Solid Biosciences Inc. 10-K

Item 9A. Controls and Procedures. Evaluation of Disclosure Controls and Procedures Our management, with the participation of our Chief Executive Officer and Chief Financial Officer (our principal executive officer and principal financial and accounting officer, respectively), evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2024. 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, or the Exchange Act, refers to 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 such 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 a company's management, including its principal executive and principal financial and accounting officers, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. In designing and evaluating our disclosure controls and procedures, management recognizes that disclosure controls and procedures, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the objectives of the disclosure controls and procedures are met. Additionally, in designing disclosure controls and procedures, our management necessarily was required to apply its judgment in evaluating the cost-benefit relationship of possible disclosure controls and procedures. The design of any system of controls also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions; over time, controls may become inadequate because of changes in conditions, or the degree of compliance with policies or procedures may deteriorate. Because of the inherent limitations in a control system, misstatements due to error or fraud may occur and not be detected. Based on the evaluation of our disclosure controls and procedures, our Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2024, our disclosure controls and procedures were designed and operating effectively. Management's Annual Report on Internal Control over Financial Reporting Our management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act. Our 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. 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. Management conducted an evaluation of the effectiveness of our internal control over financial reporting as of December 31, 2024 based on the framework in Internal Control-Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on that evaluation, management has concluded that the Company's internal control over financial reporting was effective as of December 31, 2024. As a non-accelerated filer and a “smaller reporting company”, as defined in Rule 12b-2 under the Exchange Act, our independent registered public accounting firm is not required to issue an attestation report on our internal control over financial reporting. Changes in Internal Control over Financial Reporting There have been 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 three months ended December 31, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. 105 Item 9B. Other Information. (b) Director and Officer Trading Arrangements None of our directors or officers adopted or terminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (as defined in Item 408(c) of Regulation S-K) during the fourth quarter of 2024. Item 9C. Disc losure Regarding Foreign Jurisdictions that Prevent Inspections. Not applicable. 106 PART III Item 10. Directors, Executive Officers and Corporate Governance. Set forth below are the names, ages and positions of our current executive officers and directors as of March 6, 2025. Name Age Position(s) held Executive Officers Alexander Cumbo 54 President, Chief Executive Officer and Director Gabriel Brooks, M.D. 48 Chief Medical Officer Jessie Hanrahan, Ph.D. 49 Chief Regulatory Officer Paul Herzich 47 Chief Technology Officer David Tyronne Howton 53 Chief Operating Officer and Secretary Kevin Tan 47 Chief Financial Officer and Treasurer Non-Employee Directors Ian F. Smith 59 Executive Chairman of the Board Martin Freed, M.D. 64 Director Ilan Ganot 51 Director Clare Kahn, Ph.D. 73 Director Georgia Keresty, Ph.D. 63 Director Sukumar Nagendran, M.D. 59 Director Adam Stone 45 Director Lynne Sullivan 58 Director Executive Officers Alexander Cumbo has served as our President and Chief Executive Officer and as a director since December 2022. Prior to that, Mr. Cumbo served as the President and Chief Executive Officer and as a director of AavantiBio, a gene therapy company, from October 2020 to December 2022, when we acquired AavantiBio. From January 2013 to October 2020, Mr. Cumbo held positions of increasing responsibility at Sarepta Therapeutics, Inc., or Sarepta, a precision genetic medicine company, ultimately serving as Executive Vice President, Chief Commercial Officer. From 2011 to 2013, Mr. Cumbo served as Vice President of Sales and Treatment Education for Vertex Pharmaceuticals Incorporated, or Vertex, a biotechnology company, launching Incivek, a treatment for hepatitis C, and from 2010 to 2011, he served as area director for Vertex. Prior to Vertex, Mr. Cumbo served in multiple commercial roles supporting the HIV, HBV and cardiovascular franchises at Gilead Sciences, Inc., a biopharmaceutical company. Mr. Cumbo has served on the Board of Directors of Verve Therapeutics, Inc. since June 2022. Mr. Cumbo previously served on the Board of Directors of RA Pharmaceuticals, Inc., a clinical stage biopharmaceutical company acquired by UCB, Brussels, from November 2018 to April 2020. Mr. Cumbo received a Bachelor of Science in Laboratory Technology from Auburn University. Mr. Cumbo is qualified to serve on our Board of Directors based on his extensive and broad range of experience in the biopharmaceutical industry and his deep knowledge of our company as our Chief Executive Officer. Gabriel Brooks, M.D. has served as our Chief Medical Officer since October 2023. Prior to that, Dr. Brooks served as Executive Director of Pfizer Inc., or Pfizer, a pharmaceutical company, from September 2020 to October 2023. Prior to joining Pfizer, Dr. Brooks served as Vice President of Research and Development for 4D Molecular Therapeutics, Inc., a biopharmaceutical company, from November 2018 to September 2020. Prior to joining 4D Molecular Therapeutics, Inc., Dr. Brooks served as Medical Director for GE HealthCare Technologies Inc., or GE Healthcare, a medical technology company. Prior to joining GE HealthCare, Dr. Brooks served as Associate Director of Clinical Research at Gilead Life Sciences, Inc., a biopharmaceutical company, from August 2015 to April 2017. Dr. Brooks received a Bachelor of Science in Biology from Carnegie Mellon University, a Doctor of Medicine from Cornell University, and a Master of Applied Sciences of Biostatistics and Epidemiology from the University of California, San Francisco. He completed his training in Internal Medicine at Johns Hopkins Hospital, Baltimore, and fellowships in general Cardiology and Advanced Imaging at the University of California, San Francisco. Jessie Hanrahan, Ph.D. has served as our Chief Regulatory Officer since December 2022. Prior to that, Dr. Hanrahan served as Chief Regulatory Officer of AavantiBio from May 2021 to December 2022. Prior to joining AavantiBio, Dr. Hanrahan served as the Vice President of Regulatory Science at bluebird bio, Inc., or bluebird, a biotechnology company, from February 2020 to May 2021 and Senior Director of Regulatory Science at bluebird from August 2016 to February 2020. Prior to joining bluebird, Dr. Hanrahan worked at Sanofi Genzyme, a biotechnology company, as Senior Manager of Regulatory Affairs from October 2009 to July 2016 and as Principal Medical Writer from July 2007 to October 2009. Prior to joining Sanofi Genzyme, Dr. Hanrahan served as a Medical Writer at Boston Scientific, a biomedical engineering firm, from May 107 2006 to July 2007. Dr. Hanrahan holds a Ph.D., M.S. and M.Ph. in Molecular, Cellular and Developmental Biology from Yale University. Dr. Hanrahan received a Bachelor of Arts in Biology and History from Mount Holyoke College. Paul Herzich has served as our Chief Technology Officer since December 2022. Prior to that, Mr. Herzich served as Chief Technology Officer of AavantiBio from April 2021 to December 2022. Before joining AavantiBio, Mr. Herzich served as Vice President of CMC at BridgeBio Pharma, Inc., or BridgeBio, a biopharmaceutical company, from August 2020 to April 2021. Previously, Mr. Herzich served as Head of Manufacturing Operations at BridgeBio from July 2019 to July 2020. Before joining BridgeBio, Mr. Herzich served as Senior Director of Manufacturing at LogicBio Therapeutics, Inc., a genetic medicine company, from January 2018 to July 2019. Additionally, Mr. Herzich served as Senior Manager and Director of cGMP Gene Therapy Manufacturing at Pfizer from August 2016 to January 2018. From July 2015 to August 2016, Mr. Herzich served as the head of TD Manufacturing at CSL Seqirus, a pharmaceutical company, after its acquisition of Novartis Vaccines and Diagnostics, Inc., where Mr. Herzich served in various roles of increasing responsibility from December 2007 to July 2015. Mr. Herzich holds a Master of Business Administration from North Carolina State University Poole College of Management and a Bachelor of Science in Biology from Rutgers University. David Tyronne Howton has served as our Chief Operating Officer since September 2023 and as our Secretary since December 2022. Mr. Howton previously served as our Chief Administrative Officer from December 2022 to September 2023 and as our General Counsel from December 2022 to July 2024. Prior to that, Mr. Howton served as the Chief Operating Officer and General Counsel of AavantiBio from March 2021 to December 2022. From November 2012 to December 2020, Mr. Howton served as Executive Vice President, General Counsel and Corporate Secretary at Sarepta. Prior to joining Sarepta, Mr. Howton served as the Senior Vice President and Chief Legal Officer and Chief Compliance Officer at Vertex. Prior to Vertex, Mr. Howton served in multiple legal roles at Genentech, Inc., a biotechnology company. Mr. Howton has served on the board of Make-A-Wish® Massachusetts and Rhode Island since March 2021. Mr. Howton received a Bachelor of Arts in Political Science from Yale University and a Juris Doctor from Northwestern University School of Law. Kevin Tan has served as our Chief Financial Officer and Treasurer since January 2023. Prior to that, Mr. Tan served as the Chief Financial Officer at Selecta Biosciences, Inc., or Selecta, a biopharmaceutical company, from September 2021 to November 2022. Prior to joining Selecta, Mr. Tan served as Treasurer at Sarepta from July 2020 to September 2021. Prior to becoming Treasurer at Sarepta, he served as Assistant Treasurer from May 2018 to June 2020. Before joining Sarepta, Mr. Tan worked as a freelance consultant from February 2017 to April 2018, providing independent financial advice and advisory services to individuals and private companies. From June 2012 to November 2016, Mr. Tan served as Senior Portfolio Manager — Public Market Investments at CPP Investments (f/k/a the Canada Pension Plan Investment Board). He has also served in various positions at Macquarie Capital (USA) Inc., Arrowhawk Capital Partners LLC, Lehman Brothers Inc. (subsequently acquired by Barclays Capital Inc.) and UBS Investment Bank. Mr. Tan holds a Bachelor of Commerce degree from Queen's University at Kingston, a Master of Engineering degree from The Graduate School at Princeton University, and a Master of Business Administration degree from the University of Chicago Booth School of Business. Mr. Tan is a Chartered Financial Analyst (CFA) charterholder. Non-Employee Directors Ian F. Smith is Executive Chairman of our Board of Directors and has served as a member of our Board of Directors since April 2020 and served as a consultant to us from February 2020 to December 2021. Mr. Smith is also the chairman of the Board of Directors of Rivus Pharmaceuticals, Inc. and iVexSol, Inc, and a member of the Board of Directors of Stoke Therapeutics, Inc., Foghorn Therapeutics Inc., Odyssey Therapeutics, Inc. and Alkeus Pharmaceuticals, Inc., which are all biotechnology companies. He is also a Senior Advisor to Bain Capital Life Sciences. Between 2001 and 2019, Mr. Smith served as Chief Financial Officer and then Chief Operating Officer at Vertex. He received a B.A. with honors in accounting and finance from Manchester Metropolitan University (UK). Mr. Smith is qualified to serve on our Board of Directors because of his more than 25 years of finance and broad operating experience for public companies in the biopharmaceutical industry. Martin Freed, M.D., F.A.C.P. has served as a member of our Board of Directors since June 2018. Dr. Freed has served as an independent consultant to several private pharmaceutical, biotechnology, and healthcare companies, specializing in clinical and general pharmaceutical development and clinical and regulatory strategy since February 2015. He co-founded and served as Chief Medical Officer of Civitas Therapeutics, Inc., a biopharmaceutical company acquired by Acorda Therapeutics, Inc., from December 2010 to October 2014, and as Senior Vice President, Clinical Development of Acorda Therapeutics, Inc. from October 2014 to January 2015. He has also served as Chief Medical Officer at Adnexus Therapeutics, Inc. (acquired by Bristol-Myers Squibb) and Vitae Pharmaceuticals, Inc. Dr. Freed spent nearly 14 years at GlaxoSmithKline and its predecessor, SmithKline Beecham Pharmaceuticals or SmithKline Beecham, where he served numerous roles including vice president, clinical development and medical affairs in the metabolism therapeutic area. Dr. Freed currently serves on the Board of Directors for Avilar Therapeutics, Inc. He previously served on the Board of Directors for Sojournix, Inc., Dicerna 108 Pharmaceuticals and Intekrin Therapeutics. Dr. Freed has been Board Certified in Internal Medicine, Nephrology and Clinical Pharmacology. He performed his internal medicine residency at Temple University Hospital and nephrology fellowship at Yale-New Haven Hospital. A Fellow of the American College of Physicians, Dr. Freed received a B.S. with distinction in biology from the University of Delaware and an M.D. from Pennsylvania State University's College of Medicine. Dr. Freed is qualified to serve on our Board of Directors because of his extensive leadership experience, his public company board experience and his experience working in the healthcare sector. Ilan Ganot is one of our founders and has served as a member of our Board of Directors since our inception in 2013. He also served as our Chief Executive Officer from 2013 to December 2022 and as our President from June 2018 to December 2022. From December 2022 to December 2023, Mr. Ganot assisted with the transition of his duties to Mr. Cumbo and provided other consulting and advisory services, as requested from time to time by us. Mr. Ganot is currently the Chief Executive Officer and a member of the Board of Alesta Therapeutics, a biotechnology company focused on the development of innovative therapies for rare diseases. Mr. Ganot is also a member of the Board of Directors of Minovia Therapeutics, a biotechnology company. Previously, Mr. Ganot served as an investment banker at JPMorgan Chase & Co., Nomura Securities Co., Ltd., and Lehman Brothers. Mr. Ganot received his MBA from London Business School and holds law and business degrees from Reichman University in Herzliya, Israel. Mr. Ganot also practiced corporate law in Israel and was a Captain in the Israeli Defense Forces. He is qualified to serve on our Board of Directors because of his personal dedication to improving treatments available for Duchenne patients, his extensive leadership experience and his extensive knowledge of our company based on his previous role as our Chief Executive Officer. Clare Kahn, Ph.D. has served as a member of our Board of Directors since March 2021 and has served as a consultant to us since June 2022. Dr. Kahn has served as R&D Strategy Officer at X-VAX Technology Inc., or X-VAX, a biotechnology company developing vaccines against pathogens acquired by mucosal infection such as herpes, since September 2019. She served as Chief Regulatory and Preclinical Development Officer at X-VAX from September 2018 to September 2019. Dr. Kahn has also been the president of Clare Kahn Pharma Consulting LLC, through which she provides consulting services on regulatory strategy since July 2016. Dr. Kahn was previously Vice President, Worldwide Regulatory Strategy, Global Innovative Pharma at Pfizer from January 2014 to June 2016 and Vice President, Worldwide Regulatory Strategy, Specialty Care Business at Pfizer from June 2010 to December 2013. Prior to Pfizer, she was Vice President of Regulatory Affairs for a variety of therapeutic areas including cardiovascular, metabolic, urology, oncology and vaccines at GlaxoSmithKline from 1999 to 2010. Dr. Kahn has a Ph.D. in Biochemical Pharmacology from The Royal Postgraduate Medical School, London and served as Assistant Professor of Pharmacology and of Pathology and Laboratory Medicine at The University of Pennsylvania from 1981 to 1985. Dr. Kahn is qualified to serve on our Board of Directors because of her extensive leadership experience and her experience working in the healthcare sector. Georgia Keresty, Ph.D., M.PH. has served as a member of our Board of Directors since March 2021. Dr. Keresty served as the Chief Operating Officer at Volnay Therapeutics, a biotechnology start-up company, from March 2023 to November 2024. Prior to this role, Dr. Keresty served as a senior advisor to Takeda R&D in 2021 and was their R&D Chief Operating Officer from 2017 to 2020. From 2003 to 2017 and from 1997 to 1999, she was an executive at Johnson & Johnson. From 1999 to 2003 and from 1983 to 1997, she held roles at Bristol-Myers Squibb Company and Novartis Pharmaceuticals Corporation or Novartis, respectively. Dr. Keresty holds BSc degrees in Chemical Engineering and Computer Science from Clarkson University and Ramapo College of New Jersey, an M.S. degree in Information Systems from Pace University, an MBA in Operations Management from Rutgers University, a Ph.D. in Operations Management from Rutgers University, and an MPH in Global Health Leadership from the University of Southern California. Dr. Keresty currently serves on the Board of Directors of Intellia Therapeutics, Inc. Dr. Keresty previously served on the Board of Directors of Aspen Technology, Inc. and Commissioning Agents, Inc. Dr. Keresty is also an NACD Board Leadership Fellow and Directorship Certified® since September 2020 and earned an NACD CERT Certificate in Cyber-Risk Oversight in January 2024. Dr. Keresty is qualified to serve on our Board of Directors because of her extensive leadership and governance experience, and her experience working in the healthcare sector. Sukumar Nagendran, M.D. has served as a member of our Board of Directors since September 2018. Since December 2022, Dr. Nagendran has served as President, Head of Research and Development at Taysha Gene Therapies, Inc., a gene therapy company, and he has served as a member of their Board of Directors since July 2020. Prior to that, he was the Chief Medical Officer and President of Research and Development at Jaguar Gene Therapy, or Jaguar, a biotechnology company, from February 2020 to December 2022. Prior to Jaguar, Dr. Nagendran was Chief Medical Officer and Senior Vice President of AveXis Inc., or AveXis, a clinical-stage gene therapy company, from September 2015 to July 2018, prior to the company's acquisition by Novartis. Prior to AveXis, Dr. Nagendran was Vice President of Medical Affairs of Quest Diagnostics, a provider of diagnostic information services, from March 2013 to September 2015. Prior to Quest Diagnostics, Dr. Nagendran held key leadership positions at Pfizer, Novartis, Daiichi Sankyo, and Reata Pharmaceuticals. Prior to moving to the biotech industry, Dr. Nagendran practiced internal medicine, with a focus on diabetes and cardiovascular disease. He is a Mayo Alumni Laureate and founding member of the Robert Wood Johnson Legacy Society. He is also the sponsor for the 109 Fonseca-Nagendran Scholar award at the American Diabetes Association to enhance research in minority populations. Dr. Nagendran currently serves on the Board of Directors of SalioGen Therapeutics. Dr. Nagendran received his undergraduate degree in Biochemistry from Rutgers University and his M.D. from Rutgers Medical School and trained in Internal Medicine at Mayo Clinic, Rochester. Dr. Nagendran is qualified to serve on our Board of Directors because of his extensive leadership experience and his experience working in the healthcare sector Adam Stone has served as a member of our Board of Directors since November 2015. Mr. Stone is currently the Chief Investment Officer of Perceptive Advisors, a life sciences focused investing firm, where he has worked since 2006. Since July 2021 and February 2021, respectively, Mr. Stone has served as a director and Chief Executive Officer of ARYA Sciences Acquisition Corp V and ARYA Sciences Acquisition Corp IV. Mr. Stone is currently a member of the Board of Directors of Immatics N.V., a public biopharmaceutical company, and LianBio and Xontogency LLC, both private companies, and he previously served as a member of the Board of Directors of Renovia Inc. and Prometheus Biosciences, Inc. Mr. Stone received a B.A. in molecular biology from Princeton University. Mr. Stone is qualified to serve on our Board of Directors because of his extensive experience developing early-stage biotech and healthcare companies. Lynne Sullivan has served as a member of our Board of Directors since November 2015. Ms. Sullivan has served as the Chief Financial Officer for UNITY Biotechnology, Inc., a biotechnology company, since August 2020. Prior to that, Ms. Sullivan served as the Chief Financial Officer for Compass Therapeutics, LLC, or Compass, a biotechnology company, from December 2018 to August 2019. Prior to Compass, Ms. Sullivan served as Biogen Inc.'s senior vice president of Finance from 2016 to December 2018, where she also served as vice president of Tax and Corporate Finance from February 2015 to March 2016 and vice president of Tax from April 2008 to February 2015. Ms. Sullivan is currently a member of the Board of Directors of Inozyme Pharma, Inc., a public biopharmaceutical company. She previously served as a member of the Board of Directors of BiomX Inc. She received an M.S. in Taxation from Bentley University and a B.S.B.A. from Suffolk University. Ms. Sullivan was a Certified Public Accountant for over 20 years. Ms. Sullivan is qualified to serve on our Board of Directors because of her extensive experience in public accounting and financial expertise and her experience working in the healthcare sector. Composition of the Board of Directors Our board of directors currently consists of nine members divided into three classes, with members of each class holding office for staggered three-year terms. There are currently two Class I directors (Alexander Cumbo and Sukumar Nagendran), whose terms expire at the 2025 annual meeting of stockholders; three Class II directors (Clare Kahn, Adam Stone and Lynne Sullivan), whose terms expire at the 2026 annual meeting of stockholders; and four Class III directors (Martin Freed, Ilan Ganot, Georgia Keresty and Ian Smith) whose terms expire at the 2027 annual meeting of stockholders (in all cases subject to the election and qualification of their successors or to their earlier death, resignation or removal). Delinquent Section 16(a) Reports Section 16(a) of the Exchange Act requires our directors and executive officers and holders of more than 10% of our common stock to file with the SEC initial reports of ownership and reports of changes in ownership of our common stock and other equity securities. Based solely on a review of our records and representations made by the persons required to file these reports, we believe all directors, executive officers, and 10% owners timely filed all reports regarding transactions in our securities required to be filed by Section 16(a) under the Exchange Act for the fiscal year ended December 31, 2024, with the exception of a Form 4 filed by Adam Stone on November 19, 2024 to report the grant of stock options on June 11, 2024. Audit Committee The members of our audit committee are Ms. Sullivan, Dr. Keresty and Mr. Stone, with Ms. Sullivan serving as chair of the audit committee. Our Board of Directors has determined that each of these individuals meets the independence requirements of the Sarbanes-Oxley Act, Rule 10A-3 under the Exchange Act, and the applicable listing standards of Nasdaq. Each member of our audit committee can read and understand fundamental financial statements in accordance with Nasdaq audit committee requirements. In arriving at this determination, the Board of Directors has examined each audit committee member’s employment and other experience. Our Board of Directors has determined that Ms. Sullivan qualifies as an audit committee financial expert within the meaning of SEC regulations and meets the financial sophistication requirements of the Nasdaq listing rules. In making this determination, our Board of Directors has considered Ms. Sullivan’s formal education and previous and current experience in financial roles. Both our independent registered public accounting firm and management periodically meet privately with our audit committee. Our audit committee met four times during fiscal year 2024. 