PROXY STATEMENT

AVIDITY BIOSCIENCES, INC.

10578 Science Center Drive, Suite 125, La Jolla, California 92121

General

This proxy statement is furnished in connection with the solicitation by the board of directors (the “Board”) of Avidity Biosciences, Inc. of proxies to be voted at our Annual Meeting of Stockholders to be held virtually on Wednesday, June 15, 2022 (the “Annual Meeting”), at 9:00 a.m., Pacific Time, and at any continuation, postponement or adjournment thereof. Holders of record of shares of our common stock, $0.0001 par value per share (“Common Stock”), as of the close of business on April 18, 2022 (the “Record Date”), will be entitled to notice of and to vote at the Annual Meeting and any continuation, postponement or adjournment thereof. As of the Record Date, there were 49,763,363 shares of our Common Stock outstanding and entitled to vote at the Annual Meeting. Each share of Common Stock is entitled to one vote on any matter presented to stockholders at the Annual Meeting.

This proxy statement and the Company’s Annual Report to Stockholders for the year ended December 31, 2021 (the “2021 Annual Report”), or Notice of Internet Availability of Proxy Materials, as applicable, will be sent on or about May 3, 2022 to our stockholders on the Record Date.

In this proxy statement, “Avidity,” the “Company,” “we,” “us” and “our” refer to Avidity Biosciences, Inc.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS

FOR THE STOCKHOLDER MEETING TO BE HELD ON WEDNESDAY, JUNE 15, 2022:

This Proxy Statement and our 2021 Annual Report to Stockholders are available at:

www.proxydocs.com/RNA.

PROPOSALS

At the Annual Meeting, our stockholders will be asked:

We currently know of no other business that will be presented at the Annual Meeting. If any other matter properly comes before the stockholders for a vote at the Annual Meeting, however, the proxy holders named on the Company’s proxy card will vote your shares in accordance with their best judgment.

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RECOMMENDATIONS OF THE BOARD

The Board recommends that you vote your shares as indicated below. If you return a properly completed proxy card, or vote your shares by telephone or Internet, your shares of Common Stock will be voted on your behalf as you direct. If not otherwise specified, the shares of Common Stock represented by the proxies will be voted, and the Board recommends that you vote, as follows:

If any other matter properly comes before the stockholders for a vote at the Annual Meeting, the proxy holders named on the Company’s proxy card will vote your shares in accordance with their best judgment.

INFORMATION ABOUT THIS PROXY STATEMENT

Why you received this proxy statement. You are viewing or have received these proxy materials because the Board is soliciting your proxy to vote your shares at the Annual Meeting. This proxy statement includes information that we are required to provide to you under the rules of the Securities and Exchange Commission (“SEC”) and that is designed to assist you in voting your shares.

Notice of Internet Availability of Proxy Materials. As permitted by SEC rules, we are making this proxy statement and our 2021 Annual Report available to our stockholders electronically via the Internet. On or about May 6, 2022, we will mail to our stockholders a Notice of Internet Availability of Proxy Materials (the “Internet Notice”) containing instructions on how to access this proxy statement and our 2021 Annual Report and vote online. If you received an Internet Notice by mail, you will not receive a printed copy of the proxy materials in the mail unless you specifically request them. Instead, the Internet Notice instructs you on how to access and review all of the important information contained in the proxy statement and 2021 Annual Report. The Internet Notice also instructs you on how you may submit your proxy over the Internet. If you received an Internet Notice by mail and would like to receive a printed copy of our proxy materials, you should follow the instructions for requesting such materials contained on the Internet Notice. We encourage our stockholders to take advantage of the availability of the proxy materials on the Internet to help reduce the environmental impact of its annual meetings and reduce the cost to us associated with the printing and mailing of materials.

Printed Copies of Our Proxy Materials. If you received printed copies of our proxy materials, then instructions regarding how you can vote are contained on the proxy card included in the materials.

Householding. The SEC’s rules permit us to deliver a single Internet Notice or set of proxy materials to one address shared by two or more of our stockholders. This delivery method is referred to as “householding” and can result in significant cost savings. To take advantage of this opportunity, we have delivered only one Internet Notice or one set of proxy materials to multiple stockholders who share an address, unless we received contrary instructions from the impacted stockholders prior to the mailing date. We agree to deliver promptly, upon written or oral request, a separate copy of the Internet Notice or proxy materials, as requested, to any stockholder at the shared address to which a single copy of those documents was delivered. If you prefer to receive separate copies of the Internet Notice or proxy materials, we will provide copies of these documents, free of charge, upon written request to Avidity Biosciences, Inc., 10578 Science Center Drive, Suite 125, San Diego, California 92121, Attention: Corporate Secretary or by calling (858) 401-7900. Such requests by street name holders should be made through their bank, broker or other holder of record.

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Stockholders sharing an address that are receiving multiple copies of the Internet Notice can request delivery of a single copy of the proxy statement or annual report or Internet Notice by contacting their broker, bank or other intermediary or sending a written request to Avidity Biosciences, Inc. at the above address or by calling (858) 401-7900.

Questions and Answers about the Annual Meeting of Stockholders

Who is entitled to vote on matters presented at the Annual Meeting?

The Record Date for the Annual Meeting is April 18, 2022. You are entitled to vote on the matters presented at the Annual Meeting if you were a record holder at the close of business on the Record Date. Each outstanding share of Common Stock is entitled to one vote for all matters before the Annual Meeting. At the close of business on the Record Date, there were 49,763,363 shares of Common Stock outstanding and entitled to vote at the Annual Meeting. Common Stock is our only class of stock entitled to vote.

