EX-10.1



 Exhibit 10.1 

EVELO BIOSCIENCES, INC. 

2015 STOCK INCENTIVE PLAN 

(AS AMENDED THROUGH APRIL 27, 2018) 

 

	1.	Purpose 

 The purpose of this 2015 Stock Incentive Plan (the “Plan”) of
Evelo Biosciences, Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are expected
to make important contributions to the Company and by providing such persons with equity ownership opportunities and performance-based incentives that are intended to better align the interests of such persons with those of the Company’s
stockholders. Except where the context otherwise requires, the term “Company” shall include any of the Company’s present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Internal
Revenue Code of 1986, as amended, and any regulations thereunder (the “Code”) and any other business venture (including, without limitation, joint venture or limited liability company) in which the Company has a controlling
interest, as determined by the Board of Directors of the Company (the “Board”); provided, however, that such other business ventures shall be limited to entities that, where required by Section 409A of the Code,
are eligible issuers of service recipient stock (as defined in Treas. Reg. Section 1.409A-1(b)(5)(iii)(E), or applicable successor regulation). 

 

	2.	Eligibility 

 All of the Company’s employees, officers and directors, as well as
consultants and advisors to the Company (as such terms consultants and advisors are defined and interpreted for purposes of Rule 701 under the Securities Act of 1933, as amended (the “Securities Act”) (or any successor rule)) are
eligible to be granted Awards under the Plan. Each person who is granted an Award under the Plan is deemed a “Participant.” “Award” means Options (as defined in Section 5), SARs (as defined in Section 6),
Restricted Stock (as defined in Section 7), Restricted Stock Units (as defined in Section 7) and Other Stock-Based Awards (as defined in Section 8). 
  

	3.	Administration and Delegation 

 (a) Administration by the Board. The Plan will be
administered by the Board. The Board shall have authority to grant Awards and to adopt, amend and repeal such administrative rules, guidelines and practices relating to the Plan as it shall deem advisable. The Board may construe and interpret the
terms of the Plan and any Award agreements entered into under the Plan. The Board may correct any defect, supply any omission or reconcile any inconsistency in the Plan or any Award in the manner and to the extent it shall deem expedient to carry
the Plan into effect and it shall be the sole and final judge of such expediency. All decisions by the Board shall be made in the Board’s sole discretion and shall be final and binding on all persons having or claiming any interest in the Plan
or in any Award. 

  
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 (b) Appointment of Committees. To the extent permitted by applicable law, the Board may
delegate any or all of its powers under the Plan to one or more committees or subcommittees of the Board (each, a “Committee”). All references in the Plan to the “Board” shall mean the Board or a Committee of the
Board to the extent that the Board’s powers or authority under the Plan have been delegated to such Committee. 
  

	4.	Stock Available for Awards 

 (a) Number of Shares. Subject to adjustment under
Section 9, Awards may be made under the Plan for up to 5,417,044 shares of common stock, $0.001 par value per share, of the Company (the “Common Stock”), any or all of which Awards may be in the form of Incentive Stock Options
(as defined in Section 5(b)). If any Award expires or is terminated, surrendered or canceled without having been fully exercised, is forfeited in whole or in part (including as the result of shares of Common Stock subject to such Award being
repurchased by the Company at the original issuance price pursuant to a contractual repurchase right), or results in any Common Stock not being issued, the unused Common Stock covered by such Award shall again be available for the grant of Awards
under the Plan. Further, shares of Common Stock tendered to the Company by a Participant to exercise an Award or to satisfy tax withholding obligations arising with respect to an Award shall be added to the number of shares of Common Stock available
for the grant of Awards under the Plan. However, in the case of Incentive Stock Options, the two immediately preceding sentences shall be subject to any limitations under the Code. Shares issued under the Plan may consist in whole or in part of
authorized but unissued shares or treasury shares. 
 (b) Substitute Awards. In connection with a merger or consolidation of an entity
with the Company or the acquisition by the Company of property or stock of an entity, the Board may grant Awards in substitution for any options or other stock or stock-based awards granted by such entity or an affiliate thereof. Substitute Awards
may be granted on such terms as the Board deems appropriate in the circumstances, notwithstanding any limitations on Awards contained in the Plan. Substitute Awards shall not count against the overall share limit set forth in Section 4(a),
except as may be required by reason of Section 422 and related provisions of the Code. 
  

	5.	Stock Options 

 (a) General. The Board may grant options to purchase Common Stock
(each, an “Option”) and determine the number of shares of Common Stock to be covered by each Option, the exercise price of each Option and the conditions and limitations applicable to the exercise of each Option, including
conditions relating to applicable federal or state securities laws, as it considers necessary or advisable. 
 (b) Incentive Stock
Options. An Option that the Board intends to be an “incentive stock option” as defined in Section 422 of the Code (an “Incentive Stock Option”) shall only be granted to employees of Evelo Biosciences, Inc., any of
Evelo Biosciences, Inc.’s present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Code, and any other entities the employees of which are eligible to receive Incentive Stock Options under the Code,
and shall be subject to and shall be construed consistently with the requirements of Section 422 of the Code. An Option that is not intended to be an Incentive Stock Option shall be designated a “Nonstatutory Stock Option.” The
Company shall have no liability to a Participant, or any other party, if an Option (or any part thereof) that is intended to be an Incentive Stock Option is not an Incentive Stock Option or if the Company converts an Incentive Stock Option to a
Nonstatutory Stock Option. 

  
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 (c) Exercise Price. The Board shall establish the exercise price of each Option and
specify the exercise price in the applicable Option agreement. The exercise price shall be not less than 100% of the fair market value per share of Common Stock, as determined by (or in a manner approved by) the Board (“Fair Market
Value”), on the date the Option is granted. “Fair Market Value” of a share of Common Stock for purposes of the Plan will be determined as follows: 

(1) if the Common Stock is not publicly traded, the Board will determine the Fair Market Value for purposes of the Plan using any measure of
value it determines to be appropriate (including, as it considers appropriate, relying on appraisals) in a manner consistent with the valuation principles under Code Section 409A, except as the Board may expressly determine otherwise; 

(2) if the Common Stock trades on a national securities exchange, the closing sale price (for the primary trading session) on the date of
grant; or 
 (3) if the Common Stock does not trade on any such exchange, the average of the closing bid and asked prices as reported by an
authorized OTCBB market data vendor as listed on the OTCBB website (otcbb.com) on the date of grant. 
 For any date that is not a trading
day, the Fair Market Value of a share of Common Stock for such date will be determined by using the closing sale price or average of the bid and asked prices, as appropriate, for the immediately preceding trading day and with the timing in the
formulas above adjusted accordingly. The Board can substitute a particular time of day or other measure of “closing sale price” or “bid and asked prices” if appropriate because of exchange or market procedures or can, in its sole
discretion, use weighted averages either on a daily basis or such longer period as complies with Code Section 409A. 
 The Board has
sole discretion to determine the Fair Market Value for purposes of the Plan, and all Awards are conditioned on the participants’ agreement that the Administrator’s determination is conclusive and binding even though others might make a
different determination. 
 (d) Duration of Options. Each Option shall be exercisable at such times and subject to such terms and
conditions as the Board may specify in the applicable option agreement; provided, however, that no Option will be granted with a term in excess of 10 years. 

(e) Exercise of Options. Options may be exercised by delivery to the Company of a notice of exercise in a form of notice (which may be
electronic) approved by the Company, together with payment in full (in a manner specified in Section 5(f)) of the exercise price for the number of shares for which the Option is exercised. Shares of Common Stock subject to the Option will be
delivered by the Company as soon as practicable following exercise. 

  
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 (f) Payment upon Exercise. Common Stock purchased upon the exercise of an Option granted
under the Plan shall be paid for as follows: 
 (1) in cash or by check, payable to the order of the Company; 

(2) when the Common Stock is registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), except as
may otherwise be provided in the applicable Option agreement or approved by the Board, in its sole discretion, by (i) delivery of an irrevocable and unconditional undertaking by a creditworthy broker to deliver promptly to the Company
sufficient funds to pay the exercise price and any required tax withholding or (ii) delivery by the Participant to the Company of a copy of irrevocable and unconditional instructions to a creditworthy broker to deliver promptly to the Company
cash or a check sufficient to pay the exercise price and any required tax withholding; 
 (3) when the Common Stock is registered under the
Exchange Act and to the extent provided for in the applicable Option agreement or approved by the Board, in its sole discretion, by delivery (either by actual delivery or attestation) of shares of Common Stock owned by the Participant valued at
their Fair Market Value, provided (i) such method of payment is then permitted under applicable law, (ii) such Common Stock, if acquired directly from the Company, was owned by the Participant for such minimum period of time, if
any, as may be established by the Board in its discretion and (iii) such Common Stock is not subject to any repurchase, forfeiture, unfulfilled vesting or other similar requirements; 

(4) to the extent provided for in the applicable Nonstatutory Stock Option agreement or approved by the Board in its sole discretion, by
delivery of a notice of “net exercise” to the Company, as a result of which the Participant would pay the exercise price for the portion of the Option being exercised by cancelling a portion of the Option for such number of shares as is
equal to the exercise price divided by the excess of the Fair Market Value on the date of exercise over the Option exercise price per share. 

(5) to the extent permitted by applicable law and provided for in the applicable Option agreement or approved by the Board, in its sole
discretion, by (i) delivery of a promissory note of the Participant to the Company on terms determined by the Board, or (ii) payment of such other lawful consideration as the Board may determine; or 

(6) by any combination of the above permitted forms of payment. 

  
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	6.	Stock Appreciation Rights 

 (a) General. The Board may grant Awards consisting of
stock appreciation rights (“SARs”) entitling the holder, upon exercise, to receive an amount of Common Stock or cash or a combination thereof (such form to be determined by the Board) determined by reference to appreciation, from
and after the date of grant, in the Fair Market Value of a share of Common Stock over the measurement price established pursuant to Section 6(b). The date as of which such appreciation is determined shall be the exercise date. 

(b) Measurement Price. The Board shall establish the measurement price of each SAR and specify it in the applicable SAR agreement. The
measurement price shall not be less than 100% of the Fair Market Value on the date the SAR is granted. 
 (c) Duration of SARs. Each
SAR shall be exercisable at such times and subject to such terms and conditions as the Board may specify in the applicable SAR agreement; provided, however, that no SAR will be granted with a term in excess of 10 years. 

(d) Exercise of SARs. SARs may be exercised by delivery to the Company of a notice of exercise in a form (which may be electronic)
approved by the Company, together with any other documents required by the Board. 
  

	7.	Restricted Stock; Restricted Stock Units 

 (a) General. The Board may grant Awards
entitling recipients to acquire shares of Common Stock (“Restricted Stock”), subject to the right of the Company to repurchase all or part of such shares at their issue price or other stated or formula price (or to require
forfeiture of such shares if issued at no cost) from the recipient in the event that conditions specified by the Board in the applicable Award are not satisfied prior to the end of the applicable restriction period or periods established by the
Board for such Award. The Board may also grant Awards entitling the recipient to receive shares of Common Stock or cash to be delivered at the time such Award vests (“Restricted Stock Units”) (Restricted Stock and Restricted Stock
Units are each referred to herein as a “Restricted Stock Award”). 
 (b) Terms and Conditions for All Restricted Stock
Awards. The Board shall determine the terms and conditions of a Restricted Stock Award, including the conditions for vesting and repurchase (or forfeiture) and the issue price, if any. 

(c) Additional Provisions Relating to Restricted Stock. 

(1) Dividends. Unless otherwise provided in the applicable Award agreement, any dividends (whether paid in cash, stock or property)
declared and paid by the Company with respect to shares of Restricted Stock (“Accrued Dividends”) shall be paid to the Participant only if and when such shares become free from the restrictions on transferability and forfeitability
that apply to such shares. Each payment of Accrued Dividends will be made no later than the end of the calendar year in which the dividends are paid to stockholders of that class of stock or, if later, the 15th day of the third month following the
lapsing of the restrictions on transferability and the forfeitability provisions applicable to the underlying shares of Restricted Stock. 

