Item 8.01 Other Events. On May 15, 2025, Solid Biosciences Inc. (the “ Company”) filed a prospectus supplement (the “ Prospectus Supplement”) under the Company’s universal shelf registration statement on Form S-3 (File No. 333-277871) that was originally filed with the Securities and Exchange Commission (the “ SEC”) on March 13, 2024 and was declared effective by the SEC on May 17, 2024 (the “ Registration Statement”), relating to the offer and sale of a total of up to $85.0 million of shares of the Company’s common stock, par value $0.001 per share (the “ Shares”), pursuant to an Amended and Restated Sales Agreement, dated March 13, 2024, with Jefferies LLC (the “ Sales Agreement”). The Company had filed a prior prospectus with the SEC on March 13, 2024 (the “ Prior Prospectus”) relating to the offer and sale of shares of the Company’s common stock having an aggregate offering price of up to $75.0 million pursuant to the Sales Agreement. As of the date of the Prospectus Supplement, the Company had issued and sold shares of common stock for aggregate gross sale proceeds of approximately $10.5 million pursuant to the Sales Agreement and the Prior Prospectus. Upon the filing of the Prospectus Supplement, the Company will not make any offers or sales of its common stock pursuant to the Prior Prospectus. Wilmer Cutler Pickering Hale and Dorr LLP, counsel to the Company, has issued a legal opinion relating to the Shares. A copy of such legal opinion, including the consent included therein, is attached as Exhibit 5.1 hereto. The Shares are registered pursuant to the Registration Statement and the base prospectus contained therein, and offerings for the Shares will be made only by means of the Prospectus Supplement. This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state or jurisdiction.

Item 9.01 Financial Statements and Exhibits. (d) Exhibits: Number Description 5.1Opinion of Wilmer Cutler Pickering Hale and Dorr LLP 23.1Consent of Wilmer Cutler Pickering Hale and Dorr LLP (included in Exhibit 5.1) 104 Cover Page Interactive Data File (embedded within the Inline XBRL document SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. SOLID BIOSCIENCES INC Date: May, 15 2025 By: /s/ Alexander Cumbo Name: Alexander Cumbo