Exhibit 10.3


 


LOCK-UP AGREEMENT


 


March [●], 2021


 


Millendo Therapeutics, Inc.


110 Miller Avenue, Suite 100


Ann Arbor, Michigan


 


Ladies and Gentlemen:


 


The undersigned signatory of this lock-up agreement
(this “Lock-Up Agreement”) understands that Millendo Therapeutics, Inc., a Delaware corporation (“Public Company”),
has entered into an Agreement and Plan of Merger, dated as of [●], 2021 (as the same may be amended from time to time, the “Merger
Agreement”) with Mars Merger Corp., a Delaware corporation and a wholly owned subsidiary of Public Company, and Tempest Therapeutics,
Inc., a Delaware corporation. Capitalized terms used but not otherwise defined herein shall have the respective meanings ascribed to such
terms in the Merger Agreement.


 


As a condition and inducement to Public Company
to enter into the Merger Agreement and to consummate the transactions contemplated thereby, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby irrevocably agrees that, subject to the exceptions
set forth herein, without the prior written consent of Public Company, the undersigned will not, during the period commencing upon the
Closing and ending on the date that is 180 days after the Closing Date (the “Restricted Period”):


 


(1)              
offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option,
right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Public Company Common Stock or
any securities convertible into or exercisable or exchangeable for shares of Public Company Common Stock (including without limitation,
shares of Public Company Common Stock or such other securities which may be deemed to be beneficially owned by the undersigned in accordance
with the rules and regulations of the SEC and securities of Public Company which may be issued upon exercise of an option to purchase
shares of Public Company Common Stock or a warrant to purchase shares of Public Company Common Stock) that are currently or hereafter
owned by the undersigned, except as set forth below (collectively, the “Undersigned’s Shares”), or publicly disclose
the intention to make any such offer, sale, pledge, grant, transfer or disposition;


 


(2)              
enter into any swap, short sale, hedge or other agreement that transfers, in whole or in part, any of the economic consequences of ownership
of the Undersigned’s Shares regardless of whether any such transaction described in clause (1) above or this clause (2) is to be
settled by delivery of shares of Public Company Common Stock or other securities, in cash or otherwise; or


 


(3)             make any demand for, or exercise any right with respect to, the registration of any shares of Public Company Common Stock or any security
convertible into or exercisable or exchangeable for shares of Public Company Common Stock (other than such rights set forth in the Merger
Agreement).


 






    


     


    

 





The restrictions and obligations contemplated
by this Lock-Up Agreement shall not apply to:


 


(a)              
transfers of the Undersigned’s Shares:


 


(1)              
if the undersigned is a natural person, (A) to any person related to the undersigned by blood or adoption who is an immediate family
member of the undersigned, or by marriage or domestic partnership (a “Family Member”), or to a trust formed for the
benefit of the undersigned or any of the undersigned’s Family Members, (B) to the undersigned’s estate, following the death
of the undersigned, by will, intestacy or other operation of Law, (C) as a bona fide gift or a charitable contribution, (D) by operation
of Law pursuant to a qualified domestic order or in connection with a divorce settlement or (E) to any partnership, corporation or limited
liability company which is controlled by the undersigned and/or by any such Family Member(s);


 


(2)              
if the undersigned is a corporation, partnership or other entity, (A) to another corporation, partnership, or other entity that
is an affiliate (as defined under Rule 12b-2 of the Exchange Act) of the undersigned, including investment funds or other entities under
common control or management with the undersigned, (B) as a distribution or dividend to equity holders, current or former general or limited
partners, members or managers (or to the estates of any of the foregoing), as applicable, of the undersigned (including upon the liquidation
and dissolution of the undersigned pursuant to a plan of liquidation approved by the undersigned’s equity holders), (C) as a bona
fide gift or a charitable contribution or (D) transfers or dispositions not involving a change in beneficial ownership; or


 


(3)              
if the undersigned is a trust, to any grantors or beneficiaries of the trust;


 


provided that, in the
case of any transfer or distribution pursuant to this clause (a), such transfer is not for value and each donee, heir, beneficiary or
other transferee or distributee shall sign and deliver to Public Company a lock-up agreement in the form of this Lock-Up Agreement with
respect to the shares of Public Company Common Stock or such other securities that have been so transferred or distributed;


 


(b)              
the exercise of an option to purchase shares of Public Company Common Stock (including a net or cashless exercise of an option to purchase
shares of Public Company Common Stock ), and any related transfer of shares of Public Company Common Stock to Public Company for the purpose
of paying the exercise price of such options or for paying taxes (including estimated taxes) due as a result of the exercise of such options;
provided that, for the avoidance of doubt, the underlying shares of Public Company Common Stock shall continue to be subject to
the restrictions on transfer set forth in this Lock-Up Agreement;


 


(c)              
transfers to Public Company in connection with the net settlement of any other equity award that represents the right to receive in the
future shares of Public Company Common Stock, settled in shares of Public Company Common Stock, to pay any tax withholding obligations;
provided that, for the avoidance of doubt, the underlying shares of Public Company Common Stock shall continue to be subject to
the restrictions on transfer set forth in this Lock-Up Agreement;


 


(d)              
the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of Public Company
Common Stock; provided that such plan does not provide for any transfers of shares of Public Company Common Stock during the
Restricted Period;


 






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(e)              
transfers by the undersigned of shares of Public Company Common Stock purchased by the undersigned on the open market or in a public offering
by Public Company, in each case following the Closing Date;


 


(f)               
pursuant to a bona-fide third party tender offer, merger, consolidation or other similar transaction made to all holders of Public Company’s
capital stock involving a change of control of Public Company, provided that in the event that such tender offer, merger, consolidation
or other such transaction is not completed, the Undersigned’s Shares shall remain subject to the restrictions contained in this
Lock-Up Agreement; or


