EX-10.4B





 Exhibit 10.4(b) 

BIOMEA FUSION, INC. 

2021 INCENTIVE AWARD PLAN 

STOCK OPTION GRANT NOTICE 

Biomea Fusion, Inc., a Delaware corporation, (the “Company”), pursuant to its 2021 Incentive Award Plan, as may be
amended from time to time (the “Plan”), hereby grants to the holder listed below (“Participant”), an option to purchase the number of shares of the Company’s Common Stock (the
“Shares”), set forth below (the “Option”). This Option is subject to all of the terms and conditions set forth herein, as well as in the Plan and the Stock Option Agreement attached hereto as
Exhibit A (the “Stock Option Agreement”), each of which are incorporated herein by reference. Unless otherwise defined herein, the terms defined in the Plan shall have the same defined meanings in this Grant Notice and
the Stock Option Agreement. 
  

			
	Participant:	  	[____________]
		
	Grant Date:	  	[____________]
		
	Vesting Commencement Date:	  	[____________]
		
	Exercise Price per Share:	  	$[___________]
		
	Total Exercise Price:	  	$[____________]
		
	Total Number of Shares Subject to the Option:	  	[____________]
		
	Expiration Date:	  	[____________]
		
	Vesting Schedule:	  	[____________]

 Type of Option:
            ☐    Incentive Stock
Option                    ☐    Nonqualified Stock Option 

By his or her signature and the Company’s signature below, Participant agrees to be bound by the terms and conditions of the Plan, the
Stock Option Agreement and this Grant Notice. Participant has reviewed the Plan, the Stock Option Agreement and this Grant Notice in their entirety, has had an opportunity to obtain the advice of counsel prior to executing this Grant Notice and
fully understands all provisions of the Plan, the Stock Option Agreement and this Grant Notice. Participant hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Administrator upon any questions arising
under the Plan, the Stock Option Agreement or this Grant Notice. 
  

									
	BIOMEA FUSION, INC.:	 		 	PARTICIPANT:
					
	By:	 	  
	 		 	By:	 	          

	Print Name:	 	  
	 		 	Print Name:	 	              

	Title:	 	  
	 		 		 	
	Address:	 	  
	 		 	Address:	 	              

		 	  
	 		 		 	
                 














 EXHIBIT A 

TO STOCK OPTION GRANT NOTICE 

STOCK OPTION AGREEMENT 

Pursuant to the Stock Option Grant Notice (the “Grant Notice”) to which this Stock Option Agreement (this
“Agreement”) is attached, Biomea Fusion, Inc., a Delaware corporation (the “Company”), has granted to Participant an Option under the Company’s 2021 Incentive Award Plan, as may be amended from
time to time (the “Plan”), to purchase the number of Shares indicated in the Grant Notice. 
 ARTICLE 1. 

GENERAL 
 1.1 Defined
Terms. Capitalized terms not specifically defined herein shall have the meanings specified in the Plan and the Grant Notice. 
 1.2
Incorporation of Terms of Plan. The Option is subject to the terms and conditions of the Plan which are incorporated herein by reference. In the event of any inconsistency between the Plan and this Agreement, the terms of the Plan shall
control. 
 ARTICLE 2. 

GRANT OF OPTION 
 2.1
Grant of Option. In consideration of Participant’s past and/or continued employment with or service to the Company or any Subsidiary and for other good and valuable consideration, effective as of the Grant Date set forth in the Grant
Notice (the “Grant Date”), the Company irrevocably grants to Participant the Option to purchase any part or all of an aggregate of the number of Shares set forth in the Grant Notice, upon the terms and conditions set forth in
the Plan and this Agreement, subject to adjustments as provided in Article IX of the Plan. Unless designated as a Nonqualified Stock Option in the Grant Notice, the Option shall be an Incentive Stock Option to the maximum extent permitted by law.

