Financial Performance - The company incurred significant net losses of $117.2 million, $74.8 million, and $53.2 million for the years ended December 31, 2019, 2018, and 2017, respectively, with an accumulated deficit of $316.3 million as of December 31, 2019[222]. - The company expects to continue incurring significant expenses and increasing operating losses for the foreseeable future as it seeks to resolve the clinical hold on IGNITE DMD and resume clinical development of SGT-001[223]. - The company has never generated revenue from product sales and does not expect to do so for the next several years, if ever[230]. - The independent registered public accounting firm expressed substantial doubt about the company's ability to continue as a going concern due to ongoing losses and the need for additional funding[234]. Regulatory Challenges - The FDA placed a clinical hold on the IGNITE DMD trial due to a serious adverse event, which may delay or terminate the clinical development plans for SGT-001[237]. - The company may face significant delays in obtaining regulatory approvals for SGT-001 due to the complexities of the approval process for novel product candidates[236]. - The company has limited experience in preparing and submitting regulatory filings, having never submitted a biologics license application (BLA) for any product candidate[246]. - Regulatory authorities may require additional clinical trials or impose restrictions on the distribution of SGT-001 if adverse side effects are identified post-approval[245]. - The FDA's accelerated approval pathway does not guarantee faster development or marketing approval for SGT-001[279]. - Changes in regulatory requirements or policies could lead to delays or rejections in obtaining marketing approval for SGT-001[258]. - The company may seek breakthrough therapy designation for SGT-001, but such designation does not assure faster regulatory review[277]. - The FDA requires a minimum of 15 years of monitoring for potential gene therapy-related delayed adverse events[268]. Development and Clinical Trials - The company anticipates needing additional funding to complete the development of SGT-001 and other product candidates, which may not be available on acceptable terms[225]. - The company may face substantial delays in clinical trials due to various factors, including reaching consensus with regulatory authorities and patient recruitment challenges[250]. - The company may encounter difficulties in enrolling patients for clinical trials, which could further delay the development of SGT-001[255]. - There is a high failure rate for gene therapy products in clinical trials, and success in early trials does not guarantee positive outcomes in later stages[249]. Manufacturing and Supply Chain - Manufacturing processes for SGT-001 are complex and have not been validated for commercial use, posing risks for production and regulatory approval[296]. - The company currently relies on third-party manufacturers for SGT-001 supply, which may lead to production delays if issues arise[297]. - Compliance with cGMP requirements is critical, and any issues identified during FDA inspections could disrupt production or lead to penalties[305]. - The company currently lacks long-term supply or manufacturing arrangements for the production of SGT-001 at commercial scale, which may hinder future production capabilities[307]. Market and Competition - The company faces significant competition in the biopharmaceutical market, with larger companies having more resources and experience in obtaining regulatory approvals[289]. - There are several companies, including Pfizer and Sarepta Therapeutics, developing gene therapies for Duchenne Muscular Dystrophy (DMD), which could impact the commercial opportunity for SGT-001[290]. - The potential market for SGT-001 may be smaller than anticipated, adversely affecting revenue prospects[312]. - The potential for competition remains even with orphan drug exclusivity, as regulatory authorities may authorize different drugs for the same condition[276]. Intellectual Property Risks - The company relies heavily on in-licensed patents for the development of SGT-001, and failure to comply with licensing obligations could lead to significant damages[377]. - The company may face challenges in obtaining adequate patent protection for SGT-001 and other product candidates, as patents may expire before commercialization[393]. - There is a risk that licensed patents may be challenged, narrowed, or invalidated, which could result in loss of competitive advantage[394]. - The company may be involved in legal proceedings that could affect the validity and enforceability of its patent rights, impacting its ability to commercialize products[395]. Operational and Strategic Challenges - The company announced a workforce reduction of approximately one third in January 2020 as part of a strategic plan to create a leaner organization focused on advancing SGT-001[339]. - The company may face significant market and economic disruption if no trade agreement is reached between the United Kingdom and the European Union by the end of the transitional period[331]. - The company is highly dependent on key employees, and the loss of such personnel could adversely impact the achievement of its objectives[337]. - The company may incur increased operating expenses and cash requirements if it engages in future acquisitions or strategic collaborations[335]. Compliance and Legal Risks - Compliance with various federal and state healthcare laws is critical, as violations could result in substantial penalties and operational disruptions[362]. - The company is subject to numerous environmental, health, and safety laws, which may lead to significant fines or penalties if not complied with[372]. - Internal computer systems are vulnerable to security breaches, which could disrupt product development and business operations[375]. - A material disruption from a cyber-attack could result in significant delays in regulatory approval efforts and increase costs to recover lost data[376].

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38360 Solid Biosciences Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 90-0943402 (State or other juris ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 For the quarterly period ended June 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38360 Solid Biosciences Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 90-0943402 (State or other jurisdiction of incorporation or organization) FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to (I.R.S. Employer Identification No.) Registrant's telephone number, including area code: (617) 337-4680 Indicate by check mark whether the registrant (1) has ...

