Severance Payments; Annual Bonus. In consideration for your signing this agreement and allowing it to become effective, you will receive (i) payment of twelve (12) months of salary (the “Severance Payments” during the “Severance Period”) and (ii) a payment equal to 100% of your annual bonus opportunity ($201,744.35) (the “Annual Bonus”), in each case less applicable taxes and withholdings. Severance Payments will be made in accordance with the Company’s normal payroll practices during the Severance Period, beginning the first payroll period that is at least five (5) business days following the Effective Date (as defined in Section 6(e)). The Annual Bonus will be paid in one lump sum within fourteen (14) days of the Effective Date.

Benefits Coverage. Your Company-sponsored healthcare coverage will terminate as of July 31, 2023. Provided that you timely elect to receive healthcare continuation coverage pursuant to the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended, or applicable state law (“COBRA”), and so long as the Company can provide such benefit without violating the non-discrimination requirements of the law or incurring an excise tax, the Company will pay the portion of the premium for such coverage that is paid by the Company for active and similarly situated employees who receive the same type of coverage, such payment to be made for coverage from the termination date through the earliest of (x) the end of the Severance Period, (y) the date you are no longer eligible for COBRA coverage or (z) the date you become eligible for healthcare coverage from a subsequent employer (and you agree to promptly notify the Company of such eligibility). The remaining balance of any premium cost shall timely be paid by you on a monthly basis for as long as, and to the extent that, you remain eligible for COBRA coverage. All other Company-sponsored benefits will terminate effective as of the Separation Date.

Continued Vesting. Your outstanding options to purchase shares of the Company’s common stock and restricted stock units covering shares of the Company’s common stock that vest solely based on your continued employment or service (collectively, the “Time-Based Equity Awards”) will remain outstanding and eligible to vest and, as applicable, become exercisable upon the closing of the merger (the “Proposed Merger”) contemplated by that certain Agreement and Plan of Merger, dated July 14, 2023, between the Company, Frequency Merger Sub, Inc. and Korro Bio, Inc.; provided that the Merger closes and becomes effective on or before December 31, 2023. For the avoidance of doubt, you will forfeit your restricted stock units that do not vest solely based on your continued employment or service on the Separation Date and, in the event that the Merger does not close and become effective on or before December 31, 2023, the Time-Based Equity Awards.

You will cooperate fully with the Company in its defense of or other participation in any administrative, judicial or other proceeding arising from any investigation, charge, complaint or other action which has been or may be filed.

You agree not to disparage or defame the Company, its directors, officers and employees, Company products or services, or any Releasee, publicly or privately, directly or indirectly through others, by use of any words, actions, gestures or medium, including but not limited to on social media or other internet site. Nothing in this Section 5(b) or this Agreement shall prevent you from (i) testifying truthfully in response to a subpoena or other legal process; (ii) discussing terms and conditions of your employment with the Company, as permitted by the National Labor Relations Act; or (iii) communicating directly with, cooperating with, or providing information to, any federal, state or local government regulator, including, but not limited to, the U.S. Securities and Exchange Commission, the U.S. Commodity Futures Trading Commission, or the U.S. Department of Justice.

On behalf of yourself and your heirs and assigns, you hereby release and forever discharge the “Releasees” hereunder, consisting of the Company, and each of its directors, officers, managers, employees, agents and insurers, and all persons acting by, through, under or in concert with them, or any of them, of and from any and all manner of action or actions, cause or causes of action, in law or in equity, suits, debts, liens, contracts, agreements, promises, liability, claims, demands, damages, loss, cost or expense, of any nature whatsoever, known or unknown, fixed or contingent (hereinafter called “Claims”), which you now have or may hereafter have against the Releasees, or any of them, by reason of any matter, cause, or thing whatsoever from the beginning of time to the date hereof, including, without limiting the generality of the foregoing, any Claims arising out of, based upon, or relating to your recruitment, hire, employment, remuneration or separation from employment by the Releasees, including any Claims arising under any claims arising under the Age Discrimination in Employment Act (“ADEA”), as amended, 29 U.S.C. § 621, et seq.; Title VII of the Civil Rights Act of 1964, as amended by the Civil Rights Act of 1991, 42 U.S.C. § 2000 et seq.; the Equal Pay Act, as amended, 29 U.S.C. § 206(d); the Civil Rights Act of 1866, 42 U.S.C. § 1981; the Family and Medical Leave Act of 1993, 29 U.S.C. § 2601 et seq.; the Americans with Disabilities Act of 1990, 42 U.S.C. § 12101 et seq.; the False Claims Act , 31 U.S.C. § 3729 et seq.; the Employee Retirement Income Security Act, as amended, 29 U.S.C.

Notwithstanding the generality of the foregoing, you do not release any Claims (i) that arise from your ownership of vested equity securities of the Company, (ii) for indemnification by the Company or any of its affiliates pursuant to contract, directors’ and officers’ insurance or applicable law or (iii) that cannot be released as a matter of law including, without limitation, (A) your right to bring to the attention of the Equal Employment Opportunity or equivalent Massachusetts agency claims of discrimination, harassment, interference with leave rights, and retaliation; provided, however, that you do release your right to secure damages for any such alleged treatment, and (B) your right to communicate directly with, cooperate with, or provide information to, any federal, state or local government regulator, including, but not limited to, the U.S. Securities and Exchange Commission, the U.S. Commodity Futures Trading Commission, or the U.S. Department of Justice.

You have been informed that, by statute or common law, a general release of claims may not extend to Claims that you do not know or suspect to exist in your favor at the time of executing the release, where such Claims, if known to you, may have materially affected your decision to settle. Being aware of such statutory or common laws principles, you nonetheless agree to waive your right to pursue such unknown Claims against the Releasees.

In accordance with the Older Workers Benefit Protection Act of 1990, you should be aware of the following:

You have the right to consult with an attorney before signing this agreement;

You have twenty-one (21) days, from the date of this letter, to consider this Agreement; and

You have seven (7) days after signing this agreement to revoke this agreement, and this agreement will not be effective.

If you wish to revoke your acceptance of this agreement, you must deliver written notice stating your intent to revoke via email to James Abely at jabely@frequencytx.com, on or before 5:00 p.m. Eastern on the seventh (7^th) day after the date on which you sign this agreement. The eighth (8^th) day following your signature of this agreement without revocation shall be the effective date of this Agreement (“Effective Date”).