On behalf of the board of directors (the “Board of Directors” or the “Board”) of Adverum Biotechnologies, Inc. (“Adverum,” “we,” “us” or “our”), we cordially invite you to attend the 20232024 Annual Meeting of Stockholders (the “2023“2024 Annual Meeting”), which will be held on June 9, 202317, 2024 at 8:00 a.m., Pacific Daylight Time via a live audio webcast at www.virtualshareholdermeeting.com/ADVM2023.ADVM2024.

The proxy statement and notice of annual meeting accompanying this letter provide you with more specific information concerning the proposals to be voted on at the 20232024 Annual Meeting. You will also be asked to transact such other business, if any, as may properly come before the 20232024 Annual Meeting or any adjournment or postponement thereof.

The record date for the 20232024 Annual Meeting is April 12, 202322, 2024 (the “Record Date”). Only stockholders of record at the close of business on that date may vote at the meeting or any adjournment thereof. A complete list of such stockholders will be available for examination by any stockholder for any purpose germane to the 20232024 Annual Meeting beginning ten days prior to the meeting at our principal executive offices located at 100 Cardinal Way, Redwood City, California 94063. If you would like to view the list, please contact our Corporate Secretary to schedule an appointment by calling (650) 656-9323 or writing to him at the address above. In addition, the list will be available for inspection by stockholders on the virtual meeting website during the meeting by clicking on the ‘Stockholder List’ link located under the ‘Meeting Links’ section of the virtual meeting website once logged in.

Under Securities and Exchange Commission rules, we are providing access to the proxy materials for the 20232024 Annual Meeting to stockholders via the internet. Accordingly, you can access the proxy materials and vote at www.proxyvote.com. Instructions for accessing the proxy materials and voting are described below and in the notice of annual meeting that we will mail to our stockholders on or about April 25, 2023.May 2, 2024. Your vote is very important. Whether or not you plan to attend the meeting, please carefully review the enclosed proxy statement and then cast your vote, regardless of the number of shares you hold. If you are a stockholder of record, you may vote over the internet, by telephone, or, if you request to receive a printed set of the proxy materials, by completing, signing, dating and mailing the accompanying proxy card in the return envelope. Submitting your vote via the internet or by telephone or proxy card will not affect your right to vote online if you decide to attend the 20232024 Annual Meeting, which will be held virtually via the Internet. If your shares are held in street name (held for your account by a broker or other nominee), you will receive instructions from your broker or

This proxy statement and our Annual Report to Stockholders, which includes our Annual Report on Form 10-K for the year ended December 31, 2022,2023, are available at http://investors.adverum.com andwww.proxyvote.com.

We intend to mail the proxy materials for the 20232024 Annual Meeting on or about April 25, 2023.May 2, 2024.

The following questions and answers are intended to briefly address some commonly asked questions regarding the 20232024 Annual Meeting. These questions and answers may not address all questions that may be important to you as a stockholder. You should read the more detailed information contained elsewhere in this proxy statement and the documents referred to in this proxy statement.

Our Board is made up of directors with extensive experience leading and advising biotechnology and pharmaceutical companies. Our Board strives to ensure that our directors have backgrounds that collectively add significant value to our strategic decisions and enable them to provide oversight of management to ensure accountability to our stockholders. In addition, we have worked hard to strike the right balance between long-term understanding of our business and fresh external perspectives, as well as to ensure diversity within the boardroom.

We believe that a diversity of viewpoints, background, experience and other characteristics, such as gender, race, ethnicity, culture, nationality and sexual orientation, are an important part of the composition of our Board. To this end, in 2018 our Board adopted the so-called “Rooney Rule,” by amending our Corporate Governance Guidelines to provide that when evaluating candidates for nomination and new directors, the Board shall:

Our Board’s Nominating and Corporate Governance Committee is responsible for making recommendations to our Board regarding candidates for directorships and composition and organization of our Board. Through their work, we have assembled a Board composed of members with diverse backgrounds, skills and experience, and we believe this diversity contributes to an effective and well-balanced Board that is able to provide valuable insight into, and effective oversight of, our senior management team.

Below is a breakdown of the composition of our nominees for director and directors continuing following the 20232024 Annual Meeting by board independence, non-employee status, and tenure of service (as of April 15, 2023)22, 2024), as well as the skills and experience possessed by our nominees for director and directors continuing following the 20232024 Annual Meeting across selected categories that we believe are valuable to the oversight of our business.

Our Board is divided into three classes. Each class has a three-year term. Except as otherwise provided by law, vacancies on our Board may be filled only by individuals elected by a majority of the remaining directors. A director elected by our Board to fill a vacancy in a particular class, including a vacancy created by an increase in the number of directors, shall serve for the remainder of the full term of that class and until such director’s successor is elected and has qualified, or until such director’s earlier death, resignation or removal.

The three nominees for Class IIII directors are Drs. Lupher, OzdenSoo Hong, Dawn Svoronos and Whitcup,Reed Tuckson, M.D., each of whom has agreed to stand for election as Class IIII directors. Each nominee was selected by the Board upon the unanimous recommendation of the Nominating and Corporate Governance Committee. Dr. LupherMs. Svornos and Dr. WhitcupTuckson were previously elected to our Board by our stockholders. Dr. Ozdenstockholders in 2021. Ms. Hong was recommended for nomination to our Board by a third-party search firm and was initially appointed by our Board in March 2022. The specific experience, qualifications, attributes and skills of each nominee that led the Board to conclude that the individual should serve as a director are described in each nominee’s biography below. If elected, each nominee will serve for a three-year term expiring at the 20262027 annual meeting of stockholders, or until his or her successor is elected and has qualified, or until his or her earlier death, resignation or removal.

