Form of Amendment to Share Option

This Amendment to that certain Share Option Grant Notice and Option Agreement (this “Amendment”) is entered into by and between [Optionholder] (“Optionholder”) and Biohaven Ltd. (the “Company”), effective as of [●], 2023 (“Amendment Effective Date”). Capitalized terms used but not defined herein will have the meanings given to them in the Option Agreement.

WHEREAS, the Company granted to Optionholder options (the “Options”) to purchase Common Shares of the Company pursuant to the Company’s 2022 Equity Incentive Plan (the “Plan”) and that certain Notice of Share Option Grant (the “Grant Notice”) and Share Option Agreement (the “Award Agreement”) and the exhibits and attachments attached thereto (together with the Grant Notice and Award Agreement, the “Option Agreement”);

WHEREAS, the Company and Optionholder desire to amend the “Exercise/Vesting Schedule” of the Grant Notice; and

WHEREAS, the Company and Optionholder desire to amend the Award Agreement to permit the Options to be exercised prior to vesting;

WHEREAS, the Board of Directors of the Company has approved this Amendment to amend the Option Agreement.

Now, Therefore, in consideration of the mutual promises, covenants and conditions hereinafter set forth, and for other good and valuable consideration, receipt and sufficiency of which are hereby acknowledged, the parties hereto mutually agree as follows:

1.Amendment to Exercise/Vesting Schedule: The penultimate sentence of “Exercise/Vesting Schedule” set forth in the Grant Notice is hereby amended and restated to read as follows:

Subject to Participant’s Continuous Service through each such vesting date; provided, however, that early exercise shall be permitted.

2.Amendment to Option Agreement (Early Exercise): The Award Agreement is hereby amended to add the following as a new Section 4 thereto:

4.    EXERCISE PRIOR TO VESTING (“EARLY EXERCISE”). Subject to the provisions of your option, you may elect at any time that is both (i) during the period of your Continuous Service and (ii) during the term of your option, to exercise all or part of the portion of your option, including, for the portion of your option that is a Nonstatutory Stock Option, the unvested portion of your option; provided, however, that:

(a)    a partial exercise of your option will be deemed to cover first Common Shares subject to the vested portion of your option and then Common Shares subject to the earliest vesting installment of the unvested portion of your option;

(b)    any Common Shares so purchased from installments that have not vested as of the date of exercise will be subject to the purchase option in favor of the Company as described in the Company’s form of Early Exercise Stock Purchase Agreement attached hereto as Attachment II;

(c)    you will enter into the Company’s form of Early Exercise Stock Purchase Agreement attached hereto as Attachment II with a vesting schedule that will result in the same vesting as if no early exercise had occurred; and

(d)    early exercise will not be permitted for any portion of your option that is an Incentive Stock Option.

3.Amendment to Option Agreement (Early Exercise Stock Purchase Agreement): The Award Agreement is hereby amended to add the form of Early Exercise Stock Purchase Agreement attached to this Amendment as Attachment II as a new Attachment II to the Award Agreement.

4.Entire Agreement; Counterparts.

WHEREAS, the Company granted to Purchaser options (the “Option”) to purchase Common Shares of the Company pursuant to the Company’s 2022 Equity Incentive Plan (the “Plan”) and that certain Notice of Share Option Grant (the “Grant Notice”) and Share Option Agreement (the “Award Agreement”) and the exhibits and attachments attached thereto (together with the Grant Notice and Award Agreement, the “Option Agreement”);

WHEREAS, Purchaser desires to exercise the Option on the terms and conditions contained herein; and

WHEREAS, Purchaser wishes to take advantage of the early exercise provision of Purchaser’s Option and therefore to enter into this Agreement.

NOW, THEREFORE, IT IS AGREED between the parties as follows:

1.Incorporation of Plan and Option by Reference. This Agreement is subject to all of the terms and conditions as set forth in the Plan and the Option. If there is a conflict between the terms of this Agreement and the terms of the Plan or the Option Agreement, the terms of the Plan or the Option Agreement shall control. Defined terms not explicitly defined in this Agreement but defined in the Plan shall have the same definitions as in the Plan. Defined terms not explicitly defined in this Agreement or the Plan but defined in the Option Agreement shall have the same definitions as in the Option Agreement.

