Exhibit 10.1

FOURTH AMENDMENT TO LEASE

THIS FOURTH AMENDMENT TO LEASE (this “Fourth Amendment”) is made as of this 30 day of September, 2025 (the “Effective Date”), by and between ARE-NC REGION NO. 21, LLC, a Delaware limited liability company (“Landlord”), and ADVERUM NC, LLC, a Delaware limited liability company (“Tenant”).

RECITALS

A.Landlord and Tenant are now parties to that certain Lease Agreement dated as of January 8, 2021 (the “Original Lease”), as amended by that certain letter agreement dated as of January 8, 2021, and as further amended by that certain First Amendment to Lease Agreement dated as of April 15, 2021, that certain Acknowledgment of Commencement Date dated as of April 23, 2021, that certain Consent to Sublease and Second Amendment to Lease dated as of October 26, 2021, that certain Third Amendment to Lease Agreement and First Amendment to Consent to Sublease dated as of April 3, 2023, and that certain letter agreement dated June 6, 2025 (as amended, the “Lease”). Pursuant to the Lease, Tenant leases certain premises consisting of the entire building (the “Premises”) located at 14 TW Alexander Drive, Durham, North Carolina. The Premises is more particularly described in the Lease. Capitalized terms used herein without definition shall have the meanings defined for such terms in the Lease.

B.The Base Term of the Lease is scheduled to expire on October 31, 2037.

C.Landlord and Tenant desire, subject to the terms set forth below, to amend the Lease to, among other things, provide for a contingent early termination of the Lease, as provided in this Fourth Amendment.

NOW, THEREFORE, in consideration of the foregoing Recitals, which are incorporated herein by this reference, the mutual promises and conditions contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree as follows:

1.Lease Contingent Early Termination. Notwithstanding anything contained in the Lease to the contrary, the expiration date of the Lease shall be accelerated (the “Early Termination”) if Landlord signs a new lease with a third party for the Premises (a “New Lease”) or sells the Premises or the Project to a third party. The termination of the Lease shall be effective on the day immediately prior to the date on which (i) Landlord executes a New Lease or (ii) the sale of the Premises or the Project closes (as applicable, the “Trigger Date”). Landlord shall deliver to Tenant a written notice (“Termination Notice”), which may be by email addressed to legal@adverum.com, of the Early Termination no more than 1 business day following the Trigger Date. The “Early Termination Date” shall be the date on which Landlord delivers the Termination Notice. If Landlord timely and properly delivers the Termination Notice, then Tenant shall vacate the Premises and deliver possession thereof to Landlord in substantially the condition required by the terms of the Lease upon receipt of the Termination Notice, and Tenant shall have no further obligations under the Lease after the Early Termination Date except for those accruing prior to the Early Termination Date and those which, pursuant to the terms of the Lease, survive the expiration or early termination of Lease. Notwithstanding anything to the contrary contained in the Lease, so long as Tenant does not cause damage to the Premises following the Effective Date or in connection with Tenant moving out of the Premises, Tenant shall not be required to perform any repair or restoration obligations prior to surrendering the Premises; provided, however, nothing herein shall be deemed to limit or terminate any common law, statutory rights or any other rights Landlord may have against Tenant under the Lease in connection with Hazardous Materials. For the avoidance of doubt, the Promissory Note (as defined in Section 2 below) shall also survive the early termination of the Lease. Tenant acknowledges that nothing contained herein shall obligate Landlord in any way to enter into a New Lease or sell the Premises or the Project.

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2.Lease Modification Payment. In consideration of Landlord’s agreement to enter into this Fourth Amendment, Tenant agrees to deliver to Landlord an amount equal to $7,500,000.00 (the “Lease Modification Payment”), contingent on and subject to the terms and conditions set forth below. The Lease Modification Payment shall be paid as follows:

(a)Concurrently with Tenant’s delivery of an executed copy of this Fourth Amendment to Landlord, Tenant’s parent company, Adverum Biotechnologies, Inc., a Delaware corporation (“Guarantor”), shall execute and deliver to Landlord, a Promissory Note in the principal amount of $7,400,000.00, substantially in the form attached hereto as Exhibit A (the “Promissory Note”), which Promissory Note shall be held in escrow by Landlord and not deemed released to Landlord until the Early Termination Date, and Tenant hereby authorizes Landlord to date the Promissory Note as of the Early Termination Date, and such Promissory Note shall be returned to Tenant in the event the Early Termination does not occur on or before the day preceding the Maturity Date (as defined in the Promissory Note), and

(b)Tenant shall deliver the remainder of the Lease Modification Payment in cash in the amount of $100,000.00 (the “Cash Payment”) to Landlord within 30 days following Landlord’s delivery to Tenant of the Termination Notice (except to the extent such funds have been drawn from the Security Deposit pursuant to Section 3 below).