Pursuant to our Bylaws, written notice by stockholders of qualifying nominations for election to our Board of Directors must have been received by our Corporate Secretary by March 12, 2023.11, 2024. We did not receive any such notices, and no other nominations for election to our Board may be made by stockholders at the 20232024 Annual Meeting.

Our nominees for director and directors continuing following the 20232024 Annual Meeting and their ages as of April 15, 202322, 2024 are:

The following is a brief biography and discussion of the specific attributes, qualifications, experience and skills of each nominee for director and each director whose term will continue after the 20232024 Annual Meeting. Our Board and management encourage each nominee for director and each continuing director to attend our annual meetings of stockholders.

The Audit Committee of our Board has selected Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2023,2024, and is seeking ratification of such selection by our stockholders at the 20232024 Annual Meeting. Ernst & Young LLP has served as our independent registered public accounting firm since 2018. Representatives of Ernst & Young LLP are expected to be present at the 20232024 Annual Meeting. They will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions.

Neither our bylaws nor other governing documents or law require stockholder ratification of the selection of Ernst &Young LLP as our independent registered public accounting firm. However, the Audit Committee is submitting the selection of Ernst & Young LLP to our stockholders for ratification as a matter of good corporate practice. If our stockholders fail to ratify the selection, the Audit Committee will reconsider whether or not to retain Ernst & Young LLP. Even if the selection is ratified, the Audit Committee in its discretion may select a different independent registered public accounting firm at any time during the year if they determine that such a change would be in the best interests of Adverum and our stockholders.

For the years ended December 31, 20222023 and 2021,2022, Ernst & Young LLP billed the approximate fees set forth below. All fees described in the table below were preapproved by the Audit Committee.

The Audit Committee is responsible for reviewing the terms of the proposed engagement of the independent registered public accounting firm for audit or permissible non-audit services and for preapproving all such engagements. The Audit Committee has adopted a policy for the preapproval of all audit and non-audit services to be performed for us by the independent registered public accounting firm. In providing any preapproval, the Audit Committee considers whether the services to be approved are consistent with the SEC’s rules on auditor independence. The Audit Committee has considered the role of Ernst & Young LLP in providing audit and audit-related services to us and has concluded that such services are compatible with Ernst & Young LLP’s role as our independent registered public accounting firm.

The affirmative vote of a majority of the shares cast in person or by proxy at the 20232024 Annual Meeting (excluding abstentions and broker non-votes, if any) will be required to ratify the selection of Ernst & Young LLP. Abstentions will have no effect on this proposal.

The primary purpose of the Audit Committee is to oversee our financial reporting processes on behalf of our Board. The Audit Committee’s functions are more fully described in its charter, which is available on our website at http://investors.adverum.com.

In fulfilling its oversight responsibilities, the Audit Committee reviewed and discussed with management Adverum’s audited financial statements for the year ended December 31, 2022.2023. The Audit Committee has discussed with Ernst & Young LLP (“E&Y”), Adverum’s independent registered public accounting firm for 2022,2023, the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board (“PCAOB”) and the Securities and Exchange Commission. In addition, the Audit Committee received from E&Y the written disclosures and the letter required by the applicable requirements of the PCAOB regarding E&Y’s communications with the Audit Committee concerning independence, and has discussed with E&Y its independence. Finally, the Audit Committee discussed with E&Y, with and without management present, the scope and results of E&Y’s audit of our financial statements for the year ended December 31, 2022.2023.

Based on these reviews and discussions, the Audit Committee recommended to our Board that our audited financial statements be included in our Annual Report on Form 10-K for the year ended December 31, 20222023 filed with the SEC.

Under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) and Section 14A of the Exchange Act, our stockholders are entitled to vote to approve, on an advisory basis, the compensation of our named executive officers as disclosed in this proxy statement in accordance with SEC rules.

Accordingly, the Board is asking you to indicate your support for the compensation of our named executive officers as described in this proxy statement by casting a non-binding advisory vote “FOR” the following resolution:

“RESOLVED, that the compensation paid to Adverum’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the compensation discussion and analysis, compensation tables and narrative discussion, is hereby APPROVED.”

Because the vote is advisory, it is not binding on our Board, our Compensation Committee or us. Nevertheless, the views expressed by the stockholders, whether through this vote or otherwise, are important to management and the Board and, accordingly, the Board and the Compensation Committee intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements.

Advisory approval of this proposal requires “FOR” votes from the holders of a majority of the shares cast in person or by proxy (excluding abstentions and broker non-votes, if any). Abstentions and broker non-votes will have no effect on this proposal.

OurAs most recently approved by stockholders have recommended,at the annual meeting of stockholders in 2020, and consistent with our Board has approved,Board’s recommendation, we are submitting this proposal for a frequency of each year for advisory votes on executive compensation. Accordingly, the next advisorynon-binding vote on executive compensation will be at our 2024 Annual Meeting of Stockholders.an annual basis.

