EX-10.4





 Exhibit 10.4 

KEROS THERAPEUTICS, INC. 

2020 EQUITY INCENTIVE PLAN 

ADOPTED BY THE BOARD OF DIRECTORS:
MARCH 31, 2020 
 APPROVED BY THE STOCKHOLDERS:
MARCH 31, 2020 
  












 TABLE OF CONTENTS 

 

							
	 	 	 	  	Page	 
	 1.
	 	 General
	  	 	1	 
			
	 2.
	 	 Shares Subject to the Plan
	  	 	1	 
			
	 3.
	 	 Eligibility and Limitations
	  	 	2	 
			
	 4.
	 	 Options and Stock Appreciation Rights
	  	 	3	 
			
	 5.
	 	 Awards Other Than Options and Stock Appreciation Rights
	  	 	7	 
			
	 6.
	 	 Adjustments upon Changes in Common Stock; Other Corporate Events
	  	 	9	 
			
	 7.
	 	 Administration
	  	 	11	 
			
	 8.
	 	 Tax Withholding
	  	 	14	 
			
	 9.
	 	 Miscellaneous
	  	 	15	 
			
	 10.
	 	 Covenants of the Company
	  	 	18	 
			
	 11.
	 	 Additional Rules for Awards Subject to Section 409A
	  	 	18	 
			
	 12.
	 	 Severability
	  	 	22	 
			
	 13.
	 	 Termination of the Plan
	  	 	22	 
			
	 14.
	 	 Definitions
	  	 	23	 


  
 i. 













 1.    GENERAL. 

(a)    Successor to and Continuation of Prior Plan. The Plan is the successor to and continuation of the
Prior Plan. As of the Effective Date, (i) no additional awards may be granted under the Prior Plan; (ii) the Prior Plan’s Available Reserve plus any Returning Shares will become available for issuance pursuant to Awards granted under
this Plan; and (iii) all outstanding awards granted under the Prior Plan will remain subject to the terms of the Prior Plan (except to the extent such outstanding awards result in Returning Shares that become available for issuance pursuant to
Awards granted under this Plan). All Awards granted under this Plan will be subject to the terms of this Plan. 

(b)    Plan Purpose. The Company, by means of the Plan, seeks to secure and retain the services of
Employees, Directors and Consultants, to provide incentives for such persons to exert maximum efforts for the success of the Company and any Affiliate and to provide a means by which such persons may be given an opportunity to benefit from increases
in value of the Common Stock through the granting of Awards. 
 (c)    Available Awards. The Plan provides
for the grant of the following Awards: (i) Incentive Stock Options; (ii) Nonstatutory Stock Options; (iii) SARs; (iv) Restricted Stock Awards; (v) RSU Awards; (vi) Performance Awards; and (vii) Other Awards. 

(d)    Adoption Date; Effective Date. The Plan will come into existence on the Adoption Date, but no Award
may be granted prior to the Effective Date. 
 2.    SHARES SUBJECT TO
THE PLAN. 
 (a)    Share Reserve. Subject to adjustment in accordance
with Section 2(c) and any adjustments as necessary to implement any Capitalization Adjustments, the aggregate number of shares of Common Stock that may be issued pursuant to Awards will not exceed 3,107,811 shares, which number is the sum of:
(i) 1,002,874 new shares, plus (ii) the Prior Plan’s Available Reserve; plus, (iii) the number of Returning Shares, if any, as such shares become available from time to time. 

In addition, subject to any adjustments as necessary to implement any Capitalization Adjustments, such aggregate number of shares of Common Stock will
automatically increase on January 1 of each year for a period of ten years commencing on January 1, 2021 and ending on (and including) January 1, 2030, in an amount equal to 4.0% of the total number of shares of Common Stock
outstanding on December 31 of the preceding year; provided, however that the Board may act prior to January 1st of a given year to provide that the increase for such year will be a lesser
number of shares of Common Stock. 
 (b)    Aggregate Incentive Stock Option Limit. Notwithstanding
anything to the contrary in Section 2(a) and subject to any adjustments as necessary to implement any Capitalization Adjustments, the aggregate maximum number of shares of Common Stock that may be issued pursuant to the exercise of Incentive
Stock Options is 9,323,434 shares. 

  
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 (c)    Share Reserve Operation. 

(i)    Limit Applies to Common Stock Issued Pursuant to Awards. For clarity, the Share Reserve is a limit on
the number of shares of Common Stock that may be issued pursuant to Awards and does not limit the granting of Awards, except that the Company will keep available at all times the number of shares of Common Stock reasonably required to satisfy its
obligations to issue shares pursuant to such Awards. Shares may be issued in connection with a merger or acquisition as permitted by, as applicable, Nasdaq Listing Rule 5635(c), NYSE Listed Company Manual Section 303A.08, NYSE American Company
Guide Section 711 or other applicable rule, and such issuance will not reduce the number of shares available for issuance under the Plan. 

(ii)    Actions that Do Not Constitute Issuance of Common Stock and Do Not Reduce Share Reserve. The
following actions do not result in an issuance of shares under the Plan and accordingly do not reduce the number of shares subject to the Share Reserve and available for issuance under the Plan: (1) the expiration or termination of any portion
of an Award without the shares covered by such portion of the Award having been issued; (2) the settlement of any portion of an Award in cash (i.e., the Participant receives cash rather than Common Stock); (3) the withholding of shares
that would otherwise be issued by the Company to satisfy the exercise, strike or purchase price of an Award; or (4) the withholding of shares that would otherwise be issued by the Company to satisfy a tax withholding obligation in connection
with an Award. 
 (iii)    Reversion of Previously Issued Shares of Common Stock to Share Reserve. The
following shares of Common Stock previously issued pursuant to an Award and accordingly initially deducted from the Share Reserve will be added back to the Share Reserve and again become available for issuance under the Plan: (1) any shares
that are forfeited back to or repurchased by the Company because of a failure to meet a contingency or condition required for the vesting of such shares; (2) any shares that are reacquired by the Company to satisfy the exercise, strike or
purchase price of an Award; and (3) any shares that are reacquired by the Company to satisfy a tax withholding obligation in connection with an Award. 

3.    ELIGIBILITY AND LIMITATIONS. 

(a)    Eligible Award Recipients. Subject to the terms of the Plan, Employees, Directors and Consultants are
eligible to receive Awards. 
 (b)    Specific Award Limitations. 

(i)    Limitations on Incentive Stock Option Recipients. Incentive Stock Options may be granted only to
Employees of the Company or a “parent corporation” or “subsidiary corporation” thereof (as such terms are defined in Sections 424(e) and (f) of the Code). 

(ii)    Incentive Stock Option $100,000 Limitation. To the extent that the aggregate Fair Market Value
(determined at the time of grant) of Common Stock with respect to which Incentive Stock Options are exercisable for the first time by any Optionholder during any calendar year (under all plans of the Company and any Affiliates) exceeds $100,000 (or
such 

  
 2. 













 
other limit established in the Code) or otherwise does not comply with the rules governing Incentive Stock Options, the Options or portions thereof that exceed such limit (according to the order
in which they were granted) or otherwise do not comply with such rules will be treated as Nonstatutory Stock Options, notwithstanding any contrary provision of the applicable Option Agreement(s). 

(iii)    Limitations on Incentive Stock Options Granted to Ten Percent Stockholders. A Ten Percent
Stockholder may not be granted an Incentive Stock Option unless (i) the exercise price of such Option is at least 110% of the Fair Market Value on the date of grant of such Option and (ii) the Option is not exercisable after the expiration
of five years from the date of grant of such Option. 
 (iv)    Limitations on Nonstatutory Stock Options and
SARs. Nonstatutory Stock Options and SARs may not be granted to Employees, Directors and Consultants who are providing Continuous Service only to any “parent” of the Company (as such term is defined in Rule 405) unless the stock
underlying such Awards is treated as “service recipient stock” under Section 409A because the Awards are granted pursuant to a corporate transaction (such as a spin off transaction) or unless such Awards otherwise comply with the
distribution requirements of Section 409A. 
 (c)    Aggregate Incentive Stock Option Limit. The
aggregate maximum number of shares of Common Stock that may be issued pursuant to the exercise of Incentive Stock Options is the number of shares specified in Section 2(b). 

(d)    Non-Employee Director Compensation Limit. The aggregate value
of all compensation granted or paid, as applicable, to any individual for service as a Non-Employee Director with respect to any period commencing on the date of the Company’s Annual Meeting of
Stockholders for a particular year and ending on the day immediately prior to the date of the Company’s Annual Meeting of Stockholders for the next subsequent year, including Awards granted and cash fees paid by the Company to such Non-Employee Director, will not exceed (i) $500,000 in total value or (ii) in the event such Non-Employee Director is first appointed or elected to the Board during such
period, $700,000 in total value, in each case calculating the value of any equity awards based on the grant date fair value of such equity awards for financial reporting purposes.

4.    OPTIONS AND STOCK APPRECIATION RIGHTS. 

Each Option and SAR will have such terms and conditions as determined by the Board. Each Option will be designated in writing as an Incentive
Stock Option or Nonstatutory Stock Option at the time of grant; provided, however, that if an Option is not so designated, then such Option will be a Nonstatutory Stock Option, and the shares purchased upon exercise of each type of Option will be
separately accounted for. Each SAR will be denominated in shares of Common Stock equivalents. The terms and conditions of separate Options and SARs need not be identical; provided, however, that each Option Agreement and SAR Agreement will conform


  
 3. 













 
(through incorporation of provisions hereof by reference in the Award Agreement or otherwise) to the substance of each of the following provisions: 

(a)    Term. Subject to Section 3(b) regarding Ten Percent Stockholders, no Option or SAR will be
exercisable after the expiration of ten years from the date of grant of such Award or such shorter period specified in the Award Agreement. 

