X0306 4 2021-01-19 0 0001377121 Protagonist Therapeutics, Inc PTGX 0001120477 PATEL DINESH V PH D C/O PROTAGONIST THERAPEUTICS, INC. 7707 GATEWAY BLVD., SUITE 140 NEWARK CA 94560 1 1 0 0 President and CEO Common Stock 2021-01-19 4 M 0 13000 4.21 A 450990 D Common Stock 2021-01-19 4 S 0 24846 24.5957 D 426144 D Stock Option (right to buy) 4.21 2021-01-19 4 M 0 13000 0.00 D 2026-04-29 Common Stock 13000 165742 D The sales reported in this Form 4 include: (a) the open market sale of 13,000 shares of common stock acquired pursuant to the exercise of options to purchase common stock; and (b) the open market sale of an additional 11,846 shares of common stock. Such transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2020. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.01 to $24.95, 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. 1/48th of the shares subject to the option vested on the last day of each month following the vesting commencement date. The option became fully vested on April 25, 2020. /s/ Donald A. Kalkofen, Attorney-in-Fact for Dinesh V. Patel, Ph.D. 2021-01-20