2.Purchase and Sale of Common Shares.

(a)Agreement to Purchase and Sell Common Shares. Purchaser hereby agrees to purchase from the Company, and the Company hereby agrees to sell to Purchaser, an aggregate of ( ) Common Shares at $ per Common Share, for an aggregate purchase price of $         , payable as follows:

Purchaser shall also pay to the Company $         in cash or by check, bank draft or money order payable to the Company to cover any applicable withholding taxes which may be incurred upon exercise of the Option in accordance with this Agreement.

(b)Closing. The closing hereunder, including payment for and delivery of the Common Shares, shall occur at the offices of the Company immediately following the execution of this Agreement, or at such other time and place as the parties may mutually agree; provided, however, that if stockholder approval of the Plan is required before the Option may be exercised, then the Option may not be exercised, and the closing shall be delayed, until such stockholder approval is obtained. If such stockholder approval is not obtained within the time limit specified in the Plan, then this Agreement shall be null and void.

3.Unvested Common Share Repurchase Option.

(a)Repurchase Option. In the event Purchaser’s Continuous Service terminates, then the Company shall have an irrevocable option (the “Repurchase Option”) for a period of ninety (90) days after said termination, or such longer period as may be agreed to by the Company and Purchaser, to repurchase from Purchaser or Purchaser’s personal representative, as the case may be, those shares that Purchaser received pursuant to the exercise of the Option that have not as yet vested as of such termination date in accordance with the Vesting Schedule indicated on Purchaser’s Grant Notice (the “Unvested Shares”).

(b)Share Repurchase Price. The Company may repurchase all or any of the Unvested Shares at the lower of (i) the Fair Market Value of the such shares (as determined under the Plan) on the date of repurchase, or (ii) the price equal to Purchaser’s Exercise Price for such shares as indicated on Purchaser’s Grant Notice.

(c)Exercise of Repurchase Option. The Repurchase Option shall be exercised by written notice signed by such person as designated by the Company, and delivered or mailed as provided herein. Such notice shall identify the number of Common Shares to be purchased and shall notify Purchaser of the time, place and date for settlement of such purchase, which shall be scheduled by the Company within the term of the Repurchase Option set forth above. The Company shall be entitled to pay for any Common Shares purchased pursuant to its Repurchase Option at the Company’s option in cash or by offset against any indebtedness owing to the Company by Purchaser, or by a combination of both. Upon delivery of such notice and payment of the purchase price in any of the ways described above, the Company shall become the legal and beneficial owner of the Common Shares being repurchased and all rights and interest therein or related thereto, and the Company shall have the right to transfer to its own name the Common Shares being repurchased by the Company, without further action by Purchaser.

4.Capitalization Adjustments to Common Shares. In the event of a Capitalization Adjustment, then any and all new, substituted or additional securities or other property to which Purchaser is entitled by reason of Purchaser’s ownership of Common Shares shall be immediately subject to the Repurchase Option and be included in the word “Common Shares” for all purposes of the Repurchase Option with the same force and effect as the Common Shares presently subject to the Repurchase Option, but only to the extent the Common Shares are, at the time, covered by such Repurchase Option. While the total Option Price shall remain the same after each such event, the Option Price per share of Common Shares upon exercise of the Repurchase Option shall be appropriately adjusted.

5.Corporate Transactions. In the event of a Corporate Transaction, then the Repurchase Option may be assigned by the Company to the successor of the Company (or such successor’s parent company), if any, in connection with such Corporate Transaction. To the extent the Repurchase Option remains in effect following such Corporate Shares, it shall apply to the new capital stock or other property received in exchange for the Common Shares in consummation of the Corporate Transaction, but only to the extent the Common Shares was at the time covered by such right. Appropriate adjustments shall be made to the price per share payable upon exercise of the Repurchase Option to reflect the Corporate Transaction upon the Company’s capital structure; provided, however, that the aggregate price payable upon exercise of the Repurchase Option shall remain the same.

