Nature of the Business and Basis of Presentation	9 Months Ended
Sep. 30, 2018
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. In October 2013, the Company changed its name to Solid Ventures, LLC and in June 2015, the Company changed its name to Solid Biosciences, LLC. The Company operated as a Delaware limited liability company under the name Solid Biosciences, LLC 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 (the “Corporate Conversion”) and changed its name to Solid Biosciences Inc. (the “Company”). As a result of the Corporate Conversion, all of the Series 1 and 2 Senior Preferred Units, Junior Preferred Units, Series A, B, C and D Common Units of Solid Biosciences, LLC converted into shares of common stock of Solid Biosciences Inc. on a one-for-0.8485 basis and all of the unit holders of Solid Biosciences, LLC became holders of common stock of Solid Biosciences Inc. The Company’s mission is to cure Duchenne muscular dystrophy (“DMD”), 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 lead product candidate, SGT-001, is a gene transfer under development to restore functional dystrophin protein expression in patients’ muscles. SGT-001 has been granted Rare Pediatric Disease Designation and Fast Track in the United States and Orphan Drug Designations in both the United States and European Union. The Company filed an Investigational New Drug application, or IND, in September 2017 and initiated a Phase I/II clinical trial for SGT-001 in the United States during the fourth quarter of 2017, which is called IGNITE DMD. In November 2017, the FDA notified the Company that it was not permitted to dose patients in the higher-dose group of IGNITE DMD due to a partial clinical hold. The partial clinical hold related to the number of vials and manufacturing lots utilized per patient, as well as manufacturing processes to support the higher-dose group. The partial clinical hold has since been resolved. In March 2018, the Company announced that IGNITE DMD was placed on full clinical hold following an unexpected serious adverse event reported in the first patient dosed in the clinical trial. The Company submitted a comprehensive response to the FDA and in June 2018, the FDA lifted the clinical hold. Since resuming in June, two additional patients, both ambulatory children, were dosed with SGT-001 in IGNITE DMD. There were no serious adverse events observed with SGT-001 administration. Laboratory findings, including a transient decline in platelet count that fully resolved, were quickly identified and managed per the study protocol. In total, six patients have been randomized in IGNITE DMD, three into the active treatment group and three to the study’s delayed treatment control group. The Company continues to enroll patients in IGNITE DMD. 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 pre-clinical 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. Initial Public Offering in January 2018 On January 30, 2018, the Company completed its initial public offering with the sale of 8,984,375 shares of common stock, including shares of common stock issued upon the exercise in full of the underwriters’ over-allotment option, at a public offering price of $16.00 per share, resulting in net proceeds of $129,096, after deducting underwriting discounts and commissions and offering expenses. Liquidity 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 September 30, 2018, the Company has funded its operations primarily with the proceeds from the private placements of preferred units and member units and its recently completed initial public offering. The Company has incurred recurring losses from operations since its inception, including a net loss of $19,020 and $13,505 for the three months ended September 30, 2018 and 2017, respectively, and $52,877 and $38,691 for the nine months ended September 30, 2018 and 2017, respectively. In addition, as of September 30, 2018, the Company had an accumulated deficit of $177,135. The Company expects to continue to generate operating losses for the foreseeable future. As of September 30, 2018, the Company had cash, cash equivalents and available-for-sale securities of $145,369. The Company believes that its cash, cash equivalents and available-for-sale securities as of September 30, 2018 will enable it to fund its operating expenses and capital expenditure requirements through at least the next 12 months from the issuance of these financial statements. To execute its business plans, the Company will need substantial funding to support its continuing operations and pursue its growth strategy. Until the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through the sale of public or private equity, debt financings or other capital sources, potentially including collaborations with other companies or other strategic transactions. The Company may not be able to obtain financing on acceptable terms, or at all. Even if the Company is able to secure financing, the terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, pre-clinical and clinical testing or commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient financing on terms acceptable to the Company to fund continuing operations, if at all. Merger and Recapitalization in March 2017 The Company had historically owned 100% of the voting units of its wholly owned subsidiary, Solid GT, LLC (“Solid GT”), and the results of Solid GT were included in the Company’s condensed consolidated financial statements. In November 2015, Solid GT issued voting units to new investors which decreased the Company’s voting ownership in Solid GT to 77%. The Company continued to consolidate the results of Solid GT into its financial statements as the Company owned a majority voting interest in Solid GT and directed the activities of Solid GT. However, because the Company controlled but owned less than 100% of Solid GT, the Company recorded a non-controlling ownership interest at its fair value at inception and recognizes the net loss or profit attributable to non-controlling interests in the condensed consolidated statements of operations based on a profit and loss sharing arrangement between the Company and the non-controlling interests. The Company also presented the change in equity related to equity-based compensation issued to Solid GT employees by Solid GT in non-controlling interest. On March 29, 2017, the Company merged the operations of Solid GT into the Company and Solid GT ceased to exist as a legal entity. The proportionate share of the loss attributed to the non-controlling interest amounted to $0 and $1,060 for the three and nine months ended September 30, 2017, respectively. There was no loss attributed to the non-controlling interest for the three and nine months ended September 30, 2018 since the merger was completed on March 29, 2017. See Note 3, Merger and Recapitalization, for additional information. 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 the Company 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 (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, 2017. 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 nine months ended September 30, 2018 are not necessarily indicative of the operating results for the full year or for any other subsequent interim period.

