Form of Lock-Up Agreement, dated June 29, 2023

Exhibit 10.3

EXECUTION VERSION

Lock-Up Agreement

June 29, 2023

Ladies and Gentlemen:

The undersigned (the “Stockholder”) understands that: (i) IMMUNOME INC., a Delaware corporation (“Parent”), has entered into an Agreement and Plan of Merger and Reorganization, dated as of June 29, 2023 (the “Merger Agreement”), with MORPHIMMUNE INC., a Delaware corporation (the “Company”), and Ibiza Merger Sub, Inc., a Delaware corporation and wholly-owned subsidiary of Parent (“Merger Sub”), pursuant to which at the effective time (the “Effective Time”), Merger Sub will be merged with and into the Company (the “Merger”) and the separate corporate existence of Merger Sub will cease and the Company will continue as the surviving corporation; and (ii) in connection with the Merger, the stockholders of the Company will receive shares of common stock, par value $0.0001 per share, of Parent (“Parent Common Stock”). Capitalized terms used but not otherwise defined herein shall have the respective meanings ascribed to such terms in the Merger Agreement.

As a material inducement to the willingness of each of the parties to enter into the Merger Agreement and to consummate the Contemplated Transactions, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Stockholder hereby agrees that the Stockholder will not, subject to the exceptions set forth in this letter agreement, during the period commencing upon the date hereof and ending on the date that is 180 days after the Effective Time (the “Restricted Period”), (a) 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, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Parent Common Stock or any securities convertible into or exercisable or exchangeable for Parent Common Stock, including without limitation, Parent Common Stock or such other securities which may be deemed to be beneficially owned by the Stockholder in accordance with the rules and regulations of the U.S. Securities and Exchange Commission and securities of Parent which may be issued upon exercise of a stock option or warrant or settlement of a restricted stock unit or other equity award (collectively, “Shares”), (b) 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 Shares, regardless of whether any such transaction described in clause (a) or (b) above is to be settled by delivery of Parent Common Stock or such other securities, in cash or otherwise, (c) make any demand for or exercise any right with respect to the registration of any shares of Parent Common Stock or any security convertible into or exercisable or exchangeable for Parent Common Stock, or (d) otherwise publicly announce any intention to engage in or cause any action or activity described in clauses (a) or (c) above or transaction or arrangement described in clause (b) above, in each case other than:

(i) transfers of Shares as bona fide charitable contributions, gifts or donations;

(ii) transfers or dispositions of Shares to any trust for the direct or indirect benefit of the Stockholder or the immediate family of the Stockholder;

(iii) transfers or dispositions of Shares by will, other testamentary document or intestate succession to the legal representative, heir, beneficiary or a member of the immediate family of the Stockholder;

(iv) transfers of Shares to stockholders, direct or indirect affiliates (within the meaning set forth in Rule 405 under the Securities Act), current or former partners (general or limited), members or managers of the Stockholder, as applicable, or to the estates of any such stockholders, affiliates, partners, members or managers, or to another corporation, partnership, limited liability company or other business entity that controls, is controlled by or is under common control with the Stockholder;

(v) transfers that occur by operation of law pursuant to a qualified domestic relations order or in connection with a divorce settlement;

(vi) transfers or dispositions not involving a change in beneficial ownership;

(vii) if the Stockholder is a trust, transfers or dispositions to any beneficiary of the Stockholder or the estate of any such beneficiary;

(viii) transfers pursuant to a bona fide third party tender offer, merger, consolidation or other similar transaction made to all holders of the Parent’s capital stock involving a change of control of the Parent, provided that in the event that such tender offer, merger, consolidation or other such transaction is not completed, the Shares shall remain subject to the restrictions contained in this letter agreement;

(ix) any sales in open market transactions (including, without limitation, the establishment of a 10b5-1 Plan (as defined below) and any sales pursuant to such 10b5-1 Plan) during the Restricted Period to generate such amount of net proceeds to the Stockholder from such sales (after deducting commissions) in an aggregate amount up to the total amount of taxes or estimated taxes (as applicable) that become due as a result of the vesting and/or settlement of restricted stock units held by the Stockholder that are scheduled to vest and/or settle immediately prior to or during the Restricted Period;

(x) in the case of an entity, by virtue of laws of the state of the entity’s organization and the entity’s organizational documents, upon dissolution of the entity; and

(xi) to the extent required by any legal or regulatory order;

provided, that in each case of clauses (i)-(vii), (a) no filing by any party (including any donor, donee, transferor or transferee, distributor or distributee) under the Exchange Act or other public announcement shall be required or shall be made voluntarily in connection with such transfer or distribution (other than filings made in respect of involuntary transfers or dispositions or a filing on a Form 5 made after the expiration of the Restricted Period), (b) any such transfer or distribution shall not involve a disposition for value, and (c) the transferee or donee agrees in writing to be bound by the terms and conditions of this letter agreement and either the Stockholder or the transferee or donee provides Parent with a copy of such agreement promptly upon consummation of any such transfer; provided further, that in the case of clause (ix), filings under Section 16(a) of the Exchange Act shall only be permissible if such filing clearly indicates in the footnotes thereto that the filing relates to securities being sold to generate net proceeds up to the total amount of taxes or estimated taxes (as applicable) that become due as a result of the vesting and/or settlement of Parent equity awards. For purposes of this letter agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin.

