge these foreign currency exchange rate exposures. The effect of a hypothetical 10% change in foreign currency exchange rates applicable to our business would not materially harm our business, financial condition or results of operations. ITEM 8. FINANCIAL STATEMEN TS AND SUPPLEMENTARY DATA The financial statements and related financial statement schedules required to be filed are listed in the Index to Consolidated Financial Statements and are incorporated herein. ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOU NTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE None. ITEM 9A. CONTROL S AND PROCEDURES Conclusion Regarding the Effectiveness of Disclosure Controls and Procedures Our management, with the participation of our Chief Executive Officer and our Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2023. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the Exchange Act), means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2023, our disclosure controls and procedures were effective at a reasonable assurance level. 80 Table of Contents Management’s Report on Internal Control over Financial Reporting Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rules 13a-15(f) and 15d-15(f) promulgated under the Exchange Act as a process designed by, or under the supervision of, our principal executive and principal financial officers and effected by our Board of Directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that: • pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets; • provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors; and • provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on the financial statements. Under the supervision and with the participation of management, including our principal executive and financial officers, we assessed our internal control over financial reporting as of December 31, 2023, based on criteria for effective internal control over financial reporting established in Internal Control — Integrated Framework (2013), issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our management’s opinion, we have maintained effective internal control over financial reporting as of December 31, 2023, based on criteria established in the COSO 2013 framework. The effectiveness of our internal control over financial reporting as of December 31, 2023 has been audited by PricewaterhouseCoopers LLP, our independent registered public accounting firm, as stated in their report which accompanies our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. Changes in Internal Control over Financial Reporting There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the quarter ended December 31, 2023 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. Limitations on the Effectiveness of Controls Control systems, no matter how well conceived and operated, are designed to provide a reasonable, but not an absolute, level of assurance that the objectives of the control system are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, have been detected. Because of the inherent limitations in any control system, misstatements due to error or fraud may occur and not be detected. 81 Table of Contents ITEM 9B. OTHER INFORMATION Rule 10b5-1 Trading Plans The adoption or termination of contracts, instructions or written plans for the purchase or sale of our securities by our Section 16 officers and directors for the three months ended December 31, 2023, each of which is intended to satisfy the affirmative defense of Rule 10b5-1(c) (Rule 10b5-1 Plan), were as follows: Scheduled Expiration Rule 10b5-1 Trading Plan Aggregate # of or Provides for Securities to be Name Action (a) Date Adopted Termination Date Purchase/Sale Purchased/Sold (b) Patrick J. Christmas Termination 12/23/2022 12/27/2023 Sale 95,476 Executive Vice President, Chief Legal Officer Adoption 12/28/2023 12/31/2024 Sale 79,056 (a) Patrick J. Christmas' Rule 10b5-1 Plan was terminated on December 27, 2023, prior to its scheduled expiration date of December 31, 2024 (the 2023 Plan). Mr. Christmas terminated the 2023 Plan in order to amend certain terms, and thereafter entered into a new Rule 10b5-1 Plan on December 28, 2023 (the 2024 Plan) to reflect those amendments in the 2024 Plan. No sales occurred under the 2023 Plan prior to its termination. (b) The aggregate number of shares in this column includes shares that may be forfeited or withheld to satisfy exercise price and tax withholding obligations at the time of vesting. Other than as described above, during the three months ended December 31, 2023, none of our directors or Section 16 reporting officers adopted or terminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement (as such terms are defined in Item 408 of the SEC's Regulation S-K). ITEM 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS Not applicable. 82 Table of Contents PART III ITEM 10. DIRECTORS, EXECUTIVE OF FICERS AND CORPORATE GOVERNANCE The information required by this item will be included in our proxy statement for the 2024 annual meeting of stockholders to be filed with the SEC within 120 days of the fiscal year ended December 31, 2023 (2024 Proxy Statement) under the headings “Election of Directors,” “Information about our Executive Officers” and “Corporate Governance” and is incorporated herein by reference. We maintain a code of business conduct and ethics that qualifies as a “code of ethics” under Item 406 of the SEC’s Regulation S-K and applies to each of our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer and controller, or persons performing similar functions. The code of business conduct and ethics is available in the corporate governance section of our corporate website at www.regenxbio.com. Any amendment or waiver of the “code of ethics” provisions of the code of business conduct and ethics for an executive officer or director may be granted only by our Board of Directors or a committee thereof and must be timely disclosed as required by applicable law. We intend to satisfy the disclosure requirements regarding any such amendment or waiver applicable to any principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, in a current report filed with the SEC on Form 8-K or on our corporate website at www.regenxbio.com. ITEM 11. EXECUTI VE COMPENSATION The information required by this item will be included in our 2024 Proxy Statement under the headings “Corporate Governance,” “Director Compensation” and “Executive Compensation” and is incorporated herein by reference. ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OW NERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS The information required by this item will be included in our 2024 Proxy Statement under the headings “Executive Compensation” and “Security Ownership of Certain Beneficial Owners and Management” and is incorporated herein by reference. ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE The information required by this item will be included in our 2024 Proxy Statement under the headings “Certain Relationships and Related Party Transactions” and “Corporate Governance” and is incorporated herein by reference. ITEM 14. PRINCIPAL ACCOU NTANT FEES AND SERVICES The information required by this item will be included in our 2024 Proxy Statement under the heading “Ratification of Appointment of Independent Registered Public Accounting Firm” and is incorporated herein by reference. 83 Table of Contents PART IV ITEM 15. EXHIBITS, FINAN CIAL STATEMENT SCHEDULES (a) The following documents are filed as part of, or incorporated by reference into, this Annual Report on Form 10-K: 1. Financial Statements. See Index to Consolidated Financial Statements under Item 8 of this Annual Report on Form 10-K. 2. Financial Statement Schedules. All schedules have been omitted because the information required to be presented in them is not applicable or is shown in the financial statements or related notes. 3. Exhibits. We have filed, or incorporated into this Annual Report on Form 10-K by reference, the exhibits listed on the accompanying Exhibit Index immediately following the financial statements in this Annual Report on Form 10-K. (b) Exhibits. See Item 15(a)(3) above. (c) Financial Statement Schedules. See Item 15(a)(2) above. ITEM 16. FORM 10-K SUMMARY Not applicable. 84 Table of Contents REGENXBIO INC. INDEX TO CONSOLIDATED FINANC IAL STATEMENTS Page Report of Independent Registered Public Accounting Firm (PCAOB ID: 238 ) 86 Consolidated Financial Statements: Consolidated Balance Sheets 88 Consolidated Statements of Operations and Comprehensive Income (Loss) 89 Consolidated Statements of Stockholders’ Equity 90 Consolidated Statements of Cash Flows 91 Notes to Consolidated Financial Statements 92 85 Table of Contents Report of Independent Re gistered Public Accounting Firm To the Board of Directors and Stockholders of REGENXBIO Inc. Opinions on the Financial Statements and Internal Control over Financial Reporting We have audited the accompanying consolidated balance sheets of REGENXBIO Inc. and its subsidiaries (the “Company”) as of December 31, 2023 and 2022, and the related consolidated statements of operations and comprehensive income (loss), of stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2023, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO. Basis for Opinions The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in Management’s Report on Internal Control over Financial Reporting appearing under Item 9A. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects. Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions. Definition and Limitations of Internal Control over Financial Reporting A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements. 86 Table of Contents Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Critical Audit Matters The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates. Revenue Recognition – Royalty Revenue As described in Notes 2 and 10 to the consolidated financial statements, the Company recognizes royalty revenue on sales of licensed products. The Company’s consolidated royalty revenue was $85.3 million for the year ended December 31, 2023. The principal consideration for our determination that performing procedures relating to royalty revenue recognition is a critical audit matter is a high degree of auditor effort in performing procedures related to the Company’s revenue recognition. Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls over the revenue recognition process. These procedures also included, among others, (i) obtaining and inspecting third party royalty reports and the related cash settlement, where applicable, (ii) testing the completeness and accuracy of data provided by management, and (iii) evaluating the financial statement presentation and related disclosures. /s/ PricewaterhouseCoopers LLP Washington, District of Columbia February 27, 2024 We have served as the Company’s auditor since 2015. 87 Table of Contents REGENXBIO INC. CONSOLIDATED BALANCE SHEETS (in thousands, except per share data) As of December 31, 2023 2022 Assets Current assets Cash and cash equivalents $ 34,522 $ 96,952 Marketable securities 240,736 267,690 Accounts receivable (net of allowance of $ 4,587 as of December 31, 2023) 24,790 28,082 Prepaid expenses 14,520 13,900 Other current assets 20,403 9,352 Total current assets 334,971 415,976 Marketable securities 38,871 200,560 Accounts receivable (net of allowance of $ 4,152 as of December 31, 2022) 701 1,504 Property and equipment, net 132,103 141,685 Operating lease right-of-use assets 60,487 65,116 Restricted cash 2,030 2,030 Other assets 4,807 6,397 Total assets $ 573,970 $ 833,268 Liabilities and Stockholders’ Equity Current liabilities Accounts payable $ 22,786 $ 27,213 Accrued expenses and other current liabilities 49,703 46,794 Deferred revenue 148 1,829 Operating lease liabilities 7,068 5,997 Liability related to sale of future royalties 50,567 48,601 Total current liabilities 130,272 130,434 Operating lease liabilities 82,222 88,802 Liability related to sale of future royalties 43,485 89,005 Other liabilities 6,249 8,832 Total liabilities 262,228 317,073 Commitments and contingencies (Note 8) Stockholders’ equity Preferred stock; $ 0.0001 par value; 10,000 shares authorized, no shares issued and outstanding at December 31, 2023 and 2022 — — Common stock; $ 0.0001 par value; 100,000 shares authorized at December 31, 2023 and 2022; 44,046 and 43,299 shares issued and outstanding at December 31, 2023 and 2022, respectively 4 4 Additional paid-in capital 1,021,214 973,145 Accumulated other comprehensive loss ( 4,429 ) ( 15,401 ) Accumulated deficit ( 705,047 ) ( 441,553 ) Total stockholders’ equity 311,742 516,195 Total liabilities and stockholders’ equity $ 573,970 $ 833,268 The accompanying notes are an integral part of these consolidated financial statements. 88 Table of Contents REGENXBIO INC. CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (in thousands, except per share data) Years Ended December 31, 2023 2022 2021 Revenues License and royalty revenue $ 90,242 $ 112,724 $ 470,347 Total revenues 90,242 112,724 470,347 Operating Expenses Cost of revenues 37,213 54,545 51,833 Research and development 232,266 242,453 181,437 General and administrative 88,494 85,281 79,333 Credit losses (recoveries) — — ( 2,569 ) Other operating expenses (income) 397 ( 6,679 ) 333 Total operating expenses 358,370 375,600 310,367 Income (loss) from operations ( 268,128 ) ( 262,876 ) 159,980 Other Income (Expense) Interest income from licensing 25 342 719 Investment income 11,319 5,383 6,825 Interest expense ( 6,862 ) ( 23,254 ) ( 26,277 ) Total other income (expense) 4,482 ( 17,529 ) ( 18,733 ) Income (loss) before income taxes ( 263,646 ) ( 280,405 ) 141,247 Income Tax Benefit (Expense) 152 84 ( 13,407 ) Net income (loss) $ ( 263,494 ) $ ( 280,321 ) $ 127,840 Other Comprehensive Income (Loss) Unrealized gain (loss) on available-for-sale securities, net 10,972 ( 12,832 ) ( 2,209 ) Total other comprehensive income (loss) 10,972 ( 12,832 ) ( 2,209 ) Comprehensive income (loss) $ ( 252,522 ) $ ( 293,153 ) $ 125,631 Net income (loss) per share: Basic $ ( 6.02 ) $ ( 6.50 ) $ 3.01 Diluted $ ( 6.02 ) $ ( 6.50 ) $ 2.91 Weighted-average common shares outstanding: Basic 43,734 43,152 42,438 Diluted 43,734 43,152 43,913 The accompanying notes are an integral part of these consolidated financial statements. 89 Table of Contents REGENXBIO INC. CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (in thousands) Accumulated Additional Other Total Common Stock Paid-in Comprehensive Accumulated Stockholders’ Shares Amount Capital Loss Deficit Equity Balances at December 31, 2020 37,476 $ 4 $ 667,181 $ ( 360 ) $ ( 289,072 ) $ 377,753 Issuance of common stock upon public offering, net of transaction costs of $ 14,194 4,899 — 216,059 — — 216,059 Exercise of stock options, net of tax 403 — 4,279 — — 4,279 Issuance of common stock under employee stock purchase plan 54 — 1,768 — — 1,768 Stock-based compensation expense — — 38,808 — — 38,808 Unrealized loss on available-for-sale securities, net — — — ( 2,209 ) — ( 2,209 ) Net income — — — — 127,840 127,840 Balances at December 31, 2021 42,831 4 928,095 ( 2,569 ) ( 161,232 ) 764,298 Vesting of restricted stock units, net of tax 60 — ( 284 ) — — ( 284 ) Exercise of stock options, net of tax 332 — 2,804 — — 2,804 Issuance of common stock under employee stock purchase plan 76 — 1,742 — — 1,742 Stock-based compensation expense — — 40,788 — — 40,788 Unrealized loss on available-for-sale securities, net — — — ( 12,832 ) — ( 12,832 ) Net loss — — — — ( 280,321 ) ( 280,321 ) Balances at December 31, 2022 43,299 4 973,145 ( 15,401 ) ( 441,553 ) 516,195 Vesting of restricted stock units, net of tax 164 — ( 419 ) — — ( 419 ) Exercise of stock options, net of tax 223 — 1,521 — — 1,521 Issuance of common stock under employee stock purchase plan 103 — 1,826 — — 1,826 Issuance of common stock upon private placement, net of transaction costs of $ 126 257 — 4,874 — — 4,874 Stock-based compensation expense — — 40,267 — — 40,267 Unrealized gain on available-for-sale securities, net — — — 10,972 — 10,972 Net loss — — — — ( 263,494 ) ( 263,494 ) Balances at December 31, 2023 44,046 $ 4 $ 1,021,214 $ ( 4,429 ) $ ( 705,047 ) $ 311,742 The accompanying notes are an integral part of these consolidated financial statements. 90 Table of Contents REGENXBIO INC. CONSOLIDATED STATEMENTS OF CASH FLOWS (in thousands) Years Ended December 31, 2023 2022 2021 Cash flows from operating activities Net income (loss) $ ( 263,494 ) $ ( 280,321 ) $ 127,840 Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities Stock-based compensation expense 40,267 40,788 38,808 Depreciation and amortization 17,320 12,909 9,564 Provision for credit losses (recoveries) — — ( 2,569 ) Net amortization of premiums on marketable debt securities 687 4,712 5,842 Net realized loss (gain) on investments ( 2,205 ) 79 ( 5,189 ) Non-cash interest expense ( 414 ) 137 4,642 Other non-cash adjustments 319 231 ( 281 ) Changes in operating assets and liabilities Accounts receivable 3,935 4,822 14,118 Prepaid expenses ( 620 ) 4,852 ( 8,247 ) Other current assets ( 10,546 ) 247 ( 7,314 ) Operating lease right-of-use assets 5,761 4,450 4,866 Other assets 1,590 31 ( 2,272 ) Accounts payable ( 2,791 ) 18,790 ( 2,304 ) Accrued expenses and other current liabilities 2,452 ( 25,616 ) 29,908 Deferred revenue ( 1,512 ) ( 1,165 ) ( 899 ) Operating lease liabilities ( 6,641 ) ( 544 ) 12,073 Other liabilities ( 2,515 ) 8,110 289 Net cash provided by (used in) operating activities ( 218,407 ) ( 207,488 ) 218,875 Cash flows from investing activities Purchases of marketable debt securities ( 86,564 ) ( 184,875 ) ( 498,144 ) Maturities of marketable debt securities 285,492 203,146 170,086 Sales of equity securities 1,975 524 5,591 Purchases of property and equipment ( 9,960 ) ( 30,724 ) ( 84,175 ) Net cash provided by (used in) investing activities 190,943 ( 11,929 ) ( 406,642 ) Cash flows from financing activities Proceeds from exercise of stock options 1,521 2,804 4,281 Taxes paid related to net settlement of stock-based awards ( 419 ) ( 284 ) ( 2 ) Proceeds from issuance of common stock under employee stock purchase plan 1,826 1,742 1,768 Proceeds from public offering of common stock, net of underwriting discounts and commissions — — 216,438 Proceeds from private placement of common stock, net of issuance costs 4,874 — — Offering expenses related to at-the-market offering program ( 470 ) — — Issuance costs for public offering of common stock — — ( 379 ) Transaction costs for sale of future royalties — — ( 265 ) Repayments under liability related to sale of future royalties, net of imputed interest ( 42,298 ) ( 33,102 ) ( 26,591 ) Net cash provided by (used in) financing activities ( 34,966 ) ( 28,840 ) 195,250 Net increase (decrease) in cash and cash equivalents and restricted cash ( 62,430 ) ( 248,257 ) 7,483 Cash and cash equivalents and restricted cash Beginning of period 98,982 347,239 339,756 End of period $ 36,552 $ 98,982 $ 347,239 Supplemental cash flow information Cash paid (received) for income taxes $ ( 142 ) $ 11,812 $ 5,996 Cash paid for imputed interest under liability related to sale of future royalties $ 7,276 $ 23,117 $ 21,635 The accompanying notes are an integral part of these consolidated financial statements. 