FORM OF PARENT STOCKHOLDER SUPPORT AGREEMENT

Exhibit 10.1

FORM OF PARENT STOCKHOLDER SUPPORT AGREEMENT

This Support Agreement (this “Agreement”) is made and entered into as of [•], 2024, by and among Kalaris Therapeutics, Inc., a Delaware corporation (the “Company”), AlloVir, Inc., a Delaware corporation (“Parent”), and the undersigned holder (the “Stockholder”) of Shares (as defined below) of Parent. Capitalized terms used herein but not otherwise defined shall have the respective meanings ascribed to such terms in the Merger Agreement (as defined below).

RECITALS

WHEREAS, concurrently with the execution and delivery hereof, Parent, the Company and Aurora Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (the “Merger Sub”), have entered into an Agreement and Plan of Merger, dated of even date herewith (as such agreement may be amended or supplemented from time to time pursuant to the terms thereof, the “Merger Agreement”), pursuant to which Merger Sub will merge with and into the Company (the “Merger”), with the Company surviving the Merger as the surviving corporation and a wholly owned subsidiary of Parent upon the terms and subject to the conditions set forth in the Merger Agreement.

WHEREAS, as of the date hereof, the Stockholder is the beneficial owner (as defined in Rule 13d-3 under the Exchange Act) of the Shares, and holds Parent Options, Parent Restricted Stock Awards or Parent Restricted Stock Unit Awards to acquire the number of Shares, as indicated opposite such Stockholder’s name on Schedule A.

WHEREAS, as an inducement and a condition to the willingness of the Company to enter into the Merger Agreement, each Stockholder has agreed to enter into and perform this Agreement.

NOW, THEREFORE, in consideration of, and as a condition to, the Company’s entering into the Merger Agreement, each Stockholder, Parent and the Company agree as follows:

1. Certain Definitions. Capitalized terms used but not otherwise defined herein shall have the meanings ascribed thereto in the Merger Agreement. For all purposes of this Agreement, the following terms shall have the following respective meanings:

(a) “Constructive Sale” means, with respect to any security, a short sale with respect to such security, entering into or acquiring a derivative contract with respect to such security, entering into or acquiring a futures or forward contract to deliver such security or entering into any other hedging or other derivative transaction that has the effect of either directly or indirectly materially changing the economic benefits or risks of ownership of such security.

(b) “Shares” means (i) all shares of Parent Common Stock owned, beneficially or of record, by the Stockholder as of the date hereof, (ii) all additional shares of Parent Common Stock acquired by the Stockholder, beneficially or of record, during the period commencing with the execution and delivery of this Agreement and expiring on the Expiration Date (as defined below) and (iii) any shares of capital stock or other equity securities of Parent that such Stockholder acquires or with respect to which such Stockholder otherwise acquires sole or shared voting power (including any proxy) after the execution and delivery of this Agreement and expiring on the Expiration Date, whether by exercise of any Parent Options, settlement of Parent Restricted Stock Awards, Parent Restricted Stock Unit Awards or any securities convertible into or exercisable or exchangeable or redeemable for shares of Parent Common Stock in which such Stockholder acquires record or beneficial ownership on or after the date hereof, whether by purchase, upon exercise or conversion of any securities or otherwise, including, without limitation, by gift, succession, in the event of a stock split or as a dividend or distribution of any shares of Parent Common Stock.

(c) “Transfer” or “Transferred” means, with respect to any security, the direct or indirect assignment, sale, transfer, tender, exchange, pledge or hypothecation, or the grant, creation or suffrage of a lien, security interest or encumbrance in or upon, or the gift, grant or placement in trust, or the Constructive Sale or other disposition of such security (including transfers by testamentary or intestate succession, by domestic relations order or other court order, or otherwise by operation of law) or any right, title or interest therein (including any right or power to vote to which the holder thereof may be entitled, whether such right or power is granted by proxy or otherwise), or the record or beneficial ownership thereof, the offer to make such a sale, transfer, Constructive Sale or other disposition, and each agreement, arrangement or understanding, whether or not in writing, to effect any of the foregoing.

Page 1

2. Transfer and Voting Restrictions. The Stockholder covenants to the Company as follows:

(a) Except as otherwise permitted by Section 2(c), during the period commencing with the execution and delivery of this Agreement and expiring on the Expiration Date, the Stockholder shall not Transfer any of the Stockholder’s Shares, or publicly announce its intention to Transfer any of its Shares.

