Form of Restricted Stock Unit Agreement under 2024 Inducement Stock Incentive Plan

Dyne Therapeutics, Inc.

RESTRICTED STOCK UNIT AGREEMENT

Granted under 2024 Inducement Stock Incentive Plan

Dyne Therapeutics, Inc. (the “Company”) hereby grants the following restricted stock units to the recipient named below pursuant to its 2024 Inducement Stock Incentive Plan (as amended through the date hereof, the “Plan”). The terms and conditions attached hereto are also a part hereof and incorporated herein by reference.

Notice of Grant

Vesting Schedule:

This grant of RSUs satisfies in full all commitments that the Company has to the Participant with respect to the issuance of stock, stock options or other equity securities.

Dyne Therapeutics, Inc.

Restricted Stock Unit Agreement

Granted under 2024 Inducement Stock Incentive Plan

Incorporated Terms and Conditions

For valuable consideration, receipt of which is acknowledged, the parties hereto agree as follows:

The Company has granted to the Participant, subject to the terms and conditions set forth in this Restricted Stock Unit Agreement (this “Agreement”) and in the Plan, an award with respect to the number of RSUs set forth in the Notice of Grant that forms part of this Agreement (the “Notice of Grant”). Each RSU represents the right to receive one share of common stock, $0.0001 par value per share, of the Company (the “Common Stock”) upon vesting of the RSU, subject to the terms and conditions set forth herein.

The RSUs evidenced by this Agreement were granted to the Participant pursuant to the inducement grant exception under Nasdaq Stock Market Rule 5635(c)(4), as an inducement that is material to the Participant’s employment with the Company.

The RSUs shall vest in accordance with the Vesting Schedule set forth in the Notice of Grant (the “Vesting Schedule”). Any fractional shares resulting from the application of any percentages used in the Vesting Schedule shall be rounded down to the nearest whole number of RSUs. Upon the vesting of the RSU, the Company will deliver to the Participant, for each RSU that becomes vested, one share of Common Stock, subject to the payment of any taxes pursuant to Section 7. The Common Stock will be delivered to the Participant as soon as practicable following each vesting date, but in any event within 30 days of such date.

In the event that the Participant ceases to be an employee, director or officer of, or consultant or advisor to, the Company or any other entity the employees, officers, directors, consultants, or advisors of which are eligible to receive awards under the Plan (an “Eligible Participant”) for any reason or no reason, with or without cause, all of the RSUs that are unvested as of the time of such cessation shall be forfeited immediately and automatically to the Company, without the payment of any consideration to the Participant, effective as of such cessation. The Participant shall have no further rights with respect to the unvested RSUs or any Common Stock that may have been issuable with respect thereto. If the Participant provides services to a subsidiary of the Company, any references in this Agreement to provision of services to the Company shall instead be deemed to refer to service with such subsidiary.

The Participant shall not sell, assign, transfer, pledge, hypothecate, encumber or otherwise dispose of, by operation of law or otherwise (collectively “transfer”) any RSUs, or any interest therein. The Company shall not be required to treat as the owner of any RSUs or issue any Common Stock to any transferee to whom such RSUs have been transferred in violation of any of the provisions of this Agreement.

The Participant shall have no rights as a stockholder of the Company with respect to any shares of Common Stock that may be issuable with respect to the RSUs until the issuance of the shares of Common Stock to the Participant following the vesting of the RSUs.

This Agreement is subject to the provisions of the Plan, a copy of which is furnished to the Participant with this Agreement.

(a) Acknowledgments; No Section 83(b) Election. The Participant acknowledges that he or she is responsible for obtaining the advice of the Participant’s own tax advisors with respect to the award of RSUs and the Participant is relying solely on such advisors and not on any statements or representations of the Company or any of its agents with respect to the tax consequences relating to the RSUs. The Participant understands that the Participant (and not the Company) shall be responsible for the Participant’s tax liability that may arise in connection with the acquisition, vesting and/or disposition of the RSUs. The Participant acknowledges that no election under Section 83(b) of the Internal Revenue Code of 1986, as amended (the “Code”), is available with respect to RSUs.

(b) Withholding. The Participant acknowledges and agrees that the Company has the right to deduct from payments of any kind otherwise due to the Participant any federal, state, local or other taxes of any kind required by law to be withheld with respect to the vesting of the RSUs. At such time as the Participant is not aware of any material nonpublic information about the Company or the Common Stock and is not prohibited from doing so by the Company’s insider trading policy or otherwise, the Participant shall execute the instructions set forth in Schedule A attached hereto (the “Durable Automatic Sell-to-Cover Instruction”) as the means of satisfying such tax obligation. If the Participant is required to but does not execute the Durable Automatic Sell-to-Cover Instruction prior to an applicable vesting date, then the Participant agrees that if under applicable law the Participant will owe taxes at such vesting date on the portion of the award then vested the Company shall be entitled to immediate payment from the Participant of the amount of any tax required to be withheld by the Company. The Company shall not deliver any shares of Common Stock to the Participant until it is satisfied that all required withholdings have been made.