On April 29, 2024, our Board approved the Adverum Biotechnologies, Inc. 2024 Equity Incentive Award Plan (the “2024 Plan”), subject to stockholder approval. Currently, we maintain the Adverum Biotechnologies, Inc. 2014 Equity Incentive Award Plan (the “2014 Plan”) to grant stock options, restricted stock unit awards and other stock awards to our employees, consultants and directors. Our Board adopted the 2014 Plan in July 2014 and it was amended most recently in December 2019. Approval of the Delaware General Corporation Law (“DGCL”) was amended effective August 1, 20222024 Plan by our stockholders will allow us to authorize exculpationgrant stock options, restricted stock unit awards and other awards at levels determined appropriate by our Board and Compensation Committee. The 2024 Plan allows us to attract, retain and motivate selected employees, consultants and directors through the granting of officersstock-based compensation awards and cash-based performance bonus awards. Our Board believes that the 2024 Plan is an integral part of Delaware corporations (Section 102(b)(7) Amendment). Specifically,our long-term compensation philosophy and that the amendment extends2024 Plan is necessary to continue providing the opportunityappropriate levels and types of equity compensation. If the 2024 Plan is approved by our stockholders, no further awards will be granted under the 2014 Plan following such approval. However, any awards outstanding under the 2014 Plan will continue to be governed by their existing terms.

Subject to adjustment for Delaware corporationscertain changes in our capitalization, if this Proposal 4 is approved by our stockholders, the aggregate number of shares of common stock that may be issued under the 2024 Plan will be equal to exculpate their officers, in addition to their directors, for personal liability for breachthe sum of (i) 2,160,600 shares of common stock and (ii) any of the dutyshares of care in certain actions. This provision would not exculpate officers from liability for breachcommon stock which as of the dutyeffective date of loyalty, actsthe 2024 Plan are available for issuance under the 2014 Plan, or omissionsare subject to awards under the 2014 Plan that, on or after the effective date of the 2024 plan, terminate, expire or lapse for any reason without the delivery of shares of common stock to the holder thereof, up to a maximum of 2,488,380 shares of common stock.

To the extent that an award terminates, expires or lapses for any reason or an award is settled in cash without the delivery of shares, any shares subject to the award at such time will be available for future grants under the 2024 Plan. However, the following shares shall not be available for future grants of awards under the 2024 Plan: (a) shares tendered to or withheld to satisfy the grant, exercise price or tax withholding obligation with respect to an award under the 2024 Plan; (b) shares subject to a stock appreciation right that are not issued in good faith orconnection with the stock settlement of the stock appreciation right on exercise thereof; and (c) shares repurchased on the open market with the cash proceeds from the exercise of options.

To the extent that involve intentional misconduct orshares of our common stock are repurchased by us prior to vesting at the same price paid by the holder (or a knowing violationlower price) so that shares are returned to us, such shares will be available for future grants under the 2024 Plan. The payment of dividend equivalents in cash in conjunction with any outstanding awards will not be counted against the shares available for issuance under the 2024 Plan. To the extent permitted by applicable law or any transactionexchange rule, shares issued in which the officer derived an improper personal benefit, nor would this provision exculpate such officers from liability for claims brought byassumption of, or in substitution for, any outstanding awards of any entity acquired in any form of combination by us or any of our subsidiaries will not be counted against the rightshares available for issuance under the 2024 Plan.

TheOur Board believes itthat our future success depends, in large part, on our ability to maintain a competitive position in retaining and motivating our employees, consultants and directors and that the issuance of equity awards is necessarya key element in accomplishing these goals. The 2024 Plan will allow us to continue to provide protectionperformance-based incentives to officers to the fullest extent permitted by law in order to attract and retain top talent. This protection has long been afforded to directors. Accordingly,our eligible service providers. Therefore, the Board believes that the proposal to extend exculpation to officers2024 Plan is fair and in the best interests of the corporationCompany and its stockholders. Accordingly, the Board has deemed it advisable that the Adverum Amendedstockholders and Restated Certificaterecommends a vote in favor of Incorporation be amended to add a new Article X, to read in its entirety as follows:this Proposal 4.

No officerAs of the Corporation shall have any personal liability to the Corporation or its stockholdersApril 22, 2024, we had 20,002 shares available for monetary damages for any breach of fiduciary duty as an officer, except to the extent such exemption from liability or limitation thereof is not permittedgrant under the General Corporation Law of the State of Delaware as the same exists or hereafter may be amended. Any amendment, repeal or modification of this Article X, or the adoption of any provision of the Restated Certificate inconsistent with this Article X, shall not adversely affect any right or protection of an officer of the Corporation with respect to any act or omission occurring prior to such amendment, repeal, modification or adoption.2014 Plan. If the General Corporation Law2024 Plan and the new share reserve of the State of Delaware2,160,600 shares is amendedapproved by our stockholders, we will have 2,180,602 shares available for grant immediately after approval by the stockholders of this Article X to authorize corporate action further eliminating or limiting the personal liability of officers, then the liability of an officer of the Corporation shall be eliminated or limited to the fullest extent permitted by the General Corporation Law of the State of Delaware as so amended.

The Boardfollowing table provides certain additional information regarding all of our equity incentive plans.

Generally, the recipient of a stock unit structured to conform to the requirements of Section 409A of the Code or an exception to Section 409A of the Code will recognize ordinary income at the time the stock is delivered equal to the excess, if any, of the fair market value of the shares received over any amount paid by the recipient in exchange for the shares.

We will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of commonthe stock outstandingaward.

Where the stock appreciation rights are granted with a strike price equal to the fair market value of the underlying stock on the recordgrant date, for the 2023 Annual Meetingrecipient will recognize ordinary income equal to the fair market value of the stock or cash received upon such exercise. We will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock appreciation right.

Any of the awards above may be granted with performance vesting conditions, and the tax treatment will be requiredas set forth above, but with the fulfillment of the performance conditions being the vesting event.

The tax treatment for deferred stock awards and deferred stock unit awards will be as set forth above for restricted stock awards and restricted stock unit awards, except that the taxable event will occur upon the satisfaction the deferral condition (other than with respect to approveemployment taxes, which may be due in the Reverse Split Proposal.year of vesting).

