CRISPR Therapeutics AG

Appendix A

AMENDMENT NO. 5 TO THE

2018 STOCK OPTION AND INCENTIVE PLAN

The CRISPR Therapeutics AG 2018 Stock Option and Incentive Plan (the “Plan”) is hereby amended as follows:

Section 3(a) of the Plan is hereby amended by deleting it and replacing it with the following:

Stock Issuable. The maximum number of shares of Stock reserved and available for issuance under the Plan shall be 17,400,000 shares, plus the number of shares available for issuance under the Company’s Amended and Restated 2016 Stock Option and Grant Plan (the “2016 Plan”) as of immediately prior to the Effective Date, subject to adjustment as provided in Section 3. For purposes of this limitation, the shares of Stock underlying any Awards under the Plan or any shares of Stock underlying any awards under the Company’s 2015 Stock Option and Grant Plan or the 2016 Plan that are forfeited, canceled, held back upon exercise of an Option or settlement of an Award to cover the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of Stock or otherwise terminated (other than by exercise) shall be added back to the shares of Stock available for issuance under the Plan. In the event the Company repurchases shares of Stock on the open market, such shares shall not be added to the shares of Stock available for issuance under the Plan. Subject to such overall limitations, shares of Stock may be issued up to such maximum number pursuant to any type or types of Award; provided, however, that no more than 28,405,365 shares of the Stock may be issued in the form of Incentive Stock Options. The shares available for issuance under the Plan may be authorized but unissued shares of Stock or shares of Stock reacquired by the Company.

ADOPTED BY BOARD OF DIRECTORS: March 14, 2024

ADOPTED BY SHAREHOLDERS:

Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) [PLEASE SIGN WITHIN BOX] Date TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: CRISPR THERAPEUTICS AG BAARERSTRASSE 14 6300 ZUG SWITZERLAND CRISPR Therapeutics AG THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. 6.c Binding vote on maximum non-performance-related compensation for members of the Executive Committee from July 1, 2024 to June 30, 2025. 6.d Binding vote on maximum variable compensation for members of the Executive Committee for the current year ending December 31, 2024. 6.e Binding vote on maximum equity for members of the Executive Committee from the 2024 Annual General Meeting to the 2025 annual general meeting of shareholders. 6.f Non-binding advisory vote on the 2023 Compensation Report. 7. Non-binding advisory vote on the compensation paid to the Company’s named executive officers under U.S. securities law requirements. 8. Approval of an increase of the conditional share capital for employee equity plans. 9. Approval of an amendment to the CRISPR Therapeutics AG 2018 Stock Option and Incentive Plan. 10. Approval of amendments to the Articles of Association to facilitate the use of equity compensation and pension benefits programs consistent with current market practices. 11. Approval of an increase and certain adjustments to the Company's capital band. 12. Re-election of the independent voting rights representative. 13. Re-election of the auditors. 14. Transact any other business that may properly come before the 2024 Annual General Meeting or any adjournment or postponement thereof. Authorized Signatures - Must be completed for your instructions to be executed. Please sign exactly as your name(s) appear(s) on your account. If held in joint tenancy, all persons should sign. Trustees, administrators, etc., should include title and authority. Corporations should provide full name of corporation and title of authorized officer signing the Proxy/Vote Form. For Against Abstain For Against Abstain THE BOARD OF DIRECTORS RECOMMENDS A VOTE: FOR ON PROPOSALS 1, 2, 3, 4.a, 4.b, 4.c, 4.d, 4.e, 4.f, 4.g, 4.h, 4.i, 4.j, 5.a, 5.b, 5.c, 5.d, 6.a, 6.b, 6.c, 6.d, 6.e, 6.f, 7, 8, 9, 10, 11, 12, AND 13. 6. Approval of the compensation for the Board of Directors and the Executive Committee and non-binding advisory vote on the 2023 Compensation Report. 6.a Binding vote on maximum non-performance-related compensation for members of the Board of Directors from the 2024 Annual General Meeting to the 2025 annual general meeting of shareholders. 6.b Binding vote on maximum equity for members of the Board of Directors from the 2024 Annual General Meeting to the 2025 annual general meeting of shareholders. PROPOSALS: 1. Approval of the Swiss management report, the consolidated financial statements and the statutory financial statements of the Company for the year ended December 31, 2023. 2. Approval of the appropriation of financial results. 3. Discharge of the members of the Board of Directors and the Executive Committee. 4. Election or re-election of the members to the Board of Directors and the Chairman. 5. Re-election of the members of the Compensation Committee. 5.a Re-election of Ali Behbahani, M.D. 5.b Re-election of H. Edward Fleming, Jr., M.D. 5.c Re-election of Simeon J. George, M.D. 5.d Re-election of John T. Greene 4.a Re-election of Samarth Kulkarni, Ph.D., as member and election as Chairman 4.b Re-election of Ali Behbahani, M.D. 4.c Re-election of Maria Fardis, Ph.D. 4.d Re-election of H. Edward Fleming, Jr., M.D. 4.e Re-election of Simeon J. George, M.D. 4.f Re-election of John T. Greene 4.g Re-election of Katherine A. High, M.D. 4.i Election of Sandesh Mahatme, LL.M. 4.h Re-election of Douglas A. Treco, Ph.D. 4.j Election of Christian Rommel, Ph.D. V43192-P04468 VOTE BY INTERNET - www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information up until 6:00 p.m. Central European Summer Time (12:00 p.m. Eastern Daylight Time) on May 29, 2024. Have your proxy card in hand when you access the website and follow the instructions to obtain your records and to create an electronic voting instruction form. ELECTRONIC DELIVERY OF FUTURE PROXY MATERIALS If you would like to reduce the costs incurred by our company in mailing proxy materials, you can consent to receiving all future proxy statements, proxy cards and annual reports electronically via e-mail or the Internet. To sign up for electronic delivery, please follow the instructions above to vote using the Internet and, when prompted, indicate that you agree to receive or access proxy materials electronically in future years. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. SCAN TO VIEW MATERIALS & VOTE