(b)    Exercise or Strike Price. Subject to Section 3(b) regarding Ten Percent Stockholders, the
exercise or strike price of each Option or SAR will not be less than 100% of the Fair Market Value on the date of grant of such Award. Notwithstanding the foregoing, an Option or SAR may be granted with an exercise or strike price lower than 100% of
the Fair Market Value on the date of grant of such Award if such Award is granted pursuant to an assumption of or substitution for another option or stock appreciation right pursuant to a Corporate Transaction and in a manner consistent with the
provisions of Sections 409A and, if applicable, 424(a) of the Code. 
 (c)    Exercise Procedure and Payment
of Exercise Price for Options. In order to exercise an Option, the Participant must provide notice of exercise to the Plan Administrator in accordance with the procedures specified in the Option Agreement or otherwise provided by the Company.
The Board has the authority to grant Options that do not permit all of the following methods of payment (or otherwise restrict the ability to use certain methods) and to grant Options that require the consent of the Company to utilize a particular
method of payment. The exercise price of an Option may be paid, to the extent permitted by Applicable Law and as determined by the Board, by one or more of the following methods of payment to the extent set forth in the Option Agreement: 

(i)    by cash or check, bank draft or money order payable to the Company; 

(ii)    pursuant to a “cashless exercise” program developed under Regulation T as promulgated by the
Federal Reserve Board that, prior to the issuance of the Common Stock subject to the Option, results in either the receipt of cash (or check) by the Company or the receipt of irrevocable instructions to pay the exercise price to the Company from the
sales proceeds; 
 (iii)    by delivery to the Company (either by actual delivery or attestation) of shares of
Common Stock that are already owned by the Participant free and clear of any liens, claims, encumbrances or security interests, with a Fair Market Value on the date of exercise that does not exceed the exercise price, provided that (1) at the
time of exercise the Common Stock is publicly traded, (2) any remaining balance of the exercise price not satisfied by such delivery is paid by the Participant in cash or other permitted form of payment, (3) such delivery would not violate
any Applicable Law or agreement restricting the redemption of the Common Stock, (4) any certificated shares are endorsed or accompanied by an executed assignment separate from certificate, and (5) such shares have been held by the
Participant for any minimum period necessary to avoid adverse accounting treatment as a result of such delivery; 

(iv)    if the Option is a Nonstatutory Stock Option, by a “net exercise” arrangement pursuant to which
the Company will reduce the number of shares of Common Stock issuable upon exercise by the largest whole number of shares with a Fair Market Value on the date of exercise that does not exceed the exercise price, provided that (1) such shares
used to pay the exercise price will not be exercisable thereafter and (2) any remaining balance of the exercise price not satisfied by such net exercise is paid by the Participant in cash or other permitted form of payment; or 

  
 4. 













 (v)    in any other form of consideration that may be acceptable
to the Board and permissible under Applicable Law. 
 (d)    Exercise Procedure and Payment of Appreciation
Distribution for SARs. In order to exercise any SAR, the Participant must provide notice of exercise to the Plan Administrator in accordance with the SAR Agreement. The appreciation distribution payable to a Participant upon the exercise
of a SAR will not be greater than an amount equal to the excess of (i) the aggregate Fair Market Value on the date of exercise of a number of shares of Common Stock equal to the number of Common Stock equivalents that are vested and being
exercised under such SAR, over (ii) the strike price of such SAR. Such appreciation distribution may be paid to the Participant in the form of Common Stock or cash (or any combination of Common Stock and cash) or in any other form of payment,
as determined by the Board and specified in the SAR Agreement. 
 (e)    Transferability. Options and SARs
may not be transferred to third party financial institutions for value. The Board may impose such additional limitations on the transferability of an Option or SAR as it determines. In the absence of any such determination by the Board, the
following restrictions on the transferability of Options and SARs will apply, provided that except as explicitly provided herein, neither an Option nor a SAR may be transferred for consideration and provided, further, that if an Option is an
Incentive Stock Option, such Option may be deemed to be a Nonstatutory Stock Option as a result of such transfer: 

(i)    Restrictions on Transfer. An Option or SAR will not be transferable, except by will or by the laws of
descent and distribution, and will be exercisable during the lifetime of the Participant only by the Participant; provided, however, that the Board may permit transfer of an Option or SAR in a manner that is not prohibited by applicable tax and
securities laws upon the Participant’s request, including to a trust if the Participant is considered to be the sole beneficial owner of such trust (as determined under Section 671 of the Code and applicable state law) while such Option or
SAR is held in such trust, provided that the Participant and the trustee enter into a transfer and other agreements required by the Company. 

(ii)    Domestic Relations Orders. Notwithstanding the foregoing, subject to the execution of transfer
documentation in a format acceptable to the Company and subject to the approval of the Board or a duly authorized Officer, an Option or SAR may be transferred pursuant to a domestic relations order. 

(f)    Vesting. The Board may impose such restrictions on or conditions to the vesting and/or exercisability
of an Option or SAR as determined by the Board. Except as otherwise provided in the Award Agreement or other written agreement between a Participant and the Company or an Affiliate, vesting of Options and SARs will cease upon termination of the
Participant’s Continuous Service. 

  
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 (g)    Termination of Continuous Service for Cause. Except
as explicitly otherwise provided in the Award Agreement or other written agreement between a Participant and the Company or an Affiliate, if a Participant’s Continuous Service is terminated for Cause, the Participant’s Options and SARs
will terminate and be forfeited immediately upon such termination of Continuous Service, and the Participant will be prohibited from exercising any portion (including any vested portion) of such Awards on and after the date of such termination of
Continuous Service and the Participant will have no further right, title or interest in such forfeited Award, the shares of Common Stock subject to the forfeited Award, or any consideration in respect of the forfeited Award. 

(h)    Post-Termination Exercise Period Following Termination of Continuous Service for Reasons Other than
Cause. Subject to Section 4(i), if a Participant’s Continuous Service terminates for any reason other than for Cause, the Participant may exercise his or her Option or SAR to the extent vested, but only within the following period of
time or, if applicable, such other period of time provided in the Award Agreement or other written agreement between a Participant and the Company or an Affiliate; provided, however, that in no event may such Award be exercised after the expiration
of its maximum term (as set forth in Section 4(a)): 
 (i)    three months following the date of such
termination if such termination is a termination without Cause (other than any termination due to the Participant’s Disability or death); 

(ii)    12 months following the date of such termination if such termination is due to the Participant’s
Disability; 
 (iii)    24 months following the date of such termination if such termination is due to the
Participant’s death; or 
 (iv)    24 months following the date of the Participant’s death if such
death occurs following the date of such termination but during the period such Award is otherwise exercisable (as provided in (i) or (ii) above). 

Following the date of such termination, to the extent the Participant does not exercise such Award within the applicable Post-Termination Exercise Period (or,
if earlier, prior to the expiration of the maximum term of such Award), such unexercised portion of the Award will terminate, and the Participant will have no further right, title or interest in terminated Award, the shares of Common Stock subject
to the terminated Award, or any consideration in respect of the terminated Award. 
 (i)    Restrictions on
Exercise; Extension of Exercisability. A Participant may not exercise an Option or SAR at any time that the issuance of shares of Common Stock upon such exercise would violate Applicable Law. Except as otherwise provided in the Award Agreement
or other written agreement between a Participant and the Company or an Affiliate, if a Participant’s Continuous Service terminates for any reason other than for Cause and, at any time during the last thirty days of the applicable
Post-Termination Exercise Period: (i) the exercise of the Participant’s Option or SAR would be prohibited solely because the issuance of shares of Common Stock upon such exercise would violate Applicable Law, or (ii) the immediate
sale of 

  
 6. 













 
any shares of Common Stock issued upon such exercise would violate the Company’s Trading Policy, then the applicable Post-Termination Exercise Period will be extended to the last day of the
calendar month that commences following the date the Award would otherwise expire, with an additional extension of the exercise period to the last day of the next calendar month to apply if any of the foregoing restrictions apply at any time during
such extended exercise period, generally without limitation as to the maximum permitted number of extensions); provided, however, that in no event may such Award be exercised after the expiration of its maximum term (as set forth in
Section 4(a)). 
 (j)    Non-Exempt Employees. No
Option or SAR, whether or not vested, granted to an Employee who is a non-exempt employee for purposes of the Fair Labor Standards Act of 1938, as amended, will be first exercisable for any shares of Common
Stock until at least six months following the date of grant of such Award. Notwithstanding the foregoing, in accordance with the provisions of the Worker Economic Opportunity Act, any vested portion of such Award may be exercised earlier than six
months following the date of grant of such Award in the event of (i) such Participant’s death or Disability, (ii) a Corporate Transaction in which such Award is not assumed, continued or substituted, (iii) a Change in Control, or
(iv) such Participant’s retirement (as such term may be defined in the Award Agreement or another applicable agreement or, in the absence of any such definition, in accordance with the Company’s then current employment policies and
guidelines). This Section 4(j) is intended to operate so that any income derived by a non-exempt employee in connection with the exercise or vesting of an Option or SAR will be exempt from his or her
regular rate of pay. 
 (k)    Whole Shares. Options and SARs may be exercised only with respect to whole
shares of Common Stock or their equivalents. 
 5.    AWARDS OTHER THAN
OPTIONS AND STOCK APPRECIATION RIGHTS. 

(a)    Restricted Stock Awards and RSU Awards. Each Restricted Stock Award and RSU Award will have such terms
and conditions as determined by the Board; provided, however, that each Restricted Stock Award Agreement and RSU Award Agreement will conform (through incorporation of the provisions hereof by reference in the Award Agreement or otherwise) to the
substance of each of the following provisions: 
 (i)    Form of Award. 

(1)    RSAs: To the extent consistent with the Company’s Bylaws, at the Board’s election, shares of
Common Stock subject to a Restricted Stock Award may be (i) held in book entry form subject to the Company’s instructions until such shares become vested or any other restrictions lapse, or (ii) evidenced by a certificate, which
certificate will be held in such form and manner as determined by the Board. Unless otherwise determined by the Board, a Participant will have voting and other rights as a stockholder of the Company with respect to any shares subject to a Restricted
Stock Award. 
 (2)    RSUs: A RSU Award represents a Participant’s right to be issued on a future date the
number of shares of Common Stock that is equal to the number of restricted stock units subject to the RSU Award. As a holder of a RSU Award, a Participant is an 

  
 7. 













 
unsecured creditor of the Company with respect to the Company’s unfunded obligation, if any, to issue shares of Common Stock in settlement of such Award and nothing contained in the Plan or
any RSU Agreement, and no action taken pursuant to its provisions, will create or be construed to create a trust of any kind or a fiduciary relationship between a Participant and the Company or an Affiliate or any other person. A Participant will
not have voting or any other rights as a stockholder of the Company with respect to any RSU Award (unless and until shares are actually issued in settlement of a vested RSU Award). 

(ii)    Consideration. 

(1)    RSA: A Restricted Stock Award may be granted in consideration for (A) cash or check, bank draft or
money order payable to the Company, (B) past services to the Company or an Affiliate, or (C) any other form of consideration (including future services) as the Board may determine and permissible under Applicable Law. 

(2)    RSU: Unless otherwise determined by the Board at the time of grant, a RSU Award will be granted in
consideration for the Participant’s services to the Company or an Affiliate, such that the Participant will not be required to make any payment to the Company (other than such services) with respect to the grant or vesting of the RSU Award, or
the issuance of any shares of Common Stock pursuant to the RSU Award. If, at the time of grant, the Board determines that any consideration must be paid by the Participant (in a form other than the Participant’s services to the Company or an
Affiliate) upon the issuance of any shares of Common Stock in settlement of the RSU Award, such consideration may be paid in any form of consideration as the Board may determine and permissible under Applicable Law. 

(iii)    Vesting. The Board may impose such restrictions on or conditions to the vesting of a Restricted
Stock Award or RSU Award as determined by the Board. Except as otherwise provided in the Award Agreement or other written agreement between a Participant and the Company or an Affiliate, vesting of Restricted Stock Awards and RSU Awards will cease
upon termination of the Participant’s Continuous Service. 
 (iv)    Termination of Continuous
Service. Except as otherwise provided in the Award Agreement or other written agreement between a Participant and the Company or an Affiliate, if a Participant’s Continuous Service terminates for any reason, (i) the Company may receive
through a forfeiture condition or a repurchase right any or all of the shares of Common Stock held by the Participant under his or her Restricted Stock Award that have not vested as of the date of such termination as set forth in the Restricted
Stock Award Agreement and (ii) any portion of his or her RSU Award that has not vested will be forfeited upon such termination and the Participant will have no further right, title or interest in the RSU Award, the shares of Common Stock
issuable pursuant to the RSU Award, or any consideration in respect of the RSU Award. 
 (v)    Dividends and
Dividend Equivalents. Dividends or dividend equivalents may be paid or credited, as applicable, with respect to any shares of Common Stock subject to a Restricted Stock Award or RSU Award, as determined by the Board and specified in the Award
Agreement). 