We have adopted a code of business conduct and ethics that applies to all of our employees, officers and directors, including those officers responsible for financial reporting. The code of business conduct and ethics is available on our website at http://investors.adverum.com. We intend to satisfy the disclosure requirements under Item 5.05 of the SEC Form 8-K regarding an amendment to, or waiver from, a provision of our Code of Business Conduct and Ethics by posting such information on our website at the website address and location specified above. The reference to our website does not constitute incorporation by reference of the information contained at or available through our website.

We believe in sound corporate governance practices and have adopted formal Corporate Governance Guidelines to enhance our effectiveness. Our Board adopted these Corporate Governance Guidelines to ensure that it has the necessary practices in place to review and evaluate our business operations as needed and to make decisions that are independent of our management. The Corporate Governance Guidelines are also intended to align the interests of our directors and management with those of our stockholders. The Corporate Governance Guidelines set forth the practices our Board follows with respect to Board and committee composition and selection, board meetings, Chief Executive Officer performance evaluation and management development and succession planning for senior management, including the Chief Executive Officer position. A copy of our Corporate Governance Guidelines is available on our website at http://investors.adverum.com.

Our common stock is listed on The Nasdaq GlobalCapital Market. Rule 5605 of the MarketplaceNasdaq Listing Rules of the Nasdaq Stock Market LLC (the “Nasdaq Listing Rules”) requires that independent directors compose a majority of a listed company’s board of directors within one year of listing. In addition, the Nasdaq Listing Rules require that, subject to specified exceptions, each member of a listed company’s audit and compensation committees be independent and that audit committee members also satisfy independence criteria set forth in Rule 10A-3 under the Exchange Act. Under Nasdaq Listing Rule 5605(a)(2), a director will only qualify as an “independent director” if, in the opinion of the board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. Nasdaq Listing Rule 5605(a)(2) also specifies certain categories of persons who will not be considered independent, including employees, family members of executive officers and recipients of compensation from the company in excess of $120,000 during any period of twelve consecutive months within the past three years, subject to certain exceptions. To be considered independent for purposes of Rule 10A-3 under the Exchange Act, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee: (1) accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries; or (2) be an affiliated person of the listed company or any of its subsidiaries. In addition to satisfying general independence requirements under the Nasdaq Listing Rules, members of the compensation committee must also satisfy additional independence requirements set forth in Nasdaq Listing Rule 5605(d)(2). To be considered independent for purposes of Nasdaq Listing Rule 5605(d)(2), our Board must consider all factors specifically relevant to determining whether a director has a relationship with us which is material to that director’s ability to be independent from management in connection with the duties of a compensation committee member, including, but not limited to: the source of compensation of such director, including any consulting, advisory or other compensatory fee paid by us to such director; and whether such director is affiliated with us, a subsidiary of our company or an affiliate of a subsidiary of our company.

In March 2023,2024, our Board undertook a review of the independence of each director. Based upon information requested from and provided by each director concerning his or her background, employment and affiliations, including family relationships, our Board has determined that each of Ms. Hong, Dr. Lupher, Mr. Machado, Dr. Nicholson, Dr. Ozden, Mr. Scopa, Ms. Svoronos, Dr. Tuckson, and Dr. Whitcup is independent within the meaning of Rule 5605 of the Nasdaq Listing Rules. Our Board also determined that Mr. Machado, Mr. Scopa, and

In accordance with our amended and restated certificate of incorporation, our Board is divided into three classes with staggered three-year terms. At each annual meeting of stockholders, the successors to directors whose terms then expire will be elected to serve from the time of election and qualification until the third annual meeting following their election.

We feel strongly that, given the long runway for drug therapy development and given the stage and size of the Adverum, as well as our current priority focus on restoring the clinical trials roadmap in support of our long-term growth, a classified Board is appropriate at the current time.

Our amended and restated Bylaws and Corporate Governance Guidelines provide our Board with flexibility to combine or separate the positions of Chair of the Board and Chief Executive Officer and/or appoint a lead director in accordance with its determination that utilizing one or the other structure would be in the best interests of our company. The roles of Chair of the Board and Chief Executive Officer are currently filled by Mr. Machado and Dr. Fischer, respectively. While the positions of Chief Executive Officer and Chair of the Board are currently held by different individuals, we do not believe there should be a fixed rule regarding the separation of these positions, or whether the chair should be an employee of ours or should be elected from among the non-employee directors. Our needs and the individuals available to assume these roles may require different outcomes at different times, and we and our Board believe that retaining that flexibility in these decisions is in our best interests. See “Role of Board in Risk Oversight Process” for a discussion on how our Board manages risk.

Mr. Machado has served as Chair of the Board since May 2019. Mr. Machado’s tenure on the Board, his experience in serving on multiple other biotechnology company boards, as well as the deep knowledge of our company gained in his role as a member of the Audit Committee of the Board, allow him to provide valuable insights and facilitate the implementation of our strategic initiatives and business plans. In our view, having a Chair that is far removed from management would have the potential to give rise to divided leadership, which could interfere with good decision making or weaken our ability to develop and implement strategy. The Board also believes, however, that Mr. Machado’s independence is an essential complement to his familiarity with our company and management representation on the Board, helping to foster an environment that is conducive to objective evaluation and oversight of management’s performance.