  
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 (2) Stock Certificates. The Company may require that any stock certificates issued in
respect of shares of Restricted Stock, as well as dividends or distributions paid on such Restricted Stock, shall be deposited in escrow by the Participant, together with a stock power endorsed in blank, with the Company (or its designee). At the
expiration of the applicable restriction periods, the Company (or such designee) shall deliver the certificates no longer subject to such restrictions to the Participant or if the Participant has died, to Participant’s Designated Beneficiary.
“Designated Beneficiary” means (i) the beneficiary designated, in a manner determined by the Board, by a Participant to receive amounts due or exercise rights of the Participant in the event of the Participant’s death or
(ii) in the absence of an effective designation by a Participant, “Designated Beneficiary” the Participant’s estate. 

(d) Additional Provisions Relating to Restricted Stock Units. 

(1) Settlement. Upon the vesting of and/or lapsing of any other restrictions (i.e., settlement) with respect to each Restricted Stock
Unit, the Participant shall be entitled to receive from the Company one share of Common Stock or (if so provided in the applicable Award agreement) an amount of cash equal to the Fair Market Value of one share of Common Stock. The Board may, in its
discretion, provide that settlement of Restricted Stock Units shall be deferred, on a mandatory basis or at the election of the Participant in a manner that complies with Section 409A of the Code. 

(2) Voting Rights. A Participant shall have no voting rights with respect to any Restricted Stock Units. 

(3) Dividend Equivalents. The Award agreement for Restricted Stock Units may provide Participants with the right to receive an amount
equal to any dividends or other distributions declared and paid on an equal number of outstanding shares of Common Stock (“Dividend Equivalents”). Dividend Equivalents may be paid currently or credited to an account for the
Participants, may be settled in cash and/or shares of Common Stock and may be subject to the same restrictions on transfer and forfeitability as the Restricted Stock Units with respect to which paid, in each case to the extent provided in the
applicable Award agreement. 
  

	8.	Other Stock-Based Awards 

 (a) General. Other Awards of shares of Common Stock,
and other Awards that are valued in whole or in part by reference to, or are otherwise based on, shares of Common Stock or other property, may be granted hereunder to Participants (“Other Stock-Based-Awards”). Such Other Stock-Based
Awards shall also be available as a form of payment in the settlement of other Awards granted under the Plan or as payment in lieu of compensation to which a Participant is otherwise entitled. Other Stock-Based Awards may be paid in shares of Common
Stock or cash, as the Board shall determine. 
 (b) Terms and Conditions. Subject to the provisions of the Plan, the Board shall
determine the terms and conditions of each Other Stock-Based Award, including any purchase price applicable thereto. 

  
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	9.	Adjustments for Changes in Common Stock and Certain Other Events 

 (a) Changes in
Capitalization. In the event of any stock split, reverse stock split, stock dividend, recapitalization, combination of shares, reclassification of shares, spin-off or other similar change in capitalization
or event, or any dividend or distribution to holders of Common Stock other than an ordinary cash dividend, (i) the number and class of securities available under the Plan, (ii) the number and class of securities and exercise price per
share of each outstanding Option, (iii) the share and per-share provisions and the measurement price of each outstanding SAR, (iv) the number of shares subject to and the repurchase price per share
subject to each outstanding Restricted Stock Award and (v) the share and per-share-related provisions and the purchase price, if any, of each outstanding Other Stock-Based Award, shall be equitably
adjusted by the Company (or substituted Awards may be made, if applicable) in the manner determined by the Board. Without limiting the generality of the foregoing, in the event the Company effects a split of the Common Stock by means of a stock
dividend and the exercise price of and the number of shares subject to an outstanding Option are adjusted as of the date of the distribution of the dividend (rather than as of the record date for such dividend), then an optionee who exercises an
Option between the record date and the distribution date for such stock dividend shall be entitled to receive, on the distribution date, the stock dividend with respect to the shares of Common Stock acquired upon such Option exercise,
notwithstanding the fact that such shares were not outstanding as of the close of business on the record date for such stock dividend. 
 (b)
Reorganization Events. 
 (1) Definition. A “Reorganization Event” shall mean: (a) any merger or
consolidation of the Company with or into another entity as a result of which all of the Common Stock of the Company is converted into or exchanged for the right to receive cash, securities or other property or is cancelled, (b) any transfer or
disposition of all of the Common Stock of the Company for cash, securities or other property pursuant to a share exchange or other transaction or (c) any liquidation or dissolution of the Company. 

(2) Consequences of a Reorganization Event on Awards Other than Restricted Stock. 

(i) In connection with a Reorganization Event, the Board may take any one or more of the following actions as to all or any (or any portion
of) outstanding Awards other than Restricted Stock on such terms as the Board determines (except to the extent specifically provided otherwise in an applicable Award agreement or another agreement between the Company and the Participant):
(i) provide that such Awards shall be assumed, or substantially equivalent Awards shall be substituted, by the acquiring or succeeding corporation (or an affiliate thereof), (ii) upon written notice to a Participant, provide that all of
the Participant’s unexercised Awards will terminate immediately prior to the consummation of such Reorganization Event unless exercised by the Participant (to the extent then exercisable) within a specified period following the date of such
notice, (iii) provide that outstanding Awards shall become exercisable, realizable, or deliverable, or restrictions applicable to an Award shall lapse, in whole or in part prior to or upon such Reorganization Event, (iv) in the event of a
Reorganization Event under the terms of which holders of Common Stock will receive upon 

  
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consummation thereof a cash payment for each share surrendered in the Reorganization Event (the “Acquisition Price”), make or provide for a cash payment to Participants with
respect to each Award held by a Participant equal to (A) the number of shares of Common Stock subject to the vested portion of the Award (after giving effect to any acceleration of vesting that occurs upon or immediately prior to such
Reorganization Event) multiplied by (B) the excess, if any, of (I) the Acquisition Price over (II) the exercise, measurement or purchase price of such Award and any applicable tax withholdings, in exchange for the termination of such
Award, (v) provide that, in connection with a liquidation or dissolution of the Company, Awards shall convert into the right to receive liquidation proceeds (if applicable, net of the exercise, measurement or purchase price thereof and any
applicable tax withholdings) and (vi) any combination of the foregoing. In taking any of the actions permitted under this Section 9(b)(2), the Board shall not be obligated by the Plan to treat all Awards, all Awards held by a Participant,
or all Awards of the same type, identically. 
 (ii) Notwithstanding the terms of Section 9(b)(2)(i), in the case of outstanding
Restricted Stock Units that are subject to Section 409A of the Code: (i) if the applicable Restricted Stock Unit agreement provides that the Restricted Stock Units shall be settled upon a “change in control event” within the
meaning of Treasury Regulation Section 1.409A-3(i)(5)(i), and the Reorganization Event constitutes such a “change in control event”, then no assumption or substitution shall be permitted
pursuant to Section 9(b)(2)(i)(i) and the Restricted Stock Units shall instead be settled in accordance with the terms of the applicable Restricted Stock Unit agreement; and (ii) the Board may only undertake the actions set forth in
clauses (iii), (iv) or (v) of Section 9(b)(2)(i) if the Reorganization Event constitutes a “change in control event” as defined under Treasury Regulation Section 1.409A-3(i)(5)(i) and
such action is permitted or required by Section 409A of the Code; if the Reorganization Event is not a “change in control event” as so defined or such action is not permitted or required by Section 409A of the Code, and the
acquiring or succeeding corporation does not assume or substitute the Restricted Stock Units pursuant to clause (i) of Section 9(b)(2)(i), then the unvested Restricted Stock Units shall terminate immediately prior to the consummation of
the Reorganization Event without any payment in exchange therefor. 
 (iii) For purposes of Section 9(b)(2)(i)(i), an Award (other than
Restricted Stock) shall be considered assumed if, following consummation of the Reorganization Event, such Award confers the right to purchase or receive pursuant to the terms of such Award, for each share of Common Stock subject to the Award
immediately prior to the consummation of the Reorganization Event, the consideration (whether cash, securities or other property) received as a result of the Reorganization Event by holders of Common Stock for each share of Common Stock held
immediately prior to the consummation of the Reorganization Event (and if holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding shares of Common Stock); provided,
however, that if the consideration received as a result of the Reorganization Event is not solely common stock of the acquiring or succeeding corporation (or an affiliate thereof), the Company may, with the consent of the acquiring or succeeding
corporation, provide for the consideration to be received upon the exercise or settlement of the Award to consist solely of such number of shares of common stock of the acquiring or succeeding corporation (or an affiliate thereof) that the Board
determined to be equivalent in value (as of the date of such determination or another date specified by the Board) to the per share consideration received by holders of outstanding shares of Common Stock as a result of the Reorganization Event. 


  
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 (3) Consequences of a Reorganization Event on Restricted Stock. Upon the occurrence of a
Reorganization Event other than a liquidation or dissolution of the Company, the repurchase and other rights of the Company with respect to outstanding Restricted Stock shall inure to the benefit of the Company’s successor and shall, unless the
Board determines otherwise, apply to the cash, securities or other property which the Common Stock was converted into or exchanged for pursuant to such Reorganization Event in the same manner and to the same extent as they applied to such Restricted
Stock; provided, however, that the Board may provide for termination or deemed satisfaction of such repurchase or other rights under the instrument evidencing any Restricted Stock or any other agreement between a Participant and the
Company, either initially or by amendment. Upon the occurrence of a Reorganization Event involving the liquidation or dissolution of the Company, except to the extent specifically provided to the contrary in the instrument evidencing any Restricted
Stock or any other agreement between a Participant and the Company, all restrictions and conditions on all Restricted Stock then outstanding shall automatically be deemed terminated or satisfied. 

 

	10.	General Provisions Applicable to Awards. 

 (a) Transferability of Awards. Awards
(or any interest in an Award, including, prior to exercise, any interest in shares of Common Stock issuable upon exercise of an Option or SAR) shall not be sold, assigned, transferred (including by establishing any short position, put equivalent
position (as defined in Rule 16a-1 issued under the Exchange Act) or call equivalent position (as defined in Rule 16a-1 issued under the Exchange Act)), pledged,
hypothecated or otherwise encumbered by the person to whom they are granted, either voluntarily or by operation of law, and, during the life of the Participant, shall be exercisable only by the Participant; except that Awards, other than Awards
subject to Section 409A of the Code, may be transferred to family members (as defined in Rule 701(c)(3) under the Securities Act) through gifts or (other than Incentive Stock Options) domestic relations orders or to an executor or guardian upon
the death or disability of the Participant. The Company shall not be required to recognize any such permitted transfer until such time as such permitted transferee shall deliver to the Company a written instrument, as a condition to such transfer,
in form and substance satisfactory to the Company confirming that such transferee shall be bound by all of the terms and conditions of the Award. References to a Participant, to the extent relevant in the context, shall include references to
authorized transferees. For the avoidance of doubt, nothing contained in this Section 10(a) shall be deemed to restrict a transfer to the Company. 

(b) Documentation. Each Award shall be evidenced in such form (written, electronic or otherwise) as the Board shall determine. Each
Award may contain terms and conditions in addition to those set forth in the Plan. 
 (c) Board Discretion. Except as otherwise
provided by the Plan, each Award may be made alone or in addition or in relation to any other Award. The terms of each Award need not be identical, and the Board need not treat Participants uniformly. 

  
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 (d) Termination of Status. The Board shall determine the effect on an Award of the
disability, death, termination or other cessation of employment, authorized leave of absence or other change in the employment or other status of a Participant and the extent to which, and the period during which, the Participant, or the
Participant’s legal representative, conservator, guardian or Designated Beneficiary, may exercise rights under the Award.  

