Document:

EX-10.13

 Exhibit 10.13 
  

 
 CONFIDENTIAL OFFER LETTER FOR 

CHRISTOPHER STEVENS 

April 28, 2016 
 Dear Chris, 

We are very pleased to offer you a position with Arsanis, Inc. (“Arsanis” or “Company”) as Chief Medical Officer. As outlined in the
position description, you will be responsible for overseeing the Medical and Clinical Research functions at Arsanis. You will report directly to the Chief Executive Officer. 

This offer contains the following terms: 
 1. Start
Date: Your start date will be June 1, 2016 (the “Start Date”). 
 2. Time Commitment: The time
commitment for this position will be a full-time professional commitment. You will be expected to work a minimum of 40 hours per week. You may be required to work more than 40 hours per week as needed. As a
non-exempt employee, you are not eligible for overtime pay. 
 3. Base Salary: Your
full-time salary will be $380,000.00 annually (the “Full Time Base Salary”), which will be paid bi-monthly, and which shall be subject to deductions for taxes and other withholdings as required by
law or the standard and lawful policies of the Company. 
 4. Sign-On Bonus: After the
Start Date, you will be eligible for a one-time sign-on bonus of $100,000.00 (the “Sign-On Bonus”), which will be paid
in full in your first paycheck, and which shall be subject to deductions for taxes and other withholdings as required by law or the standard and lawful policies of the Company. However, the Company’s payment of the Sign-On Bonus to you is conditioned on your remaining employed with the Company for a period of one (1) year, beginning on the Start Date. If your employment is terminated on or before June 1, 2017, either
by you or the Company, for any reason other than by the Company without Cause (as that term is defined in Section 11(a) below) or by you for Good Reason (as that term is defined in Section 11(c) below), or by termination due to death or
disability (as that term is defined in Section 11(e) below) you agree to repay the Company a prorated share of the Sign-On Bonus based on the proportion of time worked divided by one year, less taxes and
other withholdings deducted from the Sign-On Bonus, within ten (10) days of your termination date. If you leave the Company for reason of the Company without cause or by you for Good Reason, or due to
death or disability before one year of the start date, you will not be required to pay back any portion of the sign-on bonus. 

5. Bonus Potential: At the sole discretion of the Company, you will be eligible to earn an annual bonus of up to 30% of your Base
Salary, which will be dependent upon (i) the completion of milestones and performance evaluations established by the Board and President at the outset of your employment and annually thereafter and (ii) overall Company performance and 

 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 prospects. Any bonus paid to you hereunder will be paid no later than March 15th of the year following the calendar year to which the bonus relates, subject to your continuous employment through the end of the calendar year to which such bonus relates. The foregoing shall be
construed and applied so that any bonus payable to you hereunder qualifies as a “short-term deferral” under Section 409A of the Internal Revenue Code of 1986, as amended (“Section 409A”). 

6. Company Shares and Options: At the sole discretion of the Arsanis Board of Directors, Arsanis expects to grant you an option to
purchase up to 90,000 Common Shares (the “Option”) promptly following the Start Date. Such Option will be issued with a strike price equal to the fair market value per Share on grant date, determined in accordance with applicable equity
compensation requirements under Section 409A by the Arsanis Board of Directors in its sole discretion (the Section 409A valuation as of April 22, 2016 was determined to be $2.68 per share). You acknowledge and agree that the equity
interest in the Company represented by the Option may be diluted at any time by the issuance by the Company of more capital stock or options to investors, directors, employees or consultants, and that the value of the Company’s capital stock
may increase or decrease over time. 
 The purchase and sale of the Shares shall be governed by a Stock Option Agreement which shall contain, among other
things, vesting provisions consistent with this offer letter, and a right of the Company to cancel unvested Options under certain circumstances. Twenty-five percent (25%) of such Shares shall vest on the first anniversary of the Start Date, and the
remainder of the Shares shall vest in 36 equal monthly installments thereafter, subject to your continuing employment with the Company as of each such vesting date. 

Your supervisor will review your compensation annually and may adjust it in his or her sole discretion. 

7. Vacation and Other Time Off: You will receive as vacation, sick leave, and flex time, on an annualized basis, paid time off in
the form of: 
  

	 	•	 	up to eleven (11) “holidays” per calendar year in the form of paid time off, such days to be allocated primarily to those official federal and/or public holidays observed in the U.S. and/or Austria, as
mutually agreed upon between you and Arsanis; 

  

	 	•	 	up to twenty-five (25) days of vacation per calendar year in the form of paid time off (accruing at a rate of 2 1/2 days per month), such days to be allocated at your sole discretion and shall be subject to the
Company’s vacation policy; and 

  

	 	•	 	sick leave in the form of paid time off, as required, subject to the Company’s sick leave policy. 

 In
addition, Arsanis believes in a flexible schedule policy that encourages employees to work hard but allows flexibility around when work is done. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 8. Location: You will be primarily located in the Boston area office located at
890 Winter Street, Suite 230, Waltham, MA 02451, and will play an integral role in establishing Arsanis’ U.S. presence and team in the Boston area. You will be asked to travel occasionally to the Company’s offices in Vienna, Austria, as
mutually agreed upon between you and Company. 
 9. Benefits: Arsanis will arrange to provide health, dental, vision, life, and
disability insurance as required by you and your family. 
 While Arsanis does not have a policy of matching employee contributions at this time, Arsanis
will also arrange for your participation in a nationally recognized 401(k) savings and retirement program no later than June 1, 2016. 
 10.
Travel Reimbursement: Arsanis will reimburse you for all reasonable out-of-pocket expenses incurred in the course of your employment, subject in
certain circumstances to approval. 
 11. Termination of Employment: You or Company may terminate your employment at any time for
any reason, with or without cause, subject to the following provisions: 
 a. Termination for Cause: The Company may terminate your
employment for Cause, as defined below, upon written notice to you setting forth in reasonable detail the nature of the Cause. The following, as determined by the Board in its reasonable judgment, shall constitute “Cause” for
termination: 
 i. the commission of, or indictment or conviction for, any felony or any other crime involving dishonesty to
the material detriment of the Company; 
 ii. participation in any fraud, deliberate and substantial misconduct, breach of
duty of loyalty or breach of fiduciary duty against the Company; 
 iii. intentional and substantial damage to any property
of the Company; 
 iv. failure of performance of your duties hereunder (not attributable to sickness, disability or death)
after reasonable written notice no later than thirty (30) days following the occurrence of the condition and a 30-day opportunity to cure; or 

v. your breach of any material provision of this offer letter, your Invention,
Non-Competition, and Non-Disclosure Agreement, or any other agreement to which you and the Company are both parties after reasonable written notice no later than thirty
(30) days following the occurrence of the condition and a 30-day opportunity to cure, provided, however, that such opportunity to cure shall only apply to any breach susceptible to cure and that any
breach by you of your obligations of confidentiality or non-competition under the Invention, Non-Competition, and Non-Disclosure
Agreement shall be deemed not susceptible to cure. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 Termination of your employment by the Company for Cause will result in no severance pay or benefits. 

b. Termination without Cause: The Company may terminate your employment at any time other than for Cause upon written notice to you.

