SCHEDULE 13G 0001831942 XXXXXXXX LIVE Common Stock $0.001 par value per share 02/18/2025 0001707502 Solid Biosciences Inc. 83422E204 500 Rutherford Avenue 3rd Floor Charlestown MA 02129 Rule 13d-1(c) COMMODORE CAPITAL LP DE 0.00 5825000.00 0.00 5825000.00 5825000.00 N 7.6 IA See Item 2 for additional information. Commodore Capital Master LP E9 0.00 5825000.00 0.00 5825000.00 5825000.00 N 7.6 OO See Item 2 for additional information. Solid Biosciences Inc. 500 Rutherford Avenue, 3rd Floor, Charlestown, Massachusetts 02129 This report on Schedule 13G is being filed by Commodore Capital LP, a Delaware limited partnership (the "Firm") and Commodore Capital Master LP, a Cayman Islands exempted limited partnership ("Commodore Master"). The Firm is the investment manager to Commodore Master. As of February 18, 2025, the Firm may be deemed to beneficially own an aggregate of 5,825,000 shares of common stock $0.001 par value per share (the "Common Stock"), of the Issuer. The Firm, as the investment manager to Commodore Master, may be deemed to beneficially own these securities. Michael Kramarz and Robert Egen Atkinson are the managing partners of the Firm and exercise investment discretion with respect to these securities. Ownership percentages are based on 76,318,810 shares of Common Stock reported as issued and outstanding in the Issuer's Rule 424(b)(5) Prospectus filed with the Securities and Exchange Commission on February 18, 2025. The address for the Firm and Commodore Master is: 444 Madison Avenue, Floor 35, New York, New York 10022. The Firm is a Delaware limited partnership and Commodore Master is a Cayman Islands exempted limited partnership. Y 5,825,000.00 7.6 0 5,825,000.00 0 5,825,000.00 Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Exhibit 1 - JOINT FILING AGREEMENT COMMODORE CAPITAL LP /s/ Michael Kramarz 02/25/2025 Commodore Capital Master LP /s/ Michael Kramarz 02/25/2025