 2.2 Exercise Price. The exercise price of the Shares subject to the Option shall be as set forth in the Grant Notice, without
commission or other charge; provided, however, that the exercise price per share of the Shares subject to the Option shall not be less than 100% of the Fair Market Value of a Share on the Grant Date. Notwithstanding the foregoing, if
this Option is designated as an Incentive Stock Option and Participant is a Greater Than 10% Stockholder as of the Grant Date, the exercise price per share of the Shares subject to the Option shall not be less than 110% of the Fair Market Value of a
Share on the Grant Date. 
 2.3 Consideration to the Company. In consideration of the grant of the Option by the Company, Participant
agrees to render faithful and efficient services to the Company or any Subsidiary. Nothing in the Plan or this Agreement shall confer upon Participant any right to continue in the employ or service of the Company or any Subsidiary or shall interfere
with or restrict in any way the rights of the Company and its Subsidiaries, which rights are hereby expressly reserved, to discharge or terminate the services of Participant at any time for any reason whatsoever, with or without cause, except to the
extent expressly provided otherwise in a written agreement between the Company or a Subsidiary and Participant. 

  
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 ARTICLE 3. 

PERIOD OF EXERCISABILITY 

3.1 Commencement of Exercisability. 

(a) Subject to Sections 3.2, 3.3, 5.11 and 5.17 hereof, the Option shall become vested and exercisable in such amounts and at such times as are
set forth in the Grant Notice. 
 (b) No portion of the Option which has not become vested and exercisable at the date of Participant’s
Termination of Service shall thereafter become vested and exercisable, except as may be otherwise provided by the Administrator or as set forth in a written agreement between the Company and Participant. 

(c) Notwithstanding Section 3.1(a) hereof and the Grant Notice, but subject to Section 3.1(b) hereof, in the event of a Change in
Control the Option shall be treated pursuant to Sections 9.2 and 9.3 of the Plan. 
 3.2 Duration of Exercisability. The installments
provided for in the vesting schedule set forth in the Grant Notice are cumulative. Each such installment which becomes vested and exercisable pursuant to the vesting schedule set forth in the Grant Notice shall remain vested and exercisable until it
becomes unexercisable under Section 3.3 hereof. 
 3.3 Expiration of Option. The Option may not be exercised to any extent by
anyone after the first to occur of the following events: 
 (a) The Expiration Date set forth in the Grant Notice, which shall in no event be
more than ten years from the Grant Date; 
 (b) If this Option is designated as an Incentive Stock Option and Participant, at the time the
Option was granted, was a Greater Than 10% Stockholder, the expiration of five years from the Grant Date; 
 (c) The expiration of three
months from the date of Participant’s Termination of Service, unless such termination occurs by reason of Participant’s death or Disability or Cause; 

(d) The expiration of one year from the date of Participant’s Termination of Service by reason of Participant’s death or Disability;
or 
 (e) Participant’s termination of Service for Cause. 

3.4 Special Tax Consequences. Participant acknowledges that, to the extent that the aggregate Fair Market Value (determined as of the
time the Option is granted) of all Shares with respect to which Incentive Stock Options, including the Option (if applicable), are exercisable for the first time by Participant in any calendar year exceeds $100,000, the Option and such other options
shall be Nonqualified Stock Options to the extent necessary to comply with the limitations imposed by Section 422(d) of the Code. Participant further acknowledges that the rule set forth in the preceding sentence shall be applied by taking the
Option and other “incentive stock options” into account in the order in which they were granted, as determined under Section 422(d) of the Code and the Treasury Regulations thereunder. Participant also acknowledges that an Incentive
Stock Option exercised more than three months after Participant’s Termination of Employment, other than by reason of death or Disability, will be taxed as a Nonqualified Stock Option. 

  
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 3.5 Tax Indemnity. 