 c. Termination for Good Reason: You may terminate your employment hereunder for Good Reason, as defined below, by providing written
notice to the Company of the condition giving rise to the Good Reason, specifying in reasonable detail the basis for such claim of Good Reason, no later than thirty (30) days following the occurrence of the condition, by giving the Company
thirty (30) days to remedy the condition and by terminating employment for Good Reason within thirty (30) days thereafter if the Company fails to remedy the condition. The following, if occurring without your consent, shall constitute
“Good Reason” for termination by you: 
 i. a material and adverse diminution of your duties and
responsibilities with the Company, provided that such change is not in connection with a termination of your employment relationship with the Company; 

ii. a material diminution of your then Full-Time Base Salary provided that such change is not in connection with a termination
of your employment relationship with the Company; 
 iii. relocation of your principal place of employment outside a thirty
(30) mile radius from Boston, Massachusetts; or 
 iv. a material breach by the Company of this offer letter. 

d. Termination without Good Reason: You may terminate your employment with the Company other than for Good Reason at any time subject to
your provision of thirty (30) days’ advance written notice to the Company (the “Applicable Notice Period’’). 

e. Termination Due to Death or Disability: Your employment shall automatically terminate in the event of your death during employment.
The Company may terminate your employment, upon notice to you, in the event you become disabled during employment through any illness, accident, injury or condition of either a physical or psychological nature and, as a result, are unable to
continue to perform substantially all of your duties and responsibilities (notwithstanding the provision of any reasonable accommodation) for 180 days (whether or not consecutive) during any period of 365 consecutive calendar days. If any question
shall arise as to whether you are disabled to the extent that you are unable to perform substantially all of your duties and responsibilities for the Company, you shall, at the Company’s request and expense, submit to a medical examination by a
mutually acceptable physician in the Boston area who is Board certified in the area of practice involved in the disability and such determination shall, for the purposes of this offer letter, be conclusive of the issue. If such a question arises and
you fail to submit to the requested medical examination, the Company’s determination of the issue shall be binding on you. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 12. Severance and other Matters Related to Termination: 

(a) Termination by the Company without Cause or by You for Good Reason: Subject to Sections 12(b) and 12(f) below
and Section 409A, in the event that your employment is terminated by the Company without Cause pursuant to Section 11(b) of this offer letter or by you for Good Reason pursuant to
Section 11(c) of this offer letter, in addition to the Accrued Compensation (as defined below), the Company shall provide you with the severance payments and benefits specified below: 

i. the Company shall continue to pay you your Full Time Base Salary, at the rate then in effect and in accordance with the
Company’s standard payroll policy as then in effect, for a period following the date on which your employment with the Company terminates, such period being determined as follows (the “Applicable Severance Period”): 

(1) one (1) month with regard to terminations that are initiated within six (6) months of the Start Date; 

(2) two (2) months with regard to terminations that are initiated after six (6) months but before twelve
(12) months following the Start Date; 
 (3) three (3) months with regard to terminations that are initiated on or
after the twelve (12) month anniversary of the Start Date; and 
 ii. subject to your timely election to continue
participation in the Company’s group health and dental plans under COBRA or Massachusetts law, and only for so long as you are eligible for such coverage through COBRA or Massachusetts law, the Company shall pay you, on a monthly and taxable
basis, an amount equal to the full monthly premium cost of such participation until the conclusion of the Applicable Severance Period, or, if earlier, until the date you become eligible to enroll in such plans of any new employer. 

(a) Termination by the Company without Cause or by You for Good Reason in Connection with a Change of Control: Subject to
Section 409A, in the event that your employment is terminated by the Company without Cause pursuant to Section 11(b) of this offer letter or by you for Good Reason pursuant to 11(c) of this
offer letter, in either case, within twelve (12) months following a Change of Control (as defined below), in addition to the Accrued Compensation (as defined below), in lieu of any payments and benefits provided in Section 12(a) above, the
Company shall provide you the severance payments and benefits specified below: 
 i. the Company shall continue to pay you
your Full Time Base Salary, at the rate then in effect, for the Applicable Severance Period plus an additional one (1) month period (together, the “Change of Control Applicable Severance Period”), in accordance with the Company’s
standard payroll policy as then in effect; 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 ii. subject to your timely election to continue participation in the
Company’s group health and dental plans under COBRA, and only for so long as you are eligible for such coverage through COBRA (or Massachusetts laws), the Company shall pay you, on a monthly and taxable basis, an amount equal to the full
monthly premium cost of such participation until the conclusion of the Change of Control Applicable Severance Period, or, if earlier, until the date you become eligible to enroll in such plans of any new employer; and 

iii. all outstanding and unvested stock options and other equity awards then held by you shall become fully vested and
exercisable and, with respect to any stock options then held by you, those options shall remain exercisable for the period of time set forth in the applicable grant agreement. 

In the event that your employment terminates within three (3) months prior to a Change of Control, the Arsanis Board of Directors will promptly review
the causes and circumstances surrounding your termination and, to the extent that such termination is determined at its sole discretion to have been specifically related to such Change of Control and without Cause or for Good Reason, you shall
receive additional severance payments and benefits pursuant to this Section 12(b). 
 c. Termination by the Company Due to Your
Disability or Death: Subject to Section 409A, in the event your employment with the Company is terminated by the Company due to your disability or is terminated due to your death pursuant to
Section 11(e) of this offer letter, in addition to the Accrued Compensation (as defined below), the Company shall pay you at the same time as the Accrued Compensation is paid a pro rata annual bonus for the year in which such termination of
employment occurs, calculated by multiplying your target annual bonus for such year by a fraction, the numerator of which is the number of days you were employed during such year and the denominator of which is 365 (the “Pro-Rata Bonus”). 
 d. Any Other Termination: In the event your employment with the
Company terminates for any reason other than by the Company without Cause pursuant to Section 11(b) of this offer letter, by you for Good Reason pursuant to Section 11(c) of this offer letter, or by the Company due to your disability or
death pursuant to Section 11(e) of this offer letter, the Company shall pay you the Accrued Compensation. For purposes of this offer letter, “Accrued Compensation” means any base salary earned but not paid through the date of
the termination of employment and an amount equal to the value of any vacation time accrued but unused as of such date. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 e. Parachute Payments: 

i. In the event of the consummation of a change in ownership or control within the meaning of Section 280G (a
“280G Change in Control”) of the Company following the time that the Company has stock readily tradeable on an established securities market (within the meaning of Section 280G and the regulations thereunder), if all or a
portion of the payments and benefits under this offer letter, together with any other payments and benefits provided to you by the Company or its Affiliates (including, without limitation, any accelerated vesting of stock options and other equity
awards) (the “Total Payments”), would constitute an “excess parachute payment” within the meaning of Section 280G (the aggregate of such payments (or portions thereof) being hereinafter referred to as the
“Excess Parachute Payments”), you will be entitled to receive (A) an amount limited so that no portion thereof shall fail to be tax deductible under Section 280G (the “Limited Amount”), or (B) if the
amount otherwise payable hereunder or otherwise (without regard to clause (A)) reduced by all taxes applicable thereto (including, for the avoidance of doubt, the excise tax levied under Section 4999 of the Code (the “Excise
Tax”)) would be greater than the Limited Amount reduced by all taxes applicable thereto, the amount otherwise payable hereunder or otherwise. 