6.Escrow of Unvested Common Shares. As security for Purchaser’s faithful performance of the terms of this Agreement and to insure the availability for delivery of Purchaser’s Common Shares upon exercise of the Repurchase Option herein provided for, Purchaser agrees, at the closing hereunder, to deliver to and deposit with [____________] (“Escrow Agent”), as Escrow Agent in this transaction, three (3) stock assignments duly endorsed (with date and number of shares blank) in the form attached hereto as Exhibit A, together with a certificate or certificates evidencing all of the Common Shares subject to the Repurchase Option; said documents are to be held by the Escrow Agent and delivered by said Escrow Agent pursuant to the Joint Escrow Instructions of the Company and Purchaser set forth in Exhibit B, attached hereto and incorporated by this reference, which instructions also shall be delivered to the Escrow Agent at the closing hereunder.

7.Rights of Purchaser. Subject to the provisions of the Option, Purchaser shall exercise all rights and privileges of a stockholder of the Company with respect to the shares deposited in escrow. Purchaser shall be deemed to be the holder of the shares for purposes of receiving any dividends that may be paid with respect to such shares and for purposes of exercising any voting rights relating to such shares, even if some or all of such shares have not yet vested and been released from the Company’s Repurchase Option.

8.Limitations on Transfer. In addition to any other limitation on transfer created by applicable securities laws, Purchaser shall not sell, assign, hypothecate, donate, encumber or otherwise dispose of any interest in the Common Shares while the Common Shares is subject to the Repurchase Option. After any Common Shares has been released from the Repurchase Option, Purchaser shall not sell, assign, hypothecate, donate, encumber or otherwise dispose of any interest in the Common Shares except in compliance with the provisions herein and applicable securities laws. Furthermore, the Common Shares shall be subject to any right of first refusal in favor of the Company or its assignees that may be contained in Purchaser’s Option Agreement.

9.Restrictive Legends. All certificates representing the Common Shares shall have endorsed thereon legends in substantially the following forms (in addition to any other legend which may be required by other agreements between the parties hereto):

10.Section 83(b) Election. Purchaser acknowledges and agrees that, no later than thirty (30) days of the date of purchase, Purchaser shall file an election under Section 83(b) of the Code (an “83(b) Election”) with the Internal Revenue Service and shall promptly send a copy of such 83(b) Election to the Company. Forms of 83(b) Election are attached hereto as Exhibit C for reference.

11.Refusal to Transfer. The Company shall not be required (a) to transfer on its books any Common Shares of the Company which shall have been transferred in violation of any of the provisions set forth in this Agreement, or (b) to treat as owner of such shares or to accord the right to vote as such owner or to pay dividends to any transferee to whom such shares shall have been so transferred.

12.No Employment Rights. This Agreement is not an employment contract and nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company or its Affiliates to terminate Purchaser’s employment for any reason at any time, with or without cause and with or without notice.

13.Miscellaneous.

(a)Notices. Any notices required or permitted hereunder will be given in writing (including electronically) and will be deemed effectively given upon receipt or, in the case of notices delivered by mail by the Company to Purchaser, five (5) days after deposit in the United States mail, postage prepaid, addressed to Purchaser at the last address you provided to the Company. The Company may, in its sole discretion, decide to deliver any documents notices required or permitted hereunder by electronic means. By signing this Agreement, Purchaser consents to receive such documents by electronic delivery and to participate in the Plan.

(b)Successors and Assigns. This Agreement shall inure to the benefit of the successors and assigns of the Company and, subject to the restrictions on transfer herein set forth, be binding upon Purchaser, Purchaser’s successors, and assigns. The Company may assign the Repurchase Option hereunder at any time or from time to time, in whole or in part.

(c)Specific Performance. It is the intention of the parties that the Company, upon exercise of the Repurchase Option and payment for the shares repurchased, pursuant to the terms of this Agreement, shall be entitled to receive the Common Shares, in specie, in order to have such Common Shares available for future issuance without dilution of the holdings of other stockholders. Furthermore, it is expressly agreed between the parties that money damages are inadequate to compensate the Company for the Common Shares and that the Company shall, upon proper exercise of the Repurchase Option, be entitled to specific enforcement of its rights to purchase and receive said Common Shares.

(d)Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of Delaware.

(e)Further Execution. The parties agree to take all such further action(s) as may reasonably be necessary to carry out and consummate this Agreement as soon as practicable, and to take whatever steps may be necessary to obtain any governmental approval in connection with or otherwise qualify the issuance of the securities that are the subject of this Agreement.