91 Table of Contents REGENXBIO INC. NOTES TO CONSOLIDATED FINANC IAL STATEMENTS 1. Nature of Business REGENXBIO Inc. (the Company) is a clinical-stage biotechnology company seeking to improve lives through the curative potential of gene therapy. The Company's investigational gene therapies use adeno-associated virus (AAV) vectors from its proprietary gene delivery platform (NAV Technology Platform). The NAV® Technology Platform consists of exclusive rights to a large portfolio of AAV vectors, including commonly used AAV8 and AAV9. The Company has developed a broad pipeline of gene therapy product candidates using the NAV Technology Platform as a one-time treatment to address an array of diseases. In addition to its internal product development efforts, the Company also selectively licenses the NAV Technology Platform to other leading biotechnology and pharmaceutical companies (NAV Technology Licensees). As of December 31, 2023, the NAV Technology Platform was being applied by NAV Technology Licensees in one commercial product, Zolgensma®, and in the preclinical and clinical development of a number of other licensed products. Additionally, the Company has licensed intellectual property rights to collaborators for the joint development and commercialization of certain product candidates. The Company was formed in 2008 in the State of Delaware and is headquartered in Rockville, Maryland. The Company has incurred cumulative losses since inception and as of December 31, 2023, had generated an accumulated deficit of $ 705.0 million. The Company's ability to transition to recurring profitability is dependent upon achieving a level of revenues adequate to support its cost structure, which depends heavily on the successful development, approval and commercialization of its product candidates. The Company may never achieve recurring profitability, and unless and until it does, the Company will continue to need to raise additional capital. There is no assurance that the Company will be able to raise sufficient capital or obtain financing on favorable terms, or at all. As of December 31, 2023, the Company had cash, cash equivalents and marketable securities of $ 314.1 million, which management believes is sufficient to fund operations for at least the next 12 months from the date these consolidated financial statements were issued. 2. Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Foreign Currency Transactions The functional currency of the Company and its consolidated subsidiaries is the U.S. dollar. Transaction gains and losses that arise from exchange rate fluctuations on transactions denominated in currencies other than the U.S. dollar are included in results of operations as incurred. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities for the periods presented. Management bases its estimates on historical experience and various other factors that it believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities, and other reported amounts, that are not readily apparent from other sources. Actual results may differ materially from these estimates. Significant estimates are used in the following areas, among others: license and royalty revenue, the allowance for credit losses, accrued research and development expenses and other accrued liabilities, stock-based compensation expense, interest expense under the liability related to the sale of future royalties, income taxes and the fair value of financial instruments. Reclassifications Certain amounts reported in prior periods have been reclassified to conform to current period financial statement presentation. These reclassifications are not material and have no effect on previously reported financial position, results of operations and cash flows. 92 Table of Contents Segment and Geographical Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker (CODM), or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s CODM, its Chief Executive Officer, views the Company’s operations and manages the business as one operating segment. The Company’s revenues consist of license and royalty revenue. For the year ended December 31, 2023 , 32 % of the Company’s revenues were attributed to the U.S. and no other country accounted for 10 % or more of the Company’s revenues. For the year ended December 31, 2022 , 35 % and 10 % of the Company’s revenues were attributed to the U.S. and Germany, respectively, and no other countries accounted for 10 % or more of the Company’s revenues. For the year ended December 31, 2021 , 79 % and 7 % of the Company’s revenues were attributed to Bermuda and the U.S., respectively, and no other countries accounted for 10 % or more of the Company’s revenues. The country of origin for license revenue is determined based on the country of domicile of the licensee. The country of origin for royalty revenue is determined based on the location of the underlying net sales of licensed products. The substantial majority of the Company’s assets reside in the U.S. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. Restricted Cash Restricted cash includes money market mutual funds and other deposits used to collateralize irrevocable letters of credit required under the Company’s lease agreements and certain other agreements with third parties. The following table provides a reconciliation of cash and cash equivalents and restricted cash as reported on the consolidated balance sheets to the total of these amounts as reported at the end of the period in the consolidated statements of cash flows (in thousands): As of December 31, 2023 2022 2021 Cash and cash equivalents $ 34,522 $ 96,952 $ 345,209 Restricted cash 2,030 2,030 2,030 Total cash and cash equivalents and restricted cash $ 36,552 $ 98,982 $ 347,239 Marketable Securities Marketable securities consist of available-for-sale debt securities and are carried at fair value. Marketable debt securities with remaining maturity dates exceeding 12 months which are not intended to be sold prior to maturity for use in current operations are classified as non-current assets. Unrealized gains and losses on available-for-sale debt securities, net of any related tax effects, are excluded from results of operations and are included in other comprehensive income (loss) and reported as a separate component of stockholders’ equity until realized. The Company uses the aggregate portfolio approach to release the tax effects of unrealized gains and losses on available-for-sale debt securities in accumulated other comprehensive loss. Purchase premiums and discounts on marketable debt securities are amortized or accreted into the cost basis over the life of the related security as adjustments to the yield using the effective-interest method. Interest income is recognized when earned. Realized gains and losses from the sale or maturity of marketable securities are based on the specific identification method and are included in results of operations as investment income. At each reporting date, the Company evaluates available-for-sale debt securities which have an amortized cost basis in excess of the fair value of the security to determine if the unrealized loss or any potential credit losses should be recognized in results of operations. If the Company does not have the intent and ability to hold the security until recovery of the unrealized loss, the difference between the fair value and amortized cost basis of the security is charged to results of operations resulting in a new amortized cost basis of the security. If the Company has the intent and ability to hold the security until recovery of the unrealized loss, the security is evaluated for potential credit losses. If a credit loss is deemed to exist, the credit loss is recognized in results of operations and an allowance for credit losses is recorded against the amortized cost basis of the security. In determining whether a credit loss exists related to impaired available-for-sale debt securities, the Company considers, among other factors, the extent of the unrealized loss relative to the amortized cost basis, the credit rating of the issuer and any recent changes thereto, current and expected future economic conditions, and any adverse events or other changes in circumstances that have occurred which may indicate a potential credit loss. The Company did not record an allowance for credit losses on its available-for-sale debt securities as of December 31, 2023 or 2022. 93 Table of Contents Accounts Receivable Accounts receivable primarily consist of consideration due to the Company resulting from its license agreements with customers. Accounts receivable include amounts invoiced to licensees as well as rights to consideration which have not yet been invoiced, including unbilled royalties, and for which payment is conditional solely upon the passage of time. If a licensee elects to terminate a license prior to the end of the license term, the licensed intellectual property is returned to the Company and any accounts receivable from the licensee which are not contractually payable to the Company are charged off as a reduction of license revenue in the period of the termination. Accounts receivable which are not expected to be received by the Company within 12 months from the reporting date are stated net of a discount to present value and recorded as non-current assets on the consolidated balance sheets. The present value discount is recognized as a reduction of revenue in the period in which the accounts receivable are initially recorded and is accreted as interest income from licensing over the term of the receivables. Accounts receivable are stated net of an allowance for credit losses, if deemed necessary based on the Company’s evaluation of collectability and potential credit losses. Management assesses the collectability of its accounts receivable using the specific identification of account balances, and considers the credit quality and financial condition of its significant customers, historical information regarding credit losses and the Company’s evaluation of current and expected future economic conditions. If necessary, an allowance for credit losses is recorded against accounts receivable such that the carrying value of accounts receivable reflects the net amount expected to be collected. Accounts receivable balances are written off against the allowance for credit losses when the potential for collectability is considered remote. Please refer to Note 10 for further information regarding the allowance for credit losses related to accounts receivable. Concentrations of Credit Risk and Off-balance Sheet Risk Cash and cash equivalents, marketable debt securities and accounts receivable are financial instruments that are potentially subject to concentrations of credit risk. The Company’s cash and cash equivalents are deposited in accounts at multiple financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. The Company’s marketable debt securities consist of investment grade securities and may be subject to concentrations of credit risk. The Company has adopted an investment policy which limits potential concentrations of investments and establishes minimum acceptable credit ratings, thereby reducing credit risk exposure. With the exception of accounts receivable from Abeona Therapeutics Inc. (Abeona), as discussed further in Note 10, the Company believes that it is not exposed to significant credit risk related to accounts receivable due to the credit quality and history of collections from its significant customers, and the Company is unaware of any concentrations of credit risk related to accounts receivable from significant customers with deteriorated credit quality. The Company has no financial instruments with off-balance sheet risk of loss. The following table summarizes those customers who represented at least 10% of revenues or total net accounts receivable for the periods presented: Revenues Accounts Receivable, Net Years Ended December 31, As of December 31, 2023 2022 2021 2023 2022 Customer A 95 % 90 % 20 % 95 % 92 % Customer B * * 79 % * * * Represented less than 10% Leases The Company accounts for its lease arrangements in accordance with Accounting Standards Codification (ASC) 842, Leases (ASC 842). Under ASC 842, the Company classifies its leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the Company. Lease classification is evaluated at the inception of the lease agreement. Regardless of classification, the Company records a right-of-use asset and a lease liability for all leases with a term greater than 12 months. All of the Company’s leases as of December 31, 2023 and 2022 have been classified as operating leases. Operating lease expense is recognized on a straight-line basis over the term of the lease, with the exception of variable lease expenses which are recognized as incurred. The Company identifies leases in its contracts if the contract conveys the right to control the use of identified property, plant or equipment for a period of time in exchange for consideration. The Company does not allocate lease consideration between lease and nonlease components and records a lease liability equal to the present value of the remaining fixed consideration under the lease. The 94 Table of Contents interest rates implicit in the Company’s leases are generally not readily determinable. Accordingly, the Company uses its estimated incremental borrowing rate at the commencement date of the lease to determine the present value discount of the lease liability. The Company estimates its incremental borrowing rate for each lease based on an evaluation of its expected credit rating and the prevailing market rates for collateralized debt in a similar economic environment with similar payment terms and maturity dates commensurate with the term of the lease. The right-of-use asset for each lease is equal to the lease liability, adjusted for unamortized initial direct costs and lease incentives and prepaid or accrued rent. Initial direct costs of entering into a lease are included in the right-of-use asset and amortized as lease expense over the term of the lease. Lease incentives, such as tenant improvement allowances, are recorded as a reduction of the right-of-use asset and amortized as a reduction of lease expense over the term of the lease. The Company excludes options to extend or terminate leases from the calculation of the lease liability unless it is reasonably certain the option will be exercised. Property and Equipment Property and equipment is stated at cost less accumulated depreciation and amortization. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Estimated Useful Life Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory and manufacturing equipment 5 to 15 years Leasehold improvements Shorter of lease term or estimated useful life Cloud Computing Arrangements The Company capitalizes certain costs associated with the implementation of cloud computing arrangements that are accounted for as service contracts. Once implementation activities are substantially complete and the cloud-based application is ready for its intended use, capitalization ceases and amounts capitalized are amortized on a straight-line basis over the term of the hosting arrangement. Capitalized implementation costs for cloud-based applications and associated amortization are classified on the consolidated balance sheets and statements of operations and comprehensive income (loss) in the same manner as the costs of the associated hosting arrangement. As of December 31, 2023 and 2022, the Company had recorded capitalized costs, net of amounts amortized, of $ 1.0 million and $ 2.4 million, respectively, related to the implementation of cloud-based software applications, which were included in prepaid expenses and other assets on the consolidated balance sheets. Amortization of capitalized implementation costs for cloud-based applications recorded for the years ended December 31, 2023, 2022 and 2021 was $ 1.4 million, $ 1.3 million, and $ 0.6 million, respectively, and was included in general and administrative expenses in the consolidated statements of operations and comprehensive income (loss). Impairment of Long-lived Assets The Company evaluates its long-lived assets for impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to estimated future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. No material impairment losses on long-lived assets were recorded during the years ended December 31, 2023, 2022 and 2021 . Non-marketable Equity Securities Non-marketable equity securities consist of equity investments in other entities in which the Company’s ownership interest is below 20 % and the Company does not have significant influence over the operations of the entity, or for which the equity securities are not common stock or in-substance common stock. The Company’s non-marketable equity securities do not have readily determinable fair values and are measured at cost less impairment, adjusted for observable price changes for identical or similar investments of the same issuer. Please refer to Note 4 for further information on non-marketable equity securities. 95 Table of Contents Fair Value of Financial Instruments The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. ASC 820, Fair Value Measurements and Disclosures (ASC 820), establishes a hierarchy of inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: • Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. • Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The fair values of the Company’s Level 2 instruments are based on quoted market prices or broker or dealer quotations for similar assets. These investments are initially valued at the transaction price and subsequently valued utilizing third-party pricing providers or other market observable data. Please refer to Note 4 for further information on the fair value measurement of the Company’s financial instruments. Liability Related to Sale of Future Royalties As discussed in Note 7, the Company recorded a liability for the net proceeds received from the sale of its Zolgensma royalty payments to entities managed by Healthcare Royalty Management, LLC (collectively, HCR). The liability is accounted for as debt since the return to HCR is explicitly capped under the royalty purchase agreement, and is amortized over the estimated life of the arrangement using the effective interest method. The total amount of royalty payments received by HCR under the agreement, less the net proceeds received by the Company, is recorded as interest expense over the life of the arrangement. The Company estimates the effective interest rate based on its estimate of total royalty payments to be received by HCR under the agreement. The Company reassesses these estimates at each reporting date and adjusts the effective interest rate and amortization of the liability on a prospective basis as necessary. Due to its continuing involvement in the underlying license agreement with Novartis Gene Therapies, Inc. (formerly AveXis, Inc.) (Novartis Gene Therapies), the Company continues to recognize royalty revenue on net sales of Zolgensma and records the royalty payments to HCR as a reduction of the liability when paid. As such payments are made to HCR, the balance of the liability will be effectively repaid over the life of the royalty purchase agreement. The portion of the liability related to the sale of future royalties which is expected to be amortized within 12 months of the reporting date is recorded as a current liability, with the remaining portion of the liability recorded as a non-current liability. Revenue Recognition The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (ASC 606). ASC 606 requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The following five steps are performed to determine the appropriate revenue recognition for arrangements within the scope of ASC 606: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies the performance obligations. 