2016 Stock Incentive Plan, as amended, and forms of award agreements

Exhibit 10.2

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

As Amended and Restated on September 2, 2020

1. PURPOSE. The purpose of this Plan is to provide incentives to attract, retain and motivate eligible persons whose present and potential contributions are important to the success of the Company, its Parent and Subsidiaries by offering eligible persons an opportunity to participate in the Company’s future performance through the grant of Awards covering Shares. Capitalized terms not defined in the text are defined in Section 14 hereof. Although this Plan is intended to be a written compensatory benefit plan within the meaning of Rule 701, grants may be made pursuant to this Plan that do not qualify for exemption under Rule 701.

2. SHARES SUBJECT TO THE PLAN.

2.1 Number of Shares Available. Subject to Sections 2.2 and 11 hereof, the total number of Shares reserved and available for grant and issuance pursuant to this Plan will be 10,420,296 Shares plus (a) any authorized shares not issued or subject to outstanding grants under the Company’s 2016 Stock Incentive Plan (the “Prior Plan”) on the Effective Date (as defined in Section 13.1 hereof); (b) shares that are subject to issuance under the Prior Plan but cease to be subject to an award for any reason other than exercise of an option after the Effective Date; and (c) shares that were issued under the Prior Plan which are repurchased by the Company or which are forfeited or used to pay withholding obligations or pay the exercise price of an Option. Subject to Sections 2.2 and 11 hereof, (A) in the event that Shares previously issued under the Plan are reacquired by the Company pursuant to a forfeiture provision, right of first refusal, or repurchase by the Company, such Shares shall be added to the number of Shares then available for issuance under the Plan; (B) in the event that Shares that otherwise would have been issuable under the Plan are withheld by the Company in payment of the Purchase Price, Exercise Price or withholding obligations, such Shares shall remain available for issuance under the Plan; and (C) in the event that an outstanding Option, Restricted Stock Unit or SAR for any reason expires or is cancelled, forfeited or terminated, the Shares allocable to the unexercised or unsettled portion of such Option, Restricted Stock Unit or SAR, as applicable, shall remain available for issuance under the Plan. To the extent an Award is settled in cash, the cash settlement shall not reduce the number of Shares remaining available for issuance under the Plan. At all times the Company will reserve and keep available a sufficient number of Shares as will be required to satisfy the requirements of all Awards granted and outstanding under this Plan. In no event shall the total number of Shares issued (counting each reissuance of a Share that was previously issued and then reacquired by the Company pursuant to a forfeiture provision, right of first refusal, or repurchase by the Company as a separate issuance) under the Plan upon exercise of ISOs (as defined in Section 4 hereof) exceed 20,840,592 Shares (adjusted in proportion to any adjustments under Section 2.2 hereof) over the term of the Plan.

2.2 Adjustment of Shares. In the event that the number of outstanding shares of the Company’s Common Stock is changed by a stock dividend, recapitalization, stock split, reverse stock split, subdivision, combination, reclassification or other change in the capital structure of the Company affecting Shares without consideration, then in order to prevent diminution or enlargement of the benefits or potential benefits intended to be made available under the Plan (a) the number and class of Shares reserved for issuance under this Plan, (b) the Exercise Prices of and number and class of Shares subject to outstanding Options and SARs, and (c) the Purchase Prices of and/or number and class of Shares subject to other outstanding Awards will (to the extent appropriate) be proportionately adjusted, subject to any required action by the Board or the stockholders of the Company and compliance with applicable securities or other laws; provided, however, that fractions of a Share will not be issued but will either be paid in cash at the Fair Market Value of such fraction of a Share or will be rounded down to the nearest whole Share, as determined by the Committee.

1

3. PLAN FOR BENEFIT OF SERVICE PROVIDERS.

3.1 Eligibility. The Committee will have the authority to select persons to receive Awards. ISOs may be granted only to employees (including officers and directors who are also employees) of the Company or of a Parent or Subsidiary of the Company. NQSOs (as defined in Section 4 hereof) and all other types of Awards may be granted to employees, officers, directors and consultants of the Company or any Parent or Subsidiary of the Company; provided such consultants render bona fide services not in connection with the offer and sale of securities in a capital-raising transaction when Rule 701 is to apply to the Award granted for such services. A person may be granted more than one Award under this Plan.

3.2 No Obligation to Employ. Nothing in this Plan or any Award granted under this Plan will confer or be deemed to confer on any Participant any right to continue in the employ of, or to continue any other relationship with, the Company or any Subsidiary or Parent of the Company or limit in any way the right of the Company or any Subsidiary or Parent of the Company to terminate Participant’s employment or other relationship at any time, with or without Cause.

4. OPTIONS. The Committee may grant Options to eligible persons described in Section 3 hereof and will determine whether such Options will be Incentive Stock Options within the meaning of the Code (“ISOs”) or Nonqualified Stock Options (“NQSOs”), the number of Shares subject to the Option, the Exercise Price of the Option, the period during which the Option may be exercised, and all other terms and conditions of the Option, subject to the following.

4.1 Form of Option Grant. Each Option granted under this Plan will be evidenced by an Award Agreement which will expressly identify the Option as an ISO or an NQSO (“Stock Option Agreement”), and will be in such form and contain such provisions (which may be electronic or written and need not be the same for each Participant) as the Committee may from time to time approve, and which will comply with and be subject to the terms and conditions of this Plan.

4.2 Date of Grant. The date of grant of an Option will be the date on which the Committee makes the determination to grant such Option, unless a later date is otherwise specified by the Committee. The Stock Option Agreement and a copy of this Plan will be delivered to the Participant within a reasonable time after the granting of the Option.

4.3 Exercise Period. Options may be exercisable within the time or upon the events determined by the Committee in the Award Agreement and may be awarded as immediately exercisable but subject to repurchase pursuant to Section 10 hereof or may be exercisable within the times or upon the events determined by the Committee as set forth in the Stock Option Agreement governing such Option; provided, however, that (a) no Option will be exercisable after the expiration of ten (10) years from the date the Option is granted; and (b) no ISO granted to a person who directly or by attribution owns more than ten percent (10%) of the total combined voting power of all classes of stock of the Company or of any Subsidiary or Parent of the Company (“Ten Percent Stockholder”) will be exercisable after the expiration of five (5) years from the date the ISO is granted; but in no event shall an Option granted to an employee who is a non-exempt employee for purposes of overtime pay under the U.S. Fair Labor Standards Act of 1938 be exercisable earlier than six (6) months after its date of grant. The Committee also may provide for Options to become exercisable at one time or from time to time, periodically or otherwise, in such number of Shares or percentage of Shares as the Committee determines.

4.4 Exercise Price. The Exercise Price of an Option will be determined by the Committee when the Option is granted and shall not be less than the Fair Market Value per Share on the date of grant unless expressly determined in writing by the Committee on the Options’s date of grant; provided that the Exercise Price of an ISO granted to a Ten Percent Stockholder will not be less than one hundred ten percent (110%) of the Fair Market Value of the Shares on the date of grant. Payment for the Shares purchased must be made in accordance with Section 8 hereof.

2

4.5 Method of Exercise. Options may be exercised only by delivery to the Company of a stock option exercise agreement (accepted via written, electronic or other means) (the “Exercise Agreement”) in a form approved by the Committee (which need not be the same for each Participant). The Exercise Agreement will state (a) the number of Shares being purchased, (b) the restrictions imposed on the Shares purchased under such Exercise Agreement, if any, and (c) such representations and agreements regarding Participant’s investment intent and access to information and other matters, if any, as may be required or desirable by the Company to comply with applicable securities or other laws. Each Participant’s Exercise Agreement may be modified by (i) agreement of Participant and the Company or (ii) substitution by the Company, upon becoming a public company, in order to add the payment terms set forth in Section 8.1 that apply to a public company and such other terms as shall be necessary or advisable in order to exercise a public company option. Upon exercise of an Option, Participant shall execute and deliver to the Company the Exercise Agreement then in effect, together with payment in full of the Exercise Price for the number of Shares being purchased and satisfaction of any applicable Tax-Related Obligations (as defined in Section 8.2 hereof). 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 2.2 of the Plan. Exercising an Option in any manner will decrease the number of Shares thereafter available, both for purposes of the Plan and for sale under the Option, by the number of Shares as to which the Option is exercised.

4.6 Termination. Subject to earlier termination pursuant to Sections 11 and 13 hereof and subject to any longer exercise periods set forth in the Stock Option Agreement, exercise of an Option will always be subject to the following terms and conditions.

4.6.1 Other than Death or Disability or for Cause. If the Participant is Terminated for any reason other than death, Disability or for Cause, then the Participant may exercise such Participant’s Options only to the extent that such Options are exercisable as to Vested Shares upon the Termination Date, except as otherwise determined by the Committee or required by applicable law. Such Options must be exercised by the Participant, if at all, as to all or some of the Vested Shares calculated as of the Termination Date or such other date determined by the Committee, within three (3) months after the Termination Date (or within such shorter time period, not less than thirty (30) days, or within such longer time period after the Termination Date as may be determined by the Committee or required by applicable law, with any exercise beyond three (3) months after the date Participant ceases to be an employee deemed to be an NQSO) but, in any event, no later than the expiration date of the Options.

4.6.2 Death or Disability. If the Participant is Terminated because of Participant’s death or Disability (or the Participant dies within three (3) months after a Termination other than for Cause), then Participant’s Options may be exercised only to the extent that such Options are exercisable as to Vested Shares on the Termination Date, except as otherwise determined by the Committee or required by applicable law. Such Options must be exercised by Participant (or Participant’s legal representative or authorized assignee), if at all, as to all or some of the Vested Shares calculated as of the Termination Date or such other date determined by the Committee, within twelve (12) months after the Termination Date (or within such shorter time period, not less than six (6) months, or within such longer time period, after the Termination Date as may be determined by the Committee or required by applicable law, with any exercise beyond (a) three (3) months after the date Participant ceases to be an employee when the Termination is for any reason other than the Participant’s death or disability, within the meaning of Section 22(e)(3) of the Code, or (b) twelve (12) months after the date Participant ceases to be an employee when the Termination is for Participant’s disability, within the meaning of Section 22(e)(3) of the Code, deemed to be an NQSO) but in any event no later than the expiration date of the Options.

4.6.3 For Cause. If the Participant is Terminated for Cause, the Participant may exercise such Participant’s Options, but not to an extent greater than such Options are exercisable as to Vested Shares upon the Termination Date and Participant’s Options shall expire on such Participant’s Termination Date, or at such later time and on such conditions as are determined by the Committee.

3

4.7 Limitations on Exercise. The Committee may specify a reasonable minimum number of Shares that may be purchased on any exercise of an Option, provided that such minimum number will not prevent Participant from exercising the Option for the full number of Shares for which it is then exercisable.

4.8 Limitations on ISOs. The aggregate Fair Market Value (determined as of the date of grant) of Shares with respect to which ISOs are exercisable for the first time by a Participant during any calendar year (under this Plan or under any other incentive stock option plan of the Company or any Parent or Subsidiary of the Company) will not exceed One Hundred Thousand Dollars ($100,000). If the Fair Market Value of Shares on the date of grant with respect to which ISOs are exercisable for the first time by a Participant during any calendar year exceeds One Hundred Thousand Dollars ($100,000), then the Options for the first One Hundred Thousand Dollars ($100,000) worth of Shares to become exercisable in such calendar year will be ISOs and the Options for the amount in excess of One Hundred Thousand Dollars ($100,000) that become exercisable in that calendar year will be NQSOs. In the event that the Code or the regulations promulgated thereunder are amended after the Effective Date (as defined in Section 13.1 hereof) to provide for a different limit on the Fair Market Value of Shares permitted to be subject to ISOs, then such different limit will be automatically incorporated herein and will apply to any Options granted after the effective date of such amendment.

4.9 Modification, Extension or Renewal. The Committee may modify, extend or renew outstanding Options and authorize the grant of new Options in substitution therefor, provided that any such action may not, without the written consent of a Participant, impair any of such Participant’s rights under any Option previously granted, unless for the purpose of complying with applicable laws and regulations. Any outstanding ISO that is modified, extended, renewed or otherwise altered will be treated in accordance with Section 424(h) of the Code. Subject to Section 4.10 hereof, the Committee may reduce the Exercise Price of outstanding Options without the consent of Participants by a written notice to them; provided, however, that the Exercise Price may not be reduced below the minimum Exercise Price that would be permitted under Section 4.4 hereof for Options granted on the date the action is taken to reduce the Exercise Price.

4.10 No Disqualification. Notwithstanding any other provision in this Plan, no term of this Plan relating to ISOs will be interpreted, amended or altered, nor will any discretion or authority granted under this Plan be exercised, so as to disqualify this Plan under Section 422 of the Code or, without the consent of the Participant, to disqualify any Participant’s ISO under Section 422 of the Code.

5. RESTRICTED STOCK. A Restricted Stock Award is an offer by the Company to sell to an eligible person Shares that are subject to certain specified restrictions. The Committee will determine to whom an offer will be made, the number of Shares the person may purchase, the Purchase Price, the restrictions to which the Shares will be subject, and all other terms and conditions of the Restricted Stock Award, subject to the following terms and conditions.

5.1 Form of Restricted Stock Award. All purchases under a Restricted Stock Award made pursuant to this Plan will be evidenced by an Award Agreement (“Restricted Stock Purchase Agreement”) that will be in such form (which need not be the same for each Participant) as the Committee will from time to time approve, and will comply with and be subject to the terms and conditions of this Plan. The Restricted Stock Award will be accepted by the Participant’s execution and delivery of the Restricted Stock Purchase Agreement (accepted via written, electronic or other means) and full payment for the Shares to the Company within thirty (30) days from the date the Restricted Stock Purchase Agreement is delivered to the person. If such person does not execute and deliver the Restricted Stock Purchase Agreement along with full payment for the Shares to the Company within such thirty (30) days, then the offer will terminate, unless otherwise determined by the Committee.

4

5.2 Purchase Price. The Purchase Price of Shares sold pursuant to a Restricted Stock Award will be determined by the Committee on the date the Restricted Stock Award is granted. Payment of the Purchase Price must be made in accordance with Section 8 hereof.

5.3 Dividends and Other Distributions. Participants holding Restricted Stock Awards will be entitled to receive all dividends and other distributions paid with respect to such Shares, unless the Committee provides otherwise at the time the Award is granted. If any such dividends or distributions are paid in Shares, the Shares will be subject to the same restrictions on transferability and forfeitability as the Restricted Stock Awards with respect to which they were paid.

5.4 Restrictions. Restricted Stock Awards may be subject to the restrictions set forth in Sections 9 and 10 hereof.

6. RESTRICTED STOCK UNITS.

6.1 Awards of Restricted Stock Units. A Restricted Stock Unit (“RSU”) is an Award covering a number of Shares that may be settled in cash, by issuance of those Shares at a date in the future, or by a combination of cash and Shares. No Purchase Price shall apply to an RSU settled in Shares. All grants of RSUs will be evidenced by an Award Agreement (the “RSU Agreement”) that will be in such form (which need not be the same for each Participant) as the Committee will from time to time approve, and will comply with and be subject to the terms and conditions of this Plan. No RSU will have a term longer than ten (10) years from the date the RSU is granted.

6.2 Form and Timing of Settlement. To the extent permissible under applicable law, the Committee may permit a Participant to defer payment (including settlement) under an RSU to a date or dates after the RSU has vested, provided that the terms of the RSU and any deferral satisfy the requirements of Section 409A of the Code (or any successor) and any regulations or rulings promulgated thereunder, to the extent the Participant is subject to Section 409A of the Code. Payment may be made in the form of cash or whole Shares or a combination thereof, all as the Committee determines.

6.3 Dividend Equivalent Payments. The Board may permit Participants holding RSUs to receive dividend equivalent payments on outstanding RSUs if and when dividends are paid to stockholders on Shares. In the discretion of the Board, such dividend equivalent payments may be paid in cash or Shares and they may either be paid at the same time as dividend payments are made to stockholders or delayed until Shares are issued pursuant to the RSU grants and may be subject to the same vesting or performance requirements as the RSUs. If the Board permits dividend equivalent payments to be made on RSUs, the terms and conditions for such dividend equivalent payments will be set forth in the RSU Agreement.

7. STOCK APPRECIATION RIGHTS.

7.1 Awards of SARs. Stock Appreciation Rights (“SARs”) may be settled in cash or Shares (which may consist of Restricted Stock or RSUs) or a combination thereof, having a value equal to the value determined by multiplying the difference between the Fair Market Value on the date of exercise over the Exercise Price and the number of Shares with respect to which the SAR is being exercised. All grants of SARs made pursuant to this Plan will be evidenced by an Award Agreement (the “SAR Agreement”) that will be in such form (which need not be the same for each Participant) as the Committee will from time to time approve, and will comply with and be subject to the terms and conditions of this Plan.

5

7.2 Exercise Period and Expiration Date. A SAR will be exercisable within the times or upon the occurrence of events determined by the Committee and set forth in the SAR Agreement. The SAR Agreement shall set forth the expiration date; provided that no SAR will be exercisable after the expiration of ten (10) years from the date the SAR is granted.

7.3 Exercise Price. The Committee will determine the Exercise Price of the SAR when the SAR is granted, which may not be less than the Fair Market Value on the date of grant.

7.4 Termination. Subject to earlier termination pursuant to Sections 11 and 13 hereof and subject to any longer exercise periods set forth in the SAR Agreement, exercise of SARs will always be subject to the following terms and conditions.

7.4.1 Other than Death or Disability or for Cause. If the Participant is Terminated for any reason other than death, Disability or for Cause, then the Participant may exercise such Participant’s SARs only to the extent that such SARs are exercisable as to Vested Shares upon the Termination Date or as otherwise determined by the Committee or as required by applicable law. SARs must be exercised by the Participant, if at all, as to all or some of the Vested Shares calculated as of the Termination Date or such other date determined by the Committee, within three (3) months after the Termination Date (or within such shorter time period, not less than thirty (30) days, or within such longer time period after the Termination Date as may be determined by the Committee or as required by applicable law), but in any event no later than the expiration date of the SARs.

7.4.2 Death or Disability. If the Participant is Terminated because of Participant’s death or Disability (or the Participant dies within three (3) months after a Termination other than for Cause), then Participant’s SARs may be exercised only to the extent that such SARs are exercisable as to Vested Shares on the Termination Date or as otherwise determined by the Committee or as required by applicable law. Such SARs must be exercised by Participant (or Participant’s legal representative or authorized assignee), if at all, as to all or some of the Vested Shares calculated as of the Termination Date or such other date determined by the Committee, within twelve (12) months after the Termination Date (or within such shorter time period, not less than six (6) months, or within such longer time period after the Termination Date as may be determined by the Committee or as required by applicable law), but in any event no later than the expiration date of the SARs.

7.4.3 For Cause. If the Participant is Terminated for Cause, the Participant may exercise such Participant’s SARs, but not to an extent greater than such SARs are exercisable as to Vested Shares upon the Termination Date and Participant’s SARs shall expire on such Participant’s Termination Date, or at such later time and on such conditions as are determined by the Committee.