For the avoidance of doubt, neither Tenant nor Guarantor shall have the right to terminate the escrow and/or demand the return of the Promissory Note, other than as set forth in Section 2(a) above.

3.Security Deposit. Tenant has not paid Base Rent, TI Rent or Operating Expenses for periods commencing July 1, 2025, and continuing through the date of this Fourth Amendment. In consideration of Landlord’s agreement to enter into this Fourth Amendment, Landlord shall have the right to and shall draw down the entire amount of the Security Deposit and apply the full amount of the Security Deposit, in the amount of $2,781,120.00 evidenced by that certain standby letter of Credit Number: IS00036572OU issued by Wells Fargo Bank, National Association (as amended), towards Tenant’s Base Rent, TI Rent and Operating Expenses due for July 2025, and for Tenant’s Base Rent, TI Rent and Operating Expenses coming due thereafter, until the earlier to occur of (i) the Early Termination Date, or (ii) the date that the Security Deposit has been fully applied to such Base Rent, TI Rent and Operating Expense obligations. If any portion of the Security Deposit is remaining as of the Early Termination Date, Landlord shall first deduct the amount of the Cash Payment therefrom (in which case, Tenant will not need to pay Landlord the Cash Payment to the extent such Cash Payment was paid by the Security Deposit funds) and thereafter return any remaining funds to Tenant. Notwithstanding the foregoing, Landlord shall only be required to return such funds to Tenant if, and only if, Tenant shall have vacated the Premises and delivered possession thereof to Landlord in the condition required by the terms of this Fourth Amendment on or before the Early Termination Date. For the avoidance of doubt, immediately following Landlord’s draw down of the current Security Deposit, there shall be no required Security Deposit under the Lease.

4.Operating Expenses. In the event Landlord exercises its Termination Right and the Early Termination Date occurs on or prior to February 28, 2026, there shall be no reconciliation of operating expenses for calendar year 2025.

5.Abatement of Rent. Notwithstanding anything to the contrary contained in the Lease, once the Security Deposit has been fully exhausted for the payment of Base Rent, TI Rent and Operating Expenses, any Base Rent, TI Rent and Operating Expenses due for periods through February 28, 2026, shall be abated through February 28, 2026. If the Early Termination Date has not occurred prior to March 1, 2026, Tenant shall resume paying full Base Rent, TI Rent and Operating Expenses commencing on March 1, 2026.

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6.Indemnification and Excess Claim Payment. For the avoidance of doubt, notwithstanding any early termination of the Lease, the provisions of Section 16 of the Original Lease shall survive the expiration or earlier termination of the Lease. In particular, Tenant acknowledges and agrees that its defense and indemnification obligations set forth in Section 16 of the Original Lease shall continue to apply to any current and/or future Claims that may arise in connection with DPR Construction, a General Partnership’s or its subcontractors’ provision of labor and services in connection with the construction of improvements or alterations for the benefit of any one or more of Advanced Medicine Partners, LLC (“AMP”), Jaguar Gene Therapy (“Jaguar”), and/or Tenant (collectively, the “Construction Claims”).

If Tenant receives any payment from or on behalf of AMP and/or Jaguar in connection with any current and/or future Claims related to Tenant’s sublease of the Premises to Jaguar pursuant to that certain Sublease dated as of October 26, 2021 (the “Sublease”) or Jaguar’s assignment of such Sublease to AMP, and such amounts are in excess of the actual out-of-pocket costs and expenses incurred by Tenant in relation to the Premises in connection with defaults by AMP and/or Jaguar under the Sublease (a “Sublease-Related Payment”), Tenant shall be bound and obligated to pay Landlord 50% of such Sublease-Related Payment within 10 business days following receipt thereof by Tenant. Notwithstanding the foregoing, any payments specifically related to the Construction Claims shall not be considered a Sublease-Related Payment subject to the terms of this paragraph.

7.Brokers. Landlord represents that they have had no dealings with any real estate broker, finder or other person, with respect to this Fourth Amendment in any manner. Tenant represents that they have engaged a broker in connection with services to lease the Premises and that such broker may assert claims against Tenant in connection with the Early Termination under certain circumstances. Landlord and Tenant agree to indemnify and hold each other harmless from and against any claim or demand of any other broker for any brokerage commission or other fees, and all costs, claims, expenses and liabilities in connection therewith (including, without limitation, attorneys’ fees, disbursements and actual costs) in connection with this Fourth Amendment.