96 Table of Contents The Company applies the five-step model to contracts that are within the scope of ASC 606 only when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, for contracts within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to respective performance obligations when (or as) the respective performance obligations are satisfied. The Company evaluates its contracts with customers for the presence of significant financing components. If a significant financing component is identified in a contract and provides a financing benefit to the customer, the transaction price for the contract is adjusted to account for the financing portion of the arrangement, which is recognized as interest income over the financing term using the effective interest method. In determining the appropriate interest rates for significant financing components, the Company evaluates the credit profile of the customer and prevailing market interest rates and selects an interest rate in which it believes would be charged to the customer in a separate financing arrangement over a similar financing term. License and Royalty Revenue The Company licenses its NAV Technology Platform and other intellectual property rights to other biotechnology and pharmaceutical companies, including collaborators for the joint development and commercialization of its product candidates. The terms of the licenses vary, and licenses may be exclusive or non-exclusive and may be sublicensable by the licensee. Licenses may grant intellectual property rights for purposes of internal and preclinical research and development only, or may include the rights, or options to obtain future rights, to commercialize drug therapies for specific diseases using the Company’s NAV Technology Platform and other licensed rights. License agreements generally have a term at least equal to the life of the underlying patents, but are terminable at the option of the licensee. Consideration payable to the Company under its license agreements may include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products and (v) other consideration payable upon optional goods and services purchased by licensees. The Company’s license agreements are accounted for as contracts with customers within the scope of ASC 606, with the exception of transactions for which the counterparty is determined not to be a customer. At the inception of each license agreement, the Company determines the contract term for purposes of applying the requirements of ASC 606. Licenses are generally terminable at the option of the licensee with advance notice to the Company. For each license granted, including licenses granted upon the exercise of license options, the Company evaluates these termination rights to determine whether a substantive termination penalty would be incurred by the licensee upon termination. If the licensee incurs a substantive termination penalty upon termination, the contract term for revenue recognition purposes is generally equal to the stated term of the license, which is the life of the underlying licensed patents. Alternatively, if the licensee does not incur a substantive termination penalty upon termination, the contract term for revenue recognition purposes may be shorter than the stated term of the license, in which case the termination rights may be accounted for as contract renewal options. The determination of whether a substantive termination penalty is associated with the termination rights requires significant judgment. In making this determination, the Company considers, among other things, the nature of the intellectual property rights that would be returned to the Company upon termination, including the exclusivity of the licensed rights and the stage of development of the licensed products, the payment terms, including the amount and timing of non-refundable or guaranteed payments, and the business purpose of the termination rights granted to the licensee. Generally, the most significant judgment in determining whether a substantive termination penalty exists relates to the amount of any up-front or guaranteed non-refundable payments relative to the amount of annual payments that may be avoided by the licensee upon termination of the license. The Company considers all of the facts and circumstances relevant to each license when making this determination. Performance obligations under the Company’s license agreements may include (i) the delivery of intellectual property licenses, (ii) options granted to licensees to acquire additional licenses, to the extent the options represent material rights to the licensee, and (iii) research and development services to be performed by the Company related to licensed products. License agreements may provide licensees with contract renewal options or options to acquire additional licenses, goods or other services. Options are evaluated at the inception of the license agreement to determine whether they provide material rights to the licensee. In making this determination, the Company considers whether the options are priced at an incremental discount to the standalone selling price for the underlying licenses, goods or services, in which case the option is considered to be a material right to the licensee and is accounted for as a separate performance obligation under the current license agreement. At the inception of each license agreement which contains performance obligations for research and development services, the Company evaluates whether the license is distinct from the research and development services, which requires judgment. In making this determination, the Company considers, among other things, the stage of development of the licensed products and whether the research and development services will significantly impact further development of the licensed products. If it is determined that the license is not distinct from the research and development services, the license is combined with the research and development services into a single performance obligation. 97 Table of Contents The Company evaluates the transaction price of its license agreements at the inception of each agreement and at each reporting date. The transaction price includes the fixed consideration payable to the Company during the contract term, as well as any variable consideration to the extent that it is probable that a significant reversal of revenue will not occur in the future. Fixed consideration under the license agreements includes up-front and annual fees payable during the contract term. Variable consideration under the license agreements includes development and sales-based milestone payments, sublicense fees and royalties on sales of licensed products. Consideration contingent upon the exercise of options by a licensee is excluded from the transaction price and not accounted for as part of the license agreement until the option is exercised. The transaction price for each license agreement is allocated to the underlying performance obligations based on their relative standalone selling prices and recognized as revenue when (or as) the performance obligations are satisfied. Consideration allocated to performance obligations for the delivery of an intellectual property license is recognized as revenue in full upon the delivery of the license to the licensee. Consideration allocated to performance obligations for license options is recognized as revenue in full upon the earlier of the option exercise or expiration. The exercise of a license option by a licensee is accounted for as a new license for revenue recognition purposes. Consideration allocated to performance obligations for research and development services is recognized as revenue as the services are performed by the Company. Up-front and annual licenses fees payable to the Company over the contract term of each license are included in the transaction price, and the portion of this consideration allocated to the performance obligation for the delivery of the intellectual property license is recognized as revenue in full upon the delivery of the license to the licensee. If annual license fees are payable to the Company in periods beyond 12 months from the delivery of the license, a significant financing component is deemed to exist which provides a financing benefit to the licensee. If a significant financing component is identified, the Company adjusts the transaction price for the license to include only the present value of the annual license fees payable to the Company over the contract term. The discounted portion of the license fees is recognized as interest income from licensing over the financing period of the license. Development milestone payments are payable to the Company upon the achievement of specified development milestones. At the inception of each license agreement that contains development milestone payments, the Company evaluates whether the milestones are considered probable of achievement and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal will not occur in the future, milestone payments are included in the transaction price and recognized as revenue upon the delivery of the license. Milestone payments contingent on the achievement of development milestones that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved. At each reporting date, the Company re-evaluates the probability of achievement of each outstanding development milestone and, if necessary, adjusts the transaction price for any milestones for which the probability of achievement has changed due to current facts and circumstances. Any such adjustments are recorded on a cumulative catch-up basis and recognized as revenue in the period of the adjustment. Royalties on sales of licensed products, sales-based milestone payments, including milestones payable upon first commercial sales of licensed products, and sublicense fees based on the receipt of certain fees by licensees from any sublicensees are excluded from the transaction price of each license and recognized as revenue in the period that the related sales or sublicenses occur, provided that the associated license has been delivered to the licensee. Royalty revenue to date consists primarily of royalties on net sales of Zolgensma, which is a licensed product under the Company’s license agreement with Novartis Gene Therapies, a wholly owned subsidiary of Novartis AG (Novartis), for the development and commercialization of treatments for spinal muscular atrophy (SMA). The Company recognizes royalty revenue from net sales of Zolgensma in the period in which the underlying products are sold by Novartis Gene Therapies, which in certain cases may require the Company to estimate royalty revenue for periods of net sales which have not yet been reported to the Company. Estimated royalties are reconciled to actual amounts reported in subsequent periods, and any differences are recognized as an adjustment to royalty revenue in the period the royalties are reported. The Company receives payments from licensees based on the billing schedules established in each license agreement. Amounts recognized as revenue which have not yet been received from licensees, including unbilled royalties, are recorded as accounts receivable when the Company’s rights to the consideration are conditional solely upon the passage of time. Amounts recognized as revenue which have not yet been received from licensees are recorded as contract assets when the Company’s rights to the consideration are not unconditional. Contract assets are recorded as other current assets on the consolidated balance sheets if the consideration is expected to be realized within 12 months from the reporting date, or as other assets if the consideration is expected to be realized in periods beyond 12 months from the reporting date. If a licensee elects to terminate a license prior to the end of the license term, the licensed intellectual property is returned to the Company and any consideration recorded as accounts receivable or contract assets which is not contractually payable by the licensee is charged off as a reduction of license revenue in the period of the termination. Amounts received by the Company prior to the delivery of underlying performance obligations are deferred and 98 Table of Contents recognized as revenue upon the satisfaction of the performance obligations by the Company. Deferred revenue which is not expected to be recognized within 12 months from the reporting date is recorded as non-current on the consolidated balance sheets. Collaborative Arrangements The Company evaluates its agreements with collaboration partners to determine whether they are within the scope of ASC 808, Collaborative Arrangements (ASC 808). Such arrangements are within the scope of ASC 808 if they involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This evaluation is performed throughout the life of the arrangement based on any changes in the roles and responsibilities of the parties under the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company identifies the various transactions with the counterparty and determines if any unit of account is more reflective of a transaction with a customer and therefore should be accounted for within the scope of ASC 606. For transactions that are accounted for pursuant to ASC 808, an appropriate method of recognition and presentation is determined and consistently applied. For transactions that are accounted for pursuant to ASC 606, the Company applies the five-step model as described in its revenue recognition policies. For transactions accounted for as collaborative arrangements under ASC 808, payments to and from collaboration partners associated with multiple activities in a collaboration arrangement are classified based on the nature of each separate activity. Payments associated with development activities performed are recorded as research and development expense when owed to collaboration partners, or as a reduction of research and development expense when due from collaboration partners. Payments associated with commercialization activities performed are recorded as general and administrative expense when owed to collaboration partners, or as a reduction of general and administrative expense when due from collaboration partners. At the end of each reporting period, the Company records a net amount due to or from collaboration partners for activities performed by the parties under the collaboration. Cost of Revenues Cost of revenues consists primarily of sublicense fees and royalties on net sales of licensed products as specified in the Company’s agreements with its licensors. Sublicense fees are based on a percentage of license fees received by the Company from licensees and are recognized in the period that the underlying revenue is recognized. Royalties are based on a percentage of net sales of licensed products by licensees and are recognized in the period that the underlying sales occur. Amounts which are payable to licensors in periods beyond 12 months from the reporting date are recorded as non-current liabilities on the consolidated balance sheets. Research and Development Expenses Research and development costs are expensed as incurred in performing research and development activities. Advance payments for goods or services related to research and development activities are deferred and expensed as the goods are delivered or the services are performed. Research and development costs include salaries, wages, benefits and other personnel costs, laboratory and facilities costs, allocated overhead costs, license and milestone fees, and costs of goods and services associated with preclinical research and clinical trial activities, associated manufacturing-related activities, regulatory activities and other related services performed by third parties. At the end of each reporting period, the Company compares payments made to third-party service providers to the estimated expenses incurred based on the services provided and progress toward completion of the research or development objectives. Such estimates are subject to change as additional information becomes available. Depending on the timing of payments to the service providers and the estimated expenses incurred, the Company may record net prepaid or accrued research and development expenses relating to these costs. Up-front fees incurred in obtaining technology licenses, as well as milestone payments to licensors, are charged to research and development expense as incurred if the technology licensed has no alternative future use. Stock-based Compensation The Company accounts for its stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation (ASC 718). ASC 718 requires all stock-based awards to employees and nonemployees to be recognized as expense based on the grant date fair value of the awards. The Company’s stock-based awards include stock options and restricted stock units granted to employees and nonemployees and shares issued to employees under its employee stock purchase plan. The Company’s stock-based awards may be subject to either service or performance-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the estimated grant date fair value over the requisite service period of the award, which is generally the vesting term. Compensation expense related to awards 99 Table of Contents with performance-based vesting conditions is recognized based on the estimated grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable. The Company has elected to not estimate forfeitures of stock-based awards and accounts