Exhibit A Definitions

On behalf of OvaScience, Inc. (the “Company”), I am pleased to offer you employment with the Company. The purpose of this letter agreement (the “Agreement”) is to summarize the terms of your employment with the Company, should you accept our offer.

1.    Employment.

(a)    You will be employed by the Company or one of its subsidiaries, effective January 5, 2016 (the “Start Date”). Beginning on the Start Date, you will be employed by OvaScience, Limited, a subsidiary of the Company organized and existing under the laws of England. Effective immediately following the date on which you obtain legal authorization to work in the United States, your employment will be transferred to the Company. During the period you are employed by OvaScience, Limited, the terms of your employment will be governed under the terms of the letter of appointment attached hereto as Attachment 1 (the “UK Appointment Letter”). The UK Appointment Letter will cease to have any force or effect immediately upon the transfer of your employment to the Company and thereafter the terms and conditions of your employment will be governed solely under this Agreement.

(b)    You will initially serve as the Chief Executive Officer Elect of the Company, reporting to the current Chief Executive Officer and the Company’s Board of Directors (the “Board”). Effective July 1, 2016, you will serve on a full-time basis as Chief Executive Officer of the Company. In this role, you will report to the Company’s Board, and have such duties and responsibilities as are customary for such position, and as are otherwise assigned to you from time to time by the Board. From the Start Date, you agree to devote your full business time, best efforts, skill, knowledge, attention, and energies to the advancement of the Company’s business and interests and to the performance of your duties and responsibilities as an employee of the Company and not to engage in any other business activities without prior approval from the Board.

(c)    The parties acknowledge that you are currently a member of the Board, and shall continue as a Class I Director upon being appointed as the Chief Executive Officer of the Company. The Board of Directors shall nominate you for election as a member of the Board at every shareholder meeting during your employment as the Chief Executive Officer at which your term as a director would otherwise expire. You agree to accept such appointment and to serve during all or any part of your employment as the Chief Executive Officer with the Company as a member of the Board, without any compensation therefore other than as specified herein. You agree that if your employment is terminated for any reason whatsoever, you will resign, at the Company’s request, from the Board and from any other positions you have as an officer or director of any of the Company’s direct or indirect subsidiaries and any other entity affiliated with the Company in which you are serving as an officer or director at the request of the Company. You acknowledge that you may serve as a member of the board of directors of up to two companies (other than the Company), and that only one of such companies may be a “public company,” which is a company with a class of securities registered under the Securities Exchange Act of 1934, provided that (i) such companies do not compete with the business of the Company, (ii) such board activities have been disclosed in writing to and approved by the Board, which approval shall not be unreasonably withheld and (iii) such service, whether individually or in the aggregate, does not materially interfere or conflict with the performance of your duties and responsibilities as an officer of the Company.

2.    Term. Your employment will continue for a five year term, expiring December 31, 2020 (the “Expiration Date”), unless terminated earlier pursuant to Section 10 of this Agreement. The Company and you will negotiate in good faith on an extension of your term of employment and will commence such negotiations no later than December 2019.

3.    Compensation. As compensation for your services to the Company, you shall receive base salary payments at the following rates based on years of services:

Your base salary shall at all times be subject to applicable taxes and withholdings and payable in accordance with the Company’s then prevailing payroll practices. Please note that the annualized amount of your salary as described above is set forth as a matter of convenience, and shall not constitute or be interpreted as an agreement by the Company to employ you for any specific period of time.

4.    Sign On Bonus. OvaScience, Limited will pay you a sign on bonus of $200,000.00, less applicable taxes and withholdings, payable on OvaScience, Limited’s first regular payroll date following your start date. If you terminate your employment for any reason prior to the date that you assume the title of the Company’s Chief Executive Officer, you will repay the Company the net amount of the sign on bonus you received and assist OvaScience, Limited and the Company (as applicable) to file claims with any applicable taxing authority to recoup on the Company’s behalf any income and payroll tax paid by the Company in connection with the sign on bonus.