8.OFAC. Tenant and, to Tenant’s knowledge, all beneficial owners of Tenant are currently (a) in compliance with and shall at all times during the Term of the Lease remain in compliance with the regulations of the Office of Foreign Assets Control (“OFAC”) of the U.S. Department of Treasury and any statute, executive order, or regulation relating thereto (collectively, the “OFAC Rules”), (b) not listed on, and shall not during the Term of the Lease be listed on, the Specially Designated Nationals and Blocked Persons List, Foreign Sanctions Evaders List or the Sectoral Sanctions Identifications List, which are all maintained by OFAC and/or on any other similar list maintained by OFAC or other governmental authority pursuant to any authorizing statute, executive order, or regulation, and (c) not a person or entity with whom a U.S. person is prohibited from conducting business under the OFAC Rules.

9.Third Party Releases. Landlord hereby agrees to enter into the Release in the form attached hereto as Exhibit B.

10.Miscellaneous.

(a)This Fourth Amendment is the entire agreement between the parties with respect to the subject matter hereof and supersedes all prior and contemporaneous oral and written agreements and discussions with respect to the subject matter hereof. This Fourth Amendment may be amended only by an agreement in writing, signed by the parties hereto.

(b)This Fourth Amendment is binding upon and shall inure to the benefit of the parties hereto, and this Fourth Amendment may be executed in 2 or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via facsimile, electronic mail (including pdf or any electronic signature process complying with the U.S. federal ESIGN Act of 2000) or other transmission method and any counterpart so delivered shall be deemed to have been duly and

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validly delivered and be valid and effective for all purposes. Electronic signatures shall be deemed original signatures for purposes of this Fourth Amendment and all matters related thereto, with such electronic signatures having the same legal effect as original signatures.

(c)Except as amended and/or modified by this Fourth Amendment, the Lease is hereby ratified and confirmed and all other terms of the Lease shall remain in full force and effect, unaltered and unchanged by this Fourth Amendment. In the event of any conflict between the provisions of this Fourth Amendment and the provisions of the Lease, the provisions of this Fourth Amendment shall prevail. Whether or not specifically amended by this Fourth Amendment, all of the terms and provisions of the Lease are hereby amended to the extent necessary to give effect to the purpose and intent of this Fourth Amendment.

(d)Tenant acknowledges and agrees that the financial terms of this Fourth Amendment are to remain confidential and may not be disclosed by Tenant to anyone, by any manner or means, directly or indirectly, without Landlord’s prior written consent, which may be granted or withheld in Landlord’s sole and absolute discretion. Notwithstanding the foregoing, Tenant may disclose this Fourth Amendment if required by applicable law, regulation or court order, or the financial terms of this Fourth Amendment to Guarantor or any of Tenant’s or Guarantor’s respective attorneys, accountants, employees, advisors or investors who have signed confidentiality agreements or are otherwise bound by confidentiality obligations at least as restrictive as those contained herein. Tenant may share copies of the Release attached hereto as Exhibit B with the beneficiaries of the Release.

[Signatures are on the next page]

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IN WITNESS WHEREOF, the parties hereto have executed this Fourth Amendment as of the day and year first above written.

TENANT:

ADVERUM NC, LLC,
a Delaware limited liability company

By:/s/ Linda Rubinstein

Name: Linda Rubinstein    

Its: CFO    

☒ I hereby certify that the signature, name, and title above are my signature, name and title

LANDLORD:

ARE-NC REGION NO. 21, LLC,
a Delaware limited liability company

By:    Alexandria Real Estate Equities, L.P.,
a Delaware limited partnership,
managing member

By:    ARE-QRS Corp.,
a Maryland corporation,
general partner

By:/s/ Mark Hikin

Name: Mark Hikin    

Its: VP - Real Estate Legal Affairs    

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GUARANTOR CONSENT

The undersigned as Guarantor of the Lease hereby consents to this Fourth Amendment and hereby reaffirms all of the undersigned’s obligations under that certain Guaranty dated as of January 8, 2021 (the “Guaranty”), and affirms that the undersigned shall be liable for all obligations thereunder including, without limitation, those arising in connection with this Fourth Amendment. All references in the Guaranty to the Lease shall refer to the Lease as amended hereby. Guarantor acknowledges that it is obtaining a material benefit from Landlord entering into the Fourth Amendment, and, in consideration of such material benefit, Guarantor has agreed to deliver to Landlord the Promissory Note referenced in the Fourth Amendment.