for forfeitures as they occur. The Company estimates the fair value of its stock option awards using the Black-Scholes option-pricing model, which requires the input of subjective assumptions, including (i) the fair value of the underlying common stock, (ii) the expected stock price volatility, (iii) the expected term of the award, (iv) the risk-free interest rate and (v) expected dividends. The Company estimates expected stock price volatility based on the historical volatility of its common stock over a period of time commensurate with the expected term of its stock option awards. Due to the lack of sufficient historical data, the Company estimates the expected term of its employee stock options using the “simplified” method, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. For stock options granted to nonemployees, the Company uses the contractual term of the award rather than expected term to estimate the fair value of the award. The Company estimates the risk-free interest rates for periods within the expected term of its options based on the rates of U.S. Treasury securities with maturity dates commensurate with the expected term of the associated awards. The Company assumes a dividend yield of zero for its common stock as it has never paid dividends and does not expect to pay dividends for the foreseeable future. The Company estimates the fair value of restricted stock units based on the fair value of the Company’s common stock on the date of the grant. Income Taxes Income taxes are accounted for in accordance with ASC 740, Income Taxes (ASC 740), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2023 and 2022 , the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company’s consolidated statements of operations and comprehensive income (loss). Restructuring Expenses The Company records costs and liabilities associated with exit and disposal activities in accordance with ASC 420, Exit or Disposal Cost Obligations (ASC 420) and ASC 712, Compensation - Nonretirement Postemployment Benefits (ASC 712 ) . Such costs are based on estimates of fair value in the period liabilities are incurred. The Company evaluates and adjusts these costs as appropriate for changes in circumstances as additional information becomes available. Please refer to Note 14 for further information regarding restructuring expenses. Net Income (Loss) Per Share Basic net income (loss) per share is calculated by dividing net income (loss) applicable to common stockholders by the weighted-average common shares outstanding during the period, without consideration for common stock equivalents. Diluted net income (loss) per share is calculated by adjusting the weighted-average common shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. Contingently convertible shares in which conversion is based on non-market-priced contingencies are excluded from the calculations of both basic and diluted net income (loss) per share until the contingency has been fully met. For purposes of the diluted net income (loss) per share calculation, common stock equivalents are excluded from the calculation of diluted net income (loss) per share if their effect would be anti-dilutive. 100 Table of Contents Comprehensive Income (Loss) Comprehensive income (loss) includes net income (loss) as well as unrealized gains and losses on available-for-sale debt securities, net of income tax effects and reclassification adjustments for realized gains and losses. Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements The Company did not adopt any new accounting standards during the year ended December 31, 2023 which had a material impact on the consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which enhances certain interim and annual disclosure requirements of reportable segment information, including information about significant segment expenses. Additionally, the standard requires entities with a single reportable segment to provide all disclosures required by ASC 280, Segment Reporting . The standard is effective for the Company for annual periods beginning January 1, 2024 and interim periods beginning January 1, 2025. Early adoption is permitted. The Company does not believe the application of this standard with have a material impact on its financial statement disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which enhances the disclosure of an entity's effective tax rate reconciliation and requires the disclosure of income taxes paid to be disaggregated by jurisdiction. The standard is effective for the Company beginning January 1, 2025, with early adoption permitted. The Company does not believe the application of this standard with have a material impact on its financial statement disclosures. 3. Marketable Securities The following tables present a summary of the Company’s marketable securities, which consist solely of available-for-sale debt securities (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value December 31, 2023 U.S. government and agency securities $ 71,811 $ 6 $ ( 1,248 ) $ 70,569 Certificates of deposit 6,572 — ( 106 ) 6,466 Corporate bonds 204,793 143 ( 2,364 ) 202,572 $ 283,176 $ 149 $ ( 3,718 ) $ 279,607 Amortized Cost Unrealized Gains Unrealized Losses Fair Value December 31, 2022 U.S. government and agency securities $ 134,485 $ — $ ( 3,492 ) $ 130,993 Certificates of deposit 7,555 1 ( 248 ) 7,308 Corporate bonds 340,752 — ( 10,803 ) 329,949 $ 482,792 $ 1 $ ( 14,543 ) $ 468,250 As of December 31, 2023 and 2022 , no available-for-sale debt securities had remaining maturities greater than three years. The amortized cost of marketable debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, or to the earliest call date for callable debt securities purchased at a premium. 101 Table of Contents As of December 31, 2023 and 2022 , the balance in accumulated other comprehensive loss consisted solely of unrealized gains and losses on available-for-sale debt securities, net of reclassification adjustments for realized gains and losses and income tax effects. Unrealized gain (loss) on available-for-sale securities, net, as presented in the consolidated statements of operations and comprehensive income (loss) consisted of the following (in thousands): Years Ended December 31, 2023 2022 2021 Unrealized gain (loss) before reclassifications $ 10,972 $ ( 12,904 ) $ ( 2,202 ) Realized losses (gains) reclassified to investment income — 72 ( 7 ) Unrealized gain (loss) on available-for-sale securities, net $ 10,972 $ ( 12,832 ) $ ( 2,209 ) The following tables present the fair values and unrealized losses of available-for-sale debt securities held by the Company in an unrealized loss position for less than 12 months and 12 months or greater (in thousands): Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses December 31, 2023 U.S. government and agency securities $ 12,877 $ ( 16 ) $ 52,686 $ ( 1,232 ) $ 65,563 $ ( 1,248 ) Certificates of deposit 965 ( 2 ) 5,257 ( 104 ) 6,222 ( 106 ) Corporate bonds 25,051 ( 48 ) 144,642 ( 2,316 ) 169,693 ( 2,364 ) $ 38,893 $ ( 66 ) $ 202,585 $ ( 3,652 ) $ 241,478 $ ( 3,718 ) Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses December 31, 2022 U.S. government and agency securities $ 91,498 $ ( 2,014 ) $ 38,495 $ ( 1,478 ) $ 129,993 $ ( 3,492 ) Certificates of deposit 4,484 ( 144 ) 2,087 ( 104 ) 6,571 ( 248 ) Corporate bonds 106,707 ( 3,866 ) 223,242 ( 6,937 ) 329,949 ( 10,803 ) $ 202,689 $ ( 6,024 ) $ 263,824 $ ( 8,519 ) $ 466,513 $ ( 14,543 ) As of December 31, 2023 , available-for-sale debt securities held by the Company which were in an unrealized loss position consisted of 86 investment grade security positions. The Company has the intent and ability to hold such securities until recovery, and based on the credit quality of the issuers and low severity of each unrealized loss position relative to its amortized cost basis, the Company did not identify any credit losses associated with its available-for-sale debt securities. The Company did not recognize any impairment or credit losses on available-for-sale debt securities during the years ended December 31, 2023, 2022 and 2021 . 102 Table of Contents 4. Fair Value of Financial Instruments Financial instruments reported at fair value on a recurring basis include cash equivalents and marketable securities. The following tables present the fair value of cash equivalents and marketable securities in accordance with the hierarchy discussed in Note 2 (in thousands): Quoted Significant prices other Significant in active observable unobservable markets inputs inputs (Level 1) (Level 2) (Level 3) Total December 31, 2023 Cash equivalents: Money market mutual funds $ — $ 13,024 $ — $ 13,024 Total cash equivalents — 13,024 — 13,024 Marketable securities: U.S. government and agency securities — 70,569 — 70,569 Certificates of deposit — 6,466 — 6,466 Corporate bonds — 202,572 — 202,572 Total marketable securities — 279,607 — 279,607 Total cash equivalents and marketable securities $ — $ 292,631 $ — $ 292,631 Quoted Significant prices other Significant in active observable unobservable markets inputs inputs (Level 1) (Level 2) (Level 3) Total December 31, 2022 Cash equivalents: Money market mutual funds $ — $ 58,611 $ — $ 58,611 Corporate bonds — 993 — 993 Total cash equivalents — 59,604 — 59,604 Marketable securities: U.S. government and agency securities — 130,993 — 130,993 Certificates of deposit — 7,308 — 7,308 Corporate bonds — 329,949 — 329,949 Total marketable securities — 468,250 — 468,250 Total cash equivalents and marketable securities $ — $ 527,854 $ — $ 527,854 Management estimates that the carrying values of its current accounts receivable, other current assets, accounts payable, accrued expenses and other current liabilities approximate fair value due to the short-term nature of those instruments. Accounts receivable which contain non-current portions and certain non-current payables reported as other liabilities are recorded at their present values using a discount rate that is based on prevailing market rates on the date the amounts were initially recorded. Management does not believe there have been any significant changes in market conditions or credit quality that would cause the discount rates initially used to be materially different from those that would be used as of December 31, 2023 to determine the present value of these instruments. Accordingly, management estimates that the carrying values of its non-current accounts receivable and other liabilities approximate the fair value of those instruments. Management estimates that the carrying value of the liability related to the sale of future royalties approximates fair value. As discussed in Note 7, the carrying value of the liability related to the sale of future royalties is based on the Company’s estimate of future royalties expected to be paid by the Company over the life of the arrangement, which are considered Level 3 inputs. Non-marketable Equity Securities Non-marketable equity securities are measured at cost less impairment, adjusted for observable price changes for identical or similar investments of the same issuer. The Company did not hold any non-marketable equity securities as of December 31, 2023 and 2022. No remeasurements or impairment losses were recorded on non-marketable equity securities during the years ended December 31, 2023, 2022 and 2021. 103 Table of Contents Prior to the acquisition of Corlieve Therapeutics SAS (Corlieve) by uniQure N.V. (uniQure) in July 2021, the Company held non-marketable equity securities of Corlieve, which were originally acquired by the Company in June 2 020 as consideration under a license and collaboration agreement with Corlieve. In connection with acquisition of Corlieve by uniQure in July 2021, the Company received proceeds of € 5.3 million ($ 6.1 million) from uniQure in exchange for its ownership interest in Corlieve, of which $ 5.6 million was received upon the closing of the acquisition and $ 0.5 million was received in August 2022 upon the expiration of a hold back period. The Company recorded a realized gain of $ 5.2 million during the year ended December 31, 2021 as a result of the acquisition of Corlieve by uniQure, which is included in investment income in the consolidated statements of operations and comprehensive income (loss). In addition to the upfront proceeds received in connection with uniQure's acquisition of Corlieve, the Company also became eligible to receive payments of up to € 37.1 million from uniQure contingent upon the achievement of various development and regulatory milestones. During the year ended December 31, 2023, the Company received € 1.9 million in milestone payments from uniQure and recognized investment income of $ 2.2 million related to the achievement of milestones during the period. As of December 31, 2023, there were € 35.3 million ($ 38.9 million as of December 31, 2023) in remaining milestones which have not been paid or achieved and have not been recognized in the consolidated financial statements. Proceeds contingent upon the achievement of the remaining milestones will be recognized as investment income in the period in which any uncertainty regarding realization is substantially resolved, which may not occur until the achievement of the underlying milestones. It is at least reasonably possible that some or all of the proceeds contingent upon these milestones will not be realized by the Company. 5. Property and Equipment, Net Property and equipment, net consists of the following (in thousands): As of December 31, 2023 2022 Laboratory and manufacturing equipment $ 75,632 $ 71,801 Computer equipment and software 4,700 4,910 Furniture and fixtures 7,052 6,965 Leasehold improvements 101,927 99,397 Total property and equipment 189,311 183,073 Accumulated depreciation and amortization ( 57,208 ) ( 41,388 ) Property and equipment, net $ 132,103 $ 141,685 During the years ended December 31, 2023, 2022 and 2021, the Company recorded depreciation and amortization expense of $ 17.3 million , $ 12.9 million and $ 9.6 million, respectively. 6. Leases 9804 Medical Center Drive In November 2018, the Company entered into an operating lease, which has been amended from time to time, for approximately 186,000 square feet of office, laboratory and manufacturing space at 9804 Medical Center Drive in Rockville, Maryland (the 9804 Medical Center Drive Lease), which now serves as the Company’s corporate, research and manufacturing headquarters. The initial construction of the building was performed by the landlord and the lease commenced in September 2020 upon delivery of the leased premises to the Company to make additional improvements to the building. Monthly payments under the lease began in September 2021 and escalate annually in accordance with the lease agreement. The lease expires in September 2036 , subject to extension and termination options held by the Company. The Company has an option to extend the term of the lease for up to 10 additional years and an option to terminate the lease, with payment of an early termination fee, after 12 years from the delivery of the leased premises to the Company. As of December 31, 2023, the Company’s extension and termination options under the 9804 Medical Center Drive Lease were excluded from the measurement of the right-of-use assets and lease liabilities as they were not reasonably certain of exercise. As required by the 9804 Medical Center Drive Lease, the Company has provided the landlord with an irrevocable letter of credit of $ 1.1 million which the landlord may draw upon in the event of any uncured default by the Company under the terms of the lease. Pursuant to the 9804 Medical Center Drive Lease, the Company received a $ 19.5 million tenant improvement allowance from the landlord to perform improvements to the leased premises. The tenant improvement allowance was recorded as a reduction of the right-of-use assets for the lease and is amortized on a straight-line basis as a reduction of lease expense over the term of the lease. The Company began occupation of a portion of the facility upon the completion of its construction in 2021. The remaining portion of the 104 Table of Contents building, primarily associated with the manufacturing facility, was activated upon the completion of its construction in 2022. As of December 31, 2023, the Company had recorded property and equipment at cost of $ 132.0 million related to the buildout at 9804 Medical Center Drive, of which $ 41.2 million was placed in service upon the initial occupation of the building in 2021, $ 77.6 million was placed in service upon the activation of the manufacturing facility in 2022, $ 2.6 million was placed in service in 2023 and the remaining $ 10.6 million has not yet been placed in service. As of December 31, 2023, the Company had recorded right-of-use assets of $ 44.8 million and lease liabilities of $ 71.9 million related to the 9804 Medical Center Drive Lease. 9712 Medical Center Drive In March 2015, the Company entered into an operating lease for office space at 9712 Medical Center Drive in Rockville, Maryland (the 9712 Medical Center Drive Lease). The lease term commenced in April 2015 , and monthly payments under the lease began in October 2015 and escalate annually in accordance with the lease agreement. The 9712 Medical Center Drive Lease has been amended from time to time to include additional office and laboratory space at an adjacent building located at 9714 Medical Center Drive and extend the term of the lease, which expires in February 2027, subject to extension options held by the Company. The Company has an option to extend the term of the lease for three additional years, as well as an option to extend the lease term to be coterminous with the 9804 Medical Center Drive Lease, which expires in September 2036 . As of December 31, 2023, the Company’s extension options under the 9712 Medical Center Drive Lease were excluded from the measurement of the right-of-use assets and lease liabilities as they were not reasonably certain of exercise. The Company received a $ 0.4 million tenant improvement allowance from the landlord which was recorded as a reduction of the right-of-use assets for the lease and is amortized on a straight-line basis as a reduction of lease expense over the term of the lease. As of December 31, 2023, the Company had recorded right-of-use assets of $ 4.6 million and lease liabilities of $ 5.1 million related to the 9712 Medical Center Drive Lease. Other Leases In May 2016, the Company entered into an operating lease for office space in New York, New York (the New York Lease), which has since been amended to include additional office space and extend the term of the lease. The lease term commenced in July 2016 and expires in April 2027 . The Company received a $ 0.7 million tenant improvement allowance from the landlord which was recorded as a reduction of the right-of-use assets for the lease and is amortized on a straight-line basis as a reduction of lease expense over the term of the lease. As required by the New York Lease, the Company has provided the landlord with an irrevocable letter of credit of $ 0.2 million which the landlord may draw upon in the event of any uncured default by the Company under the terms of the lease. As of December 31, 2023, the Company had recorded right-of-use assets of $ 2.4 million and lease liabilities of $ 3.1 million related to the New York Lease. In October 2022, the Company entered into an operating lease for office space in Washington, D.C. (the DC Lease). The lease term commenced in October 2022 and expires in October 2027 . The Company has an option to extend the term of the lease for five additional years. As of December 31, 2023, the Company’s extension option under the DC Lease was excluded from the measurement of the right-of-use assets and lease liabilities as it was not reasonably certain of exercise. The Company recorded the right-of-use assets and lease liabilities related to the DC Lease upon its commencement in October 2022. As of December 31, 2023 the Company had recorded right-of-use assets of $ 5.3 million and lease liabilities of $ 5.3 million related to the DC Lease. The Company leases additional office, laboratory and warehousing space, as well as laboratory and other equipment, under operating leases with various expiration dates through 2029 , including leases which have been executed but have not yet commenced. 