8. PAYMENT FOR PURCHASES AND EXERCISES.

8.1 Payment in General. Payment for Shares acquired pursuant to this Plan may be made in cash equivalents (including by check or Automated Clearing House (“ACH”) transfer) or, where expressly approved for the Participant by the Committee and subject to compliance with applicable law:

(a) by cancellation of indebtedness of the Company owed to the Participant;

(b) by surrender of shares of the Company that are clear of all liens, claims, encumbrances or security interests and: (i) for which the Company has received “full payment of the purchase price” within the meaning of SEC Rule 144 (and, if such shares were purchased from the Company by use of a promissory note, such note has been fully paid with respect to such shares) or (ii) that were obtained by Participant in the public market;

6

(c) by tender of a full recourse promissory note having such terms as may be approved by the Committee and bearing interest at a rate sufficient to avoid (i) imputation of income under Sections 483 and 1274 of the Code and (ii) unfavorable accounting treatment as determined by the Committee; provided, however, that Participants who are not employees or directors of the Company will not be entitled to purchase Shares with a promissory note unless the note is adequately secured by collateral other than the Shares; provided, further, that the portion of the Exercise Price or Purchase Price, as the case may be, equal to the par value (if any) of the Shares must be paid in cash or other legal consideration permitted by the laws under which the Company is then incorporated or organized;

(d) by waiver of compensation due or accrued to the Participant from the Company for services rendered;

(e) by participating in a formal cashless exercise program implemented by the Committee in connection with the Plan;

(f) provided that a public market for the Company’s common stock exists, by exercising through a “same day sale” commitment from the Participant and a broker-dealer whereby the Participant irrevocably elects to exercise the Award and to sell a portion of the Shares so purchased sufficient to pay the total Exercise Price or Purchase Price, and whereby the broker-dealer irrevocably commits upon receipt of such Shares to forward the total Exercise Price or Purchase Price directly to the Company; or

(g) by any combination of the foregoing or any other method of payment approved by the Committee.

For avoidance of uncertainty: ACH transfers that have been received by the Company into its bank account designated for receipt of such transfers under this Section 8.1 shall be deemed to have been received for all purposes under this Plan as of the date on which such transfers were initiated from the transferor’s account and made irrevocable by the transferor.

8.2 Withholding Taxes.

8.2.1 Withholding Generally. Whenever Shares are to be issued in satisfaction of Awards granted under this Plan, the Company may require the Participant to remit to the Company an amount sufficient to satisfy the maximum tax withholding requirements as to income tax, social insurance, payroll tax, fringe benefits tax, payment on account and other tax-related obligations (collectively, “Tax-Related Obligations”) prior to the delivery of any written or electronic certificate or certificates for such Shares. Whenever, under this Plan, payments in satisfaction of Awards are to be made in cash by the Company, such payment will be net of an amount sufficient to satisfy applicable tax withholding requirements.

8.2.2 Stock Withholding. When, under applicable tax laws, a Participant incurs tax liability in connection with the exercise or vesting of any Award that is subject to tax withholding and the Participant is obligated to pay the Company the amount required to be withheld, the Committee may in its sole discretion allow the Participant to satisfy up to the maximum Tax-Related Obligations in the employee’s applicable jurisdictions by electing to have the Company withhold from the Shares to be issued up to the number of Shares having a Fair Market Value on the date that the amount of tax to be withheld is to be determined that is not more than the maximum Tax-Related Obligations in the employee’s applicable jurisdictions; or to arrange a mandatory “sell to cover” on Participant’s behalf (without further authorization) but in no event will the Company withhold Shares or “sell to cover” if such withholding would result in adverse accounting or compliance consequences to the Company. The maximum Tax-Related Obligations are based on the applicable rates of the relevant tax authorities (for example, federal, state and local), including the employee’s share of payroll or similar taxes, as provided in the tax law, regulations or the authority’s administrative practices, not to exceed the highest statutory rate in that jurisdiction. Any elections to have Shares withheld or sold for this purpose will be made in accordance with the requirements established by the Committee for such elections and be in writing in a form acceptable to the Committee.

7

8.2.3 Elections Under Section 83(i) of the Code. A Participant will not make an election under Section 83(i) of the Code if the Company determines that the Participant is then ineligible to make such an election under applicable law or without the Company’s prior written consent (which will not be unreasonably withheld or delayed, but may be conditioned upon the Participant’s entry into additional commitments as determined by the Company).

9. RESTRICTIONS ON AWARDS.

9.1 Transferability. Except as permitted by the Committee, Awards granted under this Plan, and any interest therein, will not be transferable or assignable by Participant, other than by will or by the laws of descent and distribution, and, with respect to NQSOs for Participants in the U.S., by instrument to an inter vivos or testamentary trust in which the NQSOs are to be passed to beneficiaries upon the death of the trustor (settlor), or by gift to “family member” as that term is defined in Rule 701, and may not be made subject to execution, attachment or similar process. For the avoidance of doubt, the prohibition against assignment and transfer applies to Awards and any Shares underlying the Awards prior to the issuance of the Shares, and pursuant to the foregoing sentence shall be understood to include, without limitation, a prohibition against any pledge, hypothecation, or other transfer, including any short position, any “put equivalent position” or any “call equivalent position” (in each case, as defined in Rule 16a-1 promulgated under the Exchange Act). Unless an Award is transferred pursuant to the terms of this Section, during the lifetime of the Participant an Award will be exercisable only by the Participant or Participant’s legal representative and any elections with respect to an Award may be made only by the Participant or Participant’s legal representative. The terms of an Award shall be binding upon the executor, administrator, successors and assigns of the Participant who is a party thereto.

9.2 Securities Law and Other Regulatory Compliance. Although this Plan is intended to be a written compensatory benefit plan within the meaning of Rule 701 promulgated under the Securities Act, Awards may be made pursuant to this Plan that do not qualify for exemption under Rule 701. An Award will not be effective unless such Award is in compliance with all applicable U.S. and non-U.S. federal, state and local securities laws, rules and regulations of any governmental body, and the requirements of any stock exchange or automated quotation system upon which the Company’s equity securities may then be listed or quoted, as they are in effect on the date of grant of the Award and also on the date of exercise, settlement or other issuance. Notwithstanding any other provision in this Plan, the Company will have no obligation to issue Shares or deliver certificates for Shares under this Plan prior to (a) obtaining any approvals from governmental agencies that the Company determines are necessary or advisable, and/or (b) compliance with any exemption, completion of any registration or other qualification of such Shares under any U.S. and non-U.S. federal, state or local law or ruling of any governmental body that the Company determines to be necessary or advisable. The Company will be under no obligation to register the Shares with the SEC or to effect compliance with the exemption, registration, qualification or listing requirements of any securities laws, stock exchange or automated quotation system, and the Company will have no liability for any inability or failure to do so.

9.3 Exchange and Buyout of Awards. The Committee may, at any time or from time to time, authorize the Company, with the consent of the respective Participants, to issue new Awards in exchange for the surrender and cancellation of any or all outstanding Awards. Without prior stockholder approval the Committee may reprice Options or SARs (and where such repricing is a reduction in the Exercise Price of outstanding Options or SARs, the consent of the affected Participants is not required provided written notice is provided to them). The Committee may at any time buy from a Participant an Award previously granted with payment in cash, Shares (including Restricted Stock) or other consideration, based on such terms and conditions as the Committee and the Participant may agree.

8

10. RESTRICTIONS ON SHARES.

10.1 Privileges of Stock Ownership. No Participant will have any of the rights of a stockholder with respect to any Shares until such Shares are issued to the Participant. After Shares are issued to the Participant, the Participant will be a stockholder and have all the rights of a stockholder with respect to such Shares, including the right to vote and receive all dividends or other distributions made or paid with respect to such Shares; provided, that if such Shares are Restricted Stock, then any new, additional or different securities the Participant may become entitled to receive with respect to such Shares by virtue of a stock dividend, stock split or any other change in the corporate or capital structure of the Company will be subject to the same restrictions as the Restricted Stock. The Participant will have no right to retain such stock dividends or stock distributions with respect to Unvested Shares that are repurchased as described in this Section 10.

10.2 Rights of First Refusal and Repurchase. At the discretion of the Committee, the Company may reserve to itself and/or its assignee(s) in the Award Agreement (a) a right of first refusal to purchase all Shares that a Participant (or a subsequent transferee) may propose to transfer to a third party, provided that such right of first refusal terminates upon (i) subject to any applicable market standoff restrictions, the effective date of the first sale of common stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the SEC under the Securities Act (other than a registration statement relating solely to the issuance of common stock pursuant to a business combination or an employee incentive or benefit plan); (ii) any transfer or conversion of Shares made pursuant to a statutory merger or statutory consolidation of the Company with or into another corporation or corporations if the common stock of the surviving corporation or any direct or indirect Parent thereof is registered under the Exchange Act; or (iii) any transfer or conversion of Shares made pursuant to a statutory conversion of the Company into another form of legal entity if the common equity (or comparable equity security) of entity resulting from such conversion is registered under the Exchange Act; and (b) a right to repurchase Unvested Shares held by a Participant for cash and/or cancellation of purchase money indebtedness owed to the Company by the Participant following such Participant’s Termination at any time.

10.3 Agreement to Vote Shares. At the discretion of the Committee, the Company may require that, as a condition to the receipt of the Shares upon issuance of an Award, exercise of an Option or SAR or settlement of an RSU, the Participant and any transferee of the Shares agree to vote such Shares pursuant to the terms of a Voting Agreement by and between the Company and certain of its stockholders.

10.4 Escrow; Pledge of Shares. To enforce any restrictions on a Participant’s Shares, the Committee may require the Participant to deposit all written or electronic certificates representing Shares, together with stock powers or other instruments of transfer approved by the Committee, appropriately endorsed in blank, with the Company or an agent designated by the Company to hold in escrow until such restrictions have lapsed or terminated. The Committee may cause a legend or legends referencing such restrictions to be placed on the written or electronic certificate. Any Participant who is permitted to execute a promissory note as partial or full consideration for the purchase of Shares under this Plan will be required to pledge and deposit with the Company all or part of the Shares so purchased as collateral to secure the payment of Participant’s obligation to the Company under the promissory note; provided, however, that the Committee may require or accept other or additional forms of collateral to secure the payment of such obligation and, in any event, the Company will have full recourse against the Participant under the promissory note notwithstanding any pledge of the Participant’s Shares or other collateral. In connection with any pledge of the Shares, Participant will be required to execute and deliver a written pledge agreement in such form as the Committee will from time to time approve. The Shares purchased with the promissory note may be released from the pledge on a pro rata basis as the promissory note is paid.

9

10.5 Securities Law Restrictions. All written or electronic certificates for Shares or other securities delivered under this Plan will be subject to such stock transfer orders, legends and other restrictions as the Committee may deem necessary or advisable, including restrictions under any applicable U.S. and non-U.S. federal, state or local securities law, or any rules, regulations and other requirements of the SEC or any stock exchange or automated quotation system upon which the Company’s equity securities may be listed or quoted.

11. CORPORATE TRANSACTIONS.

11.1 Acquisitions or Other Combinations. In the event that the Company is subject to an Acquisition or Other Combination, outstanding Awards acquired under the Plan shall be subject to the agreement evidencing the Acquisition or Other Combination, which need not treat all outstanding Awards in an identical manner. Such agreement, without the Participant’s consent, shall provide for one or more of the following with respect to all outstanding Awards as of the effective date of such Acquisition or Other Combination:

(a) The continuation of such outstanding Awards by the Company (if the Company is the successor entity).

(b) The assumption of outstanding Awards by the successor or acquiring entity (if any) in such Acquisition or Other Combination (or by any of its Parents, if any), which assumption, will be binding on all Participants; provided that the exercise price and the number and nature of shares issuable upon exercise of any such option or stock appreciation right, or upon the settlement of any award that is subject to Section 409A of the Code, will be adjusted appropriately pursuant to Section 424(a) and Section 409A of the Code. For the purposes of this Section 11, an Award will be considered assumed if, following the Acquisition or Other Combination, the Award confers the right to purchase or receive, for each Share subject to the Award immediately prior to the Acquisition or Other Combination, the consideration (whether stock, cash, or other securities or property) received in the Acquisition or Other Combination by holders of Shares for each Share held on the effective date of the transaction (and if holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding Shares); provided, however, that if such consideration received in the Acquisition or Other Combination is not solely common stock of the successor corporation or its Parent, the Committee may, with the consent of the successor corporation, provide for the consideration to be received upon the exercise of an Option or Stock Appreciation Right or upon the settlement of an RSU, for each Share subject to such Award, to be solely common stock of the successor corporation or its Parent equal in fair market value to the per share consideration received by holders of Common Stock in the Acquisition or Other Combination.

(c) The substitution by the successor or acquiring entity in such Acquisition or Other Combination (or by any of its Parents, if any) of equivalent awards with substantially the same terms for such outstanding Awards (except that the exercise price and the number and nature of shares issuable upon exercise of any such option or stock appreciation right, or any award that is subject to Section 409A of the Code, will be adjusted appropriately pursuant to Section 424(a) and Section 409A of the Code).

(d) The full or partial exercisability or vesting and accelerated expiration of outstanding Awards.

(e) The settlement of the Fair Market Value of such outstanding Award (whether or not then vested or exercisable) in cash, cash equivalents, or securities of the successor entity (or its Parent, if any), followed by the cancellation of such Awards; provided however, that such Award may be cancelled without consideration if such Award has no value, as determined by the Committee, in its discretion. Subject to Section 409A of the Code, such payment may be made in installments and may be deferred until the date or dates when the Award would have become exercisable or vested. Such payment may be subject to vesting based on the Participant’s continued service, provided that without the Participant’s consent, the vesting schedule shall not be less favorable to the Participant than the schedule under which the Award would have become vested or exercisable. For purposes of this Section 11.1(e), the Fair Market Value of any security shall be determined without regard to any vesting conditions that may apply to such security.

10

(f) The termination in its entirety of any outstanding Award, without payment of any consideration, that is not exercised in accordance with its terms upon or prior to consummation of the transactions contemplated by the Acquisition or Other Combination within a time specified by the Committee, in its discretion, for such exercise, whether or not such Award is then fully exercisable.

Immediately following an Acquisition or Other Combination, outstanding Awards shall terminate and cease to be outstanding, except to the extent such Awards, have been continued, assumed or substituted, as described in Sections 11.1(a), (b) and/or (c).

11.2 Substitution or Assumption of Awards by the Company. The Company, from time to time, also may substitute or assume outstanding awards granted by another entity, whether in connection with an acquisition of such other entity or otherwise, by either (a) granting an Award under this Plan in substitution of such other entity’s award or (b) assuming and/or converting such award as if it had been granted under this Plan if the terms of such assumed award could be applied to an Award granted under this Plan. Such substitution or assumption will be permissible if the holder of the substituted or assumed award would have been eligible to be granted an Award under this Plan if the other entity had applied the rules of this Plan to such grant. In the event the Company assumes an award granted by another entity, the terms and conditions of such award will remain unchanged (except that the exercise price and the number and nature of shares issuable upon exercise of any such option or stock appreciation right, or any award that is subject to Section 409A of the Code, will be adjusted appropriately pursuant to Section 424(a) or Section 409A of the Code). In the event the Company elects to grant a new Option or SAR in substitution for and rather than assuming an existing option or stock appreciation right, such new Option or SAR may be granted with a similarly adjusted Exercise Price and number of underlying Shares and such other changes approved by the Committee, subject to the consent of the Participant.

12. ADMINISTRATION.

12.1 Committee Authority. This Plan will be administered by the Committee. Subject to the general purposes, terms and conditions of this Plan, and to the direction of the Board, the Committee will have full power to implement and carry out this Plan. Without limitation, the Committee will have the authority to:

(a) construe and interpret this Plan, any Award Agreement and any other agreement or document executed pursuant to this Plan;

(b) prescribe, amend, expand, modify and rescind or terminate rules and regulations relating to this Plan;

(c) approve persons to receive Awards;

(d) determine the form and terms of Awards;

(e) determine the number of Shares or other consideration subject to Awards granted under this Plan;

(f) determine the Fair Market Value in good faith and interpret the applicable provisions of this Plan and the definition of Fair Market Value in connection with circumstances that impact the Fair Market Value, if necessary;

11

(g) determine whether Awards will be granted singly, in combination with, in tandem with, in replacement of, or as alternatives to, other Awards under this Plan or awards under any other incentive or compensation plan of the Company or any Parent or Subsidiary of the Company;

(h) grant waivers of any conditions of this Plan or any Award;

(i) determine the terms of vesting, exercisability, settlement and payment of Awards to be granted pursuant to this Plan;

(j) correct any defect, supply any omission, or reconcile any inconsistency in this Plan, any Award, any Award Agreement or any Exercise Agreement;

(k) determine whether an Award has vested or become exercisable;

(l) extend the vesting period beyond a Participant’s Termination Date;

(m) adopt rules and/or procedures (including the adoption of any subplan under this Plan) relating to the operation and administration of the Plan to accommodate or facilitate requirements of local law and procedures outside of the United States;

(n) delegate any of the foregoing to a subcommittee consisting of one or more directors or executive officers pursuant to a specific delegation as may otherwise be permitted by applicable law;

(o) change the vesting schedule of Awards under the Plan prospectively in the event that the Participant’s service status changes between full and part time status in accordance with Company policies relating to work schedules and vesting of Awards; and

(p) make all other determinations necessary or advisable in connection with the administration of this Plan.

12.2 Standalone, Tandem and Substitute Awards. Awards granted under the Plan may, in the sole discretion of the Committee, be granted either alone or in addition to, in tandem with, or in substitution for, any other Award granted under the Plan. Awards granted in addition to or in tandem with other Awards may be granted either at the same time as or at a different time from the grant of such other Awards.

12.3 Committee Composition and Discretion. The Board may delegate full administrative authority over the Plan and Awards to a Committee consisting of at least one member of the Board (or such greater number as may then be required by applicable law). Unless in contravention of any express terms of this Plan or Award, any determination made by the Committee with respect to any Award will be made in its sole discretion either (a) at the time of grant of the Award, or (b) subject to Section 4.9 hereof, at any later time. Any such determination will be final and binding on the Company and on all persons having an interest in any Award under this Plan. To the extent permitted by applicable law, the Committee may delegate to one or more directors or officers of the Company the authority to grant an Award under this Plan.

12.4 Nonexclusivity of the Plan. Neither the adoption of this Plan by the Board, the submission of this Plan to the stockholders of the Company for approval, nor any provision of this Plan will be construed as creating any limitations on the power of the Board to adopt such additional compensation arrangements as it may deem desirable, including, without limitation, the granting of stock options and other equity awards otherwise than under this Plan, and such arrangements may be either generally applicable or applicable only in specific cases.