(b) Except as otherwise permitted by this Agreement or otherwise permitted or required or by order of a court of competent jurisdiction or a Governmental Entity, the Stockholder will not commit any act that would restrict the Stockholder’s legal power, authority and right to vote all of the Shares held by the Stockholder or otherwise prevent or disable the Stockholder from performing any of his, her or its obligations under this Agreement. Without limiting the generality of the foregoing, except for this Agreement and as otherwise permitted by this Agreement, the Stockholder shall not enter into any voting agreement with any person or entity with respect to any of the Stockholder’s Shares, grant any person or entity any proxy (revocable or irrevocable) or power of attorney with respect to any of the Shares, deposit any Shares in a voting trust or otherwise enter into any agreement or arrangement with any person or entity limiting or affecting the Stockholder’s legal power, authority or right to vote the Stockholder’s Shares in favor of the Parent Stockholder Proposals and against any other Acquisition Proposals.

(c) Except as otherwise permitted by this Agreement or otherwise permitted or required by order of a court of competent jurisdiction or a Governmental Entity, the Stockholder will not enter into any Contract, option, commitment or other arrangement or understanding with respect to the direct or indirect Transfer of any right, title or interest (including any right or power to vote to which the holder thereof may be entitled whether such right or power is granted by proxy or otherwise) to any Shares or take any action that would reasonably be expected to make any representation or warranty of such Stockholder contained herein untrue or incorrect or have the effect of restricting the Stockholder’s legal power, authority and right to vote all of the Shares or would otherwise prevent or disable such Stockholder from performing any of such Stockholder’s obligations under this Agreement.

(d) Notwithstanding anything else herein to the contrary, the Stockholder may, at any time, Transfer Shares (i) by will or other testamentary document or by intestacy, (ii) to any investment fund or other entity controlled or managed by the Stockholder or the investment adviser or general partner of the Stockholder, or an entity under common control or management with the Stockholders (in each case, directly or indirectly), (iii) to any member of the Stockholder’s immediate family (or, if the Stockholder is a corporation, partnership or other entity, to an immediate family member of a beneficial owner of the Shares held by the Stockholder), (iv) to any trust or other entity for the direct or indirect benefit of the Stockholder or the immediate family of the Stockholder (or, if the Stockholder is a corporation, partnership or other entity, for the direct or indirect benefit of an immediate family member of a beneficial owner of the Shares held by the Stockholder) or otherwise for estate tax or estate planning purposes, (v) in the case of a Stockholder who is not a natural person, by pro rata distributions from the Stockholder to its members, partners, or shareholders pursuant to the Stockholder’s organizational documents, (vi) with respect to such Stockholder’s Parent Options (and any Shares underlying such Parent Options) which expire on or prior to the Expiration Date, Transfers of Shares to Parent (or effecting a “net exercise” of a Parent Option) as payment for the (a) exercise price of such Stockholder’s Parent Options and (b) taxes applicable to the exercise of such Stockholder’s Parent Options, (vii) with respect to such Stockholder’s Parent Restricted Stock Unit Awards, (a) transfers for the net settlement of Stockholder’s Parent Restricted Stock Unit Awards settled in Shares (to pay any tax withholding obligations) or (b) transfers for receipt upon settlement of such Stockholder’s Parent Restricted Stock Unit Awards, and the sale of a sufficient number of such Shares acquired upon settlement of such securities as would generate sales proceeds sufficient to pay the aggregate taxes payable by such Stockholder as a result of the settlement, (viii) with respect to such Stockholder’s Parent Restricted Stock Awards, (a) transfers for the net settlement of Stockholder’s Parent Restricted Stock Awards settled in Shares (to pay any tax withholding obligations) or (b) transfers for receipt upon settlement of such Stockholder’s Parent Restricted Stock Awards, and the sale of a sufficient number of such Shares acquired upon settlement of such securities as would generate sales proceeds sufficient to pay the aggregate taxes payable by such Stockholder as a result of the settlement, (ix) transfers to another holder of capital stock of Parent that has signed a support agreement that is reasonably acceptable to the Company, (x) transfers, sales or other dispositions as the Company may otherwise agree in writing in its sole discretion; provided, that in the cases of clauses (i)-(x), (a) such Transferred Shares shall continue to be bound by this Agreement and (b) the applicable direct transferee (if any) of such Transferred Shares shall have executed and delivered to Parent and the Company a support agreement substantially identical to this Agreement upon consummation of the Transfer, or (xi) to the extent required by applicable Law.