(e) Withholding. The Participant must satisfy all applicable federal, state, and local or other income and employment tax withholding
obligations before the Company will deliver stock certificates or otherwise recognize ownership of Common Stock under an Award. The Company may decide to satisfy the withholding obligations through additional withholding on salary or wages. If the
Company elects not to or cannot withhold from other compensation, the Participant must pay the Company the full amount, if any, required for withholding or have a broker tender to the Company cash equal to the withholding obligations. Payment of
withholding obligations is due before the Company will issue any shares on exercise, vesting or release from forfeiture of an Award or at the same time as payment of the exercise or purchase price unless the Company determines otherwise. If provided
for in an Award or approved by the Board in its sole discretion, a Participant may satisfy such tax obligations in whole or in part by delivery (either by actual delivery or attestation) of shares of Common Stock, including shares retained from the
Award creating the tax obligation, valued at their Fair Market Value; provided, however, except as otherwise provided by the Board, that the total tax withholding where stock is being used to satisfy such tax obligations cannot exceed the
Company’s minimum statutory withholding obligations (based on minimum statutory withholding rates for federal and state tax purposes, including payroll taxes, that are applicable to such supplemental taxable income). Shares used to satisfy tax
withholding requirements cannot be subject to any repurchase, forfeiture, unfulfilled vesting or other similar requirements. 
 (f)
Amendment of Award. 
 (1) The Board may amend, modify or terminate any outstanding Award, including but not limited to, substituting
therefor another Award of the same or a different type, changing the date of exercise or realization, and converting an Incentive Stock Option to a Nonstatutory Stock Option. The Participant’s consent to such action shall be required unless
(i) the Board determines that the action, taking into account any related action, does not materially and adversely affect the Participant’s rights under the Plan or (ii) the change is permitted under Section 9. 

(2) The Board may, without stockholder approval, amend any outstanding Award granted under the Plan to provide an exercise price per share that
is lower than the then-current exercise price per share of such outstanding Award. The Board may also, without stockholder approval, cancel any outstanding award (whether or not granted under the Plan) and grant in substitution therefor new Awards
under the Plan covering the same or a different number of shares of Common Stock and having an exercise price per share lower than the then-current exercise price per share of the cancelled award. 

  
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 (g) Conditions on Delivery of Stock. The Company will not be obligated to deliver any
shares of Common Stock pursuant to the Plan or to remove restrictions from shares previously issued or delivered under the Plan until (i) all conditions of the Award have been met or removed to the satisfaction of the Company, (ii) in the
opinion of the Company’s counsel, all other legal matters in connection with the issuance and delivery of such shares have been satisfied, including any applicable securities laws and regulations and any applicable stock exchange or stock
market rules and regulations, and (iii) the Participant has executed and delivered to the Company such representations or agreements as the Company may consider appropriate to satisfy the requirements of any applicable laws, rules or
regulations. 
 (h) Acceleration. The Board may at any time provide that any Award shall become immediately exercisable in whole or in
part, free of some or all restrictions or conditions, or otherwise realizable in whole or in part, as the case may be. 
  

	11.	Miscellaneous. 

 (a) No Right to Employment or Other Status. No person shall have
any claim or right to be granted an Award by virtue of the adoption of the Plan, and the grant of an Award shall not be construed as giving a Participant the right to continued employment or any other relationship with the Company. The Company
expressly reserves the right at any time to dismiss or otherwise terminate its relationship with a Participant free from any liability or claim under the Plan, except as expressly provided in the applicable Award. 

(b) No Rights as Stockholder. Subject to the provisions of the applicable Award, no Participant or Designated Beneficiary shall have any
rights as a stockholder with respect to any shares of Common Stock to be distributed with respect to an Award until becoming the record holder of such shares. 

(c) Effective Date and Term of Plan. The Plan shall become effective on the date on which it is adopted by the Board. No Awards shall be
granted under the Plan after the expiration of 10 years from the earlier of (i) the date on which the Plan was adopted by the Board or (ii) the date the Plan was approved by the Company’s stockholders, but Awards previously granted
may extend beyond that date. 
 (d) Amendment of Plan. The Board may amend, suspend or terminate the Plan or any portion thereof at
any time; provided that if at any time the approval of the Company’s stockholders is required as to any modification or amendment under Section 422 of the Code or any successor provision with respect to Incentive Stock Options, the
Board may not effect such modification or amendment without such approval. Unless otherwise specified in the amendment, any amendment to the Plan adopted in accordance with this Section 11(d) shall apply to, and be binding on the holders of,
all Awards outstanding under the Plan at the time the amendment is adopted, provided the Board determines that such amendment, taking into account any related action, does not materially and adversely affect the rights of Participants under the
Plan. 
 (e) Authorization of Sub-Plans (including Grants to
non-U.S. Employees). The Board may from time to time establish one or more sub-plans under the Plan for purposes of satisfying applicable securities, tax or other
laws of various jurisdictions. The Board shall establish such sub-plans by adopting supplements to the Plan containing (i) such limitations on the Board’s discretion under the Plan as the Board deems
necessary or desirable or (ii) such 

  
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additional terms and conditions not otherwise inconsistent with the Plan as the Board shall deem necessary or desirable. All supplements adopted by the Board shall be deemed to be part of the
Plan, but each supplement shall apply only to Participants within the affected jurisdiction and the Company shall not be required to provide copies of any supplement to Participants in any jurisdiction which is not the subject of such supplement.

 (f) Compliance with Section 409A of the Code. Except as provided in individual Award agreements initially or by
amendment, if and to the extent (i) any portion of any payment, compensation or other benefit provided to a Participant pursuant to the Plan in connection with Participant’s employment termination constitutes “nonqualified deferred
compensation” within the meaning of Section 409A of the Code and (ii) the Participant is a specified employee as defined in Section 409A(a)(2)(B)(i) of the Code, in each case as determined by the Company in accordance with its
procedures, by which determinations the Participant (through accepting the Award) agrees that the Participant is bound, such portion of the payment, compensation or other benefit shall not be paid before the day that is six months plus one
day after the date of “separation from service” (as determined under Section 409A of the Code) (the “New Payment Date”), except as Section 409A of the Code may then permit. The aggregate of any payments that
otherwise would have been paid to the Participant during the period between the date of separation from service and the New Payment Date shall be paid to the Participant in a lump sum on such New Payment Date, and any remaining payments will be paid
on their original schedule. 
 The Company makes no representations or warranty and shall have no liability to the Participant or any other person if any
provisions of or payments, compensation or other benefits under the Plan are determined to constitute nonqualified deferred compensation subject to Section 409A of the Code but do not to satisfy the conditions of that section. 

(g) Limitations on Liability. Notwithstanding any other provisions of the Plan, no individual acting as a director,
officer, other employee, or agent of the Company will be liable to any Participant, former Participant, spouse, beneficiary, or any other person for any claim, loss, liability, or expense incurred in connection with the Plan, nor will such
individual be personally liable with respect to the Plan because of any contract or other instrument such individual executes in such individual’s capacity as a director, officer, other employee, or agent of the Company. The Company will
indemnify and hold harmless each director, officer, other employee, or agent of the Company to whom any duty or power relating to the administration or interpretation of the Plan has been or will be delegated, against any cost or expense (including
attorneys’ fees) or liability (including any sum paid in settlement of a claim with the Board’s approval) arising out of any act or omission to act concerning the Plan unless arising out of such person’s own fraud or bad faith. 

(h) Governing Law. The provisions of the Plan and all Awards made hereunder shall be governed by and interpreted in accordance with the
laws of the State of Delaware, excluding choice-of-law principles of the law of such state that would require the application of the laws of a jurisdiction other than
the State of Delaware. 
 * * * * 

  
 12 








 EVELO BIOSCIENCES, INC. 

2015 STOCK INCENTIVE PLAN 

CALIFORNIA SUPPLEMENT 

Pursuant to Section 11(e) of the Plan, the Board has adopted this supplement for purposes of satisfying the requirements of
Section 25102(o) of the California Law: 
 Any Awards granted under the Plan to a Participant who is a resident of the State of
California on the date of grant (a “California Participant”) shall be subject to the following additional limitations, terms and conditions: 

1. Additional Limitations on Options. 

(a) Maximum Duration of Options. No Options granted to California Participants shall have a term in excess of 10 years measured from the
Option grant date. 
 (b) Minimum Exercise Period Following Termination. Unless a California Participant’s employment is
terminated for cause (as defined by applicable law, the terms of the Plan or option grant or a contract of employment), in the event of termination of employment of such Participant, such Participant shall have the right to exercise an Option, to
the extent that such Participant is entitled to exercise such Option on the date employment terminated, until the earlier of: (i) at least six months from the date of termination, if termination was caused by such Participant’s death or
disability, (ii) at least 30 days from the date of termination, if termination was caused other than by such Participant’s death or disability and (iii) the Option expiration date. 

2. Additional Limitations for Other Stock-Based Awards. The terms of all Awards granted to a California Participant under Section 8 of the Plan
shall comply, to the extent applicable, with Sections 260.140.42, 260.140.45 and 260.140.46 of the California Code of Regulations. 
 3. Additional
Limitations on Timing of Awards. No Award granted to a California Participant shall become exercisable, vested or realizable, as applicable to such Award, unless the Plan has been approved by the holders of a majority of the Company’s
outstanding voting securities by the later of (i) within 12 months before or after the date the Plan was adopted by the Board, or (ii) prior to or within 12 months of the granting of any Award to a California Participant. 

4. Additional Restriction Regarding Recapitalizations, Stock Splits, Etc. For purposes of Section 9 of the Plan, in the event of a stock split,
reverse stock split, stock dividend, recapitalization, combination, reclassification or other distribution of the Company’s securities underlying the Award without the receipt of consideration by the Company, the number of securities
purchasable, and in the case of Options, the exercise price of such Options, must be proportionately adjusted. 
 5. Additional Limitations on
Transferability of Awards. Notwithstanding the provisions of Section 10(a) of the Plan, an Award granted to a California Participant may not be transferred to an executor or guardian upon the disability of the Participant. 

* * * * 

  
 13 








 EVELO BIOSCIENCES, INC. 

NONSTATUTORY STOCK OPTION AGREEMENT 

GRANTED UNDER 2015 STOCK INCENTIVE PLAN 

 

	1.	Grant of Option. 

 This Nonstatutory Stock Option Agreement (the
“Agreement”) evidences the grant by Evelo Biosciences, Inc., a Delaware corporation (the “Company”), on [                ,
20        ] (the “Grant Date”) to [                    ], an employee, consultant or
director of the Company (the “Participant”), of an option to purchase, in whole or in part, on the terms provided herein and in the Company’s 2015 Stock Incentive Plan (the “Plan”), a total of
[                    ] shares (the “Shares”) of common stock, $0.001 par value per share, of the Company (“Common
Stock”) at $[                    ] per Share. Unless earlier terminated, this option shall expire at 5:00 p.m., Eastern time, on
[                , 20        ] [date is ten years minus one day from grant date] (the “Final Exercise Date”).

 It is intended that the option evidenced by this Agreement shall not be an incentive stock option as defined in Section 422 of the
Internal Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the “Code”). Except as otherwise indicated by the context, the term “Participant”, as used in this option, shall be deemed to
include any person who acquires the right to exercise this option validly under its terms. 
  

	2.	Vesting Schedule. 

 This option will become exercisable (“vest”) as to
25% of the original number of Shares on the first anniversary of the Vesting Commencement Date (as defined below) and as to an additional 6.25% of the original number of Shares at the end of each successive quarter following the first
anniversary of the Vesting Commencement Date until the fourth anniversary of the Vesting Commencement Date. On the fourth anniversary of the Vesting Commencement Date, this option will be exercisable as to all Shares. For purposes of this Agreement,
“Vesting Commencement Date” shall mean [                            ]. 

The right of exercise shall be cumulative so that to the extent the option is not exercised in any period to the maximum extent permissible it
shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or the termination of this option under Section 3 hereof or the Plan. 