  
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 (vi)    Settlement of RSU Awards. A RSU Award may be
settled by the issuance of shares of Common Stock or cash (or any combination thereof) or in any other form of payment, as determined by the Board and specified in the RSU Award Agreement. At the time of grant, the Board may determine to impose such
restrictions or conditions that delay such delivery to a date following the vesting of the RSU Award. 

(b)    Performance Awards. With respect to any Performance Award, the length of any Performance Period, the
Performance Goals to be achieved during the Performance Period, the other terms and conditions of such Award, and the measure of whether and to what degree such Performance Goals have been attained will be determined by the Board. 

(c)    Other Awards. Other forms of Awards valued in whole or in part by reference to, or otherwise based
on, Common Stock, including the appreciation in value thereof (e.g., options or stock rights with an exercise price or strike price less than 100% of the Fair Market Value at the time of grant) may be granted either alone or in addition to Awards
provided for under Section 4 and the preceding provisions of this Section 5. Subject to the provisions of the Plan, the Board will have sole and complete discretion to determine the persons to whom and the time or times at which such Other
Awards will be granted, the number of shares of Common Stock (or the cash equivalent thereof) to be granted pursuant to such Other Awards and all other terms and conditions of such Other Awards. 

6.    ADJUSTMENTS UPON CHANGES IN COMMON
STOCK; OTHER CORPORATE EVENTS. 

(a)    Capitalization Adjustments. In the event of a Capitalization Adjustment, the Board shall appropriately
and proportionately adjust: (i) the class(es) and maximum number of shares of Common Stock subject to the Plan and the maximum number of shares by which the Share Reserve may annually increase pursuant to Section 2(a); (ii) the class(es)
and maximum number of shares that may be issued pursuant to the exercise of Incentive Stock Options pursuant to Section 2(a); and (iii) the class(es) and number of securities and exercise price, strike price or purchase price of Common
Stock subject to outstanding Awards. The Board shall make such adjustments, and its determination shall be final, binding and conclusive. Notwithstanding the foregoing, no fractional shares or rights for fractional shares of Common Stock shall be
created in order to implement any Capitalization Adjustment. The Board shall determine an appropriate equivalent benefit, if any, for any fractional shares or rights to fractional shares that might be created by the adjustments referred to in the
preceding provisions of this Section. 
 (b)    Dissolution or Liquidation. Except as otherwise provided
in the Award Agreement, in the event of a dissolution or liquidation of the Company, all outstanding Awards (other than Awards consisting of vested and outstanding shares of Common Stock not subject to a forfeiture condition or the Company’s
right of repurchase) will terminate immediately prior to the completion of such dissolution or liquidation, and the shares of Common Stock subject to the Company’s repurchase rights or subject to a forfeiture condition may be repurchased or
reacquired by the Company notwithstanding the fact that the holder of such Award is providing Continuous Service, provided, however, that the Board may determine to cause some or all Awards to become fully vested, exercisable and/or no longer
subject to repurchase or forfeiture (to the extent such Awards have not previously expired or terminated) before the dissolution or liquidation is completed but contingent on its completion. 

  
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 (c)    Corporate Transaction. The following provisions
will apply to Awards in the event of a Corporate Transaction unless otherwise provided in the instrument evidencing the Award or any other written agreement between the Company or any Affiliate and the Participant or unless otherwise expressly
provided by the Board at the time of grant of an Award. 
 (i)    Awards May Be Assumed. In the event of a
Corporate Transaction, any surviving corporation or acquiring corporation (or the surviving or acquiring corporation’s parent company) may assume or continue any or all Awards outstanding under the Plan or may substitute similar awards for
Awards outstanding under the Plan (including but not limited to, awards to acquire the same consideration paid to the stockholders of the Company pursuant to the Corporate Transaction), and any reacquisition or repurchase rights held by the Company
in respect of Common Stock issued pursuant to Awards may be assigned by the Company to the successor of the Company (or the successor’s parent company, if any), in connection with such Corporate Transaction. A surviving corporation or acquiring
corporation (or its parent) may choose to assume or continue only a portion of an Award or substitute a similar award for only a portion of an Award, or may choose to assume or continue the Awards held by some, but not all Participants. The terms of
any assumption, continuation or substitution will be set by the Board. 
 (ii)    Awards Held by Current
Participants. In the event of a Corporate Transaction in which the surviving corporation or acquiring corporation (or its parent company) does not assume or continue such outstanding Awards or substitute similar awards for such outstanding
Awards, then with respect to Awards that have not been assumed, continued or substituted and that are held by Participants whose Continuous Service has not terminated prior to the effective time of the Corporate Transaction (referred to as the
“Current Participants”), the vesting of such Awards (and, with respect to Options and Stock Appreciation Rights, the time when such Awards may be exercised) will be accelerated in full to a date prior to the effective
time of such Corporate Transaction (contingent upon the effectiveness of the Corporate Transaction) as the Board determines (or, if the Board does not determine such a date, to the date that is five (5) days prior to the effective time of the
Corporate Transaction), and such Awards will terminate if not exercised (if applicable) at or prior to the effective time of the Corporate Transaction, and any reacquisition or repurchase rights held by the Company with respect to such Awards will
lapse (contingent upon the effectiveness of the Corporate Transaction). With respect to the vesting of Performance Awards that will accelerate upon the occurrence of a Corporate Transaction pursuant to this subsection (ii) and that have
multiple vesting levels depending on the level of performance, unless otherwise provided in the Award Agreement or unless otherwise provided by the Board, the vesting of such Performance Awards will accelerate at 100% of the target level upon the
occurrence of the Corporate Transaction. With respect to the vesting of Awards that will accelerate upon the occurrence of a Corporate Transaction pursuant to this subsection (ii) and are settled in the form of a cash payment, such cash payment
will be made no later than 30 days following the occurrence of the Corporate Transaction. 
 (iii)    Awards
Held by Persons other than Current Participants. In the event of a Corporate Transaction in which the surviving corporation or acquiring corporation (or its parent company) does not assume or continue such outstanding Awards or substitute
similar awards for such outstanding Awards, then with respect to Awards that have not been assumed, continued or substituted and that are held by persons other than Current Participants, 

  
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such Awards will terminate if not exercised (if applicable) prior to the occurrence of the Corporate Transaction; provided, however, that any reacquisition or repurchase rights held by the
Company with respect to such Awards will not terminate and may continue to be exercised notwithstanding the Corporate Transaction. 

(iv)    Payment for Awards in Lieu of Exercise. Notwithstanding the foregoing, in the event an Award will
terminate if not exercised prior to the effective time of a Corporate Transaction, the Board may provide, in its sole discretion, that the holder of such Award may not exercise such Award but will receive a payment, in such form as may be determined
by the Board, equal in value, at the effective time, to the excess, if any, of (1) the value of the property the Participant would have received upon the exercise of the Award (including, at the discretion of the Board, any unvested portion of
such Award), over (2) any exercise price payable by such holder in connection with such exercise. 

(d)    Appointment of Stockholder Representative. As a condition to the receipt of an Award under this Plan,
a Participant will be deemed to have agreed that the Award will be subject to the terms of any agreement governing a Corporate Transaction involving the Company, including, without limitation, a provision for the appointment of a stockholder
representative that is authorized to act on the Participant’s behalf with respect to any escrow, indemnities and any contingent consideration. 

(e)    No Restriction on Right to Undertake Transactions. The grant of any Award under the Plan and the
issuance of shares pursuant to any Award does not affect or restrict in any way the right or power of the Company or the stockholders of the Company to make or authorize any adjustment, recapitalization, reorganization or other change in the
Company’s capital structure or its business, any merger or consolidation of the Company, any issue of stock or of options, rights or options to purchase stock or of bonds, debentures, preferred or prior preference stocks whose rights are
superior to or affect the Common Stock or the rights thereof or which are convertible into or exchangeable for Common Stock, or the dissolution or liquidation of the Company, or any sale or transfer of all or any part of its assets or business, or
any other corporate act or proceeding, whether of a similar character or otherwise. 
 7.    ADMINISTRATION. 

(a)    Administration by Board. The Board will administer the Plan unless and until the Board delegates
administration of the Plan to a Committee or Committees, as provided in subsection (c) below. 

(b)    Powers of Board. The Board will have the power, subject to, and within the limitations of, the
express provisions of the Plan: 
 (i)    To determine from time to time (1) which of the persons eligible
under the Plan will be granted Awards; (2) when and how each Award will be granted; (3) what type or combination of types of Award will be granted; (4) the provisions of each Award granted (which need not be identical), including the
time or times when a person will be permitted to receive an issuance of Common Stock or other payment pursuant to an Award; (5) the number of shares of Common Stock or cash equivalent with respect to which an Award will be granted


  
 11. 













 
to each such person; (6) the Fair Market Value applicable to an Award; and (7) the terms of any Performance Award that is not valued in whole or in part by reference to, or otherwise
based on, the Common Stock, including the amount of cash payment or other property that may be earned and the timing of payment. 

(ii)    To construe and interpret the Plan and Awards granted under it, and to establish, amend and revoke rules
and regulations for its administration. The Board, in the exercise of this power, may correct any defect, omission or inconsistency in the Plan or in any Award Agreement, in a manner and to the extent it deems necessary or expedient to make the Plan
or Award fully effective. 
 (iii)    To settle all controversies regarding the Plan and Awards granted under it.

 (iv)    To accelerate the time at which an Award may first be exercised or the time during which an Award or
any part thereof will vest, notwithstanding the provisions in the Award Agreement stating the time at which it may first be exercised or the time during which it will vest. 

(v)    To prohibit the exercise of any Option, SAR or other exercisable Award during a period of up to 30 days
prior to the consummation of any pending stock dividend, stock split, combination or exchange of shares, merger, consolidation or other distribution (other than normal cash dividends) of Company assets to stockholders, or any other change affecting
the shares of Common Stock or the share price of the Common Stock including any Corporate Transaction, for reasons of administrative convenience. 

(vi)    To suspend or terminate the Plan at any time. Suspension or termination of the Plan will not Materially
Impair rights and obligations under any Award granted while the Plan is in effect except with the written consent of the affected Participant. 

(vii)    To amend the Plan in any respect the Board deems necessary or advisable; provided, however, that
stockholder approval will be required for any amendment to the extent required by Applicable Law. Except as provided above, rights under any Award granted before amendment of the Plan will not be Materially Impaired by any amendment of the Plan
unless (1) the Company requests the consent of the affected Participant, and (2) such Participant consents in writing. 