Page 2

3. Agreement to Vote Shares. The Stockholder covenants to the Company as follows:

(a) Until the Expiration Date, at any meeting of the stockholders of Parent, however called, and at every adjournment or postponement thereof, and on every action or approval by written consent of the stockholders of Parent, the Stockholder shall (i) appear at such meeting as present (in person or by proxy) for purposes of calculating a quorum and (ii) vote, or exercise its right to consent with respect to, all Shares held by the Stockholder (1)(A) in favor of the Parent Stockholder Proposals, (B) in favor of any matter that could reasonably be expected to facilitate the Merger and the transactions contemplated by the Merger Agreement, and (C) against any Acquisition Proposals, or any agreement, transaction or other matter that is intended to, or would reasonably be expected to impede, interfere with, delay, postpone or materially and adversely affect the consummation of the Merger and the transactions contemplated in the Merger Agreement and (2) to approve any proposal to adjourn or postpone the meeting to a later date, if there are not sufficient votes for the issuance of the shares of Parent Common Stock by virtue of the Merger on the date on which such meeting is held. Stockholder shall not take or commit or agree to take any action inconsistent with the foregoing.

(b) If the Stockholder is the beneficial owner, but not the record holder, of Xxxxxx, the Stockholder agrees to take all actions necessary to cause the record holder and any nominees to be present (in person or by proxy) and vote all the Stockholder’s Shares in accordance with this Section 3.

(c) In the event of a stock split, stock dividend or distribution, or any change in the capital stock of Parent by reason of any split-up, reverse stock split, recapitalization, combination, reclassification, reincorporation, exchange of shares or the like, the term “Shares” shall be deemed to refer to and include such shares as well as all such stock dividends and distributions and any securities into which or for which any or all of such shares may be changed or exchanged or which are received in such transaction.

4. Action in Stockholder Capacity Only. The Stockholder is entering into this Agreement solely in the Stockholder’s capacity as a record holder and/or beneficial owner, as applicable, of its Shares and not in the Stockholder’s capacity as a director or officer of Parent. Nothing herein shall limit or affect the Stockholder’s ability to act as an officer or director of Parent.

5. Irrevocable Proxy. The Stockholder hereby revokes (or agrees to cause to be revoked) any proxies that the Stockholder has heretofore granted with respect to its Shares. In the event and to the extent that the Stockholder fails to vote the Shares in accordance with Section 3 at any applicable meeting of the stockholders of Parent or pursuant to any applicable written consent of the stockholders of Parent, the Stockholder shall be deemed to have irrevocably granted to, and appointed, Parent, and any individual designated in writing by it, and each of them individually, as his, her or its proxy and attorney-in-fact (with full power of substitution), for and in its name, place and stead, to vote his, her or its Shares in any action by written consent of Parent stockholders or at any meeting of Parent’s stockholders called with respect to any of the matters specified in, and in accordance and consistent with, Section 3 of this Agreement. Parent agrees not to exercise the proxy granted herein for any purpose other than the purposes described in this Agreement and the Stockholder affirms that the proxy set forth in this Section 5 is given in connection with, and granted in consideration of, and as an inducement to the Company, Parent and Merger Sub to enter into the Merger Agreement and that such proxy is given to secure the obligations of the Stockholder under Section 3. Except as otherwise provided for herein, the Stockholder hereby affirms that the irrevocable proxy is coupled with an interest and may under no circumstances be revoked and that such irrevocable proxy is executed and intended to be irrevocable. The irrevocable proxy and power of attorney granted herein shall survive the death or incapacity of such Stockholder and the obligations of such Stockholder shall be binding on such Stockholder’s heirs, personal representatives, successors, transferees and assigns. Notwithstanding any other provisions of this Agreement, the irrevocable proxy granted hereunder shall automatically terminate upon the termination of this Agreement.