12

12.5 Governing Law. This Plan and all agreements hereunder shall be governed by and construed in accordance with the laws of the State of Delaware, without giving effect to that body of laws pertaining to conflict of laws.

13. EFFECTIVENESS, AMENDMENT AND TERMINATION OF THE PLAN.

13.1 Adoption and Stockholder Approval. This Plan will become effective on the date that it is adopted by the Board (the “Effective Date”). This Plan will be approved by the stockholders of the Company (excluding Shares issued pursuant to this Plan), consistent with applicable laws, within twelve (12) months before or after the Effective Date. Upon the Effective Date, the Committee may grant Awards pursuant to this Plan; provided, however, that: (a) no Option or SAR may be exercised prior to initial stockholder approval of this Plan; and (b) no Option or SAR granted pursuant to an increase in the number of Shares approved by the Board shall be exercised prior to the time such increase has been approved by the stockholders of the Company.

13.2 Term of Plan. Unless earlier terminated as provided herein, this Plan will automatically terminate ten (10) years after the Effective Date.

13.3 Amendment or Termination of Plan. Subject to Section 4.9 hereof, the Board may at any time (a) terminate or amend this Plan in any respect, including without limitation amendment of any form of Award Agreement or instrument to be executed pursuant to this Plan and (b) terminate any and all outstanding Options, SARs or RSUs upon a dissolution or liquidation of the Company, followed by the payment of creditors and the distribution of any remaining funds to the Company’s stockholders; provided, however, that the Board will not, without the approval of the stockholders of the Company, amend this Plan in any manner that requires such stockholder approval pursuant to the Code or the regulations promulgated under the Code as such provisions apply to ISO plans. The termination of the Plan, or any amendment thereof, shall not affect any Share previously issued or any Award previously granted under the Plan.

14. DEFINITIONS. For all purposes of this Plan, the following terms will have the following meanings.

“Acquisition,” for purposes of Section 11, means:

(a) any consolidation or merger in which the Company is a constituent entity or is a party in which the voting stock and other voting securities of the Company that are outstanding immediately prior to the consummation of such consolidation or merger represent, or are converted into, securities of the surviving entity of such consolidation or merger (or of any Parent of such surviving entity) that, immediately after the consummation of such consolidation or merger, together possess less than fifty percent (50%) of the total voting power of all voting securities of such surviving entity (or of any of its Parents, if any) that are outstanding immediately after the consummation of such consolidation or merger;

(b) a sale or other transfer by the holders thereof of outstanding voting stock and/or other voting securities of the Company possessing more than fifty percent (50%) of the total voting power of all outstanding voting securities of the Company, whether in one transaction or in a series of related transactions, pursuant to an agreement or agreements to which the Company is a party and that has been approved by the Board, and pursuant to which such outstanding voting securities are sold or transferred to a single person or entity, to one or more persons or entities who are Affiliates of each other, or to one or more persons or entities acting in concert; or

13

(c) the sale, lease, transfer or other disposition, in a single transaction or series of related transactions, by the Company and/or any Subsidiary or Subsidiaries of the Company, of all or substantially all the assets of the Company and its Subsidiaries taken as a whole (or, if substantially all of the assets of the Company and its Subsidiaries taken as a whole are held by one or more Subsidiaries, the sale or disposition (whether by consolidation, merger, conversion or otherwise) of such Subsidiaries of the Company), except where such sale, lease, transfer or other disposition is made to the Company or one or more wholly owned Subsidiaries of the Company.

Notwithstanding the foregoing, the following transactions shall not constitute an “Acquisition”: (1) the closing of the Company’s first public offering pursuant to an effective registration statement filed under the Securities Act or (2) any transaction the sole purpose of which is to change the state of incorporation of the Company or to create a holding company that will be owned in substantially the same proportions by the persons who held the Company’s securities immediately before such transaction.

“Affiliate” of a specified person means a person that directly, or indirectly through one or more intermediaries, controls or is controlled by, or is under common control with, the person specified (where, for purposes of this definition, the term “control” (including the terms “controlling,” “controlled by” and “under common control with”) means the possession, direct or indirect, of the power to direct or cause the direction of the management and policies of a person, whether through the ownership of voting securities, by contract, or otherwise.

“Award” means any award pursuant to the terms and conditions of this Plan, including any Option, Restricted Stock Unit, Stock Appreciation Right or Restricted Stock Award.

“Award Agreement” means, with respect to each Award, the executed written or electronic agreement between the Company and the Participant setting forth the terms and conditions of the Award as approved by the Committee. For purposes of the Plan, the Award Agreement may be accepted by a Participant via written, electronic or other means, subject to requirements under applicable law.

“Board” means the Board of Directors of the Company.

“Cause” means Termination because of (a) Participant’s unauthorized misuse of the Company or a Parent or Subsidiary of the Company’s trade secrets or proprietary information, (b) Participant’s conviction of or plea of nolo contendere to a felony or a crime involving moral turpitude, (c) Participant’s committing an act of fraud against the Company or a Parent or Subsidiary of the Company or (d) Participant’s gross negligence or willful misconduct in the performance of his or her duties that has had or will have a material adverse effect on the Company or Parent or Subsidiary of the Company’ reputation or business.

“Code” means the U.S. Internal Revenue Code of 1986, as amended.

“Committee” means the committee created and appointed by the Board to administer this Plan, or if no committee is created and appointed, the Board.

“Company” means Prelude Therapeutics Incorporated, a Delaware corporation, or any successor corporation.

“Disability” means a Participant is unable to perform the duties of his or her customary position of employment by reason of any medically determinable physical or mental impairment that can be expected to result in death or that can be expected to last for a continuous period of not less than twelve (12) months. The Committee may require such medical or other evidence as it deems necessary to judge the nature and permanency of the Participant’s condition.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Exercise Price” means the price per Share at which a holder of an Option or a SAR may purchase Shares issuable upon exercise of the Option or the SAR.

14

“Fair Market Value” means, as of any date, the value of a Share determined as follows:

(a) if such Share is then publicly traded on a national securities exchange, its closing price on the date of determination on the principal national securities exchange on which the Share is listed or admitted to trading as reported in The Wall Street Journal;

(b) if such Share is publicly traded but is not listed or admitted to trading on a national securities exchange, the average of the closing bid and ask prices on the date of determination as reported by The Wall Street Journal (or as otherwise reported by any newspaper or other source as the Committee may determine); or

(c) if none of the foregoing is applicable to the valuation in question, by the Committee in good faith.

“Option” means an award of an option to purchase Shares pursuant to Section 4 of this Plan.

“Other Combination” for purposes of Section 11 means any (a) consolidation or merger in which the Company is a constituent entity and is not the surviving entity of such consolidation or merger or (b) any conversion of the Company into another form of entity; provided that such consolidation, merger or conversion does not constitute an Acquisition.

“Parent” of a specified entity means, any entity that, either directly or indirectly, owns or controls such specified entity, where for this purpose, “control” means the ownership of stock, securities or other interests that possess at least a majority of the voting power of such specified entity (including indirect ownership or control of such stock, securities or other interests).

“Participant” means a person who receives an Award under this Plan.

“Plan” means this Amended and Restated 2016 Stock Incentive Plan, as amended from time to time.

“Purchase Price” means the price at which a Participant may purchase Restricted Stock pursuant to this Plan.

“Restricted Stock” means Shares purchased pursuant to a Restricted Stock Award under this Plan.

“Restricted Stock Award” means an award of Shares pursuant to Section 5 hereof.

“Restricted Stock Unit” or “RSU” means an award made pursuant to Section 6 hereof.

“Rule 701” means Rule 701 et seq. promulgated by the SEC under the Securities Act.

“SEC” means the U.S. Securities and Exchange Commission.

“Securities Act” means the U.S. Securities Act of 1933, as amended.

“Shares” means shares of the Company’s Common Stock, $0.0001 par value per share, reserved for issuance under this Plan, as adjusted pursuant to Sections 2.2 and 11 hereof, and any successor security.

“Stock Appreciation Right” or “SAR” means an award granted pursuant to Section 7 hereof.

15

“Subsidiary” means any entity (other than the Company) in an unbroken chain of entities beginning with the Company if each of the entities other than the last entity in the unbroken chain owns stock or other equity securities representing fifty percent (50%) or more of the total combined voting power of all classes of stock or other equity securities in one of the other entities in such chain.

“Termination” or “Terminated” means, for purposes of this Plan with respect to a Participant, that the Participant has for any reason ceased to provide services as an employee, officer, director or consultant to the Company or a Parent or Subsidiary of the Company. A Participant will not be deemed to have ceased to provide services while the Participant is on a bona fide leave of absence, if such leave was approved by the Company in writing. In the case of an approved leave of absence, the Committee may make such provisions respecting crediting of service, including suspension of vesting of the Award (including pursuant to a formal policy adopted from time to time by the Company) it may deem appropriate. The Committee will have sole discretion to determine whether a Participant has ceased to provide services and the effective date on which the Participant ceased to provide services (the “Termination Date”).

“Unvested Shares” means “Unvested Shares” as defined in the Award Agreement for an Award.

“Vested Shares” means “Vested Shares” as defined in the Award Agreement for an Award.

* * * * * * * * * * *

16

EARLY EXERCISE FORM

OPTION GRANT NO. ___

NOTICE OF STOCK OPTION GRANT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

The Optionee named below (“Optionee”) has been granted an option (this “Option”) to purchase shares of Common Stock, $0.0001 par value per share (the “Common Stock”), of Prelude Therapeutics Incorporated, a Delaware corporation (the “Company”), pursuant to the Company’s 2016 Stock Incentive Plan, as amended from time to time (the “Plan”) on the terms, and subject to the conditions, described below and in the Stock Option Agreement attached hereto as Exhibit A, including its annexes (the “Stock Option Agreement”).

Vesting Schedule [EXAMPLE ONLY]: For so long as Optionee continuously provides services to the Company (or any Subsidiary or Parent of the Company) as an employee, officer, director, contractor or consultant, the Shares subject to this Option will vest as follows: (a) prior to the first one (1) year anniversary of the Vesting Start Date, none of the Shares will be vested; (b) [1/4^th] of the Shares will be vested on the one (1) year anniversary of the Vesting Start Date; and (c) thereafter, this Option will become vested and exercisable with respect to an additional [1/48^th] of the Shares when Optionee completes each month of continuous service following the first one (1) year anniversary of the Vesting Start Date.

General; Agreement: By their signatures below, Optionee and the Company agree that this Option is granted under and governed by this Notice of Stock Option Grant (this “Grant Notice”) and by the provisions of the Plan and the Stock Option Agreement. The Plan and the Stock Option Agreement are incorporated herein by reference. Capitalized terms used but not defined herein shall have the meanings given to them in the Plan or in the Stock Option Agreement, as applicable. By signing below, Optionee acknowledges receipt of a copy of this Grant Notice, the Plan and the Stock Option Agreement, represents that Optionee has carefully read and is familiar with their provisions, and hereby accepts the Option subject to all of their respective terms and conditions. Optionee acknowledges that there may be adverse tax consequences upon exercise of the Option or disposition of the Shares and that Optionee should consult a tax adviser prior to such exercise or disposition. Optionee agrees and acknowledges that the Vesting Schedule may change prospectively in the event that Optionee’s service status changes between full and part time status in accordance with Company policies relating to work schedules and vesting of equity awards.

Execution and Delivery: This Grant Notice may be executed and delivered electronically whether via the Company’s intranet or the Internet site of a third party or via email or any other means of electronic delivery specified by the Company. By Optionee’s acceptance hereof (whether written, electronic or otherwise), Optionee agrees, to the fullest extent permitted by law, that in lieu of receiving documents in paper format, Optionee accepts the electronic delivery of any documents that the Company (or any third party the Company may designate), may deliver in connection with this grant (including the Plan, this Grant Notice, the Stock Option Agreement, the information described in Rules 701(e)(2), (3), (4) and (5) under the Securities Act (the “701 Disclosures”), account statements, or other communications or information) whether via the Company’s intranet or the Internet site of such third party or via email or such other means of electronic delivery specified by the Company.

Exhibit A

Stock Option Agreement

EXHIBIT A

EARLY EXERCISE FORM

STOCK OPTION AGREEMENT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

This Stock Option Agreement (this “Agreement”) is made and entered into as of the date of grant (the “Date of Grant”) set forth on the Notice of Stock Option Grant attached as the facing page to this Agreement (the “Grant Notice”) by and between Prelude Therapeutics Incorporated, a Delaware corporation (the “Company”), and the optionee named on the Grant Notice (“Optionee”). Capitalized terms not defined in this Agreement shall have the meaning ascribed to them in the Company’s 2016 Stock Incentive Plan, as amended from time to time (the “Plan”), or in the Grant Notice, as applicable.

1. GRANT OF OPTION. The Company hereby grants to Optionee an option (this “Option”) to purchase up to the total number of shares of Common Stock of the Company, $0.0001 par value per share (the “Common Stock”), set forth in the Grant Notice as the Shares (the “Shares”) at the Exercise Price Per Share set forth in the Grant Notice (the “Exercise Price”), subject to all of the terms and conditions of the Grant Notice, this Agreement and the Plan. If designated as an Incentive Stock Option in the Grant Notice, this Option is intended to qualify as an incentive stock option (the “ISO”) within the meaning of Section 422 of the Internal Revenue Code of 1986, as amended (the “Code”), except that if on the Date of Grant Optionee is not subject to U.S. income tax, then this Option shall be a NQSO.

2. EXERCISE PERIOD.

2.1. Exercise Period of Option. Subject to the conditions set forth in this Agreement, all or part of this Option may be exercised at any time after the Date of Grant. Shares purchased by exercising this Option may be subject to the Repurchase Option as set forth in Section 7 below. This Option will become vested during its term as to portions of the Shares in accordance with the Vesting Schedule set forth in the Grant Notice. Notwithstanding any provision in the Plan or this Agreement to the contrary, on or after Optionee’s Termination Date, this Option may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date.

2.2. Vesting of Option Shares. Shares with respect to which this Option is vested at a given time pursuant to the Vesting Schedule set forth in the Grant Notice are “Vested Shares.” Shares with respect to which this Option is not vested at a given time pursuant to the Vesting Schedule set forth in the Grant Notice are “Unvested Shares.”

2.3. Expiration. The Option shall expire on the Expiration Date set forth in the Grant Notice or earlier as provided in Section 3 below.

3. TERMINATION.

3.1. Termination for Any Reason Except Death, Disability or Cause. Except as provided in subsection 3.2 in a case in which Optionee dies within three (3) months after Optionee is Terminated other than for Cause, if Optionee is Terminated for any reason (other than Optionee’s death or Disability or for Cause), then (a) on and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date and (b) this Option to the extent (and only to the extent) that it is exercisable with respect to Vested Shares on Optionee’s Termination Date, may be exercised by Optionee no later than three (3) months after Optionee’s Termination Date (but in no event may this Option be exercised after the Expiration Date).

3.2. Termination Because of Death or Disability. If Optionee is Terminated because of Optionee’s death or Disability (or if Optionee dies within three (3) months of the date of Optionee’s Termination for any reason other than for Cause), then (a) on and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date and (b) this Option, to the extent (and only to the extent) that it is exercisable with respect to Vested Shares on Optionee’s Termination Date, may be exercised by Optionee (or Optionee’s legal representative) no later than twelve (12) months after Optionee’s Termination Date, but in no event later than the Expiration Date. Any exercise of this Option beyond (i) three (3) months after the date Optionee ceases to be an employee when Optionee’s Termination is for any reason other than Optionee’s death or disability, within the meaning of Section 22(e)(3) of the Code; or (ii) twelve (12) months after the date Optionee ceases to be an employee when the termination is for Optionee’s disability, within the meaning of Section 22(e)(3) of the Code, is deemed to be an NQSO.

3.3. Termination for Cause. If Optionee is Terminated for Cause, then Optionee may exercise this Option, but only with respect to any Shares that are Vested Shares on Optionee’s Termination Date, and this Option shall expire on Optionee’s Termination Date, or at such later time and on such conditions as may be affirmatively determined by the Committee. On and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date.

3.4. No Obligation to Employ. Nothing in the Plan or this Agreement shall confer on Optionee any right to continue in the employ of, or other relationship with, the Company or any Parent or Subsidiary of the Company, or limit in any way the right of the Company or any Parent or Subsidiary of the Company to terminate Optionee’s employment or other relationship at any time, with or without Cause.

4. MANNER OF EXERCISE.

4.1. Stock Option Exercise Notice and Agreement. To exercise this Option, Optionee (or in the case of exercise after Optionee’s death or incapacity, Optionee’s executor, administrator, heir or legatee, as the case may be) must deliver to the Company an executed Stock Option Exercise Notice and Agreement in the form attached hereto as Annex A, or in such other form as may be approved by the Committee from time to time (the “Exercise Agreement”) and payment for the shares being purchased in accordance with this Agreement. The Exercise Agreement shall set forth, among other things, (i) Optionee’s election to exercise this Option, (ii) the number of Shares being purchased, (iii) any representations, warranties and agreements regarding Optionee’s investment intent and access to information as may be required by the Company to comply with applicable securities laws in connection with any exercise of this Option and (iv) any other agreements required by the Company. If someone other than Optionee exercises this Option, then such person must submit documentation reasonably acceptable to the Company verifying that such person has the legal right to exercise this Option and such person shall be subject to all of the restrictions contained herein as if such person were Optionee.

4.2. Limitations on Exercise. This Option may not be exercised unless such exercise is in compliance with all applicable federal and state securities laws, as they are in effect on the date of exercise.

4.3. Payment. The Exercise Agreement shall be accompanied by full payment of the Exercise Price for the shares being purchased in cash (by check, Automated Clearing House (“ACH”) or wire transfer), or where permitted by law:

(a) by cancellation of indebtedness of the Company owed to Optionee;

(b) by surrender of shares of the Company that are free and clear of all security interests, pledges, liens, claims or encumbrances and: (i) for which the Company has received “full payment of the purchase price” within the meaning of SEC Rule 144 (and, if such shares were purchased from the Company by use of a promissory note, such note has been fully paid with respect to such shares) or (ii) that were obtained by Optionee in the public market;

2

(c) by participating in a formal cashless exercise program implemented by the Committee in connection with the Plan;

(d) provided that a public market for the Common Stock exists, subject to compliance with applicable law, by exercising as set forth below, through a “same day sale” commitment from Optionee and a broker-dealer whereby Optionee irrevocably elects to exercise this Option and to sell a portion of the Shares so purchased sufficient to pay the total Exercise Price, and whereby the broker-dealer irrevocably commits upon receipt of such Shares to forward the total Exercise Price directly to the Company; or

(e) by any combination of the foregoing or any other method of payment approved by the Committee that constitutes legal consideration for the issuance of Shares.

For avoidance of uncertainty: ACH transfers that have been received by the Company into its bank account designated for receipt of such transfers shall be deemed to have been received for all purposes of this Option as of the date on which such transfers were initiated from the Optionee’s account and made irrevocable by Optionee.

