X0407 4 2023-06-08 0 0001382101 SUTRO BIOPHARMA, INC. STRO 0001236537 MATSUI CONNIE C/O SUTRO BIOPHARMA, INC. 111 OYSTER POINT BLVD. SOUTH SAN FRANCISCO CA 94080 1 0 0 0 0 Stock Option (right to buy) 5.12 2023-06-08 4 A 0 25000 0.00 A 2033-06-08 Common Stock 25000 25000 D The option vests as to 8.33% of the total shares monthly, commencing July 8, 2023, with 100% of the total shares vested and exercisable on the earlier of the issuer's 2024 annual stockholders meeting or June 8, 2024, subject to the reporting person's provision of service to the issuer on each vesting date. /s/ Edward C. Albini as attorney-in-fact 2023-06-12