(viii)    To submit any amendment to the Plan for stockholder approval. 

(ix)    To approve forms of Award Agreements for use under the Plan and to amend the terms of any one or more
Awards, including, but not limited to, amendments to provide terms more favorable to the Participant than previously provided in the Award Agreement, subject to any specified limits in the Plan that are not subject to Board discretion; provided
however, that, a Participant’s rights under any Award will not be Materially Impaired by any such amendment unless (1) the Company requests the consent of the affected Participant, and (2) such Participant consents in writing.


  
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 (x)    Generally, to exercise such powers and to perform such
acts as the Board deems necessary or expedient to promote the best interests of the Company and that are not in conflict with the provisions of the Plan or Awards. 

(xi)    To adopt such procedures and sub-plans as are necessary or
appropriate to permit and facilitate participation in the Plan by, or take advantage of specific tax treatment for Awards granted to, Employees, Directors or Consultants who are foreign nationals or employed outside the United States (provided that
Board approval will not be necessary for immaterial modifications to the Plan or any Award Agreement to ensure or facilitate compliance with the laws of the relevant foreign jurisdiction). 

(xii)    To effect, at any time and from time to time, subject to the consent of any Participant whose Award is
Materially Impaired by such action, (1) the reduction of the exercise price (or strike price) of any outstanding Option or SAR; (2) the cancellation of any outstanding Option or SAR and the grant in substitution therefor of (A) a new
Option, SAR, Restricted Stock Award, RSU Award or Other Award, under the Plan or another equity plan of the Company, covering the same or a different number of shares of Common Stock, (B) cash and/or (C) other valuable consideration (as
determined by the Board); or (3) any other action that is treated as a repricing under generally accepted accounting principles. 

(c)    Delegation to Committee. 

(i)    General. The Board may delegate some or all of the administration of the Plan to a Committee or
Committees. If administration of the Plan is delegated to a Committee, the Committee will have, in connection with the administration of the Plan, the powers theretofore possessed by the Board that have been delegated to the Committee, including the
power to delegate to another Committee or a subcommittee of the Committee any of the administrative powers the Committee is authorized to exercise (and references in this Plan to the Board will thereafter be to the Committee or subcommittee),
subject, however, to such resolutions, not inconsistent with the provisions of the Plan, as may be adopted from time to time by the Board. Each Committee may retain the authority to concurrently administer the Plan with Committee or subcommittee to
which it has delegated its authority hereunder and may, at any time, revest in such Committee some or all of the powers previously delegated. The Board may retain the authority to concurrently administer the Plan with any Committee and may, at any
time, revest in the Board some or all of the powers previously delegated. 
 (ii)    Rule 16b-3 Compliance. To the extent an Award is intended to qualify for the exemption from Section 16(b) of the Exchange Act that is available under Rule 16b-3 of the
Exchange Act, the Award will be granted by the Board or a Committee that consists solely of two or more Non-Employee Directors, as determined under Rule 16b-3(b)(3) of
the Exchange Act and thereafter any action establishing or modifying the terms of the Award will be approved by the Board or a Committee meeting such requirements to the extent necessary for such exemption to remain available. 

(d)    Effect of Board’s Decision. All determinations, interpretations and constructions
made by the Board or any Committee in good faith will not be subject to review by any person and will be final, binding and conclusive on all persons. 

  
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 (e)    Delegation to an Officer. The Board or any
Committee may delegate to one or more Officers the authority to do one or both of the following (i) designate Employees who are not Officers to be recipients of Options and SARs (and, to the extent permitted by Applicable Law, other types of
Awards) and, to the extent permitted by Applicable Law, the terms thereof, and (ii) determine the number of shares of Common Stock to be subject to such Awards granted to such Employees; provided, however, that the resolutions or charter
adopted by the Board or any Committee evidencing such delegation will specify the total number of shares of Common Stock that may be subject to the Awards granted by such Officer and that such Officer may not grant an Award to himself or herself.
Any such Awards will be granted on the applicable form of Award Agreement most recently approved for use by the Board or the Committee, unless otherwise provided in the resolutions approving the delegation authority. Notwithstanding anything to the
contrary herein, neither the Board nor any Committee may delegate to an Officer who is acting solely in the capacity of an Officer (and not also as a Director) the authority to determine the Fair Market Value. 

8.    TAX WITHHOLDING 

(a)    Withholding Authorization. As a condition to acceptance of any Award under the Plan, a Participant
authorizes withholding from payroll and any other amounts payable to such Participant, and otherwise agree to make adequate provision for (including), any sums required to satisfy any U.S. federal, state, local and/or foreign tax or social insurance
contribution withholding obligations of the Company or an Affiliate, if any, which arise in connection with the exercise, vesting or settlement of such Award, as applicable. Accordingly, a Participant may not be able to exercise an Award even though
the Award is vested, and the Company shall have no obligation to issue shares of Common Stock subject to an Award, unless and until such obligations are satisfied. 

(b)    Satisfaction of Withholding Obligation. To the extent permitted by the terms of an Award Agreement,
the Company may, in its sole discretion, satisfy any U.S. federal, state, local and/or foreign tax or social insurance withholding obligation relating to an Award by any of the following means or by a combination of such means: (i) causing the
Participant to tender a cash payment; (ii) withholding shares of Common Stock from the shares of Common Stock issued or otherwise issuable to the Participant in connection with the Award; (iii) withholding cash from an Award settled in
cash; (iv) withholding payment from any amounts otherwise payable to the Participant; (v) by allowing a Participant to effectuate a “cashless exercise” pursuant to a program developed under Regulation T as promulgated by the
Federal Reserve Board; or (vi) by such other method as may be set forth in the Award Agreement. 

(c)    No Obligation to Notify or Minimize Taxes; No Liability to Claims. Except as required by Applicable
Law the Company has no duty or obligation to any Participant to advise such holder as to the time or manner of exercising such Award. Furthermore, the Company has no duty or obligation to warn or otherwise advise such holder of a pending termination
or expiration of an Award or a possible period in which the Award may not be exercised. The Company has no duty or obligation to minimize the tax consequences of an Award to the holder of such Award and will not be liable to any holder of an Award
for any adverse tax consequences to such holder in connection with an Award. As a condition to accepting an Award under the Plan, each Participant (i) agrees to not make any claim against the Company, or any of its


  
 14. 













 
Officers, Directors, Employees or Affiliates related to tax liabilities arising from such Award or other Company compensation and (ii) acknowledges that such Participant was advised to
consult with his or her own personal tax, financial and other legal advisors regarding the tax consequences of the Award and has either done so or knowingly and voluntarily declined to do so. Additionally, each Participant acknowledges any Option or
SAR granted under the Plan is exempt from Section 409A only if the exercise or strike price is at least equal to the “fair market value” of the Common Stock on the date of grant as determined by the Internal Revenue Service and there
is no other impermissible deferral of compensation associated with the Award. Additionally, as a condition to accepting an Option or SAR granted under the Plan, each Participant agrees not make any claim against the Company, or any of its Officers,
Directors, Employees or Affiliates in the event that the Internal Revenue Service asserts that such exercise price or strike price is less than the “fair market value” of the Common Stock on the date of grant as subsequently determined by
the Internal Revenue Service. 
 (d)    Withholding Indemnification. As a condition to accepting an Award
under the Plan, in the event that the amount of the Company’s and/or its Affiliate’s withholding obligation in connection with such Award was greater than the amount actually withheld by the Company and/or its Affiliates, each Participant
agrees to indemnify and hold the Company and/or its Affiliates harmless from any failure by the Company and/or its Affiliates to withhold the proper amount. 

9.    MISCELLANEOUS. 

(a)    Source of Shares. The stock issuable under the Plan will be shares of authorized but unissued or
reacquired Common Stock, including shares repurchased by the Company on the open market or otherwise. 

(b)    Use of Proceeds from Sales of Common Stock. Proceeds from the sale of shares of Common Stock pursuant
to Awards will constitute general funds of the Company. 
 (c)    Corporate Action Constituting Grant of
Awards. Corporate action constituting a grant by the Company of an Award to any Participant will be deemed completed as of the date of such corporate action, unless otherwise determined by the Board, regardless of when the instrument,
certificate, or letter evidencing the Award is communicated to, or actually received or accepted by, the Participant. In the event that the corporate records (e.g., Board consents, resolutions or minutes) documenting the corporate action approving
the grant contain terms (e.g., exercise price, vesting schedule or number of shares) that are inconsistent with those in the Award Agreement or related grant documents as a result of a clerical error in the Award Agreement or related grant
documents, the corporate records will control and the Participant will have no legally binding right to the incorrect term in the Award Agreement or related grant documents. 

(d)    Stockholder Rights. No Participant will be deemed to be the holder of, or to have any of the rights
of a holder with respect to, any shares of Common Stock subject to such Award unless and until (i) such Participant has satisfied all requirements for exercise of the Award pursuant to its terms, if applicable, and (ii) the issuance of the
Common Stock subject to such Award is reflected in the records of the Company. 

  
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 (e)    No Employment or Other Service Rights. Nothing in
the Plan, any Award Agreement or any other instrument executed thereunder or in connection with any Award granted pursuant thereto will confer upon any Participant any right to continue to serve the Company or an Affiliate in the capacity in effect
at the time the Award was granted or affect the right of the Company or an Affiliate to terminate at will and without regard to any future vesting opportunity that a Participant may have with respect to any Award (i) the employment of an
Employee with or without notice and with or without cause, (ii) the service of a Consultant pursuant to the terms of such Consultant’s agreement with the Company or an Affiliate, or (iii) the service of a Director pursuant to the
Bylaws of the Company or an Affiliate, and any applicable provisions of the corporate law of the state or foreign jurisdiction in which the Company or the Affiliate is incorporated, as the case may be. Further, nothing in the Plan, any Award
Agreement or any other instrument executed thereunder or in connection with any Award will constitute any promise or commitment by the Company or an Affiliate regarding the fact or nature of future positions, future work assignments, future
compensation or any other term or condition of employment or service or confer any right or benefit under the Award or the Plan unless such right or benefit has specifically accrued under the terms of the Award Agreement and/or Plan. 

(f)    Change in Time Commitment. In the event a Participant’s regular level of time commitment in the
performance of his or her services for the Company and any Affiliates is reduced (for example, and without limitation, if the Participant is an Employee of the Company and the Employee has a change in status from a full-time Employee to a part-time
Employee or takes an extended leave of absence) after the date of grant of any Award to the Participant, the Board may determine, to the extent permitted by Applicable Law, to (i) make a corresponding reduction in the number of shares or cash
amount subject to any portion of such Award that is scheduled to vest or become payable after the date of such change in time commitment, and (ii) in lieu of or in combination with such a reduction, extend the vesting or payment schedule
applicable to such Award. In the event of any such reduction, the Participant will have no right with respect to any portion of the Award that is so reduced or extended. 

(g)    Execution of Additional Documents. As a condition to accepting an Award under the Plan, the
Participant agrees to execute any additional documents or instruments necessary or desirable, as determined in the Plan Administrator’s sole discretion, to carry out the purposes or intent of the Award, or facilitate compliance with securities
and/or other regulatory requirements, in each case at the Plan Administrator’s request. 

