X0609 4 2026-06-05 0001382101 SUTRO BIOPHARMA, INC. STRO 0001891841 Hunter Heidi false C/O SUTRO BIOPHARMA, INC. 111 OYSTER POINT BLVD. SOUTH SAN FRANCISCO CA 94080 true false false false 0 Stock Option (right to buy) 26.09 2026-06-05 4 A 0 10000 0 A 2036-06-05 Common Stock 10000 10000 D The option shall vest, subject to the reporting person's provision of service to the issuer on each vesting date, as to 8.33% of the total award monthly, with the first tranche vesting on July 5, 2026, and the award shall be fully vested and exercisable on the earlier of (i) the date of the issuer's 2027 annual stockholders meeting or (ii) June 5, 2027. /s/ David Pauling as attorney-in-fact 2026-06-09