110 Our audit committee’s responsibilities include, among other things: • appointing, approving the compensation of, and assessing the independence of our registered public accounting firm; • overseeing the work of our independent registered public accounting firm, including through the receipt and consideration of reports from that firm; • reviewing and discussing with management and our independent registered public accounting firm our annual and quarterly financial statements and related disclosures; • monitoring our internal control over financial reporting, disclosure controls and procedures and Code of Conduct; • overseeing our risk assessment and risk management policies; • overseeing cybersecurity risks; • establishing procedures for the receipt and retention of accounting related complaints and concerns; • meeting independently with our internal auditing staff, if any, our independent registered public accounting firm and management; • reviewing and approving or ratifying any related person transactions; • reviewing on a periodic basis our investment policy; and • preparing the audit committee report required by SEC rules. We believe that the composition and functioning of our audit committee complies with all applicable requirements of the Sarbanes-Oxley Act and all applicable SEC and Nasdaq rules and regulations. Code of Conduct We have adopted a Code of Business Conduct and Ethics, or the Code of Conduct, that applies to our directors, executive officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. The Code of Conduct is available on the “Governance & Financials” section of the “Investors & Media” page of our website www.solidbio.com. Our Board of Directors and the audit committee of our Board of Directors are responsible for overseeing the Code of Conduct. We intend to post on our website all disclosures that are required by law or the listing standards of Nasdaq concerning any amendments to, or waivers of, any provision of the Code of Conduct. Insider Trading Policy We have adopted an Insider Trading Policy governing the purchase, sale and/or other dispositions of our securities by our directors, officers, employees and other covered persons. We believe the Insider Trading Policy is reasonably designed to promote compliance with insider trading laws, rules and regulations, and Nasdaq listing standards. A copy of our Insider Trading Policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K for the fiscal year ended December 31, 2024. We do not engage in transactions in our securities while in possession of material nonpublic information concerning the company or our securities. Item 11. Executiv e Compensation. Compensation of our Named Executive Officers The following information describes the material elements of compensation awarded to, earned by or paid to each of our named executive officers, or the Named Executive Officers. Our Named Executive Officers for the year ended December 31, 2024 are: • Alexander Cumbo, our President and Chief Executive Officer; • Gabriel Brooks, our Chief Medical Officer; and • David Tyronne Howton, our Chief Operating Officer and Secretary. 111 2024 Summary Compensation Table The following table contains information about the compensation paid to or earned by each of our Named Executive Officers for the years ended December 31, 2024 and 2023. Salary Bonus Stock Awards Option Awards All Other Compensation Total Name and Principal Position Year ($) ($) (1) ($) (2) ($) (3) ($) (4) ($) Alexander Cumbo, President and Chief Executive Officer 2024 608,400 334,620 2,215,183 1,699,286 12,420 4,869,909 2023 585,000 321,750 — — 11,880 918,630 Gabriel Brooks, M.D., Chief Medical Officer 2024 468,000 187,200 785,378 618,887 11,907 2,071,372 David Tyronne Howton, Chief Operating Officer and Secretary 2024 473,200 189,280 1,057,038 831,076 12,420 2,563,014 2023 455,000 182,000 — — 11,880 648,880 (1) Except where noted otherwise, represents annual bonuses earned in the calendar year and paid to the Named Executive Officers after the completion of each calendar year at the discretion of our Board of Directors. (2) The amounts in this column represent the aggregate grant date fair value of the performance-based restricted stock unit awards, or PSUs, and restricted stock units, or RSUs, granted to the Named Executive Officers in the respective calendar years as computed in accordance with the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 718. The assumptions used in calculating the grant date fair value of the PSUs and RSUs are set forth in Note 9 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. The grant date fair value of the PSUs granted in 2024 included in this column reflects the value of the award based on the probable outcomes of performance conditions. The grant date fair value assuming the highest level of performance conditions being achieved for these PSUs is $5,088,807, $1,767,764, and $2,383,403 for Mr. Cumbo, Dr. Brooks, and Mr. Howton, respectively. (3) The amounts in this column represent the aggregate grant date fair value of the options granted to the Named Executive Officers in the respective calendars years as computed in accordance with FASB ASC Topic 718. The assumptions used in calculating the grant date fair value of the options are set forth in Note 9 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. (4) Reflects a matching contribution under our 401(k) plan. Narrative Disclosure to Summary Compensation Table Base Salary . We use base salaries to recognize the experience, skills, knowledge and responsibilities required of all our employees, including our Named Executive Officers. None of our Named Executive Officers is currently party to an employment agreement or other agreement or arrangement that provides for automatic or scheduled increases in base salary. In 2024, the annualized base salaries of our Named Executive Officers were as follows: $608,400 for Mr. Cumbo, $468,000 for Dr. Brooks and $473,200 for Mr. Howton. For 2025, our Board of Directors increased the base salary amount for Mr. Cumbo to $650,900, for Dr. Brooks to $502,100 and for Mr. Howton to $513,400. Annual Bonus. Our Board of Directors may, in its discretion, award bonuses to our Named Executive Officers from time to time. Our employment agreements with our Named Executive Officers provide that they will be eligible for annual performance-based bonuses up to a specified percentage of their salary, subject to approval by our Board of Directors. Performance-based bonuses, which are calculated as a percentage of base salary, are designed to motivate our employees to achieve annual goals based on our strategic, financial and operating performance objectives. From time to time, our Board of Directors has approved discretionary annual cash bonuses to our Named Executive Officers with respect to their prior year performance. With respect to 2024, our Board of Directors awarded a discretionary bonus of $334,620 to Mr. Cumbo, $187,200 to Dr. Brooks and $189,280 to Mr. Howton, which in each case equaled 100% of their respective target bonuses for 2024. 112 With respect to fiscal year 2025 performance, Mr. Cumbo, Dr. Brooks and Mr. Howton are eligible for annual discretionary bonuses of up to 60%, 45% and 45% of their 2025 annual base salary, respectively. Equity Incentives. Although we do not have a formal policy with respect to the grant of equity incentive awards to our executive officers, or any formal equity ownership guidelines applicable to them, we believe that equity grants provide our executives with a strong link to our long-term performance, create an ownership culture and help to align the interests of our executives and our stockholders. In addition, we believe that equity grants with a time-based vesting feature promote executive retention because this feature incentivizes our executive officers to remain in our employment during the vesting period. Accordingly, our Board of Directors and compensation committee periodically review the equity incentive compensation of our Named Executive Officers and from time to time may grant equity incentive awards to them in the form of stock options or RSUs with time-based and/or performance-based vesting conditions. In February 2024, we granted options to purchase 240,250, 87,500 and 117,500 shares of our common stock to Mr. Cumbo, Dr. Brooks and Mr. Howton, respectively, and RSUs with respect to 120,125, 43,750 and 58,750 shares of our common stock to Mr. Cumbo, Dr. Brooks and Mr. Howton, respectively. The options vest with respect to 25% of the shares underlying the options on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the option monthly thereafter through the fourth anniversary of the grant date. The RSUs vest in equal annual installments over a term of four years from the date of grant. In June 2024, we granted PSUs with respect to 677,604, 235,389, and 317,365 shares of our common stock to Mr. Cumbo, Dr. Brooks and Mr. Howton, respectively. The PSUs provide for the vesting of 25% of the target number of underlying units granted upon the achievement of each of four independent performance milestones predetermined by the Board of Directors, or the Performance Milestones, subject to continued service with us, or the Approval Conditions. The Performance Milestones are tied to the achievement of certain business objectives and are non-market and non-financial in nature. The Board of Directors will determine that all Approval Conditions have been satisfied and the number of units that will ultimately vest on the 2026 Evaluation Date, which will occur in the first quarter of 2026, and the 2027 Evaluation Date, which will occur in the first quarter of 2027. A maximum of 25% of the target number of PSUs may vest at the 2026 Evaluation Date and the percentage of the target number of PSUs allocable to any Performance Milestone that has not been achieved on or prior to the 2027 Evaluation Date shall be cancelled. In January 2025, we granted RSUs with respect to 401,600, 112,900, and 169,100 shares of our common stock to Mr. Cumbo, Mr. Brooks, and Mr. Howton respectively. The RSUs vest in equal annual installments over four years from the date of grant. Our employees and executives are eligible to receive stock options and other stock-based awards pursuant to our Amended and Restated 2020 Equity Incentive Plan, or the 2020 Plan. We use equity awards to compensate our executive officers in the form of initial grants in connection with the commencement of employment and also at various times, often but not necessarily annually. None of our executive officers is currently party to an employment agreement that provides for an automatic award of stock options, RSUs or PSUs. We have granted stock options and RSUs to our executive officers with time-based vesting. The options that we have granted to our executive officers typically become exercisable as to 25% of the shares underlying the option on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the option monthly thereafter through the fourth anniversary of the grant date. The RSUs that we have granted to our executive officers typically become exercisable as to 25% of the shares underlying the RSU on the first anniversary of the grant date and as to an additional 25% of the original number of shares underlying the RSU annually thereafter. In 2024, we also granted to our executive officers the PSUs as described above. Vesting rights cease upon termination of employment and exercise rights cease shortly after termination, except that vesting of certain equity awards is fully accelerated upon certain terminations in connection with a change of control and exercisability is extended in the case of death or disability. Prior to the exercise of an option or the vesting of an RSU or PSU, the holder has no rights as a stockholder with respect to the shares subject to such option or with respect to the RSUs or PSUs, including no voting rights and no right to receive dividends or dividend equivalents. The exercise price of all stock options granted after the closing of our initial public offering is equal to the fair market value of shares of our common stock on the date of grant, which is determined by reference to the closing market price of our common stock on The Nasdaq Global Select Market on the date of grant. Employment and Other Agreements We have entered into employment agreements with each of our executive officers. The employment agreements set forth the terms of the executive officers' compensation, including their base salary and annual performance bonus opportunity. In addition, the employment agreements provide that, subject to eligibility requirements under the plan documents governing such programs and our policies, the executive officers are entitled, on the same basis as our other employees, to participate in 113 and receive benefits under, any medical, vision and dental insurance policy maintained by us and we will pay, consistent with our then-current employee benefit policy, a portion of the cost of the premiums for any such insurance policy in which the executive officers elect to participate. Each executive officer is also eligible to receive paid vacation time, sick time, and Company holidays consistent with our policies as then in effect from time to time and equity awards at such times and on such terms and conditions as the Board of Directors may determine. Each executive officer's employment is at will. The employment agreements with Mr. Cumbo, Dr. Brooks and Mr. Howton are summarized below. On September 29, 2022, we entered into an employment agreement with each of Mr. Cumbo and Mr. Howton pursuant to which, effective as of December 2, 2022, Mr. Cumbo commenced employment as our President and Chief Executive Officer and Mr. Howton commenced employment as our Chief Administrative Officer, General Counsel and Secretary. Mr. Howton now serves as our Chief Operating Officer, and Secretary. On October 2, 2023, we entered into an employment agreement with Dr. Brooks, pursuant to which Dr. Brooks commenced employment as our Chief Medical Officer effective as of October 2, 2023. Pursuant to their respective employment agreements, Mr. Cumbo was initially entitled to an annual base salary of $585,000, Dr. Brooks was initially entitled to an annual base salary of $450,000 and Mr. Howton was initially entitled to an annual base salary of $455,000. Each of their base salaries for 2024 and 2025 is set forth above under “—Narrative Disclosure to Summary Compensation Table”. Each of their base salaries will be reviewed by our Board of Directors from time to time and is subject to change in the discretion of our Board of Directors. Mr. Cumbo, Dr. Brooks and Mr. Howton are also eligible to earn an annual performance bonus, with a target bonus amount equal to a specified percentage of their annual base salary, based upon our Board of Directors' assessment of their performance and our attainment of targeted goals as set by our Board of Directors in their sole discretion. The bonus may be in the form of cash, equity award(s), or a combination of cash and equity award(s). Pursuant to their employment agreements, Mr. Cumbo, Dr. Brooks and Mr. Howton are eligible for annual discretionary bonuses of up to 55%, 40% and 40% of their annual base salary, respectively. Mr. Cumbo, Dr. Brooks and Mr. Howton must be employed on the date that bonuses are paid in order to receive their respective bonus, provided that if such executive is terminated by us without cause (as "cause" is defined in their respective employment agreements) between January 1 of the year following the performance year and the date of payment, such executive will be entitled to the same bonus that he would have received had he remained employed through the payment date. In accordance with Mr. Cumbo's employment agreement, on December 2, 2022, we granted Mr. Cumbo an option, or the Cumbo Option , to purchase 228,900 shares of our common stock, at an exercise price per share equal to $6.77, which vested as to 25% of the shares underlying the Cumbo Option on the first anniversary of the grant date and vests as to an additional 1/48th of the total shares underlying the Cumbo Option upon his completion of each additional month of service over the 36-month period measured from the first anniversary of the grant date. We also granted Mr. Cumbo RSUs with respect to 114,449 shares of our common stock, or the Cumbo RSU, which vests as to 25% of the shares underlying the Cumbo RSU on each anniversary of December 2, 2022, subject to continued service. The Cumbo Option and the Cumbo RSU were granted as an inducement material to Mr. Cumbo's acceptance of employment with us in accordance with Nasdaq Listing Rule 5635(c)(4). In accordance with Dr. Howton’s employment agreement, on December 2, 2022, we granted Mr. Howton an option, or the Howton Option, to purchase 104,410 shares of our common stock, at an exercise price per share equal to $6.77, which vested as to 25% of the shares underlying the Howton Option on the first anniversary of the grant date and vests as to an additional 1/48th of the total shares underlying the Howton Option upon his completion of each additional month of service over the 36-month period measured from the first anniversary of the grant date. We also granted Mr. Howton RSUs with respect to 52,205 shares of our common stock, or the Howton RSU, which vests as to 25% of the shares underlying the Howton RSU on each anniversary of December 2, 2022, subject to continued service. The Howton Option and the Howton RSU were granted as an inducement material to Mr. Howton's acceptance of employment with us in accordance with Nasdaq Listing Rule 5635(c)(4). In accordance with Dr. Brook’s employment agreement, on October 18, 2023, we granted Dr. Brooks an option, or the Brooks Option, to purchase 78,000 shares of our common stock, at an exercise price per share equal to $2.15, which vested as to 25% of the shares underlying the Brooks Option on the first anniversary of the grant date and vests as to an additional 1/48th of the total shares underlying the Brooks Option upon his completion of each additional month of service over the 36-month period measured from the first anniversary of the grant date. We also granted Dr. Brooks RSUs with respect to 39,000 shares of our common stock, or the Brooks RSU, which vests as to 25% of the shares underlying the Brooks RSU on each anniversary of October 18, 2023, subject to continued service. Mr. Cumbo, Dr. Brooks and Mr. Howton are bound by proprietary rights, non-disclosure, developments, non-competition and non-solicitation obligations pursuant to the restrictive covenants provided for in their respective employment agreements. 114 Under these restrictive covenants, each executive agrees not to compete with us during his employment and for a period of one year after the termination of his employment, not to solicit our employees, consultants, or actual or prospective customers or business relations during his employment and for a period of one year after the termination of his employment, and to protect our confidential and proprietary information indefinitely. In addition, under these restrictive covenants, each executive agrees that we own all inventions that are developed by him during a specified period of time with respect to any inventions made by him that are related to his activities while employed by us. The employment of each of Mr. Cumbo, Dr. Brooks and Mr. Howton may be terminated as follows: (1) upon the death of the executive or at our election due to the executive's "disability" (as disability is defined in the applicable employment agreement); (2) at our election, with or without "cause” (as cause is defined in the applicable employment agreement); and (3) at such executive's election, with or without "good reason" (as good reason is defined in the applicable employment agreement). In the event of the termination of employment of Mr. Cumbo, Dr. Brooks or Mr. Howton by us without cause, or by such executive for good reason, prior to, or more than 12 months, in the case of Mr. Cumbo and Mr. Howton, and 18 months, in the case of Dr. Brooks, following a "change in control" (as change in control is defined in the applicable employment agreement), the executive is entitled to receive his base salary that has accrued and to which he is entitled as of the termination date, to the extent consistent with our policy, accrued but unused paid time off through and including the termination date, unreimbursed business expenses for which expenses the executive has timely submitted appropriate documentation, and other amounts or benefits to which the executive is entitled in accordance with the terms of the benefit plans then-sponsored by us, which we refer to collectively as the Accrued Obligations. In addition, subject to the executive's execution and nonrevocation of a release of claims in our favor, the executive is entitled to (1) continued payment of his base salary, in accordance with our regular payroll procedures, for a period of 12 months, (2) in the case of Dr. Brooks, a lump sum payment equal to 100% of his target bonus for the year in which his employment is terminated, or, if higher, his target bonus immediately prior to the change in control, prorated through his date of termination and (3) provided he is eligible for and timely elects to continue receiving group medical insurance under COBRA and the payments would not result in the violation of nondiscrimination requirements of applicable law, payment by us of the portion of health coverage premiums we pay for similarly-situated, active employees who receive the same type of coverage, for a period of up to 12 months following his date of termination. In the event of the termination of employment of Mr. Cumbo, Dr. Brooks or Mr. Howton by us without cause, or by such executive for good reason, within 12 months, in the case of Mr. Cumbo and Mr. Howton, and 18 months, in the case of Dr. Brooks, following a change in control, the executive is entitled to receive the Accrued Obligations. In addition, subject to the executive’s execution and nonrevocation of a release of claims in our favor, the executive is entitled to (1) continued payment of his base salary, in accordance with our regular payroll procedures, for a period of 18 months, in the case of Mr. Cumbo, and 12 months, in the case of Mr. Tan and Mr. Howton, (2) provided the executive is eligible for and timely elects to continue receiving group medical insurance under COBRA and the payments would not result in the violation of nondiscrimination requirements of applicable law, payment by us of the portion of health coverage premiums we pay for similarly-situated, active employees who receive the same type of coverage, for a period of up to 18 months, in the case of Mr. Cumbo, and 12 months, in the case of Dr. Brooks and Mr. Howton, following his date of termination, (3) a lump sum payment equal to 150%, in the case of Mr. Cumbo, and 100%, in the case of Dr. Brooks and Mr. Howton, of the executive's target bonus for the year in which his employment is terminated or, if higher, the executive's target bonus immediately prior to the change in control and (4) full vesting acceleration of any then-unvested equity awards that vest based solely based on the passage of time held by the executive, such that any such equity awards held by the executive become fully exercisable or non-forfeitable as of the termination date. If the employment of Mr. Cumbo, Dr. Brooks or Mr. Howton is terminated for any other reason, including as a result of his death or disability, for cause, or voluntarily by him without good reason, our obligations under such employment agreement cease immediately, and the executive is only entitled to receive the Accrued Obligations. 