(h)    Electronic Delivery and Participation. Any reference herein or in an Award Agreement to a
“written” agreement or document will include any agreement or document delivered electronically, filed publicly at www.sec.gov (or any successor website thereto) or posted on the Company’s intranet (or other shared electronic medium
controlled by the Company to which the Participant has access). By accepting any Award the Participant consents to receive documents by electronic delivery and to participate in the Plan through any on-line
electronic system established and maintained by the Plan Administrator or another third party selected by the Plan Administrator. The form of delivery of any Common Stock (e.g., a stock certificate or electronic entry evidencing such shares) shall
be determined by the Company. 

  
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 (i)    Clawback/Recovery. All Awards granted under the
Plan will be subject to recoupment in accordance with any clawback policy that the Company is required to adopt pursuant to the listing standards of any national securities exchange or association on which the Company’s securities are listed or
as is otherwise required by the Dodd-Frank Wall Street Reform and Consumer Protection Act or other Applicable Law and any clawback policy that the Company otherwise adopts, to the extent applicable and permissible under Applicable Law. In addition,
the Board may impose such other clawback, recovery or recoupment provisions in an Award Agreement as the Board determines necessary or appropriate, including but not limited to a reacquisition right in respect of previously acquired shares of Common
Stock or other cash or property upon the occurrence of Cause. No recovery of compensation under such a clawback policy will be an event giving rise to a Participant’s right to voluntary terminate employment upon a “resignation for good
reason,” or for a “constructive termination” or any similar term under any plan of or agreement with the Company. 

(j)    Securities Law Compliance. A Participant will not be issued any shares in respect of an Award unless
either (i) the shares are registered under the Securities Act; or (ii) the Company has determined that such issuance would be exempt from the registration requirements of the Securities Act. Each Award also must comply with other
Applicable Law governing the Award, and a Participant will not receive such shares if the Company determines that such receipt would not be in material compliance with Applicable Law. 

(k)    Transfer or Assignment of Awards; Issued Shares. Except as expressly provided in the Plan or the form
of Award Agreement, Awards granted under the Plan may not be transferred or assigned by the Participant. After the vested shares subject to an Award have been issued, or in the case of Restricted Stock and similar awards, after the issued shares
have vested, the holder of such shares is free to assign, hypothecate, donate, encumber or otherwise dispose of any interest in such shares provided that any such actions are in compliance with the provisions herein, the terms of the Trading Policy
and Applicable Law. 
 (l)    Effect on Other Employee Benefit Plans. The value of any Award granted under
the Plan, as determined upon grant, vesting or settlement, shall not be included as compensation, earnings, salaries, or other similar terms used when calculating any Participant’s benefits under any employee benefit plan sponsored by the
Company or any Affiliate, except as such plan otherwise expressly provides. The Company expressly reserves its rights to amend, modify, or terminate any of the Company’s or any Affiliate’s employee benefit plans. 

(m)    Deferrals. To the extent permitted by Applicable Law, the Board, in its sole discretion, may
determine that the delivery of Common Stock or the payment of cash, upon the exercise, vesting or settlement of all or a portion of any Award may be deferred and may also establish programs and procedures for deferral elections to be made by
Participants. Deferrals by will be made in accordance with the requirements of Section 409A. 

(n)    Section 409A. Unless otherwise expressly provided for in an Award Agreement, the Plan and Award
Agreements will be interpreted to the greatest extent possible in a manner that makes the Plan and the Awards granted hereunder exempt from Section 409A, and, to the extent not so exempt, in compliance with the requirements of
Section 409A. If the Board determines that any Award granted hereunder is not exempt from and is therefore subject to 

  
 17. 













 
Section 409A, the Award Agreement evidencing such Award will incorporate the terms and conditions necessary to avoid the consequences specified in Section 409A(a)(1) of the Code, and to
the extent an Award Agreement is silent on terms necessary for compliance, such terms are hereby incorporated by reference into the Award Agreement. Notwithstanding anything to the contrary in this Plan (and unless the Award Agreement specifically
provides otherwise), if the shares of Common Stock are publicly traded, and if a Participant holding an Award that constitutes “deferred compensation” under Section 409A is a “specified employee” for purposes of
Section 409A, no distribution or payment of any amount that is due because of a “separation from service” (as defined in Section 409A without regard to alternative definitions thereunder) will be issued or paid before the date
that is six months and one day following the date of such Participant’s “separation from service” or, if earlier, the date of the Participant’s death, unless such distribution or payment can be made in a manner that complies with
Section 409A, and any amounts so deferred will be paid in a lump sum on the day after such six month period elapses, with the balance paid thereafter on the original schedule. 

(o)    CHOICE OF LAW. This Plan and any controversy arising out
of or relating to this Plan shall be governed by, and construed in accordance with, the internal laws of the State of Delaware, without regard to conflict of law principles that would result in any application of any law other than the law of the
State of Delaware. 
 10.    COVENANTS OF THE COMPANY. 

(a)    Compliance with Law. The Company will seek to obtain from each regulatory commission or agency, as may
be deemed to be necessary, having jurisdiction over the Plan such authority as may be required to grant Awards and to issue and sell shares of Common Stock upon exercise or vesting of the Awards; provided, however, that this undertaking will not
require the Company to register under the Securities Act the Plan, any Award or any Common Stock issued or issuable pursuant to any such Award. If, after reasonable efforts and at a reasonable cost, the Company is unable to obtain from any such
regulatory commission or agency the authority that counsel for the Company deems necessary or advisable for the lawful issuance and sale of Common Stock under the Plan, the Company will be relieved from any liability for failure to issue and sell
Common Stock upon exercise or vesting of such Awards unless and until such authority is obtained. A Participant is not eligible for the grant of an Award or the subsequent issuance of Common Stock pursuant to the Award if such grant or issuance
would be in violation of any Applicable Law. 
 11.    ADDITIONAL RULES FOR
AWARDS SUBJECT TO SECTION 409A. 

(a)    Application. Unless the provisions of this Section of the Plan are expressly superseded by the
provisions in the form of Award Agreement, the provisions of this Section shall apply and shall supersede anything to the contrary set forth in the Award Agreement for a Non-Exempt Award. 

(b)    Non-Exempt Awards Subject to
Non-Exempt Severance Arrangements. To the extent a Non-Exempt Award is subject to Section 409A due to application of a
Non-Exempt Severance Arrangement, the following provisions of this subsection (b) apply. 

  
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 (i)    If the Non-Exempt
Award vests in the ordinary course during the Participant’s Continuous Service in accordance with the vesting schedule set forth in the Award Agreement, and does not accelerate vesting under the terms of a
Non-Exempt Severance Arrangement, in no event will the shares be issued in respect of such Non-Exempt Award any later than the later of: (i) December 31st of the calendar year that includes the applicable vesting date, or (ii) the 60th day that follows the applicable vesting date. 

(ii)    If vesting of the Non-Exempt Award accelerates under the terms of a
Non-Exempt Severance Arrangement in connection with the Participant’s Separation from Service, and such vesting acceleration provisions were in effect as of the date of grant of the Non-Exempt Award and, therefore, are part of the terms of such Non-Exempt Award as of the date of grant, then the shares will be earlier issued in settlement of such Non-Exempt Award upon the Participant’s Separation from Service in accordance with the terms of the Non-Exempt Severance Arrangement, but in no event later than the 60th day that follows the date of the Participant’s Separation from Service. However, if at the time the shares would otherwise be issued the Participant is subject to the distribution limitations
contained in Section 409A applicable to “specified employees,” as defined in Section 409A(a)(2)(B)(i) of the Code, such shares shall not be issued before the date that is six months following the date of such Participant’s
Separation from Service, or, if earlier, the date of the Participant’s death that occurs within such six month period. 

(iii)    If vesting of a Non-Exempt Award accelerates under the terms of a Non-Exempt Severance Arrangement in connection with a Participant’s Separation from Service, and such vesting acceleration provisions were not in effect as of the date of grant of the Non-Exempt Award and, therefore, are not a part of the terms of such Non-Exempt Award on the date of grant, then such acceleration of vesting of the Non-Exempt Award shall not accelerate the issuance date of the shares, but the shares shall instead be issued on the same schedule as set forth in the Grant Notice as if they had vested in the ordinary course during
the Participant’s Continuous Service, notwithstanding the vesting acceleration of the Non-Exempt Award. Such issuance schedule is intended to satisfy the requirements of payment on a specified date or
pursuant to a fixed schedule, as provided under Treasury Regulations Section 1.409A-3(a)(4). 

(c)    Treatment of Non-Exempt Awards Upon a Corporate Transaction for
Employees and Consultants. The provisions of this subsection (c) shall apply and shall supersede anything to the contrary set forth in the Plan with respect to the permitted treatment of any
Non-Exempt Award in connection with a Corporate Transaction if the Participant was either an Employee or Consultant upon the applicable date of grant of the Non-Exempt
Award. 
 (i)    Vested Non-Exempt Awards. The following
provisions shall apply to any Vested Non-Exempt Award in connection with a Corporate Transaction: 

(1)    If the Corporate Transaction is also a Section 409A Change in Control then the Acquiring Entity may
not assume, continue or substitute the Vested Non-Exempt Award. Upon the Section 409A Change in Control the settlement of the Vested Non-Exempt Award will
automatically be accelerated and the shares will be immediately issued in respect of the Vested Non-Exempt Award. Alternatively, the Company may instead provide that the Participant will receive a cash
settlement equal to the Fair Market Value of the shares that would otherwise be issued to the Participant upon the Section 409A Change in Control. 

  
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 (2)    If the Corporate Transaction is not also a
Section 409A Change in Control, then the Acquiring Entity must either assume, continue or substitute each Vested Non-Exempt Award. The shares to be issued in respect of the Vested Non-Exempt Award shall be issued to the Participant by the Acquiring Entity on the same schedule that the shares would have been issued to the Participant if the Corporate Transaction had not occurred. In the
Acquiring Entity’s discretion, in lieu of an issuance of shares, the Acquiring Entity may instead substitute a cash payment on each applicable issuance date, equal to the Fair Market Value of the shares that would otherwise be issued to the
Participant on such issuance dates, with the determination of the Fair Market Value of the shares made on the date of the Corporate Transaction. 

(ii)    Unvested Non-Exempt Awards. The following provisions shall
apply to any Unvested Non-Exempt Award unless otherwise determined by the Board pursuant to subsection (e) of this Section. 

