Item 2.02. Results of Operations and Financial Condition. On November 3, 2025, Solid Biosciences Inc. (the “ Company”) announced its financial results for the third quarter ended September 30, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form8-Kand is incorporated herein by reference. The information provided under Item 2.02 of this Current Report on Form8-K(including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended (the “ Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 7.01. Regulation FD Disclosure. On November 3, 2025, the Company announced positive new interim data from its Phase 1/2 INSPIRE DUCHENNE clinical trial. A copy of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form8-Kand is incorporated herein by reference. Also on November 3, 2025, the Company made available an updated corporate presentation on its website. The corporate presentation is furnished as Exhibit 99.2 to this Current Report on Form8-K. The information provided under Item 7.01 of this Current Report on Form8-K(including Exhibits 99.1 and 99.2) shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 8.01. Other Events. On November 3, 2025, the Company announced positive new interim data from its Phase 1/2 INSPIRE DUCHENNE clinical trial, a Phase 1/2 first-in-human, open-label, single-dose, multicenter trial designed to evaluate the safety, tolerability and efficacy of SGT-003in pediatric participants with Duchenne muscular dystrophy at a dose level of 1E14vg/kg. SGT-003is administered as a one-timeintravenous infusion, and a regulatory update.

Item 9.01. Financial Statements and Exhibits. d) Exhibits Exhibit Description No. 99.1 Press Release dated November 3, 2025 ──────────────────────────────────────────────────────────────────────────────────────────── 99.2 Solid Biosciences Inc. Presentation November 2025 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) SIGNATURES Pursuant to the requirements 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 hereunto duly authorized. SOLID BIOSCIENCES INC. Date: November 3, 2025 By: /s/ Alexander Cumbo Name: Alexander Cumbo Title: Chief Executive Officer