115 Outstanding Equity Awards at 2024 Fiscal Year-End The following table sets forth information regarding equity awards held by our Named Executive Officers as of December 31, 2024. Option Awards Stock Awards Name Number of securities underlying unexercised options (#) exercisable Number of securities underlying unexercised options (#) unexercisable Option exercise price ($) Option expiration date Number of shares of stock that have not vested (#) Market value of shares of stock that have not vested ($) (1) Equity incentive plan awards: number of unearned shares, units or other rights that have not vested (#) Equity incentive plan awards: market or payout value of unearned shares, units or other rights that have not vested ($)(1) Alexander Cumbo 114,452 114,448 (2) 6.77 12/02/2032 - 240,250 (3) 7.85 2/13/2034 57,225 (4) 228,900 (4) 120,125 (5) 480,500 (5) 169,401 (6) 677,604 (6) Gabriel Brooks 22,751 55,249 (7) 2.15 10/18/2033 - 87,500 (3) 7.85 2/13/2034 29,250 (8) 117,000 (8) 43,750 (5) 175,000 (5) 58,847 (6) 235,388 (6) David Tyronne Howton 52,208 52,202 (2) 6.77 12/02/2032 - 117,500 (3) 7.85 2/13/2034 26,103 (4) 104,412 (4) 58,750 (5) 235,000 (5) 79,341 (6) 317,364 (6) (1) Based on the $4.00 closing sale price of our common stock on December 31, 2024 as reported by the Nasdaq Global Select Market. (2) This option was granted on December 2, 2022 as an inducement grant. The option is subject to vesting with respect to 25% of the shares underlying the option on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the option monthly thereafter through the fourth anniversary of the grant date. (3) This option was granted on February 13, 2024 under the 2020 Plan and is subject to vesting with respect to 25% of the shares underlying the option on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the option monthly thereafter through the fourth anniversary of the grant date. (4) These RSUs were granted on December 2, 2022 as inducement grants. The RSUs vest in equal annual installments over a term of four years from the date of grant. (5) These RSUs were granted on February 13, 2024 under the 2020 Plan and vest in equal annual installments over a term of four years from the date of grant. (6) These PSUs were granted on June 11, 2024 under the 2020 Plan. The Performance Milestones are tied to the achievement of certain business objectives and are non-market and non-financial in nature. The Board of Directors will determine the number of units that will ultimately vest on the 2026 Evaluation Date, which will occur in the first quarter of 2026, and the 2027 Evaluation Date, which will occur in the first quarter of 2027. A maximum of 25% of the target 116 number of PSUs may vest at the 2026 Evaluation Date. The number in the table assumes 25% achievement on the 2026 Evaluation Date. For more information about the PSUs, see Narrative Disclosure to Summary Compensation Table in Item 11, “Executive Compensation” of this Annual Report on Form 10-K. (7) This option was granted on October 18, 2023 under the 2020 Plan and is subject to vesting with respect to 25% of the shares underlying the option on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the option monthly thereafter through the fourth anniversary of the grant date. (8) These RSUs were granted on October 18, 2023 under the 2020 Plan and vest in equal annual installments over a term of four years from the date of grant. Policies and Practices Related to the Grant of Equity Awards We grant equity awards, including stock options and/or restricted stock units, to our employees on an annual basis. We grant stock options to our directors on an annual basis. We may also grant stock options and/or restricted stock units to individuals upon hire or promotion or for retention purposes. We currently do not grant stock appreciation rights or similar option-like instruments. During the year ended December 31, 2024, neither the Board of Directors nor the compensation committee took material nonpublic information into account when determining the timing or terms of equity awards, nor did we time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation. While we do not have any policy or obligation that requires us to grant equity awards on specified dates, annual stock option and/or restricted stock unit grants to employees are typically approved in January or February of each year. During the year ended December 31, 2024, new hire equity grants were made by our Chief Executive Officer on the first business day of the month following such employee’s hire pursuant to delegated authority under our 2024 Inducement Stock Incentive Plan. Our Chief Executive Officer does not take into account material nonpublic information when determining the timing or terms of such equity grants. Under our non-employee director compensation program, our annual stock option grants to directors are granted on the date of our annual meeting of stockholders. During the year ended December 31, 2024, we did not grant stock options to any named executive officer during any period beginning four business days before and ending one business day after the filing of any Form 10-Q or Form 10-K, or the filing or furnishing of a Form 8-K that discloses material nonpublic information. Non-Employee Director Compensation Non-employee director compensation is set by our Board of Directors at the recommendation of our compensation committee. In 2024, the compensation committee retained Radford, an AON Hewitt company, to assist in assessing our non-employee director compensation program and provide recommendations with respect to the compensation program. Under our current director compensation program, we pay our non-employee directors a cash retainer for their service on the Board of Directors and for their service on each committee of which the director is a member. The chairs of each committee receive higher retainers for such service. These fees are payable in arrears in equal semi-annual installments not later than the 15th business day following the end of the second and fourth calendar quarters, provided that the amount of such payment will be prorated for any portion of such semi-annual period that the director is not serving on the Board of Directors, on such committee or in such position. The fees paid to non-employee directors for their service on the Board of Directors and for their service on each committee of the Board of Directors of which the director is a member are as follows: Member Annual Fee ($) Chairperson Incremental Annual Fee ($) Board of Directors 40,000 35,000 Audit Committee 7,500 7,500 Clinical Committee 7,500 7,500 Compensation Committee 5,000 5,000 Nominating and Corporate Governance Committee 4,000 4,000 We also reimburse our non-employee directors for reasonable out-of-pocket business expenses incurred in connection with the performance of their duties as directors, including travel expenses in connection with their attendance in person at our Board of Directors and committee meetings. 117 In addition, under our current director compensation program, each new non-employee director elected to our Board of Directors will receive an option to purchase 68,800 shares of our common stock under the 2020 Plan. Each of these options vests in equal annual installments over a three-year period measured from the date of grant, subject to the director’s continued service as a director. Further, on the date of our annual meeting of stockholders, each non-employee director that has served on our Board of Directors for at least six months prior to such annual meeting will receive an option to purchase 34,400 shares of our common stock under our 2020 Plan. Each of these options vests in full on the earlier to occur of the one-year anniversary of the grant date and immediately prior to our first annual meeting of stockholders occurring after the grant date, subject to the director’s continued service as a director. All options granted to our non-employee directors under our director compensation program will be issued at exercise prices equal to the fair market value of our common stock on the date of grant and will become exercisable in full in the event of a change in control. This program is intended to provide compensation for our non-employee directors in a manner that enables us to attract and retain outstanding director candidates and reflects the substantial time commitment necessary to oversee our affairs. We also seek to align the interests of our directors and our stockholders, and we have chosen to do so by compensating our non-employee directors with a mix of cash and equity-based compensation. The table below shows the compensation paid to our non-employee directors during 2024. Name Fees Earned or Paid in Cash ($) Option Awards ($) (1)(2) Stock Awards ($)(3) All Other Compensation ($) Total ($) Ian Smith 75,000 299,160 (4) 75,001 (5) — 449,161 Martin Freed, M.D., F.A.C.P. 60,000 224,204 (6) — — 284,204 Ilan Ganot 40,000 224,204 (6) — 241,145 (7) 505,349 Clare Kahn, Ph.D. 51,500 224,204 (6) — — 275,704 Georgia Keresty, Ph.D., M.PH. 49,247 224,204 (6) — — 273,451 Adam Koppel, M.D., Ph.D.(8) 17,901 46,803 — — 64,704 Sukumar Nagendran, M.D. 52,500 224,204 (6) — — 276,704 Rajeev Shah(8) 22,376 54,551 — — 76,927 Adam Stone 55,500 224,204 (6) — — 279,704 Lynne Sullivan 59,000 224,204 (6) — — 283,204 (1) The amounts in this column (i) represent the aggregate grant date fair value of the options granted to the non-employee directors as computed in accordance with FASB ASC Topic 718 and (ii) for Dr. Koppel and Mr. Shah, represents $46,803 and $54,551, respectively, of incremental fair value related to previously granted and vested options that were modified in August 2024, computed as of the modification date in accordance with FASB ASC Topic 718. The modification extended the exercise period for options that were vested as of the date of their resignation from our Board of Directors. The assumptions used in calculating the grant date fair value of the options are set forth in Note 9 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. (2) As of December 31, 2024, our non-employee directors held options to purchase shares of our common stock as follows: Mr. Smith: 203,906 shares; Dr. Freed: 65,430 shares; Mr. Ganot: 150,314 shares; Dr. Kahn: 62,432 shares; Dr. Keresty: 59,766 shares; Dr. Koppel: 21,966 shares; Dr. Nagendran: 63,765 shares; Mr. Shah: 28,032 shares; Mr. Stone: 62,432 shares; and Ms. Sullivan: 62,432 shares (3) The amount in this column represents the aggregate grant date fair value of the RSUs as computed in accordance with FASB ASC Topic 718. The assumptions used in calculating the grant date fair value of the award are set forth in Note 9 to our audited consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K. As of December 31, 2024, our non-employee directors held RSUs with respect to shares of our common stock as follows: Mr. Smith: 3,255 RSUs and Mr. Ganot: 7,767 RSUs. (4) Consists of (i) an option to purchase 15,112 shares of our common stock granted on January 3, 2024 in respect of his services as Executive Chairman and (ii) an option to purchase 34,400 shares of our common stock granted on June 11, 2024 in accordance with our non-employee director compensation program. (5) Consists of 13,021 RSUs granted on January 3, 2024 in respect of his services as Executive Chairman. (6) Consists of an option to purchase 34,400 shares of our common stock granted on June 11, 2024 in accordance with 118 our non-employee director compensation program. (7) Represents severance payments (representing continued payment of his former base salary) made to Mr. Ganot pursuant to the Ganot Transition Agreement (as defined below). For further information about the Ganot Consulting Agreement and Ganot Transition Agreement, see Item 13, “Certain Relationships and Related Transactions, and Director Independence” of this Annual Report on Form 10-K. (8) Resigned from our Board of Directors effective June 11, 2024. In respect of his services as Executive Chairman of our Board of Directors, on January 6, 2025, we granted Mr. Smith an option to purchase 22,148 shares of our common stock and 18,293 RSUs. Annie Ganot, who is the wife of Ilan Ganot and one of our co-founders, serves as our Vice President, Patient Advocacy. The compensation she receives in connection with such service is set forth in Item 13, “Certain Relationships and Related Transactions, and Director Independence” of this Annual Report on Form 10-K. During 2024, we did not provide any compensation to Mr. Cumbo, our President and Chief Executive Officer, for his service as a member of our Board of Directors. Mr. Cumbo’s compensation for his service as an executive officer is set forth above under “Compensation of our Named Executive Officers — 2024 Summary Compensation Table.” Compensation Committee Interlocks and Insider Participation None of the current members of our compensation committee has ever been an executive officer or employee of ours. None of our executive officers currently serves, or has served during the last completed fiscal year, on the compensation committee or board of directors of any other entity that has one or more executive officers serving as a member of our Board of Directors or compensation committee. Item 12. Security Ownership of Certain Beneficial Own ers and Management and Related Stockholder Matters. Security Ownership of Certain Beneficial Owners and Management The following table sets forth information regarding the beneficial ownership of our common stock as of February 24, 2025 by (i) each person whom we know to beneficially own more than 5% of our outstanding common stock, which we refer to as a 5% stockholder, (ii) each director, (iii) each Named Executive Officer and (iv) all current directors and executive officers as a group. Unless otherwise indicated, the address of each executive officer and director is c/o Solid Biosciences Inc., 500 Rutherford Avenue, 3rd Floor, Charlestown, Massachusetts 02129. The number of shares of common stock "beneficially owned" by each stockholder is determined under rules issued by the SEC regarding the beneficial ownership of securities. This information is not necessarily indicative of beneficial ownership for any other purpose. Under these rules, beneficial ownership of shares of our common stock includes (1) any shares as to which the person or entity has sole or shared voting power or investment power and (2) any shares as to which the person or entity has the right to acquire beneficial ownership within 60 days after February 24, 2025. The percentage of beneficial ownership in the table below is based on 76,516,805 shares of common stock deemed to be outstanding as of February 24, 2025. Unless otherwise indicated below, and subject to community property laws where applicable, to our knowledge, all persons named in the table have sole voting and investment power with respect to their shares of common stock. 119 Name of Beneficial Owner Number of Shares Beneficially Owned Percentage of Shares Beneficially Owned 5% Stockholders: Perceptive Life Sciences Master Fund Ltd. and affiliated entities(1) 11,934,678 15.59 % Entities affiliated with RA Capital Management, L.P.(2) 8,011,678 9.99 % Entities affiliated with Bain Capital Life Sciences Investors, LLC(3) 7,933,582 9.99 % Invus Public Equities, L.P. and affiliated entities (4) 7,415,905 9.69 % Commodore Capital Master LP(5) 5,825,000 7.61 % Entities managed by Vestal Point Capital, LP (6) 4,288,850 5.61 % Adage Capital Management, L.P.(7) 4,248,084 5.55 % Named Executive Officers and Directors: Alexander Cumbo(8) 264,314 * Gabriel Brooks(9) 77,585 * David Tyronne Howton(10) 119,969 * Ian Smith(11) 292,589 * Martin Freed(12) 34,614 * Ilan Ganot(13) 257,781 * Clare Kahn(14) 29,132 * Georgia Keresty(15) 25,366 * Sukumar Nagendran(16) 33,515 * Adam Stone(17) 28,032 * Lynne Sullivan(18) 28,032 * All current directors and executive officers as a group (14 persons)(19) 1,461,139 1.88 % * Less than 1 percent (1) Consists of (a) 11,833,539 shares held by Perceptive Life Sciences Master Fund, Ltd., (b) 73,107 shares held by Perceptive Xontogeny Venture Fund, L.P. and (c) 28,032 shares underlying options held by Adam Stone, a member of our Board of Directors, that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. Perceptive Advisors LLC is the investment manager to Perceptive Life Sciences Master Fund, Ltd. and may be deemed to beneficially own the securities directly held by Perceptive Life Sciences Master Fund, Ltd. Perceptive Xontogeny Venture GP, LLC is the investment manager to Perceptive Xontogeny Venture Fund, LP. Joseph Edelman is the managing member of Perceptive Advisors LLC and Perceptive Xontogeny Venture GP, LLC. Perceptive Advisors LLC, Perceptive Xontogeny Venture GP, LLC and Mr. Edelman may be deemed to beneficially own the shares held by Perceptive Life Sciences Master Fund, Ltd. and Perceptive Xontogeny Venture Fund, LP. The address of Perceptive is 51 Astor Place, 10th Floor, New York, New York 10003. Perceptive Life Sciences Master Fund, Ltd. reports that it holds shared voting and shared dispositive power with respect to 11,861,572 shares, Perceptive Xontogeny Venture Fund, L.P. reports that it holds shared voting and shared dispositive power with respect to 73,107 shares and Perceptive Advisors LLC reports that it holds shared voting and dispositive power with respect to 11,934,679 shares. Based on information set forth in a Schedule 13D/A filed with the SEC on February 21, 2025. (2) Consists of (a) 4,192,216 shares held by RA Capital Healthcare Fund, L.P., or RACHF, (b) 109,661 shares held by RA Capital Nexus Fund, L.P., or RACNF, (c) 28,569 shares held by a separately managed account, which is referred to, together with RACHF and RACNF, as the RA Capital Entities, (d) 28,032 shares of common stock underlying vested options held by Rajeev Shah, a former member of our Board of Directors, for the benefit of RA Capital Management, L.P., or RACM, that are exercisable as of February 24, 2025 and (e) pre-funded warrants exercisable for up to 3,722,085 shares of common stock held by RACHF. The pre-funded warrants contain a provision which precludes the exercise of the pre-funded warrants to the extent that, following exercise, RACHF, together with its affiliates and other attribution parties, would own more than 9.99% of our common stock outstanding. RACHF, together with its affiliates and other attribution parties, is currently prohibited from exercising the pre-funded to the extent that such exercise would result in beneficial ownership of more than 8,011,678 shares of common stock. RA Capital Healthcare Fund GP, LLC is the general partner of RACHF and RA Capital Nexus Fund GP, LLC is the general partner of RACNF. RACM is the investment manager for RACHF, RACNF and the separately managed account. The general partner of RACM is RA Capital Management GP, LLC, or RACM GP, of which Dr. Peter Kolchinsky and Mr. Shah are the managing members. Mr. Shah is a former member of our Board of Directors. RACM, RACM GP, Dr. Kolchinsky and Mr. Shah may be deemed to have voting and investment power over the shares held of record by RACHF, RACNF and the separately managed account. RACM, RACM GP, Dr. Kolchinsky and Mr. Shah expressly disclaim beneficial ownership over all shares held by RACHF, RACNF, the separately managed account and Mr. Shah, except to the extent of their pecuniary interest therein. The address for each of RACHF, RACNF and RACM is 200 Berkeley Street, 120 18th Floor, Boston, Massachusetts 02116. RACM reports that it may be deemed to share voting power and dispositive power with respect to the shares held by the RA Capital Entities. Based on information set forth in a Schedule 13D/A filed with the SEC on February 21, 2025. (3) Consists of (a) 528,660 shares held by BCLS SB Investco, LP., or BCLS SB, (b) an aggregate of 3,301,955 shares and pre-funded warrants exercisable for up to 6,444,170 shares of common stock held by BCLS II Investco, LP, or BCLS II Investco, (c) 267,257 shares held by Bain Capital Life Sciences Fund II, L.P., or BCLS Fund II, (d) 32,550 shares held by BCIP Life Sciences Associates, LP, or BCIPLS, and (e) 904,160 shares held by BCLS II Equity Opportunities, LP, or BCLS II EO, which is referred to, together with BCIPLS, BCLS SB, BCLS II Investco and BCLS Fund II, as the Bain Capital Life Sciences Entities. Bain Capital Life Sciences Investors, LLC (i) is the manager of Bain Capital Life Sciences Partners, LP, which is the general partner of BCLS SB, (ii) is the manager of Bain Capital Life Sciences Investors II, LLC, which is the general partner of BCLS Fund II, which is the managing member of BCLS II Investco (GP), LLC, which is the general partner of BCLS II Investco, and (iii) governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, Bain Capital Life Sciences Investors, LLC may be deemed to share voting and dispositive power with respect to the shares held by the Bain Capital Life Sciences Entities. BCLS II Investco is prohibited from exercising the pre-funded warrants to the extent that BCLS II Investco, together with its affiliates and other attribution parties, would, after such exercise, collectively beneficially own in excess of 9.99% of our outstanding common stock. BCLS II Investco, together with its affiliates and other attribution parties, is currently prohibited from exercising the pre-funded to the extent that such exercise would result in beneficial ownership of more than 7,933,582 shares of common stock. The address of the Bain Capital Life Sciences Entities is c/o Bain Capital Life Sciences, LP, 200 Clarendon Street, Boston, Massachusetts 02116. Based on information set forth in a Schedule 13D/A filed with the SEC on February 21, 2025. (4) Consists of 6,402,653 shares held by Invus Public Equities L.P., or Invus Public Equities, and 1,013,252 shares held by Avicenna Life Sci Master Fund LP, or Avicenna Fund. Invus Public Equities Advisors, LLC, or Invus PE Advisors, as the general partner of Invus Public Equities, controls Invus Public Equities and, accordingly, may be deemed to beneficially own the shares directly held by Invus Public Equities. Invus Global Management, LLC, or Global Management, as the managing member of Invus PE Advisors, controls Invus PE Advisors and, accordingly, may be deemed to beneficially own the shares that Invus PE Advisors may be deemed to beneficially own. Siren, L.L.C., or Siren, as the managing member of Global Management, controls Global Management and, accordingly, may be deemed to beneficially own the shares that Global Management may be deemed to beneficially own. Avicenna Life Sci Master GP LLC, or Avicenna GP, as the general partner of Avicenna Fund, controls Avicenna Fund and, accordingly, may be deemed to beneficially own the Shares beneficially held by Avicenna Fund. Ulys, as the managing member of Avicenna GP, controls Avicenna GP and, accordingly, may be deemed to beneficially own the shares that Avicenna GP may be deemed to beneficially own. Mr. Raymond Debbane, as the managing member of Siren and Ulys L.L.C., or Ulys, controls Siren and Ulys and, accordingly, may be deemed to beneficially own the shares that Siren and Ulys may be deemed to beneficially own. The address of Invus Public Equities and its affiliates is 750 Lexington Avenue, 30th Floor, New York, NY 10022. Based, in part, on information set forth in a Schedule 13G filed on February 12, 2025 and the shares purchased in the underwritten offering on February 19, 2025. (5) Consists of shares held by Commodore Capital Master LP, or Commodore. Commodore Capital LP is the investment manager of Commodore and may be deemed to beneficially own these shares. Michael Kramarz and Robert Egen Atkinson are the managing partners of Commodore Capital LP and exercise investment discretion with respect to these securities. The address of Commodore is 444 Madison Avenue, Floor 35, New York, New York 10022. Based on information set forth in a Schedule 13G filed with the SEC on February 25, 2025. (6) Consists of shares held by Vestal Point Capital, LP. The sole general partner of Vestal Point Master Fund, LP is Vestal Point Partners GP, LLC. The managing member of Vestal Point Partners GP, LLC is Ryan Wilder. The sole general partner of Vestal Point Capital, LP is Vestal Point Capital, LLC. The managing member of Vestal Point Capital, LLC is Mr. Wilder. As a result, Mr. Wilder may be deemed to have voting and investment power over the securities held by Vestal Point Master Fund, LP and the account separately managed by Vestal Point Capital, LP. Mr. Wilder disclaims beneficial ownership of such securities, except to the extent of his pecuniary interest therein. The address of these entities and Mr. Wilder is c/o Vestal Point Capital, LP, 632 Broadway, Suite 602, New York, NY 10012. Based, in part, on information set forth in a Schedule 13G filed on November 14, 2024 and the shares purchased in the underwritten offering on February 19, 2025. (7) Consists of shares held by Adage Capital Partners, L.P. Robert Atchinson and Phillip Gross are the managing members of Adage Capital Advisors, L.L.C., which is the managing member of Adage Capital Partners GP, L.L.C., which is the general partner of Adage Capital Partners, LP, and each such person or entity, as the case may be, has shared voting and/or dispositive power over the securities held by Adage Capital Partners, LP and may be deemed the beneficial owner of such shares, and each such person or entity, as the case may be, disclaims beneficial ownership of such securities except to the extent of their respective pecuniary interest therein. The address of Adage Capital Partners, LP, Adage Capital Advisors, L.L.C., Adage Capital Partners GP, L.L.C., Mr. Atchinson and Mr. Gross is c/o Adage 121 Capital Partners, L.P., 200 Clarendon St., 52nd Floor, Boston, MA 02116. Based on information set forth in a Form 4 filed with the SEC on February 19, 2025. (8) Consists of (a) 60,717 shares of common stock owned by Mr. Cumbo and (b) 203,597 shares of common stock underlying options held by Mr. Cumbo that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (9) Consists of (a) 22,812 shares of common stock owned by Dr. Brooks and (b) 54,773 shares of common stock underlying options held by Dr. Brooks that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (10) Consists of (a) 24,789 shares of common stock owned by Mr. Howton and (b) 95,180 shares of common stock underlying options held by Mr. Howton that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (11) Consists of (a) 112,972 shares of common stock owned by Mr. Smith, (b) 175,043 shares of common stock underlying options held by Mr. Smith that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date and (c) 4,574 shares of common stock underlying RSUs held by Mr. Smith that will vest within 60 days after such date. (12) Consists of (a) 3,584 shares of common stock owned by Dr. Freed and (b) 31,030 shares of common stock underlying options held by Dr. Freed that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (13) Consists of (a) 94,648 shares held by Mr. Ganot as an individual, (b) 4,042 shares held by Mr. Ganot and Ms. Ganot as joint tenants with right of survivorship, (c) 19,394 shares held by Mr. Adam Ganot and Ms. Ganot and their successors, as trustees for the Ilan Ganot 2017 Irrevocable Trust, (d) 108,147 shares of common stock underlying options held by Mr. Ganot that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date, (e) 14,839 shares held by Ms. Ganot, and (f) 16,711 shares of common stock underlying options held by Ms. Ganot that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date (14) Consists of (a) 1,100 shares of common stock owned by Dr. Kahn, and (b) 28,032 shares of common stock underlying options held by Dr. Kahn that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (15) Consists of 25,366 shares of common stock underlying options held by Dr. Keresty that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (16) Consists of (a) 4,150 shares of common stock owned by Dr. Nagendran and (b) 29,365 shares of common stock underlying options held by Dr. Nagendran that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (17) Consists of 28,032 shares of common stock underlying options held by Mr. Stone that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. Mr. Stone is Chief Investment Officer of Perceptive Advisors LLC. Mr. Stone disclaims beneficial ownership of the shares held by Perceptive. The address of Mr. Stone is 51 Astor Place, 10th Floor, New York, NY 10003. (18) Consists of 28,032 shares of common stock underlying options held by Ms. Sullivan that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date. (19) Includes (a) 1,023,599 shares of common stock underlying options that are exercisable as of February 24, 2025 or will become exercisable within 60 days after such date and (b) 4,574 shares of common stock underlying RSUs that will vest within 60 days after February 24, 2025. Securities Authorized for Issuance under Equity Compensation Plans The following table provides information about our equity compensation plans as of December 31, 2024. As of December 31, 2024, we had four equity compensation plans: our 2018 Omnibus Incentive Plan, our 2020 Plan, our Amended and Restated 2021 Employee Stock Purchase Plan, or the ESPP, each of which was approved by our stockholders, and our 2024 Inducement Stock Incentive Plan, which plan was not approved by our stockholders. We have also made inducement awards outside of our equity compensation plans to certain new hires, which awards were not approved by our stockholders. 