4.4. Tax Withholding. Prior to the issuance of the Shares upon exercise of the Option, Optionee must pay or provide for foreign, federal, state and local income tax, social insurance, payroll tax, fringe benefits tax, payment on account withholding and other tax-related items related to Optionee’s participation in the Plan and legally applicable to Optionee, including, as applicable, obligations of the Company (all the foregoing tax-related items, “Tax-Related Items”). If the Committee permits, Optionee may provide for payment of withholding taxes upon exercise of the Option by requesting that the Company retain the number of Shares with a Fair Market Value equal to the amount of taxes required to be withheld; or to arrange a mandatory “sell to cover” on Optionee’s behalf (without further authorization); but in no event will the Company withhold Shares or “sell to cover” if such withholding would result in adverse accounting consequences to the Company. In case of stock withholding or a sell to cover, the Company shall issue the net number of Shares to Optionee by deducting the Shares retained from the Shares issuable upon exercise. The Company may withhold or account for Tax-Related Items by considering applicable minimum statutory withholding rates or other applicable statutory rates in Optionee’s country, including maximum applicable rates.

4.5. Issuance of Shares. Provided that the Exercise Agreement and payment are in form and substance satisfactory to counsel for the Company, the Company shall issue the Shares issuable upon a valid exercise of this Option registered in the name of Optionee, Optionee’s authorized assignee, or Optionee’s legal representative, and shall deliver certificates representing the Shares with the appropriate legends affixed thereto.

5. COMPLIANCE WITH LAWS AND REGULATIONS. The Plan and this Agreement are intended to comply with Rule 701. Any provision of this Agreement that is inconsistent with Rule 701 shall, without further act or amendment by the Company or the Committee, be reformed to comply with the requirements of Rule 701. The exercise of this Option and the issuance and transfer of Shares shall be subject to compliance by the Company and Optionee with all applicable requirements of federal and state securities laws and with all applicable requirements of any stock exchange on which the Common Stock may be listed at the time of such issuance or transfer. Optionee understands that the Company is under no obligation to register or qualify the Shares with the SEC, any state securities commission or any stock exchange to effect such compliance.

6. NONTRANSFERABILITY OF OPTION. This Option may not be transferred in any manner other than by will or by the laws of descent and distribution, and, with respect to NQSOs, by instrument to a testamentary trust in which the options are to be passed to beneficiaries upon the death of the trustor (settlor) or a revocable trust, or by gift to “immediate family” as that term is defined in 17 C.F.R. 240.16a-1(e), and may be exercised during the lifetime of Optionee only by Optionee or in the event of Optionee’s incapacity, by Optionee’s legal representative. The terms of this Option shall be binding upon the executors, administrators, successors and assigns of Optionee.

3

7. COMPANY’S REPURCHASE OPTION FOR UNVESTED SHARES. If Optionee is Terminated for any reason, or no reason, including without limitation, Optionee’s death, Disability, voluntary resignation or termination by the Company with or without Cause and Optionee has acquired Unvested Shares by exercising this Option, then the Company and/or its assignee(s) shall have the option to repurchase all or a portion of Optionee’s Unvested Shares (as defined in Section 2.2 of this Agreement) as of the Termination Date on the terms and conditions set forth in this Section 7 (the “Repurchase Option”).

7.1. Termination and Termination Date. In case of any dispute as to whether Optionee is Terminated, the Committee shall have discretion to determine whether Optionee has been Terminated and the effective date of such Termination (the “Termination Date”).

7.2. Exercise of Repurchase Option. Subject to the foregoing provisions of this Section, at any time within ninety (90) days after Optionee’s Termination Date, the Company and/or its assignee(s), may elect to repurchase any or all of Optionee’s Unvested Shares by giving Optionee written notice of exercise of the Repurchase Option.

7.3. Calculation of Repurchase Price for Unvested Shares. The Company or its assignee shall have the option to repurchase from Optionee (or from Optionee’s personal representative as the case may be) the Unvested Shares at Optionee’s Exercise Price, as such may be proportionately adjusted for any stock split or similar change in the capital structure of the Company as set forth in Section 2.2 of the Plan (the “Repurchase Price”).

7.4. Payment of Repurchase Price. The Repurchase Price shall be payable, at the option of the Company or its assignee, by check or by cancellation of all or a portion of any outstanding indebtedness owed by Optionee to the Company and/or such assignee, or by any combination thereof. The Repurchase Price shall be paid without interest within the term of the Repurchase Option as described in Section 7.2.

7.5. Right of Termination Unaffected. Nothing in this Agreement shall be construed to limit or otherwise affect in any manner whatsoever the right or power of the Company (or any Parent or Subsidiary of the Company) to terminate Optionee’s employment or other relationship with Company (or any Parent or Subsidiary of the Company) at any time, for any reason or no reason, with or without Cause.

8. RESTRICTIONS ON TRANSFER.

8.1. Disposition of Shares. Optionee hereby agrees that Optionee shall make no disposition of any of the Shares (other than as permitted by this Agreement) unless and until:

(a) Optionee shall have notified the Company of the proposed disposition and provided a written summary of the terms and conditions of the proposed disposition;

(b) Optionee shall have complied with all requirements of this Agreement applicable to the disposition of the Shares;

(c) Optionee shall have provided the Company with written assurances, in form and substance satisfactory to counsel for the Company, that (i) the proposed disposition does not require registration of the Shares under the Securities Act or under any applicable state securities laws or (ii) all appropriate actions necessary for compliance with the registration requirements of the Securities Act or of any exemption from registration available under the Securities Act (including Rule 144) or applicable state securities laws have been taken; and

(d) Optionee shall have provided the Company with written assurances, in form and substance satisfactory to the Company, that the proposed disposition will not result in the contravention of any transfer restrictions applicable to the Shares pursuant to the provisions of the regulations promulgated under Rule 701 or under any other applicable securities laws or adversely affect the Company’s ability to rely on the exemption(s) from registration under the Securities Act or under any other applicable securities laws for the grant of the Option, the issuance of Shares thereunder or any other issuance of securities under the Plan.

4

8.2. Restriction on Transfer. Optionee shall not transfer, assign, grant a lien or security interest in, pledge, hypothecate, encumber or otherwise dispose of any of the Shares which are subject to the Company’s Repurchase Option or the Right of First Refusal described below, except as permitted by this Agreement.

8.3. Transferee Obligations. Each person (other than the Company) to whom the Shares are transferred by means of one of the permitted transfers specified in this Agreement must, as a condition precedent to the validity of such transfer, acknowledge in writing to the Company that such person is bound by the provisions of this Agreement and that the transferred Shares are subject to (i) both the Company’s Repurchase Option and the Company’s Right of First Refusal granted hereunder and (ii) the market stand-off provisions of Section 9 below, to the same extent such Shares would be so subject if retained by Optionee.

9. MARKET STANDOFF AGREEMENT. Optionee agrees that, subject to any early release provisions that apply pro rata to stockholders of the Company according to their holdings of Common Stock (determined on an as-converted into Common Stock basis), Optionee will not, for a period of up to one hundred eighty (180) days (plus up to an additional thirty five (35) days to the extent reasonably requested by the Company or such underwriter(s) to accommodate regulatory restrictions on the publication or other distribution of research reports or earnings releases by the Company, including NASD and NYSE rules) following the effective date of the registration statement filed with the SEC relating to the initial underwritten sale of Common Stock of the Company to the public under the Securities Act (the “IPO”), directly or indirectly sell, offer to sell, grant any option for the sale of, or otherwise dispose of any Common Stock or securities convertible into Common Stock, except for: (i) transfers of Shares permitted under Section 10.6 hereof so long as such transferee furnishes to the Company and the managing underwriter their written consent to be bound by this Section 9 as a condition precedent to such transfer; and (ii) sales of any securities to be included in the registration statement for the IPO. For the avoidance of doubt, the provisions of this Section shall only apply to the IPO. The restricted period shall in any event terminate two (2) years after the closing date of the IPO. In order to enforce the foregoing covenant, the Company shall have the right to place restrictive legends on the certificates representing the Shares subject to this Section and to impose stop transfer instructions with respect to the Shares until the end of such period. Optionee further agrees to enter into any agreement reasonably required by the underwriters to implement the foregoing restrictions on transfer. For the avoidance of doubt, the foregoing provisions of this Section shall not apply to any registration of securities of the Company (a) under an employee benefit plan or (b) in a merger, consolidation, business combination or similar transaction.

10. COMPANY’S RIGHT OF FIRST REFUSAL. Unvested Shares may not be sold or otherwise transferred, or pledged by Optionee or made subject to a security interest, pledge or other lien without the Company’s prior written consent, which may be withheld in the Company’s sole and absolute discretion. Before any Vested Shares held by Optionee or any transferee of such Vested Shares (either sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including, without limitation, a transfer by gift or operation of law), the Company and/or its assignee(s) will have a right of first refusal to purchase the Vested Shares to be sold or transferred (the “Offered Shares”) on the terms and conditions set forth in this Section (the “Right of First Refusal”).

10.1. Notice of Proposed Transfer. The Holder of the Offered Shares will deliver to the Company a written notice (the “Notice”) stating: (i) the Holder’s bona fide intention to sell or otherwise transfer the Offered Shares; (ii) the name and address of each proposed purchaser or other transferee (the “Proposed Transferee”); (iii) the number of Offered Shares to be transferred to each Proposed Transferee; (iv) the bona fide cash price or other consideration for which the Holder proposes to transfer the Offered Shares (the “Offered Price”); and (v) that the Holder acknowledges this Notice is an offer to sell the Offered Shares to the Company and/or its assignee(s) pursuant to the Company’s Right of First Refusal at the Offered Price as provided for in this Agreement.

5

10.2. Exercise of Right of First Refusal. At any time within thirty (30) days after the date of the Notice, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all (or, with the consent of the Holder, less than all) the Offered Shares proposed to be transferred to any one or more of the Proposed Transferees named in the Notice, at the purchase price, determined as specified below.

10.3. Purchase Price. The purchase price for the Offered Shares purchased under this Section will be the Offered Price, provided that if the Offered Price consists of no legal consideration (as, for example, in the case of a transfer by gift) then the purchase price will be the fair market value of the Offered Shares as determined in good faith by the Committee. If the Offered Price includes consideration other than cash, then the value of the non-cash consideration, as determined in good faith by the Committee, will conclusively be deemed to be the cash equivalent value of such non-cash consideration.

10.4. Payment. Payment of the purchase price for the Offered Shares will be payable, at the option of the Company and/or its assignee(s) (as applicable), by check or by cancellation of all or a portion of any outstanding purchase money indebtedness owed by the Holder to the Company (or to such assignee, in the case of a purchase of Offered Shares by such assignee) or by any combination thereof. The purchase price will be paid without interest within sixty (60) days after the Company’s receipt of the Notice, or, at the option of the Company and/or its assignee(s), in the manner and at the time(s) set forth in the Notice.

10.5. Holder’s Right to Transfer. If all of the Offered Shares proposed in the Notice to be transferred to a given Proposed Transferee are not purchased by the Company and/or its assignee(s) as provided in this Section, then the Holder may sell or otherwise transfer such Offered Shares to each Proposed Transferee at the Offered Price or at a higher price, provided that (i) such sale or other transfer is consummated within ninety (90) days after the date of the Notice, (ii) any such sale or other transfer is effected in compliance with all applicable securities laws, and (iii) each Proposed Transferee agrees in writing that the provisions of this Section will continue to apply to the Offered Shares in the hands of such Proposed Transferee. If the Offered Shares described in the Notice are not transferred to each Proposed Transferee within such ninety (90) day period, then a new Notice must be given to the Company pursuant to which the Company will again be offered the Right of First Refusal before any Shares held by the Holder may be sold or otherwise transferred.

10.6. Exempt Transfers. Notwithstanding anything to the contrary in this Section, the following transfers of Vested Shares will be exempt from the Right of First Refusal: (i) the transfer of any or all of the Vested Shares during Optionee’s lifetime by gift or on Optionee’s death by will or intestacy to any member(s) of Optionee’s “Immediate Family” (as defined below) or to a trust for the benefit of Optionee and/or member(s) of Optionee’s Immediate Family, provided that each transferee or other recipient agrees in a writing satisfactory to the Company that the provisions of this Section will continue to apply to the transferred Vested Shares in the hands of such transferee or other recipient; (ii) any transfer of Vested Shares made pursuant to a statutory merger, statutory consolidation of the Company with or into another corporation or corporations or a conversion of the Company into another form of legal entity (except that the Right of First Refusal will continue to apply thereafter to such Vested Shares, in which case the surviving corporation of such merger or consolidation or the resulting entity of such conversion shall succeed to the rights of the Company under this Section unless the agreement of merger or consolidation or conversion expressly otherwise provides); or (iii) any transfer of Vested Shares pursuant to the winding up and dissolution of the Company. As used herein, the term “Immediate Family” will mean Optionee’s spouse, the lineal descendant or antecedent, father, mother, brother or sister, child, adopted child, grandchild or adopted grandchild of Optionee or Optionee’s spouse, or the spouse of any of the above or Spousal Equivalent, as defined herein. As used herein, a person is deemed to be a “Spousal Equivalent” provided the following circumstances are true: (i) irrespective of whether or not Optionee and the Spousal Equivalent are the same sex, they are the sole spousal equivalent of the other for the last twelve (12) months, (ii) they intend to remain so indefinitely, (iii) neither are married to anyone else, (iv) both are at least 18 years of age and mentally competent to consent to contract, (v) they are not related by blood to a degree of closeness that which would prohibit legal marriage in the state in which they legally reside, (vi) they are jointly responsible for each other’s common welfare and financial obligations, and (vii) they reside together in the same residence for the last twelve (12) months and intend to do so indefinitely.

6

10.7. Termination of Right of First Refusal. The Right of First Refusal will terminate as to all Shares: (i) on the effective date of the first sale of Common Stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the SEC under the Securities Act (other than a registration statement relating solely to the issuance of Common Stock pursuant to a business combination or an employee incentive or benefit plan); (ii) on any transfer or conversion of Shares made pursuant to a statutory merger or statutory consolidation of the Company with or into another corporation or corporations if the common stock of the surviving corporation or any direct or indirect parent corporation thereof is registered under the Exchange Act; or (iii) on any transfer or conversion of Shares made pursuant to a statutory conversion of the Company into another form of legal entity if the common equity (or comparable equity security) of entity resulting from such conversion is registered under the Exchange Act.

10.8. Encumbrances on Vested Shares. Optionee may grant a lien or security interest in, or pledge, hypothecate or encumber Vested Shares only if each party to whom such lien or security interest is granted, or to whom such pledge, hypothecation or other encumbrance is made, agrees in a writing satisfactory to the Company that: (i) such lien, security interest, pledge, hypothecation or encumbrance will not adversely affect or impair the Right of First Refusal or the rights of the Company and/or its assignee(s) with respect thereto and will not apply to such Vested Shares after they are acquired by the Company and/or its assignees under this Section; and (ii) the provisions of this Agreement will continue to apply to such Vested Shares in the hands of such party and any transferee of such party. Optionee may not grant a lien or security interest in, or pledge, hypothecate or encumber, any Unvested Shares.

11. RIGHTS AS A STOCKHOLDER. Optionee shall not have any of the rights of a stockholder with respect to any Shares unless and until such Shares are issued to Optionee. Subject to the terms and conditions of this Agreement, Optionee will have all of the rights of a stockholder of the Company with respect to the Shares from and after the date that Shares are issued to Optionee pursuant to, and in accordance with, the terms of the Exercise Agreement until such time as Optionee disposes of the Shares or the Company and/or its assignee(s) exercise(s) the Repurchase Option or the Right of First Refusal. Upon an exercise of the Repurchase Option or the Right of First Refusal, Optionee will have no further rights as a holder of the Shares so purchased upon such exercise, other than the right to receive payment for the Shares so purchased in accordance with the provisions of this Agreement, and Optionee will promptly surrender the stock certificate(s) evidencing the Shares so purchased to the Company for transfer or cancellation.

12. ESCROW. As security for Optionee’s faithful performance of this Agreement, Optionee agrees, immediately upon receipt of the stock certificate(s) evidencing the Shares, to deliver such certificate(s) to the Secretary of the Company or other designee of the Company (the “Escrow Holder”), who is hereby appointed to hold such certificate(s) and to take all such actions and to effectuate all such transfers and/or releases of such Shares as are in accordance with the terms of this Agreement. Optionee and the Company agree that Escrow Holder will not be liable to any party to this Agreement (or to any other party) for any actions or omissions unless Escrow Holder is grossly negligent or intentionally fraudulent in carrying out the duties of Escrow Holder under this Agreement. Escrow Holder may rely upon any letter, notice or other document executed with any signature purported to be genuine and may rely on the advice of counsel and obey any order of any court with respect to the transactions contemplated by this Agreement and will not be liable for any act or omission taken by Escrow Holder in good faith reliance on such documents, the advice of counsel or a court order. The Shares will be released from escrow upon termination of both the Repurchase Option and the Right of First Refusal.

7

13. RESTRICTIVE LEGENDS AND STOP-TRANSFER ORDERS.

13.1. Legends. Optionee understands and agrees that the Company will place the legends set forth below or similar legends on any stock certificate(s) evidencing the Shares, together with any other legends that may be required by state or U.S. Federal securities laws, the Company’s Certificate of Incorporation or Bylaws, any other agreement between Optionee and the Company, or any agreement between Optionee and any third party (and any other legend(s) that the Company may become obligated to place on the stock certificate(s) evidencing the Shares under the terms of any agreement to which the Company is or may become bound or obligated):

(a) THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR UNDER THE SECURITIES LAWS OF CERTAIN STATES. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. INVESTORS SHOULD BE AWARE THAT THEY MAY BE REQUIRED TO BEAR THE FINANCIAL RISKS OF THIS INVESTMENT FOR AN INDEFINITE PERIOD OF TIME. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

(b) THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON RESALE AND TRANSFER, INCLUDING THE REPURCHASE OPTION AND RIGHT OF FIRST REFUSAL HELD BY THE ISSUER AND/OR ITS ASSIGNEE(S) AS SET FORTH IN A STOCK OPTION AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH SALE AND TRANSFER RESTRICTIONS, INCLUDING THE REPURCHASE OPTION AND RIGHT OF FIRST REFUSAL, ARE BINDING ON TRANSFEREES OF THESE SHARES.

(c) THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A MARKET STANDOFF RESTRICTION AS SET FORTH IN A CERTAIN STOCK OPTION AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. AS A RESULT OF SUCH AGREEMENT, THESE SHARES MAY NOT BE TRADED PRIOR TO 180 DAYS AFTER THE EFFECTIVE DATE OF CERTAIN PUBLIC OFFERINGS OF THE COMMON STOCK OF THE ISSUER HEREOF. SUCH RESTRICTION IS BINDING ON TRANSFEREES OF THESE SHARES.

13.2. Stop-Transfer Instructions. Optionee agrees that, to ensure compliance with the restrictions imposed by this Agreement, the Company may issue appropriate “stop-transfer” instructions to its transfer agent, if any, and if the Company transfers its own securities, it may make appropriate notations to the same effect in its own records.