GUARANTOR:

ADVERUM BIOTECHNOLOGIES, INC.,
a Delaware corporation

By:/s/ Laurent Fischer

Name: Laurent Fischer    

Its: President and CEO Adverum    

☒ I hereby certify that the signature, name,
and title above are my signature, name and title.

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EXHIBIT A

Form of Promissory Note

US$7,400,000.00    Durham, North Carolina

FOR VALUE RECEIVED, and subject to the terms and conditions set forth herein, ADVERUM BIOTECHNOLOGIES, INC., a Delaware corporation (hereinafter referred to as “Maker”), hereby unconditionally promises to pay to ARE-NC REGION NO. 21, LLC, a Delaware limited liability company (and together with its successors and assigns, hereinafter referred to as “Holder”), in the manner hereinafter provided, the principal sum of Seven Million Four Hundred Thousand Dollars and 00/100 ($7,400,000.00), together with interest thereon, all in accordance with the provisions hereinafter specified in this Promissory Note (the “Note”).

1.Accrual of Interest. Interest shall accrue and be computed on the principal amount outstanding from time to time under this Note until the same is repaid in full at a rate equal to five percent (5%) per annum, compounded monthly. Interest shall be calculated hereunder on the basis of a 360-day year for the actual number of days elapsed.

2.Prepayment. Maker shall be permitted to repay this Note, in whole or in part, prior to the Maturity Date without penalty. Any amounts repaid prior to the Maturity Date shall be applied in the manner proscribed in Section 4 of this Note.

3.Maturity Date. The entire unpaid principal amount of this Note, together with all accrued unpaid interest, fees, expenses and other obligations hereunder, shall be due and payable on the earliest to occur of (i) January 31, 2031, or (ii) 30 days from the end of the quarterly reporting period in which Maker (including affiliates of Maker) (A) achieves at least $150,000,000.00 in annual net revenues, including net sales by Maker and affiliates of Maker and/or (B) receives at least $150,000,000.00 in annual royalties paid to Maker and/or affiliates of Maker on the sale of its current lead product candidate, Ixo-vec (the “Lead Product Candidate”) (the “Maturity Date”), or, if earlier, the date on which this Note becomes due and payable pursuant to the terms of this Note. For purposes of determining whether the thresholds in clause (ii) above have been satisfied: (X) if Maker is a reporting company under the Securities Exchange Act of 1934, such determination shall be based on Maker’s annual and quarterly financial statements filed with the SEC; and (Y) if Maker is not a reporting company, such determination shall be based on comparable financial statements prepared in accordance with GAAP (or IFRS, if applicable) and delivered to Holder within the same timeframes as such filings would have been required to be made with the SEC had Maker been a Securities and Exchange Commission reporting company. In addition, Maker shall provide Holder with such related supporting information as may be reasonably requested by Holder to verify compliance with the thresholds, and Holder shall have customary audit and inspection rights, exercisable upon reasonable prior notice, to review Maker’s and its affiliates’ books and records to confirm the accuracy of such financial statements and the satisfaction of the conditions described above.

Notwithstanding the foregoing, if following the date of that certain Fourth Amendment to Lease entered into between Holder and Adverum NC, LLC, a Delaware limited liability company (“Adverum”), Maker or Adverum consummates a Change of Control (as defined below) prior to the Maturity Date, the outstanding principal balance of this Note, together with accrued interest, shall be prepaid in full in Maker’s sole and exclusive discretion (a) in cash within three (3) business days following the later of (i) closing date of the Change of Control, and (ii) the date of this Note, (b) by issuance of shares of Maker’s common stock on the later of (i) such closing, and (ii) three (3) business days following the date of this Note, provided, Maker shall have a then-current market capitalization of $150,000,000, such equity must be freely transferable and publicly traded and not “restricted securities” in the hands of Holder within the meaning of Rule 144 under the Securities Act (as defined below), and Maker shall, if necessary, file and maintain an effective registration statement covering the resale of such shares to ensure such status, and no more than 4.5% the equity of Maker shall be transferred, or (c) by a combination of (a) and (b) above.