What is the difference between being a “Record Holder” and holding shares in “Street Name”?

If, on the Record date, your shares were registered directly in your name then you are a stockholder of record.

If, on the Record Date, your shares were held in an account at a brokerage firm, bank, dealer or other similar organization, then you are the beneficial owner of shares held in “street name” and these proxy materials are being forwarded to you by that organization. The organization holding your account is considered the stockholder of record for purposes of voting at the Annual Meeting.

Am I entitled to vote if my shares are held in “Street Name”?

Yes. If your shares are held in street name, these proxy materials, along with instructions on how to vote your shares, are being provided to you by your brokerage firm, bank, dealer or other similar organization. As the beneficial owner, you have the right to direct your brokerage firm, bank, dealer or other similar organization how to vote your shares, and the brokerage firm, bank, dealer or other similar organizations is required to vote your shares in accordance with your instructions. If your shares are held in street name, you may not vote your shares in person at the Annual Meeting, unless you obtain, and present at the Annual Meeting, a legal proxy from your brokerage firm, bank, dealer or other similar organization.

How many shares must be present to hold the Annual Meeting?

A quorum must be present at the Annual Meeting for any business to be conducted. Under Delaware law and our Amended and Restated Bylaws (the “Bylaws”), the presence at the Annual Meeting online, or by proxy, of the holders of a majority in voting power of the Common Stock issued and outstanding and entitled to vote, on the Record Date will constitute a quorum for the transaction of business at the Annual Meeting. The inspector of election will determine whether a quorum is present and will tabulate the votes cast at the Annual Meeting.

How can I attend the Annual Meeting of Stockholders?

As noted above, we have decided to hold the Annual Meeting entirely online this year. You may attend the Annual Meeting only if you are a record holder or beneficial owner of our Common Stock as of the Record Date. If you are a record holder you are entitled to vote at the Annual Meeting. If you hold your shares in street name you must obtain a valid proxy from your brokerage firm, bank, dealer or other similar organization to vote at the Annual Meeting. To attend and participate in the Annual Meeting, you will need the Control Number included in your Internet Notice, your proxy card or on the instructions that accompanied your proxy materials. If your shares are held in “street name,” you should contact your bank or broker to obtain your Control Number or otherwise vote through the bank or broker. To be admitted to the Annual Meeting and vote your shares, you must register to

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attend the annual meeting at www.proxydocs.com/RNA and provide the Control Number by 2:00 p.m. Pacific Time on June 13, 2022. After completion of your registration, further instructions, including a unique link to access the annual meeting, will be emailed to you.

Will there be a question and answer session during the Annual Meeting?

This year’s stockholder question and answer session will include questions submitted in advance of the annual meeting. You may submit a question in advance of the meeting as a part of the registration process. Questions pertinent to meeting matters and that are submitted in accordance with our Rules of Conduct for the annual meeting will be answered during the meeting, subject to applicable time constraints. Questions and answers may be grouped by topic and substantially similar questions may be grouped and answered once. In order to promote fairness, efficient use of time and in order to ensure all stockholders are responded to, we will respond to up to two questions from a single stockholder.

What if a quorum is not present at the Annual Meeting?

If a quorum is not present at the scheduled time of the Annual Meeting, (i) the Chairperson of the Annual Meeting or (ii) the holders of a majority of the shares entitled to vote, present at the virtual meeting, or represented by proxy, at the virtual meeting are authorized by our Amended and Restated Bylaws to adjourn the Annual Meeting until a quorum is present or represented.

What does it mean if I receive more than one Internet Notice or more than one set of Proxy Materials?

It means that your shares are held in more than one account at the transfer agent and/or with banks or brokers. Please vote all of your shares. To ensure that all of your shares are voted, for each Internet Notice or set of proxy materials, please submit your proxy by phone, via the Internet or, if you received printed copies of the proxy materials, by signing, dating and returning the enclosed proxy card in the enclosed envelope.

How do I vote?

With respect to the election of directors, you may either vote “For” all the nominees to the Board or you may “Withhold” your vote for any nominee you specify. With respect to the ratification of the appointment of BDO USA, LLP as our independent registered public accounting firm, you may vote “For,” “Against” or “Abstain” from voting.

Stockholders of Record: Shares Registered in Your Name

If you are a stockholder of record, there are several ways for you to vote your shares. Whether or not you plan to attend the virtual Annual Meeting, we urge you to vote by proxy prior to the Annual Meeting to ensure that your vote is counted.

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Beneficial Owners: Shares Registered in the Name of a Broker, Bank or Other Agent

If you are a beneficial owner of shares registered in the name of your broker, bank or other agent, you should have received voting instructions from that organization rather than directly from us. Please check with your bank, broker, or other agent and follow the voting instructions they provide to vote your shares. Generally, you have three options for returning your proxy.

Can I change my vote after I submit my Proxy?

Yes. If you are a record holder, you may revoke your proxy and change your vote any time before the proxy is voted at the Annual Meeting:

Your most recent proxy card or telephone or Internet proxy is the one that is counted. Your attendance at the Annual Meeting by itself will not revoke your proxy.

If your shares are held in street name, you may change or revoke your voting instructions by following the specific directions provided to you by your bank or broker, or you may vote virtually at the Annual Meeting by obtaining a legal proxy from your bank or broker and submitting the legal proxy along with your ballot at the Annual Meeting.

Who will count the votes?

A representative from Mediant Communications, Inc. is expected to tabulate and certify the votes, and an employee or representative of the Company is expected to act as inspector of election.

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What if I do not specify how my shares are to be voted?

