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 2019 Inducement Award Plan (as amended from time to time, 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 this Option Agreement. Optionee herewith delivers to the Company the full Exercise Price for the Shares.

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.

Grant of Option. Assembly Biosciences, Inc. (the “Company”), hereby grants to the Optionee named in the Notice of Grant (the "“Optionee”) an option (this “Option”) to purchase a total number of shares of Common Stock (the “Shares”) set forth in the Notice of Grant, at the exercise price per share set forth in the Notice of Grant (the “Exercise Price”) subject to the terms, definitions and provisions of the Assembly Biosciences, Inc. 2019 Inducement Award Plan (the “Plan”) adopted by the Company, which is incorporated herein by reference. Unless otherwise defined herein, the terms defined in the Plan shall have the same defined meanings in this Option.