Notwithstanding the restrictions imposed by this letter agreement, the Stockholder may (a) exercise an option or warrant to purchase Shares or settle a restricted stock unit or other equity award (including a net or cashless exercise of such option or warrant provided the Shares are transferred to Parent and not sold on the open market) and provided further, that the underlying Shares shall continue to be subject to the restrictions on transfer set forth in this letter agreement, (b) transfer Shares to Parent or in open market transactions, in each case, to cover tax withholding obligations of the Stockholder in connection with the vesting, settlement or exercise of such options, warrants, restricted stock units or other equity awards, as applicable, provided that any such transfer of Shares in open market transactions shall only be permitted during the Stockholder’s post-termination exercise period in the event the Stockholder’s continuous service with Parent is terminated and that no filing under the Exchange Act or other public announcement shall be required or shall be made voluntarily in connection with such open market transactions, (c) establish a trading plan pursuant to Rule 10b5-1 under the Exchange Act (“10b5-1 Plan”) for the transfer of Shares, provided that such plan does not provide for any transfers of Shares during the Restricted Period (except as provided in clause (ix) above) and, provided further, that, no filing under the Exchange Act or other public announcement shall be required or shall be made voluntarily in connection with the establishment of such a plan unless such filing, disclosure or announcement is required to comply Section 16(a) of the Exchange Act or Item 408 of Regulation S-K, (d) transfer Shares to Parent pursuant to arrangements under which Parent has the option to repurchase such Shares, (e) transfer or dispose of Shares or other securities acquired pursuant to a Subscription Agreement or issued in exchange for, on conversion of or exercise of, any securities issued pursuant to the Subscription Agreement, or (f) transfer or dispose of Shares acquired on the open market following the Effective Time.

Any attempted transfer in violation of this letter 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 letter agreement, and will not be recorded on the stock transfer books of Parent. In order to ensure compliance with the restrictions referred to herein, the Stockholder agrees that Parent may issue appropriate “stop transfer” certificates or instructions. Parent may cause the legend set forth below, or a legend substantially equivalent thereto, to be placed upon any certificate(s) or other documents or instruments evidencing ownership of the Shares:

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.

The Stockholder hereby represents and warrants that the Stockholder has full power and authority to enter into this letter agreement. All authority conferred or agreed to be conferred and any obligations of the Stockholder under this letter agreement will be binding upon the successors, assigns, heirs or personal representatives of the Stockholder.

In the event that during the Restricted Period any holder of Parent’s securities that is subject to a substantially similar agreement entered into by such holder, other than the Stockholder, is permitted by Parent to sell or otherwise transfer or dispose of shares of Parent 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 Parent Common Stock held by the Stockholder 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 Parent 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 Parent Common Stock in an aggregate amount in excess of 1% of the number of shares of Parent Common Stock originally subject to a substantially similar agreement.

Upon the release of any Shares from this letter agreement, Parent will cooperate with the Stockholder to facilitate the timely preparation and delivery of certificates or the establishment of book entry positions at the Parent’s transfer agent representing the Shares without the restrictive legend above and the withdrawal of any stop transfer instructions at the Parent’s transfer agent.

The Stockholder understands that each of Parent and the Company is relying upon this letter agreement in proceeding toward consummation of the Merger. The Stockholder further understands that this letter agreement is irrevocable and is binding upon the Stockholder’s heirs, legal representatives, successors and assigns.

[With respect to the Parent Post-Closing Financing (as defined in the Merger Agreement), the Stockholder waives any registration rights relating to registration under the Securities Act of the offer and sale of any Shares owned either of record or beneficially by the Stockholder, including any and all rights and notice rights set forth in any registration rights agreement or investors’ rights agreement to which the Stockholder and Parent may be a party.]

This letter agreement and any claim, controversy or dispute arising under or related to this letter 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.

The Stockholder understands that if the Merger Agreement is terminated in accordance with its terms, the Stockholder will be released from all obligations under this letter agreement.

This letter agreement may be executed by electronic transmission (including .PDF format or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., DocuSign), which is deemed an original.

[Signature Page Follows]

[Signature Page to Lock-up Agreement]