5.    Bonus. You shall be eligible to receive an annual bonus during your employment hereunder, commencing with respect to fiscal year 2016, in accordance with the annual incentive program applicable generally to senior executives of the Company. The amount of the annual bonus will be based on the achievement of individual and corporate performance objectives established by the Board for the applicable year. Your target annual bonus will be 60% of your then current base salary. The annual bonus you will earn will be determined on a sliding scale based on the achievement of the applicable performance objectives (the “Performance Objectives”) as determined by the Board in its sole discretion. If your achievement of the Performance Objectives is 100% or less, you will receive that percentage of your target annual bonus equal to your percentage achievement of the Performance Objectives. If your achievement of the Performance Objectives is greater than 100%, you will receive that percentage (up to a maximum of 150%) of your target annual bonus equal to the sum of (a) 100% plus (b) the product of 2.5 and the amount by which your achievement of the Performance Objectives exceeds 100%. By way of example, (a) you will earn 50% of the annual bonus target if you achieve 50% of the Performance Objectives, (b) you will earn 100% of the annual bonus target if you achieve 100% of the Performance Objectives, (c) you will earn 125% of the annual bonus target if you achieve 110% of the Performance Objectives and (d) you will earn 150% of the annual bonus target if you achieve 120% or more of the Performance Objectives. Any annual bonus payable under this Section 5 shall be paid to you by no later than March 15th of the year following the year in which such bonus is earned. To receive an annual bonus for a year, you must be employed by the Company on December 31 of the year to which the bonus relates.

6.    Benefits. During the period you are employed by OvaScience, Limited, you will be eligible to participant in any and all benefit programs that OvaScience, Limited establishes and makes available to its employees from time to time, provided you meet the specific eligibility criteria as set forth in (and subject to all provisions of) the plan documents governing those programs. Once your employment is transferred to the Company, you will be eligible to participate in any and all benefit programs that the Company establishes and makes available to its employees from time to time, provided you meet the specific eligibility criteria as set forth in (and subject to all provisions of) the plan documents governing those programs, provided that your service with OvaScience, Limited shall be credited as service with the Company for purposes of meeting eligibility requirements. The benefits made available by the Company, and the rules, terms and conditions for participation in such benefit plans, may be changed by the Company at any time and from time to time without advance notice.

7.    Vacation. You will be eligible to accrue up to a maximum of twenty-five (25) days of paid vacation per calendar year. The number of vacation days for which you are eligible shall accrue at the rate of 2.083 days per month that you are employed during such calendar year, and shall be subject to the Company’s vacation policies and practices as in effect from time to time.

8.    Equity.

(a)    On the Start Date, subject to the approval of the Board, the Company will grant to you a stock option (the “Option”) under the Company’s 2012 Stock Incentive Plan (the “Plan”) for the purchase of an aggregate of 250,000 shares of common stock of the Company at a price per share equal to the fair market value (under the Plan) of a share of common stock as of the date of the grant. The Option shall be (i) made up of incentive stock options to the extent legally permissible, and otherwise shall be nonstatutory stock options, (ii) subject to all terms of the Plan and a separate option agreement, and (iii) subject to a vesting schedule of 4 years, with 25% of the shares vesting on the first anniversary of the Start Date and 6.25% of the shares vesting each quarter thereafter.

(b)    On the Start Date, subject to the approval of the Board, the Company will grant to you a restricted stock unit award representing the right to receive 250,000 shares of the Company’s common stock (the “RSUs”). The RSUs shall vest over four (4) years, with 25% of the RSUs vesting on the first anniversary of the Start Date and 6.25% of the RSUs vesting each quarter thereafter. The RSUs shall be granted under and subject to the terms of the Plan and a Restricted Stock Unit Award Agreement (the “RSU Agreement”) between you and the Company.

(c)    If you remain employed by the Company, at the first regularly scheduled meeting of the Board or the Compensation Committee (whichever occurs first) in 2017, the Company will grant to you a stock option (the “2017 Performance Option”) under the Plan for the purchase of that number of shares of common stock of the Company (up to a maximum of 250,000 shares) equal to that percentage (up to a maximum of 100%) of 250,000 shares equal to the percentage achievement of the Performance Objectives as shall be determined for 2016. The per share exercise price of the 2017 Performance Option shall be the fair market value (under the Plan) of a share of common stock as of the date of the grant.  The 2017 Performance Option shall be (i) made up of incentive stock options to the extent legally permissible, and otherwise shall be nonstatutory stock options, (ii) subject to all terms of the Plan and a separate option agreement, and (iii) subject to a vesting schedule of four (4) years, with 25% of the shares vesting on the first anniversary of the grant date and 6.25% of the shares vesting each quarter thereafter. Notwithstanding the foregoing, the grant of the 2017 Performance Option shall be subject to the availability of shareholder approved shares for the Plan and Board approval. The Board may elect, in its sole discretion, to grant additional options in 2017, based on its assessment of your level of performance, the Company’s achievement of its business goals, special contributions that you may have made during 2016 or other factors that the Board may deem appropriate.

