X0306 4 2021-02-10 0 0001377121 Protagonist Therapeutics, Inc PTGX 0001706301 Noonberg Sarah B. C/O PROTAGONIST THERAPEUTICS, INC. 7707 GATEWAY BOULEVARD, SUITE 140 NEWARK CA 94560-1160 1 0 0 0 Common Stock 2021-02-10 4 A 0 4700 6.98 A 4700 D Common Stock 2021-02-10 4 S 0 4300 25.42 D 400 D Common Stock 2021-02-10 4 S 0 400 26.04 D 0 D Common Stock 2021-02-11 4 A 0 3700 6.98 A 3700 D Common Stock 2021-02-11 4 S 0 3700 25.09 D 0 D Stock Option (right to buy) 6.98 2021-02-10 4 M 0 4700 0.00 D 2028-05-28 Common Stock 4700 7300 D Stock Option (right to buy) 6.98 2021-02-11 4 M 0 3700 0.00 D 2028-05-28 Common Stock 3700 3600 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on July 1, 2020. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.01 to $25.93, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.03 to $26.08, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.00 to $25.20, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. This option is fully vested. It vested in accordance with the following schedule: the shares subject to this option shall vest at the earlier on (i) May 29, 2019, or (ii) the date of the 2019 Annual Meeting of stockholders of the Issuer, subject to the non-employee director's continuous service with the Issuer through such dates. The shares subject to this option will vest in full upon completion of a Change in Control (as defined in the Issuer's 2016 Equity Incentive Plan). /s/ Donald Kalkofen, Attorney-in-Fact for Sarah B. Noonberg 2021-02-12