Exhibit 10.1

CONTINGENT VALUE RIGHTS AGREEMENT

THIS CONTINGENT VALUE RIGHTS AGREEMENT (this “Agreement”), dated as of June 20, 2024, is entered into by and among AVROBIO, Inc., a Delaware corporation (the “Company”) and Computershare Inc., a Delaware corporation, (“Computershare”) and its affiliate Computershare Trust Company, N.A., a federally chartered trust company, jointly as rights agent (collectively, the “Rights Agent”).

RECITALS

WHEREAS, the Company, Alpine Merger Subsidiary, Inc., a Delaware corporation and wholly-owned subsidiary of the Company (“Merger Sub”), and Tectonic Therapeutic, Inc., a Delaware corporation (“Tyrol”), have entered into an Agreement and Plan of Merger and Reorganization, dated as of January 29, 2024 (the “Merger Agreement”), pursuant to which Merger Sub will merge with and into Tyrol, with Tyrol surviving the Merger as a wholly-owned subsidiary of the Company;

WHEREAS, pursuant to the Merger Agreement, and in accordance with the terms and conditions thereof, the Company has agreed to provide to the Holders (as defined herein) contingent value rights as hereinafter described; and

WHEREAS, the parties have done all things reasonably necessary to make the contingent value rights, when issued pursuant to the Merger Agreement and hereunder, the valid obligations of the Company and to make this Agreement a valid and binding agreement of the Company, in accordance with its terms.

NOW, THEREFORE, in consideration of the premises and the consummation of the transactions referred to above, it is mutually covenanted and agreed, for the proportionate benefit of all Holders, as follows:

ARTICLE 1

DEFINITIONS

Section 1.1 Definitions. Capitalized terms used but not otherwise defined herein have the meanings ascribed thereto in the Merger Agreement. The following terms have the meanings ascribed to them as follows:

“Acting Holders” means, at the time of determination, the Holders of more than 30% of the outstanding CVRs, as reflected on the CVR Register.

“Assignee” has the meaning set forth in Section 7.5.

“Calendar Quarter” means the successive periods of three (3) consecutive calendar months ending on March 31, June 30, September 30 or December 31, for so long as this Agreement is in effect; provided, however that (a) the first Calendar Quarter shall commence on the date of this Agreement and shall end on the first such occurrence of a March 31, June 30, September 30 or December 31 thereafter, and (b) the last Calendar Quarter shall commence on the first day after the full Calendar Quarter immediately preceding the effective date of the termination or expiration of this Agreement and shall end on the effective date of the termination or expiration of this Agreement.

“Commercially Reasonable Efforts” means with respect to the disposition of the Company Pre-Closing Assets, carrying out those obligations and tasks in good faith following receipt of a bona fide indication of interest or proposal from a third party (verbal (provided that any such verbal offer must be subsequently delivered in writing, which the Company shall request) or written) (“Inbound Interest”) delivered or otherwise made known to an executive officer or business development officer of the Company, taking into account all commercial and other relevant factors that the Company, exercising good faith, would normally take into account with respect to a disposition of assets; provided that Commercially Reasonable Efforts shall not require the Company to initiate any bona fide sale process or other proactive efforts to identify potential counterparties with respect to any Company Pre-Closing Assets.

“Common Stock” means the common stock, $0.0001 par value, of the Company.

“Company Pre-Closing Assets” means those assets of the Company, to the extent existing as of immediately prior to the Closing, relating to (a) the Company’s plato manufacturing platform, (b) the Company’s AVR-RD-01 (Fabry), AVR-RD-02 (Gaucher), and/or AVR-RD-03 (Pompe) research and development programs, and (c) the Company’s Intellectual Property set forth in Section 4.12(a) of the Aspen Disclosure Schedule.

“CVR” means a contingent contractual right of Holders to receive CVR Payments pursuant to the Merger Agreement and this Agreement.

“CVR Payment” means a cash payment equal to eighty percent (80%) of the Net Proceeds received by the Company in a given Calendar Quarter during the CVR Term, with the remaining twenty percent (20%) being retained by the Company.

“CVR Payment Amount” means with respect to each CVR Payment and each Holder, an amount equal to such CVR Payment divided by the total number of CVRs and then multiplied by the total number of CVRs held by such Holder as reflected on the CVR Register.

“CVR Payment Period” means a period equal to a Calendar Quarter ending at any time after the effective date of a Disposition Agreement.

“CVR Payment Statement” means, for a given CVR Payment Period during the CVR Term, a written statement of the Company, signed on behalf of the Company, setting forth in reasonable detail the calculation of the applicable CVR Payment for such CVR Payment Period.

“CVR Register” has the meaning set forth in Section 2.3(b).

“CVR Term” means the period beginning on the Closing and ending upon the tenth (10^th) anniversary of this Agreement.

“Disposition” or “Dispose” means the direct or indirect sale, license, assignment, transfer, conveyance, grant of any option or other disposition of any Company Pre-Closing Asset by the Company or its Affiliates (including any such sale or disposition of equity securities in any Subsidiary established by the Company or its Affiliates to hold any right, title or interest in or to any Company Pre-Closing Asset), in each case, during the Disposition Period.

“Disposition Agreement” means a definitive written agreement providing for a transaction or series of transactions between the Company or its Affiliates and any Person who is not an Affiliate of the Company regarding a Disposition of the Company Pre-Closing Assets.

“Disposition Period” means the period beginning on the execution date of the Merger Agreement and ending on the date that is eighteen (18) months after the Closing Date.

“DTC” means The Depository Trust Company.

“Funds” has the meaning set forth in Section 7.13.

“Gross Proceeds” means, without duplication, the sum of all cash consideration and the value of any marketable consideration actually received by the Company or any of its Affiliates during the CVR Term with respect to a Disposition, solely as such consideration relates to a Company Pre-Closing Asset. The value of any marketable securities (whether debt or equity) or other non-cash property constituting Gross Proceeds shall be determined as follows: (i) if a value was ascribed to any such securities or property in connection with such Disposition, such value so ascribed or (ii) if no value was ascribed, then (A) the value of securities for which there is an established public market shall be equal to the volume weighted average of their closing market prices for the thirty (30) trading days ending the day prior to the date of payment to, or receipt by the Company or its relevant Affiliate, and (B) the value of securities that have no established public market and the value of consideration that consists of other non-cash property, shall be the fair market value thereof as of the date of payment to, or receipt by, the Company or its relevant Affiliate.

“Holder” means, at the relevant time, a Person in whose name CVRs are registered in the CVR Register.

“Loss” has the meaning set forth in Section 3.2(g).

“Net Proceeds” means, for any CVR Payment Period, Gross Proceeds minus Permitted Deductions, all as calculated, to the extent in accordance with GAAP, in a manner consistent with the Company’s accounting practices in the most recently filed annual audited financial statements with the SEC, except as otherwise set forth herein. For clarity, to the extent Permitted Deductions exceed Gross Proceeds for any CVR Payment Period, any excess Permitted Deductions shall be applied against Gross Proceeds in subsequent CVR Payment Periods.

“Notice” has the meaning set forth in Section 7.1.

“Officer’s Certificate” means a certificate signed by the chief executive officer and the chief financial officer of the Company, in their respective official capacities.

“Party” means the Company or the Rights Agent.