Page 3

6. No Solicitation. Subject to Section 4, the Stockholder agrees not to, directly or indirectly, including through any of its officers, directors or agents, (i) solicit, initiate or knowingly encourage, induce or facilitate the communication, making, submission or announcement of any Acquisition Proposal or Acquisition Inquiry or offer relating to any Acquisition Transaction or take any action that could reasonably be expected to lead to an Acquisition Proposal, Acquisition Inquiry or Acquisition Transaction, (ii) furnish any nonpublic information regarding such party to any Person (other than to either Parent or the Company, as applicable) in connection with or in response to an Acquisition Proposal or Acquisition Inquiry, (iii) engage or participate in discussions or negotiations with any Person with respect to any Acquisition Proposal or Acquisition Inquiry, (iv) approve, endorse or recommend any Acquisition Proposal (subject to Section 7.2 and Section 7.3 of the Merger Agreement), (v) execute or enter into any letter of intent or any Contract contemplating or otherwise relating to any Acquisition Transaction, (vi) take any action that could reasonably be expected to lead to an Acquisition Proposal or Acquisition Inquiry or (vii) publicly propose to do any of the following. Without limiting the generality of the foregoing, each party acknowledges and agrees that, in the event any Representative of such party takes any action that, if taken by such party, would constitute a breach of this Section 6 by such party, the taking of such action by such Representative shall be deemed to constitute a breach of this Section 6 by such party for purposes of this Agreement. Notwithstanding the foregoing, the Stockholder will not be responsible for the breaches by its officers, directors or agents that have otherwise entered into a separate support agreement with the Parent and/or Company, unless the Stockholder knowingly and intentionally caused such breach.

7. No Exercise of Appraisal Rights; Waivers. The Stockholder hereby irrevocably and unconditionally (a) waives, and agrees to cause to be waived and to prevent the exercise of, any rights of appraisal, any dissenters’ rights and any similar rights (including any notice requirements related thereto) relating to the Merger that Stockholder may have by virtue of, or with respect to, any Shares (including all rights under Section 262 of the DGCL) and (b) agrees that the Stockholder will not bring, commence, institute, maintain, prosecute or voluntarily aid or participate in any action, claim, suit or cause of action, in law or in equity, in any court or before any Governmental Entity, which (i) challenges the validity of or seeks to enjoin the operation of any provision of this Agreement or (ii) alleges that the execution and delivery of this Agreement by the Stockholder, or the approval of the Merger Agreement by the Parent Board, breaches any fiduciary duty of the Parent Board or any member thereof; provided, that the Stockholder may defend against, contest or settle any such action, claim, suit or cause of action brought against the Stockholder that relates solely to the Stockholder’s capacity as a director, officer or securityholder of Parent.

8. Representations and Warranties of the Stockholder. The Stockholder hereby represents and warrants to the Company as follows:

(a) (i) The Stockholder is the beneficial or record owner of the shares of Parent Common Stock, Parent Options, Parent Restricted Stock Awards and/or Parent Restricted Stock Unit Awards indicated in Appendix A (each of which shall be deemed to be “held” by the Stockholder for purposes of Section 3 unless otherwise expressly stated with respect to any shares in Appendix A), free and clear of any and all Liens; and (ii) the Stockholder does not beneficially own any securities of Parent other than the shares of Parent Common Stock and rights to purchase shares Parent Common Stock set forth in Appendix A.

(b) With respect to any Stockholder that is an entity, the Stockholder is duly organized, validly existing and in good standing under the laws of the jurisdiction of its formation and is qualified to conduct its business in those jurisdictions necessary to perform this Agreement.

(c) Except as otherwise provided in this Agreement, the Stockholder has full power, legal capacity and authority to (i) make, enter into and carry out the terms of this Agreement and (ii) vote all of its Shares in the manner set forth in this Agreement without the consent or approval of, or any other action on the part of, any other person or entity (including any Governmental Entity). Without limiting the generality of the foregoing, the Stockholder has not entered into any voting agreement (other than this Agreement) with any person with respect to any of the Stockholder’s Shares, granted any person any proxy (revocable or irrevocable) or power of attorney with respect to any of the Stockholder’s Shares, deposited any of the Stockholder’s Shares in a voting trust or entered into any arrangement or agreement with any person limiting or affecting the Stockholder’s legal power, authority or right to vote the Stockholder’s Shares on any matter contemplated by this Agreement.