ii. The determination as to whether the Total Payments include Excess Parachute Payments and, if so, the amount of such Excess
Parachute Payments, the amount of any Excise Tax with respect thereto, and the amount of any reduction in Total Payments shall be made at the Company’s expense by the independent public accounting firm most recently serving as the
Company’s outside auditors or such other accounting or benefits consulting group or firm as the Company may designate (the “Accountants”). In the event that any payments under this offer letter or otherwise are required to be
reduced as described in Section 12(e)(i) of this offer letter, the adjustment will be made, first, by reducing the amount of base salary payable pursuant to Section 12(a)(i) or 12(b)(i), as applicable; second, if additional reductions are
necessary, by reducing the payment of the amounts due to you pursuant to Section 12(a)(ii) or 12(b)(ii), as applicable; and third, if additional reductions are still necessary, by eliminating the accelerated vesting of stock option awards and
other equity awards, if any, starting with those awards for which the amount required to be taken into account under Section 280G is the greatest. 

iii. In the event that there has been an underpayment or overpayment under this offer letter or otherwise as determined by the
Accountants, the amount of such underpayment or overpayment shall forthwith be paid to you or refunded to the Company, as the case may be, with interest at the applicable federal rate provided for in Section 7872(f)(2) of the Code. 

f. Release: Any obligation of the Company to provide you severance payments or other benefits (including accelerated vesting of stock
options and other equity awards) or any Pro-Rata Bonus (for the avoidance of doubt, other than Accrued Compensation), is conditioned on your (or your legal representative, if applicable, in the case of a
termination due to your 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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disability) signing a release of claims in the form provided by the Company (the ‘‘Release”) following the termination of your employment within a period of time not to
exceed forty-five (45) days from the date of such termination of employment, and on your (or your legal representative, if applicable) not revoking the Release within the revocation period provided therein following your (or your legal
representative’s, if applicable) execution of the Release, which release shall not apply to (i) claims for indemnification in your capacity as an officer or director of the Company under the Company’s Certificate of Incorporation,
Bylaws, insurance or other written agreements, if any, providing for director or officer indemnification, (ii) rights to receive insurance payments under any policy maintained by the Company, (iii) vested rights as an equity holder or
option holder, (iv) rights to receive retirement and other benefits that are accrued and fully vested at the time of your termination, and (v) any other claims that cannot be released as a matter of law. Except as otherwise provided in
Section 409A, any payments to be made in the form of salary continuation pursuant to the terms of this offer letter shall be payable in accordance with the normal payroll practices of the
Company, with the first such payment (which shall be retroactive to the day immediately following the date of your termination of employment) due and payable as soon as administratively practicable following the date the Release becomes effective,
but not later than the date that is sixty (60) days following the date your employment terminates. Notwithstanding the foregoing, if the date your employment terminates occurs in one taxable year and the date that is sixty (60) days
following such termination date occurs in a second taxable year, to the extent required by Section 409A, such first payment shall not be made prior to the first day of the second taxable year. For the avoidance of doubt, if you (or your legal
representative, if applicable) do not execute a Release within the period specified in this Section 12(f), or if you (or your legal representative, if applicable) revoke the executed Release within the time period permitted by law, you will not
be entitled to any payments or benefits (including the accelerated vesting of stock options or other equity awards) or any Pro-Rata Bonus set forth herein (other than the Accrued Compensation), any stock
options and other equity awards that vested on account of such termination as provided for in this offer letter shall be cancelled with no consideration due to you, and the Company will not have any further obligations to you under this offer letter
or otherwise. You agree to provide the Company prompt notice of your eligibility to participate in the health and, if applicable, dental, plan of any subsequent employer. You further agree to repay any overpayment of health and, if applicable,
dental, benefit premiums made by the Company hereunder. Notwithstanding anything to the contrary herein, in the event that the Company’s payment of the amounts described in Section 12(a)(ii) or (b)(ii), as applicable, would subject the
Company to any tax or penalty under the Patient Protection and Affordable Care Act (as amended from time to time, the “ACA”) or Section 105(h) of the Internal Revenue Code of 1986, as amended (“Section 105(h)”), or
applicable regulations or guidance issued under the ACA or Section 105(h), you and the Company agree to work together in good faith to restructure such benefit. 

g. Survival, Conditions to Severance: Provisions of this offer letter shall survive any termination if so provided in this offer letter
or if necessary or desirable to accomplish the purposes of other surviving provisions of the offer letter and the Invention, Non-Competition and Non-Disclosure
Agreement. The obligation of the Company to make severance payments to you or on your behalf is expressly conditioned upon (i) your full performance, and continued 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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performance during any applicable severance periods, of your material obligations under this offer letter, the Invention, Non-Competition and Non-Disclosure Agreement, and any subsequent agreement between you and the Company relating to, without limitation, confidentiality, non-competition, proprietary information
or the like, and (ii) your (or your legal representative’s, if applicable, in the case of a termination due to your disability) execution and non-revocation of the Release as set forth above. 

13. Definitions: For purposes of this offer letter, the following definitions apply: 

a. “Change of Control” means the first to occur of any of the following: (i) a merger or consolidation in which
(A) the Company is a constituent party, or (B) a subsidiary of the Company is a constituent party and the Company issues shares of its capital stock pursuant to such merger or consolidation, except in the case of either clause (A) or
(B) any such merger or consolidation involving the Company or a subsidiary of the Company in which the beneficial owners of the shares of capital stock of the Company outstanding immediately prior to such merger or consolidation continue
beneficially to own, immediately following such merger or consolidation, at least a majority by voting power of the capital stock of (x) the surviving or resulting corporation or (y) if the surviving or resulting corporation is a wholly
owned subsidiary of another corporation immediately following such merger or consolidation, the parent corporation of such surviving or resulting corporation; (ii) the sale, lease, transfer, exclusive license or other disposition, in a single
transaction or series of related transactions, by the Company or a Company subsidiary of all or substantially all the assets of the Company and the Company subsidiaries taken as a whole (except in connection with a merger or consolidation not
constituting a Change of Control under clause (i) or where such sale, lease, transfer, exclusive license or other disposition is to a wholly owned Company subsidiary); or (iii) the sale or transfer, in a single transaction or series of
related transactions, by the stockholders of the Company of more than 50% by voting power of the then-outstanding capital stock of the Company to any Person or entity or group of affiliated Persons or entities. 

b. “Code” means the Internal Revenue Code of 1986, as amended. 

c. “Person” means an individual, a corporation, an association, a partnership, an estate, a trust and any other entity
or organization, other than the Company. 
 d. “Section 280G” means Section 280G of the Code,
together with the regulations thereunder. 
 14. Section 409A. 

a. You and the Company agree that this offer letter shall be interpreted to comply with or be exempt from Section 409A, and the
regulations and guidance promulgated thereunder to the extent applicable, and all provisions of this offer letter shall be construed in a manner consistent with the requirements for avoiding taxes or penalties under Section 409A. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