“Permitted Deductions” means the sum of (without duplication):

(a) any applicable Tax (including any applicable value added, transfer, stamp or sales taxes) imposed on Gross Proceeds and payable by Tyrol, the Company or any of their respective Affiliates (regardless of whether the due date for such Taxes arises during or after the Disposition Period) and, without duplication, any income or other similar Taxes payable by Tyrol, the Company or any of their respective Affiliates that would not have been incurred by Tyrol, the Company or any of their respective Affiliates but for the Gross Proceeds; provided that, for purposes of calculating income Taxes incurred by Tyrol, the Company or any of their respective Affiliates in respect of the Gross Proceeds, any such income Taxes shall be computed (i) assuming that the only items of gross income of Tyrol, the Company and their subsidiaries are the applicable items of Gross Proceeds (for the avoidance of doubt, assuming that such items of Gross Proceeds are taxable in the hands of Tyrol, the Company or their subsidiaries, as applicable, no later than the taxable year that includes the corresponding CVR Payment Amount), (ii) assuming that the only items of expenses, losses, credits or other deductions of Tyrol, the Company and their subsidiaries are those items of expense, loss, credit and deduction (including net operating loss carryforwards or other Tax attributes) of the Company or its Affiliates existing as of immediately prior to the Closing for U.S. federal income tax purposes and applicable state and local income tax purposes that are actually usable by Tyrol, the Company or their subsidiaries, as applicable, in the tax year of receipt of the applicable items of Gross Proceeds, to the extent such net operating loss carryforwards and other items are permitted by Law to be, and are, taken as a deduction in such taxable year (for the sake of clarity, (1) taking into account any limits on the usability of such attributes, including under Section 382 of the Code as determined by the Company’s tax advisers, including, but not limited to, as a result of the transactions contemplated by the Merger Agreement and (2) excluding any net operating losses or other Tax attributes generated by Tyrol, the Company or any of their respective Affiliates after the Closing, including by reason of any acquisition after the Closing), and (iii) all such items of Gross Proceeds are taxed in the hands of Tyrol, the Company or their subsidiaries, as applicable, at the highest applicable marginal income or other similar U.S. federal, state, local and non-U.S. tax rate;

(b) any reasonable and documented out-of-pocket costs and expenses incurred by the Company or any of its Affiliates in respect to its performance of this Agreement following the Closing, including any costs related to the prosecution, maintenance or enforcement by the Company or any of its Subsidiaries of intellectual property rights (but excluding any costs related to a breach of this Agreement, including costs incurred in litigation in respect of the same);

(c) any reasonable and documented out-of-pocket expenses incurred or accrued by the Company or any of its Affiliates in connection with the negotiation, entry into and closing of any Disposition of any Company Pre-Closing Asset, including any brokerage fee, finder’s fee, opinion fee, success fee, transaction fee, service fee or other fee, commission or expense owed to any broker, finder, investment bank, auditor, accountant, counsel, advisor or other third party in relation thereto;

(d) (i) any Losses actually incurred, and actually paid or actually payable, or reasonably expected to be incurred and subsequently actually paid by the Company or any of its Subsidiaries arising out of any third-party claims, demands, actions, or other proceedings related to or in connection with any Disposition or any Company Pre-Closing Assets and, without duplication, (ii) an amount that would reasonably be payable under any obligations of the Company or any of its Subsidiaries in respect of contingent or indemnification obligations provided for in any Disposition Agreement; provided that any amounts deducted pursuant to this clause (d) shall be held back by the Company in a separate account for the benefit of the Holders and to the extent such amounts have not been paid in respect of such third-party proceedings or such contingent or indemnification obligations (as applicable) upon the final resolution of such third-party proceedings or the lapse in survival of such contingent or indemnification obligations (provided that in the case of contingent or indemnification obligations that continue indefinitely pursuant to their terms, such lapse of survival shall be deemed to have occurred three (3) years after the commencement of such obligations) (as applicable), in each case prior to the end of the CVR Term, then such amounts shall be paid over to the Rights Agent within fifteen (15) Business Days of such final resolution or such lapse (as applicable) for further distribution to the Holders; and

(e) any proceeds in consideration for a Disposition pursuant to a Disposition Agreement included in the final determination of Aspen Net Cash in accordance with the Merger Agreement.

“Permitted Transfer” means a transfer of CVRs (a) upon death of a Holder by will or intestacy; (b) pursuant to a court order; (c) by operation of Law (including by consolidation or merger) or without consideration in connection with the dissolution, liquidation or termination of any corporation, limited liability company, partnership or other entity; (d) in the case of CVRs held in book-entry or other similar nominee form, from a nominee to a beneficial owner and, if applicable, through an intermediary, to the extent allowable by DTC; or (e) as provided in Section 2.6.

“Rights Agent” means the Rights Agent named in the first paragraph of this Agreement, until a successor Rights Agent will have become the Rights Agent pursuant to the applicable provisions of this Agreement, and thereafter “Rights Agent” will mean such successor Rights Agent.

ARTICLE 2

CONTINGENT VALUE RIGHTS

Section 2.1 Holders of CVRs; Appointment of Rights Agent.

(a) The CVRs represent the rights of Holders to receive CVR Payments pursuant to this Agreement. The initial Holders will be the holders of issued and outstanding shares of Common Stock as of immediately prior to the Effective Time (the “Specified Time”) (including, for the avoidance of doubt, those shares of Common Stock issued upon settlement of Aspen Restricted Stock Units pursuant to Section 6.7 of the Merger Agreement) (the “Eligible Holders” and such shares, the “Eligible Shares”). One CVR will be issued with respect to each Eligible Share.

(b) The Company hereby appoints the Rights Agent to act as Rights Agent for the Company in accordance with the express terms and conditions set forth in this Agreement (and no implied terms and conditions), and the Rights Agent hereby accepts such appointment.

Section 2.2 Non-transferable. The CVRs may not be sold, assigned, transferred, pledged, encumbered or in any other manner transferred or disposed of, in whole or in part, other than through a Permitted Transfer. The CVRs will not be listed on any quotation system or traded on any securities exchange. Any purported transfer of a CVR other than in a Permitted Transfer shall be null and void ab initio.

Section 2.3 No Certificate; Registration; Registration of Transfer; Change of Address.

(a) The CVRs will be issued in book-entry form only and will not be evidenced by a certificate or other instrument.

(b) The Rights Agent shall create and maintain a register (the “CVR Register”) for the purpose of registering CVRs and Permitted Transfers. The CVR Register will be created, and CVRs will be distributed, pursuant to written instructions to the Rights Agent from the Company. The CVR Register will initially show one position for Cede & Co. representing Eligible Shares held by DTC on behalf of the street holders of the Eligible Shares held by such Eligible Holders as of the Specified Time. The Rights Agent will have no responsibility whatsoever directly or indirectly to the street name holders with respect to transfers of CVRs. With respect to any payments or issuances to be made under Section 2.4 below, the Rights Agent will accomplish the payment to any former street name holders of Eligible Shares by sending one lump-sum payment or issuance to DTC. The Rights Agent will have no responsibilities whatsoever with regard to the distribution of payments or Eligible Shares by DTC to such street name holders.

