Document:

EX-10.8

 Exhibit 10.8 

EXECUTION VERSION 

KALEIDO BIOSCIENCES, INC. 

EMPLOYMENT AGREEMENT 

This Employment Agreement (“Agreement”) is made as of January 24, 2019, between Kaleido Biosciences, Inc., a Delaware
corporation (the “Company”), and Michael Bonney (the “Employee”) and is effective as of the closing of the Company’s first underwritten public offering of its equity securities pursuant to an effective
registration statement under the Securities Act of 1933, as amended (the “Effective Date”). 
 WHEREAS, the Company and the
Employee are parties to an offer letter, dated May 17, 2017, as amended by letter dated August 16, 2018 (the “Prior Agreement”); and 

WHEREAS, the parties intend to replace the Prior Agreement with this Agreement, effective as of the Effective Date. 

NOW, THEREFORE, in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties agree as follows: 
 1.    Employment. 

(a)    Term. The term of this Agreement shall commence on the Effective Date and continue until terminated in
accordance with the provisions hereof (the “Term”). The Employee’s employment with the Company will continue to be “at will,” meaning that the Employee’s employment may be terminated by the Company or the
Employee at any time and for any reason subject to the terms of this Agreement. 
 (b)    Position and Duties.
During the Term, the Employee shall serve as the Executive Chair of the Company, and shall have such duties and authorities as may from time to time be prescribed by the Company’s Board of Directors (the “Board”). The Employee shall
devote 60% of his full working time and efforts to the business and affairs of the Company. Notwithstanding the foregoing, the Employee may serve on other boards of directors, with the advance written approval of the Board, or engage in religious,
charitable or other community activities as long as such services and activities do not interfere with the Executive’s performance of his duties to the Company as provided in this Agreement. 

2.    Compensation and Related Matters. 

(a)    Base Salary. The Company shall continue the Employee’s base salary at its current rate, subject to
annual review by the Company’s Board of Directors (“Board”). The base salary in effect at any given time is referred to herein as “Base Salary.” The Base Salary shall be payable in a manner that is consistent with the
Company’s usual payroll practices. 
 (b)    Equity. The equity awards held by the Executive shall be
governed by the terms and conditions of the Company’s applicable equity incentive plan(s) and the applicable award agreement(s) governing the terms of such equity awards held by the Executive (collectively, the “Equity Documents”).

 (c)    Expenses. The Employee shall be entitled to receive prompt
reimbursement for all reasonable expenses incurred by him during the Term in performing services hereunder, in accordance with the policies and procedures then in effect and established by the Company. 

(d)    Other Benefits. During the Term, the Employee shall be eligible to participate in or receive benefits under
the Company’s employee benefit plans in effect from time to time, subject to the terms of such plans provided, however, the Employee shall not be entitled to paid vacation. 

3.    Termination. During the Term, the Employee’s employment hereunder may be terminated without any breach
of this Agreement under the following circumstances: 
 (a)    Death. The Employee’s employment hereunder
shall terminate upon his death. 
 (b)    Disability. The Company may terminate the Employee’s employment if
he is disabled and unable to perform the essential functions of the Employee’s then existing position or positions under this Agreement with or without reasonable accommodation for a period of 180 days (which need not be consecutive) in any 12-month period. If any question shall arise as to whether during any period the Employee is disabled so as to be unable to perform the essential functions of the Employee’s then existing position or positions
with or without reasonable accommodation, the Employee may, and at the request of the Company shall, submit to the Company a certification in reasonable detail by a physician selected by the Company to whom the Employee or the Employee’s
guardian has no reasonable objection as to whether the Employee is so disabled or how long such disability is expected to continue, and such certification shall for the purposes of this Agreement be conclusive of the issue. The Employee shall
cooperate with any reasonable request of the physician in connection with such certification. If such question shall arise and the Employee shall fail to submit such certification, the Company’s determination of such issue shall be binding on
the Employee. Nothing in this Section 3(b) shall be construed to waive the Employee’s rights, if any, under existing law including, without limitation, the Family and Medical Leave Act of 1993, 29 U.S.C. §2601 et seq. and the
Americans with Disabilities Act, 42 U.S.C. §12101 et seq. 
 (c)    Termination by Company for Cause.
The Company may terminate the Employee’s employment hereunder for Cause. For purposes of this Agreement, “Cause” shall mean: (i) conduct by the Employee constituting a material act of misconduct in connection with the performance
of his duties, including, without limitation, misappropriation of funds or property of the Company or any of its subsidiaries or affiliates other than the occasional, customary and de minimis use of Company property for personal purposes;
(ii) the commission by the Employee of any felony or a misdemeanor involving moral turpitude, deceit, dishonesty or fraud, or any conduct by the Employee that would reasonably be expected to result in material injury or reputational harm to the
Company or any of its subsidiaries or affiliates if he were retained in his position; (iii) continued non-performance by the Employee of his duties hereunder

  
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(other than by reason of the Employee’s physical or mental illness, incapacity or disability) which has continued for more than 30 days following written notice of such non-performance from the Board; (iv) a breach by the Employee of any of the provisions contained in Section 7 of this Agreement; (v) a material violation by the Employee of the Company’s written
employment policies; or (vi) failure to cooperate with a bona fide internal investigation or an investigation by regulatory or law enforcement authorities, after being instructed by the Company to cooperate, or the willful destruction or
failure to preserve documents or other materials known to be relevant to such investigation or the inducement of others to fail to cooperate or to produce documents or other materials in connection with such investigation. 

(d)    Termination Without Cause. The Company may terminate the Employee’s employment hereunder at any time
without Cause. Any termination by the Company of the Employee’s employment under this Agreement which does not constitute a termination for Cause under Section 3(b) and does not result from the death of the Employee under Section 3(a)
or the disability of the Employee under Section 3(b) shall be deemed a termination without Cause. 

(e)    Termination by the Employee. The Employee may terminate his employment hereunder at any time for any reason,
including but not limited to Good Reason. For purposes of this Agreement, “Good Reason” shall mean that the Employee has complied with the “Good Reason Process” (hereinafter defined) following the occurrence of any of the
following events: (i) a material diminution in the Employee’s responsibilities, authority or duties, provided that the hiring by the Company of any Company officers with customary responsibilities, authority or duties (including any CBO,
CFO or CMO), will not constitute any such material diminution; (ii) a material diminution in the Employee’s Base Salary except for across-the-board salary
reductions based on the Company’s financial performance similarly affecting all or substantially all senior management employees of the Company; (iii) a material change in the geographic location at which the Employee provides services to
the Company, except for required travel for the Company’s business; or (iv) the material breach of this Agreement by the Company. “Good Reason Process” shall mean that (i) the Employee reasonably determines in good faith
that a “Good Reason” condition has occurred; (ii) the Employee notifies the Company in writing of the first occurrence of the Good Reason condition within 60 days of the first occurrence of such condition; (iii) the Employee
cooperates in good faith with the Company’s efforts, for a period not less than 30 days following such notice (the “Cure Period”), to remedy the condition; (iv) notwithstanding such efforts, the Good Reason condition continues to
exist; and (v) the Employee terminates his employment within 60 days after the end of the Cure Period. If the Company cures the Good Reason condition during the Cure Period, Good Reason shall be deemed not to have occurred. 