(1)    In the event of a Corporate Transaction, the Acquiring Entity shall assume, continue or substitute any
Unvested Non-Exempt Award. Unless otherwise determined by the Board, any Unvested Non-Exempt Award will remain subject to the same vesting and forfeiture restrictions
that were applicable to the Award prior to the Corporate Transaction. The shares to be issued in respect of any Unvested Non-Exempt Award shall be issued to the Participant by the Acquiring Entity on the same
schedule that the shares would have been issued to the Participant if the Corporate Transaction had not occurred. In the Acquiring Entity’s discretion, in lieu of an issuance of shares, the Acquiring Entity may instead substitute a cash payment
on each applicable issuance date, equal to the Fair Market Value of the shares that would otherwise be issued to the Participant on such issuance dates, with the determination of Fair Market Value of the shares made on the date of the Corporate
Transaction. 
 (2)    If the Acquiring Entity will not assume, substitute or continue any Unvested Non-Exempt Award in connection with a Corporate Transaction, then such Award shall automatically terminate and be forfeited upon the Corporate Transaction with no consideration payable to any Participant in respect
of such forfeited Unvested Non-Exempt Award. Notwithstanding the foregoing, to the extent permitted and in compliance with the requirements of Section 409A, the Board may in its discretion determine to
elect to accelerate the vesting and settlement of the Unvested Non-Exempt Award upon the Corporate Transaction, or instead substitute a cash payment equal to the Fair Market Value of such shares that would
otherwise be issued to the Participant, as further provided in subsection (e)(ii) below. In the absence of such discretionary election by the Board, any Unvested Non-Exempt Award shall be forfeited without
payment of any consideration to the affected Participants if the Acquiring Entity will not assume, substitute or continue the Unvested Non-Exempt Awards in connection with the Corporate Transaction. 

(3)    The foregoing treatment shall apply with respect to all Unvested
Non-Exempt Awards upon any Corporate Transaction, and regardless of whether or not such Corporate Transaction is also a Section 409A Change in Control. 

  
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 (d)    Treatment of
Non-Exempt Awards Upon a Corporate Transaction for Non-Employee Directors. The following provisions of this subsection (d) shall apply and shall supersede
anything to the contrary that may be set forth in the Plan with respect to the permitted treatment of a Non-Exempt Director Award in connection with a Corporate Transaction. 

(i)    If the Corporate Transaction is also a Section 409A Change in Control then the Acquiring Entity may not
assume, continue or substitute the Non-Exempt Director Award. Upon the Section 409A Change in Control the vesting and settlement of any Non-Exempt Director Award
will automatically be accelerated and the shares will be immediately issued to the Participant in respect of the Non-Exempt Director Award. Alternatively, the Company may provide that the Participant will
instead receive a cash settlement equal to the Fair Market Value of the shares that would otherwise be issued to the Participant upon the Section 409A Change in Control pursuant to the preceding provision. 

(ii)    If the Corporate Transaction is not also a Section 409A Change in Control, then the Acquiring Entity
must either assume, continue or substitute the Non-Exempt Director Award. Unless otherwise determined by the Board, the Non-Exempt Director Award will remain subject to
the same vesting and forfeiture restrictions that were applicable to the Award prior to the Corporate Transaction. The shares to be issued in respect of the Non-Exempt Director Award shall be issued to the
Participant by the Acquiring Entity on the same schedule that the shares would have been issued to the Participant if the Corporate Transaction had not occurred. In the Acquiring Entity’s discretion, in lieu of an issuance of shares, the
Acquiring Entity may instead substitute a cash payment on each applicable issuance date, equal to the Fair Market Value of the shares that would otherwise be issued to the Participant on such issuance dates, with the determination of Fair Market
Value made on the date of the Corporate Transaction. 
 (e)    If the RSU Award is a Non-Exempt Award, then the provisions in this Section 11(e) shall apply and supersede anything to the contrary that may be set forth in the Plan or the Award Agreement with respect to the permitted treatment of
such Non-Exempt Award: 
 (i)    Any exercise by the Board of discretion
to accelerate the vesting of a Non-Exempt Award shall not result in any acceleration of the scheduled issuance dates for the shares in respect of the Non-Exempt Award
unless earlier issuance of the shares upon the applicable vesting dates would be in compliance with the requirements of Section 409A. 

(ii)    The Company explicitly reserves the right to earlier settle any
Non-Exempt Award to the extent permitted and in compliance with the requirements of Section 409A, including pursuant to any of the exemptions available in Treasury Regulations Section 1.409A-3(j)(4)(ix). 
 (iii)    To the extent the terms of any Non-Exempt Award provide that it will be settled upon a Change in Control or Corporate Transaction, to the extent it is required for compliance with the requirements of Section 409A, the Change in Control or
Corporate Transaction event triggering settlement must also constitute a Section 409A Change in Control. To the extent the terms of a Non-Exempt Award provides that it will be settled upon a termination
of employment or termination of Continuous Service, to the extent it is required for 

  
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compliance with the requirements of Section 409A, the termination event triggering settlement must also constitute a Separation From Service. However, if at the time the shares would
otherwise be issued to a Participant in connection with a “separation from service” such Participant is subject to the distribution limitations contained in Section 409A applicable to “specified employees,” as defined in
Section 409A(a)(2)(B)(i) of the Code, such shares shall not be issued before the date that is six months following the date of the Participant’s Separation From Service, or, if earlier, the date of the Participant’s death that occurs
within such six month period. 
 (iv)    The provisions in this subsection (e) for delivery of the shares in
respect of the settlement of a RSU Award that is a Non-Exempt Award are intended to comply with the requirements of Section 409A so that the delivery of the shares to the Participant in respect of such Non-Exempt Award will not trigger the additional tax imposed under Section 409A, and any ambiguities herein will be so interpreted. 

12.    SEVERABILITY. 

If all or any part of the Plan or any Award Agreement is declared by any court or governmental authority to be unlawful or invalid, such
unlawfulness or invalidity shall not invalidate any portion of the Plan or such Award Agreement not declared to be unlawful or invalid. Any Section of the Plan or any Award Agreement (or part of such a Section) so declared to be unlawful or invalid
shall, if possible, be construed in a manner which will give effect to the terms of such Section or part of a Section to the fullest extent possible while remaining lawful and valid. 

13.    TERMINATION OF THE PLAN. 

The Board may suspend or terminate the Plan at any time. 
 No
Incentive Stock Options may be granted after the tenth anniversary of the earlier of: (i) the Adoption Date, or (ii) the date the Plan is approved by the Company’s stockholders. 

No Awards may be granted under the Plan while the Plan is suspended or after it is terminated. 

  
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 14.    DEFINITIONS. 

As used in the Plan, the following definitions apply to the capitalized terms indicated below: 

(a)    “Acquiring Entity” means the surviving or acquiring corporation (or its parent
company) in connection with a Corporate Transaction. 
 (b)    “Adoption Date” means the
date the Plan is first approved by the Board or Compensation Committee. 

(c)    “Affiliate” means, at the time of determination, any “parent” or
“subsidiary” of the Company as such terms are defined in Rule 405 promulgated under the Securities Act. The Board may determine the time or times at which “parent” or “subsidiary” status is determined within the
foregoing definition. 
 (d)    “Applicable Law” means shall mean any applicable
securities, federal, state, foreign, material local or municipal or other law, statute, constitution, principle of common law, resolution, ordinance, code, edict, decree, rule, listing rule, regulation, judicial decision, ruling or requirement
issued, enacted, adopted, promulgated, implemented or otherwise put into effect by or under the authority of any Governmental Body (including under the authority of any applicable self-regulating organization such as the Nasdaq Stock Market, New
York Stock Exchange, or the Financial Industry Regulatory Authority). 
 (e)    “Award”
means any right to receive Common Stock, cash or other property granted under the Plan (including an Incentive Stock Option, a Nonstatutory Stock Option, a Restricted Stock Award, a RSU Award, a SAR, a Performance Award or any Other Award). 

(f)    “Award Agreement” means a written agreement between the Company and a Participant
evidencing the terms and conditions of an Award. The Award Agreement generally consists of the Grant Notice and the agreement containing the written summary of the general terms and conditions applicable to the Award and which is provided to a
Participant along with the Grant Notice. 
 (g)    “Board” means the Board of Directors
of the Company (or its designee). Any decision or determination made by the Board shall be a decision or determination that is made in the sole discretion of the Board (or its designee), and such decision or determination shall be final and binding
on all Participants. 
 (h)    “Capitalization Adjustment” means any change that
is made in, or other events that occur with respect to, the Common Stock subject to the Plan or subject to any Award after the Effective Date without the receipt of consideration by the Company through merger, consolidation, reorganization,
recapitalization, reincorporation, stock dividend, dividend in property other than cash, large nonrecurring cash dividend, stock split, reverse stock split, liquidating dividend, combination of shares, exchange of shares, change in corporate
structure or any similar equity restructuring transaction, as that term is used in Statement of Financial Accounting Standards Board Accounting Standards Codification Topic 718 (or any successor thereto). Notwithstanding the foregoing, the
conversion of any convertible securities of the Company will not be treated as a Capitalization Adjustment. 

  
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 (i)    “Cause” has the
meaning ascribed to such term in any written agreement between the Participant and the Company defining such term and, in the absence of such agreement, such term means, with respect to a Participant, the occurrence of any of the following events:
(i) such Participant’s attempted commission of, or participation in, a fraud or act of dishonesty against the Company; (ii) such Participant’s intentional, material violation of any contract or agreement between the Participant
and the Company or of any statutory duty owed to the Company; (iii) such Participant’s unauthorized use or disclosure of the Company’s confidential information or trade secrets; or (iv) such Participant’s gross or willful
misconduct. The determination that a termination of the Participant’s Continuous Service is either for Cause or without Cause will be made by the Board with respect to Participants who are executive officers of the Company and by the
Company’s Chief Executive Officer with respect to Participants who are not executive officers of the Company. Any determination by the Company that the Continuous Service of a Participant was terminated with or without Cause for the purposes of
outstanding Awards held by such Participant will have no effect upon any determination of the rights or obligations of the Company or such Participant for any other purpose. 