(a) No Right to Continued Service. The Participant acknowledges and agrees that, notwithstanding the fact that the vesting of the RSUs is contingent upon his or her continued service to the Company, this Agreement does not constitute an express or implied promise of continued service relationship with the Participant or confer upon the Participant any rights with respect to a continued service relationship with the Company or any affiliate of the Company.

(b) Section 409A. The RSUs awarded pursuant to this Agreement are intended to be exempt from or comply with the requirements of Section 409A of the Code and the Treasury Regulations issued thereunder (“Section 409A”). The delivery of shares of Common Stock on the vesting of the RSUs may not be accelerated or deferred unless permitted or required by Section 409A.

(c) Participant’s Acknowledgments. The Participant acknowledges that he or she: (i) has read this Agreement; (ii) has been represented in the preparation, negotiation and execution of this Agreement by legal counsel of the Participant’s own choice or has voluntarily declined to seek such counsel; (iii) understands the terms and consequences of this Agreement; (iv) is agreeing, in accepting this award, to be bound by any clawback policy that the Company has in place or may adopt in the future, including the Company’s Dodd-Frank Compensation Recovery Policy; and (iv) is fully aware of the legal and binding effect of this Agreement.

(d) Governing Law. This Agreement shall be construed, interpreted and enforced in accordance with the internal laws of the State of Delaware without regard to any applicable conflicts of laws provisions.

Schedule A

DURABLE AUTOMATIC SELL-TO-COVER INSTRUCTION

This Durable Automatic Sell-to-Cover Instruction (this “Instruction”), which is being delivered to Dyne Therapeutics, Inc. (the “Company”) by the undersigned on the date set forth below (the “Adoption Date”), relates to the Covered RSUs (as defined following my signature below). This Instruction provides for “eligible sell-to-cover transactions” (as described in Rule 10b5-1(c)(1)(ii)(D)(3) under the Securities Exchange Act of 1934 (the “Exchange Act”)) and is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c)(1) under the Exchange Act.

I acknowledge that upon vesting and settlement of any Covered RSUs in accordance with the applicable RSU’s terms, whether vesting is based on the passage of time or the achievement of performance goals, I will have compensation income equal to the fair market value of the shares of the Company’s common stock subject to the RSUs that are settled on such settlement date and that the Company is required to withhold income and employment taxes in respect of that compensation income.

I desire to establish a plan and process to satisfy such withholding obligation in respect of all Covered RSUs through an automatic sale of a portion of the shares of the Company’s common stock that would otherwise be issuable to me on each applicable settlement date, such portion to be in an amount sufficient to satisfy such withholding obligation, with the proceeds of such sale delivered to the Company in satisfaction of such withholding obligation.

I understand that the Company has arranged for the administration and execution of its equity incentive programs and the sale of securities by participants thereunder pursuant to a platform administered by a third party (the “Administrator”) and the Administrator’s designated brokerage partner.

Upon any settlement of any of my Covered RSUs after the 30th day following the Adoption Date (or if I am an officer of the Company on the Adoption Date, after the later of: (i) the 90th day following the Adoption Date or (ii) two business days following the disclosure of the Company’s financial results in Form 10-Q or Form 10-K for the completed fiscal quarter in which this Instruction was adopted (or, with respect to this clause (ii), if sooner, the 120th day after adoption of this Instruction), I hereby appoint the Administrator (or any successor administrator) to automatically sell such number of shares of the Company’s common stock issuable with respect to such RSUs that vested and settled as is sufficient to generate net proceeds sufficient to satisfy the Company’s minimum1 statutory withholding obligations with respect to the income recognized by me in connection with the vesting and settlement of such RSUs (based on minimum statutory withholding rates for all tax purposes, including payroll and social security taxes, that are applicable to such income), and the Company shall receive such net proceeds in satisfaction of such tax withholding obligation.

1 An “eligible sell-to-cover transaction” is a contract, instruction or plan that authorizes an agent to sell only such securities as are necessary to satisfy tax withholding obligations (i.e., minimum statutory withholding obligations) arising exclusively from the vesting of a compensatory award, and the Participant does not otherwise exercise control over the timing of such sales.

I hereby appoint the Chief Executive Officer, principal financial officer and senior legal officer, and any of them acting alone and with full power of substitution, to serve as my attorneys in fact to arrange for the sale of shares of the Company’s common stock in accordance with this Instruction. I agree to execute and deliver such documents, instruments and certificates as may reasonably be required in connection with the sale of the shares of common stock pursuant to this Instruction.

I hereby certify that, as of the Adoption Date:

Print Name: _________________________________

Date: ______________________________________