The Nominating and Corporate Governance Committee is responsible for reviewing with the Board, on an annual basis, the appropriate characteristics, skills and experience required for the Board as a whole and its individual members. In evaluating the suitability of individual candidates (both new candidates and current Board members), the Nominating and Corporate Governance Committee, in recommending candidates for election, and the Board, in approving (and, in the case of vacancies, appointing) such candidates, may take into account many factors, including: personal and professional integrity, ethics and values; experience in corporate management, such as serving as an officer or former officer of a publicly held company; strong finance experience; experience relevant to our industry; experience as a director or executive officer of another publicly held company; diversity of expertise and experience in substantive matters pertaining to our business relative to other Board members; diversity of background and perspective; and practical and mature business judgment, including the ability to make independent analytical inquiries. The Board believes that diversity of viewpoints, background, experience and other characteristics are an important part of its makeup, and it actively seeks these characteristics in

The Nominating and Corporate Governance Committee considers diversity in identifying director nominees, striving to nominate directors with a variety of individual backgrounds and complementary skills so that, as a group, the Board will possess the appropriate talent, skills and expertise to oversee Adverum’s business and operations while serving an increasingly diverse population and patient base.

In searching for qualified director candidates to fill vacancies in the Board, the Nominating and Corporate Governance Committee solicits our Board for names of potentially qualified candidates. Additionally, the Nominating and Corporate Governance Committee may request that members of the Board pursue their own business contacts for the names of potentially qualified candidates. The Nominating and Corporate Governance Committee then considers the potential pool of director candidates, selects the candidate the committee believes best meets the then-current needs of the Board, and conducts a thorough investigation of the proposed candidate’s background to ensure there is no past history that would cause the candidate not to be qualified to serve as a member of our Board.

To fulfill its responsibility to recruit and recommend to the Board nominees for election as directors, the Nominating and Corporate Governance Committee considers all qualified candidates who may be identified by any one of the following sources: current or former Board members, a professional search firm, Adverum executives or stockholders.

Stockholders who wish to make a recommendation or propose a director candidate for consideration by the Nominating and Governance Committee may do so by submitting the candidate’s name, resume and biographical information and qualifications to the attention of the Corporate Secretary, Adverum Biotechnologies, Inc., 100 Cardinal Way, Redwood City, California 94063. All recommendations received by the Corporate Secretary will be presented to the Nominating and Governance Committee for its consideration.

We may request from the nominating stockholder or nominating stockholder group such other information as may reasonably be required to determine whether each person recommended by a stockholder or stockholder group as a nominee meets any minimum requirements that may be established by our Board and to enable us to make appropriate disclosures to stockholders entitled to vote in the next election of directors. Proposed nominees are required to make themselves reasonably available to be interviewed by the Nominating and Corporate Governance Committee and members of management, as determined to be appropriate by the Nominating and Corporate Governance Committee. We will not accept a stockholder recommendation for a nominee if the recommended candidate’s candidacy or, if elected, Board membership, would violate applicable state law, federal law or the rules of any exchange or market on which our securities are listed or traded. If the proposed nomination by stockholders was made in accordance with the procedures in our amended and restated bylaws, the Nominating and Corporate Governance Committee will apply the same criteria in evaluating the proposed nominee as it would any other Board nominee candidate and will recommend to our Board whether or not the proposed stockholder nominee should be nominated by our Board and included in our proxy statement.

Stockholders who wish to nominate a director for election at an upcoming annual meeting of stockholders must comply with the advance notice provisions in our amended and restated bylaws. Each stockholder making a nomination is required to provide certain information, representations and undertakings as outlined in our amended and restated bylaws. The Nominating and Corporate Governance Committee will consider director candidates recommended by our stockholders. If a stockholder submits a proposed nominee, the Nominating and Corporate Governance Committee will consider the proposed nominee, along with any other proposed nominees recommended by members of the Board, in the same manner in which the Nominating and Corporate Governance Committee would evaluate its nominees for director. For a description of the proper procedure for stockholder nominations, see “Procedures for Nominations of Directors by Stockholders” in this proxy statement.

We are exposed to a number of risks, including economic, environmental, operational, and regulatory risks, as well as risks resulting from the COVID-19 pandemic, among others. Risk assessment and oversight are an integral part of our governance and management processes. Our Board encourages management to promote a culture that incorporates risk management into our corporate strategy and

Our Board does not have a standing risk management committee, but rather administers this oversight function directly through our Board as a whole, as well as through various standing committees of our Board that address risks inherent in their respective areas of oversight. In particular, our Board is responsible for monitoring and assessing strategic risk exposure and key enterprise risks, and our Audit Committee is responsible for overseeing our major financial risk exposures and the steps our management has taken to monitor and control these exposures. The Audit Committee also monitors compliance with legal and regulatory requirements. Our Nominating and Corporate Governance Committee monitors the effectiveness of our corporate governance guidelines. Our Compensation Committee assesses and monitors whether any of our compensation policies and programs has the potential to encourage excessive risk-taking. The Board or appropriate Board committees discuss selected risks in more detail throughout the year, including the COVID-19 pandemic and its related risks.year.

Our Board has three primary committees: the Audit Committee, the Compensation Committee and the Nominating and Corporate Governance Committee, which are described below. In addition, the Board has a Research and Development Committee.

Our Audit Committee oversees our corporate accounting and financial reporting process. Among other matters, the Audit Committee:

The current members of our Audit Committee are Mr. Machado (Chair), Mr. Scopa and Ms. Svoronos. Mr. Machado serves as the chair of the Audit Committee. All members of our Audit Committee meet the requirements for financial literacy under the applicable rules and regulations of the SEC and the Nasdaq Listing Rules. Our Board has determined that Mr. Machado is an Audit Committee financial expert as defined under the applicable rules of the SEC and has the requisite financial sophistication as defined under the Nasdaq Listing Rules.

The Audit Committee operates under a written charter that satisfies the applicable rules and regulation of the SEC and the Nasdaq Listing Rules. A copy of the Audit Committee charter is available on our website at http://investors.adverum.com.