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Such repayment of the Note shall be a condition precedent to the consummation of any Change of Control, and Maker shall cause such requirement to be expressly included in the definitive transaction documents for such Change of Control. “Change of Control” shall mean (A) any consolidation or merger of Maker or Adverum with or into any other corporation, limited liability company, partnership, trust, joint stock company, business trust, unincorporated association, joint venture, governmental authority or other legal entity of any nature whatsoever, or any other corporate reorganization, other than any such consolidation, merger or reorganization in which the equity holders of Maker or Adverum, as applicable, immediately prior to such consolidation, merger or reorganization, continue to hold at least a majority of the voting power of the surviving entity (or, if the surviving entity is a wholly owned subsidiary, its parent), (B) any transaction or series of related transactions to which Maker or Adverum is a party in which in excess of 40% of the voting power of Maker or Adverum, as applicable, is transferred, (C) a sale, lease, exclusive license or other disposition of all or substantially all of the assets of Maker, or Adverum, as applicable, (D) the common shares of Maker are delisted from the principial U.S. securities exchange on which it is then listed and not relisted at that time on another national securities exchange; or (E) the sale, exclusive license or other disposition of the Lead Product Candidate or other transfer of all or substantially all of the rights thereto; provided, however, that in each case of (C) and (E) above, an exclusive license granted in the ordinary course of business for bona fide development or commercialization purposes shall not constitute a Change of Control unless such license (i) relates to all or substantially all of Maker’s rights in the Lead Product Candidate on a worldwide basis, and (ii) has aggregate upfront payments in excess of $150 million. Notwithstanding the foregoing, the following will not constitute a Change of Control: (i) a sale of capital stock to underwriters in an underwritten public offering of a Maker’s capital stock solely for the purpose of financing, or (ii) the acquisition of securities of Maker by any third party or group of third parties that acquires such securities in a transaction or series of related transactions, the primary purpose of which is to obtain financing for Maker through the issuance of equity securities (provided that no such financing is structured, in whole or in part, for the purpose of effecting a Change of Control).

4.Manner and Application of Payments. All amounts payable hereunder shall be payable to Holder at Maker’s sole and exclusive discretion (i) by wire transfer of immediately available funds and in lawful money of the United States of America without set-off, deduction or counterclaim at such place as Holder may from time to time designate in writing to Maker, (ii) subject to Maker’s right in connection with a Change in Control, by issuance of Maker’s equity valued at the lesser of (X) the closing price per share of such common stock on the principal U.S. securities exchange on which it is then listed on the trading day immediately prior to the date of payment and (Y) the volume-weighted average price (VWAP) of such common stock for the ten (10) consecutive trading days ending on the trading day immediately prior to the date of payment, in each case as reported by Bloomberg (or, if not available, another nationally recognized reporting service), or (iii) any combination of (i) and (ii) above. If any payment of principal or interest under this Note shall be payable on a day other than a business day such payment shall be made on the next succeeding business day and interest shall be payable at the rate specified in this Note during such extension.

5.Representation and Warranties.

(a)Maker hereby represents and warrants to Holder that:

(i)Maker is validly existing as a corporation under the laws of the State of Delaware and has the power and authority to execute and deliver this Note and has duly executed and delivered this Note;

(ii)this Note is the legal, valid and binding obligation of Maker, enforceable in accordance with its terms; and

(iii)the execution, delivery and performance of this Note and the transaction evidenced hereby does not (a) require the consent or approval of any other party (including any governmental or regulatory party) other than any consent or approval that has already been obtained, (b) violate any law, regulation, agreement, order, writ, judgment, injunction, decree, determination or award presently in effect to which Maker is a party or to which Maker or any of its assets may be subject, or (c) conflict with or

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constitute a breach of, or default under, or require any consent under, or result in the creation of any lien, charge or encumbrance upon the property or assets of Maker pursuant to any other agreement or instrument to which Maker is a party or is bound or by which its properties may be bound or affected.

(b)Holder hereby represents and warrants to Maker that:

(i)Holder is an “accredited investor” as defined under the Securities Act of 1933, as amended (“Securities Act”); and

(ii)Holder understands that the Note has not been registered under the Securities Act or any applicable state securities law and is acquiring the Note for its own account and not with a view to or for distributing or reselling the Note.

6.Covenants.

(a)Further Assurances. Maker shall execute, acknowledge and deliver, or cause to be executed, acknowledged or delivered, any and all such further assurances and other agreements or instruments, and take or cause to be taken all such other action, as shall be necessary from time to time or that Holder may reasonably request, to give full effect to the Note and the obligations hereunder.

(b)Maintenance of Existence. Maker shall preserve, renew and maintain in full force and effect its corporate or organizational existence and take all reasonable action to maintain all rights and privileges necessary in the ordinary course of business.