(d)    If you remain employed by the Company, at the first regularly scheduled meeting of the Board or the Compensation Committee (whichever occurs first) in 2018, the Company will grant to you a stock option (the “2018 Performance Option”) under the Plan for the purchase of that number of shares of common stock of the Company (up to a maximum of 250,000 shares) equal to that percentage (up to a maximum of 100%) of 250,000 shares equal to the percentage achievement of the Performance Objectives as shall be determined for 2017. The per share exercise price of the 2018 Performance Option shall be the fair market value (under the Plan) of a share of common stock as of the date of the grant.  The 2018 Performance Option shall be (i) made up of incentive stock options to the extent legally permissible, and otherwise shall be nonstatutory stock options, (ii) subject to all terms of the Plan and a separate option agreement, and (iii) subject to a vesting schedule of 4 years, with 25% of the shares vesting on the first anniversary of the grant date and 6.25% of the shares vesting each quarter thereafter. Notwithstanding the foregoing, the grant of the 2018 Performance Option shall be subject to the availability of shareholder approved shares for the Plan and Board approval. The Board may elect, in its sole discretion, to grant additional options in 2018, based on its assessment of your level of performance, the Company’s achievement of its business goals, special contributions that you may have made during 2017 or other factors that the Board may deem appropriate.

9.    Other Benefits.

10.    Termination. The Company may terminate your employment at any time prior to the Expiration Date with or without Cause (as defined on Exhibit A attached hereto), because of your death or because of your Disability (as defined on Exhibit A attached hereto). You may resign your employment at any time prior to the Expiration Date with or without Good Reason (as defined on Exhibit A attached hereto). The date on which the termination of your employment becomes effective is the “Termination Date.” If your employment terminates for any reason, you will receive (i) your accrued base salary through the Termination Date; (ii) any earned, but unpaid annual bonus for the prior calendar year; (iii) unpaid expense reimbursements; and (iv) any vested benefits you may have under any employee benefit plan of the Company (the “Accrued Obligations”) on or before the time required by law but in no event more than 30 days after the Termination Date.

11.    Severance Benefits Upon Termination by the Company Without “Cause” or by you for “Good Reason”.

(a)    If the Company terminates your employment without Cause (as defined on Exhibit A attached hereto) or you terminate your employment for Good Reason (as defined on Exhibit A), in addition to the Accrued Obligations, you shall be eligible to receive the following severance benefits: (a) severance pay in an amount equal to eighteen (18) months of your base salary as in effect at the time of your termination, payable in accordance with the Company’s regular payroll procedures proportionately over a eighteen (18) month period following the termination of your employment (such period, the “Severance Period”); and (b) should you be eligible for and elect to continue receiving group medical and dental insurance coverage under the law known as COBRA, the Company shall continue to pay on your behalf that portion of the monthly premiums for such coverage that it pays for active and similarly situated employees receiving the same type of coverage, through the earlier of (x) the last day of the Severance Period, or (y) the date that you become eligible for group health and/or dental insurance coverage from any new employer; provided that, this payment will be treated as a taxable payment, subject to imputed income tax.

(b)    In addition, to the severance benefits described above, if a “Change in Control Event” (as defined on Exhibit A attached hereto) occurs and, within one (1) year of such Change in Control Event, your employment is terminated by the Company (or any successor) without “Cause” (as defined on Exhibit A) or by you for “Good Reason” (as defined on Exhibit A), all outstanding unvested Options and RSUs will fully vest and become exercisable effective as of the Termination Date.