105 Table of Contents Operating Lease Information All of the Company’s leases are classified as operating leases. The following table summarizes the Company’s lease costs and supplemental cash flow information related to its operating leases (in thousands): Years Ended December 31, 2023 2022 2021 Operating lease cost $ 11,107 $ 9,570 $ 9,729 Variable lease cost 2,263 1,727 2,348 Total lease cost $ 13,370 $ 11,297 $ 12,077 Cash paid (received) for amounts included in operating lease liabilities $ 11,861 $ 5,697 $ ( 6,765 ) Right-of-use assets acquired through operating lease liabilities $ 1,132 $ 8,662 $ 1,955 Cash paid (received) for amounts included in operating lease liabilities for the years ended December 31, 2023, 2022 and 2021 includes $ 0.1 million, $ 1.3 million and $ 11.4 million, respectively, received by the Company during the period under its tenant improvement allowances, which were deemed in-substance lease payments and included in the calculation of the lease liability. Short-term lease expense for the years ended December 31, 2023, 2022 and 2021 was not material and is included in operating lease cost in the table above. Variable lease cost under the Company’s operating leases includes items such as common area maintenance, utilities, taxes and other charges. The following table presents the weighted-average remaining lease term and weighted-average discount rate of the Company’s operating leases: As of December 31, 2023 2022 Weighted-average remaining lease term (years) 11.0 11.7 Weighted-average discount rate 5.7 % 5.7 % The following table presents a reconciliation of the undiscounted future minimum lease payments remaining under the Company’s operating leases to the amounts reported as operating lease liabilities on the consolidated balance sheet as of December 31, 2023 (in thousands): As of December 31, 2023 Undiscounted future minimum lease payments: 2024 $ 11,936 2025 12,750 2026 12,643 2027 10,003 2028 7,940 Thereafter 67,039 Total undiscounted future minimum lease payments 122,311 Amount representing imputed interest ( 33,021 ) Total operating lease liabilities 89,290 Current portion of operating lease liabilities ( 7,068 ) Operating lease liabilities, non-current $ 82,222 The table above excludes future minimum lease payments for leases which were executed but had not yet commenced as of December 31, 2023, the total of which were not material. 106 Table of Contents 7. Liability Related to Sale of Future Royalties In December 2020, the Company entered into a royalty purchase agreement (the Royalty Purchase Agreement) with HCR. Under the Royalty Purchase Agreement, HCR purchased the Company’s rights to a capped amount of Zolgensma royalty payments under the Company’s license agreement (the Novartis License) with Novartis Gene Therapies, including $ 4.0 million of royalty payments received by the Company in the fourth quarter of 2020 (the Pledged Royalties). In consideration for these rights, HCR paid the Company $ 200.0 million (the Purchase Price), less $4.0 million representing the payment of the Pledged Royalties to HCR. Beginning upon the effective date of the Royalty Purchase Agreement, Zolgensma royalty payments, up to a specified threshold, shall be paid to HCR, net of upstream royalties payable by the Company to certain licensors in accordance with existing license agreements. Pursuant to the Royalty Purchase Agreement, the total amount of royalty payments to be received by HCR is subject to an increasing cap (the Cap Amount) equal to (i) $ 260.0 million applicable for the period from the effective date of the Royalty Purchase Agreement through November 7, 2024, and (ii) $ 300.0 million applicable for the period from November 8, 2024 through the effective date of termination of the Novartis License. If, on or prior to the defined dates for each Cap Amount, the total amount of royalty payments received by HCR equals or exceeds the Cap Amount applicable to such date, the Royalty Purchase Agreement will automatically terminate and all rights to the Zolgensma royalty payments will revert back to the Company. The Company has no obligation to repay any amounts to HCR if total future Zolgensma royalty payments are not sufficient to achieve the applicable Cap Amount prior to the termination of the Novartis License. The Company has a call option to repurchase its rights to the purchased royalties from HCR for a repurchase price equal to, as of the option exercise date, $ 300.0 million minus the total amount of royalty payments received by HCR; provided, however, that with respect to a call option exercised on or before November 7, 2024, in the event that the then applicable Cap Amount minus the total amount of royalty payments received by HCR is less than $ 1.0 million, the repurchase price shall equal such difference. The proceeds received from HCR of $ 196.0 million were recorded as a liability, net of transaction costs of $ 3.5 million, which is amortized over the estimated life of the arrangement using the effective interest method. In order to determine the amortization of the liability, the Company is required to estimate the total amount of future royalty payments to be received by HCR, subject to the Cap Amount, over the life of the arrangement. The total amount of royalty payments received by HCR under the Royalty Purchase Agreement, less the net proceeds received by the Company of $ 192.5 million, is recorded as interest expense over the life of the arrangement using the effective interest method. Due to its continuing involvement in the Novartis License, the Company continues to recognize royalty revenue on net sales of Zolgensma and records the royalty payments to HCR as a reduction of the liability when paid. As such payments are made to HCR, the balance of the liability will be effectively repaid over the life of the Royalty Purchase Agreement. The Company estimates the effective interest rate used to record interest expense under the Royalty Purchase Agreement based on its estimate of future royalty payments to be received by HCR. As of December 31, 2023, the estimated effective interest rate under the Royalty Purchase Agreement was 4.8 % . Over the life of the arrangement, the actual effective interest rate will be affected by the amount and timing of the royalty payments received by HCR and changes in the Company’s forecasted royalties. At each reporting date, the Company reassesses its estimate of total future royalty payments to be received by HCR at the applicable Cap Amount, and prospectively adjusts the effective interest rate and amortization of the liability as necessary. The following table presents the changes in the liability related to the sale of future royalties under the Royalty Purchase Agreement with HCR (in thousands): Liability Related to Sale of Future Royalties Balance at December 31, 2021 $ 171,349 Zolgensma royalties paid to HCR ( 56,219 ) Interest expense recognized 22,476 Balance at December 31, 2022 137,606 Zolgensma royalties paid to HCR ( 49,574 ) Interest expense recognized 6,020 Balance at December 31, 2023 94,052 Current portion of liability related to sale of future royalties ( 50,567 ) Liability related to sale of future royalties, non-current $ 43,485 107 Table of Contents 8. Commitments and Contingencies In-licensed Technology The Company in-licenses intellectual property from third parties for technology and know-how used in its product candidates and development programs, some of which is further sublicensed to NAV Technology Licensees and collaboration partners. In-licenses may require the Company to make future payments relating to sublicense fees, milestone fees and royalties on future sales of licensed products. Additionally, the Company may be responsible for the cost of the maintenance of the intellectual property as incurred by its licensors. Up-front fees to obtain licensed technology, as well as associated milestone fees, are recorded as research and development expenses if the technology has no alternative future use. Sublicense fees are based on a specified percentage of license fees earned by the Company as a result of sublicensing the technology to third parties and are recorded as cost of revenues. Royalties due to licensors on sales of licensed products, including sales by NAV Technology Licensees, are recorded as cost of revenues. Patent maintenance costs are recorded as general and administrative expenses. Please refer to Note 10 for information on licenses granted by the Company and collaboration agreements with third parties. The Trustees of the University of Pennsylvania In February 2009, the Company entered into a license agreement, which has been amended from time to time (as amended, the Penn License), with The Trustees of the University of Pennsylvania (together with the University of Pennsylvania, Penn) for exclusive, worldwide rights to certain patents owned by Penn underlying the Company’s NAV Technology Platform, as well as exclusive rights to certain data, results and other information. Pursuant to the originally agreed upon Penn License, the Company was obligated to pay Penn royalties on net sales of licensed products and sublicense fees. Additionally, the Company was obligated to reimburse Penn for certain costs incurred related to the maintenance of the licensed patents. In April 2019, the Penn License was amended to include exclusive license rights to certain patent rights and know-how, including research data and other information, relating to the treatment of late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease. In consideration for the additional licensed rights, and in addition to any consideration owed under the license prior to the amendment, the Company paid Penn an up-front fee and is obligated to pay milestone fees of up to $ 20.5 million upon the achievement of various development and sales-based milestones and additional royalties on net sales of licensed products for the treatment of CLN2 disease. From the inception of the agreement through December 31, 2023, the Company had incurred $ 0.5 million for development milestones achieved, or deemed probable of achievement, under the Penn License. In March 2022, the Company and Penn entered into a letter agreement (the Penn Letter Agreement) pursuant to which the Company will pay to Penn a total of $ 20.0 million, consisting of (i) $ 8.0 million paid in April 2022 to satisfy payment of any sublicense fees due or owed in the future under the Penn License as a result of the Company’s collaboration and license agreement with AbbVie Global Enterprises Ltd., and (ii) $ 12.0 million to satisfy any other past or future obligations of the Company to pay sublicense fees under the Penn License, which is payable in four equal annual installments of $ 3.0 million beginning in March 2023. The Penn Letter Agreement amended the Penn License to remove the Company’s obligations to pay sublicense fees under the license agreement. The Company remains obligated to pay Penn royalties on net sales of licensed products, milestone fees and reimbursement of certain patent maintenance costs in accordance with the Penn License. The Company recognized a charge of $ 9.2 million as cost of revenues upon the execution of Penn Letter Agreement in March 2022, which consisted of $ 17.3 million representing the present value of the $ 20.0 million payable under the Penn Letter Agreement, less $ 8.1 million in sublicense fees previously recognized as expense by the Company in prior periods and accrued as liabilities prior to the effectiveness of the Penn Letter Agreement. The present value discount is accreted as interest expense over the contractual payment period using the effective interest method. Expenses incurred by the Company related to the Penn License were recorded as follows (in thousands): Years Ended December 31, 2023 2022 2021 Cost of revenues $ — $ 9,242 $ 8,046 Research and development 500 — — General and administrative 935 715 706 Interest expense 842 778 — $ 2,277 $ 10,735 $ 8,752 108 Table of Contents As of December 31, 2023, the Company had recorded $ 8.2 million payable under the Penn License, net of present value discount, of which $ 2.6 million was included in accrued expenses and other current liabilities, and $ 5.6 million was included in other liabilities on the consolidated balance sheet. As of December 31, 2022, the Company had recorded $ 10.3 million payable under the Penn License, net of present value discount, of which $ 2.3 million was included in accounts payable and accrued expenses and other current liabilities, and $ 8.0 million was included in other liabilities on the consolidated balance sheet. GlaxoSmithKline In March 2009, the Company entered into a license agreement, which was amended in April 2009 (as amended, the GSK License), with GlaxoSmithKline LLC (GSK) for exclusive, worldwide rights to certain patents underlying the Company’s NAV Technology Platform which are owned by Penn and exclusively licensed to GSK. Pursuant to the GSK License, the Company is obligated to pay GSK royalties on net sales of licensed products and sublicense fees. Additionally, the Company is obligated to reimburse GSK for certain costs incurred related to the maintenance of the licensed patents. The Company was also obligated to pay $ 1.5 million to GSK upon the achievement of various milestones, all of which have been achieved and paid as of December 31, 2023. In connection with the execution of the Penn Letter Agreement in March 2022, the Company’s royalty obligations under the GSK License were assigned by GSK to Penn. Beginning upon the effective date of the Penn Letter Agreement in March 2022, any royalties payable by the Company under the GSK License shall be paid to Penn rather than GSK. The Company remains obligated to pay GSK sublicense fees and reimbursement of certain patent maintenance costs in accordance with the GSK License. Expenses incurred by the Company related to the GSK License were recorded as follows (in thousands): Years Ended December 31, 2023 2022 2021 Cost of revenues: Royalties on net sales of Zolgensma $ 37,043 $ 44,691 $ 43,161 Other cost of revenues 170 612 626 Total cost of revenues 37,213 45,303 43,787 General and administrative 476 964 889 $ 37,689 $ 46,267 $ 44,676 As of December 31, 2023, the Company had recorded $ 12.3 million payable under the GSK License, of which $ 12.2 million was included in accrued expenses and other current liabilities, and $ 0.1 million was included in other liabilities on the consolidated balance sheet. As of December 31, 2022, the Company had recorded $ 14.1 million payable under the GSK License, of which $ 13.8 million was included in accounts payable and accrued expenses and other current liabilities, and $ 0.2 million was included in other liabilities on the consolidated balance sheet. Clearside Biomedical In August 2019, the Company entered into an option and license agreement with Clearside Biomedical, Inc. (Clearside) pursuant to which the Company was granted an option to exclusively license the worldwide rights to certain patents related to Clearside’s proprietary, in-office SCS Microinjector™ for the delivery of ABBV-RGX-314 to the suprachoroidal space to treat wet age-related macular degeneration (wet AMD), diabetic retinopathy (DR) and other diseases. The Company exercised its license option in October 2019, resulting in a payment of $ 1.6 million to Clearside which was recognized as research and development expense upon exercise. Additionally, the Company is obligated to pay milestone fees of up to $ 136.0 million upon the achievement of various development and sales-based milestones, as well as royalties on net sales of licensed products using the SCS Microinjector. Clearside is responsible for supplying the SCS Microinjector to the Company to support all preclinical, clinical and commercial needs. From the inception of the agreement through December 31, 2023, the Company had incurred $ 3.0 million for development milestones achieved, or deemed probable of achievement, under the agreement. Other Licenses In November 2014, the Company entered into a license agreement, which has been amended from time to time, with Regents of the University of Minnesota (Minnesota), for an exclusive license to Minnesota’s interest in certain patent rights which are co-owned by Minnesota and the Company to commercialize products covered by the licensed patent rights in any country or territory in which a licensed patent has been issued and is unexpired, or a licensed patent application is pending. Pursuant to the license agreement, the 109 Table of Contents Company is obligated to pay Minnesota annual maintenance fees, royalties on net sales, sublicense fees and fees upon the achievement of various milestones. Additionally, the Company is obligated to pay for certain costs incurred related to the maintenance of the licensed patents. In August 2018, the Company entered into a license agreement with Emory University (Emory) for an exclusive license to Emory’s interest in certain patent rights which are co-owned by Emory and the Company to commercialize products covered by the licensed patent rights in any country or territory. Pursuant to the license agreement, the Company is obligated to reimburse Emory for patent prosecution and maintenance expenses and pay Emory annual maintenance fees under certain circumstances, royalties on net sales, sublicense fees and fees upon the achievement of various milestones for the first licensed product. In June 2022, the Company entered into a license agreement with Johns Hopkins University (JHU) for an exclusive license to JHU's interest in certain patent rights which are co-owned by JHU and the Company to commercialize products covered by the licensed patent rights in any country or territory. Pursuant to the license agreement, the Company paid JHU an upfront fee and is obligated to pay JHU royalties on net sales, minimum annual royalties, sublicense fees and fees upon the achievement of various milestones for the first two licensed products. Additionally, the Company is obligated to pay for certain costs incurred related to the maintenance of the licensed patents. Other Funding Commitments In the normal course of business, the Company enters into agreements with contract research organizations, contract manufacturing organizations and other third parties for services to be provided to the Company. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The actual amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of services to be provided to the Company. Guarantees and Indemnifications In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. The Company’s potential exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. To date, the Company has no t paid any claims or been required to defend any action related to its indemnification obligations. As of December 31, 2023 and 2022 , the Company did no t have any material indemnification claims that were probable or reasonably possible and consequently had not recorded any related liabilities. Settlement Agreement In the fourth quarter of 2022, the Company entered into a settlement agreement with a third party pursuant to which the Company released certain claims regarding infringement of the Company's intellectual property. In consideration for the release of claims made by the Company, the Company was paid $ 7.5 million, which was recorded as other operating income in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2022. 9. Capitalization As of December 31, 2023 and 2022 , the authorized capital stock of the Company included 100,000,000 shares of common stock, par value $ 0.0001 per share, and 10,000,000 shares of preferred stock, par value $ 0.0001 per share. The Company’s restated certificate of incorporation and bylaws contain the rights, preferences and privileges of the Company’s stockholders and their respective shares. Shares of common stock reserved for future issuance were as follows (in thousands): As of December 31, 2023 2022 Reserved for issuance under equity incentive plans 12,422 11,077 Reserved for issuance under employee stock purchase plan 1,018 1,122 13,440 12,199 110 Table of Contents Public Offerings In January 2021, the Company completed a public offering of 4,899,000 shares of its common stock (inclusive of 639,000 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares) at a price of $ 47.00 per share. The aggregate net proceeds received by the Company from the offering, inclusive of the underwriters’ option exercise, were $ 216.1 million, net of underwriting discounts and commissions and offering expenses payable by the Company. Private Placement On July 7, 2023, the Company sold an aggregate of 257,466 shares of its common stock to Redmile Biopharma Investments III, L.P. (Redmile) at a purchase price of $ 19.42 per share, which was the closing price of the common stock on July 6, 2023 (the Private Placement). The Company received aggregate net proceeds from the Private Placement of $ 4.9 million, net of offering expenses. The Private Placement was conducted in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act. At-the-Market Offering Program On September 1, 2023, the Company entered into an ATM Equity Offering SM Sales Agreement with BofA Securities, Inc. (BofA) pursuant to which the Company may offer and sell shares of its common stock having an aggregate offering price of up to $ 150.0 million from time to time through BofA, acting as the Company's sales agent (the ATM Program). As of December 31, 2023, no shares of common stock had been sold under the ATM Program. 10. License and Collaboration Agreements Please refer to Note 8 for information on license agreements for technology in-licensed by the Company from third parties. License and Royalty Revenue As of December 31, 2023 , the Company’s NAV Technology Platform was being applied by NAV Technology Licensees in one commercial product, Zolgensma, and in the development of a number of other licensed products. Additionally, the Company has licensed intellectual property rights to collaborators for the joint development of certain product candidates. Consideration to the Company under its license agreements may include: (i) up-front and annual fees, (ii) milestone payments based on the achievement of certain development and sales-based milestones, (iii) sublicense fees, (iv) royalties on sales of licensed products and (v) other consideration payable upon optional goods and services purchased by licensees. Sublicense fees vary by license and range from a mid-single digit percentage to a low-double digit percentage of license fees received by licensees as a result of sublicenses. Royalties on net sales of commercialized products vary by license and range from a mid-single digit percentage to a low double-digit percentage of net sales by licensees. License and royalty revenue consisted of the following (in thousands): Years Ended December 31, 2023 2022 2021 Zolgensma royalties $ 85,319 $ 101,919 $ 94,978 AbbVie collaboration and license agreement — — 370,000 Other license and royalty revenue 4,923 10,805 5,369 Total license and royalty revenue $ 90,242 $ 112,724 $ 470,347 Outstanding development milestone payments are evaluated each reporting period and are only included in the transaction price of each license and recognized as license revenue to the extent the milestones are considered probable of achievement. Sales-based milestones are excluded from the transaction price of each license agreement and recognized as royalty revenue in the period of achievement. As of December 31, 2023, the Company’s license agreements, excluding additional licenses that could be granted upon the exercise of options by licensees, contained unachieved milestones which could result in aggregate milestone payments to the Company of up to $ 1.55 billion, including (i) $ 531.8 million upon the commencement of various stages of clinical trials, (ii) $ 140.0 million upon the submission of regulatory approval filings or upon regulatory approval of licensed products, and (iii) $ 875.0 million upon the achievement of specified sales targets for licensed products, including milestones payable upon the first commercial sale of licensed products. To the extent the milestone payments are realized by the Company, the Company will be obligated to pay sublicense fees to licensors based on a specified percentage of the fees earned by the Company. The achievement of these milestones is highly dependent on the successful development and commercialization of licensed products and it is at least reasonably possible that some or all of the milestone fees will not be realized by the Company. 111 Table of Contents Changes in Accounts Receivable, Contract Assets and Deferred Revenue The following table presents the balances of the Company’s net accounts receivable, contract assets and deferred revenue, as well as other information regarding revenue recognized, during the periods presented (in thousands): Years Ended December 31, 2023 2022 2021 Accounts receivable, net, current and non-current: Beginning of period $ 29,586 $ 34,701 $ 46,266 End of period $ 25,491 $ 29,586 $ 34,701 Contract assets: Beginning of period $ — $ 1,074 $ 350 End of period $ — $ — $ 1,074 Deferred revenue: Beginning of period $ 1,829 $ 3,333 $ 4,232 End of period $ 148 $ 1,829 $ 3,333 Revenue recognized during the period from: Amounts included in deferred revenue at beginning of period $ 1,708 $ 3,333 $ 390 Performance obligations satisfied in previous periods $ 87,152 $ 101,921 $ 98,575 As of December 31, 2023 , the Company had recorded deferred revenue of $ 0.1 million which represents consideration received or unconditionally due from licensees for performance obligations that have not yet been satisfied by the Company. Unsatisfied performance obligations as of December 31, 2023 consisted of research and development services to be performed by the Company related to licensed products, which will be satisfied as the research and development services are performed. As of December 31, 2023, the aggregate transaction price of the Company's license agreements allocated to performance obligations not yet satisfied, or partially satisfied, was $ 1.2 million, which is expected to be satisfied over a period of two to three years . Revenue recognized from performance obligations satisfied in previous periods, as presented in the table above, was primarily attributable to Zolgensma royalties, sublicense fees earned from licensees and changes in the transaction prices of the Company’s license agreements. Changes in transaction prices were primarily attributable to development milestones achieved or deemed probable of achievement during the periods which were previously not considered probable of achievement, resulting in a cumulative catch-up adjustment to revenue. Revenue recognized during the years ended December 31, 2023, 2022 and 2021 resulting from performance obligations satisfied in previous periods includ ed $ 2.0 million, zero and $ 0.5 million, respectively, in cumulative catch-up adjustments for changes in the probability of achievement of development milestones. Accounts Receivable, Contract Assets and the Allowance for Credit Losses Accounts receivable, net consisted of the following (in thousands): As of December 31, 2023 2022 Current accounts receivable: Billed to customers $ 265 $ 280 Unbilled Zolgensma royalties 24,128 27,027 Due from Abeona, net of present value discount 4,587 — Other unbilled 397 775 Allowance for credit losses ( 4,587 ) — Current accounts receivable, net 24,790 28,082 Non-current accounts receivable: Due from Abeona, net of present value discount — 4,152 Other unbilled 701 1,504 Allowance for credit losses — ( 4,152 ) Non-current accounts receivable, net 701 1,504 Total accounts receivable, net $ 25,491 $ 29,586 112 Table of Contents The following table presents the changes in the allowance for credit losses related to accounts receivable and contract assets for the years ended December 31, 2023 and 2022 (in thousands): Allowance for Credit Losses Accounts Receivable Contract Assets Balance at December 31, 2021 $ 3,758 $ — Changes in present value discount of receivables 394 — Balance at December 31, 2022 4,152 — Changes in present value discount of receivables 435 — Balance at December 31, 2023 $ 4,587 $ — The Company’s allowance for credit losses as of December 31, 2023 and 2022 was related solely to accounts receivable from Abeona. Please refer to the section below, "Settlement Agreement with Abeona Therapeutics", for further information regarding amounts due from Abeona and the associated allowance for credit losses. The Company did no t record a provision for credit losses for the years ended December 31, 2023 and 2022. The Company recorded credit recoveries of $ 2.6 million during the year ended December 31, 2021. Zolgensma License with Novartis Gene Therapies In March 2014, the Company entered into an exclusive license agreement (as amended, the Novartis License) with Novartis Gene Therapies. Under the Novartis License, the Company granted Novartis Gene Therapies an exclusive, worldwide commercial license, with rights to sublicense, to the NAV Technology Platform, as well as other certain rights, for the treatment of SMA in humans by in vivo gene therapy. In consideration for the rights granted under the license, Novartis Gene Therapies paid the Company (i) an up-front fee of $ 2.0 million upon the execution of the agreement in 2014, (ii) license fees totaling $ 180.0 million upon the amendment of the agreement in January 2018 and the subsequent acquisition of AveXis, Inc. (now Novartis Gene Therapies) by Novartis in May 2018, (iii) total cumulative payments of $ 12.3 million upon the achievement of various development milestones, and (iv) a sales-based milestone payment of $ 80.0 million upon the achievement of $ 1.0 billion in cumulative net sales of Zolgensma in the third quarter of 2020. In addition to the consideration above, Novartis Gene Therapies is obligated to pay to the Company fixed annual fees, royalties on net sales of licensed products and a percentage of any sublicense fees received by Novartis Gene Therapies from sublicensees for the licensed intellectual property rights. Royalties are payable by Novartis Gene Therapies at a mid-single to low double-digit percentage of net sales of licensed products using the NAV AAV9 vector, and a low double-digit percentage of net sales of licensed products using a licensed vector other than NAV AAV9, and are subject to reduction in specified circumstances. In 2019, Novartis Gene Therapies launched commercial sales of Zolgensma, a licensed product under the Novartis License. In accordance with the Novartis License, the Company receives royalties on net sales of Zolgensma. All development and sales-based milestones under the Novartis License have been achieved and there are no further milestone payments payable to the Company under the license agreement. The Company recognized the following amounts under the Novartis License (in thousands): Years Ended December 31, 2023 2022 2021 Zolgensma royalties $ 85,319 $ 101,919 $ 94,978 Other license revenue — 31 — Total license and royalty revenue $ 85,319 $ 101,950 $ 94,978 Interest income from licensing $ 29 $ 92 $ 22 As of December 31, 2023 and 2022 , the Company had recorded total accounts receivable of $ 24.3 million and $ 27.3 million, respectively, from Novartis Gene Therapies under the Novartis License, which consisted primarily of Zolgensma royalties receivable. The Zolgensma royalties receivable recorded as of December 31, 2023 included $ 12.5 million expected to be paid to HCR in accordance with the Royalty Purchase Agreement discussed in Note 7. 113 Table of Contents Settlement Agreement with Abeona Therapeutics In November 2021, the Company entered into a settlement agreement and mutual release with Abeona (the Settlement Agreement) related to claims associated with a license agreement between the parties which was terminated in May 2020. The Settlement Agreement resolved all arbitration and legal proceedings and mutually released each party from any and all claims under the terminated license agreement. Pursuant to the Settlement Agreement, Abeona will pay the Company a total of $ 30.0 million as follows: (i) $ 20.0 million which was paid in November 2021, (ii) $ 5.0 million which was paid in November 2022, and (iii) $ 5.0 million payable on the earlier of the third anniversary of the Settlement Agreement in November 2024 or the closing of a specified type of transaction by Abeona. As of December 31, 2023 and 2022, the Company had recorded accounts receivable of $ 4.6 million and $ 4.2 million, respectively, associated with the remaining amounts due from Abeona under the Settlement Agreement. The receivable of $ 4.6 million as of December 31, 2023 consisted of the $ 5.0 million payment due by November 2024, net of discount to present value. While the Company anticipates taking appropriate measures to enforce the full collection of all amounts due from Abeona under the Settlement Agreement, the Company assessed the collectability of the accounts receivable from Abeona as it relates to credit risk. In performing this assessment, the Company evaluated Abeona’s credit profile and financial condition, as well its expectations regarding Abeona’s future cash flows and ability to satisfy the contractual obligations of the Settlement Agreement. As a result of its analysis, the Company recorded an allowance for credit losses of $ 4.6 million and $ 4.2 million as of December 31, 2023 and 2022, respectively, related to the accounts receivable due from Abeona. The Company recorded credit recoveries of $ 2.6 million during the year ended December 31, 2021 as a result of changes in estimates regarding amounts collectable from Abeona under the terminated license agreement and subsequent Settlement Agreement. No credit losses or recoveries were recorded on the Abeona receivable during the years ended December 31, 2023 and 2022. The present value discount of the receivable is accreted as interest income from licensing through the contractual due date using the effective interest method. The Company has elected to record increases in the allowance for credit losses associated with the accretion of the present value discount as a reduction of the associated interest income, resulting in no interest income recognized during the periods related to the accretion of the present value discount on the Abeona receivable. Collaboration Agreements AbbVie Collaboration and License Agreement Effective in November 2021, the Company entered into a collaboration and license agreement with AbbVie Global Enterprises Ltd. (AbbVie), a subsidiary of AbbVie Inc., to jointly develop and commercialize ABBV-RGX-314, the Company’s product candidate for the treatment of wet AMD, DR and other chronic retinal diseases (the AbbVie Collaboration Agreement). Pursuant to the AbbVie Collaboration Agreement, the Company granted AbbVie a co-exclusive license to develop and commercialize ABBV-RGX-314 in the United States and an exclusive license to develop and commercialize ABBV-RGX-314 outside the United States. The Company and AbbVie will collaborate to develop ABBV-RGX-314 in the United States, and AbbVie will be responsible for the development of ABBV-RGX-314 in specified markets outside the United States. Through December 31, 2022, the Company was responsible for the development expenses related to certain ongoing clinical trials of ABBV-RGX-314 and the parties shared the additional development expenses related to ABBV-RGX-314. Beginning on January 1, 2023, AbbVie became responsible for the majority of all ABBV-RGX-314 development expenses. The Company will lead the manufacturing of ABBV-RGX-314 for clinical development and U.S. commercial supply, and AbbVie will lead the manufacturing of ABBV-RGX-314 for commercial supply outside the United States. Manufacturing expenses will be allocated between the parties in accordance with the terms of the AbbVie Collaboration Agreement and supply agreements determined in accordance with the agreement. If requested by AbbVie, the Company will manufacture up to a specified portion of ABBV-RGX-314 for commercial supply outside the United States at a price specified in the agreement. AbbVie will lead the commercialization of ABBV-RGX-314 globally, and the Company will participate in U.S. commercialization efforts as provided under a commercialization plan determined in accordance with the agreement. The Company and AbbVie will share equally in the net profits and net losses associated with the commercialization of ABBV-RGX-314 in the United States. Outside the United States, AbbVie will be responsible, at its sole cost, for the commercialization of ABBV-RGX-314. In consideration for the rights granted under the AbbVie Collaboration Agreement, AbbVie paid the Company an up-front fee of $ 370.0 million upon the effective date of the agreement in November 2021 and is required to pay to the Company up to $ 1.38 billion upon the achievement of specified development and sales-based milestones, of which $ 562.5 million are based on development milestones and $ 820.0 million are sales-based milestones. AbbVie is also required to pay to the Company tiered royalties on net sales of ABBV-RGX-314 outside the United States at percentages in the mid-teens to low twenties, subject to specified offsets and reductions. 