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 [[Organization A:Organization]] (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 right to purchase shares of the Common Stock, $0.001 par value per share (the “Shares”), of [[Organization A:Organization]] (the “Company”) at $ per share pursuant to the Company’s 2018 Equity Incentive Plan and a stock option agreement with the Company 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 right to purchase shares of the Common Stock, $0.0001 par value per share (the “Shares”), of [[Organization A:Organization]] (the “Company”) at $ per share pursuant to the Company’s 2015 Equity Incentive Plan and a stock option agreement with the Company 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 ("Optionee") hereby elects to exercise Optionee's option to purchase ​ shares of the Common Stock (the "Shares") of Assembly Biosciences, Inc. (the "Company") under and pursuant to the Company's Amended and Restated 2014 Stock Incentive Plan, as amended (the "Plan") and the Notice of Stock Option Grant dated ​, 20​ with its attached Stock Option Agreement (the "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 (“Employee”) hereby elects to exercise Employee’s option to purchase shares of the Common Stock (the “Shares”) of Protagonist Therapeutics, Inc. (the “Company”) under and pursuant to [[Organization A:Organization]]’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 [[Organization A:Organization]] the full Exercise Price for the Shares.

Exercise of Option. Effective as of today, , 20 , the undersigned (“Optionee”) hereby elects to exercise Optionee’s option to purchase shares of the Common Stock (the “Shares”) of Protagonist Therapeutics, Inc. (the “Company”) under and pursuant to [[Organization A:Organization]]’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 [[Organization A:Organization]] the full Exercise Price for the Shares.

This Incentive Stock Option Agreement (the “Agreement”) evidences the grant by [[Organization A:Organization]], a Delaware corporation (the “Company”), on [ , 20 ] (the “Grant Date”) to ​, an employee of the Company (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, $0.001 par value per share, of the Company (“Common Stock”) at $​ per Share. Unless earlier terminated, this option shall expire at 5:00 p.m., Eastern time, on [ , 20 ] [date is ten years minus one day from grant date] (the “Final Exercise Date”).