(c)    No severance pay or other benefit hereunder shall be provided to you unless, within sixty (60) days following the date that your employment is terminated, you first execute and do not revoke a separation agreement in a form prepared by and acceptable to the Company, which shall include, at a minimum, a full release of all claims against the Company (as well as its parents, subsidiaries and affiliates, and its and their, executives, officers, directors, employees, consultants, agents, shareholders, and assigns), as well as non-disparagement and confidentiality provisions in favor of the Company (the “Separation Agreement”). The severance payments shall commence on the first payroll period following the date the Separation Agreement becomes effective (the “Payment Date”). Notwithstanding the payment requirements set forth in the immediately preceding sentence, if the sixty (60) day period following the date your separation from service begins in one tax year and ends in the following tax year, the Company will commence payment on the next regular payroll date following the later of January 1 of the second tax year and the date the Separation Agreement becomes enforceable and no longer subject to revocation. The first such payment will include a catch-up payment equal to all amounts you otherwise would have received under Section 11(a) prior to the first payment. The distribution of any severance payments shall be subject to the provisions of Exhibit B attached hereto.

12.    Limitation on Payments. 

(a)    You shall bear all expense of, and be solely responsible for, all Federal, state, local or foreign taxes due with respect to any payment received by or in respect of you hereunder, including any excise tax imposed by Section 4999 of the Code (the “Excise Tax”); provided, however, that any payment or benefit received or to be received by you, whether payable under the terms of this Agreement or any other plan, arrangement or agreement with the Company or an affiliate (collectively, the “Payments”), that would constitute a “parachute payment” within the meaning of Section 280G of the Internal Revenue Code of 1986, as amended (the “Code”), shall be reduced to the extent necessary so that no portion thereof shall be subject to the Excise Tax, but only if, by reason of such reduction, the “net after-tax benefit” (as defined below) received by you shall exceed the net after-tax benefit that would be received by you if no such reduction was made.

(b)    For purposes of Section 12, the “net after-tax benefit” shall mean (i) the Payments which you receive or are then entitled to receive from the Company or its affiliates that would constitute “parachute payments” within the meaning of Section 280G of the Code, less (ii) the amount of all Federal, state and local income and employment taxes payable by you with respect to the foregoing, calculated at the highest marginal income tax rate for each year in which the foregoing shall be paid to you (based on the rate in effect for such year as set forth in the Code as in effect at the time of the first payment of the foregoing), less (iii) the amount of Excise Tax imposed with respect to the payments and benefits described in clause (i) above.

(c)    All determinations under this Section 12 shall be made by an accounting firm that is selected for this purpose by the Board prior to the Change in Control Event (the “280G Firm”).  All fees and expenses of the 280G Firm shall be borne by the Company.  The Company shall direct the 280G Firm to submit any determination it makes under this Section 12 and detailed supporting calculations to both you and the Company as soon as reasonably practicable.

  

(d)    If the 280G Firm determines that one or more reductions are required under Section 12, the 280G Firm shall also determine which Payments shall be reduced (first from cash payments and then from non-cash benefits) to the extent necessary so that no portion thereof shall be subject to the excise tax imposed by Section 4999 of the Code, and the Company shall pay such reduced amount to you.  The 280G Firm shall make reductions required under this Section 12 in a manner that maximizes the net after-tax amount payable to you.  As a result of the uncertainty in the application of Section 280G at the time that the 280G Firm makes its determinations under this Section 12, it is possible that amounts shall have been paid or distributed to you that should not have been paid or distributed (collectively, the “Overpayments”), or that additional amounts should be paid or distributed to you (collectively, the “Underpayments”).  If the 280G Firm determines, based on either the assertion of a deficiency by the Internal Revenue Service against the Company or you, which assertion the 280G Firm believes has a high probability of success, or controlling precedent or substantial authority, that an Overpayment has been made, you shall promptly repay to the Company, without interest, an amount equal to such Overpayment; provided, however, that no loan shall be deemed to have been made and no amount shall be payable by you to the Company unless, and then only to the extent that, the deemed loan and payment would either reduce the amount on which you are subject to tax under Section 4999 of the Code or generate a refund of tax imposed under Section 4999 of the Code. If the 280G Firm determines based upon controlling precedent or substantial authority that an Underpayment has occurred, the 280G Firm shall notify you and the Company of such determination and the Company shall promptly pay the amount of such Underpayment to you.

(e)    The parties shall provide the 280G Firm access to and copies of any books, records, and documents in their possession as reasonably requested by the 280G Firm, and otherwise cooperate with the 280G Firm in connection with the preparation and issuance of the determinations and calculations contemplated by this Section 12.