 

	3.	Exercise of Option. 

 (a) Form of Exercise. Each election to exercise this option
shall be accompanied by a completed Notice of Stock Option Exercise in the form attached hereto as Exhibit A, signed by the Participant, and received by the Company at its principal office, accompanied by this Agreement, and payment in full
in the manner provided in the Plan. The Participant may purchase less than the number of Shares covered hereby, provided that no partial exercise of this option may be for any fractional share or for fewer than ten whole shares. 







 (b) Continuous Relationship with the Company Required. Except as otherwise provided in
this Section 3, this option may not be exercised unless the Participant, at the time he or she exercises this option, is, and has been at all times since the Grant Date, an employee, officer or director 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 option grants under the Plan (an “Eligible Participant”). 

(c) Termination of Relationship with the Company. If the Participant ceases to be an Eligible Participant for any reason, then, except
as provided in paragraphs (d) and (e) below, the right to exercise this option shall terminate three months after such cessation (but in no event after the Final Exercise Date), provided that this option shall be exercisable
only to the extent that the Participant was entitled to exercise this option on the date of such cessation. Notwithstanding the foregoing, if the Participant, prior to the Final Exercise Date, violates the
non-competition or confidentiality provisions of any employment contract, confidentiality and nondisclosure agreement or other agreement between the Participant and the Company, the right to exercise this
option shall terminate immediately upon such violation. 
 (d) Exercise Period Upon Death or Disability. If the Participant dies or
becomes disabled (within the meaning of Section 22(e)(3) of the Code) prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for “cause” as specified in
paragraph (e) below, this option shall be exercisable, within the period of one year following the date of death or disability of the Participant, by the Participant (or in the case of death by an authorized transferee), provided
that this option shall be exercisable only to the extent that this option was exercisable by the Participant on the date of his or her death or disability, and further provided that this option shall not be exercisable after the Final
Exercise Date. 
 (e) Termination for Cause. If, prior to the Final Exercise Date, the Participant’s employment or other
relationship with the Company is terminated by the Company for Cause (as defined below), the right to exercise this option shall terminate immediately upon the effective date of such termination of employment or other relationship. If, prior to the
Final Exercise Date, the Participant is given notice by the Company of the termination of his or her employment or other relationship by the Company for Cause, and the effective date of such employment or other termination is subsequent to the date
of the delivery of such notice, the right to exercise this option shall be suspended from the time of the delivery of such notice until the earlier of (i) such time as it is determined or otherwise agreed that the Participant’s employment
or other relationship shall not be terminated for Cause as provided in such notice or (ii) the effective date of such termination of employment or other relationship (in which case the right to exercise this option shall, pursuant to the
preceding sentence, terminate immediately upon the effective date of such termination of employment or other relationship). If the Participant is party to an employment, consulting or severance agreement with the Company that contains a definition
of “cause” for termination of employment or other relationship, “Cause” shall have the meaning ascribed to such term in such agreement. Otherwise, “Cause” shall mean willful misconduct by the Participant or willful
failure by the Participant to perform his or her responsibilities to the Company (including, without limitation, breach by the Participant of any provision of any employment, consulting, advisory, nondisclosure,
non-competition or other similar agreement between the Participant and the Company), as determined by the Company, which determination shall be conclusive. The Participant’s employment or other
relationship shall be considered to have been terminated for “Cause” if the Company determines, within 30 days after the Participant’s resignation, that termination for Cause was warranted. 

  
 -2- 









	4.	Company Right of First Refusal. 

 (a) Notice of Proposed Transfer. If the
Participant proposes to sell, assign, transfer, pledge, hypothecate or otherwise dispose of, by operation of law or otherwise (collectively, “transfer”) any Shares acquired upon exercise of this option, then the Participant shall first
give written notice of the proposed transfer (the “Transfer Notice”) to the Company. The Transfer Notice shall name the proposed transferee and state the number of such Shares the Participant proposes to transfer (the
“Offered Shares”), the price per share and all other material terms and conditions of the transfer. 
 (b) Company Right
to Purchase. For 30 days following its receipt of such Transfer Notice, the Company shall have the option to purchase all or part of the Offered Shares at the price and upon the terms set forth in the Transfer Notice. In the event the Company
elects to purchase all or part of the Offered Shares, it shall give written notice of such election to the Participant within such 30-day period. Within 10 days after his or her receipt of such notice, the
Participant shall tender to the Company at its principal offices the certificate or certificates representing the Offered Shares to be purchased by the Company, duly endorsed in blank by the Participant or with duly endorsed stock powers attached
thereto, all in a form suitable for transfer of the Offered Shares to the Company. Promptly following receipt of such certificate or certificates, the Company shall deliver or mail to the Participant a check in payment of the purchase price for such
Offered Shares; provided that if the terms of payment set forth in the Transfer Notice were other than cash against delivery, the Company may pay for the Offered Shares on the same terms and conditions as were set forth in the Transfer
Notice; and provided further that any delay in making such payment shall not invalidate the Company’s exercise of its option to purchase the Offered Shares. 

(c) Shares Not Purchased By Company. If the Company does not elect to acquire all of the Offered Shares, the Participant may, within the
30-day period following the expiration of the option granted to the Company under subsection (b) above, transfer the Offered Shares which the Company has not elected to acquire to the proposed transferee,
provided that such transfer shall not be on terms and conditions more favorable to the transferee than those contained in the Transfer Notice. Notwithstanding any of the above, all Offered Shares transferred pursuant to this
Section 4 shall remain subject to the right of first refusal set forth in this Section 4 and such transferee shall, as a condition to such transfer, deliver to the Company a written instrument confirming that such transferee shall be bound
by all of the terms and conditions of this Section 4. 
 (d) Consequences of
Non-Delivery. After the time at which the Offered Shares are required to be delivered to the Company for transfer to the Company pursuant to subsection (b) above, the Company shall not pay any
dividend to the Participant on account of such Offered Shares or permit the Participant to exercise any of the privileges or rights of a stockholder with respect to such Offered Shares, but shall, insofar as permitted by law, treat the Company as
the owner of such Offered Shares. 

  
 -3- 








 (e) Exempt Transactions. The following transactions shall be exempt from the provisions of
this Section 4: 
 (1) any transfer of Shares to or for the benefit of any spouse, child or grandchild of the Participant, or to a trust
for their benefit; 
 (2) any transfer pursuant to an effective registration statement filed by the Company under the Securities Act of 1933,
as amended (the “Securities Act”); and 
 (3) the sale of all or substantially all of the outstanding shares of capital
stock of the Company (including pursuant to a merger or consolidation); 
 provided, however, that in the case of a transfer
pursuant to clause (1) above, such Shares shall remain subject to the right of first refusal set forth in this Section 4. 
 (f)
Assignment of Company Right. The Company may assign its rights to purchase Offered Shares in any particular transaction under this Section 4 to one or more persons or entities. 

(g) Termination. The provisions of this Section 4 shall terminate upon the earlier of the following events: 

(1) the closing of the sale of shares of Common Stock in an underwritten public offering pursuant to an effective registration statement filed
by the Company under the Securities Act; or 
 (2) 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 merger or consolidation in which all or substantially all of the individuals and entities who were beneficial owners of the Company’s voting securities
immediately prior to such transaction beneficially own, directly or indirectly, more than 75% (determined on an as-converted basis) of the outstanding securities entitled to vote generally in the election of
directors of the resulting, surviving or acquiring corporation in such transaction). 
 (h) No Obligation to Recognize Invalid
Transfer. The Company shall not be required (1) to transfer on its books any of the Shares which shall have been sold or transferred in violation of any of the provisions set forth in this Section 4, or (2) to treat as owner of
such Shares or to pay dividends to any transferee to whom any such Shares shall have been so sold or transferred. 
 (i) Legends. The
certificate representing Shares shall bear a legend substantially in the following form (in addition to, or in combination with, any legend required by applicable federal and state securities laws and agreements relating to the transfer of the
Company securities): 
 “The shares represented by this certificate are subject to a right of first refusal in favor of the Company, as
provided in a certain stock option agreement with the Company.” 

  
 -4- 









	5.	Agreement in Connection with Initial Public Offering. 

 The Participant agrees, in
connection with the initial underwritten public offering of the Common Stock pursuant to a registration statement under the Securities Act, (i) not to (a) offer, pledge, announce the intention to sell, sell, contract to sell, sell any
option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any other securities of the Company
or (b) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of shares of Common Stock or other securities of the Company, whether any transaction described in clause
(a) or (b) is to be settled by delivery of securities, in cash or otherwise, during the period beginning on the date of the filing of such registration statement with the Securities and Exchange Commission and ending 180 days after the date of
the final prospectus relating to the offering (plus up to an additional 34 days to the extent requested by the managing underwriters for such offering in order to address FINRA Rule 2241 or NYSE Rule 472(f)(4) or any similar successor provision),
and (ii) to execute any agreement reflecting clause (i) above as may be requested by the Company or the managing underwriters at the time of such offering. The Company may impose stop-transfer instructions with respect to the shares of
Common Stock or other securities subject to the foregoing restriction until the end of the “lock-up” period. 
  

	6.	Withholding. 

 No Shares will be issued pursuant to the exercise of this option unless
and until the Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes required by law to be withheld in respect of this option. 

 

	7.	Transfer Restrictions. 

 (a) This option may not be sold, assigned, transferred, pledged
or otherwise encumbered by the Participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution, and, during the lifetime of the Participant, this option shall be exercisable only by the Participant.  
 (b) The Participant agrees that he or she will not transfer any Shares issued pursuant
to the exercise of this option unless the transferee, as a condition to such transfer, delivers to the Company a written instrument confirming that such transferee shall be bound by all of the terms and conditions of Section 4 and
Section 5; provided that such a written confirmation shall not be required with respect to (1) Section 4 after such provision has terminated in accordance with Section 4(g) or (2) Section 5 after the completion of the lock-up period in connection with the Company’s initial underwritten public offering. 

  
 -5- 









	8.	Provisions of the Plan. 

 This option is subject to the provisions of the Plan (including
the provisions relating to amendments to the Plan), a copy of which is furnished to the Participant with this option. Participant hereby agrees to execute such further instruments and to take such further action as the Company requests to carry out
the purposes and intent of the Plan, including, without limitation, restrictions on the transferability of shares of Common Stock, the right of the Company to repurchase shares of Common Stock, the right of the Company to require that shares of
Common Stock be transferred in the event of certain transactions, tag-along rights, bring-along rights, redemption and co-sale rights and voting requirements. 

[Remainder of Page Intentionally Left Blank] 

  
 -6- 








 IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day and year first
above written. The Participant hereby accepts the foregoing option and agrees to the terms and conditions thereof. The Participant hereby acknowledges receipt of a copy of the Company’s 2015 Stock Incentive Plan. 

 

			
	COMPANY:
	
	Evelo Biosciences, Inc.
		
	By:	 	  

		 	Name:                                     
                       
		 	Title:                                     
                         
	
	PARTICIPANT:
		
	By:	 	  

		 	[Name]


 
			
		
	Address:	 	[                                      
                               ]
		 	[                                      
                               ]
	
	SPOUSAL CONSENT:1


 
			
		
	By:	 	  

		 	Name:                                     
                       


 
			
		
	Address:	 	[                                      
                               ]
		 	[                                      
                               ]


  

	1 	If the Participant resides in a community property state, it is desirable to have the Participant’s spouse also accept the option. The following are community property states: Arizona, California, Idaho, Louisiana,
Nevada, New Mexico, Texas, and Washington. Although Wisconsin is not formally a community property state, it has laws governing the division of marital property similar to community property states and it may be desirable to have a Wisconsin
Participant’s spouse accept the option. 

