X0508 4 2026-01-27 0 0001377121 Protagonist Therapeutics, Inc PTGX 0001921163 Ali Asif C/O PROTAGONIST THERAPEUTICS, INC. 7707 GATEWAY BLVD., SUITE 140 NEWARK CA 94560-1160 0 1 0 0 Chief Financial Officer 0 Common Stock 2026-01-27 4 M 0 16000 19.19 A 94523 D Common Stock 2026-01-27 4 M 0 12000 12.17 A 106523 D Common Stock 2026-01-27 4 S 0 28000 83.13 D 78523 D Common Stock 2026-01-27 4 S 0 18203 83.14 D 60320 D Stock Option (right to buy) 19.19 2026-01-27 4 M 0 16000 0 D 2032-04-18 Common Stock 16000 50800 D Stock Option (right to buy) 12.17 2026-01-27 4 M 0 12000 0 D 2033-01-15 Common Stock 12000 18547 D Includes an aggregate of 446 shares acquired by the Reporting Person under the Issuer's 2016 Employee Stock Purchase Plan on September 9, 2025. The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $82.77 to $83.595. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $82.80 to $83.595. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price. The stock option was granted to the Reporting Person on April 18, 2022, one quarter vested on April 18, 2023 and the remaining three quarters vest in equal monthly installments through April 18, 2026, subject to the Reporting Person's continued service to the Issuer. The stock option was granted to the Reporting Person on January 16, 2023 and vests in 48 equal monthly installments following the date of grant, subject to the Reporting Person's continued service to the Issuer. /s/ Matthew Gosling, Attorney-in-Fact for Asif Ali 2026-01-27