(a) Participant agrees to indemnify and keep indemnified the Company, any Subsidiary and Participant’s employing company, if different,
from and against any liability for or obligation to pay any Tax Related Items that is attributable to (1) the grant or exercise of, or any benefit derived by Participant from, the Option, (2) the acquisition by Participant of the Shares on
exercise of the Option or (3) the disposal of any Shares. 
 (b) The Option cannot be exercised until Participant has made such
arrangements as the Company may require for the satisfaction of any Tax Related Items that may arise in connection with the exercise of the Option or the acquisition of the Shares by Participant. The Company shall not be required to issue, allot or
transfer Shares until Participant has satisfied this obligation. 
 (c) Participant hereby acknowledges that the Company (i) makes no
representations or undertakings regarding the treatment of any Tax Related Items in connection with any aspect of the Option and (ii) does not commit to and is under no obligation to structure the terms of the grant or any aspect of any Award,
including the Option, to reduce or eliminate Participant’s liability for Tax Related Items or achieve any particular tax result. Furthermore, if Participant becomes subject to tax in more than one jurisdiction between the date of grant of an
Award, including the Option, and the date of any relevant taxable event, Participant acknowledges that the Company may be required to withhold or account for Tax Related Items in more than one jurisdiction. 

ARTICLE 4. 
 EXERCISE OF
OPTION 
 4.1 Person Eligible to Exercise. Except as provided in Section 5.3 hereof, during the lifetime of Participant,
only Participant may exercise the Option or any portion thereof, unless it has been disposed of pursuant to a DRO. After the death of Participant, any exercisable portion of the Option may, prior to the time when the Option becomes unexercisable
under Section 3.3 hereof, be exercised by the deceased Participant’s personal representative or by any person empowered to do so under the deceased Participant’s will or under the then applicable laws of descent and distribution. 

4.2 Partial Exercise. Any exercisable portion of the Option or the entire Option, if then wholly exercisable, may be exercised in whole
or in part at any time prior to the time when the Option or portion thereof becomes unexercisable under Section 3.3 hereof. However, the Option shall not be exercisable with respect to fractional Shares. 

4.3 Manner of Exercise. The Option, or any exercisable portion thereof, may be exercised solely by delivery to the Secretary of the
Company (or any third party administrator or other person or entity designated by the Company; for the avoidance of doubt, delivery shall include electronic delivery), during regular business hours, of all of the following prior to the time when the
Option or such portion thereof becomes unexercisable under Section 3.3 hereof: 
 (a) An exercise notice in a form specified by the
Administrator, stating that the Option or portion thereof is thereby exercised, such notice complying with all applicable rules established by the Administrator. The notice shall be signed by Participant or other person then entitled to exercise the
Option or such portion of the Option; 

  
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 (b) The receipt by the Company of full payment for the Shares with respect to which the
Option or portion thereof is exercised, including payment of any applicable Tax Related Items, which shall be made by deduction from other compensation payable Participant or in such other form of consideration permitted under Section 4.4
hereof that is acceptable to the Company; 
 (c) Any other written representations or documents as may be required in the
Administrator’s sole discretion to evidence compliance with the Securities Act, the Exchange Act or any other applicable law, rule or regulation; and 

(d) In the event the Option or portion thereof shall be exercised pursuant to Section 4.1 hereof by any person or persons other than
Participant, appropriate proof of the right of such person or persons to exercise the Option. 
 Notwithstanding any of the foregoing, the Company shall
have the right to specify all conditions of the manner of exercise, which conditions may vary by country and which may be subject to change from time to time. 

4.4 Method of Payment. Payment of the exercise price shall be by any of the following, or a combination thereof, at the election of
Participant: 
 (a) Cash or check; 

(b) With the consent of the Administrator, surrender of Shares (including, without limitation, Shares otherwise issuable upon exercise of the
Option) held for such period of time as may be required by the Administrator in order to avoid adverse accounting consequences and having a Fair Market Value on the date of delivery equal to the aggregate exercise price of the Option or exercised
portion thereof; or 
 (c) Other legal consideration acceptable to the Administrator (including, without limitation, through the delivery of
a notice that Participant has placed a market sell order with a broker with respect to Shares then issuable upon exercise of the Option, and that the broker has been directed to pay a sufficient portion of the net proceeds of the sale to the Company
in satisfaction of the Option exercise price; provided that payment of such proceeds is then made to the Company at such time as may be required by the Company, but in any event not later than the settlement of such sale). 