114 Table of Contents The AbbVie Collaboration Agreement contains provisions for termination, including termination for convenience by AbbVie. Contemporaneously with entering into the AbbVie Collaboration Agreement, the Company entered into a sublicense agreement with AbbVie (the AbbVie Sublicense Agreement) pursuant to which the Company granted AbbVie an exclusive sublicense to exploit licensed products in connection with the AbbVie Collaboration Agreement under specified patents licensed to the Company by Penn. The AbbVie Sublicense Agreement became effective contemporaneously with the AbbVie Collaboration Agreement in November 2021 and is coterminous with the AbbVie Collaboration Agreement. The Company evaluated its various commitments under the AbbVie Collaboration Agreement and identified the following distinct units of account: (i) delivery of an intellectual property license for the rights to develop and commercialize ABBV-RGX-314 globally, (ii) development, manufacturing and commercialization activities for ABBV-RGX-314 in the United States, and (iii) manufacturing of commercial supply for sales of ABBV-RGX-314 outside the United States, if requested by AbbVie. In determining the distinct units of account, the Company concluded that the license granted to AbbVie to develop and commercialize ABBV-RGX-314 is distinct from the other goods and services promised under the agreement, as AbbVie can benefit from the license on a standalone basis and, based on the stage of development of ABBV-RGX-314, the underlying licensed products and know-how are not expected to be significantly modified as a result of other goods and services promised under the agreement. For each of the distinct units of account identified under the AbbVie Collaboration Agreement, the Company determined whether the transactions should be accounted for as a contract with a customer within the scope of ASC 606 or as a collaborative arrangement within the scope of ASC 808. The Company concluded that the units of account for the delivery of the functional intellectual property license and the manufacturing of commercial supply for sales of ABBV-RGX-314 outside the United States should be accounted for as revenue under ASC 606, as AbbVie is deemed to be a customer for these transactions. The Company concluded that the unit of account for development, manufacturing and commercialization activities for ABBV-RGX-314 in the United States should be accounted for as a collaborative arrangement under ASC 808, as these represent joint operating activities for which the Company and AbbVie are both active participants and exposed to significant risks and rewards dependent on the commercial success of such activities. The Company applied the requirements of ASC 606 to the AbbVie Collaboration Agreement for the units of account in which AbbVie was deemed to be a customer. The Company determined that there is only one material performance obligation under the agreement for the delivery of the intellectual property license to develop and commercialize ABBV-RGX-314 globally. The intellectual property licensed to AbbVie includes the rights to certain patents, data, know-how and other rights developed and owned by the Company, as well as other intellectual property rights exclusively licensed by the Company from various third parties. The Company evaluated options granted to AbbVie under the agreement and determined that the options do not represent material rights, and therefore are not considered separate performance obligations under the current contract. Specifically, the Company concluded that the option granted to AbbVie to purchase commercial supply of ABBV-RGX-314 from the Company for a portion of sales outside the United States does not convey a material right, as the option is not priced at an incremental discount to the standalone selling price of the underlying goods and services. Additionally, the Company identified various promises under the AbbVie Collaboration Agreement which were determined to be immaterial in the context of the contract and will not be accounted for as separate performance obligations. As of December 31, 2023 and 2022, the transaction price of the AbbVie Collaboration Agreement was $ 370.0 million, which consisted solely of the up-front payment received from AbbVie in November 2021. The $ 370.0 million transaction price was fully recognized as revenue upon the delivery of the license to AbbVie in November 2021. Variable consideration under the AbbVie Collaboration Agreement, which has been excluded from the transaction price, includes $ 562.5 million in payments for development milestones that have not yet been achieved and were not considered probable of achievement. Additionally, the transaction price excludes sales-based milestone payments of $ 820.0 million and royalties on net sales of ABBV-RGX-314 outside the United States. Development milestones will be added to the transaction price and recognized as revenue upon achievement, or if deemed probable of achievement. In accordance with the sale- or usage-based royalty exception under ASC 606, royalties on net sales and sales-based milestones will be recognized as revenue in the period the underlying sales occur or milestones are achieved. There were no changes in the transaction price of the AbbVie Collaboration Agreement during the years ended December 31, 2023 and 2022. The Company applied the requirements of ASC 808 to the AbbVie Collaboration Agreement for the units of account which were deemed to be a collaborative arrangement. Both the Company and AbbVie will perform various activities related to the development, manufacturing and commercialization of ABBV-RGX-314 in the United States. Development costs are shared between the parties in accordance with the terms of the AbbVie Collaboration Agreement, and the parties will share equally in the net profits and losses derived from sales of ABBV-RGX-314 in the United States. The Company accounts for payments to and from AbbVie for the sharing of development and commercialization costs in accordance with its accounting policy for collaborative arrangements. Amounts owed to AbbVie for the Company’s share of development costs or commercialization costs incurred by AbbVie are recorded as research and development expense or general and administrative expense, respectively, in the period the costs are incurred. 115 Table of Contents Amounts owed to the Company for AbbVie’s share of development costs or commercialization costs incurred by the Company are recorded as a reduction of research and development expense or general and administrative expense, respectively, in the period the costs are incurred. At the end of each reporting period, the Company records a net amount due to or from AbbVie as a result of the cost-sharing arrangement. As of December 31, 2023 and 2022, the Company had recorded $ 17.7 million and $ 6.2 million, respectively, due from AbbVie for net reimbursement of costs incurred for activities performed under AbbVie Collaboration Agreement, which was included in other current assets on the consolidated balance sheets. The Company recognized the following amounts under the AbbVie Collaboration Agreement (in thousands): Years Ended December 31, 2023 2022 2021 License and royalty revenue $ — $ — $ 370,000 Net cost reimbursement to (from) AbbVie included in: Research and development expense $ ( 74,209 ) $ ( 19,294 ) $ ( 5,866 ) General and administrative expense 768 1,531 — Total net cost reimbursement to (from) AbbVie $ ( 73,441 ) $ ( 17,763 ) $ ( 5,866 ) 11. Stock-based Compensation In September 2014, the Board of Directors adopted the 2014 Stock Plan (the 2014 Plan). In June 2015, the Board of Directors adopted the 2015 Equity Incentive Plan (the 2015 Plan), which became effective upon the Company’s initial public offering in September 2015. The 2015 Plan replaced the 2014 Plan, and as of the effective date of the 2015 Plan, no further awards may be issued under the 2014 Plan. Any options or awards outstanding under the 2014 Plan as of the effective date of the 2015 Plan remained outstanding and effective. The number of authorized shares under the 2015 Plan automatically increases annually on the first business day of each fiscal year, by the lesser of (i) 4 % of the total number of shares of common stock outstanding on December 31 of the prior year, or (ii) a number of common shares determined by the Board of Directors. As of December 31, 2023, the total number of shares of common stock authorized for issuance under the 2015 Plan and the 2014 Plan was 17,357,140 , of which 2,532,088 remained available for future grants under the 2015 Plan. An additional 1,761,849 shares were authorized for issuance under the 2015 Plan effective in January 2024. The 2014 Plan and 2015 Plan provide for the issuance of stock options, stock appreciation rights, restricted and unrestricted stock and unit awards, and performance cash awards to employees, members of the Board of Directors and consultants of the Company. Since the inception of the plans, the Company has issued only stock options and restricted stock units under the plans. Stock options under the 2014 Plan and 2015 Plan generally expire 10 years following the date of grant. Options typically vest over a four-year period, but vesting provisions can vary by award based on the discretion of the Board of Directors. Certain stock option awards granted by the Company may include performance conditions that must be achieved in order for vesting to occur. Stock options under the 2014 Plan and 2015 Plan have an exercise price at least equal to the estimated fair value of the Company’s common stock on the date of grant. Restricted stock units typically vest over a four-year period, but vesting provisions can vary by award based on the discretion of the Board of Directors. Upon vesting, restricted stock units are settled in common stock of the Company. Shares of common stock underlying awards previously issued under the 2014 Plan and 2015 Plan which are reacquired by the Company, withheld by the Company in payment of the purchase price, exercise price or withholding taxes, expired, cancelled due to forfeiture or otherwise terminated other than by exercise or settlement, are added to the number of shares of common stock available for issuance under the 2015 Plan. Shares available for issuance under the 2015 Plan may be either authorized but unissued shares of the Company’s common stock or common stock reacquired by the Company and held in treasury. The 2015 Plan expires in June 2025 , 10 years from the date it was adopted by the Board of Directors, unless earlier terminated. 116 Table of Contents Stock-based Compensation Expense The Company’s stock-based compensation expense by award type was as follows (in thousands): Years Ended December 31, 2023 2022 2021 Stock options $ 28,863 $ 34,444 $ 35,320 Restricted stock units 10,748 5,569 2,835 Employee stock purchase plan 656 775 653 $ 40,267 $ 40,788 $ 38,808 As of December 31, 2023, the Company had $ 59.4 million of unrecognized stock-based compensation expense related to stock options, restricted stock units and the 2015 Employee Stock Purchase Plan (the 2015 ESPP), which is expected to be recognized over a weighted-average period of 2.3 years. The Company recorded aggregate stock-based compensation expense in the consolidated statements of operations and comprehensive income (loss) as follows (in thousands): Years Ended December 31, 2023 2022 2021 Research and development $ 20,568 $ 21,368 $ 19,602 General and administrative 19,699 19,420 19,206 $ 40,267 $ 40,788 $ 38,808 Stock Options The following table summarizes stock option activity under the 2014 Plan and 2015 Plan (in thousands, except per share data): Weighted- average Weighted- Remaining average Contractual Aggregate Exercise Life Intrinsic Shares Price (Years) Value (a) Outstanding at December 31, 2022 7,668 $ 34.43 6.5 $ 15,783 Granted 1,715 $ 21.89 Exercised ( 223 ) $ 6.82 Cancelled or forfeited ( 579 ) $ 34.62 Outstanding at December 31, 2023 8,581 $ 32.62 6.2 $ 7,011 Exercisable at December 31, 2023 6,162 $ 34.61 5.3 $ 6,988 Vested and expected to vest at December 31, 2023 8,581 $ 32.62 6.2 $ 7,011 (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at the dates reported. The weighted-average grant date fair value per share of options granted during the years ended December 31, 2023, 2022 and 2021 was $ 13.66 , $ 19.43 and $ 26.01 , respectively. During the years ended December 31, 2023, 2022 and 2021, the total number of stock options exercised was 222,935 , 331,912 and 404,263 , respectively, resulting in total proceeds of $ 1.5 million, $ 2.8 million and $ 4.3 million, respectively. The total intrinsic value of options exercised during the years ended December 31, 2023, 2022 and 2021 was $ 2.9 million, $ 6.9 million and $ 11.9 million, respectively. 117 Table of Contents The fair values of options granted were estimated at each grant date using the Black-Scholes valuation model with the following weighted-average assumptions: Years Ended December 31, 2023 2022 2021 Expected volatility 65 % 66 % 68 % Expected term (years) 6.0 6.0 6.0 Risk-free interest rate 3.9 % 1.7 % 0.6 % Expected dividend yield 0.0 % 0.0 % 0.0 % Restricted Stock Units The following table summarizes restricted stock unit activity under the 2015 Plan (in thousands, except per share data): Weighted-average Grant Date Shares Fair Value Unvested balance at December 31, 2022 613 $ 35.41 Granted 1,039 $ 22.03 Vested ( 183 ) $ 35.09 Forfeited ( 160 ) $ 26.80 Unvested balance at December 31, 2023 1,309 $ 25.89 The total intrinsic value of restricted stock units vested during the years ended December 31, 2023 and 2022 was $ 3.9 million and $ 2.2 million, respectively. No restricted stock units vested during the year ended December 31, 2021. Employee Stock Purchase Plan In June 2015, the Board of Directors adopted the 2015 ESPP, which became effective upon the Company’s initial public offering in September 2015. The number of authorized shares reserved for issuance under the 2015 ESPP automatically increases on the first business day of each fiscal year by the lesser of (i) 1 % of the shares of common stock outstanding on the last business day of the prior fiscal year; or (ii) the number of shares determined by the Board of Directors. Unless otherwise determined by the administrator of the 2015 ESPP, two offering periods of six months’ duration will begin each year on January 1 and July 1. As of December 31, 2023, the total number of shares of common stock authorized for issuance under the 2015 ESPP was 1,426,994 , of which 1,018,364 remained available for future issuance. During the years ended December 31, 2023, 2022 and 2021 , 103,388 , 75,733 and 53,596 shares of common stock, respectively, were issued under the 2015 ESPP. 12. Retirement Plan The Company sponsors a defined-contribution retirement plan under Section 401(k) of the Internal Revenue Code (the 401(k) Plan). The 401(k) Plan covers all employees who meet defined minimum age and service requirements, and allows participants to defer a portion of their annual compensation. The Company matches employee deferrals up to a specified percentage of eligible compensation. For the years ended December 31, 2023, 2022 and 2021, the Company incurred expenses of $ 3.3 million, $ 3.0 million and $ 2.6 million, respectively, for matching contributions to the 401(k) Plan. 13. Income Taxes The components of income (loss) before income taxes were as follows (in thousands): Years Ended December 31, 2023 2022 2021 United States $ ( 263,574 ) $ ( 280,341 ) $ 141,303 Foreign ( 72 ) ( 64 ) ( 56 ) Total income (loss) before income taxes $ ( 263,646 ) $ ( 280,405 ) $ 141,247 118 Table of Contents The components of the provision for income tax expense (benefit) were as follows (in thousands): Years Ended December 31, 2023 2022 2021 Current: Federal $ — $ 3 $ 4,107 State ( 152 ) ( 87 ) 9,300 Foreign — — — Total current ( 152 ) ( 84 ) 13,407 Deferred: Federal — — — State — — — Foreign — — — Total deferred — — — Total income tax expense (benefit) $ ( 152 ) $ ( 84 ) $ 13,407 Beginning in 2022, the Tax Cuts and Jobs Act of 2017 (the TCJA) eliminated the option to deduct research and development expenses currently and requires taxpayers to amortize such costs over a period of five years for expenses incurred in the United States and a period of 15 years for expenses incurred outside the United States. This provision of the TCJA resulted in deferred tax assets of $ 107.3 million and $ 75.0 million as of December 31, 2023 and 2022, respectively, related to capitalized research and development expenses, net of amounts amortized during the periods. There was no material impact to the Company's current or deferred tax provision or operating cash flows during the years ended December 31, 2023 and 2022 as a result of this provision of the TCJA given the Company incurred net operating losses (NOLs) during the periods and has recorded a full valuation allowance against its deferred tax assets. The Inflation Reduction Act (the IRA) was enacted in August 2022 and contains revenue-raising provisions to include a book-income alternative minimum tax and an excise tax on stock buybacks, among other provisions. Based on the thresholds established by the IRA and a review of the Company’s transactions, the enactments of the IRA did not have an impact on the Company’s income tax provision for the years ended December 31, 2023 and 2022. The following table presents a reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate of 21 % to income tax expense (benefit) reported in the consolidated statements of operations and comprehensive income (loss) (in thousands): Years Ended December 31, 2023 2022 2021 Federal income tax expense (benefit) at statutory rate $ ( 55,366 ) $ ( 58,885 ) $ 29,662 State income tax expense (benefit), net of federal tax effect ( 14,330 ) ( 22,743 ) 9,183 Research and development credits ( 14,435 ) ( 16,844 ) ( 10,059 ) Stock-based