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 b. A termination of employment shall not be deemed to have occurred for purposes of
any provision of this offer letter providing for the payment of any amounts or benefits considered “nonqualified deferred compensation” under Section 409A upon or following a termination of employment unless such termination is also a
“separation from service” within the meaning of Section 409A (after giving effect to the presumptions contained therein) and, for purposes of any such provision of this offer letter, references to a “termination,”
“termination of employment” or like terms shall mean “separation from service.” If you are deemed on the date of termination to be a “specified employee” within the meaning of that term under Section 409A(a)(2)(B),
then with regard to any payment or the provision of any benefit that is considered nonqualified deferred compensation under Section 409A payable on account of a “separation from service,” such payment or benefit shall be made or
provided at the date which is the earlier of (a) the expiration of the six-month period measured from the date of such “separation from service”, and (b) the date of your death (the
“Delay Period”). Upon the expiration of the Delay Period, all payments and benefits delayed pursuant to this Section 14(b) (whether they would have otherwise been payable in a single sum or in installments in the absence of
such delay) shall be paid or reimbursed on the first business day following the expiration of the Delay Period to you in a lump sum, and any remaining payments and benefits due under this offer letter shall be paid or provided in accordance with the
normal payment dates specified for them herein. 
 c. With regard to any provision herein that provides for payment or reimbursement
of costs and expenses or in-kind benefits, except as permitted by Section 409A, (a) the right to payment, reimbursement or in-kind benefits shall not be
subject to liquidation or exchange for another benefit; (b) the amount of expenses eligible for payment or reimbursement, or in-kind benefits, provided during any taxable year shall not affect the
expenses eligible for payment or reimbursement, or in-kind benefits, to be provided in any other taxable year; and (c) such payments shall be made on or before the last day of your taxable year following
the taxable year in which the expense occurred. 
 d. For purposes of Section 409A, your right to receive any installment
payments pursuant to this offer letter shall be treated as a right to receive a series of separate and distinct payments. 
 e. In no
event shall the Company have any liability relating to the failure or alleged failure of any payment or benefit under this offer letter to comply with, or be exempt from, the requirements of Section 409A. 

15. At-Will Status: As is true for all Company employees, your employment with Arsanis will
be “at-will.” This means that your employment is for no specified period of time, and may be terminated at any time by either you or the Company, with or without cause, subject the provisions of this
offer letter. This letter is not meant to be a contract of employment for any specific duration. 

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

10 

 

 
  

 16. Conditions/Required Documentation: This offer of employment is conditioned on
the completion of a satisfactory background check. Further, as a condition of employment, the Company will require you to sign an Invention, Non-Competition, and
Non-Disclosure Agreement, a form of which has been provided. You will also be required to acknowledge in writing that you have read the Company employee handbook, and have agreed to follow its rules and
regulations. To comply with government-mandated confirmation of employment eligibility, you also will be required to provide proof of your employment eligibility in the form of completed I-9 documentation and
the provision of related identification documents. 
 17. Miscellaneous: Your rights and obligations under this letter shall be
neither assignable nor delegable by you, except to the extent that any rights to compensation hereunder may be assigned to your estate or legal representative in the event of your death or disability. This offer letter shall be binding upon and
inure to the benefit of you and the Company and your and its respective permitted successors and assigns. This offer letter shall be interpreted under the laws of the Commonwealth of Massachusetts. 

If you would like to accept this offer, please sign and return this letter by the end of the day on May 6, 2016. 

We look forward to welcoming you as part of the Arsanis team. 

Sincerely, 
  

	
	 /s/ Rene Russo

	Rene Russo
	
	Chief Executive Officer
	
	AGREED TO:
	
	 /s/ Christopher Stevens

	Christopher Stevens
	
	 May 27, 2016

	Date

  
 Arsanis, Inc. | 890
Winter Street Suite 230 • Waltham, MA • 02451 | Phone: (781) 819-5153 | 
 www.arsanis.com 

11EX-10.14

 Exhibit 10.14 

INDEMNIFICATION AGREEMENT 

THIS AGREEMENT (the “Agreement”) is made and entered into as of
[                    ] between Arsanis, Inc., a Delaware corporation (the “Company,” which term shall include where appropriate, any Entity
(as hereinafter defined)), and [                    ] (“Indemnitee”). 

WHEREAS, it is essential to the Company that it be able to retain and attract as directors the most capable persons available; 

WHEREAS, increased corporate litigation has subjected directors to litigation risks and expenses, and the limitations on the availability of
directors’ and officers’ liability insurance has made it increasingly difficult for the Company to attract and retain such persons; 

WHEREAS, the Company desires to provide Indemnitee with specific contractual assurance of Indemnitee’s rights to indemnification against
litigation risks and expenses (regardless, among other things, of any amendment to or revocation of the Company’s Certificate of Incorporation or By-Laws, each as amended from time to time (the
“Charter Documents”), any change in the ownership of the Company or the composition of its Board of Directors) which indemnification is intended to be greater than that which is afforded by the Charter Documents; 

WHEREAS, in accordance with the authorization as provided by applicable law and the provisions of the certificate of incorporation and by-laws, the Company shall maintain a policy or policies of directors’ and officers’ liability insurance (“D & 0 Insurance”), covering certain liabilities which may be incurred by its
directors in the performance of their obligations to the Company; and 
 WHEREAS, in order to induce Indemnitee to serve as a director of
the Company, the Company has determined and agreed to enter into this Agreement with Indemnitee. 
 WHEREAS, Indemnitee has certain rights
to indemnification and/or insurance provided by [                    ] and/or certain of its affiliates (the “Fund Indemnitors”), which
Indemnitee and the Fund Indemnitors intend to be secondary to the primary obligation of the Company to indemnify Indemnitee as provided herein, with the Company’s acknowledgement and agreement to the foregoing being a material condition to
Indemnitee’s willingness to serve on the Board. 
 NOW, THEREFORE, in consideration of Indemnitee’s service as a director, the
parties hereto agree as follows: 
 I. Definitions. For purposes of this Agreement: 

(a) “Corporate Status” describes the status of a person who is serving or has served (i) as a director of the Company, including
as a member of any committee thereof, (ii) in any capacity with respect to any employee benefit plan of the Company, or (iii) as a director, partner, trustee, officer, employee, or agent of any other Entity (as defined below) at the
request of the Company. For purposes of subsection (iii) of this Section 1(a), a director of the Company who is serving or has served as a director, partner, trustee, officer, employee or agent of a Subsidiary (as defined below) shall be deemed
to be serving at the request of the Company. 

  
 1 

 (b) “Disinterested Director” means a director of the Company who is not and was not a
party to the Proceeding in respect of which indemnification is sought by Indemnitee. 
 (c) “Entity” shall mean any corporation,
partnership, limited liability company, joint venture, trust, foundation, association, organization or other legal entity. 
 (d)
“Expenses” shall mean all reasonable fees, costs and expenses actually incurred in connection with any Proceeding (as defined below), including, without limitation, reasonable attorneys’ fees, disbursements and retainers, reasonable
fees and disbursements of expert witnesses, private investigators and professional advisors (including, without limitation, accountants and investment bankers), court costs, transcript costs, fees of experts, travel expenses, duplicating, printing
and binding costs, telephone and fax transmission charges, postage, delivery services, secretarial services and other reasonable disbursements and expenses. 