Our Compensation Committee reviews and approves, or may recommend to the full Board or independent members of the Board, as applicable, policies relating to compensation and benefits of our officers, directors and employees. The Compensation Committee reviews and approves corporate goals and objectives relevant to compensation of our Chief Executive Officer and other executive officers, evaluates the performance of these officers in light of those goals and objectives, and sets or makes recommendations to our Board regarding the compensation of these officers based on such evaluations. Our Board retains the authority to determine and approve, upon the recommendation of the Compensation Committee, the compensation of the Chief Executive Officer, unless such authority has been delegated to the Compensation Committee. The Compensation Committee also approves grants of stock options and other awards under our stock plans. In fulfilling its responsibilities, the Compensation Committee may delegate any or all of its responsibilities to a subcommittee of the Compensation Committee, but only to the extent consistent with our amended and restated certificate of incorporation, amended and restated bylaws, applicable Nasdaq Listing Rules, and other applicable law. The Compensation Committee will periodically review and evaluate the performance of the Compensation Committee and its members, including an annual review of its charter. The current members of our Compensation Committee are Mr. Scopa (Chair), Ms. Hong, Mr. Machado and Dr. Tuckson.

Each of the current members of our Compensation Committee is independent under the Nasdaq Listing Rules and regulations and is a “non-employee director” as defined in Rule 16b-3 promulgated under the Exchange Act.

Since 2019, Radford, a national executive compensation consulting firm, which is part of the Rewards Solutions practice at Aon plc, has been engaged by the Compensation Committee to conduct market research and analysis to assist the Compensation Committee in developing appropriate compensation and incentives for our executive officers, to advise the Compensation Committee and provide ongoing recommendations regarding material executive compensation decisions, and to review compensation proposals from management. Radford reports directly to the Compensation Committee and does not provide any non-compensation-related services to us. After review and consultation with Radford, the Compensation Committee determined that Radford is independent and that there is no conflict of interest resulting from retaining Radford. In reaching these conclusions, our Compensation Committee considered the factors set forth in SEC rules and the Nasdaq Listing Rules.

Our executive officers submit proposals to our Board and Compensation Committee regarding our executive and director compensation. Our Chief Executive Officer provides feedback and recommendations to our Compensation Committee with respect to executive compensation, other than his own compensation, including with regard to senior executive performance, responsibility and experience levels. The Compensation Committee often takes into consideration both our Chief Executive Officer’s input and the input of other senior executives in setting compensation levels.

The Compensation Committee operates under a written charter that satisfies the applicable rules and regulations of the SEC and the Nasdaq Listing Rules. A copy of the Compensation Committee charter is available on our website at http://investors.adverum.com.

The Nominating and Corporate Governance Committee is responsible for making recommendations to our Board regarding candidates for directorships and composition and organization of our Board. In addition, the Nominating and Corporate Governance Committee is responsible for overseeing our corporate governance policies and reporting and making recommendations to our Board concerning governance matters. The current members of our Nominating and Corporate Governance Committee are Ms. Svoronos (Chair), Dr. Lupher, Dr. Tuckson and Dr. Whitcup. Each of the members of our Nominating and Corporate Governance Committee is an independent director under the Nasdaq Listing Rules.

The Nominating and Corporate Governance Committee operates under a written charter. A copy of the Nominating and Corporate Governance Committee charter is available on our website at http://investors.adverum.com.

During 2022,2023, our Board met sixfour times, the Audit Committee met four times, the Compensation Committee met fivenine times, the Nominating and Corporate Governance Committee met fivefour times and the Research and Development Committee met one time.twice. In 2022,2023, each director attended at least 75% of the meetings of our Board and the committees on which the director served that were held while the person was a member of the applicable committee.

Our amended and restated certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law. Consequently, our directors will not be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for:

Our amended and restated certificate of incorporation and amended and restated bylaws provide that we are required to indemnify our directors and officers, in each case to the fullest extent permitted by Delaware law. Our amended and restated bylaws also provide that we are obligated to advance expenses incurred by a director or officer in advance of the final disposition of any action or proceeding, and permit us to secure insurance on behalf of any officer, director, employee or other agent for any liability arising out of his or her actions in that capacity regardless of whether we would otherwise be permitted to indemnify him or her under Delaware law. We have entered, and expect to continue to enter, into agreements to indemnify our directors, executive officers and other employees as determined by our Board. We have entered into an indemnification agreement with each of our directors, including each of our Board's nominees for director. With specified exceptions, these agreements provide for indemnification for related expenses, including, among other things, attorneys’ fees, judgments, fines and settlement amounts incurred by any of these individuals in any action or proceeding. We believe that these bylaw provisions and indemnification agreements are necessary to attract and retain qualified persons as directors and officers. We also maintain directors’ and officers’ liability insurance.

The limitation of liability and indemnification provisions in our amended and restated certificate of incorporation and amended and restated bylaws may discourage stockholders from bringing a lawsuit against our directors and officers for breach of their fiduciary duty. They may also reduce the likelihood of derivative litigation against our directors and officers, even though an action, if successful, might benefit us and our stockholders. Further, a stockholder’s investment may be adversely affected to the extent that we pay the costs of settlement and damages. To the extent the indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

Although our directors are encouraged to attend our annual meetings, attendance is not mandatory. AllSeven of our then current directors attended the 20222023 Annual Meeting of Stockholders. Our Board and management team encourage all of our directors to attend the virtual 20232024 Annual Meeting.

