X0306 4 2022-01-29 0 0001382101 SUTRO BIOPHARMA, INC. STRO 0001877585 Vasquez Nicki C/O SUTRO BIOPHARMA, INC. 111 OYSTER POINT BLVD. SOUTH SAN FRANCISCO CA 94080 0 1 0 0 Chief Port. Strat & Alnce Ofcr Common Stock 2022-01-29 4 M 0 2500 0.00 A 9770 D Common Stock 2022-01-29 4 F 0 1024 10.39 D 8746 D Restricted Stock Unit (RSU) 2022-01-29 4 M 0 2500 0.00 D 2025-01-29 Common Stock 2500 5000 D Represents the number of shares of Common Stock that have been withheld by the issuer to satisfy its income tax withholding and remittance obligations in connection with the net settlement of the RSUs and does not represent a sale by the reporting person. Each RSU represents a contingent right to receive one (1) share of the issuer's Common Stock upon settlement. The RSUs vest as to 1/4th of the total shares annually beginning on January 29, 2021, subject to continued service through each vesting date. /s/ Edward C. Albini as attorney-in-fact for Nicki Vasquez 2022-02-01