(f)Entire Agreement; Amendment. This Agreement constitutes the entire agreement between the parties with respect to the subject matter hereof and supersedes and merges all prior agreements or understandings, whether written or oral. This Agreement may not be amended, modified or revoked, in whole or in part, except by an agreement in writing signed by each of the parties hereto.

(g)Severability. If one or more provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms.

(h)Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original and all of which together shall constitute one instrument. This Agreement may also be executed and delivered by facsimile signature, PDF or any electronic signature complying with the U.S. federal ESIGN Act of 2000 (e.g., www.docusign.com).

For Value Received,     hereby sells, assigns and transfers unto Biohaven Ltd., a BVI business company (the “Company”), pursuant to the Repurchase Option under that certain Early Exercise Stock Purchase Agreement, dated         by and between the undersigned and the Company (the “Agreement”),      (    ) Common Shares of the Company standing in the undersigned’s name on the books of the Company represented by Certificate No(s).      and does hereby irrevocably constitute and appoint the Company’s Secretary attorney-in-fact to transfer said Common Shares on the books of the Company with full power of substitution in the premises. This Assignment may be used only in accordance with and subject to the terms and conditions of the Agreement, in connection with the repurchase of Common Shares issued to the undersigned pursuant to the Agreement, and only to the extent that such shares remain subject to the Company’s Repurchase Option under the Agreement.

Dated:     

As Escrow Agent for both Biohaven Ltd., a BVI business company (the “Company”), and the undersigned purchaser of Common Shares of the Company (“Purchaser”), you are hereby authorized and directed to hold the documents delivered to you pursuant to the terms of that certain Early Exercise Stock Purchase Agreement (“Agreement”), dated _________ to which a copy of these Joint Escrow Instructions is attached as Exhibit B, in accordance with the following instructions:

1.In the event the Company or an assignee shall elect to exercise the Repurchase Option set forth in the Agreement, the Company or its assignee will give to Purchaser and you a written notice specifying the number of Common Shares to be purchased, the purchase price, and the time for a closing hereunder at the principal office of the Company. Purchaser and the Company hereby irrevocably authorize and direct you to close the transaction contemplated by such notice in accordance with the terms of said notice.

2.At the closing you are directed (a) to date any stock assignments necessary for the transfer in question, (b) to fill in the number of shares being transferred, and (c) to deliver same, together with the certificate evidencing the Common Shares to be transferred, to the Company against the simultaneous delivery to you of the purchase price (which may include suitable acknowledgment of cancellation of indebtedness) of the number of Common Shares being purchased pursuant to the exercise of the Repurchase Option.

3.Purchaser irrevocably authorizes the Company to deposit with you any certificates evidencing Common Shares to be held by you hereunder and any additions and substitutions to said shares as specified in the Agreement. Purchaser does hereby irrevocably constitute and appoint you as the Purchaser’s attorney-in-fact and agent for the term of this escrow to execute with respect to such securities and other property all documents of assignment and/or transfer and all stock certificates necessary or appropriate to make all securities negotiable and complete any transaction herein contemplated, including but not limited to any appropriate filing with state or government officials or bank officials. Subject to the provisions of this paragraph 3, Purchaser shall exercise all rights and privileges of a stockholder of the Company while the stock is held by you.

4.This escrow shall terminate and the shares of stock held hereunder shall be released in full upon the expiration or exercise in full of the Repurchase Option, whichever occurs first.

5.If at the time of termination of this escrow you should have in your possession any documents, securities, or other property belonging to Purchaser, you shall deliver all of same to Purchaser and shall be discharged of all further obligations hereunder; provided, however, that if at the time of termination of this escrow you are advised by the Company that the property subject to this escrow is the subject of a pledge or other security agreement, you shall deliver all such property to the pledgeholder or other person designated by the Company.

6.Except as otherwise provided in these Joint Escrow Instructions, your duties hereunder may be altered, amended, modified or revoked only by a writing signed by all of the parties hereto.

7.You shall be obligated only for the performance of such duties as are specifically set forth herein and may rely and shall be protected in relying or refraining from acting on any instrument reasonably believed by you to be genuine and to have been signed or presented by the proper party or parties or their assignees. You shall not be personally liable for any act you may do or omit to do hereunder as Escrow Agent or as attorney-in-fact for Purchaser while acting in good faith and any act done or omitted by you pursuant to the advice of your own attorneys shall be conclusive evidence of such good faith.

