Exercise of Option. Effective as of today, , , the undersigned (“Participant”) hereby elects to exercise Participant’s option (the “Option”) to purchase shares of the Common Stock (the “Shares”) of ​ (the “Company”) under and pursuant to the 2015 Equity Incentive Plan (the “Plan”) and the Stock Option Agreement dated , (the “Option Agreement”).

I, (the “Participant”), ,hereby irrevocably exercise the undersigned (“Participant”) hereby elects to exercise Participant’s option (the “Option”)right to purchase shares of the Common StockStock, ​ par value per share (the “Shares”), of ​ (the “Company”) under andat $ per share pursuant to the 2015Company’s 2018 Equity Incentive Plan (the “Plan”) and a stock option agreement with the Stock Option AgreementCompany dated , (the “Option Agreement”). Enclosed herewith is a payment of $ , the aggregate purchase price for the Shares. The certificate for the Shares should be registered in my name as it appears below or, if so indicated below, jointly in my name and the name of the person designated below, with right of survivorship.

I, (the “Participant”), ,hereby irrevocably exercise the undersigned (“Participant”) hereby elects to exercise Participant’s option (the “Option”)right to purchase shares of the Common StockStock, ​ par value per share (the “Shares”), of ​ (the “Company”) under andat $ per share pursuant to the Company’s 2015 Equity Incentive Plan (the “Plan”) and a stock option agreement with the Stock Option AgreementCompany dated , (the “Option Agreement”). Enclosed herewith is a payment of $ , the aggregate purchase price for the Shares. The certificate for the Shares should be registered in my name as it appears below or, if so indicated below, jointly in my name and the name of the person designated below, with right of survivorship.

Exercise of Option. Effective as of today, , , the undersigned (“Participant”("Optionee") hereby elects to exercise Participant’Optionee's option (the “Option”) to purchase ​ shares of the Common Stock (the “Shares”"Shares") of ​Assembly Biosciences, Inc. (the “Company”"Company") under and pursuant to the 2015 EquityCompany's Amended and Restated 2014 Stock Incentive PlanPlan, as amended (the “Plan”"Plan") and the Notice of Stock Option Grant dated ​, 20​ with its attached Stock Option Agreement dated , (the “Option Agreement”"Option Agreement"). The purchase price for the Shares shall be ​ as required by the Option Agreement. Optionee herewith delivers to the Company the full Exercise Price for the Shares.

Exercise of Option. Effective as of today, , , the undersigned (“Participant”Employee”) hereby elects to exercise Participant’Employee’s option (the “Option”) to purchase shares of the Common Stock (the “Shares”) of ​Protagonist Therapeutics, Inc. (the “Company”) under and pursuant to the 2015 Equity​’s 2007 Stock Option and Incentive Plan (the “Plan”) and the Stock Option Agreement dated , (the “Option Agreement”). The purchase price for the Shares shall be $ as required by the Option Agreement. Employee herewith delivers to ​ the full Exercise Price for the Shares.

Exercise of Option. Effective as of today, , 20 , the undersigned (“Participant”Optionee”) hereby elects to exercise Participant’Optionee’s option (the “Option”) to purchase shares of the Common Stock (the “Shares”) of ​Protagonist Therapeutics, Inc. (the “Company”) under and pursuant to the 2015 Equity​’s 2007 Stock Option and Incentive Plan (the “Plan”) and the Stock Option Agreement dated , (the “Option Agreement”). The purchase price for the Shares shall be $ as required by the Option Agreement. Optionee herewith delivers to ​ the full Exercise Price for the Shares.

This Incentive Stock Option Agreement (the “Agreement”) evidences the grant by ​, a Delaware corporation (the “Company”), on [ , the undersigned (“Participant”) hereby elects to exercise Participant’s option20 ] (the “Option”“Grant Date”) to purchase shares​, an employee of the CommonCompany (the “Participant”), of an option to purchase, in whole or in part, on the terms provided herein and in the Company’s 2015 Stock Incentive Plan (the “Plan”), a total of ​ shares (the “Shares”) of ​common stock, ​ par value per share, of the Company (“Common Stock”) at $​ per Share. Unless earlier terminated, this option shall expire at ​, Eastern time, on [ , 20 ] [date is ten years minus one day from grant date] (the “Company”) under and pursuant to the 2015 Equity Incentive Plan (the “Plan”) and the Stock Option Agreement dated , (the “Option Agreement”“Final Exercise Date”).