Exercise of Option. This Option is exercisable during its term in accordance with the Vesting Schedule contained in the Notice and the applicable provisions of the Grant Agreement and subject to compliance with all Applicable Laws. Grantee may exercise the vested portion of this Option only by following the option exercise procedures established by the Administrator and payment of the aggregate Exercise Price for the Shares to be purchased, together with any applicable Tax-Related Items. This Option will be deemed exercised only when the Company receives: # notice of exercise (in such form as the Administrator may specify from time to time, including via electronic execution through an authorized third-party administrator) from the person entitled to exercise the Option; # full payment of the applicable Exercise Price in accordance with this Grant Agreement, and # payment of applicable Tax-Related Items, as determined by the Administrator. The Company will issue (or cause to be issued) such Shares promptly after the Option is exercised. No adjustment will be made for a dividend or other right for which the record date is prior to the date the Shares are issued, except in connection with a Capitalization Adjustment. Shares acquired pursuant to this Option may be issued as CDIs (except where a cashless exercise program is implemented in respect of the Option, in which case only Common Stock may be issued).

Exercise of Option. This Option is exercisable during its term in accordance with the Vesting Schedule contained in the Notice and the applicable provisions of the Grant Agreement. Grantee may exercise the vested portion of this Option only by following the option exercise procedures established by the Administrator and payment of the aggregate Exercise Price for the Shares to be purchased, together with any applicable Tax-Related Items. This Option will be deemed exercised only when the Company receives: # notice of exercise (in such form as the Administrator may specify from time to time, including via electronic execution through an authorized third-party administrator) from the person entitled to exercise the Option; # full payment of the applicable Exercise Price in accordance with this Grant Agreement, and # payment of applicable Tax-Related Items, as determined by the Administrator. The Company will issue (or cause to be issued) such Shares promptly after the Option is exercised subject to the requirements of Section 3. No adjustment will be made for a dividend or other right for which the record date is prior to the date the Shares are issued, except in connection with a Capitalization Adjustment. Shares acquired pursuant to this Option may be issued as CDIs and, unless the context otherwise requires, any references in this Grant Agreement to Shares include Shares that may be issued as CDIs.

Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to exercise his or her option to purchase ​ shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan and the Stock Option Agreement granted ​, ​ (the “Option Agreement”). The purchase price for the Shares shall be ​ per Share for a total purchase price of ​. The term “Shares” refers to the purchased Shares and all securities received in replacement of the Shares or as stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like, and all new, substituted or additional securities or other properties to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares.

Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to exercise his or her option to purchase ​ shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan and the Stock Option Agreement granted ​, ​ (the “Option Agreement”). The purchase price for the Shares shall be ​ per Share for a total purchase price of ​. The term “Shares” refers to the purchased Shares and all securities received in replacement of the Shares or as stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like, and all new, substituted or additional securities or other properties to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares.

Exercise of Option. An Option shall be exercised by # delivery to the Company of a written notice of exercise (on the form or in the manner specified by the Company for such notice) with respect to all or a specified number of shares of Common Stock subject to the Option, and # payment to the Company of the full amount of the Exercise Price in a manner permissible under Section 6.1(e) and the applicable Award Agreement.

Exercise of Option. Each employee who continues to be a participant in the Plan on the Exercise Date shall be deemed to have exercised his Option at the Option Price on such date and shall be deemed to have purchased the number of Shares that his accumulated payroll deductions on such date will pay for, but not in excess of the maximum numbers determined in the manner set forth above.

Exercise of Option. This Option shall be exercisable during its term in accordance with the Vesting/Exercise Schedule set out in the Notice and with the provisions of the Plan, including Section 6 thereof, and of this Agreement, including Section 5 hereof, as follows:

Exercise of Option. This Option shall be exercisable during its term in accordance with the Vesting/Exercise Schedule set out in the Notice and with the provisions of the Plan, including Section 6 thereof, and of this Agreement, including Section 5 hereof, as follows:

An Option will be deemed exercised when the Company receives: # notice of exercise (in accordance with the procedures that the Administrator may specify from time to time) from the person entitled to exercise the Option, and # full payment for the Shares with respect to which the Option is exercised (together with any amounts necessary to satisfy withholding obligations for Tax-Related Items). Full payment may consist of any consideration and method of payment authorized by the Administrator and permitted by the Award Agreement and the Plan. Shares issued upon exercise of an Option will be issued in the name of the Participant or, if requested by the Participant and approved by the Administrator, in the name of the Participant and his or her spouse. Until the Shares are issued (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a stockholder will exist with respect to the Shares subject to an Option, notwithstanding the exercise of the Option. The Company will issue (or cause to be issued) such Shares promptly after the Option is exercised. No adjustment will be made for a dividend or other right for which the record date is prior to the date the Shares are issued, except as provided in Section 14 of the Plan.

Exercise of Option. Effective as of today, ​, the undersigned (the “Grantee”) hereby elects to exercise the Grantee’s option to purchase shares of the Common Stock (the “Shares”) of Catalyst Biosciences, Inc. (the “Company”) under and pursuant to the Company’s 2018 Omnibus Incentive Plan, as amended from time to time (the “Plan”) and the Stock Option Award Agreement (the “Option Agreement”) and Notice of Stock Option Award (the “Notice”) dated ​, 20​ and this Exercise Notice (the “Exercise Notice”). Unless otherwise defined herein, the terms defined in the Plan shall have the same defined meanings in this Exercise Notice.