(e) “Independent Counsel” means a law firm, or a member of a law firm, that is experienced in matters of corporation law and neither
presently is, nor in the past five years has been, retained to represent: (i) the Company or Indemnitee in any matter material to either such party (other than with respect to matters concerning the Indemnitee under this Agreement, or of other
indemnitees under similar indemnification agreements), or (ii) any other party to the Proceeding giving rise to a claim for indemnification hereunder. Notwithstanding the foregoing, the term “Independent Counsel” shall not include any
person who, under the applicable standards of professional conduct then prevailing, would have a conflict of interest in representing either the Company or Indemnitee in an action to determine Indemnitee’s rights under this Agreement. The
Company agrees to pay the reasonable fees of the Independent Counsel referred to above and to fully indemnify such counsel against any and all Expenses and Liabilities (as defined below) arising out of or relating to this Agreement or its engagement
pursuant hereto. 
 (1) “Liabilities” shall mean judgments, damages, liabilities, losses, penalties, excise taxes, fines and
amounts paid in settlement. 
 (g) “Proceeding” shall mean any threatened, pending or completed claim, action, suit, arbitration,
alternate dispute resolution process, investigation, administrative hearing, appeal, or any other proceeding, whether civil, criminal, administrative, arbitrative or investigative, whether formal or informal, including a proceeding initiated by
Indemnitee pursuant to Section 10 of this Agreement to enforce Indemnitee’s rights hereunder, and shall include a Proceeding pending on or before the date of this Agreement. 

(h) “Subsidiary” shall mean any corporation, partnership, limited liability company, joint venture, trust or other Entity of which
the Company owns (either directly or through or together with another Subsidiary of the Company) either (i) a general partner, managing member or other similar interest or (ii) (A) more than 50% of the voting power of the voting capital
equity interests of such corporation, partnership, limited liability company, joint venture or other Entity, or (B) more than 50% of the outstanding voting capital stock or other voting equity interests of such corporation, partnership, limited
liability company, joint venture or other Entity. 

  
 2 

 2. Agreement to Indemnify. 

(a) Proceedings Other Than Proceedings by or in the Right of the Company. Indemnitee shall be entitled to the rights of indemnification
provided in this Section 2(a) if, by reason of Indemnitee’ s Corporate Status, Indemnitee is, or is threatened to be made, a party to or participant in any Proceeding other than a Proceeding by or in the right of the Company or a
Proceeding instituted by Indemnitee pursuant to Section 9 of this Agreement to enforce Indemnitee’s rights under this Agreement. Pursuant to this Section 2(a), Indemnitee shall be indemnified by the Company against all Expenses and
Liabilities incurred or paid by Indemnitee in connection with such Proceeding, if Indemnitee acted in good faith and in a manner Indemnitee reasonably believed to be in or not opposed to the best interests of the Company and, with respect to any
criminal Proceeding, had no reasonable cause to believe Indemnitee’ s conduct was unlawful. 
 (b) Proceedings by or in the Right of
the Company. Indemnitee shall be entitled to the rights of indemnification provided in this Section 2(b) if, by reason of Indemnitee’s Corporate Status, Indemnitee is, or is threatened to be made, a party to or participant in any
Proceeding brought by or in the right of the Company. Pursuant to this Section 2(b), Indemnitee shall be indemnified by the Company against all Expenses incurred or paid by Indemnitee in connection with such Proceeding if Indemnitee acted in
good faith and in a manner Indemnitee reasonably believed to be in or not opposed to the best interests of the Company; provided, however, that, if applicable law so provides, no indemnification against such Expenses shall be made in respect
of any claim, issue or matter in such Proceeding as to which Indemnitee shall have been adjudged to be liable to the Company unless and to the extent that the Court of Chancery of the State of Delaware or other court of competent jurisdiction shall
determine that such indemnification may be made. 
 3. Indemnification for Expenses of a Party Who is Wholly or Partly Successful.
Notwithstanding any other provision of this Agreement, to the extent that Indemnitee is, by reason of Indemnitee’s Corporate Status, a party to and is successful, on the merits or otherwise, in any Proceeding, Indemnitee shall be indemnified to
the maximum extent permitted by applicable law against all Expenses and Liabilities incurred or paid by Indemnitee in connection therewith. If Indemnitee is not wholly successful in such Proceeding but is successful, on the merits or otherwise, as
to one or more but less than all claims, issues or matters in such Proceeding, the Company shall indemnify Indemnitee against all Expenses and Liabilities incurred or paid by Indemnitee in connection with each successfully resolved claim, issue or
matter. For purposes of this Section and without limitation, the termination of any claim, issue or matter in such a Proceeding by dismissal, with or without prejudice, shall be deemed to be a successful result as to such claim, issue or matter.

 4. Additional Indemnity. In addition to, and without regard to any limitations on, the indemnification provided for in
Section 2, the Company shall and hereby does indemnify and hold harmless Indemnitee against all Expenses and Liabilities incurred or paid by Indemnitee or on Indemnitee’s behalf if, by reason of Indemnitee’s Corporate Status,
Indemnitee is, or is 

  
 3 

 threatened to be made, a party to or participant in any Proceeding (including a Proceeding by or in the right of
the Company), including, without limitation, all liability arising out of the negligence or active or passive wrongdoing of Indemnitee. The only limitation that shall exist upon the Company’s obligations pursuant to this Agreement shall be that
the Company shall not be obligated to make any payment to Indemnitee that is finally determined (under the procedures, and subject to the presumptions, set forth in Section 8 hereof) to be unlawful under applicable law. 

5. Contribution in the Event of Joint Liability. 

(a) Whether or not the indemnification provided in Sections 2 or 4 hereof is available, in respect of any threatened, pending or completed
action, suit or proceeding in which the Company is jointly liable with Indemnitee (or would be if joined in such action, suit or proceeding), the Company shall pay, in the first instance, the entire amount of any judgment or settlement of such
action, suit or proceeding without requiring Indemnitee to contribute to such payment and the Company hereby waives and relinquishes any right of contribution it may have against Indemnitee. The Company shall not enter into any settlement of any
action, suit or proceeding in which the Company is jointly liable with Indemnitee (or would be if joined in such action, suit or proceeding) unless such settlement provides for a full and final release of all claims asserted against Indemnitee. 

