X0306 4 2022-11-07 0 0001680581 Fulcrum Therapeutics, Inc. FULC 0001706857 Arroyo Santiago C/O FULCRUM THERAPEUTICS, INC. 26 LANDSDOWNE STREET CAMBRIDGE MA 02139 0 1 0 0 Chief Medical Officer Stock Option (right to buy) 5.61 2022-11-07 4 A 0 400000 0.00 A 2032-11-06 Common Stock 400000 400000 D This option was granted on November 7, 2022 and is scheduled to vest 25% on the first anniversary of the vesting commencement date of November 7, 2022. The remainder of the shares underlying the grant shall vest in equal quarterly installments over the following three years until the fourth anniversary of the vesting commencement date, subject to continued service. /s/ Greg Tourangeau, as attorney-in-fact for Santiago Arroyo 2022-11-09