Page 4

(d) This Agreement has been duly and validly executed and delivered by the Stockholder and (assuming the due authorization, execution and delivery by the other parties hereto) constitutes a valid and binding agreement of the Stockholder enforceable against the Stockholder in accordance with its terms, subject to (a) Laws of general application relating to bankruptcy, insolvency and the relief of debtors and (b) rules of law governing specific performance, injunctive relief and other equitable remedies. The execution and delivery of this Agreement by the Stockholder and the performance by the Stockholder of the agreements and obligations hereunder will not result in any breach or violation of or be in conflict with or constitute a default under any term of any Contract or if applicable any provision of an organizational document (including a certificate of incorporation) to or by which the Stockholder is a party or bound, or any applicable law to which the Stockholder (or any of the Stockholder’s assets) is subject or bound, except for any such breach, violation, conflict or default which, individually or in the aggregate, would not reasonably be expected to materially impair or adversely affect the Stockholder’s ability to perform its obligations under this Agreement.

(e) The execution, delivery and performance of this Agreement by the Stockholder do not and will not require any consent, approval, authorization or permit of, action by, filing with or notification to, any Governmental Entity, except for any such consent, approval, authorization, permit, action, filing or notification the failure of which to make or obtain, individually or in the aggregate, has not and would not materially impair the Stockholder’s ability to perform its obligations under this Agreement.

(f) The Stockholder has had the opportunity to review the Merger Agreement and this Agreement with counsel of the Stockholder’s own choosing. The Stockholder has had an opportunity to review with its own tax advisors the tax consequences of the Merger and the transactions contemplated thereby. The Stockholder understands that it must rely solely on its advisors and not on any statements or representations made by Parent, the Company or any of their respective agents or representatives with respect to the tax consequences of the Merger and the transactions contemplated thereby. The Stockholder understands that such Stockholder (and not Parent, the Company or the Surviving Corporation) shall be responsible for such Stockholder’s tax liability that may arise as a result of the Merger or the transactions contemplated thereby. The Stockholder understands and acknowledges that the Company, Parent and Merger Sub are entering into the Merger Agreement in reliance upon the Stockholder’s execution, delivery and performance of this Agreement.

(g) With respect to the Stockholder, as of the date hereof, there is no action, suit, investigation or proceeding pending against, or, to the knowledge of the Stockholder, threatened against, the Stockholder or any of the Stockholder’s properties or assets (including the Shares) that would reasonably be expected to prevent or materially delay or impair the ability of the Stockholder to perform its obligations hereunder or to consummate the transactions contemplated hereby.

9. Termination. This Agreement shall terminate and shall cease to be of any further force or effect as of the earliest of (a) such date and time as the Merger Agreement shall have been terminated pursuant to the terms thereof, (b) the Effective Time or (c) the mutual written agreement of the parties to terminate this Agreement (clauses (a)-(c), the “Expiration Date”); provided, however, that (i) Section 10 shall survive the termination of this Agreement, and (ii) the termination of this Agreement shall not relieve any party hereto from any liability for any material and willful breach of this Agreement prior to the Effective Time.

10. Miscellaneous Provisions.

(a) Amendments. No amendment of this Agreement shall be effective against any party unless it shall be in writing and signed by each of the parties hereto.

(b) Entire Agreement. This Agreement constitutes the entire agreement between the parties to this Agreement and supersedes all other prior agreements, arrangements and understandings, both written and oral, among the parties with respect to the subject matter hereof.

(c) Governing Law. All matters arising out of or relating to this Agreement and the transactions contemplated hereby (including its interpretation, construction, performance and enforcement) shall be governed by and construed in accordance with the internal laws of the State of Delaware without giving effect to any choice or conflict of law provision or rule (whether of the State of Delaware or any other jurisdiction) that would cause the application of laws of any jurisdictions other than those of the State of Delaware.

Page 5

(d) Jurisdiction. Each of the parties to this Agreement (i) consents to submit itself to the exclusive personal jurisdiction of the Court of Chancery of the State of Delaware, New Castle County, or, if that court does not have jurisdiction, a federal court sitting in Wilmington, Delaware in any action or proceeding arising out of or relating to this Agreement or any of the transactions contemplated by this Agreement, (ii) agrees that all claims in respect of such action or proceeding shall be heard and determined in any such court, (iii) agrees that it shall not attempt to deny or defeat such personal jurisdiction by motion or other request for leave from any such court and (iv) agrees not to bring any action or proceeding arising out of or relating to this Agreement or any of the transactions contemplated by this Agreement in any other court. Each of the parties hereto waives any defense of inconvenient forum to the maintenance of any action or proceeding so brought and waives any bond, surety or other security that might be required of any other party with respect thereto. Any party may make service on another party by sending or delivering a copy of the process to the party to be served at the address and in the manner provided for the giving of notices in Section 10(j). Nothing in this Section 10(d), however, shall affect the right of any party to serve legal process in any other manner permitted by law.

