X0306 4 2021-08-09 false 0001822462 Foghorn Therapeutics Inc. FHTX 0001714023 Reine Allan 500 TECHNOLOGY SQUARE STE #700 CAMBRIDGE MA 02139 false true false false Chief Financial Officer Common Stock 2021-08-09 4 M false 26892.00 3.72 A 53784.00 D Stock Options (Right to buy) 3.72 2021-08-09 4 M false 26892.00 0.00 A 2029-09-16 Common Stock 26892.00 257512.00 D The option vested as to 25% of the underlying shares of common stock on September 16, 2020, the first anniversary of the of the vesting commencement date, and at a rate of 6.25% of the underlying shares thereafter on the first day of each calendar quarter following such first anniversary until the option is fully vested. /s /Adrian Gottschalk, Attorney-in-Fact for Allan Reine 2021-08-11