8.You are hereby expressly authorized to disregard any and all warnings given by any of the parties hereto or by any other person or corporation, excepting only orders or process of courts of law, and are hereby expressly authorized to comply with and obey orders, judgments or decrees of any court. In case you

obey or comply with any such order, judgment or decree of any court, you shall not be liable to any of the parties hereto or to any other person, firm or corporation by reason of such compliance, notwithstanding any such order, judgment or decree being subsequently reversed, modified, annulled, set aside, vacated or found to have been entered without jurisdiction.

9.You shall not be liable in any respect on account of the identity, authority or rights of the parties executing or delivering or purporting to execute or deliver the Agreement or any documents or papers deposited or called for hereunder.

10.You shall not be liable for the outlawing of any rights under any statute of limitations with respect to these Joint Escrow Instructions or any documents deposited with you.

11.Your responsibilities as Escrow Agent hereunder shall terminate if you shall cease to be Secretary of the Company or if you shall resign by written notice to the Company party. In the event of any such termination, the Secretary of the Corporation shall automatically become the successor Escrow Agent unless the Company shall appoint another successor Escrow Agent, and Purchaser hereby confirms the appointment of such successor as Purchaser’s attorney-in-fact and agent to the full extent of your appointment.

12.If you reasonably require other or further instruments in connection with these Joint Escrow Instructions or obligations in respect hereto, the necessary parties hereto shall join in furnishing such instruments.

13.It is understood and agreed that should any dispute arise with respect to the delivery and/or ownership or right of possession of the securities, you are authorized and directed to retain in your possession without liability to anyone all or any part of said securities until such dispute shall have been settled either by mutual written agreement of the parties concerned or by a final order, decree or judgment of a court of competent jurisdiction after the time for appeal has expired and no appeal has been perfected, but you shall be under no duty whatsoever to institute or defend any such proceedings.

14.Any notice required or permitted hereunder shall be given in writing and shall be deemed effectively given upon personal delivery, including delivery by express courier or five days after deposit in the United States Post Office, by registered or certified mail with postage and fees prepaid, addressed to each of the other parties hereunto entitled at the following addresses, or at such other addresses as a party may designate by ten days’ advance written notice to each of the other parties hereto:

15.By signing these Joint Escrow Instructions you become a party hereto only for the purpose of said Joint Escrow Instructions; you do not become a party to the Agreement.

16.You shall be entitled to employ such legal counsel and other experts as you may deem necessary properly to advise you in connection with your obligations hereunder. You may rely upon the advice of such counsel, and may pay such counsel reasonable compensation therefor. The Company shall be responsible for all fees generated by such legal counsel in connection with your obligations hereunder.

17.This instrument shall be binding upon and inure to the benefit of the parties hereto and their respective successors and permitted assigns. It is understood and agreed that references to “you” or “your” herein

refer to the original Escrow Agent and to any and all successor Escrow Agents. It is understood and agreed that the Company may at any time or from time to time assign its rights under the Agreement and these Joint Escrow Instructions in whole or in part.

18.This Agreement shall be governed by and interpreted and determined in accordance with the laws of the State of Delaware.

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended, to include in gross income as compensation for services the excess (if any) of the fair market value of the shares described below over the amount paid for those shares. The following information is supplied in accordance with Treasury Regulation § 1.83-2:

4.The property is subject to the following restrictions: The shares are subject to repurchase at less than their fair market value if the undersigned does not continue to provide services for the Company for a designated period of time. The right of repurchase lapses over a specified vesting period.

The undersigned taxpayer will file this election with the Internal Revenue Service office with which taxpayer files his or her annual income tax return not later than 30 days after the date of transfer of the property. A copy of the

election also will be furnished to the person for whom the services were performed and the transferee of the property, if any. Additionally, the undersigned will include a copy of the election with his or her income tax return for the taxable year in which the property is transferred. The undersigned is the person performing the services in connection with which the property was transferred.

Attached is a form of election under Section 83(b) of the Internal Revenue Code and an accompanying IRS cover letter. Please fill in your social security number and sign the election and cover letter, then proceed as follows:

Note: An additional copy of the completed election form must be delivered to the transferee (recipient) of the property if the service provider and the transferee are not the same person.