(c) Subject to the restrictions on transferability set forth in Section 2.2, every request made to transfer a CVR must be in writing and accompanied by a written instrument of transfer and any other requested documentation in form reasonably satisfactory to the Rights Agent pursuant to its guidelines or procedures, including a guaranty of signature by an “eligible guarantor institution” that is a member or participant in the Securities Transfer Agents Medallion Program, duly executed and properly completed by the Holder thereof, the Holder’s attorney duly authorized in writing, the Holder’s personal representative or the Holder’s survivor, and setting forth in reasonable detail the circumstances relating to the transfer. Upon receipt of such written notice, the Rights Agent shall, subject to its reasonable determination that the transfer instrument is in proper form and the transfer otherwise complies with the other terms and conditions of this Agreement (including the provisions of Section 2.2), register the transfer of the CVRs in the CVR Register. The Company and Rights Agent may require evidence of payment of a sum sufficient to cover any stamp, documentary, registration, or other Tax or governmental charge that is imposed in connection with any such registration of transfer (or evidence that such Taxes and charges are not applicable). The Rights Agent shall have no duty or obligation to take any action under any section of this Agreement that requires the payment by a Holder of a CVR of applicable taxes or charges unless and until the Rights Agent is satisfied that all such taxes or charges have been paid. All duly transferred CVRs registered in the CVR Register will be the valid obligations of the Company and will entitle the transferee to the same benefits and rights under this Agreement as those held immediately prior to the transfer by the transferor. No transfer of a CVR will be valid until registered in the CVR Register, and any transfer not duly registered in the CVR Register will be void and invalid. All costs and expenses related to any transfer or assignment of the CVRs (including the cost of any transfer tax) will be the responsibility of the transferor.

(d) A Holder may make a written request to the Rights Agent to change such Holder’s address of record in the CVR Register. The written request must be duly executed by the Holder. Upon receipt of such written notice, the Rights Agent shall, subject to its reasonable determination that the transfer instrument is in proper form, promptly record the change of address in the CVR Register. The Acting Holders may, without duplication, make a written request to the Rights Agent for a list containing the names, addresses and number of CVRs of the Holders that are registered in the CVR Register. Upon receipt of such written request from the Acting Holders, the Rights Agent shall promptly deliver a copy of such list to the Acting Holders.

(e) The Company will provide written instructions to the Rights Agent for the distribution of CVRs to Eligible Holders as of the Specified Time. Subject to the terms and conditions of this Agreement and the Company’s prompt confirmation of the Effective Time, the Rights Agent shall effect the distribution of the CVRs, less any applicable tax withholding, to each Eligible Holder as of the Specified Time by the mailing of a statement of holding reflecting such CVRs.

Section 2.4 Payment Procedures.

(a) No later than forty-five (45) days following the end of each Calendar Quarter during the CVR Term, commencing with the first CVR Payment Period in which the Company or its Affiliates receives Gross Proceeds, the Company shall deliver to the Rights Agent a CVR Payment Statement for the such CVR Payment Period. Subject to the last sentence of this Section 2.4(a), concurrent with the delivery of each CVR Payment Statement, on the terms and conditions of this Agreement, the Company shall pay the Rights Agent in U.S. dollars an amount equal to the CVR Payment for the applicable CVR Payment Period. Such CVR Payment will be transferred by wire transfer of immediately available funds to an account designated in writing by the Rights Agent not less than twenty (20) Business Days prior to the date of the applicable payment. Upon receipt of the wire transfer referred to in the foregoing sentence, the Rights Agent shall promptly (and in any event, within ten (10) Business Days) pay, by check mailed, first-class postage prepaid, to the address each Holder set forth in the CVR Register at such time or by other method of deliver as specified by the applicable Holder in writing to the Rights Agent, an amount equal to such Holder’s CVR Payment Amount. The Rights Agent shall as soon as practicable after receipt of a CVR Payment Statement under this Section 2.4(a), send each Holder at its registered address a copy of such statement. For the avoidance of doubt the Company shall have no further liability in respect of the relevant CVR Payment upon delivery of such CVR Payment in accordance with this Section 2.4(a) and the satisfaction of each of the Company’s obligations set forth in this Section 2.4(a). Notwithstanding anything to the contrary herein, no CVR Payment shall become due and payable to any Holder until such time as the then-outstanding and undistributed Net Proceeds exceeds $350,000 in the aggregate.

(b) If instructed by the Company, the Rights Agent shall solicit from each Holder, and each Holder covenants and agrees to provide to the Rights Agent, an IRS Form W-9 or appropriate IRS Form W-8, as applicable, at such time or times, including immediately prior to the first CVR Payment, as is necessary to permit any payment under this Agreement to be made without U.S. federal backup withholding. That notwithstanding, the Company, Tyrol and any of their respective Affiliates (each a “Withholding Agent”) shall be entitled to deduct and withhold and hereby authorizes the Rights Agent to deduct and withhold, any Tax or similar governmental charge or levy, that is required to be deducted or withheld under applicable Law from any amounts payable pursuant to this Agreement. To the extent the amounts are so withheld by a Withholding Agent and paid over to the appropriate Governmental Authority, such withheld amounts shall be treated for all purposes of this Agreement as having been paid to the Person in respect of whom such deduction and withholding was made. The Company will use commercially reasonable efforts to provide withholding and reporting instructions in writing (email being sufficient) to the Rights Agent from time to time as relevant, and upon request of the Rights Agent. The Rights Agent shall have no responsibilities with respect to Tax withholding, reporting or payment except as set forth herein or as specifically instructed by the Company.

(c) Any portion of a CVR Payment that remains undistributed to the Holders six (6) months after the applicable Calendar Quarter end (including by means of uncashed checks or invalid addresses on the CVR Register) will be delivered by the Rights Agent to the Company or a person nominated in writing by the Company (with written notice thereof from the Company to the Rights Agent), and any Holder will thereafter look only to the Company for payment of such CVR Payment (which shall be without interest).

(d) If any CVR Payment (or portion thereof) remains unclaimed by a Holder two (2) years after the applicable Calendar Quarter end (or immediately prior to such earlier date on which such CVR Payment would otherwise escheat to or become the property of any Governmental Authority), such CVR Payment (or portion thereof) will, to the extent permitted by applicable Law, become the property of the Company and will be transferred to the Company or a person nominated in writing by the Company (with written notice thereof from the Company to the Rights Agent), free and clear of all claims or interest of any

Person previously entitled thereto, and no consideration or compensation shall be payable therefor. Neither the Company nor the Rights Agent will be liable to any Person in respect of a CVR Payment delivered to a public official pursuant to any applicable abandoned property, escheat or similar legal requirement under applicable Law. In addition to and not in limitation of any other indemnity obligation herein, the Company agrees to indemnify and hold harmless the Rights Agent with respect to any liability, penalty, cost or expense the Rights Agent may incur or be subject to in connection with transferring such property to the Company, a public office or a person nominated in writing by the Company.

Section 2.5 No Voting, Dividends or Interest; No Equity or Ownership Interest.

(a) If and when issued, the CVRs will not have any voting or dividend rights, and interest will not accrue on any amounts payable in respect of CVRs to any Holder.

(b) If and when issued, the CVRs will not represent any equity or ownership interest in the Company or in any constituent company to the Merger. It is hereby acknowledged and agreed that a CVR shall not constitute a security of the Company.

(c) Nothing contained in this Agreement shall be construed as conferring upon any Holder, by virtue of the CVRs, any rights or obligations of any kind or nature whatsoever as a stockholder or member of the Company or any of its subsidiaries either at Law or in equity. The rights of any Holder and the obligations of the Company and its Affiliates and their respective officers, directors and controlling Persons are contract rights limited to those expressly set forth in this Agreement.

(d) It is hereby acknowledged and agreed that the CVRs and the possibility of any payment hereunder with respect thereto are highly speculative and subject to numerous factors outside of the Company’s control, and there is no assurance that Holders will receive any payments under this Agreement or in connection with the CVRs. Each Holder acknowledges that it is highly possible that no Disposition will occur prior to the expiration of the Disposition Period and that there will not be any Gross Proceeds that may be the subject of a CVR Payment Amount. It is further acknowledged and agreed that neither the Company nor its Affiliates owe, by virtue of their obligations under this Agreement, a fiduciary duty or any implied duties to the Holders and the parties hereto intend solely the express provisions of this Agreement to govern their contractual relationship with respect to the CVRs. It is acknowledged and agreed that this Section 2.5(d) is an essential and material term of this Agreement.