13.3. Refusal to Transfer. The Company will not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares, or to accord the right to vote or pay dividends to any purchaser or other transferee to whom such Shares have been so transferred.

14. CERTAIN TAX CONSEQUENCES. Set forth below is a brief summary as of the Effective Date of the Plan of some of the federal tax consequences of exercise of the Option and disposition of the Shares. THIS SUMMARY IS NECESSARILY INCOMPLETE, AND THE TAX LAWS AND REGULATIONS ARE SUBJECT TO CHANGE. OPTIONEE SHOULD CONSULT A TAX ADVISER BEFORE EXERCISING THE OPTION OR DISPOSING OF THE SHARES.

14.1. Exercise of ISO. If the Option qualifies as an ISO, there will be no regular federal income tax liability upon the exercise of the Option, although the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price will be treated as a tax preference item for federal alternative minimum tax purposes and may subject Optionee to the alternative minimum tax in the year of exercise.

8

14.2. Exercise of Nonqualified Stock Option. If the Option does not qualify as an ISO, there may be a regular federal income tax liability upon the exercise of the Option. Optionee will be treated as having received compensation income (taxable at ordinary income tax rates) equal to the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price. If Optionee is a current or former employee of the Company, the Company may be required to withhold from Optionee’s compensation or collect from Optionee and pay to the applicable taxing authorities an amount equal to a percentage of this compensation income at the time of exercise.

14.3. Disposition of Shares. The following tax consequences may apply upon disposition of the Shares.

(a) Incentive Stock Options. If the Shares are held for more than twelve (12) months after the date of purchase of the Shares pursuant to the exercise of an ISO and are disposed of more than two (2) years after the Date of Grant, any gain realized on disposition of the Shares will be treated as long term capital gain for federal income tax purposes. If Vested Shares purchased under an ISO are disposed of within the applicable one (1) year or two (2) year period, any gain realized on such disposition will be treated as compensation income (taxable at ordinary income rates in the year of the disposition) to the extent of the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price. To the extent the Shares were exercised prior to vesting coincident with the filing of an 83(b) Election, the amount taxed because of a disqualifying disposition will be based upon the excess, if any, of the fair market value on the date of vesting over the exercise price.

(b) Nonqualified Stock Options. If the Shares are held for more than twelve (12) months after the date of purchase of the Shares pursuant to the exercise of an NQSO, any gain realized on disposition of the Shares will be treated as long term capital gain.

14.4. Section 83(b) Election for Unvested Shares. With respect to Unvested Shares, which are subject to the Repurchase Option, unless an election is filed by Optionee with the Internal Revenue Service (and, if necessary, the proper state taxing authorities), within thirty (30) days of the purchase of the Unvested Shares, electing pursuant to Section 83(b) of the Code (and similar state tax provisions, if applicable) to be taxed currently on any difference between the Exercise Price of the Unvested Shares and their Fair Market Value on the date of purchase, there may be a recognition of taxable income (including, where applicable, alternative minimum taxable income) to Optionee, measured by the excess, if any, of the Fair Market Value of the Unvested Shares at the time they cease to be Unvested Shares, over the Exercise Price of the Unvested Shares.

15. GENERAL PROVISIONS.

15.1. Interpretation. Any dispute regarding the interpretation of this Agreement shall be submitted by Optionee or the Company to the Committee for review. The resolution of such a dispute by the Committee shall be final and binding on the Company and Optionee.

15.2. Entire Agreement. The Plan, the Grant Notice and the Exercise Agreement are each incorporated herein by reference. This Agreement, the Grant Notice, the Plan and the Exercise Agreement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede all prior undertakings and agreements with respect to such subject matter.

16. NOTICES. Any and all notices required or permitted to be given to a party pursuant to the provisions of this Agreement will be in writing and will be effective and deemed to provide such party sufficient notice under this Agreement on the earliest of the following: (i) at the time of personal delivery, if delivery is in person; (ii) at the time an electronic confirmation of receipt is received, if delivery is by email; (iii) at the time of transmission by facsimile, addressed to the other party at its facsimile number specified herein (or hereafter modified by subsequent notice to the parties hereto), with confirmation of

9

receipt made by both telephone and printed confirmation sheet verifying successful transmission of the facsimile; (iv) one (1) business day after deposit with an express overnight courier for United States deliveries, or two (2) business days after such deposit for deliveries outside of the United States, with proof of delivery from the courier requested; or (v) three (3) business days after deposit in the United States mail by certified mail (return receipt requested) for United States deliveries. Any notice for delivery outside the United States will be sent by email, facsimile or by express courier. Any notice not delivered personally or by email will be sent with postage and/or other charges prepaid and properly addressed to Optionee at the last known address or facsimile number on the books of the Company, or at such other address or facsimile number as such other party may designate by one of the indicated means of notice herein to the other parties hereto or, in the case of the Company, to it at its principal place of business. Notices to the Company will be marked “Attention: Chief Financial Officer.” Notices by facsimile shall be machine verified as received.

17. SUCCESSORS AND ASSIGNS. The Company may assign any of its rights under this Agreement including its rights to purchase Shares under both the Right of First Refusal and Repurchase Option. This Agreement shall be binding upon and inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer set forth herein, this Agreement shall be binding upon Optionee and Optionee’s heirs, executors, administrators, legal representatives, successors and assigns.

18. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the internal laws of the State of Delaware as such laws are applied to agreements between Delaware residents entered into and to be performed entirely within Delaware. If any provision of this Agreement is determined by a court of law to be illegal or unenforceable, then such provision will be enforced to the maximum extent possible and the other provisions will remain fully effective and enforceable.

19. FURTHER ASSURANCES. The parties agree to execute such further documents and instruments and to take such further actions as may be reasonably necessary to carry out the purposes and intent of this Agreement.

20. TITLES AND HEADINGS. The titles, captions and headings of this Agreement are included for ease of reference only and will be disregarded in interpreting or construing this Agreement. Unless otherwise specifically stated, all references herein to “sections” and “exhibits” will mean “sections” and “exhibits” to this Agreement.

21. COUNTERPARTS. This Agreement may be executed in any number of counterparts, each of which when so executed and delivered will be deemed an original, and all of which together shall constitute one and the same agreement.

22. SEVERABILITY. If any provision of this Agreement is determined by any court or arbitrator of competent jurisdiction to be invalid, illegal or unenforceable in any respect, such provision will be enforced to the maximum extent possible given the intent of the parties hereto. If such clause or provision cannot be so enforced, such provision shall be stricken from this Agreement and the remainder of this Agreement shall be enforced as if such invalid, illegal or unenforceable clause or provision had (to the extent not enforceable) never been contained in this Agreement. Notwithstanding the forgoing, if the value of this Agreement based upon the substantial benefit of the bargain for any party is materially impaired, which determination as made by the presiding court or arbitrator of competent jurisdiction shall be binding, then both parties agree to substitute such provision(s) through good faith negotiations.

* * * * *

Attachments: Annex A: Form of Stock Option Exercise Notice and Agreement

10

ANNEX A

FORM OF STOCK OPTION EXERCISE NOTICE AND AGREEMENT

EARLY EXERCISE FORM

STOCK OPTION EXERCISE NOTICE AND AGREEMENT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

*NOTE: You must sign this Notice on Page 3 before submitting it to Prelude Therapeutics Incorporated (the “Company”).

OPTIONEE INFORMATION: Please provide the following information about yourself (“Optionee”):

OPTION INFORMATION: Please provide this information on the option being exercised (the “Option”):

EXERCISE INFORMATION:

Number of shares of Common Stock of the Company for which the Option is now being exercised [________________]. (These shares are referred to below as the “Purchased Shares.”)

Total Exercise Price Being Paid for the Purchased Shares: $____________

Form of payment enclosed [check all that apply]:

AGREEMENTS, REPRESENTATIONS AND ACKNOWLEDGMENTS OF OPTIONEE:    By signing this Stock Option Exercise Notice and Agreement, Optionee hereby agrees with, and represents to, the Company as follows:

EARLY EXERCISE FORM

have not been registered under the Securities Act by reason of a specific exemption from such registration requirement and that the Purchased Shares must be held by me indefinitely, unless they are subsequently registered under the Securities Act or I obtain an opinion of counsel (in form and substance satisfactory to the Company and its counsel) that registration is not required. I acknowledge that the Company is under no obligation to register the Purchased Shares under the Securities Act or under any other securities law.

2

EARLY EXERCISE FORM

IMPORTANT NOTE: UNVESTED PURCHASED SHARES ARE SUBJECT TO REPURCHASE BY THE COMPANY. PLEASE CONSULT WITH YOUR TAX ADVISER CONCERNING THE ADVISABILITY OF FILING AN 83(b) ELECTION WITH THE INTERNAL REVENUE SERVICE WHICH MUST BE FILED WITHIN THIRTY (30) DAYS AFTER THE PURCHASE OF SHARES TO BE EFFECTIVE.

A form of Election under Section 83(b) is attached hereto as Exhibit 1 for reference. Unless an 83(b) election is timely filed with the Internal Revenue Service (and, if necessary, the proper state taxing authorities), electing pursuant to Section 83(b) of the Internal Revenue Code (and similar state tax provisions, if applicable) to be taxed currently on any difference between the purchase price of the Unvested Purchased Shares and their fair market value on the date of purchase, there may be a recognition of taxable income (including, where applicable, alternative minimum taxable income) to you, measured by the excess, if any, of the Fair Market Value of the Unvested Purchased Shares at the time they cease to be Unvested Purchased Shares, over the purchase price of the Unvested Purchased Shares.

The undersigned hereby executes and delivers this Stock Option Exercise Notice and Agreement and agrees to be bound by its terms

[Signature Page to Stock Option Exercise Notice and Agreement]

3

EARLY EXERCISE FORM

EXHIBIT 1

SECTION 83(b) ELECTION

ELECTION UNDER SECTION 83(b) OF THE

INTERNAL REVENUE CODE

The undersigned Taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended, to include the excess, if any, of the fair market value of the property described below at the time of transfer over the amount paid for such property, as compensation for services in the calculation of: (1) regular gross income; (2) alternative minimum taxable income; or (3) disqualifying disposition gross income, as the case may be.

THIS ELECTION MUST BE FILED WITH THE INTERNAL REVENUE SERVICE (“IRS”), AT THE OFFICE WHERE THE TAXPAYER FILES ANNUAL INCOME TAX RETURNS, WITHIN 30 DAYS AFTER THE DATE OF TRANSFER OF THE SHARES, AND MUST ALSO BE FILED WITH THE TAXPAYER’S INCOME TAX RETURNS FOR THE CALENDAR YEAR. THE ELECTION CANNOT BE REVOKED WITHOUT THE CONSENT OF THE IRS.

OPTION GRANT NO. ___

NOTICE OF STOCK OPTION GRANT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

The Optionee named below (“Optionee”) has been granted an option (this “Option”) to purchase shares of Common Stock, $0.0001 par value per share (the “Common Stock”), of Prelude Therapeutics Incorporated, a Delaware corporation (the “Company”), pursuant to the Company’s 2016 Stock Incentive Plan, as amended from time to time (the “Plan”) on the terms, and subject to the conditions, described below and in the Stock Option Agreement attached hereto as Exhibit A, including its annexes (the “Stock Option Agreement”).

Vesting Schedule [EXAMPLE ONLY]: For so long as Optionee continuously provides services to the Company (or any Subsidiary or Parent of the Company) as an employee, officer, director, contractor or consultant, this Option will vest (that is, become exercisable) with respect to the Shares as follows: (a) prior to the first one (1) year anniversary of the Vesting Start Date this Option will not be vested or exercisable as to any of the Shares; (b) this Option will become vested and exercisable with respect to [1/4^th] of the Shares on the one (1) year anniversary of the Vesting Start Date; and (c) thereafter, this Option will become vested and exercisable with respect to an additional [1/48^th] of the Shares when Optionee completes each month of continuous service following the first one (1) year anniversary of the Vesting Start Date.

General; Agreement: By their signatures below, Optionee and the Company agree that this Option is granted under and governed by this Notice of Stock Option Grant (this “Grant Notice”) and by the provisions of the Plan and the Stock Option Agreement. The Plan and the Stock Option Agreement are incorporated herein by reference. Capitalized terms used but not defined herein shall have the meanings given to them in the Plan or in the Stock Option Agreement, as applicable. By signing below, Optionee acknowledges receipt of a copy of this Grant Notice, the Plan and the Stock Option Agreement, represents that Optionee has carefully read and is familiar with their provisions, and hereby accepts the Option subject to all of their respective terms and conditions. Optionee acknowledges that there may be adverse tax consequences upon exercise of the Option or disposition of the Shares and that Optionee should consult a tax adviser prior to such exercise or disposition. Optionee agrees and acknowledges that the Vesting Schedule may change prospectively in the event that Optionee’s service status changes between full and part time status in accordance with Company policies relating to work schedules and vesting of equity awards.

Execution and Delivery: This Grant Notice may be executed and delivered electronically whether via the Company’s intranet or the Internet site of a third party or via email or any other means of electronic delivery specified by the Company. By Optionee’s acceptance hereof (whether written, electronic or otherwise), Optionee agrees, to the fullest extent permitted by law, that in lieu of receiving documents in paper format, Optionee accepts the electronic delivery of any documents that the Company (or any third party the Company may designate), may deliver in connection with this grant (including the Plan, this Grant Notice, the Stock Option Agreement, the information described in Rules 701(e)(2), (3), (4) and (5) under the Securities Act (the “701 Disclosures”), account statements, or other communications or information) whether via the Company’s intranet or the Internet site of such third party or via email or such other means of electronic delivery specified by the Company.

Exhibit A

Stock Option Agreement

EXHIBIT A

STOCK OPTION AGREEMENT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

This Stock Option Agreement (this “Agreement”) is made and entered into as of the date of grant (the “Date of Grant”) set forth on the Notice of Stock Option Grant attached as the facing page to this Agreement (the “Grant Notice”) by and between Prelude Therapeutics Incorporated, a Delaware corporation (the “Company”), and the optionee named on the Grant Notice (“Optionee”). Capitalized terms not defined in this Agreement shall have the meaning ascribed to them in the Company’s 2016 Stock Incentive Plan, as amended from time to time (the “Plan”), or in the Grant Notice, as applicable.

1. GRANT OF OPTION. The Company hereby grants to Optionee an option (this “Option”) to purchase up to the total number of shares of Common Stock of the Company, $0.0001 par value per share (the “Common Stock”), set forth in the Grant Notice as the Shares (the “Shares”) at the Exercise Price Per Share set forth in the Grant Notice (the “Exercise Price”), subject to all of the terms and conditions of the Grant Notice, this Agreement and the Plan. If designated as an Incentive Stock Option in the Grant Notice, this Option is intended to qualify as an incentive stock option (the “ISO”) within the meaning of Section 422 of the Internal Revenue Code of 1986, as amended (the “Code”), except that if on the Date of Grant Optionee is not subject to U.S. income tax, then this Option shall be a NQSO.

2. EXERCISE PERIOD.

2.1 Exercise Period of Option. This Option is considered to be “vested” with respect to any particular Shares when this Option is exercisable with respect to such Shares. This Option will become vested during its term as to portions of the Shares in accordance with the Vesting Schedule set forth in the Grant Notice. Notwithstanding any provision in the Plan or this Agreement to the contrary, on or after Optionee’s Termination Date, this Option may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date.

2.2 Vesting of Option Shares. Shares with respect to which this Option is vested and exercisable at a given time pursuant to the Vesting Schedule set forth in the Grant Notice are “Vested Shares.” Shares with respect to which this Option is not vested and exercisable at a given time pursuant to the Vesting Schedule set forth in the Grant Notice are “Unvested Shares.”

2.3 Expiration. The Option shall expire on the Expiration Date set forth in the Grant Notice or earlier as provided in Section 3 below.

3. TERMINATION.

3.1 Termination for Any Reason Except Death, Disability or Cause. Except as provided in subsection 3.2 in a case in which Optionee dies within three (3) months after Optionee is Terminated other than for Cause, if Optionee is Terminated for any reason (other than Optionee’s death or Disability or for Cause), then (a) on and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date and (b) this Option to the extent that it is exercisable with respect to Vested Shares on Optionee’s Termination Date, may be exercised by Optionee no later than three (3) months after Optionee’s Termination Date (but in no event may this Option be exercised after the Expiration Date).

3.2 Termination Because of Death or Disability. If Optionee is Terminated because of Optionee’s death or Disability (or if Optionee dies within three (3) months of the date of Optionee’s Termination for any reason other than for Cause), then (a) on and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date and (b) this Option, to the extent that it is exercisable with respect to Vested Shares on Optionee’s Termination Date, may be exercised by Optionee (or Optionee’s legal representative) no later than twelve (12) months after Optionee’s Termination Date, but in no event later than the Expiration Date. Any exercise of this Option beyond (i) three (3) months after the date Optionee ceases to be an employee when Optionee’s Termination is for any reason other than Optionee’s death or disability, within the meaning of Section 22(e)(3) of the Code; or (ii) twelve (12) months after the date Optionee ceases to be an employee when the termination is for Optionee’s disability, within the meaning of Section 22(e)(3) of the Code, is deemed to be an NQSO.

3.3 Termination for Cause. If Optionee is Terminated for Cause, then Optionee may exercise this Option, but only with respect to any Shares that are Vested Shares on Optionee’s Termination Date, and this Option shall expire on Optionee’s Termination Date, or at such later time and on such conditions as may be affirmatively determined by the Committee. On and after Optionee’s Termination Date, this Option shall expire immediately with respect to any Shares that are Unvested Shares and may not be exercised with respect to any Shares that are Unvested Shares on Optionee’s Termination Date.

3.4 No Obligation to Employ. Nothing in the Plan or this Agreement shall confer on Optionee any right to continue in the employ of, or other relationship with, the Company or any Parent or Subsidiary of the Company, or limit in any way the right of the Company or any Parent or Subsidiary of the Company to terminate Optionee’s employment or other relationship at any time, with or without Cause.

4. MANNER OF EXERCISE.

4.1 Stock Option Exercise Notice and Agreement. To exercise this Option, Optionee (or in the case of exercise after Optionee’s death or incapacity, Optionee’s executor, administrator, heir or legatee, as the case may be) must deliver to the Company an executed Stock Option Exercise Notice and Agreement in the form attached hereto as Annex A, or in such other form as may be approved by the Committee from time to time (the “Exercise Agreement”) and payment for the shares being purchased in accordance with this Agreement. The Exercise Agreement shall set forth, among other things, (i) Optionee’s election to exercise this Option, (ii) the number of Shares being purchased, (iii) any representations, warranties and agreements regarding Optionee’s investment intent and access to information as may be required by the Company to comply with applicable securities laws in connection with any exercise of this Option and (iv) any other agreements required by the Company. If someone other than Optionee exercises this Option, then such person must submit documentation reasonably acceptable to the Company verifying that such person has the legal right to exercise this Option and such person shall be subject to all of the restrictions contained herein as if such person were Optionee.