13.    Indemnification. During the Term and thereafter, the Company shall indemnify and hold you harmless, to the maximum extent permitted by the laws of Delaware, against any and all damages, costs, liabilities, losses and expenses (including reasonable attorneys’ fees) as a result of any claim or proceeding (whether civil, criminal, administrative or investigative), or any threatened claim or proceeding (whether civil, criminal, administrative or investigative), against you that arises out of or relates to your service as an officer, director or employee, as the case may be, of the Company, or your service in any such capacity or similar capacity with any affiliate of the Company or other entity at the Company’s request and to promptly advance to you such expenses, including litigation costs and attorneys’ fees, upon written request with appropriate documentation of such expense upon receipt of an undertaking by you or on the your behalf to repay such amount if it shall ultimately be determined that you are not entitled to be indemnified by the Company under the law of Delaware. During the Term and thereafter, the Company also shall provide you with coverage under its current directors’ and officers’ liability policy to the same extent that it provides such coverage to its other executive officers.

14.    Notices. Any purported termination of employment by the Company for Cause or by you for Good Reason shall be communicated to the other party through written notice, indicating the specific grounds for such termination. Such notice, and all other communications which are required or may be given pursuant to the terms of this Agreement, shall be sufficient in all respects if given in writing and shall be deemed given (i) if delivered personally, on the date of delivery, (ii) if mailed by certified or registered mail, return receipt requested and postage prepaid, three (3) days after the mailing date, (iii) if sent via a nationally recognized overnight courier, on the next business day thereafter, or (iv) if sent via facsimile confirmed in writing to the recipient, or via email, on the next business day thereafter, in each case, if to the Company, at the Company’s principal place of business, and if to you at the most recent home address (and/or, as applicable, the most recent personal email address) which you have provided to the Company or to such other address or addresses as either party shall have designated in writing to the other party.

15.    Invention, Non-Disclosure, Non-Competition and Non-Solicitation. As a condition of your employment with the Company, you will be required to execute an Invention and Non-Disclosure Agreement and a Non-Competition and Non-Solicitation Agreement in the forms attached as Exhibit C and Exhibit D.

16.    Other Agreements. You represent that you are not bound by any employment contract, restrictive covenant or other restriction preventing you from entering into employment with or carrying out your responsibilities for the Company, or which is in any way inconsistent with the terms of this Agreement.

17.    Visa Status. The Company will file on your behalf and pay the cost of obtaining on an expedited basis an O-1 visa or other appropriate non-immigrant work visa. You will provide any and all assistance requested by the Company to expedite the filing of the O-1 or other appropriate non-immigrant work visa petition with the U.S. Citizenship and Immigration Service. Your employment with the Company will be conditioned upon your obtaining a valid work visa in a timely manner, as determined by the Company. The cost of reimbursements will be deemed imputed additional income to you to the extent required by applicable law.

18.    At-Will Employment. This Agreement shall not be construed as an agreement, either express or implied, to employ you for any stated term, and shall in no way alter the Company’s policy of employment at will, under which both you and the Company remain free to terminate the employment relationship for any reason or no reason, with or without cause, at any time, with or without notice.

19.    Company Policies and Procedures. As an employee of OvaScience, Limited and of the Company, you will be required to comply with all policies and procedures of the Company and its subsidiaries. Further, the Company’s premises, including all workspaces, furniture, documents and other tangible materials, and all information technology resources of the Company (including, but not limited to, computers, data and other electronic files, and all internet and e-mail systems) are subject to oversight and inspection by the Company at any time. Company employees should have no expectation of privacy with regard to any Company premises, materials, resources or information.