Section 2.6 Ability to Abandon CVR. A Holder may at any time, at such Holder’s option, abandon all of such Holder’s remaining rights represented by CVRs by transferring such CVR to the Company or a Person nominated in writing by the Company (with written notice thereof from the Company to the Rights Agent) without consideration in compensation therefor, and such rights will be cancelled, with the Rights Agent being promptly notified in writing by the Company of such transfer and cancellation. Nothing in this Agreement is intended to prohibit the Company or its Affiliates from offering to acquire or acquiring CVRs, in private transactions or otherwise, for consideration in its sole discretion.

Section 2.7 Intended Tax Treatment. Except to the extent otherwise required by applicable Law, for U.S. federal income tax (and applicable state and local income tax purposes), the parties agree to treat the issuance of the CVRs as not constituting a current distribution and all CVR Payments for all Tax purposes as distributions of money governed by Section 301 of the Code, which will constitute a dividend to the extent payable out of the Company and its Affiliates’ “earnings and profits” (pursuant to Section 316 of the Code) in the taxable year when the CVR Payment is made (the “Intended Tax Treatment”).

ARTICLE 3

THE RIGHTS AGENT

Section 3.1 Certain Duties and Responsibilities.

(a) The Rights Agent will not have any liability for any actions taken , suffered or omitted to be taken in connection with this Agreement, except to the extent such liability arises as a result of the willful misconduct, bad faith, fraud or gross negligence of the Rights Agent (in each case as determined by a final non-appealable judgment of court of competent jurisdiction). Notwithstanding anything in this Agreement to the contrary, any liability of the Rights Agent under this Agreement will be limited to the amount of annual fees paid by the Company to the Rights Agent in connection with this Agreement (but not including reimbursable expenses and other charges) during the twelve (12) months immediately preceding the event for which recovery from the Rights Agent is being sought. Anything to the contrary notwithstanding, in no event will the Rights Agent be liable for special, punitive, indirect, incidental or consequential loss or damages of any kind whatsoever (including, without limitation, lost profits), even if the Rights Agent has been advised of the likelihood of such loss or damages, and regardless of the form of action.

(b) The Rights Agent shall not have any duty or responsibility in the case of the receipt of any written demand from any Holder with respect to any action or default by any person or entity, including, without limiting the generality of the foregoing, any duty or responsibility to initiate or attempt to initiate any Legal Proceedings at Law or otherwise or to make any demand upon the Company or Tyrol. The Rights Agent may (but shall not be required to) enforce all rights of action under this Agreement and any related claim, action, suit, audit, investigation or proceeding instituted by the Rights Agent may be brought in its name as the Rights Agent and any recovery in connection therewith will be for the proportionate benefit of all the Holders, as their respective rights or interests may appear on the CVR Register.

Section 3.2 Certain Rights of Rights Agent.

(a) The Rights Agent undertakes to perform such duties and only such duties as are specifically set forth in this Agreement, and no implied covenants or obligations will be read into this Agreement against the Rights Agent.

(b) The Rights Agent may rely and will be protected and held harmless by the Company in acting or refraining from acting upon any resolution, certificate, statement, instrument, opinion, report, notice, request, direction, consent, order or other paper or document reasonably believed by it to be genuine and to have been signed or presented by or on behalf of the Company or, with respect to Section 2.3(d), the Acting Holders.

(c) Whenever the Rights Agent deems it desirable that a matter be proved or established prior to taking, suffering or omitting to take any action hereunder, the Rights Agent may rely upon an Officer’s Certificate, which certificate shall be full authorization and protection to the Rights Agent, and the Rights Agent shall, in the absence of bad faith, willful misconduct, fraud or gross negligence (in each case as determined by a final non-appealable judgment of court of competent jurisdiction) on its part, not incur any liability and shall be held harmless by the Company for or in respect of any action taken, suffered or omitted to be taken by it under the provisions of this Agreement in reliance upon such Officer’s Certificate.

(d) The Rights Agent may engage and consult with counsel of its selection, and the advice or opinion of such counsel will, in the absence of bad faith, willful misconduct, fraud or gross negligence (in each case as determined by a final non-appealable judgment of court of competent jurisdiction) on the part of the Rights Agent, be full and complete authorization and protection in respect of any action taken, suffered or omitted to be taken by the Rights Agent in the absence of bad faith in reliance thereon.

(e) Any permissive rights of the Rights Agent hereunder will not be construed as a duty.

(f) The Rights Agent will not be required to give any note or surety in respect of the execution of its powers or otherwise under this Agreement.

(g) The Company agrees to indemnify the Rights Agent for, and to hold the Rights Agent harmless from and against, any loss, liability, damage, judgment, fine, penalty, cost, claim, demand, suit or expense (each, a “Loss”) suffered or incurred by the Rights Agent and arising out of or in connection with the Rights Agent’s exercise and performance of its obligations under this Agreement, including the reasonable and documented costs and expenses of defending the Rights Agent against any claims, charges,

demands, actions or suits arising out of or in connection in connection with the execution, acceptance, administration, exercise and performance of its duties under this Agreement, including the costs and expenses of defending against any claim of liability arising therefrom, directly or indirectly, or enforcing its rights hereunder, except to the extent such Loss has been determined by a final non-appealable decision of a court of competent jurisdiction to have resulted from the Rights Agent’s gross negligence, fraud, bad faith or willful misconduct; provided that this Section 3.2(g) shall not apply with respect to income, receipt, franchise or similar Taxes levied against the Rights Agent by a Governmental Authority.

(h) The Company agrees (i) to pay the reasonable, out-of-pocket and documented fees and expenses of the Rights Agent in connection with the Rights Agent’s performance of its obligations hereunder as mutually agreed upon in writing by the Rights Agent and the Company on or prior to the date of this Agreement, and (ii) to reimburse the Rights Agent for all reasonable and documented out-of-pocket expenses and other disbursements incurred in the preparation, delivery, negotiation, amendment, administration and execution of this Agreement and the exercise and performance of its duties hereunder, including all stamp and transfer Taxes (and excluding for the avoidance of doubt, any income, receipt, franchise or similar Taxes levied against the Rights Agent by a Governmental Authority) and governmental charges, incurred by the Rights Agent in the performance of its obligations under this Agreement.

(i) No provision of this Agreement shall require the Rights Agent to expend or risk its own funds or otherwise incur any financial liability in the performance of any of its duties hereunder or in the exercise of any of its rights or powers if it believes that repayment of such funds or adequate indemnification against such risk or liability is not reasonably assured to it.

(j) The Rights Agent shall have no responsibility to the Company, any holders of CVRs, any holders of shares of Common Stock or any other Person for interest or earnings on any moneys held by the Rights Agent pursuant to this Agreement.

(k) The Rights Agent shall not be subject to, nor be required to comply with, or determine if any Person has complied with, the Merger Agreement or any other agreement between or among any the Company, Tyrol or Holders, even though reference thereto may be made in this Agreement, or to comply with any notice, instruction, direction, request or other communication, paper or document other than as expressly set forth in this Agreement.

(l) Subject to applicable Law, (i) the Rights Agent and any shareholder, affiliate, director, officer or employee of the Rights Agent may buy, sell or deal in any securities of the Company or Tyrol or become peculiarly interested in any transaction in which such parties may be interested, or contract with or lend money to such parties or otherwise act as fully and freely as though it were not the Rights Agent under this Agreement, and (ii) nothing herein will preclude the Rights Agent from acting in any other capacity for the Company or for any other Person.