(b) Without diminishing or impairing the obligations of the Company set forth in the preceding subparagraph, if, for any reason, Indemnitee
shall elect or be required to pay all or any portion of any judgment or settlement in any threatened, pending or completed action, suit or proceeding in which the Company is jointly liable with Indemnitee (or would be if joined in such action, suit
or proceeding), the Company shall contribute to the amount of Expenses and Liabilities incurred and paid or payable by Indemnitee in proportion to the relative benefits received by the Company and all officers, directors or employees of the Company
other than Indemnitee who are jointly liable with Indemnitee (or would be if joined in such action, suit or proceeding), on the one hand, and Indemnitee, on the other hand, from the transaction from which such action, suit or proceeding arose;
provided, however, that the proportion determined on the basis of relative benefit may, to the extent necessary to conform to law, be further adjusted by reference to the relative fault of the Company and all officers, directors or employees
of the Company other than Indemnitee who are jointly liable with Indemnitee (or would be if joined in such action, suit or proceeding), on the one hand, and Indemnitee, on the other hand, in connection with the events that resulted in such Expenses
or Liabilities, as well as any other equitable considerations which the law may require to be considered. The relative fault of the Company and all officers, directors or employees of the Company other than Indemnitee who are jointly liable with
Indemnitee (or would be if joined in such action, suit or proceeding), on the one hand, and Indemnitee, on the other hand, shall be determined by reference to, among other things, the degree to which their actions were motivated by intent to gain
personal profit or advantage, the degree to which their liability is primary or secondary, and the degree to which their conduct is active or passive. 

(c) The Company hereby agrees to fully indemnify and hold Indemnitee harmless from any claims of contribution which may be brought by officers,
directors or employees of the Company other than Indemnitee who may be jointly liable with Indemnitee. 

  
 4 

 6. Indemnification for Expenses of a Witness or in Response to a Subpoena. Notwithstanding
any other provision of this Agreement, to the extent that Indemnitee, is by reason of Indemnitee’s Corporate Status, a witness in any Proceeding to which Indemnitee is not a party, or receives a subpoena in any Proceeding to which Indemnitee is
not a party, Indemnitee shall be indemnified against all Expenses paid or incurred by Indemnitee in connection therewith and in the manner set forth in this Agreement. 

7. Advancement of Expenses. Notwithstanding any other provision of this Agreement, the Company shall advance all Expenses incurred by or
on behalf of Indemnitee in connection with any Proceeding by reason of Indemnitee’s Corporate Status within thirty (30) days after the receipt by the Company of a statement or statements from Indemnitee requesting such advance or advances
from time to time, whether prior to or after final disposition of such Proceeding. Such statement or statements shall reasonably evidence the Expenses incurred by Indemnitee and shall include or be preceded or accompanied by an undertaking by or on
behalf of Indemnitee to repay any Expenses advanced if it shall ultimately be determined by a final, non-appealable order of the Court of Chancery of the State of Delaware or other court of competent
jurisdiction that Indemnitee is not entitled to be indemnified against such Expenses. Any advances and undertakings to repay pursuant to this Section 7 shall be unsecured and interest free and made without regard to Indemnitee’s financial
ability to repay such Expenses. 
 8. Procedures and Presumptions for Determination of Entitlement to Indemnification. It is the
intent of this Agreement to secure for Indemnitee rights of indemnity that are at least as favorable as may be permitted under applicable law and public policy of the State of Delaware. Accordingly, the parties agree that the following procedures
and presumptions shall apply in the event of any question as to whether Indemnitee is entitled to indemnification under this Agreement: 

(a) To obtain indemnification (including, but not limited to, the advancement of Expenses and contribution by the Company) under this
Agreement, Indemnitee shall submit to the Company a written request, including therein or therewith such documentation and information as is reasonably available to Indemnitee and is reasonably necessary to determine whether and to what extent
Indemnitee is entitled to indemnification. 
 (b) Upon written request by Indemnitee for indemnification pursuant to the first sentence of
Section 8(a) hereof, a determination, if required by applicable law, with respect to Indemnitee’s entitlement thereto shall be made in the specific case by one of the following three methods, which shall be at the sole election of
Indemnitee: (J) by a majority vote of the Disinterested Directors, even though less than a quorum, or (2) by Independent Counsel in a written opinion, or (3) by the stockholders of the Company. 

(c) If the determination of entitlement to indemnification is to be made by Independent Counsel pursuant to Section 8(b) hereof, the
Independent Counsel shall be selected as provided in this Section 8(c). The Independent Counsel shall be selected by Indemnitee (unless Indemnitee shall request that such selection be made by the Board of Directors). Indemnitee or the Company,
as the case may be, may, within 10 days after such written notice of selection shall have been given, deliver to the Company or to Indemnitee, as the case may be, a written objection to such selection; provided, however, that such objection
may be asserted only 

  
 5 

 on the ground that the Independent Counsel so selected does not meet the requirements of “Independent
Counsel” as defined in Section I of this Agreement, and the objection shall set forth with particularity the factual basis of such assertion. Absent a proper and timely objection, the person so selected shall act as Independent Counsel. If a
written objection is made and substantiated, the Independent Counsel selected may not serve as Independent Counsel unless and until such objection is withdrawn or a court has determined that such objection is without merit. If, within 20 days after
submission by Indemnitee of a written request for indemnification pursuant to Section 8(a) hereof, no Independent Counsel shall have been selected and not objected to, either the Company or Indemnitee may petition the Court of Chancery of the
State of Delaware or other court of competent jurisdiction for resolution of any objection which shall have been made by the Company or Indemnitee to the other’s selection of Independent Counsel and/or for the appointment as Independent Counsel
of a person selected by the court or by such other person as the court shall designate, and the person with respect to whom all objections are so resolved or the person so appointed shall act as Independent Counsel under Section 8(b) hereof.
The Company shall pay any and all reasonable fees and expenses of Independent Counsel incurred by such Independent Counsel in connection with acting pursuant to Section 8(b) hereof, and the Company shall pay all reasonable fees and expenses
incident to the procedures of this Section 8(c), regardless of the manner in which such Independent Counsel was selected or appointed. 

(d) In making a determination with respect to entitlement to indemnification hereunder, the person or persons or entity making such
determination shall presume that Indemnitee is entitled to indemnification under this Agreement if Indemnitee has submitted a request for indemnification in accordance with Section 8(a) of this Agreement. Anyone seeking to overcome this
presumption shall have the burden of proof and the burden of persuasion, by clear and convincing evidence. 
 (e) Indemnitee shall be deemed
to have acted in good faith for purposes of indemnification under this Agreement if Indemnitee’s actions are based on the records or books of account of the Company, including financial statements, or on information supplied to Indemnitee by
the directors, officers, agents or employees of the Company in the course of their duties, or on the advice of legal counsel for the Company or on information or records given or reports made to the Company by an independent certified public
accountant or by an appraiser or other expert selected by the Company. In addition, the knowledge and/or actions, or failure to act, of any director, officer, agent or employee of the Company shall not be imputed to Indemnitee for purposes of
determining the right to indemnification under this Agreement. Whether or not the foregoing provisions of this Section 8(e) are satisfied, it shall in any event be presumed that Indemnitee has at all times acted in good faith and in a manner
Indemnitee reasonably believed to be in or not opposed to the best interests of the Company. Anyone seeking to overcome this presumption shall have the burden of proof and the burden of persuasion, by clear and convincing evidence. 