4.5 Conditions to Issuance of Shares. The Shares deliverable upon the exercise of the Option, or any portion thereof, may be either
previously authorized but unissued Shares or issued Shares which have then been reacquired by the Company. Such Shares shall be fully paid and nonassessable. The Company shall not be required to issue or deliver any Shares purchased upon the
exercise of the Option or portion thereof prior to fulfillment of all of the conditions in Section 10.7 of the Plan and following conditions: 

(a) The admission of such Shares to listing on all stock exchanges on which such Shares are then listed; 

(b) The completion of any registration or other qualification of such Shares under any state or federal law or under rulings or regulations of
the Securities and Exchange Commission or of any other governmental regulatory body, which the Administrator shall, in its absolute discretion, deem necessary or advisable; 

  
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 (c) The obtaining of any approval or other clearance from any state or federal governmental
agency which the Administrator shall, in its absolute discretion, determine to be necessary or advisable; 
 (d) The receipt by the Company
of full payment for such Shares, including payment of any applicable Tax Related Items, which may be in one or more of the forms of consideration permitted under Section 4.4 hereof; and 

(e) The lapse of such reasonable period of time following the exercise of the Option as the Administrator may from time to time establish for
reasons of administrative convenience. 
 4.6 Participant’s Representations. If the Shares issuable hereunder have not been
registered under the Securities Act or any applicable state laws on an effective registration statement at the time of exercise, Participant shall, if required by the Company, concurrently with such exercise, make such written representations as are
deemed necessary or appropriate by the Company or its counsel. 
 4.7 Rights as Stockholder. The holder of the Option shall not be,
nor have any of the rights or privileges of, a stockholder of the Company, including, without limitation, voting rights and rights to dividends, in respect of any Shares purchasable upon the exercise of any part of the Option unless and until such
Shares shall have been issued by the Company and held of record by such holder (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company). No adjustment will be made for a dividend or
other right for which the record date is prior to the date the Shares are issued, except as provided in Article IX of the Plan. 
 ARTICLE
5. 
 OTHER PROVISIONS 

5.1 Administration. The Administrator shall have the power to interpret the Plan and this Agreement and to adopt such rules for the
administration, interpretation and application of the Plan as are consistent therewith and to interpret, amend or revoke any such rules. All actions taken and all interpretations and determinations made by the Administrator in good faith shall be
final and binding upon Participant, the Company and all other interested persons. No member of the Committee or the Board shall be personally liable for any action, determination or interpretation made in good faith with respect to the Plan, this
Agreement or the Option. 
 5.2 Whole Shares. The Option may only be exercised for whole Shares. 

5.3 Transferability. 
 (a)
Subject to Section 4.1 hereof, the Option may not be sold, pledged, assigned or transferred in any manner other than by will or the laws of descent and distribution or, subject to the consent of the Administrator, pursuant to a DRO, unless and
until the Option has been exercised and the Shares underlying the Option have been issued, and all restrictions applicable to such Shares have lapsed. Neither the Option nor any interest or right therein shall be liable for the debts, contracts or
engagements of Participant or his or her successors in interest or shall be subject to disposition by transfer, alienation, anticipation, pledge, hypothecation, encumbrance, assignment or any other means whether such disposition be voluntary or
involuntary or by operation of law by judgment, levy, attachment, garnishment or any other legal or equitable proceedings (including bankruptcy) unless and until the Option has been exercised, and any attempted disposition thereof prior to exercise
shall be null and void and of no effect, except to the extent that such disposition is permitted by the preceding sentence. 

  
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 (b) During the lifetime of Participant, only Participant may exercise the Option (or any
portion thereof), unless it has been disposed of pursuant to a DRO; after the death of Participant, any exercisable portion of the Option may, prior to the time when such portion becomes unexercisable under the Plan or this Agreement, be exercised
by Participant’s personal representative or by any person empowered to do so under the deceased Participant’s will or under the then-applicable laws of descent and distribution. 

