144 0001997809 XXXXXXXX LIVE 0001707502 Solid Biosciences Inc. 001-38360 500 Rutherford Avenue Charlestown MA 02129 (617)-337-4680 Brooks Gabriel Officer Common Stock ETRADE FINANCIAL CORPORATION

3 EDISON DRIVE ALPHARETTA GA 30005

12616 81267.65 82569192 02/04/2026 NASDAQ Common Stock 02/04/2026 Settlement of vested restricted stock units Issuer N 12616 02/04/2026 Compensation N Brooks Gabriel

500 Rutherford Avenue Charlestown MA 02129

Common Stock 02/02/2026 28335 182389.56 The sale reported on this Form 144 was made to cover witholding taxes following the vesting of previously granted performance stock units pursuant to a durable sale instruction letter adopted by Dr. Brooks on August 15, 2024 effecting the sell-cover-election. The sale does not represent a discretionary trade by Dr. Brooks. 02/04/2026 08/15/2024 /s/ Kimberly Cornwell as attorney-in-fact for Gabriel Brooks