4.2 Limitations on Exercise. This Option may not be exercised unless such exercise is in compliance with all applicable federal and state securities laws, as they are in effect on the date of exercise.

4.3 Payment. The Exercise Agreement shall be accompanied by full payment of the Exercise Price for the shares being purchased in cash (by check, Automated Clearing House (“ACH”) or wire transfer), or where permitted by law:

(a) by cancellation of indebtedness of the Company owed to Optionee;

(b) by surrender of shares of the Company that are free and clear of all security interests, pledges, liens, claims or encumbrances and: (i) for which the Company has received “full payment of the purchase price” within the meaning of SEC Rule 144 (and, if such shares were purchased from the Company by use of a promissory note, such note has been fully paid with respect to such shares) or (ii) that were obtained by Optionee in the public market;

3

(c) by participating in a formal cashless exercise program implemented by the Committee in connection with the Plan;

(d) provided that a public market for the Common Stock exists and subject to compliance with applicable law, by exercising as set forth below, through a “same day sale” commitment from Optionee and a broker-dealer whereby Optionee irrevocably elects to exercise this Option and to sell a portion of the Shares so purchased sufficient to pay the total Exercise Price, and whereby the broker-dealer irrevocably commits upon receipt of such Shares to forward the total Exercise Price directly to the Company; or

(e) by any combination of the foregoing or any other method of payment approved by the Committee that constitutes legal consideration for the issuance of Shares.

For avoidance of uncertainty: ACH transfers that have been received by the Company into its bank account designated for receipt of such transfers shall be deemed to have been received for all purposes of this Option as of the date on which such transfers were initiated from the Optionee’s account and made irrevocable by Optionee.

4.4 Tax Withholding. Prior to the issuance of the Shares upon exercise of the Option, Optionee must pay or provide for foreign, federal, state and local income tax, social insurance, payroll tax, fringe benefits tax, payment on account withholding and other tax-related items related to Optionee’s participation in the Plan and legally applicable to Optionee, including, as applicable, obligations of the Company (all the foregoing tax-related items, “Tax-Related Items”). If the Committee permits, Optionee may provide for payment of withholding taxes upon exercise of the Option by requesting that the Company retain the number of Shares with a Fair Market Value equal to the amount of taxes required to be withheld; or to arrange a mandatory “sell to cover” on Optionee’s behalf (without further authorization); but in no event will the Company withhold Shares or “sell to cover” if such withholding would result in adverse accounting consequences to the Company. In case of stock withholding or a sell to cover, the Company shall issue the net number of Shares to Optionee by deducting the Shares retained from the Shares issuable upon exercise. The Company may withhold or account for Tax-Related Items by considering applicable minimum statutory withholding rates or other applicable statutory rates in Optionee’s country, including maximum applicable rates.

4.5 Issuance of Shares. Provided that the Exercise Agreement and payment are in form and substance satisfactory to counsel for the Company, the Company shall issue the Shares issuable upon a valid exercise of this Option registered in the name of Optionee, Optionee’s authorized assignee, or Optionee’s legal representative, and shall deliver certificates representing the Shares with the appropriate legends affixed thereto.

5. COMPLIANCE WITH LAWS AND REGULATIONS. The Plan and this Agreement are intended to comply with Rule 701. Any provision of this Agreement that is inconsistent with Rule 701 shall, without further act or amendment by the Company or the Committee, be reformed to comply with the requirements of Rule 701. The exercise of this Option and the issuance and transfer of Shares shall be subject to compliance by the Company and Optionee with all applicable requirements of federal and state securities laws and with all applicable requirements of any stock exchange on which the Common Stock may be listed at the time of such issuance or transfer. Optionee understands that the Company is under no obligation to register or qualify the Shares with the SEC, any state securities commission or any stock exchange to effect such compliance.

6. NONTRANSFERABILITY OF OPTION. This Option may not be transferred in any manner other than by will or by the laws of descent and distribution, and, with respect to NQSOs, by instrument to a testamentary trust in which the options are to be passed to beneficiaries upon the death of the trustor (settlor) or a revocable trust, or by gift to “immediate family” as that term is defined in 17 C.F.R. 240.16a-1(e), and may be exercised during the lifetime of Optionee only by Optionee or in the event of Optionee’s incapacity, by Optionee’s legal representative. The terms of this Option shall be binding upon the executors, administrators, successors and assigns of Optionee.

4

7. RESTRICTIONS ON TRANSFER.

7.1 Disposition of Shares. Optionee hereby agrees that Optionee shall make no disposition of any of the Shares (other than as permitted by this Agreement) unless and until:

(a) Optionee shall have notified the Company of the proposed disposition and provided a written summary of the terms and conditions of the proposed disposition;

(b) Optionee shall have complied with all requirements of this Agreement applicable to the disposition of the Shares;

(c) Optionee shall have provided the Company with written assurances, in form and substance satisfactory to counsel for the Company, that (i) the proposed disposition does not require registration of the Shares under the Securities Act or under any applicable state securities laws or (ii) all appropriate actions necessary for compliance with the registration requirements of the Securities Act or of any exemption from registration available under the Securities Act (including Rule 144) or applicable state securities laws have been taken; and

(d) Optionee shall have provided the Company with written assurances, in form and substance satisfactory to the Company, that the proposed disposition will not result in the contravention of any transfer restrictions applicable to the Shares pursuant to the provisions of the regulations promulgated under Rule 701 or under any other applicable securities laws or adversely affect the Company’s ability to rely on the exemption(s) from registration under the Securities Act or under any other applicable securities laws for the grant of the Option, the issuance of Shares thereunder or any other issuance of securities under the Plan.

7.2 Restriction on Transfer. Optionee shall not transfer, assign, grant a lien or security interest in, pledge, hypothecate, encumber or otherwise dispose of any of the Shares which are subject to the Company’s Right of First Refusal described below, except as permitted by this Agreement.

7.3 Transferee Obligations. Each person (other than the Company) to whom the Shares are transferred by means of one of the permitted transfers specified in this Agreement must, as a condition precedent to the validity of such transfer, acknowledge in writing to the Company that such person is bound by the provisions of this Agreement and that the transferred Shares are subject to (i) the Company’s Right of First Refusal granted hereunder and (ii) the market stand-off provisions of Section 8 below, to the same extent such Shares would be so subject if retained by Optionee.

8. MARKET STANDOFF AGREEMENT. Optionee agrees that, subject to any early release provisions that apply pro rata to stockholders of the Company according to their holdings of Common Stock (determined on an as-converted into Common Stock basis), Optionee will not, for a period of up to one hundred eighty (180) days (plus up to an additional thirty five (35) days to the extent reasonably requested by the Company or such underwriter(s) to accommodate regulatory restrictions on the publication or other distribution of research reports or earnings releases by the Company, including NASD and NYSE rules) following the effective date of the registration statement filed with the SEC relating to the initial underwritten sale of Common Stock of the Company to the public under the Securities Act (the “IPO”), directly or indirectly sell, offer to sell, grant any option for the sale of, or otherwise dispose of any Common Stock or securities convertible into Common Stock, except for: (i) transfers of Shares permitted under Section 9.6 hereof so long as such transferee furnishes to the Company and the managing underwriter their written consent to be bound by this Section 8 as a condition precedent to such transfer; and (ii) sales of any securities to be included in the registration statement for the IPO. For the avoidance of doubt, the provisions

5

of this Section shall only apply to the IPO. The restricted period shall in any event terminate two (2) years after the closing date of the IPO. In order to enforce the foregoing covenant, the Company shall have the right to place restrictive legends on the certificates representing the Shares subject to this Section and to impose stop transfer instructions with respect to the Shares until the end of such period. Optionee further agrees to enter into any agreement reasonably required by the underwriters to implement the foregoing restrictions on transfer. For the avoidance of doubt, the foregoing provisions of this Section shall not apply to any registration of securities of the Company (a) under an employee benefit plan or (b) in a merger, consolidation, business combination or similar transaction.

9. COMPANY’S RIGHT OF FIRST REFUSAL. Before any Shares held by Optionee or any transferee of such Shares (either sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including, without limitation, a transfer by gift or operation of law), the Company and/or its assignee(s) will have a right of first refusal to purchase the Shares to be sold or transferred (the “Offered Shares”) on the terms and conditions set forth in this Section (the “Right of First Refusal”).

9.1 Notice of Proposed Transfer. The Holder of the Offered Shares will deliver to the Company a written notice (the “Notice”) stating: (i) the Holder’s bona fide intention to sell or otherwise transfer the Offered Shares; (ii) the name and address of each proposed purchaser or other transferee (the “Proposed Transferee”); (iii) the number of Offered Shares to be transferred to each Proposed Transferee; (iv) the bona fide cash price or other consideration for which the Holder proposes to transfer the Offered Shares (the “Offered Price”); and (v) that the Holder acknowledges this Notice is an offer to sell the Offered Shares to the Company and/or its assignee(s) pursuant to the Company’s Right of First Refusal at the Offered Price as provided for in this Agreement.

9.2 Exercise of Right of First Refusal. At any time within thirty (30) days after the date of the Notice, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all (or, with the consent of the Holder, less than all) the Offered Shares proposed to be transferred to any one or more of the Proposed Transferees named in the Notice, at the purchase price, determined as specified below.

9.3 Purchase Price. The purchase price for the Offered Shares purchased under this Section will be the Offered Price, provided that if the Offered Price consists of no legal consideration (as, for example, in the case of a transfer by gift) then the purchase price will be the fair market value of the Offered Shares as determined in good faith by the Committee. If the Offered Price includes consideration other than cash, then the value of the non-cash consideration, as determined in good faith by the Committee, will conclusively be deemed to be the cash equivalent value of such non-cash consideration.

9.4 Payment. Payment of the purchase price for the Offered Shares will be payable, at the option of the Company and/or its assignee(s) (as applicable), by check or by cancellation of all or a portion of any outstanding purchase money indebtedness owed by the Holder to the Company (or to such assignee, in the case of a purchase of Offered Shares by such assignee) or by any combination thereof. The purchase price will be paid without interest within sixty (60) days after the Company’s receipt of the Notice, or, at the option of the Company and/or its assignee(s), in the manner and at the time(s) set forth in the Notice.

9.5 Holder’s Right to Transfer. If all of the Offered Shares proposed in the Notice to be transferred to a given Proposed Transferee are not purchased by the Company and/or its assignee(s) as provided in this Section, then the Holder may sell or otherwise transfer such Offered Shares to each Proposed Transferee at the Offered Price or at a higher price, provided that (i) such sale or other transfer is consummated within ninety (90) days after the date of the Notice, (ii) any such sale or other transfer is effected in compliance with all applicable securities laws, and (iii) each Proposed Transferee agrees in writing that the provisions of this Section will continue to apply to the Offered Shares in the hands of such Proposed Transferee. If the Offered Shares described in the Notice are not transferred to each Proposed Transferee within such ninety (90) day period, then a new Notice must be given to the Company pursuant to which the Company will again be offered the Right of First Refusal before any Shares held by the Holder may be sold or otherwise transferred.

6

9.6 Exempt Transfers. Notwithstanding anything to the contrary in this Section, the following transfers of Shares will be exempt from the Right of First Refusal: (i) the transfer of any or all of the Shares during Optionee’s lifetime by gift or on Optionee’s death by will or intestacy to any member(s) of Optionee’s “Immediate Family” (as defined below) or to a trust for the benefit of Optionee and/or member(s) of Optionee’s Immediate Family, provided that each transferee or other recipient agrees in a writing satisfactory to the Company that the provisions of this Section will continue to apply to the transferred Shares in the hands of such transferee or other recipient; (ii) any transfer of Shares made pursuant to a statutory merger, statutory consolidation of the Company with or into another corporation or corporations or a conversion of the Company into another form of legal entity (except that the Right of First Refusal will continue to apply thereafter to such Shares, in which case the surviving corporation of such merger or consolidation or the resulting entity of such conversion shall succeed to the rights of the Company under this Section unless the agreement of merger or consolidation or conversion expressly otherwise provides); or (iii) any transfer of Shares pursuant to the winding up and dissolution of the Company. As used herein, the term “Immediate Family” will mean Optionee’s spouse, the lineal descendant or antecedent, father, mother, brother or sister, child, adopted child, grandchild or adopted grandchild of Optionee or Optionee’s spouse, or the spouse of any of the above or Spousal Equivalent, as defined herein. As used herein, a person is deemed to be a “Spousal Equivalent” provided the following circumstances are true: (i) irrespective of whether or not Optionee and the Spousal Equivalent are the same sex, they are the sole spousal equivalent of the other for the last twelve (12) months, (ii) they intend to remain so indefinitely, (iii) neither are married to anyone else, (iv) both are at least 18 years of age and mentally competent to consent to contract, (v) they are not related by blood to a degree of closeness that which would prohibit legal marriage in the state in which they legally reside, (vi) they are jointly responsible for each other’s common welfare and financial obligations, and (vii) they reside together in the same residence for the last twelve (12) months and intend to do so indefinitely.

9.7 Termination of Right of First Refusal. The Right of First Refusal will terminate as to all Shares: (i) on the effective date of the first sale of Common Stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the SEC under the Securities Act (other than a registration statement relating solely to the issuance of Common Stock pursuant to a business combination or an employee incentive or benefit plan); (ii) on any transfer or conversion of Shares made pursuant to a statutory merger or statutory consolidation of the Company with or into another corporation or corporations if the common stock of the surviving corporation or any direct or indirect parent corporation thereof is registered under the Exchange Act; or (iii) on any transfer or conversion of Shares made pursuant to a statutory conversion of the Company into another form of legal entity if the common equity (or comparable equity security) of entity resulting from such conversion is registered under the Exchange Act.

9.8 Encumbrances on Shares. Optionee may grant a lien or security interest in, or pledge, hypothecate or encumber Shares only if each party to whom such lien or security interest is granted, or to whom such pledge, hypothecation or other encumbrance is made, agrees in a writing satisfactory to the Company that: (i) such lien, security interest, pledge, hypothecation or encumbrance will not adversely affect or impair the Right of First Refusal or the rights of the Company and/or its assignee(s) with respect thereto and will not apply to such Shares after they are acquired by the Company and/or its assignees under this Section; and (ii) the provisions of this Agreement will continue to apply to such Shares in the hands of such party and any transferee of such party.

10. RIGHTS AS A STOCKHOLDER. Optionee shall not have any of the rights of a stockholder with respect to any Shares unless and until such Shares are issued to Optionee. Subject to the terms and conditions of this Agreement, Optionee will have all of the rights of a stockholder of the Company with respect to the Shares from and after the date that Shares are issued to Optionee pursuant to, and in accordance with, the terms of the Exercise Agreement until such time as Optionee disposes of the Shares

7

or the Company and/or its assignee(s) exercise(s) the Right of First Refusal. Upon an exercise of the Right of First Refusal, Optionee will have no further rights as a holder of the Shares so purchased upon such exercise, other than the right to receive payment for the Shares so purchased in accordance with the provisions of this Agreement, and Optionee will promptly surrender the stock certificate(s) evidencing the Shares so purchased to the Company for transfer or cancellation.

11. ESCROW. As security for Optionee’s faithful performance of this Agreement, Optionee agrees, immediately upon receipt of the stock certificate(s) evidencing the Shares, to deliver such certificate(s) to the Secretary of the Company or other designee of the Company (the “Escrow Holder”), who is hereby appointed to hold such certificate(s) in escrow and to take all such actions and to effectuate all such transfers and/or releases of such Shares as are in accordance with the terms of this Agreement. Optionee and the Company agree that Escrow Holder will not be liable to any party to this Agreement (or to any other party) for any actions or omissions unless Escrow Holder is grossly negligent or intentionally fraudulent in carrying out the duties of Escrow Holder under this Agreement. Escrow Holder may rely upon any letter, notice or other document executed with any signature purported to be genuine and may rely on the advice of counsel and obey any order of any court with respect to the transactions contemplated by this Agreement and will not be liable for any act or omission taken by Escrow Holder in good faith reliance on such documents, the advice of counsel or a court order. The Shares will be released from escrow upon termination of the Right of First Refusal.

12. RESTRICTIVE LEGENDS AND STOP-TRANSFER ORDERS.

12.1 Legends. Optionee understands and agrees that the Company will place the legends set forth below or similar legends on any stock certificate(s) evidencing the Shares, together with any other legends that may be required by state or U.S. Federal securities laws, the Company’s Certificate of Incorporation or Bylaws, any other agreement between Optionee and the Company, or any agreement between Optionee and any third party (and any other legend(s) that the Company may become obligated to place on the stock certificate(s) evidencing the Shares under the terms of any agreement to which the Company is or may become bound or obligated):

(a) THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR UNDER THE SECURITIES LAWS OF CERTAIN STATES. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. INVESTORS SHOULD BE AWARE THAT THEY MAY BE REQUIRED TO BEAR THE FINANCIAL RISKS OF THIS INVESTMENT FOR AN INDEFINITE PERIOD OF TIME. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

(b) THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON RESALE AND TRANSFER, INCLUDING THE RIGHT OF FIRST REFUSAL HELD BY THE ISSUER AND/OR ITS ASSIGNEE(S) AS SET FORTH IN A STOCK OPTION AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH SALE AND TRANSFER RESTRICTIONS, INCLUDING THE RIGHT OF FIRST REFUSAL, ARE BINDING ON TRANSFEREES OF THESE SHARES.

8

(c) THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A MARKET STANDOFF RESTRICTION AS SET FORTH IN A CERTAIN STOCK OPTION AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. AS A RESULT OF SUCH AGREEMENT, THESE SHARES MAY NOT BE TRADED PRIOR TO 180 DAYS AFTER THE EFFECTIVE DATE OF CERTAIN PUBLIC OFFERINGS OF THE COMMON STOCK OF THE ISSUER HEREOF. SUCH RESTRICTION IS BINDING ON TRANSFEREES OF THESE SHARES.

12.2 Stop-Transfer Instructions. Optionee agrees that, to ensure compliance with the restrictions imposed by this Agreement, the Company may issue appropriate “stop-transfer” instructions to its transfer agent, if any, and if the Company transfers its own securities, it may make appropriate notations to the same effect in its own records.

12.3 Refusal to Transfer. The Company will not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares, or to accord the right to vote or pay dividends to any purchaser or other transferee to whom such Shares have been so transferred.

13. CERTAIN TAX CONSEQUENCES. Set forth below is a brief summary as of the Effective Date of the Plan of some of the federal tax consequences of exercise of the Option and disposition of the Shares. THIS SUMMARY IS NECESSARILY INCOMPLETE, AND THE TAX LAWS AND REGULATIONS ARE SUBJECT TO CHANGE. OPTIONEE SHOULD CONSULT A TAX ADVISER BEFORE EXERCISING THE OPTION OR DISPOSING OF THE SHARES.