(e) WAIVER OF JURY TRIAL. EACH OF THE PARTIES TO THIS AGREEMENT HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM (WHETHER BASED ON CONTRACT, TORT OR OTHERWISE) ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THE ACTIONS OF ANY PARTY TO THIS AGREEMENT IN THE NEGOTIATION, ADMINISTRATION, PERFORMANCE AND ENFORCEMENT OF THIS AGREEMENT.

(f) Assignment. Except as otherwise provided in Section 2(d) hereof, no party may assign any of its rights or delegate any of its performance obligations under this Agreement, in whole or in part, by operation of law or otherwise, without the prior written consent of the other parties hereto, and any such assignment without such prior written consent shall be null and void. Subject to the preceding sentence, this Agreement shall be binding upon, inure to the benefit of, and be enforceable by, the parties hereto and their respective successors and permitted assigns. Any purported assignment of rights or delegation of performance obligations in violation of this Section 10(f) is void.

(g) No Third Party Rights. This Agreement is not intended to, and shall not, confer upon any other person any rights or remedies hereunder other than the parties hereto to the extent expressly set forth herein.

(h) Severability. Any term or provision of this Agreement that is invalid or unenforceable in any situation in any jurisdiction shall not affect the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the offending term or provision in any other situation or in any other jurisdiction. If the final judgment of a court of competent jurisdiction declares that any term or provision hereof is invalid or unenforceable, the parties hereto agree that the court making such determination shall have the power to limit the term or provision, to delete specific words or phrases, or to replace any invalid or unenforceable term or provision with a term or provision that is valid and enforceable and that comes closest to expressing the intention of the invalid or unenforceable term or provision, and this Agreement shall be enforceable as so modified. In the event such court does not exercise the power granted to it in the prior sentence, the parties hereto agree to replace such invalid or unenforceable term or provision with a valid and enforceable term or provision that will achieve, to the extent possible, the economic, business and other purposes of such invalid or unenforceable term.

(i) Specific Performance. The parties hereto agree that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with their specific terms or were otherwise breached. It is accordingly agreed that the parties shall be entitled to an injunction or injunctions to prevent breaches of this Agreement and to enforce specifically the terms and provisions of this Agreement, this being in addition to any other remedy to which they are entitled at law or in equity.

(j) Notices. All notices and other communications hereunder shall be in writing and shall be deemed given if delivered personally or sent by overnight courier (providing proof of delivery), by facsimile transmission (providing confirmation of transmission) or by electronic transmission (upon confirmation of receipt of transmission) to the Company or Parent, as the case may be, in accordance with Section 10.5 of the Merger Agreement and to each Stockholder at his, her or its address or email address (upon confirmation of receipt of transmission) set forth on Appendix A attached hereto (or at such other address for a party as shall be specified by like notice).

Page 6

(k) Counterparts. This Agreement may be executed in two or more counterparts (including by facsimile, by an electronic scan delivered by electronic mail or any electronic signature), each of which shall be deemed an original but all of which together shall be considered one and the same agreement and shall become effective when counterparts have been signed by each of the parties hereto and delivered to the other parties, it being understood that all parties need not sign the same counterpart. This Agreement may be executed and delivered by facsimile, by an electronic scan delivered by electronic mail or by delivery of any electronic signature.

(l) Confidentiality. Except to the extent required by applicable Law or regulation, the Stockholder shall hold any non-public information regarding this Agreement, the Merger Agreement and the Merger in strict confidence and shall not divulge any such information to any third person until Parent has publicly disclosed its entry into the Merger Agreement and this Agreement; provided, however, that the Stockholder may disclose such information to its Affiliates, partners, members, stockholders, parents, subsidiaries, attorneys, accountants, consultants, trustees, beneficiaries and other representatives (provided that such Persons are subject to confidentiality obligations at least as restrictive as those contained herein). Neither the Stockholder nor any of its Affiliates (other than Parent, whose actions shall be governed by the Merger Agreement), shall issue or cause the publication of any press release or other public announcement with respect to this Agreement, the Merger, the Merger Agreement or the other transactions contemplated hereby or thereby without the prior written consent of the Company and Parent, except as may be required by applicable Law in which circumstance such announcing party shall make reasonable efforts to consult with the Company and Parent to the extent practicable. The Company is an intended third-party beneficiary of this Section 10(l).