compensation 3,348 3,216 755 Executive compensation 2,894 1,839 1,511 Other non-deductible expenses and reconciling items 569 241 329 Change in corporate tax rates 4,860 ( 3,636 ) 14,772 Change in valuation allowance 72,308 96,728 ( 32,746 ) Total income tax expense (benefit) $ ( 152 ) $ ( 84 ) $ 13,407 119 Table of Contents The significant components of the Company’s net deferred tax assets were as follows (in thousands): As of December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 61,929 $ 25,435 Research and development tax credits 77,178 62,545 Stock-based compensation 22,405 21,770 Lease liabilities 24,671 27,085 Liability related sale of future royalties 22,482 35,711 Capitalized research and development costs 107,302 74,989 Accruals and other 7,785 11,673 Total deferred tax assets before valuation allowance 323,752 259,208 Valuation allowance ( 280,455 ) ( 211,150 ) Total deferred tax assets 43,297 48,058 Deferred tax liabilities: Right-of-use assets ( 16,523 ) ( 18,571 ) Depreciation and amortization ( 26,774 ) ( 29,487 ) Total deferred tax liabilities ( 43,297 ) ( 48,058 ) Net deferred tax assets $ — $ — The Company evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets as of December 31, 2023 and 2022. Based on the Company’s history of operating losses, and other relevant facts and circumstances, the Company concluded that it was more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company provided a full valuation allowance for its net deferred tax assets as of December 31, 2023 and 2022. The valuation allowance increased by $ 69.3 million and $ 100.4 million during the years ended December 31, 2023 and 2022, respectively. The increases in the valuation allowance during the years ended December 31, 2023 and 2022 were due primarily to research and development expenses incurred during the periods which were capitalized for tax purposes, and federal and state NOLs and research and development tax credits generated during the periods. The following table presents the Company's U.S. federal and state NOL and tax credit carryforwards, net of unrecognized tax benefits, which may be available to offset future income tax liabilities (in thousands): As of December 31, 2023 Expiration Date (if not utilized) U.S. federal NOL carryforwards $ 212,711 Indefinite U.S. federal tax credit carryforwards $ 76,855 Various dates between 2037 and 2043 U.S. state NOL carryforwards $ 129,936 Indefinite U.S. state NOL carryforwards $ 129,129 Various dates between 2029 and 2043 U.S. state tax credit carryforwards $ 409 Various dates between 2029 and 2030 As of December 31, 2023 , the Company had U.S. federal and state research and development tax credit carryforwards of approximately $ 77.3 million, net of unrecognized tax benefits of $ 0.1 million, which may be available to reduce future income tax liabilities. The calculation of these credits requires assumptions to be made by the Company to estimate qualified research expenses. The Company conducts formal studies to document the qualified activities and expenses used to calculate these credits, however a portion of these credits may be subject to future studies which have not yet occurred, the results of which may result in an adjustment to the Company’s credit carryforwards. The Company accounts for uncertain tax positions in accordance with the requirements of ASC 740, and recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. As of December 31, 2023 and 2022 , the Company had total unrecognized tax benefits of $ 0.1 million and $ 0.1 million, respectively, which were reserved against its research and development tax credit carryforwards as uncertain tax positions. No reserve for uncertain tax positions has been placed against qualified expenses for which a study has not been conducted. However, a full valuation allowance has been provided against the net credit carryforwards and, if an adjustment is required upon the completion of the study, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance. If these unrecognized tax benefits were to be recognized, the impact would be offset by an adjustment to the valuation allowance, resulting in no impact on the Company’s effective tax rate. The Company does not expect that a significant portion of its unrecognized tax benefits will increase or decrease in the next 12 months as of December 31, 2023. 120 Table of Contents Under the provisions of the Internal Revenue Code, the Company’s NOL and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. NOL and tax credit carryforwards may be subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50 %, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has completed several financings since its inception which may have resulted in a change in control as defined by Sections 382 and 383 of the Internal Revenue Code, or could result in a change in control in the future. The Company and its subsidiaries file income tax returns in the United States, at the federal level and in various states, and in foreign jurisdictions. The U.S. federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2019 onward. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state tax authorities to the extent utilized in a future period. 14. Restructuring In November 2023, the Company implemented a strategic pipeline prioritization and corporate restructuring designed to reduce operating expenses and prioritize the development of ABBV-RGX-314, RGX-202 for the treatment of Duchenne muscular dystrophy, and RGX-121 for the treatment of Mucopolysaccharidosis Type II (MPS II), while pursuing strategic alternatives for the Company's other clinical stage programs. The restructuring included a reduction in workforce and other planned operating expenses, primarily in rare neurodegenerative disease development, early research and other general and administrative areas. As a result of the restructuring, the Company implemented a reduction in workforce of approximately 15 %, which was substantially completed in the fourth quarter of 2023. The Company recorded restructuring costs of $ 3.7 million during the year ended December 31, 2023, of which $ 3.0 million is included in research and development expense and $ 0.7 million is included in general administrative expense in the consolidated statements of operations and comprehensive income (loss). Restructuring costs primarily consisted of employee severance, continuing healthcare benefits and other employee-related costs. Restructuring costs associated with one-time termination benefits were recorded pursuant to ASC 420, while restructuring costs associated with ongoing benefit arrangements were recorded pursuant to ASC 712. The Company expects cash payments related to the restructuring costs to be completed by the fourth quarter of 2024. The following table presents the details of the Company's restructuring liability, which is included in accounts payable and accrued expenses and other current liabilities on the consolidated balance sheet as of December 31, 2023 (in thousands): Restructuring Liability Balance at December 31, 2022 $ — Restructuring charges 3,731 Cash payments ( 1,925 ) Balance at December 31, 2023 $ 1,806 15. Related Party Transactions From 2016 until June 2022, the Company was a party to professional services agreements with FOXKISER LLP (FOXKISER), an affiliate of certain stockholders of the Company and an affiliate of a member of the Company’s Board of Directors, pursuant to which the Company paid a fixed monthly fee in consideration for certain strategic services provided by FOXKISER. The agreement with FOXKISER was terminated effective June 2022. Expenses incurred under the agreement with FOXKISER for the years ended December 31, 2022 and 2021 were $ 2.4 million and $ 4.8 million, respectively, and were recorded as research and development expenses in the consolidated statements of operations and comprehensive income (loss). No expenses under the agreement with FOXKISER were incurred during the year ended December 31, 2023. 121 Table of Contents 16. Net Income (Loss) Per Share The computations of basic and diluted net income (loss) per share were as follows (in thousands, except per share data): Years Ended December 31, 2023 2022 2021 Basic net income (loss) per share: Net income (loss) $ ( 263,494 ) $ ( 280,321 ) $ 127,840 Shares used in computation: Weighted-average common shares outstanding 43,734 43,152 42,438 Basic net income (loss) per share $ ( 6.02 ) $ ( 6.50 ) $ 3.01 Diluted net income (loss) per share: Net income (loss) $ ( 263,494 ) $ ( 280,321 ) $ 127,840 Shares used in computation: Weighted-average common shares outstanding 43,734 43,152 42,438 Stock options — — 1,467 Restricted stock units — — 2 Employee stock purchase plan — — 6 Weighted-average diluted common shares 43,734 43,152 43,913 Diluted net income (loss) per share $ ( 6.02 ) $ ( 6.50 ) $ 2.91 For periods in which the Company incurred net losses, common stock equivalents were excluded from the calculation of diluted net loss per share as their effect would be anti-dilutive. Accordingly, basic and diluted net loss per share were the same for such periods. The following potentially dilutive common stock equivalents outstanding at the end of the period were excluded from the computations of weighted-average diluted common shares for the periods indicated as their effects would be anti-dilutive (in thousands): Years Ended December 31, 2023 2022 2021 Stock options issued and outstanding 8,581 7,668 4,939 Unvested restricted stock units outstanding 1,309 613 248 Employee stock purchase plan 27 30 — 9,917 8,311 5,187 17. Supplemental Disclosures Other Current Assets Other current assets consisted of the following (in thousands): As of December 31, 2023 2022 Net cost reimbursement due from collaborators $ 17,745 $ 6,294 Accrued interest on investments 1,551 2,210 Other 1,107 848 $ 20,403 $ 9,352 122 Table of Contents Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): As of December 31, 2023 2022 Accrued personnel costs $ 18,146 $ 18,071 Accrued sublicense fees and royalties 14,234 15,768 Accrued external research and development expenses 13,762 9,216 Accrued external general and administrative expenses 2,717 2,187 Accrued purchases of property and equipment 386 806 Other accrued expenses and current liabilities 458 746 $ 49,703 $ 46,794 Supplemental Disclosures of Non-cash Investing and Financing Activities Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities as of December 31, 2023 were $ 0.4 million, a net decrease of $ 2.1 million from December 31, 2022. Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities as of December 31, 2022 were $ 2.5 million, a net decrease of $ 7.5 million from December 31, 2021. Purchases of property and equipment included in accounts payable and accrued expenses and other current liabilities as of December 31, 2021 were $ 10.1 million, a net increase of $ 0.6 million from December 31, 2020. Proceeds due to the Company for sales of non-marketable equity securities included in other current assets as of December 31, 2021 were $ 0.6 million. No such amounts were recorded as of December 31, 2023 and 2022. Offering expenses for the ATM Program included in accounts payable and accrued expenses and other liabilities as of December 31, 2023 were less than $ 0.1 million. No such amounts were recorded as of December 31, 2022 and 2021. 123 Table of Contents EXHIBIT INDEX Incorporated by Reference Exhibit Number Description Form Exhibit Number Filing Date Filed or Furnished Herewith 1.1 ATM Equity Offering SM Sales Agreement, dated as of September 1, 2023, between BofA Securities, Inc. and REGENXBIO Inc. 8-K 1.1 9/1/23 3.1 Restated Certificate of Incorporation 8-K 3.1 6/7/21 3.2 Amended and Restated Bylaws 8-K 3.2 9/22/15 4.1 Specimen stock certificate evidencing the shares of common stock S-1 4.1 8/17/15 4.2 Description of Securities 10-K 4.2 3/1/22 10.1 Form of Indemnity Agreement for directors and officers S-1 10.1 8/17/15 10.2* 2014 Stock Plan, as amended S-1 10.2 8/17/15 10.3* 2015 Equity Incentive Plan S-1/A 10.3 9/15/15 10.4* Form of Restricted Stock Unit Award Agreement for the 2015 Equity Incentive Plan 10-K 10.4 3/1/21 10.5* Form of Stock Option Award Agreement for the 2015 Equity Incentive Plan 10-K 10.5 3/1/21 10.6* 2015 Employee Stock Purchase Plan S-1/A 10.4 9/8/15 10.7* Employment Agreement effective as of June 30, 2015 between the Registrant and Kenneth T. Mills S-1 10.5 8/17/15 10.8* Employment Agreement effective as of June 30, 2015 between the Registrant and Vittal Vasista S-1 10.7 8/17/15 10.9* Form of Employment Agreement for Executive Vice Presidents X 10.10* Compensation Program for Non-Employee Directors 10-Q 10.1 8/3/22 10.11* Management Cash Incentive Plan S-1 10.29 8/17/15 10.12† License Agreement effective February 24, 2009 between the Registrant and The Trustees of the University of Pennsylvania S-1/A 10.9 9/15/15 10.13† First Amendment to License Agreement dated March 6, 2009 between the Registrant and The Trustees of the University of Pennsylvania S-1 10.10 8/17/15 10.14† Second Amendment to License Agreement effective September 9, 2014 between the Registrant and The Trustees of the University of Pennsylvania S-1/A 10.11 9/15/15 10.15† Third Amendment to License Agreement effective April 29, 2016 between the Registrant and The Trustees of the University of Pennsylvania 10-Q/A 10.36 12/23/16 10.16† Fourth Amendment to License Agreement effective April 4, 2019 between the Registrant and The Trustees of the University of Pennsylvania 10-Q 10.2 5/7/19 10.17† Fifth Amendment to License Agreement effective September 11, 2020 between the Registrant and The Trustees of the University of Pennsylvania 10-Q 10.2 11/4/20 10.18† Letter Agreement dated March 21, 2022 between the Company and the Trustees of the University of Pennsylvania 10-Q 10.1 5/4/22 124 Table of Contents Incorporated by Reference Exhibit Number Description Form Exhibit Number Filing Date Filed or Furnished Herewith 10.19† License Agreement dated March 6, 2009 between the Registrant and SmithKline Beecham Corporation d/b/a GlaxoSmithKline S-1/A 10.12 9/15/15 10.20 Amendment to License Agreement dated April 15, 2009 between the Registrant and SmithKline Beecham Corporation d/b/a GlaxoSmithKline S-1 10.13 8/17/15 10.21† License Agreement dated March 21, 2014 between the Registrant and AveXis, Inc. S-1/A 10.16 9/15/15 10.22† First Amendment to License Agreement dated January 8, 2018 between the Registrant and AveXis, Inc. 10-K 10.24 3/6/18 10.23† Collaboration and License Agreement dated September 10, 2021 between the Registrant and AbbVie Global Enterprises Ltd. 10-Q 10.1 11/2/21 10.24 Lease dated March 6, 2015 between the Registrant and BMR-Medical Center Drive LLC S-1 10.26 8/17/15 10.25 First Amendment to Lease dated September 30, 2015 between the Registrant and BMR-Medical Center Drive LLC 10-K 10.31 3/3/16 10.26 Second Amendment to Lease dated November 23, 2015 between the Registrant and BMR-Medical Center Drive LLC 10-K 10.32 3/3/16 10.27 Third Amendment to Lease dated July 21, 2017 between the Registrant and BMR-Medical Center Drive LLC 10-Q 10.1 8/8/17 10.28 Fourth Amendment to Lease dated April 20, 2018 between the Registrant and BMR-Medical Center Drive LLC 10-Q 10.1 5/8/18 10.29 Fifth Amendment to Lease dated October 30, 2020 between the Registrant and ARE-Maryland No. 45, LLC, as successor in interest to BMR-Medical Center Drive LLC 10-Q 10.3 11/4/20 10.30 Lease dated November 1, 2018 between the Registrant and ARE-Maryland No. 24, LLC 10-Q 10.1 11/7/18 10.31 Letter Agreement to Lease dated April 12, 2019 between the Registrant and ARE-Maryland No. 24, LLC 10-Q 10.3 5/7/19 10.32 First Amendment to Lease dated April 23, 2019 between the Registrant and ARE-Maryland No. 24, LLC 10-Q 10.4 5/7/19 10.33 Second Amendment to Lease dated November 4, 2019 between the Registrant and ARE-Maryland No. 24, LLC 10-Q 10.1 11/5/19 10.34 Third Amendment to Lease dated October 30, 2020 between the Registrant and ARE-Maryland No. 24, LLC 10-Q 10.4 11/4/20 10.35† Royalty Purchase Agreement dated December 22, 2020 between the Registrant and entities managed by Healthcare Royalty Management, LLC 10-K 10.42 3/1/21 21.1 Subsidiaries of the Registrant X 23.1 Consent of PricewaterhouseCoopers LLP, independent registered accounting firm X 31.1 Certification of the Chief Executive Officer, as required by Section 302 of the Sarbanes-Oxley Act of 2002 X 31.2 Certification of the Chief Financial Officer as required by Section 302 of the Sarbanes-Oxley Act of 2002 X 125 Table of Contents Incorporated by Reference Exhibit Number Description Form Exhibit Number Filing Date Filed or Furnished Herewith 32.1 Certifications of the Chief Executive Officer and Chief Financial Officer as required by 18 U.S.C. 1350 X 97.1 Compensation Clawback Policy X 101 The following materials from the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 formatted in Inline XBRL (eXtensible Business Reporting Language): (i) Consolidated Balance Sheets (ii) Consolidated Statements of Operations and Comprehensive Income (Loss) (iii) Consolidated Statements of Stockholders’ Equity (iv) Consolidated Statements of Cash Flows (v) Notes to Consolidated Financial Statements X 104 The cover page from the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 formatted in Inline XBRL (included in Exhibit 101) * Management contract or compensatory plan or arrangement. † Portions of this exhibit have been omitted. The certifications attached as Exhibit 32.1 that accompany this Annual Report on Form 10-K are not deemed filed with the SEC and are not to be incorporated by reference into any filing of REGENXBIO Inc. under the Securities Act or the Exchange Act, whether made before or after the date of this Annual Report on Form 10-K, irrespective of any general incorporation language contained in such filing. 126 Table of Contents SIGNATURES Pursuant to the requirements of Section 13 and 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized on February 27, 2024. REGENXBIO INC. By: /s/ Kenneth T. Mills Kenneth T. Mills, President and Chief Executive Officer Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. Signature Title Date /s/ Kenneth T. Mills President, Chief Executive Officer and February 27, 2024 Kenneth T. Mills Director (Principal Executive Officer) /s/ Vittal Vasista Chief Financial Officer February 27, 2024 Vittal Vasista (Principal Financial and Accounting Officer) /s/ Allan M. Fox Chairman of the Board of Directors February 27, 2024 Allan M. Fox /s/ Jean Bennett Director February 27, 2024 Jean Bennett /s/ Alexandra Glucksmann Director February 27, 2024 Alexandra Glucksmann /s/ A.N. “Jerry” Karabelas Director February 27, 2024 A.N. “Jerry” Karabelas /s/ George Migausky Director February 27, 2024 George Migausky /s/ David C. Stump Director February 27, 2024 David C. Stump /s/ Daniel Tassé Director February 27, 2024 Daniel Tassé /s/ Jennifer Zachary Director February 27, 2024 Jennifer Zachary 127