 SIGNATURE PAGE TO NONSTATUTORY STOCK OPTION AGREEMENT 







 EXHIBIT A 

NOTICE OF STOCK OPTION EXERCISE 

[DATE]1 

Evelo Biosciences, Inc. 
 One Memorial Drive 

Cambridge, MA 02142 
 Attention: Treasurer 

Dear Sir or Madam: 
 I am the holder of a
Nonstatutory Stock Option granted to me under the Evelo Biosciences, Inc. (the “Company”) 2015 Stock Incentive Plan on
[                    ]2 for the purchase of
[                    ]3 shares of Common Stock of the Company at a purchase price of
$[                    ]4 per share. 

I hereby exercise my option to purchase
[                    ]5 shares of Common Stock (the “Shares”), for which I have
enclosed [                    ]6 in the amount of
[                    ]7. Please register my stock certificate as follows: 

 

							
	 Name(s):
	 		  	 8
	  	
				
		 		  	 	  	
				
	Address:	 		  	 	  	
				
		 		  	 	  	


  

	1 	Enter date of exercise. 


	2 	Enter the date of grant. 


	3 	Enter the total number of shares of Common Stock for which the option was granted. 


	4 	Enter the option exercise price per share of Common Stock. 


	5 	Enter the number of shares of Common Stock to be purchased upon exercise of all or part of the option. 


	6 	Enter “cash”, “personal check” or if permitted by the option or Plan, “stock certificates No. XXXX and XXXX”. 


	7 	Enter the dollar amount (price per share of Common Stock times the number of shares of Common Stock to be purchased), or the number of shares tendered. Fair market value of shares tendered, together with cash or check,
must cover the purchase price of the shares issued upon exercise. 


	8 	Enter name(s) to appear on stock certificate in one of the following formats: (a) your name only (i.e., John Doe); (b) your name and other name (i.e., John Doe and Jane Doe, Joint Tenants with Right to Survivorship); or
for Nonstatutory Stock Options only, (c) a child’s name, with you as custodian (i.e. Jane Doe, Custodian for Tommy Doe). Note: There may be income and/or gift tax consequences for registering shares in a child’s name. 


	








 I represent, warrant and covenant as follows: 

1. I am purchasing the Shares for my own account for investment only, and not with a view to, or for sale in connection with, any distribution of the Shares in
violation of the Securities Act of 1933 (the “Securities Act”), or any rule or regulation under the Securities Act. 
 2. I have had such
opportunity as I have deemed adequate to obtain from representatives of the Company such information as is necessary to permit me to evaluate the merits and risks of my investment in the Company. 

3. I have sufficient experience in business, financial and investment matters to be able to evaluate the risks involved in the purchase of the Shares and to
make an informed investment decision with respect to such purchase. 
 4. I can afford a complete loss of the value of the Shares and am able to bear the
economic risk of holding such Shares for an indefinite period. 
 5. I understand that (i) the Shares have not been registered under the Securities Act
and are “restricted securities” within the meaning of Rule 144 under the Securities Act, (ii) the Shares cannot be sold, transferred or otherwise disposed of unless they are subsequently registered under the Securities Act or an
exemption from registration is then available; (iii) in any event, the exemption from registration under Rule 144 will not be available for at least one year and even then will not be available unless a public market then exists for the Common
Stock, adequate information concerning the Company is then available to the public, and other terms and conditions of Rule 144 are complied with; and (iv) there is now no registration statement on file with the Securities and Exchange
Commission with respect to any stock of the Company and the Company has no obligation or current intention to register the Shares under the Securities Act. 
  

	
	
	Very truly yours,
	
	                                      
                      
	[Name]


  
 -9- 








 EVELO BIOSCIENCES, INC. 

INCENTIVE STOCK OPTION AGREEMENT 

GRANTED UNDER 2015 STOCK INCENTIVE PLAN 

 

	1.	Grant of Option. 

 This Incentive Stock Option Agreement (the
“Agreement”) evidences the grant by Evelo Biosciences, Inc., a Delaware corporation (the “Company”), on
[                    , 20        ] (the “Grant Date”) to
[                    ], an employee of the Company (the “Participant”), of an option to purchase, in whole or in part, on the terms
provided herein and in the Company’s 2015 Stock Incentive Plan (the “Plan”), a total of [                    ] shares (the
“Shares”) of common stock, $0.001 par value per share, of the Company (“Common Stock”) at
$[                    ] per Share. Unless earlier terminated, this option shall expire at 5:00 p.m., Eastern time, on
[                    , 20        ] [date is ten years minus one day from grant date] (the
“Final Exercise Date”). 
 It is intended that the option evidenced by this Agreement shall be an incentive stock option as
defined in Section 422 of the Internal Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the “Code”). Except as otherwise indicated by the context, the term “Participant”, as used in
this option, shall be deemed to include any person who acquires the right to exercise this option validly under its terms. 
  

	2.	Vesting Schedule. 

 This option will become exercisable (“vest”) as to
25% of the original number of Shares on the first anniversary of the Vesting Commencement Date (as defined below) and as to an additional 6.25% of the original number of Shares at the end of each successive quarter following the first
anniversary of the Vesting Commencement Date until the fourth anniversary of the Vesting Commencement Date. On the fourth anniversary of the Vesting Commencement Date, this option will be exercisable as to all Shares. For purposes of this Agreement,
“Vesting Commencement Date” shall mean
[                                ]. 

The right of exercise shall be cumulative so that to the extent the option is not exercised in any period to the maximum extent permissible it
shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or the termination of this option under Section 3 hereof or the Plan. 

 

	3.	Exercise of Option. 

 (a) Form of Exercise. Each election to exercise this option
shall be accompanied by a completed Notice of Stock Option Exercise in the form attached hereto as Exhibit A, signed by the Participant, and received by the Company at its principal office, accompanied by this Agreement, and payment in full
in the manner provided in the Plan. The Participant may purchase less than the number of Shares covered hereby, provided that no partial exercise of this option may be for any fractional share or for fewer than ten whole shares. 







 (b) Continuous Relationship with the Company Required. Except as otherwise provided in
this Section 3, this option may not be exercised unless the Participant, at the time he or she exercises this option, is, and has been at all times since the Grant Date, an employee or officer of, or consultant or advisor to, the Company or any
parent or subsidiary of the Company as defined in Section 424(e) or (f) of the Code (an “Eligible Participant”). 

(c) Termination of Relationship with the Company. If the Participant ceases to be an Eligible Participant for any reason, then, except
as provided in paragraphs (d) and (e) below, the right to exercise this option shall terminate three months after such cessation (but in no event after the Final Exercise Date), provided that this option shall be
exercisable only to the extent that the Participant was entitled to exercise this option on the date of such cessation. Notwithstanding the foregoing, if the Participant, prior to the Final Exercise Date, violates the
non-competition or confidentiality provisions of any employment contract, confidentiality and nondisclosure agreement or other agreement between the Participant and the Company, the right to exercise this
option shall terminate immediately upon such violation. 
 (d) Exercise Period Upon Death or Disability. If the Participant dies or
becomes disabled (within the meaning of Section 22(e)(3) of the Code) prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for “cause” as specified in
paragraph (e) below, this option shall be exercisable, within the period of one year following the date of death or disability of the Participant, by the Participant (or in the case of death by an authorized transferee), provided
that this option shall be exercisable only to the extent that this option was exercisable by the Participant on the date of his or her death or disability, and further provided that this option shall not be exercisable after the Final
Exercise Date. 
 (e) Termination for Cause. If, prior to the Final Exercise Date, the Participant’s employment is terminated by
the Company for Cause (as defined below), the right to exercise this option shall terminate immediately upon the effective date of such termination of employment. If, prior to the Final Exercise Date, the Participant is given notice by the Company
of the termination of his or her employment by the Company for Cause, and the effective date of such employment termination is subsequent to the date of delivery of such notice, the right to exercise this option shall be suspended from the time of
the delivery of such notice until the earlier of (i) such time as it is determined or otherwise agreed that the Participant’s employment shall not be terminated for Cause as provided in such notice or (ii) the effective date of such
termination of employment (in which case the right to exercise this option shall, pursuant to the preceding sentence, terminate upon the effective date of such termination of employment). If the Participant is party to an employment or severance
agreement with the Company that contains a definition of “cause” for termination of employment, “Cause” shall have the meaning ascribed to such term in such agreement. Otherwise, “Cause” shall mean willful misconduct by
the Participant or willful failure by the Participant to perform his or her responsibilities to the Company (including, without limitation, breach by the Participant of any provision of any employment, consulting, advisory, nondisclosure, non-competition or other similar agreement between the Participant and the Company), as determined by the Company, which determination shall be conclusive. The Participant’s employment shall be considered to
have been terminated for Cause if the Company determines, within 30 days after the Participant’s resignation, that termination for Cause was warranted. 

  
 - 2 - 









	4.	Company Right of First Refusal. 

 (a) Notice of Proposed Transfer. If the
Participant proposes to sell, assign, transfer, pledge, hypothecate or otherwise dispose of, by operation of law or otherwise (collectively, “transfer”) any Shares acquired upon exercise of this option, then the Participant shall first
give written notice of the proposed transfer (the “Transfer Notice”) to the Company. The Transfer Notice shall name the proposed transferee and state the number of such Shares the Participant proposes to transfer (the
“Offered Shares”), the price per share and all other material terms and conditions of the transfer. 
 (b) Company Right
to Purchase. For 30 days following its receipt of such Transfer Notice, the Company shall have the option to purchase all or part of the Offered Shares at the price and upon the terms set forth in the Transfer Notice. In the event the Company
elects to purchase all or part of the Offered Shares, it shall give written notice of such election to the Participant within such 30-day period. Within 10 days after his or her receipt of such notice, the
Participant shall tender to the Company at its principal offices the certificate or certificates representing the Offered Shares to be purchased by the Company, duly endorsed in blank by the Participant or with duly endorsed stock powers attached
thereto, all in a form suitable for transfer of the Offered Shares to the Company. Promptly following receipt of such certificate or certificates, the Company shall deliver or mail to the Participant a check in payment of the purchase price for such
Offered Shares; provided that if the terms of payment set forth in the Transfer Notice were other than cash against delivery, the Company may pay for the Offered Shares on the same terms and conditions as were set forth in the Transfer
Notice; and provided further that any delay in making such payment shall not invalidate the Company’s exercise of its option to purchase the Offered Shares. 

(c) Shares Not Purchased By Company. If the Company does not elect to acquire all of the Offered Shares, the Participant may, within the
30-day period following the expiration of the option granted to the Company under subsection (b) above, transfer the Offered Shares which the Company has not elected to acquire to the proposed transferee,
provided that such transfer shall not be on terms and conditions more favorable to the transferee than those contained in the Transfer Notice. Notwithstanding any of the above, all Offered Shares transferred pursuant to this
Section 4 shall remain subject to the right of first refusal set forth in this Section 4 and such transferee shall, as a condition to such transfer, deliver to the Company a written instrument confirming that such transferee shall be bound
by all of the terms and conditions of this Section 4. 
 (d) Consequences of
Non-Delivery. After the time at which the Offered Shares are required to be delivered to the Company for transfer to the Company pursuant to subsection (b) above, the Company shall not pay any
dividend to the Participant on account of such Offered Shares or permit the Participant to exercise any of the privileges or rights of a stockholder with respect to such Offered Shares, but shall, insofar as permitted by law, treat the Company as
the owner of such Offered Shares. 

  
 - 3 - 








 (e) Exempt Transactions. The following transactions shall be exempt from the provisions of
this Section 4: 
 (1) any transfer of Shares to or for the benefit of any spouse, child or grandchild of the Participant, or to a trust
for their benefit; 
 (2) any transfer pursuant to an effective registration statement filed by the Company under the Securities Act of 1933,
as amended (the “Securities Act”); and 
 (3) the sale of all or substantially all of the outstanding shares of capital
stock of the Company (including pursuant to a merger or consolidation); 
 provided, however, that in the case of a transfer pursuant to clause
(1) above, such Shares shall remain subject to the right of first refusal set forth in this Section 4. 
 (f) Assignment of
Company Right. The Company may assign its rights to purchase Offered Shares in any particular transaction under this Section 4 to one or more persons or entities. 