(m) Further Assurances. Each Stockholder shall, from time to time, execute and deliver, or cause to be executed and delivered, such additional or further consents, documents and other instruments as the Company or Parent may reasonably request for the purpose of effectively carrying out the transactions contemplated by this Agreement and the transactions contemplated by the Merger Agreement.

(n) Disclosure. Each Stockholder hereby agrees that Parent and the Company may publish and disclose in the Registration Statement, any prospectus or registration statement filed with any regulatory authority in connection with the transactions contemplated by the Merger Agreement and any related documents filed with such regulatory authority and as otherwise required by Law, such Stockholder’s identity and ownership of the Shares and the nature of such Stockholder’s commitments, arrangements and understandings under this Agreement and may further file this Agreement as an exhibit to the Registration Statement, prospectus or registration statement or in any other filing made by Parent or the Company as required by Law or the terms of the Merger Agreement, including with the SEC or other regulatory authority, relating to the transactions contemplated by the Merger Agreement. In the event of any such required disclosure, Parent or Company shall use commercially reasonable efforts to provide the Stockholder advance written notice of, and an opportunity to review, any such disclosure that identifies the Stockholder. Prior to the Closing, each Stockholder shall not, and shall use its reasonable best efforts to cause its representatives not to, directly or indirectly, make any press release, public announcement or other public communication with respect to this Agreement, the Merger, the Merger Agreement or the transactions contemplated thereby without the prior written consent of Parent and the Company, provided that the foregoing shall not limit or affect any actions taken by such Stockholder (or any affiliated officer or director of such Stockholder) that would be permitted to be taken by such Stockholder, Parent or the Company pursuant to the Merger Agreement; provided, further, that the foregoing shall not affect any actions of Stockholder the prohibition of which would be prohibited under applicable Law and shall not prohibit Stockholder or its Affiliates from making any publicly-available filings required by applicable law, regulation or legal process.

(o) Fees and Expenses. Except as otherwise specifically provided herein, the Merger Agreement or any other agreement contemplated by the Merger Agreement to which a party hereto is a party, each party hereto shall bear its own expenses in connection with this Agreement and the transactions contemplated hereby.

Page 7

(p) No Ownership Interest. Nothing contained in this Agreement shall be deemed to vest in the Company or Parent any direct or indirect ownership or incidence of ownership of or with respect to any Shares. All rights, ownership and economic benefits of and relating to the Shares shall remain vested in and belong to such Stockholder, and neither the Company nor Parent has authority to manage, direct, superintend, restrict, regulate, govern, or administer any of the policies or operations of Parent or exercise any power or authority to direct such Stockholder in the voting of any of the Shares, except as otherwise provided herein.

(q) Interpretation. When reference is made in this Agreement to a Section or Appendix, such reference shall be to a Section of or Appendix to this Agreement, unless otherwise indicated. The headings contained in this Agreement are for convenience of reference only and shall not affect in any way the meaning or interpretation of this Agreement. The language used in this Agreement shall be deemed to be the language chosen by the parties hereto to express their mutual intent, and no rule of strict construction shall be applied against any party. Whenever the context may require, any pronouns used in this Agreement shall include the corresponding masculine, feminine or neuter forms, and the singular form of nouns and pronouns shall include the plural, and vice versa. Any reference to any federal, state, local or foreign statute or law shall be deemed also to refer to all rules and regulations promulgated thereunder, unless the context requires otherwise. Whenever the words “include,” “includes” or “including” are used in this Agreement, they shall be deemed to be followed by the words “without limitation.”

(r) Adjustments. In the event of any stock split, stock dividend or distribution, merger, reorganization, recapitalization, reclassification, combination, exchange of shares or the like of the capital stock of Parent affecting the Shares, the terms of this Agreement shall apply to the resulting securities.

[Remainder of Page Left Intentionally Blank]

Page 8

IN WITNESS WHEREOF, the undersigned have caused this Agreement to be duly executed as of the date first above written.

COMPANY:

Kalaris Therapeutics, Inc.

By:

Title:

PARENT:

AlloVir, Inc.

By:

Title:

[STOCKHOLDER],

in his/her capacity as the Stockholder:

Signature:

Address: