X0306 4 2021-04-15 0 0001785173 89bio, Inc. ETNB 0001278219 Zoth Lota S. C/O 89BIO, INC. 142 SANSOME STREET, 2ND FLOOR SAN FRANCISCO CA 94104 1 0 0 0 Stock Option (Right to Buy) 24.16 2021-04-15 4 A 0 12500 0.00 A 2031-04-15 Common Stock 12500 12500 D This option represents a right to purchase a total of 12,500 shares of the Issuer's Common Stock, one third of which will vest on April 15, 2022, with the remaining two thirds vesting in equal monthly installments over the following two years, subject to the Reporting Person's continued service to the Issuer through each vesting date. /s/ Ryan A. Murr, as attorney-in-fact for Lota S. Zoth 2021-04-19