13.1 Exercise of ISO. If the Option qualifies as an ISO, there will be no regular federal income tax liability upon the exercise of the Option, although the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price will be treated as a tax preference item for federal alternative minimum tax purposes and may subject Optionee to the alternative minimum tax in the year of exercise.

13.2 Exercise of Nonqualified Stock Option. If the Option does not qualify as an ISO, there may be a regular federal income tax liability upon the exercise of the Option. Optionee will be treated as having received compensation income (taxable at ordinary income tax rates) equal to the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price. If Optionee is a current or former employee of the Company, the Company may be required to withhold from Optionee’s compensation or collect from Optionee and pay to the applicable taxing authorities an amount equal to a percentage of this compensation income at the time of exercise.

13.3 Disposition of Shares. The following tax consequences may apply upon disposition of the Shares.

(a) Incentive Stock Options. If the Shares are held for more than twelve (12) months after the date of purchase of the Shares pursuant to the exercise of an ISO and are disposed of more than two (2) years after the Date of Grant, any gain realized on disposition of the Shares will be treated as long term capital gain for federal income tax purposes. If Shares purchased under an ISO are disposed of within the applicable one (1) year or two (2) year period, any gain realized on such disposition will be treated as compensation income (taxable at ordinary income rates in the year of the disposition) to the extent of the excess, if any, of the Fair Market Value of the Shares on the date of exercise over the Exercise Price.

(b) Nonqualified Stock Options. If the Shares are held for more than twelve (12) months after the date of purchase of the Shares pursuant to the exercise of an NQSO, any gain realized on disposition of the Shares will be treated as long term capital gain.

9

14. GENERAL PROVISIONS.

14.1 Interpretation. Any dispute regarding the interpretation of this Agreement shall be submitted by Optionee or the Company to the Committee for review. The resolution of such a dispute by the Committee shall be final and binding on the Company and Optionee.

14.2 Entire Agreement. The Plan, the Grant Notice and the Exercise Agreement are each incorporated herein by reference. This Agreement, the Grant Notice, the Plan and the Exercise Agreement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede all prior undertakings and agreements with respect to such subject matter.

15. NOTICES. Any and all notices required or permitted to be given to a party pursuant to the provisions of this Agreement will be in writing and will be effective and deemed to provide such party sufficient notice under this Agreement on the earliest of the following: (i) at the time of personal delivery, if delivery is in person; (ii) at the time an electronic confirmation of receipt is received, if delivery is by email; (iii) at the time of transmission by facsimile, addressed to the other party at its facsimile number specified herein (or hereafter modified by subsequent notice to the parties hereto), with confirmation of receipt made by both telephone and printed confirmation sheet verifying successful transmission of the facsimile; (iv) one (1) business day after deposit with an express overnight courier for United States deliveries, or two (2) business days after such deposit for deliveries outside of the United States, with proof of delivery from the courier requested; or (v) three (3) business days after deposit in the United States mail by certified mail (return receipt requested) for United States deliveries. Any notice for delivery outside the United States will be sent by email, facsimile or by express courier. Any notice not delivered personally or by email will be sent with postage and/or other charges prepaid and properly addressed to Optionee at the last known address or facsimile number on the books of the Company, or at such other address or facsimile number as such other party may designate by one of the indicated means of notice herein to the other parties hereto or, in the case of the Company, to it at its principal place of business. Notices to the Company will be marked “Attention: Chief Financial Officer.” Notices by facsimile shall be machine verified as received.

16. SUCCESSORS AND ASSIGNS. The Company may assign any of its rights under this Agreement including its rights to purchase Shares under the Right of First Refusal. This Agreement shall be binding upon and inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer set forth herein, this Agreement shall be binding upon Optionee and Optionee’s heirs, executors, administrators, legal representatives, successors and assigns.

17. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the internal laws of the State of Delaware as such laws are applied to agreements between Delaware residents entered into and to be performed entirely within Delaware. If any provision of this Agreement is determined by a court of law to be illegal or unenforceable, then such provision will be enforced to the maximum extent possible and the other provisions will remain fully effective and enforceable.

18. FURTHER ASSURANCES. The parties agree to execute such further documents and instruments and to take such further actions as may be reasonably necessary to carry out the purposes and intent of this Agreement.

19. TITLES AND HEADINGS. The titles, captions and headings of this Agreement are included for ease of reference only and will be disregarded in interpreting or construing this Agreement. Unless otherwise specifically stated, all references herein to “sections” and “exhibits” will mean “sections” and “exhibits” to this Agreement.

20. COUNTERPARTS. This Agreement may be executed in any number of counterparts, each of which when so executed and delivered will be deemed an original, and all of which together shall constitute one and the same agreement.

10

21. SEVERABILITY. If any provision of this Agreement is determined by any court or arbitrator of competent jurisdiction to be invalid, illegal or unenforceable in any respect, such provision will be enforced to the maximum extent possible given the intent of the parties hereto. If such clause or provision cannot be so enforced, such provision shall be stricken from this Agreement and the remainder of this Agreement shall be enforced as if such invalid, illegal or unenforceable clause or provision had (to the extent not enforceable) never been contained in this Agreement. Notwithstanding the forgoing, if the value of this Agreement based upon the substantial benefit of the bargain for any party is materially impaired, which determination as made by the presiding court or arbitrator of competent jurisdiction shall be binding, then both parties agree to substitute such provision(s) through good faith negotiations.

* * * * *

Attachment: Annex A: Form of Stock Option Exercise Notice and Agreement

11

ANNEX A

FORM OF STOCK OPTION EXERCISE NOTICE AND AGREEMENT

STOCK OPTION EXERCISE NOTICE AND AGREEMENT

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

*NOTE: You must sign this Notice on Page 3 before submitting it to Prelude Therapeutics Incorporated (the “Company”).

OPTIONEE INFORMATION: Please provide the following information about yourself (“Optionee”):

OPTION INFORMATION: Please provide this information on the option being exercised (the “Option”):

EXERCISE INFORMATION:

Number of shares of Common Stock of the Company for which the Option is now being exercised [________________]. (These shares are referred to below as the “Purchased Shares.”)

Total Exercise Price Being Paid for the Purchased Shares: $____________

Form of payment enclosed [check all that apply]:

AGREEMENTS, REPRESENTATIONS AND ACKNOWLEDGMENTS OF OPTIONEE: By signing this Stock Option Exercise Notice and Agreement, Optionee hereby agrees with, and represents to, the Company as follows:

have not been registered under the Securities Act by reason of a specific exemption from such registration requirement and that the Purchased Shares must be held by me indefinitely, unless they are subsequently registered under the Securities Act or I obtain an opinion of counsel (in form and substance satisfactory to the Company and its counsel) that registration is not required. I acknowledge that the Company is under no obligation to register the Purchased Shares under the Securities Act or under any other securities law.

2

The undersigned hereby executes and delivers this Stock Option Exercise Notice and Agreement and agrees to be bound by its terms

[Signature Page to Stock Option Exercise Notice and Agreement]

3

PRELUDE THERAPEUTICS INCORPORATED

2016 STOCK INCENTIVE PLAN

RESTRICTED STOCK PURCHASE AGREEMENT

This Restricted Stock Purchase Agreement (the “Agreement”) is made and entered into as of _________________ (the “Effective Date”) by and between Prelude Therapeutics Incorporated, a Delaware corporation (the “Company”), and _____________ (“Purchaser”). Capitalized terms not defined herein shall have the meanings ascribed to them in the Company’s 2016 Stock Incentive Plan, as may be amended from time to time (the “Plan”).

1. PURCHASE OF SHARES.

1.1 Agreement to Purchase and Sell Shares. On the Effective Date and subject to the terms and conditions of this Agreement and the Plan, Purchaser hereby purchases from the Company, and the Company hereby sells to Purchaser, _____________ (_______) shares of the Company’s Common Stock (the “Shares”), at the price of ___________($____) per share (the “Purchase Price Per Share”) for a Total Purchase Price of ___________($________) (the “Purchase Price”). As used in this Agreement, the term “Shares” includes the Shares purchased under this Agreement and all securities received (a) in replacement of the Shares, (b) as a result of stock dividends or stock splits with respect to the Shares, and (c) in replacement of the Shares in a merger, recapitalization, reorganization or similar corporate transaction.

1.2 Payment. Purchaser hereby delivers payment of the Purchase Price as follows (check and complete as appropriate):

For avoidance of uncertainty: ACH transfers that have been successfully received by the Company into its bank account designated for receipt of such transfers shall be deemed to have been received for all purposes of this Agreement as of the date on which such transfers were initiated from the Purchaser’s account and made irrevocable by Purchaser.

2. DELIVERIES.

2.1 Deliveries by the Purchaser. Purchaser hereby delivers to the Company at its principal executive offices: (a) this completed and signed Agreement, and (b) the Purchase Price, paid by delivery of the form of payment specified in Section 1.2.

1

2.2 Deliveries by the Company. Upon its receipt of the Purchase Price, payment or other provision for any applicable tax obligations, if any, and all the documents to be executed and delivered by Purchaser to the Company as provided herein, the Company will issue a duly executed stock certificate evidencing the Shares in the name of Purchaser with the appropriate legends affixed thereto, to be placed in escrow as provided in Section 7.2 to secure performance of Purchaser’s obligations under Sections 5 and 6 until expiration or termination of the Company’s Repurchase Option and Refusal Right (as such terms are defined in Sections 5 and 6, respectively).

3. REPRESENTATIONS AND WARRANTIES OF PURCHASER. Purchaser represents and warrants to the Company as follows.

3.1 Agrees to Terms of the Plan. Purchaser has received a copy of the Plan, has read and understands the terms of the Plan and this Agreement, and agrees to be bound by their terms and conditions.

3.2 Acknowledgment of Tax Risks. Purchaser acknowledges that there may be adverse tax consequences upon the purchase and the disposition of the Shares, and that Purchaser has been advised by the Company to consult a tax adviser prior to such purchase or disposition. Purchaser further acknowledges that Purchaser is not relying on the Company or its counsel for tax advice regarding Purchaser’s purchaser or disposition of the Shares or the tax consequences to Purchaser of this Agreement.

3.3 Shares Not Registered or Qualified. Purchaser understands and acknowledges that the Shares have not been registered with the SEC under the Securities Act, or with any securities regulatory agency administering any state securities laws, and that, notwithstanding any other provision of this Agreement to the contrary, the purchase of any Shares is expressly conditioned upon compliance with the Securities Act and all applicable state securities laws. Purchaser agrees to cooperate with the Company to ensure compliance with such laws.

3.4 No Transfer Unless Registered or Exempt; Contractual Restrictions on Transfers. Purchaser understands that Purchaser may not transfer any Shares unless such Shares are registered under the Securities Act or qualified under applicable state securities laws or unless, in the opinion of counsel to the Company, exemptions from such registration and qualification requirements are available. Purchaser understands that only the Company may file a registration statement with the SEC and that the Company is under no obligation to do so with respect to the Shares. Purchaser has also been advised that exemptions from registration and qualification may not be available or may not permit Purchaser to transfer all or any of the Shares in the amounts or at the times proposed by Purchaser. Purchaser further acknowledges that this Agreement imposes additional restrictions on transfer of the Shares.

3.5 SEC Rule 701. Shares that are issued pursuant to SEC Rule 701 promulgated under the Securities Act may become freely tradable by non-affiliates (under limited conditions regarding the method of sale) ninety (90) days after the first sale of Common Stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the SEC, subject to the lengthier market standoff agreement contained in Section 4 of this Agreement or any other agreement entered into by Purchaser. Affiliates must comply with the provisions (other than the holding period requirements) of Rule 144 which permits certain limited sales of unregistered securities. Rule 144 is not presently available with respect to the Shares and, in any event, requires that the Shares be held for a minimum of six (6) months, and in certain cases one (1) year, after they have been purchased and paid for (within the meaning of Rule 144). Purchaser understands that use of a promissory note as payment for the Shares may not be deemed to be “full payment of the purchase price” within the meaning of Rule 144 unless certain conditions are met and that, accordingly, the Rule 144 holding period of such Shares may not begin to run until such Shares are fully paid for within the meaning of Rule 144. Purchaser understands that Rule 144 may indefinitely restrict transfer of the Shares so long as Purchaser remains an “affiliate” of the Company or if “current public information” about the Company (as defined in Rule 144) is not publicly available.

2

3.6 Access to Information. Purchaser has had access to all information regarding the Company and its present and prospective business, assets, liabilities and financial condition that Purchaser reasonably considers important in making the decision to purchase the Shares, and Purchaser has had ample opportunity to ask questions of the Company’s representatives concerning such matters and this investment.

3.7 Understanding of Risks. Purchaser is fully aware of: (a) the highly speculative nature of the investment in the Shares; (b) the financial hazards involved; (c) the lack of liquidity of the Shares and the restrictions on transferability of the Shares (e.g., that Purchaser may not be able to sell or dispose of the Shares or use them as collateral for loans); (d) the qualifications and backgrounds of the management of the Company; and (e) the tax consequences of investment in, and disposition of, the Shares.

3.8 Purchase for Own Account for Investment. Purchaser is purchasing the Shares for Purchaser’s own account for investment purposes only and not with a view to, or for sale in connection with, a distribution of the Shares within the meaning of the Securities Act. Purchaser has no present intention of selling or otherwise disposing of all or any portion of the Shares and no one other than Purchaser has any beneficial ownership of any of the Shares.

3.9 No General Solicitation. At no time was Purchaser presented with or solicited by any publicly issued or circulated newspaper, mail, radio, television or other form of general advertising or solicitation in connection with the offer, sale and purchase of the Shares.

3.10 SEC Rule 144. Purchaser has been advised that SEC Rule 144 promulgated under the Securities Act, which permits certain limited sales of unregistered securities, is not presently available with respect to the Shares and, in any event, requires that the Shares be held for a minimum of six (6) months, and in certain cases one (1) year, after they have been purchased and paid for (within the meaning of Rule 144), subject to the lengthier market standoff agreement contained in Section 4 of this Agreement or any other agreement entered into by Purchaser. Purchaser understands that Rule 144 may indefinitely restrict transfer of the Shares so long as Purchaser remains an “affiliate” of the Company or if “current public information” about the Company (as defined in Rule 144) is not publicly available.

4. MARKET STANDOFF AGREEMENT. Subject to the provisions of this Section, Purchaser agrees in connection with any registration of the Company’s securities under the Securities Act or other registered public offering that, Purchaser will not sell or otherwise dispose of any Shares without the prior written consent of the Company or such managing underwriters, as the case may be, for a period of time (not to exceed one hundred eighty (180) days) after the effective date of such registration requested by such managing underwriters and subject to all restrictions as the Company or the managing underwriters may specify for employee-stockholders generally; provided however, that if during the last seventeen (17) days of the restricted period the Company issues an earnings release or material news, or a material event relating to the Company occurs, or prior to the expiration of the restricted period the Company announces that it will release earnings results during the sixteen (16)-day period beginning on the last day of the restricted period, then, if required by the underwriters or the Company, for so long as, and to the extent that, Rule 2711 or any successor rule of the Financial Industry Regulatory Authority applies, the restrictions imposed by this Section 4 shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event. The restricted period shall in any event terminate two (2) years after the closing date of the Company’s initial public offering. For purposes of this Section 4, the term “Company” shall include any wholly-owned subsidiary of the Company into which the Company merges or consolidates. In order to enforce the foregoing covenant, the Company shall have the right to place restrictive legends on the certificates representing the shares subject to this Section and to impose stop transfer instructions with respect to the Shares until the end of such period. Purchaser further agrees that the underwriters of any such registered public offering shall be third party beneficiaries of this Section 4 and agrees to enter into any agreement reasonably required by the underwriters to implement the foregoing. Notwithstanding anything in this Section to the contrary, for the avoidance of doubt, the foregoing provisions of this Section shall not apply to any registration of securities of the Company (a) under an employee benefit plan or (b) in a merger, consolidation, business combination or similar transaction.

3

5. COMPANY’S REPURCHASE OPTION FOR UNVESTED SHARES. The Company, or (subject to Section 5.6) its assignee, shall have the option to repurchase all or a portion of the Purchaser’s Shares that are Unvested Shares (as defined below) on the Termination Date on the terms and conditions set forth in this Section (the “Repurchase Option”) if Purchaser is Terminated (as defined in the Plan) for any reason, or no reason, including without limitation, Purchaser’s death, Disability (as defined in the Plan), voluntary resignation or termination by the Company with or without Cause.

5.1 Termination and Termination Date. In case of any dispute as to whether Purchaser is Terminated, the Committee shall have discretion to determine in good faith whether Purchaser has been Terminated and the effective date of such Termination (the “Termination Date”).

5.2 Vested and Unvested Shares. Shares that are vested pursuant to the schedule set forth in this Section 5.2 are “Vested Shares.” Shares that are not vested pursuant to such schedule are “Unvested Shares.” On the Effective Date, ________________ of the Shares will be Unvested Shares (the “Initial Unvested Shares”). Provided Purchaser continues to provide services to the Company or any Subsidiary or Parent of the Company at all times from the Effective Date until ________________ (the “First Vesting Date”), then on the First Vesting Date one-fourth (1/4^th) of the Initial Unvested Shares will become Vested Shares, and on the same day of each succeeding calendar month thereafter (or if there is no such day in any month, then the last day of such calendar month), an additional one forty-eighth 1/48^th of the Initial Unvested Shares shall vest until the earliest to occur of (a) the date all of the Shares are Vested Shares, (b) the Termination Date or (c) the date vesting otherwise terminates pursuant to this Agreement or the Plan. No fractional Shares shall be issued. No Shares will become Vested Shares after the Termination Date. The number of the Shares that are Vested Shares or Unvested Shares will be proportionally adjusted to reflect any stock split, reverse stock split or similar change in the capital structure of the Company as set forth in Section 2.2 of the Plan occurring after the Effective Date.

5.3 Exercise of Repurchase Option. At any time within ninety (90) days after the Purchaser’s Termination Date, the Company, or its assignee, may, at its option, elect to repurchase any or all the Purchaser’s Shares that are Unvested Shares on the Termination Date by giving Purchaser written notice of exercise of the Repurchase Option, specifying the number of Unvested Shares to be repurchased. Such Unvested Shares shall be repurchased at the Purchase Price Per Share, proportionately adjusted for any stock split, reverse stock split or similar change in the capital structure of the Company as set forth in Section 2.2 of the Plan occurring after the Effective Date (the “Repurchase Price”). The Repurchase Price shall be payable, at the option of the Company or its assignee, by check or by cancellation of all or a portion of any outstanding indebtedness owed by Purchaser to the Company and/or such assignee, or by any combination thereof. The Repurchase Price shall be paid without interest within the term of the Repurchase Option as described in the first sentence of this Section 5.3. The Company may, at its option, decline to exercise its Repurchase Option or may exercise its Repurchase Option only with respect to a portion of the Unvested Shares.

5.4 Right of Termination Unaffected. Nothing in this Agreement shall be construed to limit or otherwise affect in any manner whatsoever the right or power of the Company (or any Parent or Subsidiary of the Company) to terminate Purchaser’s employment or other relationship with Company (or the Parent or Subsidiary of the Company) at any time, for any reason or no reason, with or without Cause.