7.Events of Default. Each of the following acts, events or circumstances shall constitute an Event of Default (each an “Event of Default”) hereunder:

(a)Maker shall default in the payment when due (in accordance with the terms of this Note);

(b)(i) Maker shall commence a voluntary case concerning itself under any bankruptcy, insolvency or similar laws or statutes (including Title 11 of the United States Code, as amended, supplemented or replaced) (collectively, the “Bankruptcy Code”); or (ii) an involuntary case is commenced against Maker and is not dismissed within sixty (60) days; or (iii) a custodian (as defined in the Bankruptcy Code) is appointed for, or takes charge of, all or substantially all of the property of Maker or Maker commences any other proceeding under any reorganization, arrangement, adjustment of debt, relief of debtors, dissolution, insolvency or liquidation or similar law of any jurisdiction whether now or hereafter in effect relating to Maker or there is commenced against Maker any such proceeding; or (iv) any order of relief or other order approving any such case or proceeding is entered; or (v) Maker is adjudicated insolvent or bankrupt; or (vi) Maker makes a general assignment for the benefit of creditors; or (vii) Maker shall call a meeting of its creditors with a view to arranging a composition or adjustment of its debts; or (viii) Maker shall by any act or failure to act consent to, approve of or acquiesce in any of the foregoing;

(c)Maker shall dissolve or for any reason cease to be in existence;

(d)any representation or warranty made or that is deemed made by Maker pursuant to this Note shall have been false or misleading in any material respect on the date as of which such representation or warranty was made or deemed made; or

(e)any material adverse effect shall occur or could reasonably be expected to occur with respect to (a) the validity or enforceability of this Note or the rights, powers and privileges purported to be created hereby, or (b) the right and remedies of the Holder hereunder.

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If an Event of Default, other than an Event of Default described in Section 7(b), occurs, Holder by written notice to Maker may declare the principal of and accrued interest on this Note to be immediately due and payable. Upon a declaration of acceleration, such principal and interest shall become immediately due and payable. If an Event of Default described in Section 7(b) occurs, the principal of on this Note then outstanding shall become immediately due and payable without any declaration or other act on the part of Holder.

As used herein, the term “Default” means any event or condition which constitutes an Event of Default or which upon notice, lapse of time or both would, unless cured or waived, become an Event of Default.

8.Remedies; Cumulative Rights. In addition to the rights provided under Section 7, and without limitation with respect to other applicable law, Maker acknowledges that this Note is a “business contract” as that term is used under N.C.G.S. § 6-21.6 (or any successor thereto). Holder shall also have any other rights that Holder may have been afforded under any contract or agreement at any time, and any other rights that Holder may have pursuant to applicable law. No delay on the part of Holder in the exercise of any power or right under this Note or under any other instrument executed pursuant hereto shall operate as a waiver thereof, nor shall a single or partial exercise of any power or right preclude other or further exercise thereof or the exercise of any other power or right. No extension of time of the payment of this Note or any other modification, amendment or forbearance made by agreement with any person now or hereafter liable for the payment of this Note shall operate to release, discharge, modify, change or affect the liability of any co-borrower, endorser, guarantor or any other person with regard to this Note, either in part or in whole. No failure on the part of Holder or any holder hereof to exercise any right or remedy hereunder, whether before or after the occurrence of a default, shall constitute a waiver thereof, and no waiver of any past default shall constitute a waiver of any future default or of any other default. No failure to accelerate the debt evidenced hereby by reason of an Event of Default hereunder or acceptance of a past due installment, or indulgence granted from time to time shall be construed to be a waiver of the right to insist upon prompt payment thereafter, or to impose late payment charges, or shall be deemed to be a novation of this Note or any reinstatement of the debt evidenced hereby, or a waiver of such right of acceleration or any other right, or be construed so as to preclude the exercise of any right which Holder or any holder hereof may have, whether by the laws of the State of North Carolina, by agreement or otherwise, and none of the foregoing shall operate to release, change or affect the liability of Maker under this Note, and Maker hereby expressly waives (to the extent allowed by law) the benefit of any statute or rule of law or equity which would produce a result contrary to or in conflict with the foregoing.

9.Waivers. Except for the notices expressly required by the terms of this Note (which rights to notice are not waived by Maker), Maker, for itself and its successors and assigns, hereby forever waives presentment, protest and demand, notice of protest, demand, dishonor and non-payment of this Note, and all other notices in connection with the delivery, acceptance, performance, default or enforcement of the payment of this Note, and waives and renounces (to the extent allowed by law), all rights to the benefits of any statute of limitations and any moratorium, appraisement, and exemption now allowed or which may hereby be provided by any federal or state statute or decisions against the enforcement and collection of the obligations evidenced by this Note and any and all amendments, substitutions, extensions, renewals, increases, and modifications hereof. Nor shall Maker, or anyone claiming by or under Maker, claim or seek to take advantage of N.C.G.S. § 26-7, et seq. Maker expressly agrees that this Note may be extended or subordinated, by forbearance or otherwise, from time to time, without in any way affecting the liability of Maker. No consent or waiver by Holder with respect to any action or failure to act which without such consent or waiver would constitute a breach of any provision of this Note shall be valid or binding unless in writing signed by Holder and then only to the extent expressly specified therein. Neither the failure nor any delay in exercising any right, power or privilege under this Note, at law or equity, or otherwise available agreement, will operate as a waiver of such right, power or privilege and no single or partial exercise of any such right, power or privilege by Holder will preclude any other or further exercise of such right, power or privilege.