If you are a record holder and you indicate when voting on the Internet or by telephone that you wish to vote as recommended by the Board, then your shares will be voted at the Annual Meeting in accordance with the Board’s recommendation on all matters presented for a vote at the Annual Meeting. Similarly, if you are a record holder and submit a proxy but do not indicate any voting instructions, the persons named as proxies will vote in accordance with the recommendations of the Board. The Board’s recommendations are indicated on page 1 of this proxy statement, along with the description of each proposal in this proxy statement.

If you are a beneficial owner of shares held in street name and do not provide the organization that holds your shares with specific voting instructions, then, the organization that holds your shares may generally vote your shares in their discretion on “routine” matters but cannot vote on “non-routine” matters. If the organization that holds your shares does not receive instructions from you on how to vote your shares on a non-routine matter, that organization will inform the inspector of election that it does not have the authority to vote on that matter with respect to your shares. This is generally referred to as a “broker non-vote.”

What are broker non-votes and do they count for determining a quorum?

Shares represented by proxies that reflect a broker non-vote will be counted as present for purposes of determining the presence of a quorum. As discussed above, broker non-votes occur when shares held by a broker in “street name” for a beneficial owner are not voted with respect to a particular proposal because (1) the broker has not received voting instructions from the beneficial owner and (2) the broker lacks discretionary voting power to vote those shares on a particular matter. A broker has discretionary power to vote shares without instruction from the beneficial owner on routine matters, such as the ratification of the appointment of BDO USA, LLP as our independent registered public accounting firm. Thus, broker non-votes are not expected on that proposal. On the other hand, absent instructions from the beneficial owner of such shares, a broker is not entitled to vote shares held for a beneficial owner on non-routine matters. Broker non-votes on the election of directors, which is considered a non-routine matter, will have no effect because they are not considered votes cast, and the two directors that receive the highest number of votes will be elected.

What is an Abstention and how will votes Withheld and Abstentions be treated?

Shares of common stock held by persons attending the Annual Meeting but not voting, and shares represented by proxies that reflect withheld votes or abstentions as to a particular proposal, will be counted as present for purposes of determining the presence of a quorum. A “vote withheld,” in the case of the proposal regarding the election of directors, or an “abstention,” in the case of the ratification of the appointment of BDO USA, LLP, represents a stockholder’s affirmative choice to decline to vote on a proposal. Votes withheld have no effect on the election of directors, as the two directors that receive the highest number of votes will be elected, and abstentions are not considered to be a vote cast and will have no effect on the ratification of the appointment of BDO USA, LLP.

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How many votes are required for the approval of the proposals to be voted upon and how will Abstentions and Broker Non-Votes be treated?

Will any other business be conducted at the Annual Meeting?

We currently know of no other business that will be presented at the Annual Meeting. If any other matter properly comes before the stockholders for a vote at the Annual Meeting, however, the proxy holders named on the Company’s proxy card will vote your shares in accordance with their best judgment.

Where can I find the voting results of the Annual Meeting of Stockholders?

We plan to announce preliminary voting results at the Annual Meeting and we will report the final results in a Current Report on Form 8-K, which we intend to file with the SEC within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Form 8-K within four business days after the Annual Meeting, we intend to file a Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additional Form 8-K to publish the final results.

Proposals To Be Voted On

Proposal 1 - Election of Directors

At the Annual Meeting, two (2) Class II directors are to be elected to hold office for a three-year term expiring at the Annual Meeting of Stockholders to be held in 2025 and until such director’s successor is elected and qualified or until such director’s earlier death, resignation or removal. Based on the recommendation of the Nominating and Corporate Governance Committee, the Board has nominated Tamar Thompson and Eric Mosbrooker for re-election as Class II directors at the Annual Meeting.

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The proposal regarding the election of directors requires the approval of a plurality of the votes cast. This means that the two nominees receiving the highest number of affirmative “FOR” votes will be elected as Class II directors. Votes withheld and broker non-votes are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal.

Our Amended and Restated Certificate of Incorporation (the “Charter”) and Bylaws provide that the authorized number of directors shall be fixed from time to time exclusively by resolution adopted by a majority of the Board. We currently have eight (8) authorized directors on our Board. As set forth in our Charter, the Board is currently 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 election. The following table summarizes the class, independence and committee membership of our directors:

The division of our Board into three classes with staggered three-year terms may delay or prevent a change of our management or a change in control of our Company. Our directors may be removed only for cause and only by the affirmative vote of the holders of at least two-thirds of the voting power of the then-outstanding shares of capital stock entitled to vote in the election of directors.

In the event any of the nominees should become unable to serve, or for good cause will not serve, as a director, it is intended that votes will be cast for a substitute nominee designated by the Board or the Board may elect to reduce its size. The Board has no reason to believe that the nominees named below will be unable to serve if elected. Each of the nominees has consented to being named in this proxy statement and to serve if elected.

All of the persons whose names and biographies appear below are currently serving as our directors. Each of our directors brings to the Board significant leadership experience derived from their professional experience and service as executives or board members of other corporations and/or private equity and venture capital firms. The process undertaken by the Nominating and Corporate Governance Committee in recommending qualified director candidates is described below under “Board Diversity and Director Nomination Process.” Certain individual qualifications and skills of our directors that contribute to the Board’s effectiveness as a whole are described in the following paragraphs.

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Vote required

The proposal regarding the election of directors requires the approval of a plurality of the votes cast. This means that the nominees receiving the highest number of affirmative “FOR” votes will be elected as Class II Directors. Votes withheld and broker non-votes are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal.

The Board unanimously recommends a vote FOR the election of the two nominees for Class II directors.