(f)    Notice of Termination. Except for termination as specified in Section 3(a), any termination of the
Employee’s employment by the Company or any such termination by the Employee shall be communicated by written Notice of Termination to the other party hereto. For purposes of this Agreement, a “Notice of Termination” shall mean a
notice which shall indicate the specific termination provision in this Agreement relied upon. 
 (g)    Date of
Termination. “Date of Termination” shall mean: (i) if the Employee’s employment is terminated by his death, the date of his death; (ii) if the Employee’s 

  
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employment is terminated by the Company on account of the Employee’s disability under Section 3(b) or by the Company for Cause under Section 3(c), the date on which a Notice of
Termination is given; (iii) if the Employee’s employment is terminated by the Employee under Section 3(d) without Good Reason, 30 days after the date on which a Notice of Termination is given, and (iv) if the Employee’s
employment is terminated by the Employee under Section 3(d) with Good Reason, the date on which a Notice of Termination is given after the end of the Cure Period. Notwithstanding the foregoing, in the event that the Employee gives a Notice of
Termination to the Company, the Company may unilaterally accelerate the Date of Termination and such acceleration shall not result in a termination by the Company for purposes of this Agreement. 

4.    Compensation Upon Termination. 

(a)    Termination Generally. If the Employee’s employment with the Company is terminated for any reason, the
Company shall pay or provide to the Employee (or to his authorized representative or estate) (i) any Base Salary earned through the Date of Termination, unpaid expense reimbursements (subject to, and in accordance with, Section 2(c) of
this Agreement) on or before the time required by law but in no event more than 30 days after the Employee’s Date of Termination; and (ii) any vested benefits the Employee may have under any employee benefit plan of the Company through the
Date of Termination, which vested benefits shall be paid and/or provided in accordance with the terms of such employee benefit plans (collectively, the “Accrued Benefit”). 

(b)    Termination by the Company Without Cause or by the Employee with Good Reason. During the Term, if the
Employee’s employment is terminated by the Company without Cause as provided in Section 3(c), or the Employee terminates his employment for Good Reason as provided in Section 3(d), then the Company shall pay the Employee his Accrued
Benefit. In addition, subject to the Employee signing a separation agreement containing, among other provisions, a general release of claims in favor of the Company and related persons and entities, confidentiality, return of property and non-disparagement, in a form and manner satisfactory to the Company (the “Separation Agreement and Release”) and the Separation Agreement and Release becoming irrevocable and fully effective, all
within 60 days after the Date of Termination (or such shorter time period provided in the Separation Agreement and Release), if the Employee was participating in the Company’s group health plan immediately prior to the Date of Termination and
elects COBRA health continuation, then the Company shall pay to the Employee a monthly cash payment for twelve (12) months or the Employee’s COBRA health continuation period, whichever ends earlier, in an amount equal to the monthly
employer contribution that the Company would have made to provide health insurance to the Employee if the Employee had remained employed by the Company. 

5.    Change in Control Payment. The provisions of this Section 5 set forth certain terms of an agreement
reached between the Employee and the Company regarding the Employee’s rights and obligations upon the occurrence of a Change in Control of the Company. These provisions are intended to assure and encourage in advance the Employee’s
continued attention and dedication to his assigned duties and his objectivity during the pendency and after the occurrence of any such event. These provisions shall apply in lieu of, and expressly supersede, the provisions of Section 4(b)
regarding severance pay and benefits upon a 

  
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termination of employment, if such termination of employment occurs within twelve (12) months after the occurrence of the first event constituting a Change in Control. These provisions shall
terminate and be of no further force or effect beginning twelve (12) months after the occurrence of a Change in Control. 

(a)    Change in Control. During the Term, if within twelve (12) months after a Change in Control, the
Employee’s employment is terminated by the Company without Cause as provided in Section 3(c) or the Employee terminates his employment for Good Reason as provided in Section 3(d), then, subject to the signing of the Separation
Agreement and Release by the Employee and the Separation Agreement and Release becoming irrevocable and fully effective, all within 60 days after the Date of Termination (or such shorter time period provided in the Separation Agreement and Release):

 (i)    notwithstanding anything to the contrary in any applicable option agreement or stock-based
award agreement, all time-based stock options and other time-based stock-based awards held by the Employee (the “Time-Based Equity Awards”) shall immediately accelerate and become fully exercisable or nonforfeitable as of the later of
(x) the Date of Termination or (y) the Effective Date of the Separation Agreement and Release (the “Accelerated Vesting Date”); provided that any termination or forfeiture of the unvested portion of such Time-Based Equity
Awards that would otherwise occur on the Date of Termination in the absence of this Agreement will be delayed until the Effective Date of the Separation Agreement and Release and will only occur if the vesting pursuant to this subsection does not
occur due to the absence of the Separation Agreement and Release becoming fully effective within the time period set forth therein. Notwithstanding the foregoing, no additional vesting of the Time-Based Equity Awards shall occur during the period
between the Executive’s Date of Termination and the Accelerated Vesting Date; and 
 (ii)     if the
Employee was participating in the Company’s group health plan immediately prior to the Date of Termination and elects COBRA health continuation, then the Company shall pay to the Employee a monthly cash payment for twelve (12) months or
the Employee’s COBRA health continuation period, whichever ends earlier, in an amount equal to the monthly employer contribution that the Company would have made to provide health insurance to the Employee if the Employee had remained employed
by the Company; and 
 (iii)    The amounts payable under Section 5(a)(ii) shall be paid or commence
to be paid within 60 days after the Date of Termination; provided, however, that if the 60-day period begins in one calendar year and ends in a second calendar year, such payment shall be paid or commence to
be paid in the second calendar year by the last day of such 60-day period. 

(b)    Additional Limitation. 

(i)    Anything in this Agreement to the contrary notwithstanding, in the event that the amount of any
compensation, payment or distribution by the Company to or for the benefit of the Employee, whether paid or payable or distributed or distributable 

  
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pursuant to the terms of this Agreement or otherwise, calculated in a manner consistent with Section 280G of the Internal Revenue Code of 1986, as amended (the “Code”) and
the applicable regulations thereunder (the “Aggregate Payments”), would be subject to the excise tax imposed by Section 4999 of the Code, then the Aggregate Payments shall be reduced (but not below zero) so that the sum of all
of the Aggregate Payments shall be $1.00 less than the amount at which the Employee becomes subject to the excise tax imposed by Section 4999 of the Code; provided that such reduction shall only occur if it would result in the Employee
receiving a higher After Tax Amount (as defined below) than the Employee would receive if the Aggregate Payments were not subject to such reduction. In such event, the Aggregate Payments shall be reduced in the following order, in each case, in
reverse chronological order beginning with the Aggregate Payments that are to be paid the furthest in time from consummation of the transaction that is subject to Section 280G of the Code: (1) cash payments not subject to Section 409A
of the Code; (2) cash payments subject to Section 409A of the Code; (3) equity-based payments and acceleration; and (4) non-cash forms of benefits; provided that in the case of all the
foregoing Aggregate Payments all amounts or payments that are not subject to calculation under Treas. Reg. §1.280G-1, Q&A-24(b) or (c) shall be reduced
before any amounts that are subject to calculation under Treas. Reg. §1.280G-1, Q&A-24(b) or (c). 