122 Plan Category (a) Number of securities to be issued upon the exercise of outstanding options, warrants and rights (b) Weighted- average exercise price of outstanding options, warrants and rights (2) (c) Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column (a)) Equity compensation plans approved by security holders 5,227,045 (1) $ 22.84 663,969 (3)(4) Equity compensation plans not approved by security holders 1,346,489 (5) 6.91 599,933 Total 6,573,534 $ 18.22 1,263,902 (1) Reflects shares issuable upon exercise of options and settlement of RSUs and PSUs (assuming payout of PSUs at the maximum achievement level). (2) The weighted-average exercise price does not include RSUs and PSUs, which have no exercise price. (3) The number of shares of common stock reserved for issuance under the 2020 Plan will be increased on the first day of each fiscal year beginning with the fiscal year ended December 31, 2023 and ending in the fiscal year ending December 31, 2032, in an amount equal to the lesser of: (i) 5% of the outstanding shares of our common stock on the first day of the applicable fiscal year and (ii) an amount determined by our Board of Directors. On January 1, 2025, the shares of common stock reserved under the 2020 Plan were increased by 2,023,407 shares pursuant to the annual increase described above. (4) The number of shares of common stock reserved for issuance under the ESPP will be increased on the first day of each fiscal year beginning with the fiscal year ending December 31, 2024 and ending in the fiscal year ending December 31, 2033, in an amount equal to the lesser of: (i) 293,597 shares of common stock, (ii) 1% of the outstanding shares of our common stock on the first day of the applicable fiscal year and (iii) an amount determined by our Board of Directors. On January 1, 2025, the shares reserved under the ESPP were increased by 293,597 shares pursuant to the annual increase described above. (5) Represents inducement stock option and RSU awards granted to employees in accordance with Nasdaq Listing Rule 5635(c)(4), with an exercise price equal to the closing price of our common stock on the date of grant, for inducement stock option awards. This aggregate amount includes the following inducement awards made to our officers (as defined in Exchange Act Rule 16a-1(f)): Name Options(1) RSUs(2) Grant Date Alexander Cumbo, 228,900 114,449 12/2/2022 President, Chief Executive Officer and Director Kevin Tan, 90,000 45,000 1/9/2023 Chief Financial Officer and Treasurer David Tyronne Howton, 104,410 52,205 12/2/2022 Chief Operating Officer and Secretary Jessie Hanrahan, Ph.D., 94,899 47,449 12/2/2022 Chief Regulatory Officer Paul Herzich, 57,900 28,955 12/2/2022 Chief Technology Officer (1) Vests over a term of four years, with 25% of the original number of shares vesting on the first anniversary of the grant date and 2.0833% of the original number of shares monthly thereafter until the fourth such anniversary. (2) Vests over a term of four years, with 25% of the original number of shares vesting on each anniversary of the grant date until the fourth such anniversary. 123 Item 13. Certain Relationships and Related Transactions, and Director Independence. Transactions with Related Persons In addition to the executive officer and director compensation arrangements discussed in Item 11, “Executive Compensation” of this Annual Report on Form 10-K, the following describes transactions since January 1, 2023 to which we have been or will be a participant, in which the amount involved in the transaction exceeds the lesser of $120,000 or 1% of our total assets at year end for each of the last two completed fiscal years and in which any of our directors, executive officers or beneficial holders of more than 5% of any class of our capital stock, or any immediate family member of, or person sharing the household with, any of these individuals, had or will have a direct or indirect material interest. Amended and Restated Registration Rights Agreement We are party to an Amended and Restated Registration Rights Agreement, or the Registration Rights Agreement, dated March 29, 2017, with certain of our stockholders, or the Investors, which includes holders of more than 5% of our voting securities and entities affiliated with certain of our directors. The Registration Rights Agreement provides the Investors the right, subject to certain conditions, to demand that we file a registration statement or to request that their shares be covered by a registration statement that we are otherwise filing. February 2025 Underwritten Registered Offering On February 19, 2025, we closed an underwritten offering in which we issued and sold an aggregate of 35,739,810 shares of our common stock at a price per share of $4.03 and pre-funded warrants to purchase 13,888,340 shares of our common stock at a price per warrant of $4.029, before expenses and underwriting discounts and commissions. We received aggregate net proceeds of approximately $187.5 million, after deducting expenses and underwriting discounts and commissions. The number of shares that our holders of more than 5% of our voting securities purchased and the aggregate purchase price paid for such shares is set forth in the table below. Purchaser (1) Pre-Funded Warrants Purchased (#) Aggregate Purchase Price for Pre-Funded Warrants ($) Shares of Common Stock Purchased (#) Aggregate Purchase Price for Shares ($) BCLS II Investco, LP 6,444,170 25,963,561 1,000,000 4,030,000 Perceptive Life Sciences Master Fund Ltd. — — 5,000,000 20,150,000 RA Capital Healthcare Fund, LP 3,722,085 14,996,281 — — Adage Capital Partners, L.P. — — 2,481,400 10,000,042 Invus Public Equities, L.P. — — 3,722,100 15,000,063 Vestal Point Capital, LP — — 1,488,850 6,000,066 (1) See Item 12, “Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters” of this Annual Report on Form 10-K for more information about the shares held by the identified entities. January 2024 Private Placement On January 8, 2024, we entered into a securities purchase agreement with respect to the private placement of an aggregate of 16,973,103 shares of our common stock at a price of $5.53 per share, and, to one investor in lieu of shares, pre-funded warrants to purchase 2,712,478 shares of our common stock, at a price of $5.529 per pre-funded warrant. We received $103.7 million in aggregate net proceeds from the private placement, after deducting offering costs. The number of shares purchased by the holders of more than 5% of our voting securities at the time of the private placement and the aggregate purchase price paid for such shares is set forth in the table below. 124 Name (1) Shares of Common Stock Purchased (#) Purchase Price ($) Perceptive Life Sciences Master Fund Ltd. 3,410,713 18,861,243 Adage Capital Partners, L.P. 2,712,478 15,000,003 Deerfield Partners, L.P. 2,260,398 12,500,001 Invus Public Equities, L.P. 1,808,319 10,000,004 RA Capital Healthcare Fund, L.P. 904,160 5,000,005 BCLS II Equity Opportunities, LP 904,160 5,000,005 (1) See Item 12, “Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters” of this Annual Report on Form 10-K for more information about the shares held by the identified entities. Arrangements with Ian F. Smith Mr. Smith became our Executive Chairman, effective January 1, 2022. The compensation that we have paid to Mr. Smith in connection with his services as Executive Chairman and as our non-employee director is discussed above in Item 11, “Executive Compensation” of this Annual Report on Form 10-K. Arrangements with Ilan Ganot Mr. Ganot is a member of our Board of Directors and served as our President and Chief Executive Officer until December 2022. On September 29, 2022, we entered into an Executive Transition and Separation Agreement with Mr. Ganot, or the Ganot Transition Agreement, which became effective as of December 2, 2022, or the Separation Date. Pursuant to the Ganot Transition Agreement, Mr. Ganot was entitled to (1) continued payment of his base salary, in accordance with our regular payroll procedures, for a period of 18 months from the Separation Date (an aggregate of $868,050) and (2) provided he was eligible for and timely elected to continue receiving group medical insurance under COBRA and the payments would not result in the violation of nondiscrimination requirements of applicable law, payment by us of the portion of health coverage premiums we pay for similarly-situated, active employees who receive the same type of coverage, for a period of up to 18 months following the Separation Date. Mr. Ganot also received $477,427, less applicable taxes and withholdings, which is a lump sum payment equal to 150% of his target bonus for 2022. On September 29, 2022, we also entered into a Consulting Agreement with Mr. Ganot, or the Ganot Consulting Agreement, effective as of the Separation Date, pursuant to which Mr. Ganot assisted us with the transition of his duties to Mr. Cumbo and provided other consulting and advisory services, as requested from time to time by us. The Ganot Consulting Agreement expired by its terms in December 2023. Mr. Ganot was compensated at a rate of $20,833 per month for his services under the agreement for a total of $250,000. We employ Ms. Ganot, one of our co-founders and the wife of Ilan Ganot, as our Vice President, Patient Advocacy. For 2023 and 2024, Ms. Ganot received annual salary and bonus payments of $360,380 and $374,795, respectively. For 2025 we expect Ms. Ganot will receive annual salary and bonus payments of less than $475,000 in the aggregate. In January 2023, February 2024 and February 2025, we granted (i) an option to purchase 23,950 shares of our common stock and RSUs with respect to 11,975 shares of our common stock, (ii) RSUs with respect to 19,444 shares of our common stock and (iii) RSUs with respect to 60,000 shares of our common stock, respectively, to Ms. Ganot relating to her service as our Vice President, Patient Advocacy. The options vest over a term of four years, with 25% of the original number of shares vesting on the first anniversary of the date of grant and 2.0833% of the original number of shares on the first day of each calendar month thereafter until the fourth such anniversary. The RSUs vest in equal annual installments over a term of four years from the date of grant. For further information about the compensation received by Mr. Ganot in 2024, see “Non-Employee Director Compensation” in Item 11, “Executive Compensation” of this Annual Report on Form 10-K. Arrangements with Carl Morris Carl Morris served as our Chief Scientific Officer, Neuromuscular until July 14, 2023, or the Morris Separation Date. On May 22, 2023, we entered into an executive transition and separation agreement with Dr. Morris, or the Morris Transition and Separation Agreement. On the Morris Separation Date, we also entered into a consulting agreement, or the Morris Consulting Agreement, pursuant to which Dr. Morris assisted with the transition of his duties and provided other consulting and advisory services, as requested from time to time by us. Pursuant to the Morris Transition Separation Agreement, Dr. Morris was entitled to receive all unpaid base salary earned through the Morris Separation Date, any amounts for accrued unused paid time off to which he was entitled through such 125 date in accordance with our policy, and reimbursement of any properly incurred unreimbursed business expenses incurred through such date. In addition, contingent on his providing a release of claims, Dr. Morris was entitled to (1) severance equal to a year’s base salary, paid ratably over 12 months from the Morris Separation Date (an aggregate of $430,500), (2) provided he was eligible for and timely elected to continue receiving group health insurance under COBRA, payment by us of the portion of health coverage premiums that we pay for similarly-situated, active employees who receive the same type of coverage, for a period of up to 12 months following the Morris Separation Date, and (3) $172,200, less applicable taxes and withholdings, which is a lump sum payment equal to 100% of his target bonus for 2023. In January 2023, we granted options to purchase 95,100 shares of our common stock and RSUs with respect to 47,555 shares of our common stock to Dr. Morris. The options vested with respect to 25% of the shares underlying the options on the first anniversary of the grant date and as to an additional 2.0833% of the original number of shares underlying the options monthly thereafter through the fourth anniversary of the grant date. The RSUs vest in equal annual installments over four years from the date of grant. In consideration for services under the Morris Consulting Agreement, Dr. Morris’ then-outstanding equity awards continued to vest and remained exercisable in accordance with the applicable equity plans and award agreements. Arrangements with Danforth Advisors, LLC In November 2020, we entered into a consulting agreement with Danforth Advisors, LLC, or Danforth, an affiliate of Stephen DiPalma, our former interim chief financial officer who resigned in January 2023. Pursuant to the consulting agreement, Danforth provided us with the chief financial officer services of Mr. DiPalma, and continues to provide us other services, including financial planning, offering support and accounting services, in exchange for fees payable to Danforth based on hourly rates. We have paid Danforth approximately $2.8 million to date. The consulting agreement may be terminated by either party without cause upon 60 days’ prior written notice to the other party and with cause upon 30 days’ prior written notice to the other party. Indemnification Agreements We have entered into agreements to indemnify our directors and executive officers. These agreements require us, among other things, to indemnify these individuals for certain expenses (including attorneys' fees), judgments, fines and settlement amounts reasonably incurred by such persons in any action or proceeding, including any action by or in our right, on account of any services undertaken by any such person on behalf of our company or that person's status as a member of our Board of Directors to the maximum extent allowed under Delaware law. Policy for Approval of Related-Person Transactions We have adopted a written related-person transaction policy that sets forth our procedures for the identification, review, consideration and approval or ratification of any transaction, arrangement or relationship in which we are a participant, the amount involved exceeds $120,000 and one of our executive officers, directors, director nominees or 5% stockholders (or their immediate family members), each of whom we refer to as a "related person," has a direct or indirect material interest. If a related person proposes to enter into such a transaction, arrangement or relationship, which we refer to as a "related-person transaction," the related person must report the proposed related-person transaction to our general counsel. The policy calls for the proposed related-person transaction to be reviewed by and if deemed appropriate approved by, the audit committee of our Board of Directors. Whenever practicable, the reporting, review and approval will occur prior to entry into the transaction. If advance review and approval is not practicable, the audit committee will review and, in its discretion, may ratify the related-person transaction. The policy also permits the chair of the audit committee to review, and if deemed appropriate approve, proposed related-person transactions that arise between audit committee meetings, subject to ratification by the audit committee at its next meeting. Any related-person transactions that are ongoing in nature will be reviewed annually. A related-person transaction reviewed under the policy will be considered approved or ratified if it is authorized by the audit committee after full disclosure of the related person's interest in the transaction. As appropriate for the circumstances, the committee will review and consider: • the related person’s interest in the related-person transaction; • the approximate dollar amount involved in the related-person transaction; • the approximate dollar amount of the related person’s interest in the transaction without regard to the amount of any profit or loss; 126 • whether the transaction was undertaken in the ordinary course of our business; • whether the terms of the transaction are no less favorable to us than terms that could have been reached with an unrelated third party; • the purpose of, and the potential benefits to us of, the related-person transaction; and • any other information regarding the related-person transaction or the related person in the context of the proposed transaction that would be material to investors in light of the circumstances of the particular transaction. The audit committee may approve or ratify the transaction only if the audit committee determines that, under all of the circumstances, the transaction is not inconsistent with our best interests. The audit committee may impose any conditions on the related-person transaction that it deems appropriate. The policy provides that transactions involving compensation of executive officers will be reviewed and approved by the compensation committee of our Board of Directors in the manner specified in its charter. Director Independence Nasdaq rules require a majority of a listed company's board of directors to be comprised of independent directors. In addition, Nasdaq rules require that, subject to specified exceptions, each member of a listed company's audit, compensation and nominating and corporate governance committees be independent. Audit committee members must also satisfy independence criteria set forth in Rule 10A-3 under the Securities Exchange Act of 1934, as amended, or the Exchange Act, and compensation committee members must also satisfy the independence criteria set forth in Rule 10C-1 under the Exchange Act. The Nasdaq independence definition includes a series of objective tests, such as that the director is not, and has not been for at least three years, one of our employees and that neither the director nor any of his or her family members has engaged in various types of business dealings with us. In addition, under applicable Nasdaq rules, a director will only qualify as an "independent director" if, in the opinion of the listed company's board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries. In order to be considered independent for purposes of Rule 10C-1, the board must consider, for each member of a compensation committee of a listed company, all factors specifically relevant to determining whether a director has a relationship to such company which is material to that director's ability to be independent from management in connection with the duties of a compensation committee member, including, but not limited to: (1) the source of compensation of the director, including any consulting advisory or other compensatory fee paid by such company to the director; and (2) whether the director is affiliated with the company or any of its subsidiaries or affiliates. Our Board of Directors has determined that all members of the Board of Directors, except Alexander Cumbo and Ilan Ganot, are independent directors, as defined under applicable Nasdaq rules. In March 2024, our Board of Directors also previously determined that Adam Koppel and Rajeev Shah, former directors who resigned from our board of directors, effective June 11, 2024, were independent directors, as defined under applicable Nasdaq rules. In making such determinations, our Board of Directors considered the relationships that each director has with our Company and all other facts and circumstances that our Board of Directors deemed relevant in determining his or her independence, including the beneficial ownership of our common stock by each director. Mr. Cumbo is not an independent director under applicable rules because he is our President and Chief Executive Officer. Mr. Ganot is not an independent director under applicable rules because he was our President and Chief Executive Officer until December 2, 2022. Our Board of Directors has determined that the composition of our committees currently complies with all applicable independence requirements of Nasdaq and the rules and regulations of the SEC. Item 14. Principal Accountant Fees and Services. The following table represents aggregate fees billed to us by PricewaterhouseCoopers LLP, our independent registered public accounting firm, for the fiscal years ended December 31, 2024 and 2023: 127 Year Ended December 31, 2024 2023 Audit fees $ 752,500 $ 903,500 Audit-related fees — — Tax fees 67,160 66,463 All other fees 2,125 2,125 Total $ 821,785 $ 972,088 The services rendered by PricewaterhouseCoopers LLP in connection with the fees presented above were as follows: Audit Fees Audit fees consist of fees billed for professional services for the audit of our annual consolidated financial statements, the review of interim consolidated financial statements, and related services that are normally provided in connection with registration statements. Tax Fees Tax fees consist of fees for professional services related to tax compliance and consultations. All Other Fees All other fees include license fees for web-based accounting research tools. Pre-Approval Policies The audit committee has not adopted policies and procedures for the pre-approval of audit and non-audit services rendered by our independent registered public accounting firm and, consequently, all audit and non-audit services are pre-approved by the whole audit committee or the chair of the audit committee. All fees for the fiscal years ended December 31, 2024 and 2023 were so pre-approved. 