Information Regarding Directors

The information set forth below as to the directors and nominees for director has been furnished to us by the directors and nominees for director:

Nominees for Election to the Board:

Class II Directors (Terms to Expire at the 2025 Annual Meeting)

Erik Mosbrooker has served on our board of directors since August 2021. Since March 2021, Mr. Mosbrooker has served as Chief Operations Officer of Cognoa, Inc. Previously, Mr. Mosbrooker has served as Senior Vice President and Chief Commercial Officer of Audentes Therapeutics, Inc. from January 2019 to January 2021. From August 2018 to December 2018, Mr. Mosbrooker served first as Chief Commercial Officer and later as Chief Operating Officer at Origin Biosciences, a subsidiary of BridgeBio Pharma LLC focused on developing a rare pediatric metabolic disorder treatment. From November 2016 to April 2018, following its acquisition of Raptor Pharmaceuticals Corp, he served at Horizon Pharma plc as Group Vice President and GM and later as Senior Vice President and GM. Prior to the acquisition by Horizon Pharma, Mr. Mosbrooker served in various positions at Raptor Pharmaceuticals from November 2012, including Senior Vice President of Americas & Asia Pacific from March 2016 to November 2016. Prior to Raptor, Mr. Mosbrooker served as commercial operations and market access lead for STRENSIQ^® at Alexion Pharmaceuticals, Inc. and Enobia Pharma, Inc. He has held various commercial operational roles at Onyx Pharmaceuticals, Inc., Jazz Pharmaceuticals Inc., Chiron Corporation (now Novartis) and Millennium Pharmaceuticals, Inc. He has experience in management, healthcare and technology consulting at IBM, Teltech Resource Network Corporation and Kohler Company. Mr. Mosbrooker earned his B.S. in Industrial Engineering from the University of Wisconsin, Madison. Mr. Mosbrooker’s executive and commercial experience in the biotechnology industry contributed to our board of directors’ conclusion that he should serve as a director of our company.

Tamar Thompson has served on our board of directors since January 2021. Since November 2019, Ms. Thompson has served as the Vice President, Global Corporate Affairs for Alexion Pharmaceuticals, Inc. and as the Chair of the Board of Alexion’s Charitable Foundation. Prior to joining Alexion, Ms. Thompson served as head, federal executive branch strategy and state government affairs for Bristol-Myers Squibb Company from February 2015 to November 2019. She also served as a strategic policy advisor and consultant for premiere Washington, DC based firms, including ADVI, Kimbell and Associates and Avalere Health. Ms. Thompson holds a M.S. in Health Sciences with a concentration in Public Health from Trident University. Ms. Thompson’s extensive health policy and government affairs experience contributed to our board of directors’ conclusion that she should serve as a director of our company.

Continuing Members of the Board:

Class I Directors (Terms to Expire at the 2024 Annual Meeting)

Carsten Boess has served on our board of directors since April 2020. Mr. Boess also serves on the boards of directors of Rocket Pharmaceuticals, Inc., Achilles Therapeutics plc and Health Sciences Acquisitions Corporation

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2. Previously, Mr. Boess was the Executive Vice President of Corporate Affairs at Kiniksa Pharmaceuticals, Ltd. from August 2015 until February 2020. Before Kiniksa, Mr. Boess was the Chief Financial Officer at Alexion Pharmaceuticals from 2004 to 2005 and the Senior Vice President and Chief Financial Officer at Synageva BioPharma Corp. from 2011 until the company’s acquisition by Alexion Pharmaceuticals in 2015. Previously, Mr. Boess served in multiple roles with increasing responsibility at Insulet Corporation, including Chief Financial Officer from 2006 to 2009 and Vice President of International Operations from 2009 to 2011. Prior to that, Mr. Boess served as Executive Vice President of Finance at Serono Inc. from 2005 to 2006. In addition, he was a member of the Geneva-based World Wide Executive Finance Management Team while at Serono. Mr. Boess also held several financial executive roles at Novozymes of North America and Novo Nordisk in France, Switzerland and China. During his tenure at Novo Nordisk, he served on Novo Nordisk’s Global Finance Board. Mr. Boess received a Bachelor’s degree and Master’s degree in Economics and Finance, specializing in Accounting and Finance from the University of Odense, Denmark. Mr. Boess’ business, financial and corporate governance experience in the biotechnology industry contributed to our board of directors’ conclusion that he should serve as a director of our company.

Sarah Boyce has served as our President and Chief Executive Officer and as a member of our board of directors since October 2019. Prior to joining Avidity, she served as President and a member of the board of directors of Akcea Therapeutics, Inc. from April 2018 through September 2019, where she led the commercialization of the company’s rare disease products. Ms. Boyce served as Chief Business Officer of Ionis Pharmaceuticals, Inc. from January 2015 to April 2018, and Vice President, Head of International Business Strategy and Operations at Forest Laboratories, Inc. from 2012 to 2014. She previously held various positions with Alexion Pharmaceuticals Inc., Novartis Group AG, Bayer AG and F. Hoffmann-La Roche AG. Ms. Boyce currently serves on the boards of directors of Ligand Pharmaceuticals Incorporated and Berkeley Lights, Inc. Ms. Boyce holds a B.S. in Microbiology from the University of Manchester, England. Ms. Boyce’s knowledge of our business, as well as her extensive development, commercial and executive management experience, contributed to our board of directors’ conclusion that she should serve as a director of our company.