(j)    “Change in Control” or “Change of Control” means the
occurrence, in a single transaction or in a series of related transactions, of any one or more of the following events; provided, however, to the extent necessary to avoid adverse personal income tax consequences to the Participant in connection
with an Award, also constitutes a Section 409A Change in Control: 
 (i)    any Exchange Act Person becomes
the Owner, directly or indirectly, of securities of the Company representing more than 50% of the combined voting power of the Company’s then outstanding securities other than by virtue of a merger, consolidation or similar transaction.
Notwithstanding the foregoing, a Change in Control shall not be deemed to occur (A) on account of the acquisition of securities of the Company directly from the Company, (B) on account of the acquisition of securities of the Company by an
investor, any affiliate thereof or any other Exchange Act Person that acquires the Company’s securities in a transaction or series of related transactions the primary purpose of which is to obtain financing for the Company through the issuance
of equity securities, or (C) solely because the level of Ownership held by any Exchange Act Person (the “Subject Person”) exceeds the designated percentage threshold of the outstanding voting securities as a result of a
repurchase or other acquisition of voting securities by the Company reducing the number of shares outstanding, provided that if a Change in Control would occur (but for the operation of this sentence) as a result of the acquisition of voting
securities by the Company, and after such share acquisition, the Subject Person becomes the Owner of any additional voting securities that, assuming the repurchase or other acquisition had not occurred, increases the percentage of the then
outstanding voting securities Owned by the Subject Person over the designated percentage threshold, then a Change in Control shall be deemed to occur; 

(ii)    there is consummated a merger, consolidation or similar transaction involving (directly or indirectly) the
Company and, immediately after the consummation of such merger, consolidation or similar transaction, the stockholders of the Company immediately prior thereto do not Own, directly or indirectly, either (A) outstanding voting securities


  
 24. 













 
representing more than 50% of the combined outstanding voting power of the surviving Entity in such merger, consolidation or similar transaction or (B) more than 50% of the combined
outstanding voting power of the parent of the surviving Entity in such merger, consolidation or similar transaction, in each case in substantially the same proportions as their Ownership of the outstanding voting securities of the Company
immediately prior to such transaction; 
 (iii)    there is consummated a sale, lease, exclusive license or other
disposition of all or substantially all of the consolidated assets of the Company and its Subsidiaries, other than a sale, lease, license or other disposition of all or substantially all of the consolidated assets of the Company and its Subsidiaries
to an Entity, more than 50% of the combined voting power of the voting securities of which are Owned by stockholders of the Company in substantially the same proportions as their Ownership of the outstanding voting securities of the Company
immediately prior to such sale, lease, license or other disposition; or 
 (iv)    individuals who, on the date
the Plan is adopted by the Board, are members of the Board (the “Incumbent Board”) cease for any reason to constitute at least a majority of the members of the Board; provided, however, that if the appointment or election (or
nomination for election) of any new Board member was approved or recommended by a majority vote of the members of the Incumbent Board then still in office, such new member shall, for purposes of this Plan, be considered as a member of the Incumbent
Board. 
 Notwithstanding the foregoing or any other provision of this Plan, (A) the term Change in Control shall not include a sale of
assets, merger or other transaction effected exclusively for the purpose of changing the domicile of the Company, and (B) the definition of Change in Control (or any analogous term) in an individual written agreement between the Company or any
Affiliate and the Participant shall supersede the foregoing definition with respect to Awards subject to such agreement; provided, however, that if no definition of Change in Control or any analogous term is set forth in such an individual written
agreement, the foregoing definition shall apply. 
 (k)    “Code” means the Internal
Revenue Code of 1986, as amended, including any applicable regulations and guidance thereunder. 

(l)    “Committee” means the Compensation Committee and any other committee of Directors to
whom authority has been delegated by the Board or Compensation Committee in accordance with the Plan. 

(m)    “Common Stock” means the common stock of the Company. 

(n)    “Company” means Keros Therapeutics, Inc., a Delaware corporation. 

(o)    “Compensation Committee” means the Compensation Committee of the Board. 

(p)    “Consultant” means any person, including an advisor, who is (i) engaged by the
Company or an Affiliate to render consulting or advisory services and is compensated for such services, or (ii) serving as a member of the board of directors of an Affiliate and is compensated for such services. However, service solely as a
Director, or payment of a fee for such service, will not cause a Director to be considered a “Consultant” for purposes of the Plan. 

  
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Notwithstanding the foregoing, a person is treated as a Consultant under this Plan only if a Form S-8 Registration Statement under the Securities Act is
available to register either the offer or the sale of the Company’s securities to such person. 

(q)    “Continuous Service” means that the Participant’s service with the Company or
an Affiliate, whether as an Employee, Director or Consultant, is not interrupted or terminated. A change in the capacity in which the Participant renders service to the Company or an Affiliate as an Employee, Director or Consultant or a change in
the Entity for which the Participant renders such service, provided that there is no interruption or termination of the Participant’s service with the Company or an Affiliate, will not terminate a Participant’s Continuous Service;
provided, however, that if the Entity for which a Participant is rendering services ceases to qualify as an Affiliate, as determined by the Board, such Participant’s Continuous Service will be considered to have terminated on the
date such Entity ceases to qualify as an Affiliate. For example, a change in status from an Employee of the Company to a Consultant of an Affiliate or to a Director will not constitute an interruption of Continuous Service. To the extent permitted
by law, the Board or the chief executive officer of the Company, in that party’s sole discretion, may determine whether Continuous Service will be considered interrupted in the case of (i) any leave of absence approved by the Board or
chief executive officer, including sick leave, military leave or any other personal leave, or (ii) transfers between the Company, an Affiliate, or their successors. Notwithstanding the foregoing, a leave of absence will be treated as Continuous
Service for purposes of vesting in an Award only to such extent as may be provided in the Company’s leave of absence policy, in the written terms of any leave of absence agreement or policy applicable to the Participant, or as otherwise
required by law. In addition, to the extent required for exemption from or compliance with Section 409A, the determination of whether there has been a termination of Continuous Service will be made, and such term will be construed, in a manner
that is consistent with the definition of “separation from service” as defined under Treasury Regulation Section 1.409A-1(h) (without regard to any alternative definition thereunder). 

(r)    “Corporate Transaction” means the consummation, in a single transaction or in a
series of related transactions, of any one or more of the following events: 
 (i)    a sale or other
disposition of all or substantially all, as determined by the Board, of the consolidated assets of the Company and its Subsidiaries; 

(ii)    a sale or other disposition of at least 50% of the outstanding securities of the Company; 

(iii)    a merger, consolidation or similar transaction following which the Company is not the surviving
corporation; or 
 (iv)    a merger, consolidation or similar transaction following which the Company is the
surviving corporation but the shares of Common Stock outstanding immediately preceding the merger, consolidation or similar transaction are converted or exchanged by virtue of the merger, consolidation or similar transaction into other property,
whether in the form of securities, cash or otherwise. 

  
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 (s)    “Director” means a member of the
Board. 
 (t)    “determine” or “determined”
means as determined by the Board or the Committee (or its designee) in its sole discretion. 

(u)    “Disability” means, with respect to a Participant, such Participant is unable to
engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12
months, as provided in Section 22(e)(3) of the Code, and will be determined by the Board on the basis of such medical evidence as the Board deems warranted under the circumstances. 

(v)    “Effective Date” means immediately prior to the IPO Date, provided this Plan is
approved by the Company’s stockholders prior to the IPO Date. 
 (w)    “Employee”
means any person employed by the Company or an Affiliate. However, service solely as a Director, or payment of a fee for such services, will not cause a Director to be considered an “Employee” for purposes of the Plan. 

(x)    “Employer” means the Company or the Affiliate of the Company that employs the
Participant. 
 (y)    “Entity” means a corporation, partnership, limited liability
company or other entity. 
 (z)    “Exchange Act” means the Securities Exchange Act of
1934, as amended, and the rules and regulations promulgated thereunder. 
 (aa)    “Exchange Act
Person” means any natural person, Entity or “group” (within the meaning of Section 13(d) or 14(d) of the Exchange Act), except that “Exchange Act Person” will not include (i) the Company or
any Subsidiary of the Company, (ii) any employee benefit plan of the Company or any Subsidiary of the Company or any trustee or other fiduciary holding securities under an employee benefit plan of the Company or any Subsidiary of the Company,
(iii) an underwriter temporarily holding securities pursuant to a registered public offering of such securities, (iv) an Entity Owned, directly or indirectly, by the stockholders of the Company in substantially the same proportions as
their Ownership of stock of the Company; or (v) any natural person, Entity or “group” (within the meaning of Section 13(d) or 14(d) of the Exchange Act) that, as of the Effective Date, is the Owner, directly or indirectly, of
securities of the Company representing more than 50% of the combined voting power of the Company’s then outstanding securities. 

(bb)    “Fair Market Value” means, as of any date, unless otherwise determined by the
Board, the value of the Common Stock (as determined on a per share or aggregate basis, as applicable) determined as follows: 

(i)    If the Common Stock is listed on any established stock exchange or traded on any established market, the
Fair Market Value will be the closing sales price for such stock as quoted on such exchange or market (or the exchange or market with the greatest volume of trading in the Common Stock) on the date of determination, as reported in a source the Board
deems reliable. 

  
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 (ii)    If there is no closing sales price for the Common Stock
on the date of determination, then the Fair Market Value will be the closing selling price on the last preceding date for which such quotation exists. 

(iii)    In the absence of such markets for the Common Stock, or if otherwise determined by the Board, the Fair
Market Value will be determined by the Board in good faith and in a manner that complies with Sections 409A and 422 of the Code. 

(cc)    “Governmental Body” means any: (a) nation, state,
commonwealth, province, territory, county, municipality, district or other jurisdiction of any nature; (b) federal, state, local, municipal, foreign or other government; (c) governmental or regulatory body, or quasi-governmental body of
any nature (including any governmental division, department, administrative agency or bureau, commission, authority, instrumentality, official, ministry, fund, foundation, center, organization, unit, body or Entity and any court or other tribunal,
and for the avoidance of doubt, any Tax authority) or other body exercising similar powers or authority; or (d) self-regulatory organization (including the Nasdaq Stock Market, New York Stock Exchange, and the Financial Industry Regulatory
Authority). 
 (dd)    “Grant Notice” means the notice provided to a Participant that he
or she has been granted an Award under the Plan and which includes the name of the Participant, the type of Award, the date of grant of the Award, number of shares of Common Stock subject to the Award or potential cash payment right, (if any), the
vesting schedule for the Award (if any) and other key terms applicable to the Award. 

(ee)    “Incentive Stock Option” means an option granted pursuant to Section 4 of the
Plan that is intended to be, and qualifies as, an “incentive stock option” within the meaning of Section 422 of the Code. 

(ff)    “IPO Date” means the date of the underwriting agreement between the Company and the
underwriter(s) managing the initial public offering of the Common Stock, pursuant to which the Common Stock is priced for the initial public offering. 

(gg)    “Materially Impair” means any amendment to the terms of the Award
that materially adversely affects the Participant’s rights under the Award. A Participant’s rights under an Award will not be deemed to have been Materially Impaired by any such amendment if the Board, in its sole discretion, determines
that the amendment, taken as a whole, does not materially impair the Participant’s rights. For example, the following types of amendments to the terms of an Award do not Materially Impair the Participant’s rights under the Award:
(i) imposition of reasonable restrictions on the minimum number of shares subject to an Option that may be exercised; (ii) to maintain the qualified status of the Award as an Incentive Stock Option under Section 422 of the Code;
(iii) to change the terms of an Incentive Stock Option in a manner that disqualifies, impairs or otherwise affects the qualified status of the Award as an Incentive Stock Option under Section 422 of the Code; (iv) to clarify the
manner of exemption from, or to bring the Award into compliance with or qualify it for an exemption from, Section 409A; or (v) to comply with other Applicable Laws. 

  
 28. 














(hh)    “Non-Employee Director” means a
Director who either (i) is not a current employee or officer of the Company or an Affiliate, does not receive compensation, either directly or indirectly, from the Company or an Affiliate for services rendered as a consultant or in any capacity
other than as a Director (except for an amount as to which disclosure would not be required under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act (“Regulation S-K”)), does not possess an interest in any other transaction for which disclosure would be required under Item 404(a) of Regulation S-K, and is not engaged in a
business relationship for which disclosure would be required pursuant to Item 404(b) of Regulation S-K; or (ii) is otherwise considered a “non-employee
director” for purposes of Rule 16b-3. 
 (ii)    “Non-Exempt Award” means any Award that is subject to, and not exempt from, Section 409A, including as the result of (i) a deferral of the issuance of the shares subject to the
Award which is elected by the Participant or imposed by the Company, (ii) the terms of any Non-Exempt Severance Agreement. 