(ii)    For purposes of this Section 5(b), the “After Tax Amount” means the amount of the
Aggregate Payments less all federal, state, and local income, excise and employment taxes imposed on the Employee as a result of the Employee’s receipt of the Aggregate Payments. For purposes of determining the After Tax Amount, the Employee
shall be deemed to pay federal income taxes at the highest marginal rate of federal income taxation applicable to individuals for the calendar year in which the determination is to be made, and state and local income taxes at the highest marginal
rates of individual taxation in each applicable state and locality, net of the maximum reduction in federal income taxes which could be obtained from deduction of such state and local taxes. 

(iii)    The determination as to whether a reduction in the Aggregate Payments shall be made pursuant to
Section 5(b)(i) shall be made by a nationally recognized accounting firm selected by the Company (the “Accounting Firm”), which shall provide detailed supporting calculations both to the Company and the Employee within 15
business days of the Date of Termination, if applicable, or at such earlier time as is reasonably requested by the Company or the Employee. Any determination by the Accounting Firm shall be binding upon the Company and the Employee. 

(c)    Definitions. For purposes of this Section 5, the following terms shall have the following meanings: 

“Change in Control” shall mean any of the following: 

(i)    any “person,” as such term is used in Sections 13(d) and 14(d) of the Securities Exchange
Act of 1934, as amended (the “Act”) (other than the Company, any of its subsidiaries, or any trustee, fiduciary or other person or entity holding securities under any employee benefit plan or trust of the Company or any of its
subsidiaries), 

  
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together with all “affiliates” and “associates” (as such terms are defined in Rule 12b-2 under the Act) of such person, shall become
the “beneficial owner” (as such term is defined in Rule 13d-3 under the Act), directly or indirectly, of securities of the Company representing 50 percent or more of the combined voting power of
the Company’s then outstanding securities having the right to vote in an election of the Board (“Voting Securities”) (in such case other than as a result of an acquisition of securities directly from the Company); or 

(ii)    the date a majority of the members of the Board is replaced during any 12-month period by directors whose appointment or election is not endorsed by a majority of the members of the Board before the date of the appointment or election; or 

(iii)    the consummation of (A) any consolidation or merger of the Company where the stockholders of
the Company, immediately prior to the consolidation or merger, would not, immediately after the consolidation or merger, beneficially own (as such term is defined in Rule 13d-3 under the Act), directly or
indirectly, shares representing in the aggregate more than 50 percent of the voting shares of the Company issuing cash or securities in the consolidation or merger (or of its ultimate parent corporation, if any), or (B) any sale or other
transfer (in one transaction or a series of transactions contemplated or arranged by any party as a single plan) of all or substantially all of the assets of the Company and its affiliates on a consolidated basis. 

Notwithstanding the foregoing, a “Change in Control” shall not be deemed to have occurred for purposes of the foregoing clause
(i) solely as the result of an acquisition of securities by the Company which, by reducing the number of shares of Voting Securities outstanding, increases the proportionate number of Voting Securities beneficially owned by any person to
50 percent or more of the combined voting power of all of the then outstanding Voting Securities; provided, however, that if any person referred to in this sentence shall thereafter become the beneficial owner of any additional shares of Voting
Securities (other than pursuant to a stock split, stock dividend, or similar transaction or as a result of an acquisition of securities directly from the Company) and immediately thereafter beneficially owns 50 percent or more of the combined
voting power of all of the then outstanding Voting Securities, then a “Change in Control” shall be deemed to have occurred for purposes of the foregoing clause (i). 

6.    Section 409A. 

(a)    Anything in this Agreement to the contrary notwithstanding, if at the time of the Employee’s separation from
service within the meaning of Section 409A of the Code, the Company determines that the Employee is a “specified employee” within the meaning of Section 409A(a)(2)(B)(i) of the Code, then to the extent any payment or benefit that
the Employee becomes entitled to under this Agreement on account of the Employee’s separation from service would be considered deferred compensation otherwise subject to the 20 percent additional tax imposed pursuant to
Section 409A(a) of the Code as a result of the application of Section 409A(a)(2)(B)(i) of the Code, such payment shall not be payable and such benefit shall not be provided until the date that is the earlier of (A) six months and one
day after the Employee’s separation from service, or (B) the Employee’s death. If any such delayed cash payment is otherwise payable on an installment basis, the first payment shall include a
catch-up payment covering amounts that would otherwise have been paid during the six-month period but for the application of this provision, and the balance of the
installments shall be payable in accordance with their original schedule. 

  
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 (b)    All in-kind benefits
provided and expenses eligible for reimbursement under this Agreement shall be provided by the Company or incurred by the Employee during the time periods set forth in this Agreement. All reimbursements shall be paid as soon as administratively
practicable, but in no event shall any reimbursement be paid after the last day of the taxable year following the taxable year in which the expense was incurred. The amount of in-kind benefits provided or
reimbursable expenses incurred in one taxable year shall not affect the in-kind benefits to be provided or the expenses eligible for reimbursement in any other taxable year (except for any lifetime or other
aggregate limitation applicable to medical expenses). Such right to reimbursement or in-kind benefits is not subject to liquidation or exchange for another benefit. 

(c)    To the extent that any payment or benefit described in this Agreement constitutes
“non-qualified deferred compensation” under Section 409A of the Code, and to the extent that such payment or benefit is payable upon the Employee’s termination of employment, then such
payments or benefits shall be payable only upon the Employee’s “separation from service.” The determination of whether and when a separation from service has occurred shall be made in accordance with the presumptions set forth in
Treasury Regulation Section 1.409A-1(h). 
 (d)    The parties intend that
this Agreement will be administered in accordance with Section 409A of the Code. To the extent that any provision of this Agreement is ambiguous as to its compliance with Section 409A of the Code, the provision shall be read in such a
manner so that all payments hereunder comply with Section 409A of the Code. Each payment pursuant to this Agreement is intended to constitute a separate payment for purposes of Treasury Regulation
Section 1.409A-2(b)(2). The parties agree that this Agreement may be amended, as reasonably requested by either party, and as may be necessary to fully comply with Section 409A of the Code and all
related rules and regulations in order to preserve the payments and benefits provided hereunder without additional cost to either party. 

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

7.    Confidential Information, Noncompetition and Cooperation. The terms of the Employee Non-Competition, Non-Solicitation, Confidentiality and Assignment Agreement (the “Restrictive Covenant Agreement”), between the Company and the Employee, attached
hereto as Exhibit A, shall continue to be in full force and effect and are incorporated by reference in this Agreement. The Employee hereby reaffirms the terms of the Restrictive Covenant Agreement as material terms of this Agreement. 

(a)    Litigation and Regulatory Cooperation. During and after the Employee’s employment, the Employee shall
cooperate fully with the Company in the defense or prosecution 

  
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of any claims or actions now in existence or which may be brought in the future against or on behalf of the Company which relate to events or occurrences that transpired while the Employee was
employed by the Company. The Employee’s full cooperation in connection with such claims or actions shall include, but not be limited to, being available to meet with counsel to prepare for discovery or trial and to act as a witness on behalf of
the Company at mutually convenient times. During and after the Employee’s employment, the Employee also shall cooperate fully with the Company in connection with any investigation or review of any federal, state or local regulatory authority as
any such investigation or review relates to events or occurrences that transpired while the Employee was employed by the Company. The Company shall reimburse the Employee for any reasonable out-of-pocket expenses incurred in connection with the Employee’s performance of obligations pursuant to this Section 7(a). 