10.Notices. All notices required to be given hereunder shall be in writing and shall be deemed to be duly given if personally delivered or emailed and confirmed, or mailed by certified mail, return receipt requested, or nationally recognized overnight delivery service with proof of receipt

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maintained, at the following address (or any other address that any such party may designate by written notice to the other parties):

If to Maker:    Adverum Biotechnologies, Inc.

100 Cardinal Way

Redwood City, CA 94063

Attention: General Counsel

If to Holder:    ARE-NC Region No. 21, LLC

26 North Euclid Avenue

Pasadena, CA 91101

Attention: Corporate Secretary

Re: 14 TW Alexander

11.Usury. All terms, conditions and agreements herein are expressly limited so that in no contingency or event whatsoever, whether by acceleration of maturity of the unpaid principal balance hereof, or otherwise, shall the amount paid or agreed to be paid to Holder for the use, forbearance or detention of the money advanced hereunder exceed the highest lawful rate permissible under applicable laws. If, from any circumstances whatsoever, fulfillment of any provision hereof shall involve transcending the limit of validity prescribed by law which a court of competent jurisdiction, in a final determination may deem applicable hereto, then ipso facto, the obligation to be fulfilled shall be reduced to the limit of such validity, and if under any circumstances Holder shall ever receive as interest an amount which would exceed the highest lawful rate, such amount which would be excessive interest shall be applied to reduction of the unpaid principal balance due hereunder and not to the payment of interest.

12.Severability; Invalidity. Maker and Holder intend and believe that each provision in this Note comports with all applicable local, state and federal laws and judicial decisions. However, if any provisions, provision, or portion of any provision in this Note is found by a court of competent jurisdiction to be in violation of any applicable local, state or federal ordinance, statute, law, or administrative or judicial decision, or public policy, including applicable usury laws, and if such court would declare such portion, provision or provisions of this Note to be illegal, invalid, unlawful, void or unenforceable as written, then it is the intent of all parties hereto that such portion, provision or provisions shall be given force and effect to the fullest possible extent they are legal, valid and enforceable, and the remainder of this Note shall be construed as if such illegal, invalid, unlawful, void or unenforceable portion, provision or provisions were severable and not contained herein, and the rights, obligations and interest of Maker and Holder under the remainder of this Note shall continue in full force and effect.

13.No Strict Construction. The language used in this Note 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.

14.Assignment. Maker may not transfer, assign or delegate any of its rights or obligations hereunder without the prior written consent of Holder. Holder shall have the right, without the consent of Maker, to transfer or assign, in whole or in part, its rights and interests in and to this Note to any of its affiliates, and, as used herein, the term “Holder” shall mean and include such successors and assigns. This Note shall accrue to the benefit of Holder and its permitted successors and assigns and shall be binding upon the undersigned and its successors and assigns.

15.Amendment. The provisions of this Note may be amended only by a written instrument signed by Maker and Holder.

16.Governing Law. THIS NOTE AND THE RIGHTS AND OBLIGATIONS OF ALL PARTIES HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED UNDER THE LAWS OF THE STATE OF NORTH CAROLINA WITHOUT REGARD TO ITS CONFLICT OF LAWS PRINCIPLES.

17.Jurisdiction; Waiver of Jury Trial. ALL ACTIONS OR PROCEEDINGS ARISING IN CONNECTION WITH THIS NOTE SHALL BE FILED, TRIED AND LITIGATED IN THE STATE AND

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FEDERAL COURTS LOCATED IN CHARLOTTE, NORTH CAROLINA. MAKER WAIVES ITS RIGHT TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS NOTE, INCLUDING CONTRACT CLAIMS, BREACH OF DUTY CLAIMS, AND ALL OTHER COMMON LAW OR STATUTORY CLAIMS. MAKER HAS REVIEWED THIS WAIVER AND KNOWINGLY AND VOLUNTARILY WAIVES THE AFORESAID TRIAL RIGHTS FOLLOWING CONSULTATION WITH LEGAL COUNSEL. IN THE EVENT OF LITIGATION, A COPY OF THIS NOTE MAY BE FILED AS A WRITTEN CONSENT TO A TRIAL BY THE COURT.

