X0306 4 2021-01-04 0 0001707502 Solid Biosciences Inc. SLDB 0001197032 SMITH IAN F 141 PORTLAND ST. 5TH FLOOR CAMBRIDGE MA 02139 1 0 0 0 Stock Option (Right to Buy) 7.84 2021-01-04 4 A 0 389000 0.00 A 2031-01-04 Common Stock 389000 389000 D This option was granted on January 4, 2021 and will vest in equal quarterly installments beginning three months from the date of the grant with the final installment vesting date being the later of the completion of a specified service requirement under his consulting agreement or 12 months from the date of the grant, subject to continued service as a director or consultant, and in the event of a change in control, the vesting schedule of the option will accelerate in full. /s/ by Ilan Ganot as attorney-in-fact for Ian F. Smith 2021-01-06