(m) In the event the Rights Agent reasonably believes any ambiguity or uncertainty exists hereunder or in any notice, instruction, direction, request or other communication, paper or document received by the Rights Agent hereunder, the Rights Agent shall, as soon as practicable, provide notice to the Company, and the Rights Agent, may, in its sole discretion, refrain from taking any action, and shall be fully protected and shall not be liable in any way to the Company or any Holder or any other Person for refraining from taking such action, unless the Rights Agent receives written instructions from the Company or such Holder or other Person which eliminate such ambiguity or uncertainty to the reasonable satisfaction of the Rights Agent;

(n) The Rights Agent may execute and exercise any of the rights or powers hereby vested in it or perform any duty hereunder either itself or by or through its attorney or agents and the Rights Agent shall not be answerable or accountable for any act, default, neglect or misconduct of any such attorney or agents or for any loss to the Company or Tyrol resulting from any such act, default, neglect or misconduct, absent gross negligence, fraud, bad faith or willful misconduct (each as determined by a final non-appealable judgment of a court of competent jurisdiction) in the selection and continued employment thereof.

(o) The Rights Agent shall not be liable for or by reason of any of the statements of fact or recitals contained in this Agreement (except its countersignature thereof) or be required to verify the same, and all such statements and recitals are and shall be deemed to have been made by the Company only.

(p) The Rights Agent shall act hereunder solely as agent for the Company and shall not assume any obligations or relationship of agency or trust with any of the owners or holders of the CVRs. The Rights Agent shall not have any duty or responsibility in the case of the receipt of any written demand from any Holders with respect to any action or default by the Company, including, without limiting the generality of the foregoing, any duty or responsibility to initiate or attempt to initiate any Legal Proceedings at Law or otherwise or to make any demand upon the Company.

(q) The Rights Agent may rely on and be fully authorized and protected in acting or failing to act upon (a) any guaranty of signature by an “eligible guarantor institution” that is a member or participant in the Securities Transfer Agents Medallion Program or other comparable “signature guarantee program” or insurance program in addition to, or in substitution for, the foregoing; or (b) any Law, act, regulation or any interpretation of the same even though such Law, act, or regulation may thereafter have been altered, changed, amended or repealed.

(r) The Rights Agent shall not be liable or responsible for any failure of the Company to comply with any of its obligations relating to any registration statement filed with the SEC or this Agreement, including without limitation obligations under applicable regulation or Law.

(s) The obligations of the Company and the rights of the Rights Agent under this Section 3.2, Section 3.1 and Section 2.4 shall survive the expiration of the CVRs and the termination of this Agreement and the resignation, replacement or removal of the Rights Agent.

(t) The Rights Agent will not be deemed to have knowledge of any event of which it was supposed to receive notice hereunder but has not received written notice of such event, and the Rights Agent will not incur any liability for failing to take action in connection therewith, in each case, unless and until it has received such notice in writing.

(u) The Rights Agent will have no liability and shall be held harmless by the Company in respect of the validity of this Agreement and the execution and delivery hereof (except the due execution and delivery hereof by the Rights Agent and the enforceability of this Agreement against the Rights Agent assuming the due execution and delivery hereof by the Company), nor shall it be responsible for any breach by the Company of any covenant or condition contained in this Agreement.

Section 3.3 Resignation and Removal; Appointment of Successor.

(a) The Rights Agent may resign at any time by written notice to the Company. Any such resignation notice shall specify the date on which such resignation will take effect (which shall be at least thirty (30) days following the date that such resignation notice is delivered), and such resignation will be effective on the earlier of (x) the date so specified and (y) the appointment of a successor Rights Agent.

(b) The Company will have the right to remove the Rights Agent at any time by written notice to the Rights Agent, specifying the date on which such removal will take effect. Such notice will be given at least thirty (30) days prior to the date so specified (or, if earlier, the appointment of the successor Rights Agent).

(c) If the Rights Agent resigns, is removed or becomes incapable of acting, the Company will promptly appoint a qualified successor Rights Agent. Notwithstanding the foregoing, if the Company fails to make such appointment within a period of thirty (30) days after giving notice of such removal or after it has been notified in writing of such resignation or incapacity by the resigning or incapacitated Rights Agent, then any Holder may apply to any court of competent jurisdiction for the appointment of a new Rights Agent. The successor Rights Agent so appointed will, upon its acceptance of such appointment in accordance with this Section 3.3(c) and Section 3.4, become the Rights Agent for all purposes hereunder.

(d) The Company will give notice to the Holders of each resignation or removal of the Rights Agent and each appointment of a successor Rights Agent in accordance with Section 7.2. Each notice will include the name and address of the successor Rights Agent. If the Company fails to send such notice within ten (10) Business Days after acceptance of appointment by a successor Rights Agent, the successor Rights Agent will cause the notice to be mailed at the expense of the Company.

(e) Notwithstanding anything to the contrary in this Section 3.3, unless consented to in writing by the Acting Holders, the Company will not appoint as a successor Rights Agent any Person that is not a stock transfer agent of national reputation or the corporate trust department of a commercial bank.

(f) The Rights Agent will reasonably cooperate with the Company and any successor Rights Agent in connection with the transition of the duties and responsibilities of the Rights Agent to the successor Rights Agent, including the transfer of all relevant data, including the CVR Register, to the successor Rights Agent, but such predecessor Rights Agent shall not be required to make any additional expenditure or assume any additional liability in connection with the foregoing.

Section 3.4 Acceptance of Appointment by Successor. Every successor Rights Agent appointed hereunder will, at or prior to such appointment, execute, acknowledge and deliver to the Company and to the resigning or removed Rights Agent an instrument accepting such appointment and a counterpart of this Agreement, and such successor Rights Agent, without any further act, deed or conveyance, will become vested with all the rights, powers, trusts and duties of the Rights Agent; provided that upon the request of the Company or the successor Rights Agent, such resigning or removed Rights Agent will execute and deliver an instrument transferring to such successor Rights Agent all the rights, powers and trusts of such resigning or removed Rights Agent, except such rights which survive its resignation or removal under the terms hereunder.

ARTICLE 4

COVENANTS

Section 4.1 List of Holders. The Company will furnish or cause to be furnished to the Rights Agent, in such form as the Company receives from the Company’s transfer agent (or other agent performing similar services for the Company), the names and addresses of the Holders within fifteen (15) Business Days following the Closing Date.

Section 4.2 Efforts.

(a) During the Disposition Period, the Company shall, and shall cause its Subsidiaries to, use Commercially Reasonable Efforts to effect Dispositions with respect to the Company Pre-Closing Assets to a third party that has delivered Inbound Interest delivered or otherwise made known to an executive officer or business development officer of the Company with respect to a Company Pre-Closing Asset after the Closing to the Company, its Subsidiaries or their Representatives in evaluating or potentially engaging in a Disposition.

(b) Subject to Section 4.2(a) and the other contractual obligations of the Company expressly set forth in this Agreement, (i) the Holders acknowledge that the Company has a fiduciary obligation to operate its business in the best interests of its stockholders, and any potential obligation to pay CVR Payments will not create any express or implied obligation to operate its business in any particular manner in order to maximize such CVR Payments, (ii) except as expressly set forth in this Agreement, the Holders are not relying on any representation of the Company or any other Person with regard to any Disposition or other action involving the Company Pre-Closing Assets following the Closing, and neither the Company nor any other Person has provided, or can provide, any assurance to the Holders that any CVR Payments will in fact be earned and paid, and (iii) none of the Company or any of its Subsidiaries, officers or directors shall have any obligation or liability whatsoever to any Person relating to or in connection with any action, or failure to act, with respect to any Disposition.