(f) If the person, persons or entity empowered or selected under Section 8 to determine whether Indemnitee is entitled to indemnification
shall not have made a determination within forty-five (45) days after receipt by the Company of the request therefor, the requisite determination of entitlement to indemnification shall be deemed to have been made and Indemnitee shall be
entitled to such indemnification, absent (i) a misstatement by Indemnitee of 

  
 6 

 a material fact, or an omission of a material fact necessary to make Indemnitee’ s statement not materially
misleading, in connection with the request for indemnification, or (ii) a prohibition of such indemnification under applicable law; provided, however, that such forty-five day period may be extended for a reasonable time, not to exceed
an additional fifteen (15) days, if the person, persons or entity making the determination with respect to entitlement to indemnification in good faith requires such additional time for the obtaining or evaluating documentation and/or
information relating thereto; and provided, further, that the foregoing provisions of this Section 8(f) shall not apply if the determination of entitlement to indemnification is to be made by the stockholders of the Company pursuant to
Section 8(b) of this Agreement and if (A) within fifteen (15) days after receipt by the Company of the request for such determination the Board of Directors or the Disinterested Directors, if appropriate, resolve to submit such
determination to the stockholders for their consideration at an annual meeting thereof to be held within seventy five (75) days after such receipt and such determination is made thereat, or (B) a special meeting of stockholders is called
within fifteen (15) days after such receipt for the purpose of making such determination, such meeting is held for such purpose within sixty (60) days after having been so called and such determination is made thereat. 

(g) Indemnitee shall cooperate with the person, persons or entity making such determination with respect to Indemnitee’s entitlement to
indemnification, including providing to such person, persons or entity upon reasonable advance request any documentation or information which is not privileged or otherwise protected from disclosure and which is reasonably available to Indemnitee
and reasonably necessary to such determination. Any Independent Counsel, member of the Board of Directors, or stockholder of the Company shall act reasonably and in good faith in making a determination under the Agreement of the Indemnitee’s
entitlement to indemnification. Any costs or expenses (including attorneys’ fees and disbursements) incurred by Indemnitee in so cooperating with the person, persons or entity making such determination shall be borne by the Company
(irrespective of the determination as to Indemnitee’s entitlement to indemnification) and the Company hereby indemnifies and agrees to hold Indemnitee harmless therefrom. 

(h) The Company acknowledges that a settlement or other disposition short of final judgment may be successful if it permits a party to avoid
expense, delay, distraction, disruption and uncertainty. In the event that any action, claim or proceeding to which Indemnitee is a party is resolved in any manner other than by adverse judgment against Indemnitee (including, without limitation,
settlement of such action, claim or proceeding with or without payment of money or other consideration) it shall be presumed that Indemnitee has been successful on the merits or otherwise in such action, suit or proceeding. Anyone seeking to
overcome this presumption shall have the burden of proof and the burden of persuasion, by clear and convincing evidence. 
 9. Remedies of
Indemnitee. 
 (a) In the event that (i) a determination is made pursuant to Section 8 of this Agreement that Indemnitee is not
entitled to indemnification under this Agreement, (ii) advancement of Expenses is not timely made pursuant to Section 7 of this Agreement, (iii) no determination of entitlement to indemnification shall have been timely made pursuant to
Section 8(b) of this Agreement after receipt by the Company of the request for indemnification, or 

  
 7 

 (iv) payment of indemnification is not made within thirty (30) days after a determination has been made that
Indemnitee is entitled to indemnification or such determination is deemed to have been made pursuant to Section 8 of this Agreement, Indemnitee shall be entitled to an adjudication in the Chancery Court of the State of Delaware, or in any other
court of competent jurisdiction, of Indemnitee’s entitlement to such indemnification. The Company shall not oppose Indemnitee’s right to seek any such adjudication. 

(b) In the event that a determination shall have been made pursuant to Section S(b) of this Agreement that Indemnitee is not entitled to
indemnification, any judicial proceeding commenced pursuant to this Section 9 shall be conducted in all respects as a de nova trial, on the merits and Indemnitee shall not be prejudiced by reason of that adverse determination under
Section S(b). 
 (c) If a determination shall have been made pursuant to Section S(b) of this Agreement that Indemnitee is entitled to
indemnification, the Company shall be bound by such determination in any judicial proceeding commenced pursuant to this Section 9, absent a prohibition of such indemnification under applicable law. 

(d) In the event that Indemnitee, pursuant to this Section 9, seeks a judicial adjudication of Indemnitee’s rights under, or to
recover damages for breach of, this Agreement, or to recover under any directors’ and officers’ liability insurance policies maintained by the Company, the Company shall pay on Indemnitee’s behalf, in advance, any and all Expenses
paid or incurred by him in such judicial adjudication, regardless of whether Indemnitee ultimately is determined to be entitled to such indemnification, advancement of expenses or insurance recovery. The Company shall, within thirty (30) days
after receipt by the Company of a written request therefor from Indemnitee, advance such Expenses to Indemnitee pursuant to comparable procedures as those set forth in Section 7 with respect to advancement of Expenses therein. 

(e) The Company shall be precluded from asserting in any judicial proceeding commenced pursuant to this Section 9 that the procedures and
presumptions of this Agreement are not valid, binding and enforceable and shall stipulate in any such court that the Company is bound by all the provisions of this Agreement. 

10. Non-Exclusivity; Survival of Rights; Insurance; Subrogation, Primacy of Indemnification.

 (a) The rights of indemnification as provided by this Agreement shall not be deemed exclusive of any other rights to which Indemnitee may
at any time be entitled under applicable law, the Charter Documents, a vote of stockholders or a resolution of directors, or otherwise. The Company shall not adopt any amendment to the Charter Documents the effect of which would be to deny, diminish
or encumber the Indemnitee’ s rights to identification pursuant to this Agreement, the Charter Documents or applicable law prior to such amendment, alteration or repeal. To the extent that a change in applicable law, whether by statute or
judicial decision, permits greater indemnification than would be afforded currently under the Charter Documents and this Agreement, Indemnitee shall enjoy by this Agreement the greater benefits so afforded by such change. No right or remedy herein
conferred is intended to be exclusive of any other right or remedy, and every other right and remedy shall be cumulative and in addition to every 

  
 8 

 other right and remedy given hereunder or now or hereafter existing at law or in equity or otherwise. The
assertion or employment of any right or remedy hereunder, or otherwise, shall not prevent the concurrent assertion or employment of any other right or remedy. 

(b) The Indemnitee shall be covered by the D & 0 Insurance and any other insurance policy or policies providing liability insurance
for directors, officers, employees, or agents or fiduciaries of the Company or of any other corporation, partnership, joint venture, trust, employee benefit plan or other enterprise which such person serves at the request of the Company, and
Indemnitee shall be covered by such policy or policies in accordance with its or their terms to the maximum extent of the coverage available for any such director, officer, employee or agent under such policy or policies. 

(c) In the event of any payment under this Agreement, the Company shall be subrogated to the extent of such payment to all of the rights of
recovery of Indemnitee, who shall execute all papers required and take all action necessary to secure such rights, including execution of such documents as are necessary to enable the Company to bring suit to enforce such rights. 

(d) The Company shall not be liable under this Agreement to make any payment of amounts otherwise indemnifiable hereunder if and to the extent
that Indemnitee has otherwise actually received such payment under any insurance policy, contract, agreement or otherwise. 
 (e) The Company
hereby acknowledges that Indemnitee has certain rights to indemnification, advancement of expenses and/or insurance provided by the Fund Indemnitors. The Company hereby agrees (i) that it is the indemnitor of first resort (i.e., its obligations
to Indemnitee are primary and any obligation of the Fund Indemnitors to advance expenses or to provide indemnification for the same expenses or liabilities incurred by Indemnitee are secondary), (ii) that it shall be required to advance the full
amount of expenses incurred by Indemnitee and shall be liable for the full amount of all Expenses, judgments, penalties, fines and amounts paid in settlement to the extent legally permitted and as required by the terms of this Agreement and the
Certificate of Incorporation or Bylaws of the Company (or any other agreement between the Company and Indemnitee), without regard to any rights Indemnitee may have against the Fund Indemnitors, and, (iii) that it irrevocably waives,
relinquishes and releases the Fund Indemnitors from any and all claims against the Fund Indemnitors for contribution, subrogation or any other recovery of any kind in respect thereof. The Company further agrees that no advancement or payment by the
Fund Indemnitors on behalf of Indemnitee with respect to any claim for which Indemnitee has sought indemnification from the Company shall affect the foregoing and the Fund Indemnitors shall have a right of contribution and/or be subrogated to the
extent of such advancement or payment to all of the rights of recovery of Indemnitee against the Company. The Company and Indemnitee agree that the Fund Indemnitors are express third party beneficiaries of the terms of this Section lO(e). 

11. Exception to Right of Indemnification. Notwithstanding any other provision of this Agreement, Indemnitee shall not be entitled to
indemnification under this Agreement with respect to any Proceeding brought by Indemnitee, or any claim therein, unless (a) the bringing of such Proceeding or making of such claim shall have been approved by the Board of Directors of the
Company or (b) such Proceeding is being brought by the Indemnitee to assert, interpret or enforce Indemnitee’s rights under this Agreement. 

  
 9 

 12. Duration of Agreement. All agreements and obligations of the Company contained herein
shall continue during the period Indemnitee is a director of the Company (or is or was serving at the request of the Company as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise) and
shall continue thereafter so long as Indemnitee shall be subject to any current or future Proceeding (or any proceeding commenced under Section 9) by reason of Indemnitee’s Corporate Status, whether or not Indemnitee is acting or serving
in any such capacity at the time any liability or expense is incurred for which indemnification can be provided under this Agreement. This Agreement shall be binding upon and inure to the benefit of and be enforceable by the parties hereto and their
respective successors (including any direct or indirect successor by purchase, merger, consolidation or otherwise to all or substantially all of the business or assets of the Company), assigns, spouses, heirs, executors and personal and legal
representatives. This Agreement shall continue in effect regardless of whether Indemnitee continues to serve as an officer or director of the Company or any other Entity at the Company’s request. 

13. Security. To the extent requested by the Indemnitee and approved by the Board of Directors of the Company, the Company may at any
time and from time to time provide security to the Indemnitee for the Company’s obligations hereunder through an irrevocable bank line of credit, funded trust or other collateral. Any such security, once provided to the Indemnitee, may not be
revoked or released without the prior written consent of the Indemnitee. 
 14. Enforcement. 

(a) The Company expressly confirms and agrees that it has entered into this Agreement and assumed the obligations imposed on it hereby in order
to induce Indemnitee to serve as a director of the Company, and the Company acknowledges that Indemnitee is relying upon this Agreement in serving as a director of the Company. 

(b) This Agreement constitutes the entire agreement between the parties hereto with respect to the subject matter hereof and supersedes all
prior agreements and understandings, oral, written and implied, between the parties hereto with respect to the subject matter hereof. 
 15.
Fees and Expenses: During the term of the Indemnitee’s service as a director, the Company shall promptly reimburse the Indemnitee for all reasonable
out-of-pocket expenses incurred by him in connection with Indemnitee’s service as a director or member of any board committee or otherwise in connection with the
Company’s conduct of business. 
 16. Severability. If any provision or provisions of this Agreement shall be held by a court of
competent jurisdiction to be invalid, void, illegal or otherwise unenforceable for any reason whatsoever: (a) the validity, legality and enforceability of the remaining provisions of this Agreement (including without limitation, each portion of
any section of this Agreement containing any such provision held to be invalid, illegal or unenforceable, that is not itself invalid, illegal or unenforceable) shall not in any way be affected or impaired thereby and shall

  
 10 

 remain enforceable to the fullest extent permitted by applicable law; and (b) to the fullest extent
possible, the provisions of this Agreement (including, without limitation, each portion of any section of this Agreement containing any such provision held to be invalid, illegal or unenforceable, that is not itself invalid, illegal or
unenforceable) shall be construed so as to give effect to the intent manifested thereby. 
 17. Modification and Waiver. Except as
provided by Section 1O(a) with respect to changes in applicable law that broaden the rights of Indemnitee to be indemnified by the Company, no supplement, modification, termination or amendment of this Agreement shall be binding unless executed
in writing by both of the parties hereto. No waiver of any of the provisions of this Agreement shall be deemed or shall constitute a waiver of any other provisions hereof (whether or not similar) nor shall such waiver constitute a continuing waiver.

 18. Notice By Indemnitee. Indemnitee agrees promptly to notify the Company in writing upon being served with any summons, citation,
subpoena, complaint, indictment, information or other document relating to any Proceeding or matter which may be subject to indemnification covered hereunder. The failure to so notify the Company shall not relieve the Company of any obligation which
it may have to the Indemnitee under this Agreement or otherwise unless and only to the extent that such failure or delay materially prejudices the Company. 

19. Notices. All notices, requests, demands and other communications hereunder shall be in writing and shall be deemed to have been duly
given if (i) delivered by hand and receipted for by the party to whom said notice or other communication shall have been directed, or (ii) mailed by certified or registered mail with postage prepaid, on the second business day after the
date on which it is so mailed: 
 (a) If to Indemnitee, to the address set forth below Indemnitee’s signature hereto. 

(b) If to the Company, to: 
  

							
		 	 Arsanis, Inc.
 c/o Errik
Anderson
 16 Cavendish Court
 Lebanon, NH 03766

 
 with a copy to:

			
		 	[                            ]	 	
		 	Fax:	 	[                ]	 	
		 	Email:	 	[                ]	 	

  
 11 

 or to such other address as may have been furnished to Indemnitee by the Company or to the Company by Indemnitee,
as the case may be. 
 20. Identical Counterparts. This Agreement may be executed in one or more counterparts, each of which shall for
all purposes be deemed to be an original but all of which together shall constitute one and the same Agreement. Only one such counterpart signed by the party against whom enforceability is sought needs to be produced to evidence the existence of
this Agreement. 
 21. Headings. The headings of the paragraphs of this Agreement are inserted for convenience only and shall not be
deemed to constitute part of this Agreement or to affect the construction thereof. 
 22. Governing Law. The parties agree that this
Agreement shall be governed by, and construed and enforced in accordance with, the laws of the State of Delaware without application of the conflict of laws principles thereof. 

  
 12 

 IN WITNESS WHEREOF, the parties hereto have executed this Agreement on and as of the day and year
first above written. 
  

			
	ARSANIS, INC.
		
	By:	 	                                      
                                         
                
	Name:
	Title:
	
	INDEMNITEE
	
	  

	Name: 
	Address: 

  
 -13-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00275-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00275-of-00352.parquet"}]]