Troy Wilson, Ph.D., J.D., is our co-founder and has served as a member of our board of directors since November 2012. He served as Executive Chairman from February 2019 to January 2021 and has served as our Chairman since January 2021. Dr. Wilson served as our President and Chief Executive Officer from November 2012 to February 2019. He has been President and Chief Executive Officer and chairman of the board of directors of Kura Oncology, Inc. since August 2014 and has served as a member of the board of directors of Puma Biotechnology, Inc. since October 2013. He has served as Executive Chairman of the board of directors of Abintus Bio, Inc. since October 2020. He has also served as Executive Chairman of the board of directors of Wellspring Biosciences, Inc., a privately-held biopharmaceutical company, since July 2012, and has served as the sole managing member of Wellspring Biosciences’ parent company, Araxes Pharma LLC, since May 2012. Previously, Dr. Wilson served as a director of Zosano Pharma Corporation from June 2014 to October 2019. He also served as President and Chief Executive Officer of Wellspring Biosciences and Araxes Pharma from July 2012 to March 2019, and as President and Chief Executive Officer and a member of the board of directors of Intellikine, Inc. Dr. Wilson holds a J.D. from New York University and a Ph.D. in Bioorganic Chemistry and a B.A. in Biophysics from the University of California, Berkeley. Dr. Wilson’s knowledge of our business and his senior executive and board-level experience at biopharmaceutical companies contributed to our board of directors’ conclusion that he should serve as Chairman of our company.

Class III Directors (Terms to Expire at the 2023 Annual Meeting)

Noreen Henig, M.D., has served on our board of directors since August 2019. Since May 2020, Dr. Henig has served as the Chief Medical Officer of Kezar Life Sciences, Inc. Dr. Henig has also served as a member of the board of directors of Lazard Growth Acquisition Corp. I since February 2021. Previously, from July 2018 to March 2020, Dr. Henig served as the Chief Medical Officer of Breath Therapeutics GmbH, which is now Zambon SpA following an acquisition in July 2019. Previously, Dr. Henig served as the Chief Development Officer of ProQR

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Therapeutics N.V. where she oversaw preclinical and clinical drug development from March 2014 to November 2017. Before joining ProQR, Dr. Henig was Senior Director, Global Respiratory, from 2011 to 2014, and Director, Respiratory Therapeutics, from 2008 to 2011, at Gilead Sciences, Inc. Dr. Henig’s specialties as a physician include pulmonary, critical care, allergy and immunology. Dr. Henig holds an M.D. with a distinction in immunology from the Albert Einstein College of Medicine of Yeshiva University and a B.A. from Yale University. She also completed training in internal medicine at the University of California, San Francisco and in pulmonary and critical care medicine at the University of Washington. Dr. Henig’s drug development and clinical trial experience contributed to our board of directors’ conclusion that she should serve as a director of our company.

Edward M. Kaye, M.D., has served on our board of directors since August 2019. Dr. Kaye has served as the Chief Executive Officer and a member of the board of directors of Stoke Therapeutics Inc. since October 2017. Dr. Kaye joined Stoke from Sarepta Therapeutics, Inc. where he served as a member of the board of directors from September 2016 to August 2017, President and Chief Executive Officer from September 2016 to July 2017, Interim Chief Executive Officer from April 2015 to September 2016 and Chief Medical Officer from June 2011 to March 2017. From 2001 to 2011, Dr. Kaye served in various positions at Genzyme Corporation, including most recently as Group Vice President of Clinical Development. Previously, Dr. Kaye served as Chief of Biochemical Genetics at Children’s Hospital of Philadelphia, Chief of Neurology at St. Christopher’s Hospital for Children and as a member of the research staff at Massachusetts General Hospital and Tufts University Medical Center. Dr. Kaye is also a member of the board of directors of Cytokinetics, Inc. and the Massachusetts Biotechnology Council, where he serves on the Equality, Diversity and Inclusion Committee. Dr. Kaye holds an M.D. from the Loyola University Stritch School of Medicine and a B.S. in Biology/Chemistry from Loyola University. Dr. Kaye’s extensive leadership and clinical experience in the medical and biotechnology fields contributed to our board of directors’ conclusion that he should serve as a director of our company.

Jean Kim has served on our board of directors since January 2021. Ms. Kim served as a Partner at Deerfield Management Company LP from August 2006 to July 2020 where she provided extensive research and analysis on individual companies operating in the healthcare industry, with a particular focus on rare and orphan diseases. In addition, Ms. Kim incubated and founded a new gene therapy portfolio company at Deerfield Management with a novel incubator company structure focused on rare orphan monogenic diseases. Prior to joining Deerfield, she was a healthcare investment professional for six years with Merrill Lynch Ventures and a Financial Analyst in Merrill Lynch’s investment banking department. Ms. Kim received her Bachelor of Arts in English Literature and a Bachelor of Science in Biology from Stanford University. She also holds an MBA from Harvard Business School and a Master of Science degree from the Massachusetts Institute of Technology through the Biomedical Enterprise Program and was a Fulbright Scholar. Ms. Kim currently serves on the Board of Directors of Amplo Biotechnology, a gene therapy company. Ms. Kim’s years of experience investing in the biopharmaceutical industry contributed to our board of directors’ conclusion that she should serve as a director of our company.

In the event that the appointment of BDO USA, LLP is not ratified by the stockholders, the Audit Committee will consider this fact when it appoints the independent registered public accounting firm for the fiscal year ending December 31, 2023. Even if the appointment of BDO USA, LLP is ratified, the Audit Committee retains the discretion to appoint a different independent registered public accounting firm at any time if it determines that such a change is in the interest of the Company.

Vote Required

This proposal requires the affirmative vote of the holders of a majority in voting power of the votes cast affirmatively or negatively. Abstentions are not considered to be votes cast and, accordingly, will have no effect on the outcome of the vote on this proposal. Because brokers have discretionary authority to vote on the ratification of the appointment of BDO USA, LLP, we do not expect any broker non-votes in connection with this proposal.