Section 4.3 Additional Covenants. During the Disposition Period:

(a) Without limiting any other provisions of this Section 4.3, neither the Company nor any of its Affiliates shall take any action in bad faith with respect to, or with the primary purpose of avoiding, the payment of the CVR Payment Amount, including by making any dividend, distribution or other transfer of Net Proceeds in a manner materially adverse to the Company’s obligations in respect of Net Proceeds pursuant to this Agreement

(b) The Company shall, and shall cause its subsidiaries to, use commercially reasonable efforts to continue to preserve and maintain the Company Pre-Closing Assets, including all Intellectual Property relating thereto but, and shall use commercially reasonable efforts to comply with such maintenance obligations as required by any license or related term set forth in any Disposition Agreement. Notwithstanding the foregoing, with respect to such efforts to preserve and maintain Intellectual Property relating to the Company Pre-Closing Assets, (A) the Company shall not be required to incur aggregate out-of-pocket costs and expenses in excess of $200,000 (the “IP Expense Fund”) and (B) the Company shall prioritize the application of the IP Expense Fund in accordance with the provisions of Schedule 1 hereto.

(c) The Company shall not grant any lien, security interest, pledge or similar interest in any Company Pre-Closing Assets or any Net Proceeds other than (A) pursuant to the terms of a Disposition Agreement or (B) any such interest generally granted with respect to all assets of the Company and not specific to any of the Company Pre-Closing Assets, and which do not prohibit the ability of the Company to complete a Disposition and, in connection therewith, to deliver title to the Company Pre-Closing Assets to the purchaser thereof, free and clear of such interest.

(d) The Company shall promptly inform the director(s) on the Company board of directors who then hold CVRs if and after Inbound Interest is delivered or otherwise made known to an executive officer or business development officer of the Company, and shall keep such director(s) reasonably and promptly informed regarding material developments in the negotiation of Disposition Agreements.

Section 4.4 Books and Records. Until the end of the CVR Term, the Company shall, and shall cause its Affiliates to, keep true, complete and accurate records in sufficient detail to enable the Rights Agent to confirm the applicable CVR Payment Amount payable hereunder in accordance with the terms specified in this Agreement.

Section 4.5 Audits. Until the expiration of this Agreement and for a period of one (1) year thereafter, the Company shall keep complete and accurate records in sufficient detail to support the accuracy of the payments due hereunder. The Acting Holders shall have the right to cause an independent accounting firm reasonably acceptable to the Company to audit such records for the sole purpose of confirming payments for a period covering not more than the date commencing with the first CVR Payment Period in which the Company or its Affiliates receives Gross Proceeds and ending on the last day of the CVR Term. The Company may require such accounting firm to execute a reasonable confidentiality agreement with the Company prior to commencing the audit. The accounting firm shall disclose to Rights Agent or the Acting Holders, as applicable, only whether the reports are correct or not and the specific details concerning any discrepancies. No other information shall be shared. Such audits may be conducted during normal business hours upon reasonable prior written notice to the Company, but no more than frequently than once per year. No accounting period of the Company shall be subject to audit more than one time by the Acting Holders,

as applicable, unless after an accounting period has been audited by the Acting Holders, as applicable, the Company restates its financial results for such accounting period, in which event the Acting Holders, as applicable, may conduct a second audit of such accounting period in accordance with this Section 4.5. Adjustments (including remittances of underpayments or overpayments disclosed by such audit) shall be made by the Company to reflect the results of such audit, which adjustments shall be paid promptly following receipt of an invoice therefor. Whenever such an adjustment is made, the Company shall promptly prepare a certificate setting forth such adjustment, and a brief, reasonably detailed statement of the facts, computation and methodology accounting for such adjustment to the extent not already reflected in the audit report and promptly file with the Rights Agent a copy of such report and promptly deliver to the Rights Agent a revised CVR Payment Statement for the relevant CVR Payment Period. The Rights Agent shall be fully protected in relying on any such report and on any adjustment or statement therein contained and shall have no duty or liability with respect to, and shall not be deemed to have knowledge of any such adjustment or any such event unless and until it shall have received such report. The Acting Holders, as applicable, shall bear the full cost and expense of such audit unless such audit discloses an underpayment by the Company of twenty percent (20%) or more of the CVR Payment Amount due under this Agreement, in which case the Company shall bear the full cost and expense of such audit. The Rights Agent shall be entitled to rely on any audit report delivered by the independent accounting firm pursuant to this Section 4.5.

Section 4.7 No Conflict. The Company will not enter into any agreement with any Person that is, or otherwise take any actions or inactions, in conflict with this Agreement in any material respect or materially and adversely affect the performance of its obligations under this Agreement.

ARTICLE 5

AMENDMENTS

Section 5.1 Amendments Without Consent of Holders.

(a) The Company, at any time and from time to time, may (without the consent of any Person, other than the Rights Agent, with such consent not to be unreasonably withheld, conditioned or delayed) enter into one or more amendments to this Agreement for any of the following purposes:

(i) to evidence the appointment of another Person as a successor Rights Agent and the assumption by any successor Rights Agent of the covenants and obligations of the Rights Agent herein in accordance with the provisions hereof;

(ii) subject to Section 6.1, to evidence the succession of another person to the Company and the assumption of any such successor of the covenants of the Company outlined herein in a transaction contemplated by Section 6.1;

(iii) to add to the covenants of the Company such further covenants, restrictions, conditions or provisions as the Company and the Rights Agent will consider to be for the protection and benefit of the Holders; provided that in each case, such provisions do not adversely affect the interests of the Holders;

(iv) to cure any ambiguity, to correct or supplement any provision in this Agreement that may be defective or inconsistent with any other provision in this Agreement, or to make any other provisions with respect to matters or questions arising under this Agreement; provided that, in each case, such provisions do not adversely affect the interests of the Holders;

(v) as may be necessary or appropriate to ensure that the CVRs are not subject to registration under the Securities Act or the Exchange Act and the rules and regulations promulgated thereunder, or any applicable state securities or “blue sky” laws;

(vi) as may be necessary or appropriate to ensure that the Company is not required to produce a prospectus or an admission document in order to comply with applicable Law;

(vii) to cancel the CVRs (i) in the event that any Holder has abandoned its rights in accordance with Section 2.6, (ii) in order to give effect to the provisions of Section 2.7 or (iii) following a transfer of such CVRs to the Company or its Affiliates in accordance with Section 2.2 or Section 2.3;

(viii) as may be necessary or appropriate to ensure that the Company complies with applicable Law; or

(ix) to effect any other amendment to this Agreement for the purpose of adding, eliminating or changing any provisions of this Agreement, provided that, in each case, such additions, eliminations or changes do not adversely affect the interests of the Holders.

(b) Promptly after the execution by the Company of any amendment pursuant to this Section 5.1, the Company will (or will cause the Rights Agent to) notify the Holders in general terms of the substance of such amendment in accordance with Section 7.2.

Section 5.2 Amendments with Consent of Holders.

(a) In addition to any amendments to this Agreement that may be made by the Company without the consent of any Holder pursuant to Section 5.1, with the consent of the Acting Holders (whether evidenced in a writing or taken at a meeting of the Holders), the Company and the Rights Agent may enter into one or more amendments to this Agreement for the purpose of adding, eliminating or amending any provisions of this Agreement, even if such addition, elimination or amendment is adverse to the interests of the Holders.

(b) Promptly after the execution by the Company and the Rights Agent of any amendment pursuant to the provisions of this Section 5.2, the Company will (or will cause the Rights Agent to) notify the Holders in general terms of the substance of such amendment in accordance with Section 7.2.

Section 5.3 Effect of Amendments.