(c) Notwithstanding any other provision in this Agreement, Participant may, in the manner determined by the Administrator, designate a
beneficiary to exercise the rights of Participant and to receive any distribution with respect to the Option upon Participant’s death. A beneficiary, legal guardian, legal representative, or other person claiming any rights pursuant to the Plan
is subject to all terms and conditions of the Plan and this Agreement, except to the extent the Plan and this Agreement otherwise provide, and to any additional restrictions deemed necessary or appropriate by the Administrator. If Participant is
married or a domestic partner in a domestic partnership qualified under Applicable Law and resides in a community property state, a designation of a person other than Participant’s spouse or domestic partner, as applicable, as his or her
beneficiary with respect to more than 50% of Participant’s interest in the Option shall not be effective without the prior written consent of Participant’s spouse or domestic partner. If no beneficiary has been designated or survives
Participant, payment shall be made to the person entitled thereto pursuant to Participant’s will or the laws of descent and distribution. Subject to the foregoing, a beneficiary designation may be changed or revoked by Participant at any time
provided the change or revocation is filed with the Administrator prior to Participant’s death. 
 5.4 Tax Consultation.
Participant understands that Participant may suffer adverse tax consequences as a result of the grant, vesting or exercise of the Option, or with the purchase or disposition of the Shares subject to the Option. Participant represents that
Participant has consulted with any tax consultants Participant deems advisable in connection with the purchase or disposition of such Shares and that Participant is not relying on the Company for any tax advice. 

5.5 Binding Agreement. Subject to the limitation on the transferability of the Option contained herein, this Agreement will be binding
upon and inure to the benefit of the heirs, legatees, legal representatives, successors and assigns of the parties hereto. 
 5.6
Adjustments Upon Specified Events. The Administrator may accelerate the vesting of the Option in such circumstances as it, in its sole discretion, may determine. In addition, upon the occurrence of certain events relating to the Shares
contemplated by Article IX of the Plan (including, without limitation, an extraordinary cash dividend on such Shares), the Administrator shall make such adjustments the Administrator deems appropriate in the number of Shares subject to the Option,
the exercise price of the Option and the kind of securities that may be issued upon exercise of the Option. Participant acknowledges that the Option is subject to adjustment, modification and termination in certain events as provided in this
Agreement and Article IX of the Plan. 
 5.7 Notices. Any notice to be given under the terms of this Agreement to the Company shall be
addressed to the Company in care of the Secretary of the Company at the Company’s principal office, and any notice to be given to Participant shall be addressed to Participant at Participant’s last address reflected on the Company’s
records. By a notice given pursuant to this Section 5.7, either party may hereafter designate a different address for notices to be given to that party. Any notice which is required to be given to Participant shall, if Participant is then
deceased, be given to the person entitled to exercise his or her Option pursuant to Section 4.1 hereof by written notice under this Section 5.7. Any notice shall be deemed duly given when sent via email or when sent by certified mail
(return receipt requested) and deposited (with postage prepaid) in a post office or branch post office regularly maintained by the United States Postal Service (or similar no-U.S. entity). 

  
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 5.8 Titles. Titles are provided herein for convenience only and are not to serve as a
basis for interpretation or construction of this Agreement. 
 5.9 Governing Law. The laws of the State of Delaware shall govern the
interpretation, validity, administration, enforcement and performance of the terms of this Agreement regardless of the law that might be applied under principles of conflicts of laws. 

5.10 Conformity to Securities Laws. Participant acknowledges that the Plan and this Agreement are intended to conform to the extent
necessary with all provisions of the Securities Act and the Exchange Act and any and all Applicable Law and regulations and rules promulgated by the Securities and Exchange Commission thereunder, and state securities laws and regulations.
Notwithstanding anything herein to the contrary, the Plan shall be administered, and the Option is granted and may be exercised, only in such a manner as to conform to such Applicable Law. To the extent permitted by applicable law, the Plan and this
Agreement shall be deemed amended to the extent necessary to conform to such Applicable Law. 
 5.11 Amendment, Suspension and
Termination. To the extent permitted by the Plan, this Agreement may be wholly or partially amended or otherwise modified, suspended or terminated at any time or from time to time by the Administrator or the Board; provided, however,
that, except as may otherwise be provided by the Plan, no amendment, modification, suspension or termination of this Agreement shall adversely affect the Option in any material way without the prior written consent of Participant.

