X0306 4 2018-03-20 0 0001377121 Protagonist Therapeutics, Inc PTGX 0001619859 CANAAN X L.P. 285 RIVERSIDE AVENUE, SUITE 250 WESTPORT CT 06880 0 0 1 0 0001673228 Canaan Partners X LLC 285 RIVERSIDE AVENUE, SUITE 250 WESTPORT CT 06880 0 0 1 0 Common Stock 2018-03-20 4 S 0 17060 20.606 D 2402675 D Common Stock 2018-03-21 4 S 0 17699 20.6072 D 2384976 D Common Stock 2018-03-22 4 S 0 4759 20.6205 D 2380217 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.50 - $20.84, inclusive. The reporting persons undertake 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 set forth in this footnote. These shares are held directly by Canaan X L.P. (the "Canaan Fund"). The sole general partner of the Canaan Fund is Canaan Partners X LLC ("Canaan X", and together with the Canaan Fund, the "Canaan Entities"), and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Canaan X disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of its pecuniary interest therein, if any. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.50 - $20.79, inclusive. The reporting persons undertake 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 set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.50 - $20.87, inclusive. The reporting persons undertake 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 set forth in this footnote. Exhibit 24 - Power of Attorney (incorporated by reference to the Power of Attorney filed as Exhibit 24 to the Form 3 filed by the Reporting Persons on August 10, 2016) Canaan X L.P., By: Canaan Partners X LLC, its general partner, By: /s/ Janine MacDonald, Attorney-in-Fact 2018-03-22 Canaan Partners X LLC, By: /s/ Janine MacDonald, Attorney-in-Fact 2018-03-22