The Board unanimously recommends a vote FOR the Ratification of the Appointment of BDO USA, LLP as our Independent Registered Public Accounting Firm.

(1) Audit fees consist of fees for the audit of our annual financial statements and internal controls over financial reporting, the review of the unaudited interim financial statements included in our quarterly reports on Form 10-Q and the issuance of consents and comfort letters in connection with registration statements.

Audit Committee Pre-Approval of Audit and Non-Audit Services

The Audit Committee has established a policy that all audit and permissible non-audit services provided by our independent registered public accounting firm will be pre-approved by the Audit Committee, and all such services were pre-approved in accordance with this policy during the fiscal year ended December 31, 2021. These services may include audit services, audit-related services, tax services and other services. The audit committee considers whether the provision of each non-audit service is compatible with maintaining the independence of our auditors. Pre-approval is detailed as to the particular service or category of services and is generally subject to a specific budget. Our independent registered public accounting firm and management are required to periodically report to the audit committee regarding the extent of services provided by the independent registered public accounting firm in accordance with this pre-approval, and the fees for the services performed to date.

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Although the vote is non-binding, our Compensation Committee and Board value the opinions of our stockholders and will consider the outcome of the vote when determining the frequency of the stockholder vote on executive compensation.

Vote Required

If a quorum is present and voting at the Annual Meeting, the alternative receiving the highest number of votes—every one year, every two years or every three years—will be the stockholders’ recommendation, on an advisory basis, of the frequency of the stockholder vote on executive compensation. Abstentions and broker non-votes will be counted only for purposes of determining a quorum. Broker non-votes will have no effect on this proposal as brokers or other nominees are not entitled to vote on such proposal in the absence of voting instructions from the beneficial owner.

The Board unanimously recommends a vote FOR EVERY ONE YEAR regarding the frequency of the stockholder vote to approve the compensation of the named executive officers as required by Section 14(A)(2) of the Exchange Act. Please note: Stockholders are not voting to approve or disapprove our Board’s recommendation regarding this proposal 4.

The following is biographical information for our executive officers other than Ms. Boyce, whose biographical information is included under “Continuing Members of the Board of Directors”.

W. Michael Flanagan, Ph.D. has served as our Chief Technical Officer since January 2021. Dr. Flanagan has extensive experience developing multiple therapeutic modalities, including RNA therapeutics, antibody drug conjugates, and bispecific antibodies. Prior to joining the Company in January 2022, Dr. Flanagan served as Senior Director and Project Team Leader, Oncology and Immunology for Genentech, Inc. from January 2012 to January 2022, where he advanced programs through late-stage research to end of Phase 2 development. Prior to Genentech, Dr. Flanagan served in roles of increasing responsibility in the biology groups at Sunesis Pharmaceuticals, Inc., Gilead Sciences, Inc. and Merck & Co. Inc., where he was Senior Director of RNA Sciences. Dr. Flanagan received a B.S. in Genetics from the University of California at Davis, a Ph.D. in Biological Sciences from the University of California at Irvine and was an American Cancer Society postdoctoral fellow at the Howard Hughes Medical Institute, Stanford University.

Arthur A. Levin, Ph.D., has served as our Chief Scientific Officer since October 2019, and prior to that as our Executive Vice President of Research and Development since October 2013. Dr. Levin has a combined three decades of experience in all aspects of drug development from discovery through drug registration and has played key roles in the development of numerous oligonucleotides. From April 2012 to January 2014, he served as Executive Vice President at miRagen Therapeutics, Inc. Prior to that, Dr. Levin held various senior management positions at Santaris Pharma A/S Corp. and Ionis Pharmaceuticals, Inc. Since September 2015, Dr. Levin has served as a member of the board of directors of Stoke Therapeutics, Inc. Dr. Levin holds a Ph.D. in Toxicology from the University of Rochester and a B.S. in Biology from Muhlenberg College.

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Michael F. MacLean has served as our Chief Financial Officer since May 2020 and as our Chief Financial and Chief Business Officer since April 2022. Most recently, Mr. MacLean served as Chief Financial Officer of Akcea Therapeutics, Inc. from September 2017 to March 2020. Prior to joining Akcea Therapeutics, from September 2015 to August 2017, Mr. MacLean was Chief Financial Officer and Executive Vice President of PureTech Health plc. Previously, Mr. MacLean was Chief Financial Officer of Iron Mountain Inc.’s North American business from July 2014 to June 2015 and was Senior Vice President, Worldwide Controller at Iron Mountain from October 2012 to June 2014. Prior to Iron Mountain, Mr. MacLean previously served as Senior Vice President of Finance and Chief Accounting Officer of Biogen Inc., where he led the company’s worldwide finance organization. Since June 2021, Mr. MacLean has also served on the board of directors of Verve Therapeutics. Mr. MacLean holds a B.S. in Accounting from Boston College.

Teresa McCarthy has served as our Chief Human Resources Officer since August 2020. Since 2002, Ms. McCarthy has advised life sciences companies as an organizational development and human resources consultant through her consulting firm, McCarthy Consultants Inc. Ms. McCarthy has also served as a lead consultant at The Leadership Edge from 2002 to 2020. Prior to consulting, Ms. McCarthy held the position of Director, Talent Development at Edwards Lifesciences from 1999 to 2001. Previously, Ms. McCarthy was Director, Employee Relations at Baxter Cardiovascular Group from 1996 to 1999 and served as Manager, Talent Development at IVAC Corporation from 1990 to 1995. Ms. McCarthy received a Bachelor of Arts in Communication from San Diego State and an M.A. in Organizational Communication from San Diego State University.