5.5 Additional or Exchanged Securities and Property. Subject to the provisions of Section 5.2 above, in the event of a merger or consolidation of the Company with or into another entity, any other corporate reorganization, a stock split, the declaration of a stock dividend, the declaration of an extraordinary dividend payable in a form other than stock, a spin-off, a recapitalization or a similar transaction affecting the Company’s outstanding securities, any securities or other property (including cash or cash equivalents) that are by reason of such transaction exchanged for, or distributed or issued with

4

respect to, any Unvested Shares shall immediately be subject to the Repurchase Option. Appropriate adjustments shall be made to the price per share to be paid for Unvested Shares upon the exercise of the Repurchase Option (by allocating such price among the Unvested Shares and such other securities or property), provided that the aggregate purchase price payable for the Unvested Shares and all such other securities and property shall remain the same price that was original payable under the Repurchase Option to repurchase such Unvested Shares. Subject to the provisions of Section 5.2 above, in the event of a merger or consolidation of the Company with or into another entity or any other corporate reorganization, the Repurchase Option may be exercised by the Company’s successor.

5.6 Assignment of Repurchase Right. The Company may freely assign the Company’s Repurchase Option, in whole or in part, provided that any person who accepts an assignment of the Repurchase Option from the Company shall assume all of the Company’s rights and obligations with respect to the Repurchase Option (to the extent so assigned) under this Agreement.

6. COMPANY’S REFUSAL RIGHT. Unvested Shares shall be subject to the restrictions on transfer and the granting of encumbrances thereon as provided in Section 7 hereof. Before any Vested Shares (as defined in Section 5 hereof) held by Purchaser or any transferee of such Vested Shares (either sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including, without limitation, a transfer by gift or operation of law), the Company and/or its assignee(s) will have a right of first refusal to purchase the Vested Shares to be sold or transferred (the “Offered Shares”) on the terms and conditions set forth in this Section (the “Refusal Right”).

6.1 Notice of Proposed Transfer. The Holder of the Offered Shares will deliver to the Company a written notice (the “Notice”) stating: (a) the Holder’s bona fide intention to sell or otherwise transfer the Offered Shares; (b) the name and address of each proposed purchaser or other transferee of Offered Shares (“Proposed Transferee”); (c) the number of Offered Shares to be transferred to each Proposed Transferee; (d) the bona fide cash price or other consideration for which the Holder proposes to transfer the Offered Shares to each Proposed Transferee (the “Offered Price”); and (e) that the Holder acknowledges this Notice is an offer to sell the Offered Shares to the Company and/or its assignee(s) pursuant to the Company’s Refusal Right at the Offered Price as provided for in this Agreement.

6.2 Exercise of Refusal Right. At any time within thirty (30) days after the date the Notice is effective pursuant to Section 9.2, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all (or, with the consent of the Holder, less than all) the Offered Shares proposed to be transferred to any one or more of the Proposed Transferees named in the Notice, at the purchase price, determined as provided in Section 6.3 below.

6.3 Purchase Price. The purchase price for the Offered Shares purchased under this Section will be the Offered Price, provided that if the Offered Price consists of no legal consideration (as, for example, in the case of a transfer by gift), then the purchase price will be the fair market value of the Offered Shares as determined in good faith by the Company’s Board of Directors. If the Offered Price includes consideration other than cash, then the value of the non-cash consideration, as determined in good faith by the Company’s Board of Directors, will conclusively be deemed to be the cash equivalent value of such non-cash consideration.

6.4 Payment. The purchase price for the Offered Shares will be paid, at the option of the Company and/or its assignee(s) (as applicable), by check or by cancellation of all or a portion of any outstanding indebtedness owed by the Holder to the Company (or to such assignee, in the case of a purchase of Offered Shares by such assignee) or by any combination thereof. The purchase price will be paid without interest within sixty (60) days after the Company’s receipt of the Notice, or, at the option of the Company and/or its assignee(s), in the manner and at the time(s) set forth in the Notice.

5

6.5 Holder’s Right to Transfer. If all of the Offered Shares proposed in the Notice to be transferred to a given Proposed Transferee are not purchased by the Company and/or its assignee(s) as provided in this Section, then the Holder may sell or otherwise transfer such Offered Shares to such Proposed Transferee at the Offered Price or at a higher price, provided that (a) such sale or other transfer is consummated within one hundred twenty (120) days after the date the Notice is effective pursuant to Section 9.2, (b) any such sale or other transfer is effected in compliance with all applicable securities laws, and (c) such Proposed Transferee agrees in writing that the provisions of this Section will continue to apply to the Offered Shares in the hands of such Proposed Transferee. If the Offered Shares described in the Notice are not transferred to such Proposed Transferee within such one hundred twenty (120) day period, then a new Notice must be given to the Company pursuant to which the Company will again be offered the Refusal Right before any Shares held by the Holder may be sold or otherwise transferred.

6.6 Exempt Transfers. Notwithstanding the foregoing, the following transfers of Vested Shares will be exempt from the Refusal Right: (a) the transfer of any or all of the Vested Shares during Purchaser’s lifetime by gift or on Purchaser’s death by will or intestacy to Purchaser’s “Immediate Family” (as defined below) or to a trust for the benefit of Purchaser or Purchaser’s Immediate Family, provided that each transferee agrees in a writing satisfactory to the Company that the provisions of this Section will continue to apply to the transferred Vested Shares in the hands of such transferee; (b) any transfer of Vested Shares made pursuant to a statutory merger or statutory consolidation of the Company with or into another entity or entities (except that, subject to Section 6.7, unless the agreement of merger or consolidation expressly otherwise provides, the Refusal Right will continue to apply thereafter to such Vested Shares, in which case the surviving entity of such merger or consolidation shall succeed to the rights of the Company under this Section); or (c) any transfer of Vested Shares pursuant to the winding up and dissolution of the Company. As used herein, the term “Immediate Family” will mean Purchaser’s spouse, the lineal descendant or antecedent, father, mother, brother or sister, child, adopted child, grandchild or adopted grandchild of Purchaser or Purchaser’s spouse, or the spouse of any of the above or Spousal Equivalent, as defined herein. As used herein, a person is deemed to be a “Spousal Equivalent” provided the following circumstances are true: (i) irrespective of whether or not the Purchaser and the Spousal Equivalent are the same sex, they are the sole spousal equivalent of the other for the last twelve (12) months, (ii) they intend to remain so indefinitely, (iii) neither are married to anyone else, (iv) both are at least 18 years of age and mentally competent to consent to contract, (v) they are not related by blood to a degree of closeness that which would prohibit legal marriage in the state in which they legally reside, (vi) they are jointly responsible for each other’s common welfare and financial obligations, and (vii) they reside together in the same residence for the last twelve (12) months and intend to do so indefinitely.

6.7 Termination of Refusal Right. The Refusal Right will terminate as to all Shares: (a) on the effective date of the first sale of Common Stock of the Company to the public pursuant to a registration statement filed with and declared effective by the SEC under the Securities Act or, if expressly approved by the Board as terminating the Refusal Right, under the laws of any other country having substantially the same effect (other than a registration statement relating solely to the issuance of Common Stock pursuant to a business combination or an employee incentive or benefit plan) or (b) on any transfer or conversion of Shares made pursuant to a statutory merger or statutory consolidation of the Company with or into another entity or entities if the common stock of the surviving entity or any direct or indirect parent entity thereof is registered under the Securities Exchange Act of 1934, as amended.

7. ADDITIONAL RESTRICTIONS UPON SHARE OWNERSHIP OR TRANSFER.

7.1 Rights as a Stockholder. Subject to the terms and conditions of this Agreement, Purchaser will have all of the rights of a Stockholder of the Company with respect to the Shares from and after the date that Shares are issued to Purchaser until such time as Purchaser disposes of the Shares or the Company and/or its assignee(s) exercise(s) the Refusal Right or the Repurchase Option. Upon an exercise of the Refusal Right or the Repurchase Option, Purchaser will have no further rights as a holder of the Shares so purchased upon such exercise, other than the right to receive payment for the Shares so purchased in accordance with the provisions of this Agreement, and Purchaser will promptly surrender the stock certificate(s) evidencing the Shares so purchased to the Company for transfer or cancellation.

6

7.2 Escrow. As security for Purchaser’s faithful performance of this Agreement, Purchaser agrees, immediately upon receipt of the stock certificate(s) evidencing the Shares, to deliver such certificate(s) to the Secretary of the Company or other designee of the Company (the “Escrow Holder”), who is hereby appointed to hold such certificate(s) in escrow and to take all such actions and to effectuate all such transfers and/or releases of such Shares as are in accordance with the terms of this Agreement. Purchaser and the Company agree that Escrow Holder will not be liable to any party to this Agreement (or to any other person or entity) for any actions or omissions unless Escrow Holder is grossly negligent or intentionally fraudulent in carrying out the duties of Escrow Holder under this Agreement. Escrow Holder may rely upon any letter, notice or other document executed with any signature purported to be genuine and may rely on the advice of counsel and obey any order of any court with respect to the transactions contemplated by this Agreement. The Shares will be released from escrow upon termination of both the Refusal Right and the Repurchase Option.

7.3 Encumbrances on Shares. Without the Company’s prior written consent given with the approval of the Company’s Board of Directors, Purchaser may not grant a lien or security interest in, or pledge, hypothecate or encumber, any Unvested Shares.

7.4 Restrictions on Transfers. Unvested Shares may not be sold or otherwise transferred by Purchaser without the Company’s prior written consent. Purchaser hereby agrees that Purchaser shall make no disposition of the Shares (other than as permitted by this Agreement) unless and until:

(a) Purchaser shall have notified the Company of the proposed disposition and provided a written summary of the terms and conditions of the proposed disposition;

(b) Purchaser shall have complied with all requirements of this Agreement applicable to the disposition of the Shares, including but not limited to the Refusal Right, the Market Standoff and the Repurchase Option; and

(c) Purchaser shall have provided the Company with written assurances, in form and substance satisfactory to counsel for the Company, that (i) the proposed disposition does not require registration of the Shares under the Securities Act or under any state securities laws, and (ii) all appropriate actions necessary for compliance with the registration and qualification requirements of the Securities Act and any state securities laws, or of any exemption from registration or qualification, available thereunder (including Rule 144) have been taken.

Each person (other than the Company) to whom the Shares are transferred by means of one of the permitted transfers specified in this Agreement must, as a condition precedent to the validity of such transfer, acknowledge in writing to the Company that such person is bound by the provisions of this Agreement and that the transferred Shares are subject to the Company’s Refusal Right or the Repurchase Option granted hereunder and the market stand-off provisions of Section 4 hereof, to the same extent such Shares would be so subject if retained by the Purchaser.

7.5 Restrictive Legends and Stop-transfer Orders. Purchaser understands and agrees that the Company will place the legends set forth below or similar legends on any stock certificate(s) evidencing the Shares, together with any other legends that may be required by applicable laws, the Company’s Certificate of Incorporation or Bylaws, any other agreement between Purchaser and the Company or any agreement between Purchaser and any third party:

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR UNDER THE SECURITIES LAWS OF CERTAIN STATES. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS

7

PERMITTED UNDER THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. INVESTORS SHOULD BE AWARE THAT THEY MAY BE REQUIRED TO BEAR THE FINANCIAL RISKS OF THIS INVESTMENT FOR AN INDEFINITE PERIOD OF TIME. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON PUBLIC RESALE AND TRANSFER, INCLUDING THE RIGHT OF FIRST REFUSAL AND THE REPURCHASE OPTION HELD BY THE ISSUER AND/OR ITS ASSIGNEE(S), AND A MARKET STANDOFF AGREEMENT, AS SET FORTH IN A RESTRICTED STOCK PURCHASE AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH PUBLIC SALE AND TRANSFER RESTRICTIONS INCLUDING THE RIGHT OF FIRST REFUSAL, THE REPURCHASE OPTION AND THE MARKET STANDOFF ARE BINDING ON TRANSFEREES OF THESE SHARES.

Purchaser also agrees that, to ensure compliance with the restrictions imposed by this Agreement, the Company may issue appropriate “stop-transfer” instructions to its transfer agent, if any, and if the Company transfers its own securities, it may make appropriate notations to the same effect in its own records. The Company will not be required (a) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (b) to treat as owner of such Shares, or to accord the right to vote or pay dividends to any purchaser or other transferee to whom such Shares have been so transferred.

8. TAX CONSEQUENCES. PURCHASER UNDERSTANDS THAT PURCHASER MAY SUFFER ADVERSE TAX CONSEQUENCES AS A RESULT OF PURCHASER’S PURCHASE OR DISPOSITION OF THE SHARES. PURCHASER REPRESENTS (a) THAT PURCHASER HAS CONSULTED WITH ANY TAX ADVISER THAT PURCHASER DEEMS ADVISABLE IN CONNECTION WITH THE PURCHASE OR DISPOSITION OF THE SHARES AND (b) THAT PURCHASER IS NOT RELYING ON THE COMPANY FOR ANY TAX ADVICE. Purchaser hereby acknowledges that Purchaser has been informed that, with respect to Unvested Shares, unless an election is filed by Purchaser with the Internal Revenue Service (and, if necessary, the proper state taxing authorities) within 30 days after the purchase of the Shares electing, pursuant to Section 83(b) of the Internal Revenue Code (and similar state tax provisions, if applicable), to be taxed currently on any difference between the Purchase Price of the Unvested Shares and their Fair Market Value on the date of purchase, there will be a recognition of taxable income to Purchaser, measured by the excess, if any, of the Fair Market Value of the Unvested Shares, at the time they cease to be Unvested Shares, over the Purchase Price for such Shares. Purchaser represents that Purchaser has consulted any tax advisers Purchaser deems advisable in connection with Purchaser’s purchase of the Shares and the filing of the election under Section 83(b) and similar tax provisions. A form of Election under Section 83(b) is attached hereto as Exhibit 1 for reference. BY PROVIDING THE FORM OF ELECTION, NEITHER THE COMPANY NOR ITS LEGAL COUNSEL IS THEREBY UNDERTAKING TO FILE THE ELECTION FOR PURCHASER, WHICH OBLIGATION TO FILE SHALL REMAIN SOLELY WITH PURCHASER.

8

9. GENERAL PROVISIONS.

9.1 Successors and Assigns. The Company may assign any of its rights under this Agreement, including its rights to purchase Shares under the Refusal Right or the Repurchase Option. Neither Purchaser, nor any of Purchaser’s successors and assigns, may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior written consent of the Company. This Agreement shall be binding upon and inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer herein set forth, this Agreement will be binding upon Purchaser and Purchaser’s heirs, executors, administrators, legal representatives, successors and assigns.

9.2 Notices. Any and all notices required or permitted to be given to a party pursuant to the provisions of this Agreement will be in writing and will be effective and deemed to provide such party sufficient notice under this Agreement on the earliest of the following: (i) at the time of personal delivery, if delivery is in person; (ii) at the time an electronic confirmation of receipt is received, if delivery is by email; (iii) at the time of transmission by facsimile, addressed to the other party at its facsimile number specified herein (or hereafter modified by subsequent notice to the parties hereto), with confirmation of receipt made by both telephone and printed confirmation sheet verifying successful transmission of the facsimile; (iv) one (1) business day after deposit with an express overnight courier for United States deliveries, or two (2) business days after such deposit for deliveries outside of the United States, with proof of delivery from the courier requested; or (v) three (3) business days after deposit in the United States mail by certified mail (return receipt requested) for United States deliveries. Any notice for delivery outside the United States will be sent by email, facsimile or by express courier. Any notice not delivered personally or by email will be sent with postage and/or other charges prepaid and properly addressed to Purchaser at the last known address or facsimile number on the books of the Company, or at such other address or facsimile number as such other party may designate by one of the indicated means of notice herein to the other parties hereto or, in the case of the Company, to it at its principal place of business. Notices to the Company will be marked “Attention: Chief Financial Officer.” Notices by facsimile shall be machine verified as received.

9.3 Further Assurances. The parties agree to execute such further documents and instruments and to take such further actions as may be reasonably necessary to carry out the purposes and intent of this Agreement.

9.4 Entire Agreement. The Plan is incorporated herein by reference. The Plan and this Agreement, together with all Exhibits hereto, constitute the entire agreement and understanding of the parties with respect to the subject matter of this Agreement, and supersede all prior understandings and agreements, between the parties hereto with respect to the specific subject matter hereof.

9.5 Severability. If any provision of this Agreement is determined by any court or arbitrator of competent jurisdiction to be invalid, illegal or unenforceable in any respect, such provision will be enforced to the maximum extent possible given the intent of the parties hereto. If such clause or provision cannot be so enforced, such provision shall be stricken from this Agreement and the remainder of this Agreement shall be enforced as if such invalid, illegal or unenforceable clause or provision had (to the extent not enforceable) never been contained in this Agreement. Notwithstanding the forgoing, if the value of this Agreement based upon the substantial benefit of the bargain for any party is materially impaired, which determination as made by the presiding court or arbitrator of competent jurisdiction shall be binding, then both parties agree to substitute such provision(s) through good faith negotiations.

9.6 Execution. This Agreement may be entered into in two or more counterparts, each of which shall be deemed an original and all of which shall constitute one and the same agreement. This Agreement may be executed and delivered by facsimile and, upon such delivery, the facsimile signature will be deemed to have the same effect as if the original signature had been delivered to the other party.

[The remainder of this page has intentionally been left blank]

[Signature page follows]

9

IN WITNESS WHEREOF, the Company has caused this Restricted Stock Purchase Agreement to be executed by its duly authorized representative, and Purchaser has executed this Restricted Stock Purchase Agreement, as of the date first set forth above.

Exhibit

10

EXHIBIT 1

FORM OF SECTION 83(B) ELECTION

ELECTION UNDER SECTION 83(b) OF THE

INTERNAL REVENUE CODE

The undersigned Taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended, to include in gross income for the Taxpayer’s current taxable year the excess, if any, of the fair market value of the property described below at the time of transfer over the amount paid for such property, as compensation for services.

TAXPAYER’S ADDRESS:                                                                                                                                                        

SOCIAL SECURITY NUMBER:                                                                                                                                                

TAXABLE YEAR:                                                     Calendar Year _____

THIS ELECTION MUST BE FILED WITH THE INTERNAL REVENUE SERVICE (“IRS”), AT THE OFFICE WHERE THE TAXPAYER FILES ANNUAL INCOME TAX RETURNS, WITHIN 30 DAYS AFTER THE DATE OF TRANSFER OF THE PROPERTY, AND MUST ALSO BE FILED WITH THE TAXPAYER’S INCOME TAX RETURNS FOR THE CALENDAR YEAR. A COPY OF THE ELECTION HAS ALSO BEEN FURNISHED TO THE COMPANY. THE ELECTION CANNOT BE REVOKED WITHOUT THE CONSENT OF THE IRS.