(jj)    “Non-Exempt Director Award” means a Non-Exempt Award granted to a Participant who was a Director but not an Employee on the applicable grant date. 

(kk)    “Non-Exempt Severance Arrangement” means a
severance arrangement or other agreement between the Participant and the Company that provides for acceleration of vesting of an Award and issuance of the shares in respect of such Award upon the Participant’s termination of employment or
separation from service (as such term is defined in Section 409A(a)(2)(A)(i) of the Code (and without regard to any alternative definition thereunder) (“Separation from Service”) and such severance benefit does not
satisfy the requirements for an exemption from application of Section 409A provided under Treasury Regulations Section 1.409A-1(b)(4), 1.409A-1(b)(9) or
otherwise. 
 (ll)    “Nonstatutory Stock Option” means any option granted pursuant to
Section 4 of the Plan that does not qualify as an Incentive Stock Option. 

(mm)    “Officer” means a person who is an officer of the Company within the meaning of
Section 16 of the Exchange Act. 
 (nn)    “Option” means an Incentive Stock Option
or a Nonstatutory Stock Option to purchase shares of Common Stock granted pursuant to the Plan. 

(oo)    “Option Agreement” means a written agreement between the Company and the
Optionholder evidencing the terms and conditions of the Option grant. The Option Agreement includes the Grant Notice for the Option and the agreement containing the written summary of the general terms and conditions applicable to the Option and
which is provided to a Participant along with the Grant Notice. Each Option Agreement will be subject to the terms and conditions of the Plan. 

(pp)    “Optionholder” means a person to whom an Option is granted pursuant to the Plan or,
if applicable, such other person who holds an outstanding Option. 

  
 29. 













 (qq)    “Other Award” means an award
based in whole or in part by reference to the Common Stock which is granted pursuant to the terms and conditions of Section 5(c). 

(rr)    “Other Award Agreement” means a written agreement between the Company
and a holder of an Other Award evidencing the terms and conditions of an Other Award grant. Each Other Award Agreement will be subject to the terms and conditions of the Plan. 

(ss)    “Own,” “Owned,”
“Owner,” “Ownership” means that a person or Entity will be deemed to “Own,” to have “Owned,” to be the “Owner” of, or to have acquired
“Ownership” of securities if such person or Entity, directly or indirectly, through any contract, arrangement, understanding, relationship or otherwise, has or shares voting power, which includes the power to vote or to direct the voting,
with respect to such securities. 
 (tt)    “Participant” means an Employee, Director or
Consultant to whom an Award is granted pursuant to the Plan or, if applicable, such other person who holds an outstanding Award. 

(uu)    “Performance Award” means an Award that may vest or may be exercised or a cash
award that may vest or become earned and paid contingent upon the attainment during a Performance Period of certain Performance Goals and which is granted under the terms and conditions of Section 5(b) pursuant to such terms as are approved by
the Board. In addition, to the extent permitted by Applicable Law and set forth in the applicable Award Agreement, the Board may determine that cash or other property may be used in payment of Performance Awards. Performance Awards that are settled
in cash or other property are not required to be valued in whole or in part by reference to, or otherwise based on, the Common Stock. 

(vv)    “Performance Criteria” means the one or more criteria that the Board will select
for purposes of establishing the Performance Goals for a Performance Period. The Performance Criteria that will be used to establish such Performance Goals may be based on any measure of performance selected by the Board. 

(ww)    “Performance Goals” means, for a Performance Period, the one or more goals
established by the Board for the Performance Period based upon the Performance Criteria. Performance Goals may be based on a Company-wide basis, with respect to one or more business units, divisions, Affiliates, or business segments, and in either
absolute terms or relative to the performance of one or more comparable companies or the performance of one or more relevant indices. Unless specified otherwise by the Board (i) in the Award Agreement at the time the Award is granted or
(ii) in such other document setting forth the Performance Goals at the time the Performance Goals are established, the Board will appropriately make adjustments in the method of calculating the attainment of Performance Goals for a Performance
Period as follows: (1) to exclude restructuring and/or other nonrecurring charges; (2) to exclude exchange rate effects; (3) to exclude the effects of changes to generally accepted accounting principles; (4) to exclude the
effects of any statutory adjustments to corporate tax rates; (5) to exclude the effects of items that are “unusual” in nature or occur “infrequently” as determined under generally accepted accounting principles; (6) to
exclude the dilutive effects of acquisitions or joint ventures; (7) to assume that any business divested by the Company achieved performance objectives at targeted levels during the balance of a Performance Period following such


  
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divestiture; (8) to exclude the effect of any change in the outstanding shares of common stock of the Company by reason of any stock dividend or split, stock repurchase, reorganization,
recapitalization, merger, consolidation, spin-off, combination or exchange of shares or other similar corporate change, or any distributions to common stockholders other than regular cash dividends;
(9) to exclude the effects of stock based compensation and the award of bonuses under the Company’s bonus plans; (10) to exclude costs incurred in connection with potential acquisitions or divestitures that are required to expense
under generally accepted accounting principles; and (11) to exclude the goodwill and intangible asset impairment charges that are required to be recorded under generally accepted accounting principles. In addition, the Board retains the
discretion to reduce or eliminate the compensation or economic benefit due upon attainment of Performance Goals and to define the manner of calculating the Performance Criteria it selects to use for such Performance Period. Partial achievement of
the specified criteria may result in the payment or vesting corresponding to the degree of achievement as specified in the Award Agreement or the written terms of a Performance Cash Award. 

(xx)    “Performance Period” means the period of time selected by the Board over which the
attainment of one or more Performance Goals will be measured for the purpose of determining a Participant’s right to vesting or exercise of an Award. Performance Periods may be of varying and overlapping duration, at the sole discretion of the
Board. 
 (yy)    “Plan” means this Keros Therapeutics, Inc. 2020 Equity Incentive Plan,
as amended from time to time. 
 (zz)    “Plan Administrator” means the person, persons,
and/or third-party administrator designated by the Company to administer the day to day operations of the Plan and the Company’s other equity incentive programs. 

(aaa)    “Post-Termination Exercise Period” means the period following termination of a
Participant’s Continuous Service within which an Option or SAR is exercisable, as specified in Section 4(h). 

(bbb)    “Prior Plan’s Available Reserve” means the number of shares available for the
grant of new awards under the Prior Plan as of the Effective Date. 
 (ccc)    “Prior
Plan” means the Keros Therapeutics, Inc. 2017 Stock Incentive Plan. 

(ddd)    “Prospectus” means the document containing the Plan information specified in
Section 10(a) of the Securities Act. 
 (eee)    “Restricted Stock Award” or
“RSA” means an Award of shares of Common Stock which is granted pursuant to the terms and conditions of Section 5(a). 

(fff)    “Restricted Stock Award Agreement” means a written agreement between the Company
and a holder of a Restricted Stock Award evidencing the terms and conditions of a Restricted Stock Award grant. The Restricted Stock Award Agreement includes the Grant Notice for the Restricted Stock Award and the agreement containing the written
summary of the general terms and conditions applicable to the Restricted Stock Award and which is provided to a Participant along with the Grant Notice. Each Restricted Stock Award Agreement will be subject to the terms and conditions of the Plan.


  
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 (ggg)    “Returning Shares” means shares
subject to outstanding stock awards granted under the Prior Plan and that following the Effective Date: (A) are not issued because such stock award or any portion thereof expires or otherwise terminates without all of the shares covered by
such stock award having been issued; (B) are not issued because such stock award or any portion thereof is settled in cash; (C) are forfeited back to or repurchased by the Company because of the failure to meet a contingency or
condition required for the vesting of such shares; (D) are withheld or reacquired to satisfy the exercise, strike or purchase price; or (E) are withheld or reacquired to satisfy a tax withholding obligation. 

(hhh)    “RSU Award” or “RSU” means an Award of
restricted stock units representing the right to receive an issuance of shares of Common Stock which is granted pursuant to the terms and conditions of Section 5(a). 

(iii)    “RSU Award Agreement” means a written agreement between the Company
and a holder of a RSU Award evidencing the terms and conditions of a RSU Award grant. The RSU Award Agreement includes the Grant Notice for the RSU Award and the agreement containing the written summary of the general terms and conditions applicable
to the RSU Award and which is provided to a Participant along with the Grant Notice. Each RSU Award Agreement will be subject to the terms and conditions of the Plan. 

(jjj)    “Rule 16b-3” means Rule 16b-3 promulgated under the Exchange Act or any successor to Rule 16b-3, as in effect from time to time. 

(kkk)    “Rule 405” means Rule 405 promulgated under the Securities Act. 

(lll)    “Section 409A” means Section 409A of the
Code and the regulations and other guidance thereunder. 

(mmm)    “Section 409A Change in Control” means a change
in the ownership or effective control of the Company, or in the ownership of a substantial portion of the Company’s assets, as provided in Section 409A(a)(2)(A)(v) of the Code and Treasury Regulations
Section 1.409A-3(i)(5) (without regard to any alternative definition thereunder). 

(nnn)    “Securities Act” means the Securities Act of 1933, as amended. 

(ooo)    “Share Reserve” means the number of shares available for issuance under the Plan
as set forth in Section 2(a). 
 (ppp)    “Stock Appreciation Right” or
“SAR” means a right to receive the appreciation on Common Stock that is granted pursuant to the terms and conditions of Section 4. 

(qqq)    “SAR Agreement” means a written agreement between the Company and a holder of a
SAR evidencing the terms and conditions of a SAR grant. The SAR Agreement includes the Grant Notice for the SAR and the agreement containing the written summary of the general terms and conditions applicable to the SAR and which is provided to a
Participant along with the Grant Notice. Each SAR Agreement will be subject to the terms and conditions of the Plan. 

  
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 (rrr)    “Subsidiary” means, with respect
to the Company, (i) any corporation of which more than 50% of the outstanding capital stock having ordinary voting power to elect a majority of the board of directors of such corporation (irrespective of whether, at the time, stock of any other
class or classes of such corporation will have or might have voting power by reason of the happening of any contingency) is at the time, directly or indirectly, Owned by the Company, and (ii) any partnership, limited liability company or other
entity in which the Company has a direct or indirect interest (whether in the form of voting or participation in profits or capital contribution) of more than 50%. 

(sss)    “Ten Percent Stockholder” means a person who Owns (or is deemed to Own pursuant to
Section 424(d) of the Code) stock possessing more than 10% of the total combined voting power of all classes of stock of the Company or any Affiliate. 

(ttt)    “Trading Policy” means the Company’s policy permitting certain individuals to
sell Company shares only during certain “window” periods and/or otherwise restricts the ability of certain individuals to transfer or encumber Company shares, as in effect from time to time. 

(uuu)    “Unvested Non-Exempt Award” means the
portion of any Non-Exempt Award that had not vested in accordance with its terms upon or prior to the date of any Corporate Transaction. 

(vvv)    “Vested Non-Exempt Award” means the
portion of any Non-Exempt Award that had vested in accordance with its terms upon or prior to the date of a Corporate Transaction. 

  
 33.