Corporate Governance

General

The Board has adopted Corporate Governance Guidelines, a Code of Business Conduct and Ethics and charters for our Nominating and Corporate Governance Committee, Audit Committee and Compensation Committee to assist the Board in the exercise of its responsibilities and to serve as a framework for the effective governance of the Company. You can access our current committee charters, our Corporate Governance Guidelines and our Code of Business Conduct and Ethics in the “Corporate Governance” section of the “Investors” page of our website located at www.aviditybiosciences.com, or by writing to our Secretary at our offices at 10578 Science Center Drive, San Diego, CA 92121. Please note, however, that the information contained on the website is not incorporated by reference in, or considered part of, this proxy statement.

Director Independence

The Board currently consists of eight members. The Board has determined that all of our directors, other than Ms. Boyce and Dr. Wilson, are independent directors in accordance with the listing requirements of the Nasdaq Global Market (“Nasdaq”). The Nasdaq independence definition includes a series of objective tests, including that the director is not, and has not been for at least three years, one of our employees and that neither the director nor any of his family members has engaged in various types of business dealings with us. In addition, as required by Nasdaq rules, the Board has made a subjective determination as to each independent director that no relationships exist, which, in the opinion of the Board, would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In making these determinations, the Board reviewed and discussed information provided by the directors and us with regard to each director’s business and personal activities and relationships as they may relate to us and our management. There are no family relationships among any of our directors or executive officers.

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Board Diversity and Director Nomination Process

Our 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 members) for election or appointment, the Nominating and Corporate Governance Committee, in recommending candidates for election, and the Board will take into account many factors, including the following:

Currently, the Board evaluates each individual in the context of the Board as a whole, with the objective of assembling a group that can best maximize the success of the business and represent stockholder interests through the exercise of sound judgment using its diversity of experience in these various areas.

Other than the foregoing, there are no stated minimum criteria for director nominees, although the Nominating and Corporate Governance Committee may also consider such other factors as it may deem to be in the best interests of our company and our stockholders. The Nominating and Corporate Governance Committee does, however, believe it appropriate for at least one member of our Board to meet the criteria for an “audit committee financial expert” as defined by SEC rules, and that a majority of the members of our Board meet the definition of “independent director” under Nasdaq qualification standards. The nominating and corporate governance committee also believes it is appropriate for our President and Chief Executive Officer to serve as a member of our Board. The Board currently includes four female members and two members who each self-identify as a member of an underrepresented community.

The following Board Diversity Matrix presents our Board diversity statistics in accordance with Nasdaq Rule 5606, as self-disclosed by our directors.

Identification and Evaluation of Nominees for Directors

The Nominating and Corporate Governance Committee identifies nominees for director by first evaluating the current members of our Board willing to continue in service. Current members with qualifications and skills that are consistent with the Nominating and Corporate Governance Committee’s criteria for board of director service

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and who are willing to continue in service are considered for re-nomination, balancing the value of continuity of service by existing members of our Board with that of obtaining a new perspective or expertise.

If any member of our Board does not wish to continue in service or if our Board decides not to re-nominate a member for re-election or if the Board decides to expand the size of the board, the Nominating and Corporate Governance Committee identifies the desired skills and experience of a new nominee in light of the criteria above. The Nominating and Corporate Governance Committee generally polls our Board and members of management for their recommendations. The Nominating and Corporate Governance Committee may also review the composition and qualification of the boards of directors of our competitors and may seek input from industry experts or analysts. The Nominating and Corporate Governance Committee reviews the qualifications, experience and background of the candidates. Final candidates are interviewed by the members of the Nominating and Corporate Governance Committee and by certain of our other independent directors and executive management. In making its determinations, the Nominating and Corporate Governance Committee evaluates each individual in the context of our Board as a whole, with the objective of assembling a group that can best contribute to the success of our company and represent stockholder interests through the exercise of sound business judgment. After review and deliberation of all feedback and data, the Nominating and Corporate Governance Committee makes its recommendation to our Board.

The Nominating and Corporate Governance Committee evaluates nominees recommended by stockholders in the same manner as it evaluates other nominees. We have not received director candidate recommendations from our stockholders, and we do not have a formal policy regarding consideration of such recommendations. However, any recommendations received from stockholders will be evaluated in the same manner that potential nominees suggested by members of our Board, management or other parties are evaluated.

Under our Bylaws, a stockholder wishing to suggest a candidate for director should write to our Secretary and provide such information about the stockholder and the proposed candidate as is set forth in our Bylaws and as would be required by SEC rules to be included in a proxy statement. In addition, the stockholder must include the consent of the candidate and describe any arrangements or undertakings between the stockholder and the candidate regarding the nomination. In order to give the Nominating and Corporate Governance Committee sufficient time to evaluate a recommended candidate and include the candidate in our proxy statement for the 2023 annual meeting, the recommendation should be received by our Corporate Secretary at our principal executive offices in accordance with our procedures detailed in the section below entitled “Stockholder Proposals.”

Communication from Stockholders

The Board will give appropriate attention to written communications that are submitted by stockholders, and will respond if and as appropriate. Our Secretary is primarily responsible for monitoring communications from stockholders and for providing copies or summaries to the directors as he considers appropriate.

Communications are forwarded to all directors if they relate to important substantive matters and include suggestions or comments that our Secretary and Chairman of the Board consider to be important for the directors to know. In general, communications relating to corporate governance and long-term corporate strategy are more likely to be forwarded than communications relating to ordinary business affairs, personal grievances and matters as to which we tend to receive repetitive or duplicative communications. Stockholders who wish to send communications on any topic to the Board should address such communications to the Board in writing: c/o Secretary, Avidity Biosciences, Inc., 10578 Science Center Drive, Suite 125, San Diego, California 92121.