Financial Performance - The company incurred significant net losses of $74.8 million, $53.2 million, and $23.8 million for the years ended December 31, 2018, 2017, and 2016, respectively, with an accumulated deficit of $199.1 million as of December 31, 2018[218]. - The company has never generated revenue from product sales and does not expect to do so for the next several years, if ever[226]. - The independent registered public accounting firm has raised substantial doubt about the company's ability to continue as a going concern due to ongoing losses and funding needs[229]. Funding and Capital Requirements - The company expects to need additional funding to complete the development of SGT-001 and other product candidates, with cash reserves projected to last through the first quarter of 2020[221]. - The company may seek additional capital through public and private equity offerings, which could dilute existing stockholders[223]. - The company’s future capital requirements will depend on various factors, including the success of clinical trials and regulatory approvals[222]. Clinical Development and Regulatory Risks - The company anticipates continued significant expenses and increasing operating losses as it progresses with clinical development of SGT-001 and other product candidates[219]. - The company faces risks related to the regulatory approval process for SGT-001, which is based on novel technology and may take longer and be more expensive than anticipated[230]. - The company has experienced a full clinical hold on SGT-001 due to an unexpected serious adverse event, which could delay further clinical trials[235]. - The company has limited experience in preparing and submitting regulatory filings, which may delay the clinical trial process for SGT-001[240]. - There is a high failure rate for gene therapy products in clinical trials, and success in preclinical studies does not guarantee future results[242]. - Regulatory authorities may impose additional requirements or restrictions on SGT-001, affecting its commercialization prospects[253]. - The FDA placed a full clinical hold on SGT-001 in March 2018 due to an unexpected serious adverse event, leading to protocol changes including the addition of IV glucocorticoids[241]. Manufacturing and Supply Chain Challenges - The company has limited gene transfer manufacturing experience, which could lead to production problems and delays in obtaining regulatory approval for SGT-001[285]. - The manufacturing process for SGT-001 is complex and has not been validated for commercial use, requiring substantial investment and time to establish a compliant facility[285]. - The company currently relies on third-party manufacturers for SGT-001 supply, which poses risks of production delays and insufficient quantities due to various factors[286]. - There is no long-term supply or manufacturing arrangement in place for SGT-001 at commercial scale, which could disrupt production if demand increases[295]. Market and Competitive Landscape - The company operates in a highly competitive biopharmaceutical market, facing competition from larger pharmaceutical and biotechnology companies, which may adversely affect its ability to market SGT-001 and other product candidates[278]. - The estimated market opportunities for SGT-001 may be smaller than anticipated, potentially affecting revenue prospects[299]. - The commercial success of SGT-001 will depend on market acceptance by physicians, patients, and third-party payors, which may be influenced by ethical, social, medical, and legal concerns[303]. Intellectual Property and Legal Risks - The company relies on in-licensed patents and intellectual property rights for the development of SGT-001, and failure to comply with licensing obligations could lead to significant damages and loss of rights[360]. - The company currently does not own any issued patents and has pending applications, which may not result in effective patent protection for its product candidates[367]. - The company may face challenges in negotiating licenses for third-party intellectual property rights necessary for the development of its product candidates[365]. - The biotechnology and pharmaceutical industries are characterized by extensive litigation regarding patents, and the company may face legal proceedings alleging infringement of third-party intellectual property rights[391]. - The company may face significant financial liabilities if unsuccessful in defending against patent infringement claims[416]. Regulatory Environment and Compliance - The regulatory environment in the United States and European Union will significantly affect the commercialization of SGT-001, with potential delays due to compliance issues[320]. - The company is required to comply with the Physician Payment Sunshine Act, which imposes new reporting and disclosure requirements that may incur additional costs[334]. - Legislative changes, such as the Health Care Reform Law, may increase costs and difficulties in obtaining marketing approval and could negatively impact pricing strategies[330]. Employee and Operational Risks - Retaining key employees is crucial for the company's success, as the loss of key personnel could impede research and development objectives[325]. - The company is experiencing intense competition for skilled personnel in gene therapy, which may hinder recruitment efforts[326]. - Employee misconduct poses risks, including non-compliance with FDA regulations, which could lead to significant liabilities and harm to the company's reputation[328].

© 2019 Solid Biosciences 1 Solid Biosciences Corporate Overview January 2019 Forward-Looking Statements This presentaDon includes "forward-looking statements" within the meaning of the Private SecuriDes LiDgaDon Reform Act of 1995, which involve a number of risks and uncertainDes. These forward-looking statements include all maOers that are not historical facts and, without limiDng the foregoing, can be idenDfied by the use of forward-looking terminology, including the terms "believe," "esDmate," "project," ...