(b)    Relief. The Employee agrees that it would be difficult to measure any damages caused to the Company which
might result from any breach by the Employee of the promises set forth in this Section 7, and that in any event money damages would be an inadequate remedy for any such breach. Accordingly, subject to Section 8 of this Agreement, the
Employee agrees that if the Employee breaches, or proposes to breach, any portion of this Agreement, the Company shall be entitled, in addition to all other remedies that it may have, to an injunction or other appropriate equitable relief to
restrain any such breach without showing or proving any actual damage to the Company. In addition, in the event the Employee breaches this Section 7 during a period when he is receiving severance benefits pursuant to Section 4 or
Section 5 hereof, the Company shall have the right to suspend or terminate such severance benefits. Such suspension or termination shall not limit the Company’s other options with respect to relief for such breach and shall not relieve the
Employee of his duties under this Agreement. 
 (c)    Protected Disclosures and Other Protected Action. Nothing
contained in this Agreement limits the Employee’s ability to communicate with any federal, state or local governmental agency or commission, including to provide documents or other information, without notice to the Company. 

8.    Arbitration of Disputes. Any controversy or claim arising out of or relating to this Agreement or the breach
thereof or otherwise arising out of the Employee’s employment or the termination of that employment (including, without limitation, any claims of unlawful employment discrimination whether based on age or otherwise) shall, to the fullest extent
permitted by law, be settled by arbitration in any forum and form agreed upon by the parties or, in the absence of such an agreement, under the auspices of the American Arbitration Association (“AAA”) in Boston, Massachusetts in
accordance with the Employment Dispute Resolution Rules of the AAA, including, but not limited to, the rules and procedures applicable to the selection of arbitrators. In the event that any person or entity other than the Employee or the Company may
be a party with regard to any such controversy or claim, such controversy or claim shall be submitted to arbitration subject to such other person or entity’s agreement. Judgment upon the award rendered by the arbitrator may be entered in any
court having jurisdiction thereof. This Section 8 shall be specifically enforceable. Notwithstanding the foregoing, this Section 8 shall not preclude either party from pursuing a court action for the sole purpose of obtaining a temporary
restraining order or a preliminary injunction in circumstances in which such relief is appropriate; provided that any other relief shall be pursued through an arbitration proceeding pursuant to this Section 8. 

  
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 9.    Consent to Jurisdiction. To the extent that any court
action is permitted consistent with or to enforce Section 8 of this Agreement, the parties hereby consent to the jurisdiction of the Superior Court of the Commonwealth of Massachusetts and the United States District Court for the District of
Massachusetts. Accordingly, with respect to any such court action, the Employee (a) submits to the personal jurisdiction of such courts; (b) consents to service of process; and (c) waives any other requirement (whether imposed by
statute, rule of court, or otherwise) with respect to personal jurisdiction or service of process. 

10.    Integration. This Agreement, including the Restrictive Covenant Agreement, constitutes the entire agreement
between the parties with respect to the subject matter hereof and supersedes all prior agreements between the parties concerning such subject matter, including the Prior Agreement. 

11.    Withholding. All payments made by the Company to the Employee under this Agreement shall be net of any tax
or other amounts required to be withheld by the Company under applicable law. 
 12.    Successor to the
Employee. This Agreement shall inure to the benefit of and be enforceable by the Employee’s personal representatives, executors, administrators, heirs, distributees, devisees and legatees. In the event of the Employee’s death after his
termination of employment but prior to the completion by the Company of all payments due to him under this Agreement, the Company shall continue such payments to the Employee’s beneficiary designated in writing to the Company prior to his death
(or to his estate, if the Employee fails to make such designation). 
 13.    Enforceability. If any portion or
provision of this Agreement (including, without limitation, any portion or provision of any section of this Agreement) shall to any extent be declared illegal or unenforceable by a court of competent jurisdiction, then the remainder of this
Agreement, or the application of such portion or provision in circumstances other than those as to which it is so declared illegal or unenforceable, shall not be affected thereby, and each portion and provision of this Agreement shall be valid and
enforceable to the fullest extent permitted by law. 
 14.    Survival. The provisions of this Agreement shall
survive the termination of this Agreement and/or the termination of the Employee’s employment to the extent necessary to effectuate the terms contained herein. 

15.    Waiver. No waiver of any provision hereof shall be effective unless made in writing and signed by the
waiving party. The failure of any party to require the performance of any term or obligation of this Agreement, or the waiver by any party of any breach of this Agreement, shall not prevent any subsequent enforcement of such term or obligation or be
deemed a waiver of any subsequent breach. 
 16.    Notices. Any notices, requests, demands and other
communications provided for by this Agreement shall be sufficient if in writing and delivered in person or sent by a nationally recognized overnight courier service or by registered or certified mail, postage prepaid, return receipt requested, to
the Employee at the last address the Employee has filed in writing with the Company or, in the case of the Company, at its main offices, attention of the Board. 

  
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 17.    Amendment. This Agreement may be amended or modified only
by a written instrument signed by the Employee and by a duly authorized representative of the Company. 

18.    Governing Law. This is a Massachusetts contract and shall be construed under and be governed in all respects
by the laws of the Commonwealth of Massachusetts without giving effect to the conflict of laws principles thereof. 

19.    Counterparts. This Agreement may be executed in any number of counterparts, each of which when so executed
and delivered shall be taken to be an original; but such counterparts shall together constitute one and the same document. 

20.    Successor to Company. The Company shall require any successor (whether direct or indirect, by purchase,
merger, consolidation or otherwise) to all or substantially all of the business or assets of the Company expressly to assume and agree to perform this Agreement to the same extent that the Company would be required to perform it if no succession had
taken place. Failure of the Company to obtain an assumption of this Agreement at or prior to the effectiveness of any succession shall be a material breach of this Agreement. 

21.    Gender Neutral. Wherever used herein, a pronoun in the masculine gender shall be considered as including the
feminine gender unless the context clearly indicates otherwise. 
 IN WITNESS WHEREOF, the parties have executed this Agreement effective on
the date and year first above written. 
  

			
	KALEIDO BIOSCIENCES, INC.
		
	By:	 	Noubar B. Afeyan
	Its:	 	Director

  

	
	EMPLOYEE
	
	/s/ Michael Bonney
	MICHAEL BONNEY

  
 11EX-10.9

 Exhibit 10.9 

EXECUTION VERSION 

KALEIDO BIOSCIENCES, INC. 

EMPLOYMENT AGREEMENT 

This Employment Agreement (“Agreement”) is made as of January 24, 2019, between Kaleido Biosciences, Inc., a Delaware
corporation (the “Company”), and Alison Lawton (the “Employee”) and is effective as of the closing of the Company’s first underwritten public offering of its equity securities pursuant to an effective
registration statement under the Securities Act of 1933, as amended (the “Effective Date”). 
 WHEREAS, the Company and the
Employee are parties to an offer letter, dated November 16, 2017, as amended by letter dated August 16, 2018 (the “Prior Agreement”); and 

WHEREAS, the parties intend to replace the Prior Agreement with this Agreement, effective as of the Effective Date. 

NOW, THEREFORE, in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties agree as follows: 
 1.    Employment. 

(a)    Term. The term of this Agreement shall commence on the Effective Date and continue until terminated in
accordance with the provisions hereof (the “Term”). The Employee’s employment with the Company will continue to be “at will,” meaning that the Employee’s employment may be terminated by the Company or the
Employee at any time and for any reason subject to the terms of this Agreement. 
 (b)    Position and Duties.
During the Term, the Employee shall serve as the Chief Executive Officer (CEO) of the Company, and shall have such duties and authorities as may from time to time be prescribed by the Company’s Board of Directors (the “Board”). The
Employee shall devote her full working time and efforts to the business and affairs of the Company. Notwithstanding the foregoing, the Employee may serve on other boards of directors, with the advance written approval of the Board, or engage in
religious, charitable or other community activities as long as such services and activities do not interfere with the Executive’s performance of her duties to the Company as provided in this Agreement. 

2.    Compensation and Related Matters. 

(a)    Base Salary. The Company shall continue the Employee’s base salary at its current rate, subject to
annual review by the Company’s Board of Directors (“Board”). The base salary in effect at any given time is referred to herein as “Base Salary.” The Base Salary shall be payable in a manner that is consistent with the
Company’s usual payroll practices. 
 (b)    Incentive Compensation. During the Term, the Employee shall be
eligible to receive cash incentive compensation as determined by the Board or the Compensation Committee (the “Compensation Committee”) from time to time, in accordance with Company’s bonus program. Except as otherwise provided
in the Company’s bonus program, to earn incentive compensation, the employee must be employed by the Company on the day such incentive compensation is paid. 

 (c)    Equity. The equity awards held by the Employee shall be
governed by the terms and conditions of the Company’s applicable equity incentive plan(s) and the applicable award agreement(s) governing the terms of such equity awards held by the Executive (collectively, the “Equity Documents”).

 (d)    Expenses. The Employee shall be entitled to receive prompt reimbursement for all reasonable expenses
incurred by her during the Term in performing services hereunder, in accordance with the policies and procedures then in effect and established by the Company. 

(e)    Vacation. During the Term, the Employee shall be entitled to paid vacation in accordance with the
Company’s policies and procedures. The Employee shall also be entitled to all paid holidays given by the Company in accordance with the policies and procedures then in effect and established by the Company. 

(f)    Other Benefits. During the Term, the Employee shall be eligible to participate in or receive benefits under
the Company’s employee benefit plans in effect from time to time, subject to the terms of such plans. 

3.    Termination. During the Term, the Employee’s employment hereunder may be terminated without any breach
of this Agreement under the following circumstances: 
 (a)    Death. The Employee’s employment hereunder
shall terminate upon her death. 
 (b)    Disability. The Company may terminate the Employee’s employment if
she is disabled and unable to perform the essential functions of the Employee’s then existing position or positions under this Agreement with or without reasonable accommodation for a period of 180 days (which need not be consecutive) in any 12-month period. If any question shall arise as to whether during any period the Employee is disabled so as to be unable to perform the essential functions of the Employee’s then existing position or positions
with or without reasonable accommodation, the Employee may, and at the request of the Company shall, submit to the Company a certification in reasonable detail by a physician selected by the Company to whom the Employee or the Employee’s
guardian has no reasonable objection as to whether the Employee is so disabled or how long such disability is expected to continue, and such certification shall for the purposes of this Agreement be conclusive of the issue. The Employee shall
cooperate with any reasonable request of the physician in connection with such certification. If such question shall arise and the Employee shall fail to submit such certification, the Company’s determination of such issue shall be binding on
the Employee. Nothing in this Section 3(b) shall be construed to waive the Employee’s rights, if any, under existing law including, without limitation, the Family and Medical Leave Act of 1993, 29 U.S.C. §2601 et seq. and the
Americans with Disabilities Act, 42 U.S.C. §12101 et seq. 

  
 2 

 (c)    Termination by Company for Cause. The Company may
terminate the Employee’s employment hereunder for Cause. For purposes of this Agreement, “Cause” shall mean: (i) conduct by the Employee constituting a material act of misconduct in connection with the performance of her duties,
including, without limitation, misappropriation of funds or property of the Company or any of its subsidiaries or affiliates other than the occasional, customary and de minimis use of Company property for personal purposes; (ii) the commission
by the Employee of any felony or a misdemeanor involving moral turpitude, deceit, dishonesty or fraud, or any conduct by the Employee that would reasonably be expected to result in material injury or reputational harm to the Company or any of its
subsidiaries or affiliates if she were retained in her position; (iii) continued non-performance by the Employee of her duties hereunder (other than by reason of the Employee’s physical or mental
illness, incapacity or disability) which has continued for more than 30 days following written notice of such non-performance from the Board; (iv) a breach by the Employee of any of the provisions
contained in Section 7 of this Agreement; (v) a material violation by the Employee of the Company’s written employment policies; or (vi) failure to cooperate with a bona fide internal investigation or an investigation by
regulatory or law enforcement authorities, after being instructed by the Company to cooperate, or the willful destruction or failure to preserve documents or other materials known to be relevant to such investigation or the inducement of others to
fail to cooperate or to produce documents or other materials in connection with such investigation. 

(d)    Termination Without Cause. The Company may terminate the Employee’s employment hereunder at any time
without Cause. Any termination by the Company of the Employee’s employment under this Agreement which does not constitute a termination for Cause under Section 3(b) and does not result from the death of the Employee under Section 3(a)
or the disability of the Employee under Section 3(b) shall be deemed a termination without Cause. 

(e)    Termination by the Employee. The Employee may terminate her employment hereunder at any time for any reason,
including but not limited to Good Reason. For purposes of this Agreement, “Good Reason” shall mean that the Employee has complied with the “Good Reason Process” (hereinafter defined) following the occurrence of any of the
following events: (i) a material diminution in the Employee’s responsibilities, authority or duties, provided that the hiring by the Company of any Company officers with customary responsibilities, authority or duties (including any CBO,
CFO or CMO), will not constitute any such material diminution; (ii) a material diminution in the Employee’s Base Salary except for across-the-board salary
reductions based on the Company’s financial performance similarly affecting all or substantially all senior management employees of the Company; (iii) a material change in the geographic location at which the Employee provides services to
the Company, except for required travel for the Company’s business; or (iv) the material breach of this Agreement by the Company. “Good Reason Process” shall mean that (i) the Employee reasonably determines in good faith
that a “Good Reason” condition has occurred; (ii) the Employee notifies the Company in writing of the first occurrence of the Good Reason condition within 60 days of the first occurrence of such condition; (iii) the Employee
cooperates in good faith with the Company’s efforts, for a period not less than 30 days following such notice (the “Cure Period”), to remedy the condition; (iv) notwithstanding such efforts, the Good Reason condition continues to
exist; and (v) the Employee terminates her employment within 60 days after the end of the Cure Period. If the Company cures the Good Reason condition during the Cure Period, Good Reason shall be deemed not to have occurred. 

  
 3 

 (f)    Notice of Termination. Except for termination as specified
in Section 3(a), any termination of the Employee’s employment by the Company or any such termination by the Employee shall be communicated by written Notice of Termination to the other party hereto. For purposes of this Agreement, a
“Notice of Termination” shall mean a notice which shall indicate the specific termination provision in this Agreement relied upon. 

(g)    Date of Termination. “Date of Termination” shall mean: (i) if the Employee’s employment
is terminated by her death, the date of her death; (ii) if the Employee’s employment is terminated by the Company on account of the Employee’s disability under Section 3(b) or by the Company for Cause under Section 3(c), the
date on which a Notice of Termination is given; (iii) if the Employee’s employment is terminated by the Employee under Section 3(e) without Good Reason, 30 days after the date on which a Notice of Termination is given, and
(iv) if the Employee’s employment is terminated by the Employee under Section 3(e) with Good Reason, the date on which a Notice of Termination is given after the end of the Cure Period. Notwithstanding the foregoing, in the event that
the Employee gives a Notice of Termination to the Company, the Company may unilaterally accelerate the Date of Termination and such acceleration shall not result in a termination by the Company for purposes of this Agreement. 