18.Prevailing Party’s Fees. In the event that Holder should bring suit or commence any suit or proceeding arising out of or related to the non-payment of this Note against Maker, then all reasonable costs and expenses, including reasonable attorneys’ fees and expert fees, incurred by Holder in connection with such suit or proceeding shall be paid by Maker if Maker is the non-prevailing party, which obligation on the part of Maker shall be deemed to have accrued on the date of the commencement of such action and shall be enforceable if the action is prosecuted to judgment.

[Continued on following page]

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IN WITNESS WHEREOF, the undersigned has executed this Note as of the date first written above.

ADVERUM BIOTECHNOLOGIES, INC.,

a Delaware corporation

By:

Name:

Its:

☐ I hereby certify that the signature, name, and title above are my signature, name and title.

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EXHIBIT B

RELEASE

1.For good and valuable consideration the receipt of which is hereby acknowledged, except as set for in Section 2 below, ARE-NC Region No. 21, LLC (“ARE”) fully waives, releases, acquits, and forever discharges (collectively, the “Release”) Jaguar Gene Therapy, LLC (“Jaguar”) and Advanced Medicine Partners, LLC (“AMP”) and each of their current and former affiliates, officers, members, principals, stakeholders, directors, owners, agents, employees or anyone acting on their behalf, in both their official and individual capacities, and all of their heirs, legatees, representatives, consultants, insurers, sureties, parents, subsidiaries, related entities, affiliates, attorneys, successors, and assigns thereof (collectively, the “Jaguar and AMP Released Parties”) from all claims, actions, causes of action, demands, rights, liens, damages, costs, sums of money, accounts, covenants, contracts, promises, attorneys’ fees, and all liabilities of any kind or nature whatsoever at law, in equity, or otherwise (collectively, “Claims”), which ARE ever had, now has, or may have, whether now known or unknown or not now in existence, against the Jaguar and AMP Released Parties as a result of or related to (1) that certain Lease Agreement entered into between Adverum NC, LLC (“Adverum”) and ARE for the premises located at 14 TW Alexander Drive, Durham, North Carolina (the “Premises”) dated January 8, 2021, as amended by that certain First Amendment to Lease Agreement dated April 15, 2021, and that certain Acknowledgment of Commencement Date dated April 23, 2021, that certain Consent to Sublease and Second Amendment to Lease dated October 26, 2021, that certain Third Amendment to Lease Agreement and First Amendment to Consent to Sublease dated as of April 3, 2023, and that certain letter agreement dated June 6, 2025 (all together, as amended, the “Lease”), (2) the Premises, (3) that certain Sublease dated October 26, 2021 (the “Sublease”) and that certain Side Letter to Sublease dated October 26, 2021 between Adverum and Jaguar, or (4) that certain Assignment and Assumption Agreement dated April 21, 2023 (the “Assignment”) between Jaguar and AMP.

2.The Release shall only apply so long as Jaguar, AMP and/or the Jaguar and AMP Released Parties do not bring any Claims against ARE or any of its current and former affiliates, officers, members, principals, stakeholders, directors, owners, agents, employees or anyone acting on their behalf, in both their official and individual capacities, and all of their heirs, legatees, representatives, consultants, insurers, sureties, parents, subsidiaries, related entities, affiliates, attorneys, successors, and assigns. Notwithstanding anything to the contrary contained in Section 1 above, the Release shall not apply to (i) Claims for injury or death to persons occurring within or about the Premises or the Project arising directly or indirectly out of the access to, use or occupancy of the Premises or the Project by Jaguar, AMP and/or the Jaguar and AMP Released Parties, and (ii) to Claims related to environmental contamination of the Premises that was caused by, contributed to or exacerbated by Jaguar, AMP and/or the Jaguar and AMP Released Parties.

3.ARE hereby represents and warrants that it is the current owner and landlord of the Premises and that ARE has not assigned any claims being released by the above Section 1.

[Signature page follows]

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IN WITNESS WHEREOF, the undersigned has executed this Release as of September 30, 2025.

ARE-NC REGION NO. 21, LLC,

a Delaware limited liability company

By:    Alexandria Real Estate Equities, L.P.,
a Delaware limited partnership,
managing member

By:    ARE-QRS Corp.,
a Maryland corporation,
general partner

By: /s/Mark Hikin    

Name: Mark Hikin    

Its: Vice President    

Real Estate Legal Affairs

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