Nature of the Business and Basis of Presentation	6 Months Ended
Jun. 30, 2022
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	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”). The Company’s mission is to cure Duchenne muscular dystrophy (“Duchenne”), a genetic muscle-wasting disease predominantly affecting boys. It is caused by mutations in the dystrophin gene, which result in the absence or near-absence of dystrophin protein. Dystrophin protein works to strengthen muscle fibers and protect them from daily wear and tear. Without functioning dystrophin and certain associated proteins, muscles suffer excessive damage from normal daily activities and are unable to regenerate, leading to the build-up of fibrotic, or scar, and fat tissue. The Company’s two product candidates, SGT-001 and SGT-003, are gene transfer candidates under investigation for their ability to drive functional dystrophin protein expression in patients’ muscles and improve the course of the disease. SGT-001 has been granted Rare Pediatric Disease Designation and Fast Track Designation in the United States and Orphan Drug Designations in both the United States and European Union. The Company filed an Investigational New Drug application (“IND”) in September 2017 and enrolled patients in a Phase I/II clinical trial for SGT-001, called IGNITE DMD, in the United States between the fourth quarter of 2017 and the fourth quarter of 2021. In March 2022, the Company reported two-year interim safety and efficacy data from the first three patients treated with SGT-001 in the 2E14 vg/kg dose cohort of IGNITE DMD, which results suggested durable benefit compared with natural history trajectories 24 months post-administration of SGT-001 across functional, pulmonary and patient reported outcome measures. In addition, no new drug-related safety findings have been identified in patients treated with SGT-001 in IGNITE DMD in post-dosing periods of approximately six months to four years. In April 2022, the Company announced that it had concluded enrollment in IGNITE DMD. Development activities, including manufacturing scale-up, testing and regulatory discussions with the Food and Drug Administration (FDA) are ongoing. The company expects to continue dosing patients using SGT-001 in 2023 with product made using the new transient-based process. The company also expects to share additional data from IGNITE DMD in early 2023, including the study’s primary one-year analysis of all treated patients as well as three-year longitudinal data from Patients Four through Six. In May 2021, the Company announced the advancement of a next-generation Duchenne microdystrophin gene transfer program, SGT-003, a preclinical candidate that combines AAV-SLB101, a novel and rationally designed AAV capsid with the Company’s proprietary neuronal Nitric Oxide Synthase (“nNOS”) containing microdystrophin construct. AAV-SLB101 was screened in Solid’s internal development platform for enhanced muscle tropic capsids. 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. Product 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 product 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. Basis of Presentation The accompanying condensed 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 June 30, 2022, the Company has funded its operations primarily with the proceeds from the sale of redeemable preferred units and member units, the sale of common stock and prefunded warrants to purchase shares of its common stock in private placements, the sale of common stock in its initial public offering and follow-on public offering in March 2021 and sales of common stock under an at-the-market sales agreement, dated March 13, 2019, as amended on August 16, 2021 (the “ATM Sales Agreement”), by and between the Company and Jefferies LLC (“Jefferies”). 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 June 30, 2022, the Company had an accumulated deficit of $527,177. During the three and six months ended June 30, 2022, the Company incurred a net loss of $25,092 and $50,420, respectively, and the Company used $43,068 of cash in operations for the six months ended June 30, 2022. 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 $162,883 as of June 30, 2022, 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 it may 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 condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed consolidated financial statements include the accounts of Solid Biosciences Inc. and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. In the opinion of management, the Company’s accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the Company’s financial statements for interim periods in accordance with GAAP. The information included in this quarterly report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The year-end condensed consolidated balance sheet data presented for comparative purposes was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. The results of operations for the three and six months ended June 30, 2022 are not necessarily indicative of the operating results for the full year or for any other subsequent interim period.

Nature of the Business and Basis of Presentation

6 Months Ended

Jun. 30, 2022

Nature of the Business and Basis of Presentation

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”).

The Company’s mission is to cure Duchenne muscular dystrophy (“Duchenne”), a genetic muscle-wasting disease predominantly affecting boys. It is caused by mutations in the dystrophin gene, which result in the absence or near-absence of dystrophin protein. Dystrophin protein works to strengthen muscle fibers and protect them from daily wear and tear. Without functioning dystrophin and certain associated proteins, muscles suffer excessive damage from normal daily activities and are unable to regenerate, leading to the build-up of fibrotic, or scar, and fat tissue. The Company’s two product candidates, SGT-001 and SGT-003, are gene transfer candidates under investigation for their ability to drive functional dystrophin protein expression in patients’ muscles and improve the course of the disease.

SGT-001 has been granted Rare Pediatric Disease Designation and Fast Track Designation in the United States and Orphan Drug Designations in both the United States and European Union. The Company filed an Investigational New Drug application (“IND”) in September 2017 and enrolled patients in a Phase I/II clinical trial for SGT-001, called IGNITE DMD, in the United States between the fourth quarter of 2017 and the fourth quarter of 2021. In March 2022, the Company reported two-year interim safety and efficacy data from the first three patients treated with SGT-001 in the 2E14 vg/kg dose cohort of IGNITE DMD, which results suggested durable benefit compared with natural history trajectories 24 months post-administration of SGT-001 across functional, pulmonary and patient reported outcome measures. In addition, no new drug-related safety findings have been identified in patients treated with SGT-001 in IGNITE DMD in post-dosing periods of approximately six months to four years. In April 2022, the Company announced that it had concluded enrollment in IGNITE DMD. Development activities, including manufacturing scale-up, testing and regulatory discussions with the Food and Drug Administration (FDA) are ongoing. The company expects to continue dosing patients using SGT-001 in 2023 with product made using the new transient-based process. The company also expects to share additional data from IGNITE DMD in early 2023, including the study’s primary one-year analysis of all treated patients as well as three-year longitudinal data from Patients Four through Six.

In May 2021, the Company announced the advancement of a next-generation Duchenne microdystrophin gene transfer program, SGT-003, a preclinical candidate that combines AAV-SLB101, a novel and rationally designed AAV capsid with the Company’s proprietary neuronal Nitric Oxide Synthase (“nNOS”) containing microdystrophin construct. AAV-SLB101 was screened in Solid’s internal development platform for enhanced muscle tropic capsids.

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. Product 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 product 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.

Basis of Presentation

The accompanying condensed 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 June 30, 2022, the Company has funded its operations primarily with the proceeds from the sale of redeemable preferred units and member units, the sale of common stock and prefunded warrants to purchase shares of its common

stock in private placements, the sale of common stock in its initial public offering and follow-on public offering in March 2021 and sales of common stock under an at-the-market sales agreement, dated March 13, 2019, as amended on August 16, 2021 (the “ATM Sales Agreement”), by and between the Company and Jefferies LLC (“Jefferies”).

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 June 30, 2022, the Company had an accumulated deficit of $527,177. During the three and six months ended June 30, 2022, the Company incurred a net loss of $25,092 and $50,420, respectively, and the Company used $43,068 of cash in operations for the six months ended June 30, 2022. 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 $162,883 as of June 30, 2022, 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 it may 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 condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed consolidated financial statements include the accounts of Solid Biosciences Inc. and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. In the opinion of management, the Company’s accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the Company’s financial statements for interim periods in accordance with GAAP. The information included in this quarterly report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The year-end condensed consolidated balance sheet data presented for comparative purposes was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. The results of operations for the three and six months ended June 30, 2022 are not necessarily indicative of the operating results for the full year or for any other subsequent interim period.