Upon the execution of any amendment under this Article 5, this Agreement will be modified in accordance therewith, such amendment will form a part of this Agreement for all purposes and every Holder will be bound thereby. Upon the delivery of a certificate from an appropriate officer of the Company which states that the proposed supplement or amendment is in compliance with the terms of this Section 5, the Rights Agent shall execute such supplement or amendment. Notwithstanding anything in this Agreement to the contrary, the Rights Agent shall not be required to execute any supplement or amendment to this Agreement that it has determined would adversely affect its own rights, duties, obligations or immunities under this Agreement. No supplement or amendment to this Agreement shall be effective unless duly executed by the Rights Agent.

ARTICLE 6

CONSOLIDATION, MERGER, SALE OR CONVEYANCE

Section 6.1 The Company May Not Consolidate, Etc. During the CVR Term, the Company shall not consolidate with or merge into any other Person or convey, transfer or lease its properties and assets substantially as an entirety to any Person, unless:

(a) the Person formed by such consolidation or into which the Company is merged or the Person that acquires by conveyance or transfer, or that leases, the properties and assets of the Company substantially as an entirety (the “Surviving Person”) shall expressly assume payment of amounts on all CVRs (when and as due hereunder) and the performance of every duty and covenant of this Agreement on the part of the Company to be performed or observed; and

(b) The Company has delivered to the Rights Agent an Officer’s Certificate, stating that such consolidation, merger, conveyance, transfer or lease complies with this Article 6 and that all conditions precedent herein provided for relating to such transaction have been complied with.

Section 6.2 Successor Substituted. Upon any consolidation of or merger by the Company with or into any other Person, or any conveyance, transfer or lease of the properties and assets substantially as an entirety to any Person in accordance with Section 6.3, the Surviving Person shall succeed to, and be substituted for, and may exercise every right and power of, and shall assume all of the obligations of the Company under this Agreement with the same effect as if the Surviving Person had been named as the Company herein.

ARTICLE 7

MISCELLANEOUS

Section 7.1 Notices to Rights Agent and to the Company. All notices, requests and other communications (each, a “Notice”) to any party hereunder shall be in writing and shall be deemed to have been duly delivered and received hereunder (a) when sent, fees prepaid, via a reputable international overnight courier service in the case of delivery in person, by FedEx or other internationally recognized overnight courier service or (b) (except in the case of the Rights Agent) when sent, if sent by email (with a written or electronic confirmation of delivery) prior to 6:00 p.m. (New York City time), otherwise on the next succeeding Business Day, in each case to the intended recipient as set forth below:

if to the Rights Agent, to:

Computershare Trust Company, N.A.,

Computershare Inc.

150 Royall Street

Canton, MA 02021

Attention: Client Services

Facsimile: (781) 575-4210

if to the Company, to:

Tectonic Therapeutic, Inc.

400 Arsenal Way, Suite 210

Watertown, MA 02472

Attention: Alise Reicin, Chief Executive Officer

Email: areicin@tectonictx.com

with a copy, which shall not constitute notice, to:

Cooley LLP

500 Boylston Street

Boston, MA 02116

Attention: Miguel Vega; Marc Recht; Michael Rohr

E-mail: mvega@cooley.com; mrecht@cooley.com; mrohr@cooley.com

or to such other address as such party may hereafter specify for the purpose by notice to the other parties hereto.

Section 7.2 Notice to Holders. All Notices required to be given to the Holders will be given (unless otherwise herein expressly provided) in writing and mailed, first-class postage prepaid, to each Holder at such Holder’s address as set forth in the CVR Register, not later than the latest date, and not earlier than the earliest date, prescribed for the sending of such Notice, if any, and will be deemed given on the date of mailing. In any case where notice to the Holders is given by mail, neither the failure to mail such Notice, nor any defect in any Notice so mailed, to any particular Holder will affect the sufficiency of such Notice with respect to other Holders.

Section 7.3 Entire Agreement. As between the Company and the Rights Agent, this Agreement constitutes the entire agreement between the parties with respect to the subject matter of this Agreement, notwithstanding the reference to any other agreement herein, and supersedes all prior agreements and understandings, both written and oral, among or between any of the parties with respect to the subject matter of this Agreement. If and to the extent that any provision of this Agreement is inconsistent or conflicts with the Merger Agreement, this Agreement will govern and be controlling.

Section 7.4 Merger or Consolidation or Change of Name of Rights Agent. Any Person into which the Rights Agent or any successor Rights Agent may be merged or with which it may be consolidated, or Person resulting from any merger or consolidation to which the Rights Agent or any successor Rights Agent shall be a party, or any Person succeeding to the stock transfer or other shareholder services business of the Rights Agent or any successor Rights Agent, shall be the successor to the Rights Agent under this Agreement without the execution or filing of any paper or any further act on the part of any of the parties hereto, provided that such Person would be eligible for appointment as a successor Rights Agent under the provisions of Section 3.3. The purchase of all or substantially all of the Rights Agent’s assets employed in the performance of transfer agent activities shall be deemed a merger or consolidation for purposes of this Section 7.4.

Section 7.5 Successors and Assigns. This Agreement will be binding upon, and will be enforceable by and inure solely to the benefit of, the Holders, the Company and the Rights Agent and their respective successors and assigns. Except for assignments pursuant to Section 7.4, the Rights Agent may not assign this Agreement without the Company’s prior written consent. Subject to Section 5.1(a)(ii) and Article 6 hereof, the Company may assign, in its sole discretion and without the consent of any other party, any or all of its rights, interests and obligations hereunder to one or more of its Affiliates or to any Person with whom the Company is merged or consolidated, or any entity resulting from any merger or consolidation to which the Company shall be a party (each, an “Assignee”); provided, that in connection with any assignment to an Assignee, the Company shall agree to remain liable for the performance by the Company of its obligations hereunder (to the extent the Company exists following such assignment). The Company or an Assignee may not otherwise assign this Agreement without the prior consent of the Acting Holders (such consent not to be unreasonably withheld, conditioned or delayed). Any attempted assignment of this Agreement in violation of this Section 7.5 will be void ab initio and of no effect.

Section 7.6 Benefits of Agreement; Action by Acting Holders. Nothing in this Agreement, express or implied, will give to any Person (other than the Company, the Rights Agent, the Holders and their respective permitted successors and assigns hereunder) any benefit or any legal or equitable right, remedy or claim under this Agreement or under any covenant or provision herein contained, all such covenants and provisions being for the sole benefit of the Company, the Rights Agent, the Holders and their permitted successors and assigns. The Holders will have no rights hereunder except as are expressly set forth herein. The Holders shall be intended third-party beneficiaries of the provisions of this Agreement; provided that, except for the rights of the Rights Agent set forth herein, the Acting Holders will have the sole right, on behalf of all Holders, by virtue of or under any provision of this Agreement, to institute any action or Legal Proceeding at Law or in equity with respect to this Agreement or otherwise to enforce the Holders’ rights hereunder, and no individual Holder or other group of Holders will be entitled to exercise such rights.

Section 7.7 Governing Law. This Agreement and the CVRs will be governed by, and construed in accordance with, the laws of the State of Delaware without regard to the conflicts of law rules of such state.