The undersigned hereby appoints Marius Meier, as a proxy of the undersigned, or the Named Proxy, with full power of substitution, to vote all of the common shares, or the Shares, of CRISPR Therapeutics AG that the undersigned may be entitled to vote at the 2024 Annual General Meeting of Shareholders of CRISPR Therapeutics AG, or the Company, to be held as a physical meeting at the offices of Walder Wyss Ltd., Seefeldstrasse 123, 8008 Zurich, Switzerland at 8:00 a.m. Central European Summer Time (2:00 a.m. Eastern Daylight Time) on Thursday, May 30, 2024, and at any and all postponements and adjournments thereof, with all powers that the undersigned would possess if personally present, upon and in respect of the matters indicated on the reverse side, in accordance with the following instructions, with discretionary authority as to any and all other matters that may properly come before the meeting and at any and all postponements and adjournments thereof. If you sign the proxy without otherwise indicating a vote on the proposals, this proxy will be voted “FOR” each of the nominees and the proposals listed on the reverse side. As to any other matter that may properly come before the meeting and all postponements, continuances and adjournments thereof, the Shares will be voted by the proxies in accordance with their judgment. If specific instructions are indicated, this proxy, when properly executed, will be voted in the manner directed herein. The Company's Board of Directors recommends that shareholders vote “FOR” Proposals 1-13. If you have any questions about the 2024 Annual General Meeting including directions on how to attend in person, please contact AJ Silver, the Company's Vice President, Corporate Finance. He may be contacted before May 29, 2024 at 105 West First Street, South Boston, MA 02127, telephone: +1 617-315-4600. Alternatively, any questions may be directed by e-mail to: secretary@crisprtx.com. You are encouraged to specify your choice by marking the appropriate box (SEE REVERSE SIDE) but you need not mark any box if you wish to vote in accordance with the Board of Directors’ recommendation. The Named Proxy cannot vote your shares unless you sign (on the reverse side) and return this card. CRISPR THERAPEUTICS AG 2024 Annual General Meeting of Shareholders For Shareholders of Record on April 8, 2024 Thursday, May 30, 2024 8:00 a.m. Central European Summer Time (2:00 a.m. Eastern Daylight Time) Walder Wyss Ltd., Seefeldstrasse 123, 8008 Zurich, Switzerland This proxy is being solicited on behalf of the Board of Directors V43193-P04468 PLEASE BE SURE TO SIGN AND DATE THIS PROXY CARD AND MARK ON THE REVERSE SIDE Important Notice Regarding the Availability of Proxy Materials for the 2024 Annual General Meeting of Shareholders: The Notice and Proxy Statement, 10K Wrap and Swiss Statutory Financial Statements and Audit Reports are available at www.proxyvote.com.