(g) Termination. The provisions of this Section 4 shall terminate upon the earlier of the following events: 

(1) the closing of the sale of shares of Common Stock in an underwritten public offering pursuant to an effective registration statement filed
by the Company under the Securities Act; or 
 (2) 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 merger or consolidation in which all or substantially all of the individuals and entities who were beneficial owners of the Company’s voting securities
immediately prior to such transaction beneficially own, directly or indirectly, more than 75% (determined on an as-converted basis) of the outstanding securities entitled to vote generally in the election of
directors of the resulting, surviving or acquiring corporation in such transaction). 
 (h) No Obligation to Recognize Invalid
Transfer. The Company shall not be required (1) to transfer on its books any of the Shares which shall have been sold or transferred in violation of any of the provisions set forth in this Section 4, or (2) to treat as owner of
such Shares or to pay dividends to any transferee to whom any such Shares shall have been so sold or transferred. 
 (i) Legends. The
certificate representing Shares shall bear a legend substantially in the following form (in addition to, or in combination with, any legend required by applicable federal and state securities laws and agreements relating to the transfer of the
Company securities): 
 “The shares represented by this certificate are subject to a right of first refusal in favor of the Company, as
provided in a certain stock option agreement with the Company.” 

  
 - 4 - 









	5.	Agreement in Connection with Initial Public Offering. 

 The Participant agrees, in connection with the
initial underwritten public offering of the Common Stock pursuant to a registration statement under the Securities Act, (i) not to (a) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to
purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any other securities of the Company or (b) enter into
any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of shares of Common Stock or other securities of the Company, whether any transaction described in clause (a) or (b) is to be settled
by delivery of securities, in cash or otherwise, during the period beginning on the date of the filing of such registration statement with the Securities and Exchange Commission and ending 180 days after the date of the final prospectus relating to
the offering (plus up to an additional 34 days to the extent requested by the managing underwriters for such offering in order to address FINRA Rule 2241 or NYSE Rule 472(f)(4) or any similar successor provision), and (ii) to execute any
agreement reflecting clause (i) above as may be requested by the Company or the managing underwriters at the time of such offering. The Company may impose stop-transfer instructions with respect to the shares of Common Stock or other securities
subject to the foregoing restriction until the end of the “lock-up” period. 
  

	6.	Tax Matters. 

 (a) Withholding. No Shares will be issued pursuant to the exercise
of this option unless and until the Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes required by law to be withheld in respect of this option. 

(b) Disqualifying Disposition. If the Participant disposes of Shares acquired upon exercise of this option within two years from the
Grant Date or one year after such Shares were acquired pursuant to exercise of this option, the Participant shall notify the Company in writing of such disposition. 
  

	7.	Transfer Restrictions. 

 (a) This option may not be sold, assigned, transferred, pledged
or otherwise encumbered by the Participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution, and, during the lifetime of the Participant, this option shall be exercisable only by the Participant.  
 (b) The Participant agrees that he or she will not transfer any Shares issued pursuant
to the exercise of this option unless the transferee, as a condition to such transfer, delivers to the Company a written instrument confirming that such transferee shall be bound by all of the terms and conditions of Section 4 and
Section 5; provided that such a written confirmation shall not be required with respect to (1) Section 4 after such provision has terminated in accordance with Section 4(g) or (2) Section 5 after the completion of the lock-up period in connection with the Company’s initial underwritten public offering. 

  
 - 5 - 









	8.	Provisions of the Plan. 

 This option is subject to the provisions of the Plan (including
the provisions relating to amendments to the Plan), a copy of which is furnished to the Participant with this option. Participant hereby agrees to execute such further instruments and to take such further action as the Company requests to carry out
the purposes and intent of the Plan, including, without limitation, restrictions on the transferability of shares of Common Stock, the right of the Company to repurchase shares of Common Stock, the right of the Company to require that shares of
Common Stock be transferred in the event of certain transactions, tag-along rights, bring-along rights, redemption and co-sale rights and voting requirements. 

[Remainder of Page Intentionally Left Blank] 

  
 - 6 - 








 IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day and year first
above written. The Participant hereby accepts the foregoing option and agrees to the terms and conditions thereof. The Participant hereby acknowledges receipt of a copy of the Company’s 2015 Stock Incentive Plan. 

 

					
	COMPANY:
	
	Evelo Biosciences, Inc.
		
	By:	 	  

		 	Name:	 	  

		 	Title:	 	  

	
	PARTICIPANT:
		
	By:	 	  

		 	[Name]	 	
		
	Address:	 	[                                      
                                         
 ]
		 		 	[                                      
                                         
 ]
	
	SPOUSAL
CONSENT:1
		
	By:	 	  

		 	Name:	 	
		
	Address:	 	[                                      
                                         
 ]
		 		 	[                                      
                                         
 ]


  

	1 	If the Participant resides in a community property state, it is desirable to have the Participant’s spouse also accept the option. The following are community property states: Arizona, California, Idaho, Louisiana,
Nevada, New Mexico, Texas, and Washington. Although Wisconsin is not formally a community property state, it has laws governing the division of marital property similar to community property states and it may be desirable to have a Wisconsin
Participant’s spouse accept the option. 

 SIGNATURE PAGE TO INCENTIVE STOCK OPTION AGREEMENT 







 EXHIBIT A 

NOTICE OF STOCK OPTION EXERCISE 

[DATE]1 

Evelo Biosciences, Inc. 
 One Memorial Drive, 7th Floor 
 Cambridge, MA 02142 

Attention: Treasurer 
 Dear Sir or Madam: 

I am the holder of an Incentive Stock Option granted to me under the Evelo Biosciences, Inc. (the “Company”) 2015 Stock
Incentive Plan on                     2 for the purchase of
                    3 shares of Common Stock of the Company at a purchase price of
$                    4 per share. 

I hereby exercise my option to purchase
                    5 shares of Common Stock (the “Shares”), for which I have
enclosed                     6 in the amount of
                    7. Please register my stock certificate as follows: 

 

							
	 Name(s):
	 		  	 8
	  	
				
		 		  	 	  	
				
	Address:	 		  	 	  	
				
		 		  	 	  	


 I represent, warrant and covenant as follows: 

 

	1 	Enter date of exercise. 


	2 	Enter the date of grant. 


	3 	Enter the total number of shares of Common Stock for which the option was granted. 


	4 	Enter the option exercise price per share of Common Stock. 


	5 	Enter the number of shares of Common Stock to be purchased upon exercise of all or part of the option. 


	6 	Enter “cash”, “personal check” or if permitted by the option or Plan, “stock certificates No. XXXX and XXXX”. 


	7 	Enter the dollar amount (price per share of Common Stock times the number of shares of Common Stock to be purchased), or the number of shares tendered. Fair market value of shares tendered, together with cash or check,
must cover the purchase price of the shares issued upon exercise. 


	8 	Enter name(s) to appear on stock certificate in one of the following formats: (a) your name only (i.e., John Doe); (b) your name and other name (i.e., John Doe and Jane Doe, Joint Tenants with Right to Survivorship); or
for Nonstatutory Stock Options only, (c) a child’s name, with you as custodian (i.e. Jane Doe, Custodian for Tommy Doe). Note: There may be income and/or gift tax consequences for registering shares in a child’s name. 








 1. I am purchasing the Shares for my own account for investment only, and not with a view to, or for sale in
connection with, any distribution of the Shares in violation of the Securities Act of 1933 (the “Securities Act”), or any rule or regulation under the Securities Act. 

2. I have had such opportunity as I have deemed adequate to obtain from representatives of the Company such information as is necessary to permit me to
evaluate the merits and risks of my investment in the Company. 
 3. I have sufficient experience in business, financial and investment matters to be able to
evaluate the risks involved in the purchase of the Shares and to make an informed investment decision with respect to such purchase. 
 4. I can afford a
complete loss of the value of the Shares and am able to bear the economic risk of holding such Shares for an indefinite period. 
 5. I understand that
(i) the Shares have not been registered under the Securities Act and are “restricted securities” within the meaning of Rule 144 under the Securities Act, (ii) the Shares cannot be sold, transferred or otherwise disposed of unless
they are subsequently registered under the Securities Act or an exemption from registration is then available; (iii) in any event, the exemption from registration under Rule 144 will not be available for at least one year and even then will not
be available unless a public market then exists for the Common Stock, adequate information concerning the Company is then available to the public, and other terms and conditions of Rule 144 are complied with; and (iv) there is now no
registration statement on file with the Securities and Exchange Commission with respect to any stock of the Company and the Company has no obligation or current intention to register the Shares under the Securities Act. 

6. I agree to take such further action and to execute such further instruments as the Company requests relating to the Shares, including, without limitation,
to implement restrictions on the transferability of Shares, the right of the Company to repurchase Shares, the right of the Company to require that Shares be transferred in the event of certain transactions,
tag-along rights, bring-along rights, redemption and co-sale rights and voting requirements. 
  

	
	 Very truly yours,

	
	  

[Name]



  
 - 9 - 








 EVELO BIOSCIENCES, INC. 

2015 STOCK INCENTIVE PLAN 

SUB-PLAN FOR UK EMPLOYEES 

 

	1.	Purpose for Construction 

  

	 	(a)	Pursuant to the powers granted by the Board in Section 11(e) of the Evelo Biosciences, Inc. 2015 Stock Incentive Plan (as amended or restated from time to time, the “Plan”), the Board has adopted
this UK Sub-Plan (the “Sub-Plan”). The purpose of the Sub-Plan is to promote the success and enhance the value
of Evelo Biosciences, Inc. (the “Company”), by linking the individual interests of Employees, to those of Company stockholders and by providing such individuals with an incentive for outstanding performance to generate superior
returns to Company stockholders. The Sub-Plan is further intended to provide flexibility to the Company in its ability to motivate, attract, and retain the services of Employees upon whose judgment, interest,
and special effort the successful conduct of the Company’s operation is largely dependent. Only Employees (and not officers, directors and consultants) may receive Awards under the Sub-Plan.


  

	 	(b)	Capitalized terms used in the Sub-Plan which are not defined herein shall have the meaning given in the Plan, and where the context requires any references to the “Plan”
in those definitions shall be a reference to the Sub-Plan. The singular pronoun shall include the plural where the context so indicates. Wherever the following terms are: (i) used in the Sub-Plan; or (ii) used in the Plan but apply to Awards made under the Sub-Plan, they shall have the meanings specified below, unless the context clearly indicates
otherwise: 

  

	 	(i)	“Award” means, individually, or collectively, a grant under the Sub-Plan of an Option, a Stock Appreciation Right, a Restricted Stock award, a Restricted Stock Unit
award or an Other Stock Based Award; and 

  

	 	(ii)	“Employee” shall mean any person who is an employee of the Company or its Subsidiaries as determined by the Board. 

  

	2.	Eligibility 

  

	 	(a)	The provisions of Section 2 of the Plan shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan
except that only Employees (and not officers, directors or consultants) shall be eligible to receive Awards under the Sub-Plan. 


 

	 	(b)	The Sub-Plan forms the rules of the employee share scheme applicable to Awards made under the Sub-Plan to Employees. 









	 	(c)	The following language set out below is in addition to the terms of Section 2: 


“Neither the Sub-Plan nor any Award made under the
Sub-Plan shall give the Participant any rights to compensation or damages including for any loss or potential loss that the Participant may suffer by reason of being unable to exercise any Option or
forfeiting any Award or shares of Common Stock as a result of the termination of the Sub-Plan, the lapsing or termination of an Award or the Participant’s termination of employment including where any
termination of employment is subsequently held to be wrongful or unfair.” 
  

	3.	Administration and Delegation 

 The provisions of Section 3 of the Plan shall apply
to this Sub-Plan as if references to the Plan are references to the Sub-Plan. 
  