128 PART IV Item 15. Exhibits and Financ ial Statement Schedules. (1) Financial Statements: Page Report of Independent Registered Public Accounting Firm (PCAOB ID 238 ) F- 1 Consolidated Balance Sheets at December 31, 2024 and 2023 F- 3 Consolidated Statements of Operations for the Years Ended December 31, 2024 and 2023 F- 4 Consolidated Statements of Comprehensive Loss for the Years Ended December 31, 2024 and 2023 F- 5 Consolidated Statements of Changes in Stockholders’ Equity for the Years Ended December 31, 2024 and 2023 F- 6 Consolidated Statements of Cash Flows for the Years Ended December 31, 2024 and 2023 F- 7 Notes to Consolidated Financial Statements F- 9 (2) Financial Statement Schedules: All financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the financial statements or the notes thereto. (3) Exhibits. The following is a list of exhibits filed as part of this Annual Report on Form 10-K. 129 Exhibit Number Description 2.1 Agreement and Plan of Merger, dated as of September 29, 2022, by and among Solid Biosciences Inc., Greenland Merger Sub LLC, AavantiBio, Inc. and, solely in his capacity as the Equityholder Representative, Doug Swirsky (incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K filed on September 30, 2022). 3.1 Certificate of Incorporation of Solid Biosciences Inc., as amended (incorporated herein by reference to Exhibit 4.1 to the Registrant's Registration Statement on Form S-8 (File No. 333-280116) on June 11, 2024) . 3.2 Bylaws of Solid Biosciences Inc. (incorporated by reference to Exhibit 4.2 to the Registration Statement on Form S-8 filed on January 29, 2018). 4.1 Specimen Common Stock Certificate (incorporated by reference to Exhibit 4.1 to the Registration Statement on Form S-1 filed on December 29, 2017). 4.2 Description of the Company’s Securities Registered under Section 12 of the Exchange Act (incorporated by reference to Exhibit 4.2 to the Annual Report on Form 10-K filed on March 23, 2023). 10.1† Amended and Restated Registration Rights Agreement dated March 29, 2017 by and among Solid Biosciences, LLC and certain investors (incorporated by reference to Exhibit 10.17 to the Registration Statement on Form S-1 filed on December 29, 2017). 10.2† Solid Biosciences, LLC Amended and Restated Equity Incentive Plan and form of unit restriction agreement (incorporated by reference to Exhibit 10.7 to the Annual Report on Form 10-K filed on March 29, 2018). 10.3† Solid Biosciences Inc. 2018 Omnibus Incentive Plan (incorporated by reference to Exhibit 99.1 to the Registration Statement on Form S-8 filed on January 29, 2018). 10.4† Form of Incentive Stock Option Agreement under 2018 Omnibus Incentive Plan (incorporated by reference to Exhibit 10.7 to the Annual Report on Form 10-K filed on March 13, 2019). 10.5† Form of Nonqualified Stock Option Agreement under 2018 Omnibus Incentive Plan (incorporated by reference to Exhibit 10.8 to the Annual Report on Form 10-K filed on March 13, 2019). 10.6† Form of Restricted Stock Agreement under 2018 Omnibus Incentive Plan (incorporated by reference to Exhibit 10.9 to the Registration Statement on Form S-1 filed on December 29, 2017). 10.7# Exclusive Patent License Agreement, dated as of October 16, 2015, by and between Solid GT, LLC and the University of Washington (incorporated by reference to Exhibit 10.7 to the Annual Report on Form 10-K filed on March 13, 2024). 10.8# License Agreement, dated as of October 15, 2015, by and between Solid GT, LLC and The Curators of the University of Missouri (incorporated by reference to Exhibit 10.8 to the Annual Report on Form 10-K filed on March 13, 2024). 10.9† Form of Indemnification Agreement for Directors and Officers (incorporated by reference to Exhibit 10.16 to the Registration Statement on Form S-1 filed on December 29, 2017). 10.10*† Summary of Non-Employee Director Compensation Program 10.11 Form of Pre-Funded Warrant to Purchase Common Stock (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed on July 26, 2019). 10.12 Registration Rights Agreement, dated July 25, 2019, by and among the Company and the other parties thereto (incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed on July 26, 2019) . 10.13† Consulting Agreement, dated as of November 19, 2020, by and between Solid Biosciences Inc. and Danforth Advisors, LLC (incorporated by reference to Exhibit 10.24 to the Annual Report on Form 10-K filed on March 15, 2021). 10.14*† Executive Chair Agreement, effective January 1, 2022, by and between Solid Biosciences Inc. and Ian F. Smith, as amended by the First Amendment to Executive Chair Agreement, effective September 30, 2022, Second Amendment to the Executive Chair Agreement, effective January 1, 2024, and Third Amendment to the Executive Chair Agreement, effective January 6, 2025. 130 10.15† Amended and Restated 2020 Equity Incentive Plan, as amended (incorporated herein by reference to Exhibit 99.1 to the Registrant's Registration Statement on Form S-8 (File No. 333-280116) filed on June 11, 2024). 10.16† Form of Stock Option Agreement under the 2020 Equity Incentive Plan (incorporated by reference to Exhibit 10.4 to the Quarterly Report on Form 10-Q filed on August 6, 2020). 10.17† Form of Restricted Stock Unit Agreement under the 2020 Equity Incentive Plan (incorporated by reference to Exhibit 10.28 to the Annual Report on Form 10-K filed on March 14, 2022). 10.18 Stock Purchase Agreement, dated as of October 22, 2020, by and between the Company and Ultragenyx Pharmaceutical Inc. (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q filed on November 5, 2020). 10.19# Investor Agreement, dated as of October 22, 2020, by and between the Company and Ultragenyx Pharmaceutical Inc. (incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q filed on November 5, 2020). 10.20# First Amendment, dated as of October 9, 2020, to the Exclusive Patent License by and between the Company and the University of Washington (incorporated by reference to Exhibit 10.4 to the Quarterly Report on Form 10-Q filed on November 5, 2020). 10.21 Registration Rights Agreement, dated December 10, 2020, by and among the Company and the other parties thereto (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed on December 11, 2020). 10.22# First Amendment, dated as of January 27, 2021, to the Exclusive Patent License by and between the Company and the Curators of the University of Missouri (incorporated by reference to Exhibit 10.36 to the Annual Report on Form 10-K filed on March 14, 2021). 10.23 Lease, dated June 15, 2021, between Solid Biosciences Inc. and Hood Park LLC (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q filed on August 16, 2021). 10.24† Amended and Restated 2021 Employee Stock Purchase Plan.(incorporated by reference to Exhibit 10.27 to the Annual Report on Form 10-K filed on March 13, 2024). 10.25† Form of Nonstatutory Inducement Stock Option Agreement (incorporated by reference to Exhibit 10.4 to the Quarterly Report on Form 10-Q filed on August 16, 2021). 10.26† Form of Inducement Restricted Stock Unit Award Agreement (incorporated by reference to Exhibit 99.5 to the Registration Statement on Form S-8 filed on August 16, 2021). 10.27 Amended and Restated Sales Agreement, dated March 13, 2024, by and between the Company and Jefferies LLC (incorporated by reference to Exhibit 10.30 to the Annual Report on Form 10-K filed on March 13, 2024). 10.28 Form of Parent Support Agreement (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed on September 30, 2022). 10.29 Form of Support and Joinder Agreement (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed on September 30, 2022). 10.30 Registration Rights Agreement, dated September 29, 2022, by and among Solid Biosciences Inc. and the persons party thereto (incorporated by reference to Exhibit 10.4 to the Current Report on Form 8-K filed on September 30, 2022). 10.31† Employment Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and Alexander Cumbo (incorporated by reference to Exhibit 10.5 to the Current Report on Form 8-K filed on September 30, 2022). 10.32† Executive Transition and Separation Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and Ilan Ganot (incorporated by reference to Exhibit 10.6 to the Current Report on Form 8-K filed on September 30, 2022). 10.33† Consulting Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and Ilan Ganot (incorporated by reference to Exhibit 10.7 to the Current Report on Form 8-K filed on September 30, 2022). 10.34† Executive Transition and Separation Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and Erin Powers Brennan (incorporated by reference to Exhibit 10.8 to the Current Report on Form 8-K filed on September 30, 2022). 131 10.35† Consulting Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and Erin Powers Brennan (incorporated by reference to Exhibit 10.9 to the Current Report on Form 8-K filed on September 30, 2022). 10.36 Employment Agreement, dated September 29, 2022, by and between Solid Biosciences Inc. and David Tyronne Howton (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q filed on May 11, 2023). 10.37 Employment Agreement, dated October 2, 2023, by and between Solid Biosciences Inc. and Gabriel Brooks (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q filed on November, 8 2023). 10.38# Standard Exclusive License Agreement With Know-How (Agreement No. A19110), dated as of March 17, 2020, by and between AavantiBio, Inc. and University of Florida Research Foundation, Incorporated, as amended on August 23, 2022 (incorporated by reference to Exhibit 10.42 to the Annual Report on Form 10-K filed as on March 23, 2023). 10.39# Standard Exclusive License Agreement With Know-How (Agreement No. A19111), dated as of March 17, 2020, by and between AavantiBio, Inc. and University of Florida Research Foundation, Incorporated, as amended on May 25, 2021 and August 23, 2022 (incorporated by reference to Exhibit 10.43 to the Annual Report on Form 10-K filed on March 23, 2023). 10.40 Form on Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to the Current Report on Form 8-K filed on January 8, 2024). 10.41 Form of Registration Rights Agreement, dated January 8, 2024, by and among Solid Biosciences Inc. and the other parties thereto (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed on January 8, 2024). 10.42† 2024 Inducement Stock Incentive Plan (incorporated by reference to Exhibit 10.49 to the Annual Report on Form 10-K filed on March 13, 2024). 10.43† Form of Non-Statutory Stock Option Agreement under the 2024 Inducement Stock Incentive Plan (incorporated by reference to Exhibit 10.50 to the Annual Report on Form 10-K filed on March 13, 2024) . 10.44† Form of Restricted Stock Unit Agreement under the 2024 Inducement Stock Incentive Plan. Form of Restricted Stock Unit Agreement under the 2024 Inducement Stock Incentive Plan (incorporated by reference to Exhibit 10.51 to the Annual Report on Form 10-K filed on March 13, 2024). 10.45† Form of Restricted Stock Unit Agreement under the 2020 Equity Incentive Plan (incorporated by reference to Exhibit 10.52 to the Annual Report on Form 10-K filed on March 13, 2024). 10.46## Patent License Agreement, dated as of March 10, 2016, by and between Solid GT, LLC and the Regents of the University of Michigan.(incorporated by reference to Exhibit 10.53 to the Annual Report on Form 10-K filed on March 13, 2024). 10.47## Life Technologies Cell Line License Agreement, dated as of November 20, 2016, by and between Solid Biosciences, LLC and Life Technologies Corporation (incorporated by reference to Exhibit 10.54 to the Annual Report on Form 10-K filed on March 13, 2024). 10.48## License Agreement, dated as of June 23, 2016, by and between Solid GT, LLC and President and Fellows of Harvard College (incorporated by reference to Exhibit 10.55 to the Annual Report on Form 10-K filed on March 13, 2024). 10.49## License Agreement, dated as of August 3, 2017, by and between Solid Biosciences, LLC and President and Fellows of Harvard College (incorporated by reference to Exhibit 10.56 to the Annual Report 10-K filed March 13, 2024). 10.50*# Research, Collaboration & License Agreement, dated as of November 4, 2020, by and between the Trustees of the University of Pennsylvania and FA212 LLC, as amended 10.51*# Asset Purchase Agreement, dated as of September 19, 2024, by and between Solid Biosciences Inc. and FA212 LLC 10.52 Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to the Current Report on Form 8-K filed on February 18, 2025) . 19.1* Insider Trading Policy. 21.1* Subsidiaries of Solid Biosciences Inc. 132 23.1* Consent of PricewaterhouseCoopers LLP, Independent Registered Public Accounting Firm. 31.1* Certification of Chief Executive Officer of the Registrant Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 31.2* Certification of Chief Financial Officer of the Registrant Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1** Certification of Chief Executive Officer of the Registrant Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 32.2** Certification of Chief Financial Officer of the Registrant Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 97.1 Dodd-Frank Compensation Recovery Policy (incorporated by reference to Exhibit 97.1 to the Annual Report on Form 10-K filed on March 13, 2024). 101.INS Inline XBRL Instance Document. 101.SCH Inline XBRL Taxonomy Extension Schema Document With Embedded Linkbase Documents 104 Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101). * Filed herewith. ** Furnished herewith. † Indicates management contract or compensatory plan. # Certain portions of this exhibit have been omitted because they are not material and contain information that the Registrant customarily and actually treats as private or confidential. ## Filed with this Annual Report on Form 10-K solely for the purpose of transitioning this previously-filed exhibit, which is the subject of expiring confidential treatment orders, to the rules governing the filing of redacted exhibits under Regulation S-K Item 601(b)(10)(iv) pursuant to the SEC’s CF Disclosure Guidance: Topic 7. Portions of this exhibit have been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K. Item 16. Form 10-K Summary. Not applicable. 133 SIGNAT URES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized . SOLID BIOSCIENCES INC. Date: March 6, 2025 By: /s/ Alexander Cumbo Alexander Cumbo President, Chief Executive Officer and Director (Principal Executive Officer) Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this Report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated. /s/ Alexander Cumbo Alexander Cumbo President, Chief Executive Officer and Director (Principal Executive Officer) March 6, 2025 /s/ Kevin Tan Kevin Tan Chief Financial Officer (Principal Financial and Accounting Officer) March 6, 2025 /s/ Ian F. Smith Ian F. Smith Executive Chairman of the Board March 6, 2025 /s/ Martin Freed Martin Freed Director March 6, 2025 /s/ Ilan Ganot Director March 6, 2025 Ilan Ganot /s/ Clare Kahn Director March 6, 2025 Clare Kahn /s/ Georgia Keresty Director March 6, 2025 Georgia Keresty /s/ Sukumar Nagendran Sukumar Nagendran Director March 6, 2025 /s/ Adam Stone Adam Stone Director March 6, 2025 /s/ Lynne Sullivan Lynne Sullivan Director March 6, 2025 134 Report of Independent Registered Public Accounting Firm To the Board of Directors and Stockholders of Solid Biosciences, Inc. Opinion on the Financial Statements We have audited the accompanying consolidated balance sheets of Solid Biosciences, Inc. and its subsidiaries (the “Company”) as of December 31, 2024 and 2023, and the related consolidated statements of operations, of comprehensive loss, of changes in stockholders’ equity and of cash flows for the years then ended, including the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for the years then ended in conformity with accounting principles generally accepted in the United States of America. Basis for Opinion These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements 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 of these consolidated financial statements 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. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion. Our audits 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. We believe that our audits provide a reasonable basis for our opinion. 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 relates to accounts or disclosures that are material to the consolidated financial 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. External Research and Development Costs As described in Note 2 to the consolidated financial statements, research and development costs are expensed as incurred. Research and development expenses include salaries, equity-based compensation and benefits of employees, third-party license fees and other operational costs related to the Company’s research and development activities, including allocated facility-related expenses and external costs of outside vendors engaged to conduct both preclinical studies and clinical trials. The Company has entered into various research and development contracts with research institutions and other companies. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. Management records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, management analyzes progress of the studies, including the phase or completion of events, invoices received and F- 1 contracted costs. As disclosed by management, the majority of service providers invoice the Company in arrears for services performed, on a pre-determined schedule or when contractual milestones are met; however, some require advanced payments. The Company’s research and development expense for the year ended December 31, 2024 was $96.4 million, a majority of which relates to external research and development costs. The principal consideration for our determination that performing procedures relating to external research and development costs is a critical audit matter is a high degree of auditor effort in performing procedures related to the Company’s external research and development costs. 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, among others, testing external research and development costs on a sample basis by agreeing relevant information, including overall contract value, amounts incurred to date, and percentage of completion amounts to the (i) underlying agreements with outside vendors engaged to conduct preclinical studies and clinical trials, (ii) purchase orders, (iii) invoices received, (iv) underlying payments made for expenses incurred on the contracts, and (v) external confirmations or communications obtained by management from outside vendors. /s/ PricewaterhouseCoopers LLP Boston, Massachusetts March 6, 2025 We have served as the Company's auditor since 2017. F- 2 SOLID BIOSCI ENCES INC. CONSOLIDATED B ALANCE SHEETS (In thousands, except share and per share data) December 31, 2024 2023 Assets Current assets: Cash and cash equivalents $ 80,235 $ 74,015 Available-for-sale securities 68,685 49,625 Prepaid expenses and other current assets 8,382 6,094 Total current assets 157,302 129,734 Non-current assets: Operating lease, right-of-use asset 24,295 26,539 Property and equipment, net 4,747 6,624 Other non-current assets 366 209 Restricted cash 1,952 1,833 Total non-current assets 31,360 35,205 Total assets $ 188,662 $ 164,939 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 4,237 $ 2,032 Accrued expenses and other current liabilities 19,852 10,161 Operating lease liabilities 1,787 1,855 Finance lease liabilities 1,231 469 Derivative liabilities 3,150 — Total current liabilities 30,257 14,517 Non-current liabilities: Operating lease liabilities, net of current portion 21,159 22,707 Finance lease obligations, net of current portion — 1,234 Total non-current liabilities 21,159 23,941 Total liabilities 51,416 38,458 Commitments and Contingencies (Note 11) Stockholders’ Equity: Preferred stock, $ 0.001 par value; 10,000,000 shares authorized at December 31, 2024 and 2023; no shares issued and outstanding at December 31, 2024 and 2023 — — Common stock, $ 0.001 par value; 120,000,000 and 60,000,000 shares authorized at December 31, 2024 and 2023, respectively; 40,468,141 and 20,386,606 shares issued and outstanding at December 31, 2024 and 2023, respectively 40 20 Additional paid-in capital 920,609 785,199 Accumulated other comprehensive income 47 15 Accumulated deficit ( 783,450 ) ( 658,753 ) Total stockholders' equity 137,246 126,481 Total liabilities and stockholders' equity $ 188,662 $ 164,939 The accompanying notes are an integral part of these consolidated financial statements. F- 3 SOLID BIOSCIENCES INC. CONSOLIDATED STATEME NTS OF OPERATIONS (In thousands, except share and per share data) Year Ended December 31, 2024 2023 Operating expenses: Research and development $ 96,431 $ 76,563 General and administrative 33,297 27,752 Restructuring expense — ( 63 ) Total operating expenses 129,728 104,252 Loss from operations ( 129,728 ) ( 104,252 ) Other income, net: Interest income 9,469 7,582 Interest expense ( 340 ) ( 440 ) Change in fair value of derivative liabilities ( 4,750 ) — Other income, net 652 1,095 Total other income, net 5,031 8,237 Net loss $ ( 124,697 ) $ ( 96,015 ) Net loss per share, basic and diluted $ ( 3.06 ) $ ( 4.83 ) Weighted average shares of common stock outstanding used to compute basic and diluted net loss per share 40,816,694 19,884,007 The accompanying notes are an integral part of these consolidated financial statements. F- 4 SOLID BIOSCIENCES INC. CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (In thousands) Year Ended December 31, 2024 2023 Net loss $ ( 124,697 ) $ ( 96,015 ) Other comprehensive income: Unrealized gain on available-for-sale securities 32 83 Comprehensive loss $ ( 124,665 ) $ ( 95,932 ) The accompanying notes are an integral part of these consolidated financial statements. F- 5 SOLID BIOSCIENCES INC. CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (In thousands, except share data) Common Stock Additional Paid Accumulated Other Comprehensive Accumulated Total Stockholders' Shares Amount in Capital Income (Loss) Deficit Equity Balance at January 1, 2023 19,556,732 $ 20 $ 774,452 $ ( 68 ) $ ( 562,738 ) $ 211,666 Issuance of common stock in public offering, net of sales commissions of $ 76 602,030 — 2,974 — — 2,974 Vesting of restricted stock units 183,951 — — — — — Issuance of common stock under employee stock purchase plan 43,893 — 148 — — 148 Unrealized gain on available-for-sale securities — — — 83 — 83 Equity-based compensation — — 7,625 — — 7,625 Net loss — — — — ( 96,015 ) ( 96,015 ) Balance at December 31, 2023 20,386,606 20 785,199 15 ( 658,753 ) 126,481 Issuance of common stock in private placement, net of issuance costs of $ 4,407 16,973,103 17 89,437 — — 89,454 Issuance of pre-funded warrants in private placement, net of issuance costs of $ 704 — — 14,293 — — 14,293 Issuance of common stock in public offering, net of sales commissions of $ 471 2,212,937 2 18,367 — — 18,369 Issuance of common stock in private placement for upfront consideration 364,990 — 2,000 — — 2,000 Vesting of restricted stock units 335,981 1 — — — 1 Issuance of common stock under employee stock purchase plan 122,962 — 337 — — 337 Exercise of common stock options 71,562 — 457 — — 457 Unrealized gain on available-for-sale securities — — — 32 — 32 Equity-based compensation — — 10,519 — — 10,519 Net loss — — — — ( 124,697 ) ( 124,697 ) Balance at December 31, 2024 40,468,141 $ 40 $ 920,609 $ 47 $ ( 783,450 ) $ 137,246 The accompanying notes are an integral part of these consolidated financial statements. F- 6 SOLID BIOSCIENCES INC. CONSOLIDATED STATEME NTS OF CASH FLOWS (In thousands) Year Ended December 31, 2024 2023 Operating activities: Net loss $ ( 124,697 ) $ ( 96,015 ) Adjustments to reconcile net loss to net cash used in operating activities: Net amortization of discount on available-for-sale securities ( 3,592 ) ( 2,408 ) Equity-based compensation expense 10,519 7,625 Depreciation and amortization expense 2,455 2,581 Non-cash lease expense 2,391 2,531 Non-cash acquired in-process research and development 3,400 — Common stock issued as up-front payment for collaboration and license agreement 2,000 — Change in fair value of derivative liabilities 4,750 — Other ( 88 ) 374 Changes in operating assets and liabilities: Prepaid expenses and other current and non-current assets ( 2,445 ) 598 Accounts payable 2,205 ( 764 ) Change in operating lease liability ( 1,676 ) ( 1,735 ) Accrued expenses and other current and non-current liabilities 4,766 ( 6,967 ) Net cash used in operating activities ( 100,012 ) ( 94,180 ) Investing activities: Purchases of property and equipment ( 654 ) ( 1,515 ) Proceeds from sale of property and equipment 5 — Proceeds from sales and maturities of available-for-sale securities 188,900 128,632 Purchases of available-for-sale securities ( 204,337 ) ( 117,428 ) Net cash (used in) provided by investing activities ( 16,086 ) 9,689 Financing activities: Proceeds from issuance of common stock and pre-funded warrants in private placement 108,858 — Payments of common stock and pre-funded warrants issuance costs in private placement ( 5,111 ) — Proceeds from issuance of common stock in public offering, net of sales commissions 18,369 2,974 Proceeds from exercise of stock options 457 — Employee stock purchase plan purchases 337 148 Payments of principal portion of finance lease obligations ( 473 ) Net cash provided by financing activities 122,437 3,122 Net increase (decrease) in cash, cash equivalents and restricted cash 6,339 ( 81,369 ) Cash, cash equivalents, and restricted cash at beginning of period 75,848 157,217 Cash, cash equivalents, and restricted cash at end of period $ 82,187 $ 75,848 Year Ended December 31, 2024 2023 Supplemental disclosure of cash flow information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 4,264 $ 4,501 Operating cash flows for finance leases $ 469 $ 375 Financing cash flows for finance leases, cash paid for interest $ 340 $ 435 Supplemental disclosure of non-cash investing and financing activities: Right-of-use assets obtained in exchange for operating lease liabilities $ 407 $ 121 Decrease in right-of-use asset and lease liability due to lease termination $ ( 261 ) $ ( 252 ) Decrease in property, plant and equipment due to asset exchange $ — $ ( 950 ) Property and equipment purchases included in accounts payable and accruals $ — $ 76 The accompanying notes are an integral part of these consolidated financial statements. F- 7 SOLID BIOSCIENCES INC. CONSOLIDATED STATEMENTS OF CASH FLOWS (continued) (In thousands) The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the consolidated balance sheets to the amounts reported in the consolidated statements of cash flows: December 31, 2024 2023 Cash and cash equivalents $ 80,235 $ 74,015 Restricted cash, non-current 1,952 1,833 Total cash and cash equivalents, and restricted cash, as reported in the consolidated statements of cash flows $ 82,187 $ 75,848 The accompanying notes are an integral part of these consolidated financial statements. F- 8 SOLID BIOSCIENCES INC. NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Amounts in thousands, except share and per share data and where otherwise noted) 1. Nature of the Business and Basis of Presentation Nature of Business Solid Biosciences Inc. was organized in March 2013 under the name SOLID Ventures Management, LLC and operated as a Delaware limited liability company until immediately prior to the effectiveness of its registration statement on Form S-1 on January 25, 2018, at which time it completed a statutory corporate conversion into a Delaware corporation and changed its name to Solid Biosciences Inc. (the “Company”). On December 2, 2022, the Company completed its acquisition of AavantiBio, Inc. (“AavantiBio”), a privately held gene therapy company focused on transforming the lives of patients with Friedreich’s ataxia (“FA”) and rare cardiomyopathies (the “Acquisition”). Upon the consummation of the Acquisition, the Company acquired AavantiBio’s gene therapy programs, AVB‑202‑TT for FA and AVB‑401 for BAG3 mediated dilated cardiomyopathy, as well as additional assets for the treatment of other cardiac diseases, platform technologies and know-how related thereto. AavantiBio is a wholly owned subsidiary of the Company. The Company is a life sciences company focused on advancing a portfolio of current and future gene therapy candidates (collectively, “Candidates”), including SGT-003 for the treatment of Duchenne muscular dystrophy (“Duchenne”), SGT-212 for the treatment of FA, SGT-501 for the treatment of catecholaminergic polymorphic ventricular tachycardia, SGT-601 for the treatment of TNNT2-mediated dilated cardiomyopathy, and additional assets for the treatment of genetic cardiac and other diseases, at different stages of development with varying levels of investment. The Company is advancing its diverse pipeline across rare neuromuscular and cardiac diseases, bringing together experts in science, technology, disease management and care. Patient-focused and founded by those directly impacted by Duchenne, the Company’s mission is to improve the daily lives of patients living with these devastating diseases. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on licenses, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies and clinical trials and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting capabilities. The Company’s Candidates are in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from, among others, other pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, partners, and consultants. Liquidity The accompanying consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Through December 31, 2024, the Company has funded its operations primarily with the proceeds from the sale of redeemable preferred units and member units as well as the sale of common stock and pre-funded warrants to purchase shares of its common stock in private placements and the sale of common stock in its initial public offering and follow-on public offering in March 2021 and under its at-the-market sales agreement. On January 11, 2024, the Company issued and sold in a private placement 16,973,103 shares of the Company’s common stock at a price per share of $ 5.53 and, to one investor in lieu of shares of common stock, pre-funded warrants to purchase 2,712,478 shares of common stock at a price of $ 5.529 per pre-funded warrant (the “January 2024 Private Placement”). The Company received $ 103.7 million of net proceeds from the January 2024 Private Placement after deducting offering costs. No warrants were exercised during the year ended December 31, 2024. F- 9 During the year ended December 31, 2024, the Company issued 2,212,937 shares of its common stock, pursuant to the Company's “at-the-market offering” sales agreement, between the Company and Jefferies LLC (the “ATM Sales Agreement”) for net proceeds of $ 18.4 million. On February 19, 2025, the Company issued and sold 35,739,810 shares of its common stock at a price per share of $ 4.03 and, to certain investors in lieu of shares of common stock, pre-funded warrants to purchase 13,888,340 shares of common stock at a price of $ 4.029 per pre-funded warrant (the “February 2025 Offering"). The Company received approximately $ 187.5 million of net proceeds from the February 2025 Offering after deducting underwriting discounts and commissions and estimated offering costs. In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern , the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued. As of December 31, 2024, the Company had an accumulated deficit of $ 783.5 million. During the years ended December 31, 2024 and 2023, the Company incurred net losses of $ 124.7 million and $ 96.0 million, respectively. The Company used $ 100.0 million of cash in operations for the year ended December 31, 2024. The Company expects to continue to generate operating losses in the foreseeable future. Based upon its current operating plan, the Company expects that its cash, cash equivalents and available-for-sale securities of $ 148.9 million, excluding restricted cash of $ 2.0 million, as of December 31, 2024, together with the net proceeds from the February 2025 Offering, will be sufficient to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these financial statements. However, the Company has based this estimate on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects. The Company expects to finance its future cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements. If the Company is unable to obtain funding, the Company would be forced to delay, reduce or eliminate some or all of its research and development programs, preclinical and clinical testing or commercialization efforts, which could adversely affect its business prospects. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying consolidated financial statements include the accounts of the Company and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. Reclassifications Certain prior period amounts within cash flows from operating activities in the consolidated statement of cash flows have been reclassified to conform to the current period presentation. These reclassifications are not material and had no effect on the previously reported net cash used in operating activities. 2. Summary of Significant Accounting Policies Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, estimates related to recognition of research and development expenses, equity-based compensation and derivative liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from the Company’s estimates. Cash Equivalents The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents. Available-for-Sale Securities Available-for-sale securities consist of investments with original maturities greater than 90 days at acquisition date. The Company has classified its investments with maturities beyond one year as short term, based on their highly liquid nature and F- 10 because such available-for-sale securities represent the investment of cash that is available for current operations. The Company classifies all of its investments as available-for-sale securities. The Company’s investments are measured and reported at fair value using quoted prices in active markets for similar securities. Unrealized gains and losses on available-for-sale debt securities are reported as a separate component of stockholders’ equity. The cost of debt securities sold is determined on a specific identification basis, and realized gains and losses are included in other income, net within the consolidated statement of operations. Impairment of available-for-sale securities is evaluated considering numerous factors, and their relative significance varies depending on the situation. Factors considered include whether a decline in fair value below the amortized cost basis is due to credit-related factors or non-credit-related factors, the financial condition and near-term prospects of the issuer, and our intent and ability to hold the investment to allow for an anticipated recovery in fair value. A credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings. Any impairment that is not credit-related is recognized in other comprehensive income. No such adjustments were necessary during the periods presented. Concentration of Credit Risk and of Significant Suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and available-for-sale securities. Periodically, the Company maintains deposits in accredited financial institutions in excess of federally insured limits. The Company maintains each of its cash, cash equivalents and available-for-sale securities balances with high-quality and accredited financial institutions and accordingly, such funds are not exposed to significant credit risk. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on third-party manufacturers to supply products for research and development activities of its programs, including clinical and preclinical testing. These programs could be adversely affected by a significant interruption in the supply of such drug substance products. Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and available-for-sale securities are carried at fair value, determined according to the fair value hierarchy described above. Derivative liabilities are recorded at fair value based on the probability weighted present value of the estimated cash flows pursuant to the contractual terms of each agreement. The derivative liabilities are remeasured quarterly with changes in fair value recorded in change in fair value of derivative liabilities in the consolidated statements of operations. See Note 4, Fair Value of Financial Assets and Liabilities , for additional information. The carrying values of the Company’s accounts payable and accrued expenses and other current liabilities approximate their fair value due to the short-term nature of these liabilities. Leases At the inception of a contract, the Company determines if a contract meets the definition of a lease. A lease is a contract, or part of a contract, that conveys the right to control the use of identified property, plant, or equipment (an identified asset) for a period of time in exchange for consideration. The Company determines if the contract conveys the right to control the use of an identified asset for a period of time. The Company assesses throughout the period of use whether the Company has both of the following: (1) the right to obtain substantially all of the economic benefits from use of the identified asset and (2) the F- 11 right to direct the use of the identified asset. This determination is reassessed if the terms of the contract are changed. Leases are classified as operating or finance leases based on the terms of the lease agreement and certain characteristics of the identified asset. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of the minimum future lease payments. Adjustments to the right-of-use asset may be required for items such as lease prepayments or incentives received. The Company’s policy is to not record leases with an original term of twelve months or less on the consolidated balance sheets. The Company recognizes lease expense for these short-term leases on a straight-line basis over the lease term. Certain lease agreements include rental payments that are adjusted periodically for inflation or other variables. In addition to rent, the leases may require the Company to pay additional amounts for taxes, insurance, maintenance and other expenses, which are generally referred to as non-lease components. Such adjustments to rental payments and variable non-lease components are treated as variable lease payments and recognized in the period in which the obligation for these payments was incurred. Variable lease components and variable non-lease components are not measured as part of the right-of-use asset and liability. Only when lease components and their associated non-lease components are fixed are they accounted for as a single lease component and recognized as part of a right-of-use asset and liability. Total contract consideration is allocated to the combined fixed lease and non-lease components. Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the useful life of the asset. Laboratory equipment is depreciated over five years . Computer equipment is depreciated over three years . Computer software is depreciated over two years . Furniture and office equipment are depreciated over five years . Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the related asset . Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the net book value is written off and any resulting gain or loss is included in the consolidated statements of operations. Equipment under a finance lease is stated at fair value at the inception of the lease less accumulated depreciation and is depreciated over the remaining lease term or the estimated useful life of the equipment. Impairment of Long-Lived Assets Long-lived assets, comprised of property and equipment, to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. Exclusive Licenses If a license granted in an arrangement is determined to be distinct from the other promises or performance obligations identified in the arrangement, which generally include research and development services, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license In assessing whether a license is distinct from the other promises, the Company considers relevant facts and circumstances of each arrangement, including the research and development capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. In addition, the Company considers whether the collaboration partner can benefit from the license for its intended purpose without the receipt of the remaining promise, whether the value of the license is dependent on the unsatisfied promise, whether there are other vendors that could provide the remaining promise, and whether it is separately identifiable from the remaining promise. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The measure of progress, and thereby periods over which revenue should be recognized, are subject to estimates by management and may change over the course of the arrangement. F- 12 Research and Development Services The promises under the Company’s collaboration and license agreements generally include research and development services to be performed by the Company on behalf of the collaboration partner. For performance obligations that include research and development services, the Company generally recognizes revenue allocated to such performance obligations based on an appropriate measure of progress. The Company utilizes judgment to determine the appropriate method of measuring progress for purposes of recognizing revenue, which is generally an input measure, such as costs incurred. Milestone Payments At the inception of each arrangement that includes milestone payments based on certain events, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant reversal in the amount of cumulative revenue recognized would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company, such as regulatory approvals, are not considered probable of being achieved until those approvals are received or the specified event occurs. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. There is considerable judgment involved in determining whether it is probable that a significant reversal in the amount of cumulative revenue recognized would not occur. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. If a milestone or other variable consideration relates specifically to the Company’s efforts to satisfy a single performance obligation or to a specific outcome from satisfying the performance obligation, the Company generally allocates the milestone amount entirely to that performance obligation once it is probable that a significant reversal in the amount of cumulative revenue recognized would not occur. Royalties For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its licensing arrangements. Collaboration Revenue The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements (“ASC 808”) to determine whether such arrangements 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 assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and those that are more reflective of a vendor-customer relationship and therefore within the scope of ASC 606, Revenue from Contracts with Customers (“ASC 606”). For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, generally by analogy to ASC 606. Costs Associated with License and Collaborative Arrangements All costs associated with license and collaborative arrangements are expensed as incurred and recorded in research and development expense in the consolidated statements of operations. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include salaries, equity-based compensation and benefits of employees, third-party license fees and other operational costs related to the Company’s research and development activities, including allocated facility-related expenses and external costs of outside vendors engaged to conduct both preclinical studies and clinical trials. Non-refundable pre-payments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are recognized as F- 13 expense as the goods or services are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered or the services rendered. The Company may in-license the rights to develop and commercialize product candidates. For each in-license transaction the Company evaluates whether it has acquired processes or activities along with inputs that would be sufficient to constitute a “business” as defined under GAAP. A “business” as defined under GAAP consists of inputs and processes applied to those inputs that have the ability to create outputs. Although businesses usually have outputs, outputs are not required for an integrated set of activities to qualify as a business. When the Company determines that it has not acquired sufficient processes or activities to constitute a business, any upfront payments, as well as milestone payments, are immediately expensed as acquired research and development in the period in which they are incurred. Research Contract Costs and Accruals The Company has entered into various research and development contracts with research institutions and other companies. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Estimates based on available information are made in determining the accrual balances at the end of any reporting period. Actual results could differ from the Company's estimates; however, the Company's historical accrual estimates have not been materially different from the actual costs. Patent Costs All patent-related costs incurred for filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. Equity-Based Compensation The Company measures all stock options and other stock-based awards granted to employees, directors and non-employees based on the fair value on the date of the grant and recognizes compensation expense of those awards, over the requisite service period, which is generally the vesting period of the respective award. Forfeitures are accounted for as they occur. The Company applies the straight-line method of expense recognition to all awards with only service-based vesting conditions. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. In the first quarter of 2024, the Company determined that it has adequate historical stock price data to utilize solely its own stock for historical volatility purposes. T he expected term of stock options with service-based vesting conditions and options granted to non-employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company utilized a 0 % expected dividend yield in its determination of grant fair value based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future, if ever. The fair values of restricted stock units and performance-based restricted stock units are measured at the grant date based on the closing price of the Company’s common stock on the date of grant. For restricted stock units, the fair value of the award is recognized on a straight-line basis over the requisite service periods. For performance-based restricted stock unit awards, which are subject to the achievement of performance milestones, the fair value is recognized as expense over the requisite service periods when the achievement of such performance milestones is determined to be probable. If a performance milestone is not determined to be probable or is not met, no equity-based compensation expense is recognized, and any previously recognized expense is reversed. Forfeitures are recognized as a reduction of equity-based compensation expense as they occur. The Company classifies stock-based compensation expense in its consolidated statements of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. The Company does not currently hold any treasury shares. Upon the exercise of stock options and the vesting of restricted stock units and performance stock units, the Company issues new shares of common stock and delivers them to the participant. Income Taxes Income taxes are accounted for under the asset and liability method. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are F- 14 expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The Company records valuation allowances to reduce deferred income tax assets to the amount that is more likely than not to be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, no amount of benefit attributable to the position is recognized. The tax benefit to be recognized of any tax position that meets the more likely than not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. Prior to January 25, 2018, the Company had not been subject to U.S. federal income taxes as the Company was organized as a limited liability company. As such, the taxable income or loss was passed through to and included in the tax returns of the members. Since January 25, 2018, the Company’s income has since been subject to U.S. federal, state, local, and foreign income taxes and taxed at the prevailing corporate tax rates. Segment Data The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on developing treatments through gene therapy and other means for patients with neuromuscular and cardiac diseases. All of the Company’s tangible assets are held in the United States. Please refer to Note 17, Segment Reporting for further information . Comprehensive Loss Comprehensive loss includes net loss, as well as other changes in stockholders’ equity that result from transactions and economic events other than those with members. The Company’s only element of other comprehensive income in all periods presented was unrealized gains from available-for-sale securities. Net Loss per Share The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and pre-funded warrants outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock and pre-funded warrants outstanding for the period, including potential dilutive shares of common stock assuming the dilutive effect of common stock equivalents. Any preferred stock that the Company may issue in the future could entitle the holders of such shares to participate in dividends and not require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss, diluted net loss per share is the same as basic net loss per share, since dilutive shares of common stock are not assumed to have been issued if their effect is anti-dilutive. As of December 31, 2024 and 2023, there was no preferred stock issued or outstanding with any contractual rights. Contingencies Loss contingency provisions are recorded if the potential loss from any claim, asserted or unasserted, or legal proceeding, is considered probable and the amount can be reasonably estimated, or a range of loss can be determined. These accruals represent the Company’s best estimate of probable loss. Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. The Company reviews the status of each significant matter and assesses its potential financial exposure. Significant judgment is required in both the determination of probability and the determination as to whether an exposure is reasonably estimable. Because of uncertainties related to these matters, accruals are based only on the best information available at the time. As additional information becomes available, the Company reassesses the potential liability related to pending claims and may change its estimates. These changes in the estimates of the potential liabilities could have a material impact on the Company’s consolidated results of operations and financial position. F- 15 Business Combinations The Company's consolidated financial statements include the operations of acquired businesses after the completion of the acquisitions. The Company accounts for acquired businesses using the acquisition method of accounting. Application of this method of accounting requires that (i) identifiable assets acquired (including identifiable intangible assets) and liabilities assumed be measured and recognized at fair value as of the acquisition date, and (ii) the excess of the purchase price over the net fair value of identifiable assets acquired and liabilities assumed be recorded as goodwill. Acquired in-process research and development (“IPR&D”) is recognized at fair value and initially characterized as an indefinite-lived intangible asset, irrespective of whether the acquired IPR&D has an alternative future use. Transaction costs are expensed as incurred. Amounts assigned to goodwill and other identifiable intangible assets are based on independent appraisals or internal estimates. Asset Acquisitions Acquisitions of assets or a group of assets that do not meet the definition of a business are accounted for as asset acquisitions using the cost accumulation method, whereby the cost of the acquisition, including certain transaction costs, is allocated to the assets acquired on the basis of relative fair values. No goodwill is recognized in an asset acquisition. Intangible assets that are acquired in an asset acquisition for use in research and development activities which have an alternative future use are capitalized as IPR&D. Acquired IPR&D which has no alternative future use is recognized as research and development expense at acquisition. Contingent milestone payments associated with asset acquisitions are recognized when probable and estimable. These amounts are expensed to research and development if there is no alternative future use associated with the asset or capitalized as an intangible asset if an alternative future use of the asset exists. Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. In November 2024, the FASB issued ASU No. 2024-03, "Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Sub-Topic 220-40) : Disaggregation of Income Statement Expenses," which requires additional disclosure of the nature of expenses included in the income statement. The standard requires disclosures about specific types of expenses included in the expense captions presented in the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted. The requirements should be applied on a prospective basis while retrospective application is permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. Recently Adopted Accounting Pronouncements On November 27, 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures ." Among other new disclosure requirements, ASU 2023-07 requires companies to disclose significant segment expenses that are regularly provided to the chief operating decision maker. We adopted the standard effective December 31, 2024 and applied the disclosure requirements retrospectively to all prior periods presented in the financial statements. Adoption of ASU 2023-07 did not have an impact on the Company’s consolidated financial position, results of operations, or cash flows. 3. FA212 Asset Acquisition On September 19, 2024 , the Company entered into an asset purchase agreement with FA212 LLC ("FA212") for the purchase of certain intellectual property, including patents and assigned licenses related to a pre-clinical drug candidate, which the Company now refers to as SGT-212, assigned manufacturing contracts as well as research and development materials such as manufactured materials and samples. The Company paid FA212 an upfront payment of $ 1.0 million. Additionally, the Company agreed to pay FA212 development milestone payments of up to $ 34.0 million, cumulative sales milestone payments of up to $ 21.0 million, and F- 16 tiered royalties on net sales in the low-single-digits. The Company also assumed from FA212 contingent development milestone payments of up to $ 4.2 million, regulatory milestone payments of up to $ 13.0 million, cumulative sales milestone payments of up to $ 27.5 million, and tiered royalties on worldwide net sales in the mid-single digits payable to the University of Pennsylvania. Certain development milestone payments to FA212 are payable in either cash, equity, or a combination of both, at the Company's discretion. Such contingent payments were determined to be derivative liabilities and were initially recorded at their fair value of $ 3.4 million, see Note 4, Fair Value of Financial Assets and Liabilities . The Company determined that th e FA212 agreement represented an asset acquisition of IPR&D assets with no alternative future use and recognized the aggregate acquisition cost of $ 5.1 million as research and development expense in the consolidated statement of operations for the year ended December 31, 2024, which included the upfront payment, initial recognition of the derivative liability and $ 0.7 million in transaction costs. The Company submitted an investigational new drug application ("IND") for SGT-212 for the treatment of FA to the U.S. Food and Drug Administration ("FDA"), which was cleared in December 2024. Upon clearance of the IND, a $ 5.0 million development milestone became payable to FA212. The $ 5.0 million milestone liability payment is included in Accrued expenses and other current liabilities in the accompanying consolidated balance sheet as of December 31, 2024. The derivative liabilities for the remaining contingent payments were recorded at a fair value of $ 3.2 million as of December 31, 2024. 4. Fair Value of Financial Assets and Liabilities The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis: December 31, 2024 Level 1 Level 2 Level 3 Total Financial assets Cash equivalents: Money market funds $ — $ 18,088 $ — $ 18,088 Treasury bills — 17,434 — 17,434 Total cash equivalents — 35,522 — 35,522 Available-for-sale securities (Note 5): Treasury bills — 27,895 — 27,895 Government bonds — 40,790 — 40,790 Total available-for-sale securities — 68,685 — 68,685 Total financial assets $ — $ 104,207 $ — $ 104,207 Financial liabilities Derivative liabilities $ — $ — $ 3,150 $ 3,150 Total financial liabilities $ — $ — $ 3,150 $ 3,150 December 31, 2023 Level 1 Level 2 Level 3 Total Financial assets Cash equivalents: Money market funds $ — $ 62,141 $ — $ 62,141 Certificates of deposit — 257 — 257 Total cash equivalents — 62,398 — 62,398 Available-for-sale securities (Note 5): Treasury bills — 49,625 — 49,625 Total available-for-sale securities — 49,625 — 49,625 Total financial assets $ — $ 112,023 $ — $ 112,023 As of December 31, 2024 and 2023, the fair values of the Company’s cash equivalents and available-for-sale securities were determined using Level 2 inputs. F- 17 The Company’s accounts payable, accrued expenses, and other current liabilities approximated their estimated fair values due to the short-term nature of these financial instruments. The Company estimated the fair value of the derivative liabilities by using a Monte Carlo simulation forecasting the timing and likelihood of certain development milestone events being achieved and discounting the probability adjusted payments using an appropriate discount rate based on market interest rates. The main assumptions when determining the fair value of the derivative liabilities are the timing of and probability of achieving certain milestones, the estimated volatility of the Company’s common stock, and the discount rate. The estimated fair value presented is not necessarily indicative of an amount that could be realized in a current market exchange. The use of alternative inputs and estimation methodologies could have a material effect on these estimates of fair value. Significant unobservable inputs for the derivative liabilities as of December 31, 2024 are as follows: Derivative Liabilities Valuation Technique Unobservable Input Range Average Development Milestones Monte Carlo Simulation Probability of achieving certain development milestones 28.0 % - 70.0 % 49.0 % Volatility 85.0 % 85.0 % Discount Rate 4.2 % - 4.3 % 4.3 % Timing of achieving certain development milestones 1.0 - 3.7 years 2.3 years Significant unobservable inputs for the derivative liabilities as of September 19, 2024 (the date of entry into the agreement with FA212) are as follows: Derivative Liabilities Valuation Technique Unobservable Input Range Average Development Milestones Monte Carlo Simulation Probability of achieving certain development milestones 2.0 % - 80.0 % 28.6 % Volatility 114.0 % 114.0 % Discount Rate 3.5 % - 4.8 % 3.8 % Timing of achieving certain development milestones 0.3 to 5.5 years 2.4 years The following table reflects the fair value of the Company's Level 3 derivative liabilities for the year ended December 31, 2024: Fair value of derivative liabilities as of December 31, 2023 $ — Fair value of derivative liabilities as of September 19, 2024 3,400 Change in fair value of derivative liabilities 4,750 Reclassification of accrued milestone payment to accrued expenses and other current liabilities ( 5,000 ) Fair value of derivative liabilities as of December 31, 2024 $ 3,150 During the years ended December 31, 2024 and 2023, there were no transfers between Level 1, Level 2 and Level 3. 5. Available-for-Sale Securities A summary of the Company’s available-for-sale securities is presented below: December 31, 2024 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Treasury bills maturing in one year or less $ 27,879 $ 16 $ — $ 27,895 Government bonds maturing in one year or less 40,759 31 — $ 40,790 Total available-for-sale securities $ 68,638 $ 47 $ — $ 68,685 F- 18 December 31, 2023 Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Treasury bills maturing in one year or less $ 49,610 $ 15 $ — $ 49,625 Total available-for-sale securities $ 49,610 $ 15 $ — $ 49,625 The weighted average contractual maturity of the Company’s available-for-sale securities was approximately 0.5 years and 0.4 years as of December 31, 2024 and 2023 , respectively. 6. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following: December 31, 2024 2023 Prepaid research and development expenses $ 6,731 $ 3,980 Prepaid other and other current assets 1,651 2,114 Total $ 8,382 $ 6,094 7. Property and Equipment Property and equipment consisted of the following: December 31, 2024 2023 Furniture and fixtures $ 936 $ 936 Laboratory equipment 14,404 16,137 Leasehold improvements 470 481 Computer equipment 764 842 Computer software 320 553 Construction in process 879 410 17,773 19,359 Less accumulated depreciation ( 13,026 ) ( 12,735 ) Total $ 4,747 $ 6,624 Depreciation and amortization expense w as $ 2.5 million and $ 2.6 million for the years ended December 31, 2024 and 2023 , respectively. The Company recognized an impairment loss $ 0.4 million for the year ended December 31, 2023. No impairment loss was recognized during the year ended December 31, 2024. 8. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: December 31, 2024 2023 Accrued research and development expense $ 7,268 $ 2,614 Accrued compensation 6,221 5,948 Accrued milestone payment (Note 3) 5,000 — Accrued other and other current liabilities 1,363 1,599 Total $ 19,852 $ 10,161 F- 19 9. Equity-Based Compensation Equity-Based Compensation Expense The Company has classified equity-based compensation in its consolidated statements of operations as follows: Year Ended December 31, 2024 2023 Research and development expenses $ 3,537 $ 3,094 General and administrative expenses 6,982 4,531 Total $ 10,519 $ 7,625 Equity Incentive Plans As of December 31, 2024, the Company’s approved equity incentive plans include: the 2018 Omnibus Incentive Plan (the “2018 Plan”); Amended and Restated 2020 Equity Incentive Plan (the “2020 Plan”); the Amended and Restated 2021 Employee Stock Purchase Plan (the "ESPP"); and the 2024 Inducement Stock Incentive Plan (the "2024 Inducement Plan"). These plans are administered by the Board of Directors (the "Board") and permit the granting of stock options, stock appreciation rights, restricted stock, restricted stock units ("RSUs"), performance awards, and/or other stock‑based or cash-based awards. Upon the adoption of the 2020 Plan, the Company no longer grants new equity awards under its 2018 Plan. Amended and Restated 2020 Equity Incentive Plan On June 11, 2024, the Company's stockholders approved an amendment to the 2020 Plan to increase the number of shares of common stock reserved for issuance under the plan by 2,000,000 shares. As of December 31, 2024, there were 2,000,796 stock options outstanding, 981,849 RSUs outstanding, 2,165,325 performance stock units outstanding, and 185,519 shares remained available for future issuance under the 2020 Plan. Amended and Restated 2021 Employee Stock Purchase Plan The ESPP was adopted by the Company's Board of Directors on April 14, 2021, approved by the stockholders on June 16, 2021, and became effective on June 16, 2021. The first offering period under the ESPP commenced on September 1, 2021. On June 6, 2023, the Company's stockholders approved an amendment and restatement of the ESPP to (i) increase the number of shares of common stock reserved for issuance under the ESPP from 73,525 to 473,525 and (ii) provide for an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2024 and ending with the fiscal year ending December 31, 2033, equal to the least of (a) 293,597 shares of common stock, (b) one percent ( 1 %) of the outstanding shares of common stock on such date and (c) the number of shares of common stock determined by the Board of Directors. The Company's Board of Directors amended and restated the ESPP on November 12, 2023 to provide for 24-month offering periods. The number of shares of the Company’s common stock reserved for issuance under the ESPP is 677,391 shares. At December 31, 2024 , 478,450 shares remained available for future issuance under the ESPP. 2024 Inducement Stock Incentive Plan In March 2024, the Board approved the 2024 Inducement Plan, which provides for the reservation of 1,000,000 shares of common stock for equity granted as an inducement material to the individual’s entering into employment with the Company and in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). As of December 31, 2024, there were 100,000 stock options outstanding, 300,067 RSUs outstanding, and 599,933 shares remained available for future issuance under the 2024 Inducement Plan. F- 20 Stock Options The table below summarizes the activity with respect to stock options for the year ended December 31, 2024: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at January 1, 2024 2,259,672 $ 21.93 $ 863 Granted 1,219,522 7.81 Exercised ( 71,562 ) 6.39 Expired ( 44,521 ) 31.11 Forfeitures ( 435,174 ) 8.93 Outstanding at December 31, 2024 2,927,937 $ 18.22 8.01 $ 193 Vested and expected to vest as of December 31, 2024 2,927,937 $ 18.22 8.01 $ 193 Exercisable at December 31, 2024 1,117,768 $ 35.27 6.79 $ 541 The assumptions used in the Black-Scholes option-pricing model for all stock options granted during each period presented are as follows: Year Ended December 31, 2024 2023 Common stock price $ 5.76 -$ 8.64 $ 2.15 -$ 7.33 Expected volatility 119.7 % - 128.7 % 121.8 % - 129.60 % Expected dividends 0.0 % 0.0 % Expected term (in years) 5.31 - 6.25 5.31 - 6.25 Risk-free rate 3.7 % - 4.4 % 3.5 % - 4.9 % The weighted average grant date fair values of stock options granted during the years ended December 31, 2024 and 2023 we re $ 6.96 and $ 4.76 , respectively. The Company recognize d $ 5.1 million and $ 5.3 million of equity-based compensation expense in connection with stock options during the years ended December 31, 2024 and 2023, respectively. As of December 31, 2024, there was $ 9.0 million of total unrecognized equity-based compensation cost related to unvested stock options. This cost is expected to be recognized over a weighted average period of 2 . 3 years. The intrinsic value of stock options exercised during the years ended December 31, 2024 and 2023 was $ 0.3 million and $ 0 , respectively. Restricted Stock Units The following table summarizes activity with respect to RSUs during the year ended December 31, 2024 : Units Weighted- Average Grant Date Fair Value Nonvested RSUs at January 1, 2024 877,181 $ 6.37 Granted 1,196,954 $ 7.94 Vested ( 335,981 ) $ 6.55 Forfeitures ( 257,882 ) $ 6.91 Nonvested RSUs at December 31, 2024 1,480,272 $ 7.50 The Company recognized $ 3.0 million and $ 2.2 million of equity-based compensation expense in connection with RSUs during the years ended December 31, 2024 and 2023, respectively. As of December 31, 2024, there was $ 9.0 million of total unrecognized equity-based compensation cost related to nonvested RSUs. This cost is expected to be recognized over a weighted average period of 2 . 9 years. The aggregate grant date fair value of RSUs vested during the years ended December 31, 2024 and 2023 was $ 2.2 million and $ 1.4 million, respectively. F- 21 Performance Stock Units In June 2024, the Board approved a grant of performance-based restricted stock unit awards (“PSUs" or “Performance Awards”) to the Company’s executive team. Each PSU represents the contingent right to receive one share of the Company’s common stock. These Performance Awards provide for the vesting of 25 % of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board (“Performance Milestones”), subject to the grantee’s continued service with the Company (the “Approval Conditions”). The Performance Milestones are tied to the achievement of certain business objectives and are non-market and non-financial in nature. The Board will determine that all Approval Conditions have been satisfied and the number of units that will ultimately vest on the 2026 Evaluation Date, which will occur in the first quarter of 2026, and the 2027 Evaluation Date, which will occur in the first quarter of 2027. A maximum of 25 % of the target number of RSUs may vest at the 2026 Evaluation Date and the percentage of the target number of RSUs allocable to any Performance Milestone that has not been achieved on or prior to the 2027 Evaluation Date shall be cancelled. The Company granted 2,165,325 PSUs during the year ended December 31, 2024 with a weighted average grant date fair value of $ 7.51 per unit. During the year ended December 31, 2024, the Company recognized $ 2.2 million in expense for these grants. As of December 31, 2024, there was $ 5.9 million of unrecognized equity-based compensation cost related to nonvested PSUs based on the achievement of all Performance Milestones. The Company expects to recognize this cost over a weighted average period of 1. 9 years. 10. Leases The Company has operating leases for laboratory and office space in Massachusetts and North Carolina. In June 2021, the Company entered into a lease with Hood Park LLC (“Landlord”), pursuant to which the Company leases approximately 49,869 square feet of office, laboratory, research and development and manufacturing space located in Charlestown, Massachusetts (“Premises”). The Company relocated its corporate headquarters to the Premises in June 2022. The initial term of the lease commenced in June 2022 when the construction of the lessor assets was substantially completed and continues for a ten-year period, unless earlier terminated . The lease provides the Company with an option to extend the lease for an additional five-year term. The Company and the Landlord were each obligated to undertake certain improvements prior to the commencement of the lease, and significant improvements were completed as of June 2022. The monthly lease payment is approximately $ 0.3 million with annual escalation of approximately 3 %. The lease includes a $ 10.2 million construction allowance which is considered a lease incentive and included within the right-of-use asset. The Company was required to post a customary letter of credit in the amount of $ 1.8 million, subject to decrease on a set schedule, as a security deposit pursuant to the lease. On December 22, 2022, the Company entered into a sub-lease agreement (the "Sub-Lease") with Arkea Bio Corp ("Arkea"). The Sub-Lease permits use by Arkea of a portion of the space leased by the Company at 500 Rutherford Avenue in Charlestown, Massachusetts. The Company subleased approximately 12,461 square feet of the 49,869 square foot building interior space. The Sub‑Lease term originally ended on February 28, 2025. The Sub-Lease was subsequently amended by the Sub-Lease Amendment, by and between Arkea and the Company, dated May 10, 2024, to increase the subleased area to approximately 13,714 square feet and extend the term to February 29, 2028. As of December 31, 2024, minimum future lease payments for these operating and finance leases were as follows: Finance Leases Operating Leases 2025 $ 651 $ 4,176 2026 — 4,284 2027 — 4,280 2028 — 4,364 Thereafter — 17,118 Total 651 34,222 Less: Imputed Interest ( 580 ) 11,276 Total Lease Liabilities $ 1,231 $ 22,946 F- 22 The following table shows the components of lease costs: Year Ended December 31, Lease cost 2024 2023 Operating lease cost $ 4,961 $ 5,250 Finance lease cost: Amortization of right-of-use assets 441 476 Interest on lease liabilities 340 440 Sub-lease income ( 963 ) ( 1,094 ) Total lease cost $ 4,779 $ 5,072 Short-term lease and variable lease costs were not material for the years ended December 31, 2024 and 2023 . The following table shows the weighted average remaining lease term and weighted average discount rate of the Company’s leases are as follows: Year Ended December 31, 2024 2023 Weighted-average remaining lease term (in years) Operating lease 7.6 8.5 Finance lease 0.8 1.8 Weighted-average discount rate Operating lease 10.8 % 10.7 % Finance lease 22.8 % 22.8 % 11. Commitments and Contingencies Letter of Credit The Company had an outstanding letter of credit in the amount of $ 2.0 million and $ 1.8 million at December 31, 2024 and 2023, respectively, which was required as a condition of the Company’s office and laboratory leases. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with its executive officers and members of its Board of Directors that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as executive officers or directors. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification arrangements. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2024 and 2023. Legal Proceedings The Company may periodically become subject to legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which the Company is focused. The Company is not aware of any material legal proceedings or claims as of December 31, 2024 . F- 23 12. License Agreements University of Washington License Agreement In 2015, the Company entered into a license agreement with the University of Washington, acting through UW CoMotion, under which the Company obtained an exclusive, royalty-bearing, sublicensable, worldwide license under a patent application owned by the University of Washington relating to novel micro-dystrophins and all patents claiming priority to such patent to develop, manufacture, and commercialize products for use in the treatment of Duchenne and related disease indications caused by a lack of functional dystrophin. The Company has the right to grant sublicenses to third parties contingent upon written approval by the University of Washington prior to executing such sublicense, which approval may not be unreasonably withheld. In consideration for the rights granted by the agreement, the Company paid a one-time, non-refundable license fee, which was recorded as a research and development expense in 2015. The Company is required to reimburse the University of Washington for costs incurred in applying for, prosecuting and maintaining patents and pay up to an aggregate of approximately $ 1.0 million upon the achievement of certain milestones. In October 2017, the first milestone was achieved under this agreement. The milestone payment was recorded as a research and development expense in the fourth quarter of 2017. In October 2020, the license agreement was amended such that the Company was required to pay the University of Washington $ 0.4 million in connection with the execution of the Collaboration Agreement. This payment was recorded as a research and development expense in the fourth quarter of 2020. The license agreement was also amended such that the Company is required to pay an aggregate of approximately $ 3.4 million upon the achievement of certain milestones. There were no milestones achieved during the years ended December 31, 2024 and 2023 . The Company must also pay royalties of a low single digit percentage of future sales by the Company and its sublicensees of products developed under the licensed patent rights. In addition, the Company must pay an annual maintenance fee until certain milestones are achieved, at which time a minimum annual royalty requirement will replace such maintenance fee and will apply to the Company and its sublicensees. The license agreement remains in effect until the expiration of the last-to-expire patent licensed under the agreement. The Company may terminate the agreement at any time upon providing sixty days’ written notice to the University of Washington. The University of Washington may terminate the agreement upon the Company’s uncured, material breach of the agreement or if the Company enters into an insolvency-related event. The Company recorded research and development expense in the amount of $ 0.1 million and $ 0 for the years ended December 31, 2024 and 2023 , respectively, under the agreement. The University of Missouri License Agreement In 2015, the Company entered into a license agreement with the Curators of the University of Missouri (the “University of Missouri”), a public corporation of Missouri, under which the Company obtained an exclusive, royalty-bearing, sublicensable, worldwide license under certain patent and patent applications owned by the University of Missouri relating to a novel synthetic microdystrophin gene to make, sell and distribute products for use in the treatment of Duchenne and related disease indications resulting from a lack of functional dystrophin. In consideration for the rights granted by the agreement, the Company paid a one-time, non-refundable license fee, which was recorded as a research and development expense in 2015. The Company is required to reimburse the University of Missouri for costs incurred in applying for, prosecuting and maintaining the licensed patents and pay up to an aggregate of approximately $ 1.0 million upon the achievement of certain milestones for each product developed based on the licensed patents. In October 2017, the first milestone was achieved under this agreement. The milestone payment was recorded as a research and development expense in the fourth quarter of 2017. Under the agreement, in the event the Company grants a sublicenses to another party, the Company is required to pay the University of Missouri a percentage of the consideration received. The license agreement was amended such that the Company was required to pay the University of Missouri $ 0.8 million in 2021 and $ 1.3 million in 2022. These amounts were recorded as a research and development expense in the fourth quarter of 2020. The Company paid $ 0.8 million in February 2021 and $ 1.3 million in February 2022. The license agreement was also amended such that the Company is required to pay an aggregate of approximately $ 1.9 million upon the achievement of certain milestones. There were no milestones achieved during the years ended December 31, 2024 and 2023 . The Company must pay a royalty of a low single digit percentage of future sales or by its sublicensees of products developed using the licensed patents. In addition, the Company must pay an annual maintenance fee until certain milestones are achieved, after which time a minimum annual royalty will replace such maintenance fee. Under the agreement, the Company granted the University of Missouri a non-exclusive, royalty-free, irrevocable, paid-up license, with the right to grant sublicenses to non-profit, academic, educational or governmental institutions, to practice and use improvements made by the Company using the licensed patent rights, solely for non-commercial research purposes. The license agreement remains in effect until the expiration of the last-to-expire patent or the abandonment of the last to be abandoned patent application licensed under the agreement. The University of Missouri may terminate the agreement, or render the license granted thereunder non-exclusive, in individual countries if the Company’s sublicensees fail to achieve F- 24 certain milestones. The Company may terminate the license agreement at any time upon providing six months’ written notice to the University of Missouri and paying a termination fee. Each of the University of Missouri and the Company may also terminate the agreement for an uncured default or breach of the agreement by the other party. The Company’s ability to cure such breach only applies to the first two notices of such breach provided by the University of Missouri, and thereafter, the University of Missouri may terminate the agreement for the Company’s default or breach of the agreement upon thirty days’ written notice without an opportunity to cure such default or breach. The Company recorded research and development expense in the amount of $ 0.1 million and $ 0.1 million for the years ended December 31, 2024 and 2023 , respectively, under the agreement. University of Florida License Agreements In 2020, AavantiBio entered into license agreements with the University of Florida Research Foundation, Inc. (“UFRF”). Broadly, the agreements relate to FA. The Company acquired the agreements in connection with the Acquisition. In 2023, the Company entered into an additional license agreement with UFRF. Under each agreement the Company obtained an exclusive, royalty-bearing, sublicensable, world-wide license to certain patents and patent applications and a royalty-bearing non-exclusive license under the know-how, to make, have made, use, see, have sold, import and export licensed products. UFRF retains the right to practice the patent rights and know-how for internal non-commercial research, including research sponsored by commercial entities, and educational purposes. In consideration for the rights granted under each agreement, AavantiBio paid a one-time non-refundable license fee. In connection with each agreement, the Company is required to pay an annual license maintenance fee until the first commercial sale of a licensed product after which time a minimum annual royalty will replace such maintenance fees. Under each agreement, the Company is required to reimburse UFRF for costs incurred in applying for, prosecuting and maintaining patents, pay up to an aggregate of approximately $ 2.9 million upon the achievement of certain intellectual property, clinical and regulatory milestones for each licensed product under the agreement, and pay a low, single digit royalty on annual net sales by us and our sublicensees of licensed products on a licensed-product-by-licensed product basis. For any licensed product covered by both of these agreements, the Company is only obligated to make one payment for each milestone achieved and royalty payment due. Prior to the Acquisition, AavantiBio paid a single milestone fee related to the agreements of $ 0.1 million. Under each agreement, in the event the Company grants a sublicense to another party, the Company is required to pay UFRF a percentage of the consideration received. Under each agreement, the Company has the right to grant sublicenses to third parties through multiple tiers, to the extent we are in compliance with our diligence obligations under the agreement and that sublicensee is subject to the terms of such agreement. Under each agreement, the Company is obligated to use commercially reasonable efforts to develop and commercialize products covered by the licensed patent rights or know-how and to achieve certain regulatory and commercialization milestones within estimated time periods. Under the agreements entered in 2023 and 2024, the Company agreed to pay to UFRF cumulative sales milestones of up to $ 8.5 million and $ 27.0 million, respectively, upon achievement of specified commercial milestone events and tiered royalties on worldwide net sales in the low-to-mid-single digits. Under each agreement, UFRF controls the prosecution and maintenance of the licensed patents in consultation with the Company and at the Company's expense. In countries in which the Company has not requested prosecution or maintenance of licensed patents in a particular country or jurisdiction, the license granted to such patent rights will terminate in such country or jurisdiction. The Company has the first right to enforce such licensed patents at our expense. Each of the agreements terminates on a licensed product-by-licensed product basis on the later of: (i) expiration of the patent rights covering such licensed product or (ii) ten years from the first commercial sale of such licensed product. After five years , the Company may terminate an agreement for any reason giving advance written notice and reason for termination. UFRF may terminate an agreement for our uncured default or breach of the agreement. UFRF may immediately terminate an agreement if we bring or assist others in bringing a patent challenge against of the licensed patent rights. If UFRF sends the Company a written demand to terminate a sublicense agreement due to such sublicensee bringing or assisting a patent challenge, UFRF may terminate such agreement if we do not terminate the license with such sublicensee. Maugeri License Agreement On June 29, 2023, the Company entered into a license agreement (the "Maugeri License Agreement"), with ICS Maugeri S.p.A. SB ("Maugeri"), to focus on the development and commercialization of cardiac-related products by the Company based on Maugeri’s inventions. Pursuant to the Maugeri License Agreement, Maugeri granted us an exclusive worldwide sublicensable license in certain Maugeri patent rights, including existing patent rights, and those in any improvements or know-how made in performance of the Maugeri License Agreement, and a non-exclusive worldwide sublicensable license in F- 25 certain Maugeri know-how, including existing know-how, and on any improvement thereto, in each case, subject to certain conditions, that is necessary or reasonably useful to develop the licensed products under the terms of the Maugeri License Agreement. The Company will conduct certain activities agreed to by the parties with respect to the research and development of licensed products. A condition precedent to the effectiveness of the Maugeri License Agreement was regulatory review in Italy, which was completed in the third quarter of 2023 and, upon the completion of the condition precedent, the Maugeri License Agreement became effective. The Company paid Maugeri an upfront license fee of € 1.5 million, which was recorded as research and development expense during the second quarter of 2023. Additionally, the Company agreed to cumulative developmental, regulatory, and commercial milestone payments of up to € 15.0 million, cumulative sales milestone payments of up to € 15.0 million, upon achievement of specified milestone events, and tiered royalties on worldwide net sales in the low-to-mid-single-digits. There were no milestones achieved during the years ended December 31, 2024 and December 31, 2023. The Maugeri License Agreement continues until the latest expiry of (i) the last valid claim (as defined in the Maugeri License Agreement), (ii) regulatory exclusivity, and (iii) all payment obligations. Either party may terminate the Maugeri License Agreement for the other party’s uncured material breach. The Company may also terminate the Maugeri License Agreement in its sole discretion upon 60 days ’ prior written notice to Maugeri and payment of a fee . Mayo Clinic Collaboration and License Agreement In December 2024, the Company entered into a collaboration, patent and know-how license agreement with the Mayo Foundation for Medical Education and Research (the “Mayo”) to further advance the Company's research and development efforts in the field of genetic therapies, particularly for rare and debilitating cardiac diseases. As part of the collaboration, the Company will be providing manufactured viral materials and CMC know-how while the Mayo will be responsible for supporting all preclinical research through IND-enabling studies for six programs. The Company will then be responsible for the clinical development of programs chosen by it to develop. Under the terms of the collaboration, the Company and Mayo agreed to share intellectual property rights arising from the collaboration, with the Company retaining exclusive rights to commercialize any resulting therapies. In connection with the agreement, the Company paid a one-time upfront payment of $ 0.6 million in cash and $ 2.0 million of shares of its common s tock to Mayo, which were recorded to research and development expense in the fourth quarter of 2024 having no alternative future use. Additionally, Mayo is eligible for cumulative developmental milestones of $ 5.0 million, cumulative regulatory milestones of $ 2.0 million, and cumulative sales milestone payments of up to $ 18.0 million, upon achievement of specified milestone events, and tiered royalties on worldwide net sales in the low-to-high-single-digits for certain licensed products developed by the Company. The Company also agreed to pay an annual $ 0.6 million know-how access fee to Mayo. There were no milestones achieved during the year ended December 31, 2024. The agreement also includes provisions for the potential sublicensing of certain intellectual property rights. The Company will also be responsible for reimbursing Mayo for costs incurred in the prosecution and maintenance of any patents resulting from the collaboration. The collaboration remains in effect for the duration of the intellectual property rights associated with any therapies developed under the agreement. Either party may terminate the agreement with proper notice should specific terms be breached or should an insolvency-related event occur. Other Agreements The Company has committed to make potential future milestone payments and pay legal fees to third parties as part of licensing and development programs. The agreements generally required an upfront license fee and, under each agreement, the Company may be required to pay annual maintenance fees, royalties, milestone payments and sublicensing fees. Each license agreement is generally cancelable by the Company, given appropriate prior written notice. At December 31, 2024, potential future milestone payments under these agreements totaled an aggregate of $ 18.1 million. None of these milestones were assessed to be probable as of December 31, 2024 . F- 26 13. Net Loss per Share The following table sets forth the computation of the Company's basic and diluted net loss per share: Year Ended December 31, 2024 2023 Numerator: Net loss $ ( 124,697 ) $ ( 96,015 ) Denominator: Shares used to compute net loss per share, basic and diluted Weighted average shares of common stock outstanding 38,178,327 19,884,007 Weighted average pre-funded warrants to purchase shares of common stock 2,638,367 — Weighted average shares of common stock used to compute basic and diluted net loss per share 40,816,694 19,884,007 Net loss per share, basic and diluted $ ( 3.06 ) $ ( 4.83 ) Included within weighted average shares of common stock outstanding for the year ended December 31, 2024 are 2,712,478 shares of common stock issuable upon the exercise of the pre-funded warrants as the pre-funded warrants are exercisable at any time for nominal consideration, and as such, the shares are considered outstanding for the purpose of calculating basic and diluted net loss per share. There were no pre-funded warrants issued and outstanding during the year ended December 31, 2024. The outstanding securities presented below were excluded from the calculation of net loss per share because the inclusion of such securities would have been anti-dilutive due to the Company’s net loss per share during the periods presented. Year Ended December 31, 2024 2023 Options to purchase common stock 2,927,937 2,259,672 Nonvested restricted stock units 1,480,272 877,181 Nonvested performance stock units 2,165,325 — Shares subject to employee stock purchase plan 281,640 — Warrants 9,230 — Total 6,864,404 3,136,853 14. Income Taxes The Company recorded no tax benefit for the years ended December 31, 2024 and 2023 for the net operating losses incurred due to its uncertainty of realizing a benefit from those items. F- 27 A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations as of December 31, 2024 and 2023 is as follows: December 31, 2024 2023 Income tax computed at federal statutory tax rate 21.0 % 21.0 % State taxes, net of federal benefit 6.6 % 6.6 % Permanent differences ( 0.1 )% ( 0.5 )% Tax credits 6.3 % 7.0 % Change in deferred tax rate ( 2.5 )% 0.2 % Stock compensation cancelations ( 0.2 )% ( 1.0 )% Impact of ownership change — ( 108.5 )% Other items 0.2 % 0.4 % Valuation allowance ( 31.3 )% 74.8 % Total — — The Company established deferred tax assets and liabilities on identified book to tax temporary differences as of the date of conversion to a C-corporation. Deferred income taxes reflect the net tax effects of these temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s net deferred tax assets as of December 31, 2024 and 2023 are as follows: December 31, 2024 2023 Deferred tax assets: Tax loss carryforwards $ 37,183 $ 16,622 Tax credit carryforwards 15,324 7,537 Deferred expenses 6,067 6,755 Accrued expenses 1,536 1,506 Stock compensation 9,986 8,496 Intangible assets 2,535 203 Capitalized R&D 63,087 57,133 Depreciation — 672 Derivative liabilities 833 — Other 53 80 Total deferred tax assets 136,604 99,004 Valuation allowance ( 130,690 ) ( 91,705 ) Deferred tax liabilities: Right-of-use asset ( 5,570 ) ( 7,299 ) Depreciation ( 344 ) — Total deferred tax liabilities ( 5,914 ) ( 7,299 ) Net deferred taxes $ — $ — As of December 31, 2024 , the Company had federal net operating loss carryforwards of $ 133.3 million which may be available to offset future taxable income and do not expire but are limited in their usage to an annual deduction equal to 80 % of annual taxable income. In addition, as of December 31, 2024 , the Company had state net operating loss carryforwards of approximately $ 146.5 million which may be available to offset future taxable income, of which $ 143.3 million begins to expire in 2032 and $ 3.2 million has unlimited carryforward. The Company also had federal and state tax credits of $ 13.1 million and $ 2.8 million, respectively, which may be used to offset future tax liability and each of which begin to expire in 2037 . The Company’s ability to utilize these federal and state carryforwards may be limited in the future if the Company experiences an ownership change pursuant to Section 382 of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). Ownership changes, as defined in the Internal Revenue Code, including those resulting from the issuance of common stock in connection with the Company’s public offerings, may limit the amount of net operating loss and tax credit carryforwards that can be utilized to offset future taxable income or tax liability. The Company completed a study in 2023 to assess whether a change of control had occurred under Section 382, and it was determined that all net operating loss carryforwards and credits generated before December 2, 2022 are limited. As a result, the carryforwards before the ownership change date of December 2, 2022 are not available for utilization and have been written off. The carryforwards as of December 31, 2024 were generated after the ownership change of December 2, 2022. F- 28 A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. The Company has evaluated the positive and negative evidence bearing upon the realizability of the deferred tax assets. The Company concluded, in accordance with the applicable accounting standards, that it is more likely than not that the Company will be unable to realize the benefit of its deferred tax assets. Accordingly, the Company has recorded a full valuation allowance against its deferred tax assets. The following table presents the changes in the balance of the Company’s deferred income tax asset valuation allowance : December 31, 2024 2023 Valuation allowance at beginning of year $ 91,705 $ 163,566 Increases (decreases) recorded to income tax provision 38,985 ( 71,861 ) Valuation allowance at end of year $ 130,690 $ 91,705 The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending income tax examinations. The Company’s C-Corporation tax years beginning with the year ended December 31, 2020 are open under statute. Any tax credit or net operating loss carryforward can be adjusted in future periods after the respective year of generation’s statute of limitation has closed. As of December 31, 2024 and 2023 , the Company did no t have unrecognized tax benefits. The Company recognizes interest and penalties related to income taxes as a component of income tax expense. As of December 31, 2024 and 2023 , no interest and penalties have been recorded. 15. Defined Contribution Plan The Company has a defined contribution savings plan under Section 401(k) of the Internal Revenue Code. The plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pretax basis. Company contributions to the plan may be made at the discretion of the Company’s Board of Directors. The Company made $ 0.6 million of contributions during each of the years ended December 31, 2024 and 2023 . 16. Restructuring In November 2022, the Company’s Board of Directors approved a plan to reduce the Company’s workforce by approximately 18 percent. These reductions were completed by December 5, 2022. This plan was designed to streamline the Company’s operating structure following the Acquisition. The Company recorded a restructuring charge in the fourth quarter of 2022 of $ 5.7 million related to the reduction in force, consisting of severance and other employee termination benefits. The Company paid the remaining $ 0.3 million of this amount during the year ended December 31, 2024. The following table shows the balance of accrued restructuring charges and the changes in the accrued amounts in connection with the associated restructuring plans for the years ended December 31, 2024 and 2023: One-Time Employee Termination Benefits November 2022 Accrued restructuring charges as of December 31, 2022 $ 3,921 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 3,669 ) Accrued restructuring charges as of December 31, 2023 $ 252 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 252 ) Accrued restructuring charges as of December 31, 2024 $ — 17. Segment Reporting The Company has one reportable and one operating segment and manages its business activities primarily in North America and on a consolidated basis. The Company’s singular focus is on developing treatments through gene therapy and other means for patients with neuromuscular and cardiac diseases. All of the Company’s tangible assets are held in the United States. F- 29 The accounting policies of the Company are the same as those described in the summary of significant accounting policies. The Company’s chief operating decision maker ("CODM") is its chief executive officer . The CODM assesses performance for the Company and decides how to allocate resources based on net loss as reported on the consolidated statements of operations. The annual budgeting process is the primary mechanism used to make these decisions. The financial information also helps in making performance assessments using budgeted versus actual results. The following table presents segment expenses, other segment items, and segment net loss for the periods presented: Year Ended December 31, 2024 2023 Segment Expenses: SGT-003 15,197 20,856 SGT-501 17,223 3,200 External R&D other 10,580 7,907 Internal R&D expense (1) 21,705 21,798 External G&A expense 20,122 19,635 Internal G&A expense (1) 12,223 10,911 Other segment items (2) 32,678 19,945 Other income, net ( 5,031 ) ( 8,237 ) Consolidated net loss ( 124,697 ) ( 96,015 ) (1) Internal expenses consisted primarily of payroll and related costs, temporary services, and travel and entertainment. (2) Other segment items primarily included equity-based compensation expense, other program costs, and depreciation and amortization expense The measure of segment assets is reported on the balance sheet as total consolidated assets. 18. Subsequent Events On February 19, 2025, the Company issued and sold 35,739,810 shares of its common stock at a price of $ 4.03 per share, and, to certain investors in lieu of shares of common stock, pre-funded warrants to purchase 13,888,340 shares of its common stock at a price of $ 4.029 per pre-funded warrant, in the February 2025 Offering. The Company received approximately $ 187.5 million of aggregate net proceeds from the February 2025 Offering, after deducting underwriting discounts and commissions and estimated offering costs. Following the FDA's clearance of the Company's IND application for SGT-212 for the treatment of FA , a $ 5.0 million development milestone became payable to FA212. On February 28, 2025, the Company made the first milestone payment in the form of 975,496 shares of its common stock. F- 30