Stockholders who wish to nominate a director for election at an upcoming annual meeting of stockholders must comply with the advance notice provisions in our amended and restated bylaws. Each stockholder making a nomination is required to provide certain information, representations and undertakings as outlined in our amended and restated bylaws.

We may request from the nominating stockholder or nominating stockholder group such other information as may reasonably be required to determine whether each person proposed to be nominated by a stockholder or stockholder group meets any minimum requirements that may be established by our Board and to enable us to make appropriate disclosures to stockholders entitled to vote in the next election of directors. Proposed nominees are required to make themselves reasonably available to be interviewed by the Nominating and Corporate Governance Committee and members of management, as determined to be appropriate by the Nominating and Corporate Governance Committee. We will not accept a stockholder nomination if the nominee’s candidacy or, if elected, Board membership would violate applicable state law, federal law or the rules of any exchange or market on which our securities are listed or traded. If the proposed nomination by stockholders was made in accordance with the procedures in our bylaws, the Nominating and Corporate Governance Committee will apply the same criteria in evaluating the proposed nominee as it would any other Board nominee candidate and will recommend to our Board whether or not the proposed stockholder nominee should be nominated by our Board and included in our proxy statement.

Notices of nominations should be directed to the attention of the Corporate Secretary, Adverum Biotechnologies, Inc., 100 Cardinal Way, Redwood City, California 94063, and must be received only during the period specified above under “When are stockholder proposals due for next year’s annual meeting?” in the section “Questions and Answers about the 20232024 Annual MeetingMeeting..”

Our insider trading policy, which applies to all of our officers, directors, and employees, prohibits hedging and monetization transactions, such as zero-cost collars and forward sale contracts, that allow individuals to continue to own the covered securities but without the full risks of ownership. Margin purchases, holding securities in a “margin account,” and pledging our securities as collateral to secure loans is also prohibited.

At Adverum, our values define how we conduct business, shape patient care, apply science to medicine, and work and grow as a company. We strive to put our corporate values into action every day - by reducing the environmental impact of our research and operations, providing safe, engaging and impactful work for our employees, and always leading with integrity.

We integrate environmental, social, and governance objectives into our decision-making with the goal of delivering long-term value to all of our stakeholders. Our leadership creates and monitors our sustainability-related programs, with our Board maintaining ultimate oversight.

Additional information regarding Adverum’s environmental and social practices is included in the “Sustainability” subsection of the “Company” section of our website. Information on our website is NOT incorporated by reference in this proxy statement.

The Compensation Committee reviews pay levels for non-employee directors periodically with assistance from its compensation consultant, Radford, which prepares a comprehensive assessment of our non-employee director compensation program. That assessment includes benchmarking of director compensation against the same peer group used for executive compensation purposes, an update on recent trends in director compensation and a review of related corporate governance best practices. Following that review, either the Compensation Committee or the Board, consistent with the recommendation of the Compensation Committee, has determined the non-employee director compensation program that will be in effect until the next such determination.

Under our non-employee director compensation policy, each non-employee director receives the following cash compensation for Board and standing committee service, as applicable:

Annual cash retainers for service as a non-employee Chair of our Board, chair of a committee or non-chair member of the committee are in addition to the annual cash retainer for service as a Board member. Cash retainers are prorated for any partial years of service. We also reimburse our non-employee directors for their reasonable out-of-pocket expenses incurred in attending Board and committee meetings.

Pursuant to our non-employee director compensation policy, the non-employee directors receive grants of non-statutory stock options under our 2014 Equity Incentive Plan (the “2014 Plan”). For purposes of these awards, a non-employee director is a director who is not employed by us. Pursuant to our non-employee director compensation policy, each non-employee director who joins the Board is automatically granted an option to purchase a number of shares of our common stock resulting in the option having a grant-date fair value (determined as provided in the plan) of $520,000, but in no event more than 80,0008,000 shares (on a Post-Reverse Split basis) (an “Initial Grant”). Initial Grants vest ratably in annual installments over three years of service following the date of grant. In addition, pursuant to our non-employee director compensation policy, on the date of our annual meeting of stockholders, (i) each non-employee director receives an annual equity award under our 2014 Plan of an option to purchase a number of shares of our common stock resulting in the option having a grant-date fair value of $260,000, but in no event more than 40,0004,000 shares (on a Post-Reverse Split basis) (a “Board Annual Award”) and (ii) the Chair of the Board receives an additional option to purchase a number of shares of our common stock resulting in the option having a grant-date fair value of $90,000, but in no event more than 12,5001,250 shares (on a Post-Reverse Split basis) (a “Chair Additional Annual Award”). The Board Annual Awards and Chair Additional Annual Awards vest in full on the earlier to occur of the first anniversary of the grant date or the next annual meeting. All such options have a maximum term of ten years.

Except as set forth below, we had no transactions that have occurred since January 1, 20212022 and to which we were a party, in which the amount involved exceeded the lesser of $120,000 and 1% of the average of our total assets at year-end for the last two completed fiscal years and in which any of our directors, executive officers or holders of more than 5% of our capital stock, or an affiliate or immediate family member thereof, at any time from January 1, 20212022 to the date of this report, had or will have a direct or indirect material interest, other than those already described in this proxy statement under the headings “Non-Employee Director Compensation” and “Executive Compensation.”

In November 2022, we entered into a consulting agreement with FLG Partners, LLC (“FLG Partners”) pursuant to which FLG Partners provided us with consulting services. Pursuant to the consulting agreement, Linda Rubinstein has served as our Chief Financial Officer since December 2022. In 2022,2023, we paid FLG Partners $111,888, $10,000 of which was a refundable deposit,$674,863 for consulting services under the consulting agreement, including for the services of Ms. Rubinstein. Concurrent with Ms. Rubinstein’s acceptance of and conversion to full time employment with the Company in August 2023, the consulting agreement with FLG Partners was mutually terminated by the company and FLG Partners.