	4.	Stock Available for Awards 

  

	 	(a)	Subject to the terms of Section 4(b) of this Sub-Plan, the provisions of Section 4 of the Plan shall apply to this Sub-Plan as if
references to the Plan are references to the Sub-Plan. 

  

	 	(b)	The aggregate number of Shares which may be issued or transferred pursuant to Awards under the Sub-Plan, when taken together with the number of Shares which may be issued or
transferred pursuant to Awards under the Plan or any other sub-plan shall not exceed the limits specified by Section 4 of the Plan, as amended from time to time. 


 

	5.	Stock Options 

 The provisions of Section 5 of the Plan shall apply to this Sub-Plan as if references to the Plan were references to the Sub-Plan. 
  

	6.	Stock Appreciation Rights 

 The provisions of Section 6 (Stock Appreciation Rights)
of the Plan shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan. 

 

	7.	Restricted Stock; Restricted Stock Units 

 The provisions of Section 7 of the Plan
shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan. On request by the Company, Employees tax resident in the United Kingdom will be
required to make an election under Section 431 of Chapter 2 Income Tax (Earnings and Pensions) Act 2003 (“ITEPA”) for full disapplication of ITEPA. Employees tax resident in other jurisdictions may be required to make
equivalent elections appropriate to their jurisdictions. 








	8.	Other Stock-Based Awards 

 The provisions of Section 8 of the Plan shall apply to
this Sub-Plan as if references to the Plan are references to the Sub-Plan. 
  

	9.	Adjustment for Changes in Common Stock and Certain Other Events 

 The provisions of
Section 9 of the Plan shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan. 

 

	10.	General Provisions Applicable to Awards 

  

	 	(a)	Except as set out below, the provisions of Section 10 of the Plan shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan. 

  

	 	(b)	Section 10(e) of the Plan (Withholding) shall be amended so that the term “all applicable federal, state, and local or other income and employment tax withholding obligations” when used in
Section 10(e) shall include: 

 “income tax, employee’s National Insurance contributions and (at
the discretion of the Company) employer’s National Insurance contributions or other similar taxes arising in any jurisdiction (any, a “Tax Liability”)”  

 

	 	(c)	At the end of Section 10(e), the following shall be added: 

 “The Participant will
indemnify and keep indemnified the Company and his/her employing company, if different, from and against any liability for or obligation to pay any Tax Liability.”  

 

	11.	Miscellaneous 

 Except as set out below, the provisions of Section 11(d) of the Plan
shall apply to this Sub-Plan as if references to the Plan are references to the Sub-Plan. 
  

	12.	Additional Provisions 

 In the event of a conflict between the terms of the Sub-Plan and the Plan with respect to Awards granted to Employees under the Sub-Plan, the terms of the Sub-Plan will control. 







 EVELO BIOSCIENCES, INC. 

NONSTATUTORY OPTION AGREEMENT 

GRANTED UNDER 2015 STOCK INCENTIVE PLAN UK
SUB-PLAN FOR UNITED KINGDOM 
 PARTICIPANTS

  

	1.	Grant of Option. 

 This UK Option Agreement, which incorporates the form in Exhibit A
attached hereto (collectively, the “UK Option Agreement”) evidences the grant by Evelo Biosciences, Inc., a Delaware corporation (the “Company”), on
[                 , 20        ] (the “Grant Date”) to
[                        ], an employee of the Company (the “Participant”), of an option to purchase, in whole
or in part, on the terms provided herein and in the Company’s 2015 Stock Incentive Plan UK Sub-Plan (incorporating terms from the Evelo Biosciences, Inc. 2015 Stock Incentive Plan) (respectively, the
“UK Sub-Plan” and the “Plan”), a total of [                    ] shares
(the “Shares”) of common stock, $0.001 par value per share, of the Company (“Common Stock”) at $[                ] per Share. Unless
earlier terminated, this option shall expire at 5:00 p.m., Eastern time, on [                     ,
20        ] [date is ten years minus one day from grant date] (the “Final Exercise Date”). 

It is intended that the option evidenced by this UK Option Agreement shall not be an incentive stock option as defined in Section 422 of
the Internal Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the “Code”). Except as otherwise indicated by the context, the term “Participant”, as used in this option, shall be deemed
to include any person who acquires the right to exercise this option validly under its terms. This UK Option Agreement forms the rules of the employee share scheme applicable to the United Kingdom based employees of the Company. 

 

	2.	Vesting Schedule. 

 This option will become exercisable (“vest”) as to
25% of the original number of Shares on the first anniversary of the Vesting Commencement Date (as defined below) and as to an additional 6.25% of the original number of Shares at the end of each successive quarter following the first anniversary of
the Vesting Commencement Date until the fourth anniversary of the Vesting Commencement Date. On the fourth anniversary of the Vesting Commencement Date, this option will be exercisable as to all Shares. For purposes of this UK Option Agreement,
“Vesting Commencement Date” shall mean [                    ]. 

The right of exercise shall be cumulative so that to the extent the option is not exercised in any period to the maximum extent permissible it
shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or the termination of this option under Section 3 hereof or the UK Sub-Plan. 
  

	3.	Exercise of Option. 

 (a) Form of Exercise. Each election to exercise this option
shall be accompanied by a completed Notice of Option Exercise in the form attached hereto as Exhibit A, signed by the 







 Participant, and received by the Company at its principal office, accompanied by this UK Option Agreement, and
payment in full in the manner provided in the UK Sub-Plan. The Participant may purchase less than the number of Shares covered hereby, provided that no partial exercise of this option may be for any fractional
share or for fewer than ten whole shares. 
 (b) Continuous Employment with the Company Required. Except as otherwise provided in this
Section 3, this option may not be exercised unless the Participant, at the time he or she exercises this option, is, and has been at all times since the Grant Date, an employee of the Company or any other entity the employees of which are
eligible to receive option grants under the UK Sub-Plan (an “Eligible Participant”). 

(c) Termination of Employment with the Company. If the Participant ceases to be an Eligible Participant for any reason, then, except as
provided in paragraphs (d) and (e) below, the right to exercise this option shall terminate three months after such cessation (but in no event after the Final Exercise Date), provided that this option shall be exercisable only to
the extent that the Participant was entitled to exercise this option on the date of such cessation. Notwithstanding the foregoing, if the Participant, prior to the Final Exercise Date, violates the
non-competition or confidentiality provisions of any employment contract, confidentiality and nondisclosure agreement or other agreement between the Participant and the Company, the right to exercise this
option shall terminate immediately upon such violation. 
 (d) Exercise Period Upon Death or Disability. If the Participant dies or
becomes disabled (within the meaning of Section 22(e)(3) of the Code) prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for “cause” as specified in
paragraph (e) below, this option shall be exercisable, within the period of one year following the date of death or disability of the Participant, by the Participant (or in the case of death by an authorized transferee), provided
that this option shall be exercisable only to the extent that this option was exercisable by the Participant on the date of his or her death or disability, and further provided that this option shall not be exercisable after the Final
Exercise Date. 
 (e) Termination for Cause. If, prior to the Final Exercise Date, the Participant’s employment with the Company
is terminated by the Company for Cause (as defined below), the right to exercise this option shall terminate immediately upon the effective date of such termination of employment. If, prior to the Final Exercise Date, the Participant is given notice
by the Company of the termination of his or her employment by the Company for Cause, and the effective date of such employment termination is subsequent to the date of the delivery of such notice, the right to exercise this option shall be suspended
from the time of the delivery of such notice until the earlier of (i) such time as it is determined or otherwise agreed that the Participant’s employment shall not be terminated for Cause as provided in such notice or (ii) the
effective date of such termination of employment (in which case the right to exercise this option shall, pursuant to the preceding sentence, terminate immediately upon the effective date of such termination of employment). If the Participant is
party to an employment, consulting or severance agreement with the Company that contains a definition of “cause” for termination of employment, “Cause” shall have the meaning ascribed to such term in such agreement. Otherwise,
“Cause” shall mean willful misconduct by the Participant or willful failure by the Participant to perform his or her responsibilities to the Company (including, without limitation, breach by the Participant of any 

  
 -2- 








 provision of any employment, nondisclosure, non-competition or other
similar agreement between the Participant and the Company), as determined by the Company, which determination shall be conclusive. The Participant’s employment shall be considered to have been terminated for “Cause” if the Company
determines, within 30 days after the Participant’s resignation, that termination for Cause was warranted. 
  

	4.	Company Right of First Refusal. 

 (a) Notice of Proposed Transfer. If the
Participant proposes to sell, assign, transfer, pledge, hypothecate or otherwise dispose of, by operation of law or otherwise (collectively, “transfer”) any Shares acquired upon exercise of this option, then the Participant shall first
give written notice of the proposed transfer (the “Transfer Notice”) to the Company. The Transfer Notice shall name the proposed transferee and state the number of such Shares the Participant proposes to transfer (the
“Offered Shares”), the price per share and all other material terms and conditions of the transfer. 
 (b) Company Right
to Purchase. For 30 days following its receipt of such Transfer Notice, the Company shall have the option to purchase all or part of the Offered Shares at the price and upon the terms set forth in the Transfer Notice. In the event the Company
elects to purchase all or part of the Offered Shares, it shall give written notice of such election to the Participant within such 30-day period. Within 10 days after his or her receipt of such notice, the
Participant shall tender to the Company at its principal offices the certificate or certificates representing the Offered Shares to be purchased by the Company, duly endorsed in blank by the Participant or with duly endorsed stock powers attached
thereto, all in a form suitable for transfer of the Offered Shares to the Company. Promptly following receipt of such certificate or certificates, the Company shall deliver or mail to the Participant a check in payment of the purchase price for such
Offered Shares; provided that if the terms of payment set forth in the Transfer Notice were other than cash against delivery, the Company may pay for the Offered Shares on the same terms and conditions as were set forth in the Transfer
Notice; and provided further that any delay in making such payment shall not invalidate the Company’s exercise of its option to purchase the Offered Shares. 

(c) Shares Not Purchased By Company. If the Company does not elect to acquire all of the Offered Shares, the Participant may, within the
30-day period following the expiration of the option granted to the Company under subsection (b) above, transfer the Offered Shares which the Company has not elected to acquire to the proposed transferee,
provided that such transfer shall not be on terms and conditions more favorable to the transferee than those contained in the Transfer Notice. Notwithstanding any of the above, all Offered Shares transferred pursuant to this Section 4
shall remain subject to the right of first refusal set forth in this Section 4 and such transferee shall, as a condition to such transfer, deliver to the Company a written instrument confirming that such transferee shall be bound by all of the
terms and conditions of this Section 4. 
 (d) Consequences of Non-Delivery. After the
time at which the Offered Shares are required to be delivered to the Company for transfer to the Company pursuant to subsection (b) above, the Company shall not pay any dividend to the Participant on account of such Offered Shares or permit the
Participant to exercise any of the privileges or rights of a stockholder with respect to such Offered Shares, but shall, insofar as permitted by law, treat the Company as the owner of such Offered Shares. 

  
 -3- 








 (e) Exempt Transactions. The following transactions shall be exempt from the provisions of
this Section 4: 
 (1) any transfer of Shares to or for the benefit of any spouse, child or grandchild of the Participant, or to a trust
for their benefit; 
 (2) any transfer pursuant to an effective registration statement filed by the Company under the Securities Act of 1933,
as amended (the “Securities Act”); and 
 (3) the sale of all or substantially all of the outstanding shares of capital
stock of the Company (including pursuant to a merger or consolidation); 
 provided, however, that in the case of a transfer pursuant to
clause (1) above, such Shares shall remain subject to the right of first refusal set forth in this Section 4. 
 (f) Assignment
of Company Right. The Company may assign its rights to purchase Offered Shares in any particular transaction under this Section 4 to one or more persons or entities. 