 


(g)              
pursuant to an order of a court or regulatory agency;


 


and provided, further,
that, with respect to each of (a), (b), (c), and (d) above, no filing by any party (including any donor, donee, transferor, transferee,
distributor or distributee) under Section 16 of the Exchange Act or other public announcement shall be required or shall be made voluntarily
in connection with such transfer or disposition during the Restricted Period (other than (x) any exit filings or public announcements
that may be required under applicable federal and state securities Laws or (y) in respect of a required filing under the Exchange Act
in connection with the exercise of an option to purchase shares of Public Company Common Stock or in connection with the net settlement
of any other equity award that represents the right to receive in the future shares of Public Company Common Stock, settled in shares
of Public Company Common Stock, that would otherwise expire during the Restricted Period, provided that reasonable notice shall
be provided to Public Company prior to any such filing). For the avoidance of doubt, the Undersigned’s Shares shall not include
any securities acquired by the undersigned pursuant to any Funding Agreement.


 


Any attempted transfer in violation of this Lock-Up
Agreement will be of no effect and null and void, regardless of whether the purported transferee has any actual or constructive knowledge
of the transfer restrictions set forth in this Lock-Up Agreement, and will not be recorded on the share register of Public Company. In
furtherance of the foregoing, the undersigned agrees that Public Company and any duly appointed transfer agent for the registration or
transfer of the securities described herein are hereby authorized to decline to make any transfer of securities if such transfer would
constitute a violation or breach of this Lock-Up Agreement. Public Company may cause the legend set forth below, or a legend substantially
equivalent thereto, to be placed upon any certificate(s) or other documents, ledgers or instruments evidencing the undersigned’s
ownership of shares of Public Company Common Stock:


 


THE SHARES REPRESENTED BY THIS CERTIFICATE
ARE SUBJECT TO AND MAY ONLY BE TRANSFERRED IN COMPLIANCE WITH A LOCK-UP AGREEMENT, A COPY OF WHICH IS ON FILE AT THE PRINCIPAL OFFICE
OF THE COMPANY.


 






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The undersigned hereby represents and warrants
that the undersigned has full power and authority to enter into this Lock-Up Agreement. All authority herein conferred or agreed to be
conferred and any obligations of the undersigned shall be binding upon the successors, assigns, heirs or personal representatives of the
undersigned.


 


The undersigned understands that if the Merger
Agreement is terminated for any reason, the undersigned shall be released from all obligations under this Lock-Up Agreement. The undersigned
understands that Public Company is proceeding with the transactions contemplated by the Merger Agreement in reliance upon this Lock-Up
Agreement.


 


Any and all remedies herein expressly conferred
upon Public Company will be deemed cumulative with and not exclusive of any other remedy conferred hereby, or by Law or equity, and the
exercise by Public Company of any one remedy will not preclude the exercise of any other remedy. The undersigned agrees that irreparable
damage would occur to Public Company in the event that any provision of this Lock-Up Agreement was not performed in accordance with its
specific terms or were otherwise breached. It is accordingly agreed that Public Company shall be entitled to an injunction or injunctions
to prevent breaches of this Lock-Up Agreement and to enforce specifically the terms and provisions hereof in any court of the United States
or any state having jurisdiction, this being in addition to any other remedy to which Public Company is entitled at Law or in equity,
and the undersigned waives any bond, surety or other security that might be required of Public Company with respect thereto.


 


In the event that any holder of Public Company’s
securities that are subject to a substantially similar agreement entered into by such holder, other than the undersigned, is permitted
by Public Company to sell or otherwise transfer or dispose of shares of Public Company Common Stock for value other than as permitted
by this or a substantially similar agreement entered into by such holder, the same percentage of shares of Public Company Common Stock
held by the undersigned shall be immediately and fully released on the same terms from any remaining restrictions set forth herein (the
 “Pro-Rata Release”); provided, however, that such Pro-Rata Release shall not be applied unless and until
permission has been granted by Public Company to an equity holder or equity holders to sell or otherwise transfer or dispose of all or
a portion of such equity holders’ shares of Public Company Common Stock in an aggregate amount in excess of 1% of the number of
shares of Public Company Common Stock originally subject to a substantially similar agreement.


 


Upon the release of any of the Undersigned’s
Shares from this Lock-Up Agreement, Public Company will cooperate with the undersigned to facilitate the timely preparation and delivery
of certificates representing the Undersigned Shares without the restrictive legend above or the withdrawal of any stop transfer instructions
by virtue of this Lock-Up Agreement.


 


This Lock-Up Agreement and any claim, controversy
or dispute arising under or related to this Lock-Up Agreement shall be governed by and construed in accordance with the Laws of the state
of Delaware, without regard to the conflict of Laws principles thereof.


 


This Lock-Up Agreement may be executed in
several counterparts, each of which shall be deemed an original and all of which shall constitute one and the same instrument. The
exchange of a fully executed Lock-Up Agreement (in counterparts or otherwise) by Public Company and the undersigned by facsimile or
electronic transmission in .pdf format shall be sufficient to bind such parties to the terms and conditions of this Lock-Up
Agreement.


 


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	Very truly yours,	 
	 	 
	[STOCKHOLDER]	 
	 	 
	Signature:	 	 
	 	 
	[STOCKHOLDER]	 
	 	 
	Signature:	 	 
	 	 
	Name:	 	 
	 	 
	Title:	 	 



 


[Signature Page to Lock-up Agreement]


 






    


     


    

 





	Accepted and Agreed	 
	by Millendo Therapeutics, Inc.:	 
	 	 
	By:	 	 
	 	Name:	 
	 	Title:	 



 


[Signature Page to Lock-up Agreement]