Amended and Restated Employment Agreement, dated March 11, 2020, by and between the Registrant and Richard Wooster

29 Hartwell Avenue

Lexington, MA 02421

P ###-###-####

Amended and Restated Employment Agreement

Position. Your position with the Company is Chief Scientific Officer and you report to Ronald Renaud, Chief Executive Officer. You agree to devote your full business time, best efforts, skill, knowledge, attention and energies to the advancement of the Company’s interests and the performance of your duties as an employee of the Company and not to engage in any other business activities without prior approval of the Company.

Base Salary. The Company will pay you a salary at the bi-weekly rate of $16,153.85 (which is equivalent to an annualized rate of $420,000.00 per year), payable in accordance with the Company’s standard payroll schedule and subject to applicable tax and other withholdings as required by law. Such base salary may be subject to periodic review and adjustments at the Company’s sole discretion.

Discretionary Bonus. You will be eligible to receive an annual cash discretionary bonus of up to 40% of your base salary (the “bonus”) in accordance with the terms of the applicable bonus plan. The amount, if any, of the cash bonus payment, and the Company’s determination of your performance, corporate objectives and business conditions at the Company are all within the sole discretion of the Company. Eligibility for and earning of the bonus, which is also a retention incentive that you remain employed by the Company, requires the you be employed for the full period covered by the bonus as well as on the date the bonus is to be paid. Your eligibility for the bonus is also contingent on approval by the Board of Directors of the Company (the “Board”). The Company expects to review your job performance on an annual basis and to discuss with you the criteria which the Company will use to assess your performance for bonus purposes. The Company also may make adjustments in the targeted amount of your bonus in the Company’s sole discretion.

Benefits. You will be eligible to participate in the Company’s employee benefits and insurance programs generally made available from time to time to its full-time employees, in accordance with, and provided you are eligible under, the plan documents governing those programs. You will also be eligible for up to 20 of

Incentive Equity Awards. In connection with your ongoing employment, the Company may propose to the Board from time to time, that a stock option grant be made to you of Company’ common stock pursuant to the Company’s 2018 Equity Incentive Plan (the “Proposed Grant”). Any Proposed Grant will be subject to the terms and conditions of a Option Agreement to be entered into by you and the Company. Your ownership of the common stock will be subject to a vesting schedule and will be contingent on your continued employment or continuous service as a consultant or advisor with the Company.

Severance. Without otherwise limiting the “at-will” nature of your employment, in the event your employment is terminated by the Company without Cause (as defined below) or you terminate for Good Reason, you shall be entitled to the base salary that has accrued and to which you are entitled as of the effective date of such termination, and further, subject to the conditions set forth in the second paragraph of this Severance section, the Company shall, for a period of nine (9) months following your termination date: (i) continue to pay you, in accordance with the Company’s regularly established payroll procedure, your base salary as Severance; and (ii) provided you are eligible for and timely elect to continue receiving group medical insurance pursuant to the “COBRA” law, continue to pay the share of the premium for health coverage that is paid by the Company for active and similarly-situated employees who receive the same type of coverage, unless the Company’s provision of such COBRA payments will violate the non-discrimination requirements of applicable law, in which case this benefit will not apply. If, in the twelve months following a Change of Control, the Company terminates your employment without Cause or you terminate for Good Reason, the Company, subject to the conditions set forth in the second paragraph of this Severance section, will: (a) extend the Severance benefits described in (i) and (ii) above for an additional three (3) months, such that the total severance benefit period shall be twelve (12) months; (b) accelerate the vesting of all unvested stock options, restricted stock or other equity awards held by you as of the date your employment is terminated such that 100% of such options, restricted stock or equity award shall become fully vested and, if applicable, exercisable effective as of such date (except as described in the next paragraph); and (c) pay to you a bonus amount equal to 1x your target annual bonus for the year in which termination of employment occurs.

Parachute Treatment. Notwithstanding any other provision of this Agreement to the contrary, if payments and benefits provided for under this Agreement together with any payments or benefits under any other agreement or arrangement between the Company or any of its affiliates and you are considered “excess parachute payments” under Section 280G of the Internal Revenue Code (the “Code”), then such excess parachute payments plus any other payments made by the Company and its affiliates that you are entitled to receive that are considered excess parachute payments shall be limited to the greatest amount that may be paid to you under Section 280G of the Code without causing any loss of deduction to the Company under such Code Section, but only if, by reason of such reduction, the “Net After Tax Benefit” (as defined below) to you shall exceed the net after tax benefit if such reduction was not made. “Net After Tax Benefit” for purposes of this Agreement shall mean the sum of (i) the total amounts payable to you that would constitute an “excess parachute payment” within the meaning of Section 280G of the Code, less (ii) the amount of federal, state and other income taxes payable with respect to the foregoing calculated at the maximum marginal tax rate for each year in which the foregoing shall be paid to you (based upon the rate in effect for such year as set forth in the Code at the time of termination of your employment or the change in control), less (iii) the amount of excise taxes imposed with respect to the payments and benefits described above by Section 4999 of the Code. The determination of whether payments would be considered excess parachute payments and the calculation of all the amounts referred to in this section shall be made reasonably and in good faith by the parties, provided, that if the parties cannot agree, then such determination (and supporting calculations) shall be made by attorneys, accountants, or an executive compensation consulting firm each as selected by the Company at the expense of the Company (the “280G Service Providers”). Any determination by the 280G Service Providers made in good faith shall be binding upon the Company and you.