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. In October 2013, the Company changed its name to Solid Ventures, LLC and in June 2015, the Company changed its name to Solid Biosciences, LLC.

The Company operated as a Delaware limited liability company under the name Solid Biosciences, LLC 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 (the “Corporate Conversion”) and changed its name to Solid Biosciences Inc. (the “Company”). As a result of the Corporate Conversion, all of the Series 1 and 2 Senior Preferred Units, Junior Preferred Units, Series A, B, C and D Common Units of Solid Biosciences, LLC converted into shares of common stock of Solid Biosciences Inc. on a one-for-0.8485 basis and all of the unit holders of Solid Biosciences, LLC became holders of common stock of Solid Biosciences Inc.

The Company’s mission is to cure Duchenne muscular dystrophy (“DMD”), 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 lead product candidate, SGT-001, is a gene transfer under development to restore functional dystrophin protein expression in patients’ muscles. SGT-001 has been granted Rare Pediatric Disease Designation and Fast Track in the United States and Orphan Drug Designations in both the United States and European Union. The Company filed an Investigational New Drug application, or IND, in September 2017 and initiated a Phase I/II clinical trial for SGT-001 in the United States during the fourth quarter of 2017, which is called IGNITE DMD. In November 2017, the FDA notified the Company that it was not permitted to dose patients in the higher-dose group of IGNITE DMD due to a partial clinical hold. The partial clinical hold related to the number of vials and manufacturing lots utilized per patient, as well as manufacturing processes to support the higher-dose group. The partial clinical hold has since been resolved.

In March 2018, the Company announced that IGNITE DMD was placed on full clinical hold following an unexpected serious adverse event reported in the first patient dosed in the clinical trial. The Company submitted a comprehensive response to the FDA and in June 2018, the FDA lifted the clinical hold. Since resuming in June, two additional patients, both ambulatory children, were dosed with SGT-001 in IGNITE DMD. There were no serious adverse events observed with SGT-001 administration. Laboratory findings, including a transient decline in platelet count that fully resolved, were quickly identified and managed per the study protocol. In total, six patients have been randomized in IGNITE DMD, three into the active treatment group and three to the study’s delayed treatment control group. The Company continues to enroll patients in IGNITE DMD.

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 pre-clinical 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.

Initial Public Offering in January 2018

On January 30, 2018, the Company completed its initial public offering with the sale of 8,984,375 shares of common stock, including shares of common stock issued upon the exercise in full of the underwriters’ over-allotment option, at a public offering price of $16.00 per share, resulting in net proceeds of $129,096, after deducting underwriting discounts and commissions and offering expenses.

Liquidity

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 September 30, 2018, the Company has funded its operations primarily with the proceeds from the private placements of preferred units and member units and its recently completed initial public offering. The Company has incurred recurring losses from operations since its inception, including a net loss of $19,020 and $13,505 for the three months ended September 30, 2018 and 2017, respectively, and $52,877 and $38,691 for the nine months ended September 30, 2018 and 2017, respectively. In addition, as of September 30, 2018, the Company had an accumulated deficit of $177,135. The Company expects to continue to generate operating losses for the foreseeable future.

As of September 30, 2018, the Company had cash, cash equivalents and available-for-sale securities of $145,369. The Company believes that its cash, cash equivalents and available-for-sale securities as of September 30, 2018 will enable it to fund its operating expenses and capital expenditure requirements through at least the next 12 months from the issuance of these financial statements.

To execute its business plans, the Company will need substantial funding to support its continuing operations and pursue its growth strategy. Until the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through the sale of public or private equity, debt financings or other capital sources, potentially including collaborations with other companies or other strategic transactions. The Company may not be able to obtain financing on acceptable terms, or at all. Even if the Company is able to secure financing, the terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, pre-clinical and clinical testing or commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient financing on terms acceptable to the Company to fund continuing operations, if at all.

Merger and Recapitalization in March 2017

The Company had historically owned 100% of the voting units of its wholly owned subsidiary, Solid GT, LLC (“Solid GT”), and the results of Solid GT were included in the Company’s condensed consolidated financial statements. In November 2015, Solid GT issued voting units to new investors which decreased the Company’s voting ownership in Solid GT to 77%. The Company continued to consolidate the results of Solid GT into its financial statements as the Company owned a majority voting interest in Solid GT and directed the activities of Solid GT. However, because the Company controlled but owned less than 100% of Solid GT, the Company recorded a non-controlling ownership interest at its fair value at inception and recognizes the net loss or profit attributable to non-controlling interests in the condensed consolidated statements of operations based on a profit and loss sharing arrangement between the Company and the non-controlling interests. The Company also presented the change in equity related to equity-based compensation issued to Solid GT employees by Solid GT in non-controlling interest.

On March 29, 2017, the Company merged the operations of Solid GT into the Company and Solid GT ceased to exist as a legal entity. The proportionate share of the loss attributed to the non-controlling interest amounted to $0 and $1,060 for the three and nine months ended September 30, 2017, respectively. There was no loss attributed to the non-controlling interest for the three and nine months ended September 30, 2018 since the merger was completed on March 29, 2017. See Note 3, Merger and Recapitalization, for additional information.

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 the Company 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 (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, 2017. 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 nine months ended September 30, 2018 are not necessarily indicative of the operating results for the full year or for any other subsequent interim period.