Section 7.8 Jurisdiction. In any action or proceeding between any of the parties hereto arising out of or relating to this Agreement or any of the transactions contemplated hereby, each of the parties hereto: (a) irrevocably and unconditionally consents and submits to the exclusive jurisdiction and venue of the Court of Chancery of the State of Delaware or, to the extent such court does not have subject matter jurisdiction, the Superior Court of the State of Delaware or the United States District Court for the District of Delaware, and appellate courts thereof; (b) agrees that all claims in respect of such action or proceeding shall be heard and determined exclusively in accordance with clause (a) of this Section 7.8; (c) waives any objection to laying venue in any such action or proceeding in such courts; (d) waives any objection that such courts are an inconvenient forum or do not have jurisdiction over any Party; and (e) agrees that service of process upon such Party in any such action or proceeding shall be effective if notice is given in accordance with Section 7.1 or Section 7.2 of this Agreement; provided that, nothing in this Section 7.8 shall affect the right of any Party to serve legal process in any other manner permitted by applicable Law.

Section 7.9 WAIVER OF JURY TRIAL. EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR RELATED TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY. EACH PARTY CERTIFIES AND ACKNOWLEDGES THAT (I) NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVER, (II) EACH PARTY UNDERSTANDS AND HAS CONSIDERED THE IMPLICATION OF THIS WAIVER, (III) EACH PARTY MAKES THIS WAIVER VOLUNTARILY, AND (IV) EACH PARTY HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION 7.9.

Section 7.10 Severability Clause. In the event that any provision of this Agreement, or the application of any such provision to any Person or set of circumstances, is for any reason determined to be invalid, unlawful, void or unenforceable to any extent, the remainder of this Agreement, and the application of such provision to Persons or circumstances other than those as to which it is determined to be invalid, unlawful, void or unenforceable, will not be impaired or otherwise affected and will continue to be valid and enforceable to the fullest extent permitted by applicable Law. Upon such a determination, the parties hereto will negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in a mutually acceptable manner in order that the transactions contemplated hereby be consummated as originally contemplated to the fullest extent possible; provided, however, that if an excluded provision shall affect the rights, immunities, liabilities, duties or obligations of the Rights Agent, the Rights Agent shall be entitled to resign immediately upon written Notice to the Company.

Section 7.11 Counterparts; Effectiveness. This Agreement may be signed in any number of counterparts, each of which will be deemed an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Agreement or any counterpart may be executed and delivered by electronic communications by portable document format (.pdf), each of which shall be deemed an original. This Agreement will become effective when each party hereto will have received a counterpart hereof signed by the other party hereto. Until and unless each party has received a counterpart hereof signed by the other party hereto, this Agreement will have no effect and no party will have any right or obligation hereunder (whether by virtue of any oral or written agreement or any other communication).

Section 7.12 Termination. This Agreement will automatically terminate and be of no further force or effect and, except as provided in Section 3.2, the parties hereto will have no further liability hereunder, and the CVRs will expire without any consideration or compensation therefor, upon the expiration of the CVR Term. The termination of this Agreement will not affect or limit the right of Holders to receive the CVR Payments under Section 2.4 to the extent earned prior to the termination of this Agreement, and the provisions applicable thereto will survive the expiration or termination of this Agreement until such CVR Payments have been made, if applicable. Upon termination or expiry of this Agreement pursuant to this Section 7.12, all CVRs issued hereunder shall be automatically cancelled and forfeited by the Holders without any consideration or payment therefor. Notwithstanding the foregoing, no such termination shall affect any rights or obligations accrued prior to the effective date of such termination.

Section 7.13 Funds. All funds received by Computershare under this Agreement that are to be distributed or applied by Computershare in the performance of services hereunder (the “Funds”) shall be held by Computershare, as agent for the Company, and deposited in one or more bank accounts to be maintained by Computershare in its name as agent for the Company. Until paid pursuant to the terms of this Agreement, Computershare may hold or invest the Funds through such accounts in: (a) funds backed by obligations of, or guaranteed by, the United States of America; (b) debt or commercial paper obligations rated A-1 or P-1 or better by S&P Global Inc. (“S&P”) or Moody’s Investors Service, Inc. (“Moody’s”), respectively; (c) Government and Treasury backed AAA-rated Fixed NAV money market funds that comply with Rule 2a-7 of the Investment Company Act of 1940, as amended; or (d) short term certificates of deposit, bank repurchase agreements, and bank accounts with commercial banks with Tier 1 capital exceeding $1 billion, or with an investment grade rating by S&P (LT Local Issuer Credit Rating), Moody’s (Long Term Rating) and Fitch Ratings, Inc. (LT Issuer Default Rating) (each as reported by Bloomberg Finance L.P.). The Rights Agent shall have no responsibility or liability for any diminution of the Funds that may result from any deposit or investment made by Computershare in accordance with this paragraph, including any losses resulting from a default by any bank, financial institution or other third party. Computershare may from time to time receive interest, dividends or other earnings in connection with such deposits or investments. The Rights Agent shall not be obligated to pay such interest, dividends or earnings to the Company, any holder or any other party.

Section 7.14 Further Assurance by Company. The Company agrees that it will perform, execute, acknowledge and deliver or cause to be performed, executed, acknowledged and delivered all such further and other acts, instruments and assurances as may reasonably be required or requested by the Rights Agent for the carrying out or performing by the Rights Agent of the provisions of this Agreement.

Section 7.15 Force Majeure. Notwithstanding anything to the contrary contained herein, the Rights Agent will not be liable for any delays or failures in performance resulting from acts beyond its reasonable control including, without limitation, acts of God, epidemic, pandemic, terrorist acts, shortage of supply, breakdowns or malfunctions, interruptions or malfunction of computer facilities, or loss of data due to power failures or mechanical difficulties with information storage or retrieval systems, labor difficulties, war, or civil unrest.

Section 7.16 Construction.

(a) For purposes of this Agreement, whenever the context requires: singular terms will include the plural, and vice versa; the masculine gender will include the feminine and neuter genders; the feminine gender will include the masculine and neuter genders; and the neuter gender will include the masculine and feminine genders.

(b) As used in this Agreement, the words “include” and “including,” and variations thereof, will not be deemed to be terms of limitation, but rather will be deemed to be followed by the words “without limitation.”

(c) The headings contained in this Agreement are for convenience of reference only, will not be deemed to be a part of this Agreement and will not be referred to in connection with the construction or interpretation of this Agreement.

(d) Unless stated otherwise, “Article” and “Section” followed by a number or letter mean and refer to the specified Article or Section of this Agreement. The term “Agreement” and any reference in this Agreement to this Agreement or any other agreement or document includes, and is a reference to, this Agreement or such other agreement or document as it may have been, or may from time to time be, amended, restated, replaced, supplemented or novated and includes all schedules to it.

(e) A period of time is to be computed as beginning on the day following the event that began the period and ending at 4:30 p.m. on the last day of the period, if the last day of the period is a Business Day, or at 4:30 p.m. on the next Business Day if the last day of the period is not a Business Day.

(f) Any reference in this Agreement to a date or time shall be deemed to be such date or time in New York City, United States, unless otherwise specified. The parties hereto and the Company have participated jointly in the negotiation and drafting of this Agreement. In the event an ambiguity or question of intent or interpretation arises, this Agreement shall be construed as if drafted jointly by the parties and the Company and no presumption or burden of proof shall arise favoring or disfavoring any Person by virtue of the authorship of any provision of this Agreement.

(g) All references herein to “$” are to United States Dollars.

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IN WITNESS WHEREOF, each of the parties has caused this Agreement to be executed as of the day and year first above written.

AVROBIO, INC.
By:	/s/ Erik Ostrowski
Name:	Erik Ostrowski
Title:	President, Interim Chief Executive Officer, Chief Financial Officer and Treasurer
COMPUTERSHARE INC. and COMPUTERSHARE TRUST COMPANY, N.A., as Rights Agent On behalf of both entities
By:	/s/ Erik Schwendenman
Name:	Erik Schwendenman
Title:	VP Business Development