4.    Compensation Upon Termination. 

(a)    Termination Generally. If the Employee’s employment with the Company is terminated for any reason, the
Company shall pay or provide to the Employee (or to her authorized representative or estate) (i) any Base Salary earned through the Date of Termination, unpaid expense reimbursements (subject to, and in accordance with, Section 2(d) of
this Agreement) and unused vacation that accrued through the Date of Termination on or before the time required by law but in no event more than 30 days after the Employee’s Date of Termination; and (ii) any vested benefits the Employee
may have under any employee benefit plan of the Company through the Date of Termination, which vested benefits shall be paid and/or provided in accordance with the terms of such employee benefit plans (collectively, the “Accrued
Benefit”). 
 (b)    Termination by the Company Without Cause or by the Employee with Good Reason. During
the Term, if the Employee’s employment is terminated by the Company without Cause as provided in Section 3(d), or the Employee terminates her employment for Good Reason as provided in Section 3(e), then the Company shall pay the
Employee her Accrued Benefit. In addition, subject to the Employee signing a separation agreement containing, among other provisions, a general release of claims in favor of the Company and related persons and entities, confidentiality, return of
property and non-disparagement, in a form and manner satisfactory to the Company (the “Separation Agreement and Release”) and the Separation Agreement and Release becoming irrevocable and
fully effective, all within 60 days after the Date of Termination (or such shorter time period provided in the Separation Agreement and Release): 

(i)    The Company shall pay the Employee an amount equal to twelve (12) months of the Employee’s
Base Salary plus an amount equal to the incentive compensation paid to the Employee pursuant to Section 2(b) above during the fiscal year prior to the year of termination (the “Severance Amount”). Notwithstanding the foregoing,
if the Employee breaches any of the provisions contained in Section 7 of this Agreement, all payments of the Severance Amount shall immediately cease; 

  
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 (ii)    Notwithstanding any provision in the Equity
Documents to the contrary, and subject to the Employee’s compliance with the provisions contained in Section 7 of this Agreement, the Company shall extend the period during which the Employee can exercise any of her vested options to
purchase stock in the Company until the anniversary of the Employee’s Date of Termination; 

(iii)    If the Employee was participating in the Company’s group health plan immediately prior to the
Date of Termination and elects COBRA health continuation, then the Company shall pay to the Employee a monthly cash payment for twelve (12) months or the Employee’s COBRA health continuation period, whichever ends earlier, in an amount
equal to the monthly employer contribution that the Company would have made to provide health insurance to the Employee if the Employee had remained employed by the Company; and 

(iv)    the amounts payable under Section 4(b)(i) and (iii) shall be paid out in substantially
equal installments in accordance with the Company’s payroll practice commencing within 60 days after the Date of Termination; provided, however, that if the 60-day period begins in one calendar
year and ends in a second calendar year, the Severance Amount shall begin to be paid in the second calendar year by the last day of such 60-day period; provided, further, that the initial payment shall include
a catch-up payment to cover amounts retroactive to the day immediately following the Date of Termination. Each payment pursuant to this Agreement is intended to constitute a separate payment for purposes of
Treasury Regulation Section 1.409A-2(b)(2). 
 5.    Change in Control
Payment. The provisions of this Section 5 set forth certain terms of an agreement reached between the Employee and the Company regarding the Employee’s rights and obligations upon the occurrence of a Change in Control of the Company.
These provisions are intended to assure and encourage in advance the Employee’s continued attention and dedication to her assigned duties and her objectivity during the pendency and after the occurrence of any such event. These provisions shall
apply in lieu of, and expressly supersede, the provisions of Section 4(b) regarding severance pay and benefits upon a termination of employment, if such termination of employment occurs within fifteen (15) months after the occurrence of
the first event constituting a Change in Control. These provisions shall terminate and be of no further force or effect beginning fifteen (15) months after the occurrence of a Change in Control. 

  
 5 

 (a)    Change in Control. During the Term, if within fifteen
(15) months after a Change in Control, the Employee’s employment is terminated by the Company without Cause as provided in Section 3(d) or the Employee terminates her employment for Good Reason as provided in Section 3(e), then,
subject to the signing of the Separation Agreement and Release by the Employee and the Separation Agreement and Release becoming irrevocable and fully effective, all within 60 days after the Date of Termination (or such shorter time period provided
in the Separation Agreement and Release): 
 (i)    the Company shall pay the Employee a lump sum in cash
in an amount equal to 1.5 times the sum of (A) the Employee’s current Base Salary (or the Employee’s Base Salary in effect immediately prior to the Change in Control, if higher), plus (B) the target incentive compensation
established for the Employee in the fiscal year of termination; and if no such target has been established, the target incentive compensation established for the Employee in the fiscal year prior to the year of termination; 

(ii)    notwithstanding anything to the contrary in any applicable option agreement or stock-based award
agreement, all stock options and other stock-based awards held by the Employee (the “Equity Awards”) shall immediately accelerate and become fully exercisable or nonforfeitable as of the later of (x) the Date of Termination or
(y) the Effective Date of the Separation Agreement and Release (the “Accelerated Vesting Date”); provided that any termination or forfeiture of the unvested portion of such Equity Awards that would otherwise occur on the Date
of Termination in the absence of this Agreement will be delayed until the Effective Date of the Separation Agreement and Release and will only occur if the vesting pursuant to this subsection does not occur due to the absence of the Separation
Agreement and Release becoming fully effective within the time period set forth therein. Notwithstanding the foregoing, no additional vesting of the Equity Awards shall occur during the period between the Employee’s Date of Termination and the
Accelerated Vesting Date; and 
 (iii)     if the Employee was participating in the Company’s group
health plan immediately prior to the Date of Termination and elects COBRA health continuation, then the Company shall pay to the Employee a monthly cash payment for eighteen (18) months or the Employee’s COBRA health continuation period,
whichever ends earlier, in an amount equal to the monthly employer contribution that the Company would have made to provide health insurance to the Employee if the Employee had remained employed by the Company; and 

(iv)    The amounts payable under Section 5(a)(i) and (iii) shall be paid or commence to be paid
within 60 days after the Date of Termination; provided, however, that if the 60-day period begins in one calendar year and ends in a second calendar year, such payment shall be paid or commence to be paid in
the second calendar year by the last day of such 60-day period. 

(b)    Additional Limitation. 