(g) Termination. The provisions of this Section 4 shall terminate upon the earlier of the following events: 

(1) the closing of the sale of shares of Common Stock in an underwritten public offering pursuant to an effective registration statement filed
by the Company under the Securities Act; or 
 (2) 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 merger or consolidation in which all or substantially all of the individuals and entities who were beneficial owners of the Company’s voting securities
immediately prior to such transaction beneficially own, directly or indirectly, more than 75% (determined on an as-converted basis) of the outstanding securities entitled to vote generally in the election of
directors of the resulting, surviving or acquiring corporation in such transaction). 
 (h) No Obligation to Recognize Invalid
Transfer. The Company shall not be required (1) to transfer on its books any of the Shares which shall have been sold or transferred in violation of any of the provisions set forth in this Section 4, or (2) to treat as owner of such
Shares or to pay dividends to any transferee to whom any such Shares shall have been so sold or transferred. 
 (i) Legends. The
certificate representing Shares shall bear a legend substantially in the following form (in addition to, or in combination with, any legend required by applicable federal and state securities laws and agreements relating to the transfer of the
Company securities): 
 “The shares represented by this certificate are subject to a right of first refusal in favor of the Company, as
provided in a certain option agreement with the Company.” 

  
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	5.	Agreement in Connection with Initial Public Offering. 

 The Participant agrees, in
connection with the initial underwritten public offering of the Common Stock pursuant to a registration statement under the Securities Act, (i) not to (a) offer, pledge, announce the intention to sell, sell, contract to sell, sell any
option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any other securities of the Company
or (b) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of shares of Common Stock or other securities of the Company, whether any transaction described in clause
(a) or (b) is to be settled by delivery of securities, in cash or otherwise, during the period beginning on the date of the filing of such registration statement with the Securities and Exchange Commission and ending 180 days after the date of
the final prospectus relating to the offering (plus up to an additional 34 days to the extent requested by the managing underwriters for such offering in order to address NASD Rule 2711(f)(4) or NYSE Rule 472(f)(4) or any similar successor
provision), and (ii) to execute any agreement reflecting clause (i) above as may be requested by the Company or the managing underwriters at the time of such offering. The Company may impose stop-transfer instructions with respect to the
shares of Common Stock or other securities subject to the foregoing restriction until the end of the “lock-up” period. 
  

	6.	UK Tax Obligations. 

 (a) No Shares will be issued pursuant to the exercise of this
option unless and until the Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes (including employee’s and, at the Company’s discretion,
employer’s National Insurance contributions or other social security contributions (any a “Tax Liability”)), whether arising in the United Kingdom or any other jurisdiction in connection with (1) grant, vesting or
exercise of the option or any benefit derived by the Participant from the option; (2) the transfer or issue of Shares to Participant on satisfaction of the option; (3) the lapse or removal of any or all of the restrictions that apply to
the Shares; or (4) the disposal of any Shares (each of those events referred to as a “Taxable Event”). The Company shall not be required to issue, allot or transfer shares until the Participant has made such arrangements as the
Company may require for the satisfaction of any Tax Liability that may arise in connection with a Taxable Event. 
 (b) The Participant
agrees to indemnify and keep indemnified the Company and his/her employing company (“Employer”), if different, from and against any liability for or obligation to pay any Tax Liability that is attributable to a Taxable Event. 

(c) The Participant undertakes that, upon request by the Company, he/she will join with his/her Employer in electing, pursuant to
Section 431 of the Income Tax (Earnings and Pensions) Act 2003 (“ITEPA”) that, for relevant tax purposes, the market value of this option on any occasion will be calculated as if this option was not restricted and Sections 425 to 430
(inclusive) of ITEPA are not to apply to such shares. 

  
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	7.	Transfer Restrictions.  

 (a) This option may not be sold, assigned, transferred, pledged
or otherwise encumbered by the Participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution, and, during the lifetime of the Participant, this option shall be exercisable only by the Participant.

 (b) The Participant agrees that he or she will not transfer any Shares issued pursuant to the exercise of this option unless the
transferee, as a condition to such transfer, delivers to the Company a written instrument confirming that such transferee shall be bound by all of the terms and conditions of Section 4 and Section 5; provided that such a written
confirmation shall not be required with respect to (1) Section 4 after such provision has terminated in accordance with Section 4(g) or (2) Section 5 after the completion of the
lock-up period in connection with the Company’s initial underwritten public offering. 
  

	8.	Provisions of the UK Sub-Plan. 

 This option is
subject to the provisions of the UK Sub-Plan which is incorporated herein by reference, a copy of which is furnished to the Participant with this option, save that in the United Kingdom only employees are
eligible to be granted options. Consultants and advisors are not eligible to be granted options in the United Kingdom. In the event of a conflict between the terms of the UK Option Agreement and the UK
Sub-Plan, the terms of the UK Option Agreement shall control. 
  

	9.	Compliance with Federal Anti-Kickback Statute. 

 The parties acknowledge and agree that
this option represents the fair market value of the services provided by the Participant to the Company, negotiated in an arm’s-length transaction, and does not take into account the volume or value of
any referrals or business otherwise generated by the Participant. The parties acknowledge and agree that this UK Option Agreement is intended to comply in all respects with the federal Anti-Kickback Statute, 42 U.S.C. § 1320a-7b(b), including any applicable statutory and regulatory exceptions or safe harbors. 
  

	10.	Data Protection. 

 By signing this UK Option Agreement, the Participant acknowledges and
agrees that: 
 (a) the Company and any parent, subsidiary or affiliate are permitted to hold and process personal (and sensitive)
information and data about the Optionee as part of their personnel and other business records and may use such information in the course of its business; 

(b) the Company and any parent, subsidiary or affiliate may disclose such information (as described in (a) above) to third parties,
including where they are situated outside the European Economic Area, in the event that such disclosure is in their view required for the proper conduct of their business; and 
  


	 	(c)	this section applies to information held, used or disclosed in any medium. 


  
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	11.	Not a Contract of Employment.  

 Nothing in this UK Option Agreement or in the UK Sub-Plan shall confer upon the Participant any right to continue to serve as an employee of the Company or any of its affiliates. The terms of the Participant’s employment with the Company or its affiliates are
not affected or changed in any way by this option and neither the UK Sub-Plan nor this UK Option Agreement afford the Participant any rights to compensation or damages including for loss or potential loss that
the Participant may suffer in respect of this option as a result of the termination of the UK Sub-Plan or the termination of the Participant’s employment. 

 

	12.	Agreement Severable  

 In the event that any provision in this UK Option Agreement is
held illegal or invalid, the provision will be severable from, and the illegality or invalidity of the provision will not be construed to have any effect on, the remaining provisions of this UK Option Agreement. 

 

	13.	Acknowledgement  

 Participant acknowledges that neither this UK Option Agreement nor the
UK Sub-Plan has been issued, nor has it been approved by an authorised person within the meaning of the Financial Services and Markets Act 2000 of the United Kingdom and is being directed at the Participant
because the offer to which this UK Option Agreement and the UK Sub-Plan relate has been determined as having regard to the Participant’s circumstances as an employee of the Company. This UK Option
Agreement is strictly confidential and is not for distribution to, and may not be acted upon by, any other person other than the person to whom it has been specifically addressed. 

[Remainder of Page Intentionally Left Blank] 

  
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 IN WITNESS WHEREOF, the parties hereto have executed this UK Option Agreement as of the day and
year first above written. The Participant hereby accepts the foregoing option and agrees to the terms and conditions of the UK Sub-Plan and the UK Option Agreement. Participant has reviewed the UK Sub-Plan and the UK Option Agreement in their entirety, has had an opportunity to obtain the advice of counsel prior to executing this UK Option Agreement and fully understands all provisions of the UK Sub-Plan and the UK Option Agreement. Participant hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Administrator upon any questions arising under the UK Sub-Plan or the UK Option Agreement. The Participant hereby acknowledges receipt of a copy of the UK Sub-Plan. 

 

			
	COMPANY:
	
	Evelo Biosciences, Inc.
		
	By:	 	  

		 	Name:
		 	Title:


 
			
	
	PARTICIPANT:


 
			
		
	By:	 	
                     
                        

		 	[Name]
	
	Address: [                                  
      ]
	               [                     
                   ]


 SIGNATURE PAGE TO NONSTATUTORY STOCK OPTION AGREEMENT 







 EXHIBIT A 

NOTICE OF OPTION EXERCISE 

[DATE]1 

Evelo Biosciences, Inc. 
 One Memorial Drive 

Cambridge, MA 02142 
 Attention: Treasurer 

Dear Sir or Madam: 
 I am the holder of an Option
granted to me under the Evelo Biosciences, Inc. (the “Company”) 2015 Stock Incentive Plan UK Sub-Plan on
[                ]2 for the purchase of
[                ]3 shares of Common Stock of the Company at a purchase price of
$[            ]4 per share. 

I hereby exercise my option to purchase [                ]5 shares of Common Stock (the “Shares”), for which I have enclosed [                ]6 in the amount of [                ]7. Please register my stock
certificate as follows: 
  

					
		 	Name(s):	 	                                      
                                  8
		 		 	                                    
                                    
	 	 
		 	Address:	 	                                      
                                  
		 		 	                                      
                                  

  

	1 	Enter date of exercise. 


	2	Enter the date of grant. 


	3	Enter the total number of shares of Common Stock for which the option was granted. 


	4	Enter the option exercise price per share of Common Stock. 


	5	Enter the number of shares of Common Stock to be purchased upon exercise of all or part of the option.



	6	Enter “cash”, “personal check” or if permitted by the option or Plan, “stock
certificates No. XXXX and XXXX”. 


	7 	Enter the dollar amount (price per share of Common Stock times the number of shares of Common Stock to be purchased), or the number of shares tendered. Fair market
value of shares tendered, together with cash or check, must cover the purchase price of the shares issued upon exercise. 


	8 	Enter name(s) to appear on stock certificate in one of the following formats: (a) your name only (i.e., John Doe); (b) your name and other name (i.e., John Doe
and Jane Doe, Joint Tenants with Right to Survivorship); or for Nonstatutory Stock Options only, (c) a child’s name, with you as custodian (i.e. Jane Doe, Custodian for Tommy Doe). Note: There may be income and/or gift tax consequences for
registering shares in a child’s name. 








 I represent, warrant and covenant as follows: 

1. I am purchasing the Shares for my own account for investment only, and not with a view to, or for sale in connection with, any distribution of the Shares in
violation of the Securities Act of 1933 (the “Securities Act”), or any rule or regulation under the Securities Act. 
 2. I have had such
opportunity as I have deemed adequate to obtain from representatives of the Company such information as is necessary to permit me to evaluate the merits and risks of my investment in the Company. 

3. I have sufficient experience in business, financial and investment matters to be able to evaluate the risks involved in the purchase of the Shares and to
make an informed investment decision with respect to such purchase. 
 4. I can afford a complete loss of the value of the Shares and am able to bear the
economic risk of holding such Shares for an indefinite period. 
 5. I understand that (i) the Shares have not been registered under the Securities Act
and are “restricted securities” within the meaning of Rule 144 under the Securities Act, (ii) the Shares cannot be sold, transferred or otherwise disposed of unless they are subsequently registered under the Securities Act or an
exemption from registration is then available; (iii) in any event, the exemption from registration under Rule 144 will not be available for at least one year and even then will not be available unless a public market then exists for the Common
Stock, adequate information concerning the Company is then available to the public, and other terms and conditions of Rule 144 are complied with; and (iv) there is now no registration statement on file with the Securities and Exchange
Commission with respect to any stock of the Company and the Company has no obligation or current intention to register the Shares under the Securities Act. 

6. I agree to take such further action and to execute such further instruments as the Company requests relating to the Shares, including, without limitation,
to implement restrictions on the transferability of Shares, the right of the Company to repurchase Shares, the right of the Company to require that Shares be transferred in the event of certain transactions,
tag-along rights, bring-along rights, redemption and co-sale rights and voting requirements. 
  

	
	Very truly yours,
	
	  
 [Name]



  
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