Tax Acknowledgement. All forms of compensation referred to in this Agreement are subject to all applicable federal, state and/or local withholding and/or payroll taxes, and the Company may withhold from any amounts payable to you in order to comply with such withholding obligations and you shall be responsible for all applicable taxes with respect to such compensation. You hereby acknowledge that the Company does not have a duty to design its compensation policies in a manner that minimizes your tax liabilities, and you will not make any claim against the Company or its board of directors related to tax liabilities arising from your compensation. You further acknowledge that you are not relying upon the advice or representation of the Company with respect to the tax treatment of any of the compensation set forth in this Agreement.

409A Compliance. This Agreement is intended to provide payments that are exempt from or compliant with Section 409A, and should be interpreted consistent with that intent. The attached exhibit entitled “Payments Subject to Section 409A” is hereby appended to the Agreement as Attachment A and, if applicable, replaces any previous such attachment concerning the same subject matter.

Interpretation, Amendment, Enforcement and Complete Agreement. This Agreement, the Employee Non-Competition, Non-Solicit, Confidentiality and Invention Assignment Agreement which you previously executed and which you reaffirm, and any plans and agreements applicable to the incentive equity awards referred in Section 5 of this Agreement constitute the complete agreement between you and the Company, contain all of the terms of your employment with the Company and supersede any prior agreements, amendments, representations or understandings (whether written, oral or implied) between you and the Company. This Agreement shall be amended only by a writing signed by the Chief Executive Officer of the Company and you. The terms of this Agreement will be governed by statutes and common law of The Commonwealth or Massachusetts without regard to the conflict of laws provisions. You and the Company hereby irrevocably submit to and acknowledge and recognize the exclusive personal jurisdiction of the federal and state courts located in The Commonwealth of Massachusetts (which courts for purposes of this Agreement, are the only courts of competent jurisdiction) in connection with any dispute or any claim related to this Agreement or the subject matter hereof.

At-Will Employment. Your employment with the Company will be on an “at will” basis. In other words, you or the Company may terminate your employment for any reason and at any time, with or without cause.

/s/ Richard Wooster

It is intended that each installment of the severance payments under the letter agreement shall be treated as a separate “payment” for purposes of Section 409A of the Internal Revenue Code of 1986, as amended (“Section 409A”). Neither the Company nor you shall have the right to accelerate or defer the delivery of any such payments except to the extent specifically permitted or required by Section 409A.

If, as of the date of your “separation from service” from the Company, you are not a “specified employee” (within the meaning of Section 409A), then each installment of the severance payments shall be made on the dates and terms set forth in the letter agreement.

If, as of the date of your “separation from service” from the Company, you are a “specified employee” (within the meaning of Section 409A), then:

Each installment of the severance payments due under the letter agreement that is paid within the short-term deferral period (as defined under Section 409A) shall be treated as a short-term deferral within the meaning of Treasury Regulation Section l.409A-l(b)(4) to the maximum extent permissible under Section 409A and shall be paid on the dates and terms set forth in the letter agreement; and

Each installment of the severance payments due under the letter agreement that is not described in this Attachment A, Section I (c)(i) and that would, absent this subsection, be paid within the six-month period following your “separation from service” from the Company shall not be paid until the date that is six months and one day after such separation from service (or, if earlier, your death), with any such installments that are required to be delayed being accumulated during the six-month period and paid in a lump sum on the date that is six months and one day following your separation from service and any subsequent installments, if any, being paid in accordance with the dates and terms set forth herein; provided, however, that the preceding provisions of this sentence shall not apply to any installment of payments if and to the maximum extent that such installment is deemed to be paid under a separation pay plan that does not provide for a deferral of compensation by reason of the application of Treasury Regulation 1.409A-1(b)(9)(iii) (relating to separation pay upon an involuntary separation from service). Any installments that qualify for the exception under Treasury Regulation Section 1.409A-1(b)(9)(iii) must be paid no later than the last day of your second taxable year following the taxable year in which the separation from service occurs.