5.12 Successors and Assigns. The Company may assign any of its rights under this Agreement to single or multiple assignees, and this
Agreement shall inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer herein set forth in Section 5.3 hereof, this Agreement shall be binding upon Participant and his or her heirs, executors,
administrators, successors and assigns. 
 5.13 Notification of Disposition. If this Option is designated as an Incentive Stock
Option, Participant shall give prompt notice to the Company of any disposition or other transfer of any Shares acquired under this Agreement if such disposition or transfer is made (a) within two years from the Grant Date with respect to such
Shares or (b) within one year after the transfer of such Shares to Participant. Such notice shall specify the date of such disposition or other transfer and the amount realized, in cash, other property, assumption of indebtedness or other
consideration, by Participant in such disposition or other transfer. 
 5.14 Limitations Applicable to Section 16
Persons. Notwithstanding any other provision of the Plan or this Agreement, if Participant is subject to Section 16 of the Exchange Act, the Plan, the Option and this Agreement shall be subject to any additional limitations set forth in any
applicable exemptive rule under Section 16 of the Exchange Act (including any amendment to Rule 16b-3 of the Exchange Act) that are requirements for the application of such exemptive rule. To the extent
permitted by applicable law, this Agreement shall be deemed amended to the extent necessary to conform to such applicable exemptive rule. 

  
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 5.15 Not a Contract of Service Relationship. Nothing in this Agreement or in the Plan
shall confer upon Participant any right to continue to serve as an Employee or other service provider of the Company or any of its Subsidiaries or shall interfere with or restrict in any way the rights of the Company and its Subsidiaries, which
rights are hereby expressly reserved, to discharge or terminate the services of Participant at any time for any reason whatsoever, with or without cause, except to the extent expressly provided otherwise by Applicable Law or in a written agreement
between the Company or a Subsidiary and Participant. 
 5.16 Entire Agreement. The Plan, the Grant Notice and this Agreement
constitute the entire agreement of the parties and supersede in their entirety all prior undertakings and agreements of the Company and Participant with respect to the subject matter hereof, provided that the Option shall be subject to any
accelerated vesting provisions in any written agreement between Participant and the Company (or any Subsidiary who is the employer of Participant) or a Company plan pursuant to which Participant participates, in each case, in accordance with the
terms therein. 
 5.17 Section 409A. This Option is not intended to constitute “nonqualified deferred
compensation” within the meaning of Section 409A of the Code (together with any Department of Treasury regulations and other interpretive guidance issued thereunder, including without limitation any such regulations or other guidance that
may be issued after the date hereof, “Section 409A”). However, notwithstanding any other provision of the Plan, the Grant Notice or this Agreement, if at any time the Administrator determines
that the Option (or any portion thereof) may be subject to Section 409A, the Administrator shall have the right in its sole discretion (without any obligation to do so or to indemnify Participant or any other person for failure to do so) to
adopt such amendments to the Plan, the Grant Notice or this Agreement, or adopt other policies and procedures (including amendments, policies and procedures with retroactive effect), or take any other actions, as the Administrator determines are
necessary or appropriate either for the Option to be exempt from the application of Section 409A or to comply with the requirements of Section 409A.

5.18 Limitation on Participant’s Rights. Participation in the Plan confers no rights or interests other than as herein provided.
This Agreement creates only a contractual obligation on the part of the Company as to amounts payable and shall not be construed as creating a trust. Neither the Plan nor any underlying program, in and of itself, has any assets. Participant shall
have only the rights of a general unsecured creditor of the Company with respect to amounts credited and benefits payable, if any, with respect to the Option, and rights no greater than the right to receive the Shares as a general unsecured creditor
with respect to options, as and when exercised pursuant to the terms hereof. 

*    *    *    *    * 

  
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