(i)    Anything in this Agreement to the contrary notwithstanding, in the event that the amount of any
compensation, payment or distribution by the Company to or for the benefit of the Employee, whether paid or payable or distributed or distributable pursuant to the terms of this Agreement or otherwise, calculated in a manner consistent with
Section 280G of the Internal Revenue Code of 1986, as amended (the “Code”) and 

  
 6 

 
the applicable regulations thereunder (the “Aggregate Payments”), would be subject to the excise tax imposed by Section 4999 of the Code, then the Aggregate Payments shall
be reduced (but not below zero) so that the sum of all of the Aggregate Payments shall be $1.00 less than the amount at which the Employee becomes subject to the excise tax imposed by Section 4999 of the Code; provided that such reduction shall
only occur if it would result in the Employee receiving a higher After Tax Amount (as defined below) than the Employee would receive if the Aggregate Payments were not subject to such reduction. In such event, the Aggregate Payments shall be reduced
in the following order, in each case, in reverse chronological order beginning with the Aggregate Payments that are to be paid the furthest in time from consummation of the transaction that is subject to Section 280G of the Code: (1) cash
payments not subject to Section 409A of the Code; (2) cash payments subject to Section 409A of the Code; (3) equity-based payments and acceleration; and (4) non-cash forms of benefits;
provided that in the case of all the foregoing Aggregate Payments all amounts or payments that are not subject to calculation under Treas. Reg. §1.280G-1, Q&A-24(b) or (c) shall be reduced before
any amounts that are subject to calculation under Treas. Reg. §1.280G-1, Q&A-24(b) or (c). 

(ii)    For purposes of this Section 5(b), the “After Tax Amount” means the amount of the
Aggregate Payments less all federal, state, and local income, excise and employment taxes imposed on the Employee as a result of the Employee’s receipt of the Aggregate Payments. For purposes of determining the After Tax Amount, the Employee
shall be deemed to pay federal income taxes at the highest marginal rate of federal income taxation applicable to individuals for the calendar year in which the determination is to be made, and state and local income taxes at the highest marginal
rates of individual taxation in each applicable state and locality, net of the maximum reduction in federal income taxes which could be obtained from deduction of such state and local taxes. 

(iii)    The determination as to whether a reduction in the Aggregate Payments shall be made pursuant to
Section 5(b)(i) shall be made by a nationally recognized accounting firm selected by the Company (the “Accounting Firm”), which shall provide detailed supporting calculations both to the Company and the Employee within 15
business days of the Date of Termination, if applicable, or at such earlier time as is reasonably requested by the Company or the Employee. Any determination by the Accounting Firm shall be binding upon the Company and the Employee. 

(c)    Definitions. For purposes of this Section 5, the following terms shall have the following meanings:

 “Change in Control” shall mean any of the following: 

(i)    any “person,” as such term is used in Sections 13(d) and 14(d) of the Securities Exchange
Act of 1934, as amended (the “Act”) (other than the Company, any of its subsidiaries, or any trustee, fiduciary or other person or entity holding securities under any employee benefit plan or trust of the Company or any of its
subsidiaries), together with all “affiliates” and “associates” (as such terms are defined in Rule 12b-2 under the Act) of such person, shall become the “beneficial owner” (as such
term is 

  
 7 

 
defined in Rule 13d-3 under the Act), directly or indirectly, of securities of the Company representing 50 percent or more of the combined voting
power of the Company’s then outstanding securities having the right to vote in an election of the Board (“Voting Securities”) (in such case other than as a result of an acquisition of securities directly from the Company); or

 (ii)    the date a majority of the members of the Board is replaced during any 12-month period by directors whose appointment or election is not endorsed by a majority of the members of the Board before the date of the appointment or election; or 

(iii)    the consummation of (A) any consolidation or merger of the Company where the stockholders of
the Company, immediately prior to the consolidation or merger, would not, immediately after the consolidation or merger, beneficially own (as such term is defined in Rule 13d-3 under the Act), directly or
indirectly, shares representing in the aggregate more than 50 percent of the voting shares of the Company issuing cash or securities in the consolidation or merger (or of its ultimate parent corporation, if any), or (B) any sale or other
transfer (in one transaction or a series of transactions contemplated or arranged by any party as a single plan) of all or substantially all of the assets of the Company and its affiliates on a consolidated basis. 

Notwithstanding the foregoing, a “Change in Control” shall not be deemed to have occurred for purposes of the foregoing clause
(i) solely as the result of an acquisition of securities by the Company which, by reducing the number of shares of Voting Securities outstanding, increases the proportionate number of Voting Securities beneficially owned by any person to
50 percent or more of the combined voting power of all of the then outstanding Voting Securities; provided, however, that if any person referred to in this sentence shall thereafter become the beneficial owner of any additional shares of Voting
Securities (other than pursuant to a stock split, stock dividend, or similar transaction or as a result of an acquisition of securities directly from the Company) and immediately thereafter beneficially owns 50 percent or more of the combined
voting power of all of the then outstanding Voting Securities, then a “Change in Control” shall be deemed to have occurred for purposes of the foregoing clause (i). 

6.    Section 409A. 

(a)    Anything in this Agreement to the contrary notwithstanding, if at the time of the Employee’s separation from
service within the meaning of Section 409A of the Code, the Company determines that the Employee is a “specified employee” within the meaning of Section 409A(a)(2)(B)(i) of the Code, then to the extent any payment or benefit that
the Employee becomes entitled to under this Agreement on account of the Employee’s separation from service would be considered deferred compensation otherwise subject to the 20 percent additional tax imposed pursuant to
Section 409A(a) of the Code as a result of the application of Section 409A(a)(2)(B)(i) of the Code, such payment shall not be payable and such benefit shall not be provided until the date that is the earlier of (A) six months and one
day after the Employee’s separation from service, or (B) the Employee’s death. If any such delayed cash payment is otherwise payable on an installment basis, the first payment shall include a
catch-up payment covering amounts that would otherwise have been paid during the six-month period but for the application of this provision, and the balance of the
installments shall be payable in accordance with their original schedule. 

  
 8 

 (b)    All in-kind benefits
provided and expenses eligible for reimbursement under this Agreement shall be provided by the Company or incurred by the Employee during the time periods set forth in this Agreement. All reimbursements shall be paid as soon as administratively
practicable, but in no event shall any reimbursement be paid after the last day of the taxable year following the taxable year in which the expense was incurred. The amount of in-kind benefits provided or
reimbursable expenses incurred in one taxable year shall not affect the in-kind benefits to be provided or the expenses eligible for reimbursement in any other taxable year (except for any lifetime or other
aggregate limitation applicable to medical expenses). Such right to reimbursement or in-kind benefits is not subject to liquidation or exchange for another benefit. 

(c)    To the extent that any payment or benefit described in this Agreement constitutes
“non-qualified deferred compensation” under Section 409A of the Code, and to the extent that such payment or benefit is payable upon the Employee’s termination of employment, then such
payments or benefits shall be payable only upon the Employee’s “separation from service.” The determination of whether and when a separation from service has occurred shall be made in accordance with the presumptions set forth in
Treasury Regulation Section 1.409A-1(h). 
 (d)    The parties intend that
this Agreement will be administered in accordance with Section 409A of the Code. To the extent that any provision of this Agreement is ambiguous as to its compliance with Section 409A of the Code, the provision shall be read in such a
manner so that all payments hereunder comply with Section 409A of the Code. Each payment pursuant to this Agreement is intended to constitute a separate payment for purposes of Treasury Regulation
Section 1.409A-2(b)(2). The parties agree that this Agreement may be amended, as reasonably requested by either party, and as may be necessary to fully comply with Section 409A of the Code and all
related rules and regulations in order to preserve the payments and benefits provided hereunder without additional cost to either party. 

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

7.    Confidential Information, Noncompetition and Cooperation. The terms of the Employee Non-Competition, Non-Solicitation, Confidentiality and Assignment Agreement (the “Restrictive Covenant Agreement”), between the Company and the Employee, attached
hereto as Exhibit A, shall continue to be in full force and effect and are incorporated by reference in this Agreement. The Employee hereby reaffirms the terms of the Restrictive Covenant Agreement as material terms of this Agreement. 

(a)    Litigation and Regulatory Cooperation. During and after the Employee’s employment, the Employee shall
cooperate fully with the Company in the defense or prosecution of any claims or actions now in existence or which may be brought in the future against or on 

  
 9 

 
behalf of the Company which relate to events or occurrences that transpired while the Employee was employed by the Company. The Employee’s full cooperation in connection with such claims or
actions shall include, but not be limited to, being available to meet with counsel to prepare for discovery or trial and to act as a witness on behalf of the Company at mutually convenient times. During and after the Employee’s employment, the
Employee also shall cooperate fully with the Company in connection with any investigation or review of any federal, state or local regulatory authority as any such investigation or review relates to events or occurrences that transpired while the
Employee was employed by the Company. The Company shall reimburse the Employee for any reasonable out-of-pocket expenses incurred in connection with the Employee’s
performance of obligations pursuant to this Section 7(a). 
 (b)    Relief. The Employee agrees that it would
be difficult to measure any damages caused to the Company which might result from any breach by the Employee of the promises set forth in this Section 7, and that in any event money damages would be an inadequate remedy for any such breach.
Accordingly, subject to Section 8 of this Agreement, the Employee agrees that if the Employee breaches, or proposes to breach, any portion of this Agreement, the Company shall be entitled, in addition to all other remedies that it may have, to
an injunction or other appropriate equitable relief to restrain any such breach without showing or proving any actual damage to the Company. In addition, in the event the Employee breaches this Section 7 during a period when she is receiving
severance benefits pursuant to Section 4 or Section 5 hereof, the Company shall have the right to suspend or terminate such severance benefits. Such suspension or termination shall not limit the Company’s other options with respect to
relief for such breach and shall not relieve the Employee of her duties under this Agreement. 
 (c)    Protected
Disclosures and Other Protected Action. Nothing contained in this Agreement limits the Employee’s ability to communicate with any federal, state or local governmental agency or commission, including to provide documents or other
information, without notice to the Company. 
 8.    Arbitration of Disputes. Any controversy or claim arising
out of or relating to this Agreement or the breach thereof or otherwise arising out of the Employee’s employment or the termination of that employment (including, without limitation, any claims of unlawful employment discrimination whether
based on age or otherwise) shall, to the fullest extent permitted by law, be settled by arbitration in any forum and form agreed upon by the parties or, in the absence of such an agreement, under the auspices of the American Arbitration Association
(“AAA”) in Boston, Massachusetts in accordance with the Employment Dispute Resolution Rules of the AAA, including, but not limited to, the rules and procedures applicable to the selection of arbitrators. In the event that any person
or entity other than the Employee or the Company may be a party with regard to any such controversy or claim, such controversy or claim shall be submitted to arbitration subject to such other person or entity’s agreement. Judgment upon the
award rendered by the arbitrator may be entered in any court having jurisdiction thereof. This Section 8 shall be specifically enforceable. Notwithstanding the foregoing, this Section 8 shall not preclude either party from pursuing a court
action for the sole purpose of obtaining a temporary restraining order or a preliminary injunction in circumstances in which such relief is appropriate; provided that any other relief shall be pursued through an arbitration proceeding pursuant to
this Section 8. 

  
 10 

 9.    Consent to Jurisdiction. To the extent that any court
action is permitted consistent with or to enforce Section 8 of this Agreement, the parties hereby consent to the jurisdiction of the Superior Court of the Commonwealth of Massachusetts and the United States District Court for the District of
Massachusetts. Accordingly, with respect to any such court action, the Employee (a) submits to the personal jurisdiction of such courts; (b) consents to service of process; and (c) waives any other requirement (whether imposed by
statute, rule of court, or otherwise) with respect to personal jurisdiction or service of process. 

10.    Integration. This Agreement, including the Restrictive Covenant Agreement, constitutes the entire agreement
between the parties with respect to the subject matter hereof and supersedes all prior agreements between the parties concerning such subject matter, including the Prior Agreement. 

11.    Withholding. All payments made by the Company to the Employee under this Agreement shall be net of any tax
or other amounts required to be withheld by the Company under applicable law. 
 12.    Successor to the
Employee. This Agreement shall inure to the benefit of and be enforceable by the Employee’s personal representatives, executors, administrators, heirs, distributees, devisees and legatees. In the event of the Employee’s death after her
termination of employment but prior to the completion by the Company of all payments due to her under this Agreement, the Company shall continue such payments to the Employee’s beneficiary designated in writing to the Company prior to her death
(or to her estate, if the Employee fails to make such designation). 
 13.    Enforceability. If any portion or
provision of this Agreement (including, without limitation, any portion or provision of any section of this Agreement) shall to any extent be declared illegal or unenforceable by a court of competent jurisdiction, then the remainder of this
Agreement, or the application of such portion or provision in circumstances other than those as to which it is so declared illegal or unenforceable, shall not be affected thereby, and each portion and provision of this Agreement shall be valid and
enforceable to the fullest extent permitted by law. 
 14.    Survival. The provisions of this Agreement shall
survive the termination of this Agreement and/or the termination of the Employee’s employment to the extent necessary to effectuate the terms contained herein. 

15.    Waiver. No waiver of any provision hereof shall be effective unless made in writing and signed by the
waiving party. The failure of any party to require the performance of any term or obligation of this Agreement, or the waiver by any party of any breach of this Agreement, shall not prevent any subsequent enforcement of such term or obligation or be
deemed a waiver of any subsequent breach. 
 16.    Notices. Any notices, requests, demands and other
communications provided for by this Agreement shall be sufficient if in writing and delivered in person or sent by a nationally recognized overnight courier service or by registered or certified mail, postage prepaid, return receipt requested, to
the Employee at the last address the Employee has filed in writing with the Company or, in the case of the Company, at its main offices, attention of the Board. 

  
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 17.    Amendment. This Agreement may be amended or modified only
by a written instrument signed by the Employee and by a duly authorized representative of the Company. 

18.    Governing Law. This is a Massachusetts contract and shall be construed under and be governed in all respects
by the laws of the Commonwealth of Massachusetts without giving effect to the conflict of laws principles thereof. 

19.    Counterparts. This Agreement may be executed in any number of counterparts, each of which when so executed
and delivered shall be taken to be an original; but such counterparts shall together constitute one and the same document. 

20.    Successor to Company. The Company shall require any successor (whether direct or indirect, by purchase,
merger, consolidation or otherwise) to all or substantially all of the business or assets of the Company expressly to assume and agree to perform this Agreement to the same extent that the Company would be required to perform it if no succession had
taken place. Failure of the Company to obtain an assumption of this Agreement at or prior to the effectiveness of any succession shall be a material breach of this Agreement. 

21.    Gender Neutral. Wherever used herein, a pronoun in the masculine gender shall be considered as including the
feminine gender unless the context clearly indicates otherwise. 
 IN WITNESS WHEREOF, the parties have executed this Agreement effective on
the date and year first above written. 
  

			
	KALEIDO BIOSCIENCES, INC.
		
	By:	 	/s/ Michael Bonney
	Its:	 	Executive Chair

  

	
	EMPLOYEE
	
	/s/ Alison Lawton
	ALISON LAWTON

  
 12

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00291-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00291-of-00352.parquet"}]]