This Agreement, the Attachments and the Exhibits specifically referenced herein, constitute the entire agreement regarding the terms and conditions of your prospective employment with the Company. It supersedes any prior agreements, or other promises or statements (whether oral or written) regarding the offered terms of employment. The resolution of any disputes under this Agreement or related to your employment with or separation of employment from the Company shall be governed by the laws of the Commonwealth of Massachusetts, without regard to its or any other State’s conflict of laws rules that would otherwise require the application of another State’s laws. By accepting this offer of employment, you agree that any action, demand, claim or counterclaim in connection with any aspect of your employment with the Company, or any separation of employment (whether voluntary or involuntary) from the Company, shall be resolved exclusively in a Federal or State court of competent jurisdiction sitting in Massachusetts by a judge alone. You hereby consent to the exercise of personal jurisdiction of such courts over you, waive and forever renounce your right to a trial before a civil jury and waive and forever renounce the right to object to the exercise of jurisdiction by such courts on the grounds of inconvenient forum or improper venue. This Agreement shall be binding upon and shall inure to the benefit of the parties and their respective successors. This Agreement may only be amended in a writing signed by you and an authorized officer of the Company.

If this Agreement correctly sets forth the terms under which you will be employed by the Company, please sign in the space provided below and return it to Thomas Malley, Chair of the Compensation Committee.

A “Change in Control Event” shall be deemed to exist upon the sale of all or substantially all of the outstanding shares of capital stock, assets or business of the Company, by merger, consolidation, sale of assets or otherwise (other than a transaction in which all or substantially all of the individuals and entities who were beneficial owners of the capital stock of the Company immediately prior to such transaction beneficially own, directly or indirectly, more than 50% of the outstanding securities (on an as-converted to Common Stock basis) entitled to vote generally in the election of directors of the (i) resulting, surviving or acquiring corporation in such transaction in the case of a merger, consolidation or sale of outstanding shares, or (ii) acquiring corporation in the case of a sale of assets); provided that, in each of the foregoing cases, the Change in Control Event also meets all of the requirements of a “change in the ownership of a corporation” within the meaning of Treasury Regulation §1.409A-3(i)(5)(v) or “a change in the ownership of a substantial portion of the corporation’s assets” within in the meaning of Treasury Regulation §1.409A-3(i)(5)(vii).

“Disability” shall be deemed to exist if you are unable to perform the essential functions of the Company’s Chief Executive Officer, with or without a reasonable accommodation, for a period of one hundred twenty (120) calendar days, whether or not consecutive, within any rolling twelve (12) month period.

“Good Reason” shall be deemed to exist upon:

provided, however, that (i) no such event or condition shall constitute Good Reason unless (x) the employee gives the Company a written notice of termination for Good Reason not more than 90 days after the initial existence of the condition, (y) the grounds for termination if susceptible to correction are not corrected by the Company within 30 days of its receipt of such notice and (z) the employee’s termination of employment occurs within six months following the Company’s receipt of such notice; (ii) the employee acknowledges that there is an Executive Chair of the Company, and that the presence or influence of the Executive Chair, or the performance by the Executive Chair of certain duties that might otherwise be performed by the Chief Executive Officer of the Company, shall not be considered a material diminution in employee’s duties, authority or responsibilities; and (iii) at all times “Good Reason” will be interpreted in a manner consistent with the definition of “good reason” within the meaning of Section 409A (as defined below).

1.     Subject to this Exhibit B, payments or benefits during the Severance Period under the Agreement (“Severance Payments”) shall begin only upon the date of your “separation from service” (determined as set forth below) which occurs on or after the termination of your employment. The following rules shall apply with respect to distribution of the Severance Payments, as applicable:

2.    The determination of whether and when your separation from service from the Company has occurred shall be made in a manner consistent with, and based on the presumptions set forth in, Treasury Regulation Section 1.409A-1(h). Solely for purposes of this Exhibit B, Section 2, “Company” shall include all persons with whom the Company would be considered a single employer under Section 414(b) and 414(c) of the Code.

3.    All expense reimbursements shall be paid as soon as administratively practicable. If an expense reimbursement or provision of in-kind benefit is not exempt from Section 409A of the Code, the following rules apply: (i) in no event shall any reimbursement be paid after the last day of the taxable year following the taxable year in which the expense was incurred; (ii) the amount of reimbursable expenses incurred or provision of in-kind benefits in one tax year shall not affect the expenses eligible for reimbursement or the provision of in-kind benefits in any other tax year; and (iii) the right to reimbursement for expenses or provision of in-kind benefits is not subject to liquidation or exchange for any other benefit.

4.     The Company makes no representation or warranty and shall have no liability to you or to any other person if any of the provisions of the Agreement (including this Exhibit) are determined to constitute deferred compensation subject to Section 409A but that do not satisfy an exemption from, or the conditions of, that section.