Our Board has adopted a written related person transaction policy to set forth the policies and procedures for the review and approval or ratification of related person transactions. This policy covers, with certain exceptions set forth in Item 404 of Regulation S-K, any transaction, arrangement or relationship, or any series of similar transactions, arrangements or relationships in which we were or are to be a participant, where the amount involved exceeds $120,000 and a related person had, has or will have a direct or indirect material interest, including, without limitation, purchases of goods or services by or from the related person or entities in which the related person has a material interest, indebtedness and guarantees of indebtedness.

As provided by our related party transaction policy, our Audit Committee will be responsible for reviewing and approving in advance the related person transaction and in doing so will consider all relevant facts and circumstances, including, but not limited to, whether the transaction is on terms comparable to those that could be obtained in an arm’s-length transaction and the extent of the related person’s interest in the transaction.

Our executive officers are appointed by and serve at the discretion of the Board. There are no family relationships among our directors and executive officers. The following table provides information regarding our executive officers, including their ages and positions, as of April 15, 2023:22, 2024:

A brief biography of each of our executive officers appears below, except for Dr. Fischer, whose biographical information appears above under “Proposal No. 1: Election of Directors—Class“Class II Directors”Directors” above.

This Compensation Discussion and Analysis provides information regarding Adverum’s compensation philosophy, policies and practices, and includes information about the 20222023 compensation paid or earned by those individuals who served as our Named Executive Officers, or NEOs, during the year ended December 31, 2022.2023. These individuals were as follows:

Adverum Biotechnologies is a clinical-stage company that aims to establish gene therapy as a new standard of care for highly prevalent ocular diseases with the aspiration of developing functional cures to restore vision and prevent blindness. Leveraging the capabilities of its proprietary intravitreal (IVT) AAV.7m8 ocular gene therapy platform, Adverum is developing durable, single-administration therapies, designed to be delivered in physicians’ offices, to eliminate the need for frequent ocular injections to treat these diseases. Adverum is developing ixoberogene soroparvovec (Ixo-vec, formerly referred to as ADVM-022), its novel clinical-stage gene therapy product candidate, as a one-time, IVT injection for patients with neovascular or wet age-related macular degeneration (“wet AMD”). Ixo-vec utilizes a proprietary vector capsid, AAV.7m8, carrying an aflibercept coding sequence under the control of a proprietary expression cassette. By overcoming the challenges associated with current treatment paradigms for debilitating ocular diseases, Adverum aspires to transform the standard of care, preserve vision, and create a profound societal impact around the globe.

The perspectives we heard from our stockholders were conveyed to all members of the Board of Directors and were reviewed and considered by the relevant Board committees. Below is a summary of the feedback we received since our 2022 Annual Meeting and how we have responded:

The Compensation Committee of our Board of Directors oversees our executive compensation program and is responsible for reviewing and approving all compensation of our executive officers, including our NEOs, authorizing stock incentive compensation, approving other incentive arrangements, and authorizing related agreements. During the fourth quarter of the year, the Compensation Committee meets to begin planning for executive compensation for the followingnext year. Its activities include undertaking a preliminary assessment of the goals achievement for the current calendar year, settingcompensation analysis and comparison with our compensation peer group, reviewing current market data with respect to cash and equity compensation of our executives and establishing the performance measures which will be used to determine eachthe executive officer’sofficers’ annual cash bonus opportunities during the following year. In the first quarter of the year, the Compensation Committee meets to review and approve the achievement level of our prior year goals, sets the executive officers’ base salaries, and target annual cash and equity incentive opportunities in alignment with our overall compensation philosophy.

Pursuant to our annual cash incentive program, our Named Executive OfficersNEOs are eligible to receive performance-based cash incentives based on the achievement of certain pre-established performance objectives that include corporate and individual performance goals. The annual incentive for our Chief Executive Officer and our NEOs is based exclusively on the corporate metrics, without an individual performance component. For other NEOs, the corporate and individual objectives were assigned a 75% and 25% weighting, respectively, in 2022; however, for 2023, all NEOs’ annual incentive will be based exclusively on the corporate metrics.

Each NEO’s target bonus opportunity for 20222023 was expressed as a percentage of base salary as presented below.

Our 20222023 annual incentive program was designed to incentivize progress on our strategic priorities, including an emphasis on starting and enrolling the LUNA trial. Our 2022 annual incentive program comprised two separate half-yearThe table below outlines the weighting of 2023 performance periods as a result of a mid-year re-evaluation and a focus shift to our strategic priorities after the restructuring that occurred in 2022. Following the restructuring, our incentive program placed higher weighting on key priorities tied to clinical and regulatory milestones.goals.

At the end of the year, the Compensation Committee assessed the achievement of our corporate performance goals during the first and second halves of the performance period against corresponding performance goals. In evaluating the NEOs’ success against the corporate goals, the Compensation Committee considered and assessed the company’s achievement against the goals in place through the first half of the year at 100% and, following the re-evaluation and focusing of our strategic priorities, the goals in place through the second half of the year at 70%. These assessments balanced our successfulprogress with LUNA, regulatory interactions, initiation of LUNA, CMC developments, scientific achievements, employee retention and financial metrics, against targeted clinical and regulatory milestones for Ixo-vec in the second half of the year.

In the first quarter of 2022,2023, we granted the NEOs long-term equity awards that were delivered in the form of stock options, and performance stock units, as follows:follows (all information presented in the table below is on a Post-Reverse Split basis):