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Director Attendance at Annual Meetings

Although we do not have a formal policy regarding attendance by members of our Board at our Annual Meeting, we encourage all of our directors to attend.

Board Leadership Structure - Separate Chairman

The Board is currently led by its Chairman, Troy Wilson, Ph.D., J.D. The Board recognizes that it is important to determine an optimal board leadership structure to ensure the independent oversight of management as we continue to grow. We separate the roles of Chief Executive Officer and Chairman of the Board in recognition of the differences between the two roles. The Chief Executive Officer is responsible for setting the strategic direction for our Company and the day-to-day leadership and performance of our Company, while the Chairman of the Board provides guidance to the Chief Executive Officer and presides over meetings of the full Board. We believe that this separation of responsibilities provides a balanced approach to managing the Board and overseeing our Company.

The Board has concluded that our current leadership structure is appropriate at this time. However, the Board will continue to periodically review our leadership structure and may make such changes in the future as it deems appropriate.

Role of Board in Risk Oversight Process

The Board has responsibility for the oversight of our risk management processes and, either as a whole or through its committees, regularly discusses with management our major risk exposures, their potential impact on our business and the steps we take to manage them. The risk oversight process includes receiving regular reports from Board committees and members of senior management to enable the Board to understand our risk identification, risk management and risk mitigation strategies with respect to areas of potential material risk, including operations, finance, legal, regulatory, strategic and reputational risk.

The Audit Committee reviews information regarding liquidity and operations, and oversees our management of financial risks. Periodically, the Audit Committee reviews our policies with respect to risk assessment, risk management, loss prevention and regulatory compliance. Oversight by the Audit Committee includes direct communication with our external auditors, and discussions with management regarding significant risk exposures and the actions management has taken to limit, monitor or control such exposures. The Compensation Committee is responsible for assessing whether any of our compensation policies or programs has the potential to encourage excessive risk-taking. The Nominating and Corporate Governance Committee manages risks associated with the independence of the Board, corporate disclosure practices, and potential conflicts of interest. While each committee is responsible for evaluating certain risks and overseeing the management of such risks, the entire Board is regularly informed through committee reports about such risks. Matters of significant strategic risk are considered by the Board as a whole.

Board Evaluation

Our Corporate Governance Guidelines require the Nominating and Corporate Governance Committee to oversee a periodic assessment by the Board of the Board’s performance. As provided in our Corporate Governance Guidelines, the Nominating and Corporate Governance Committee is responsible for establishing the evaluation criteria and implementing the process for such evaluation.

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Code of Ethics

We have a written Code of Business Conduct and Ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. We have posted a current copy of the code in the “Corporate Governance” section of the “Investors” page of our website located at www.aviditybiosciences.com.

In addition, we intend to post on our website all disclosures that are required by law or the listing standards of Nasdaq concerning any amendments to, or waivers from, any provision of the code.

Attendance by Members of the Board of Directors at Meetings

There were 6 meetings of the Board during the fiscal year ended December 31, 2021. With the exception of Eric Mosbrooker, who joined the Board in August 2021, during the fiscal year ended December 31, 2021, each director attended at least 75% of the aggregate of all meetings of the Board and meetings of the committees on which such director served during the period in which he or she served as a director..

Committees of the Board

The Board has established three standing committees—Audit, Compensation and Nominating and Corporate Governance—each of which operates under a charter that has been approved by the Board. All of the members of each of the Board’s three standing committees are independent as defined under the Nasdaq rules. In addition, all members of the Audit Committee meet the independence requirements for Audit Committee members under Rule 10A-3 under the Securities Exchange Act of 1934 (the “Exchange Act”).

The current members of each of the Board committees and committee Chairs are set forth in the following chart.

Audit Committee

The Audit Committee’s main function is to oversee our accounting and financial reporting processes and the audits of our financial statements. This committee’s responsibilities include, among other things:

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The members of our Audit Committee are Mr. Boess, Dr. Henig and Ms. Kim. Mr. Boess serves as the Chairperson 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 Nasdaq. The Board has determined that Mr. Boess is an “audit committee financial expert” as defined by applicable SEC rules and has the requisite financial sophistication as defined under the applicable Nasdaq rules and regulations. The Board has determined that each of Mr. Boess, Dr. Henig and Ms. Kim are independent under the applicable rules of the SEC and Nasdaq. All members of our audit committee are independent under Nasdaq rules and Rule 10A-3. The audit committee operates under a written charter that satisfies the applicable standards of the SEC and Nasdaq, which the Audit Committee will evaluate and review at least annually. The Audit Committee met 4 times during 2021. Both our external auditor and internal financial personnel meet privately with the Audit Committee and have unrestricted access to this committee.

Compensation Committee

Our Compensation Committee reviews, approves and recommends to the Board policies relating to compensation and benefits of our officers, employees and directors. The Compensation Committee approves corporate goals and objectives relevant to the compensation of our chief executive officer and other executive officers, evaluates the performance of these officers in light of those goals and objectives and approves the compensation of these officers based on such evaluations. The Compensation Committee also reviews and approves or makes recommendations to the Board regarding the issuance of stock options and other awards under our equity plan. In addition, the Compensation Committee periodically reviews and recommends to the Board compensation for service on the Board and any committees of the Board. The Compensation Committee may delegate its authority under its charter to one or more subcommittees as it deems appropriate from time to time as further described in its charter. The Compensation Committee will review and evaluate, at least annually, its charter, as well as review and evaluate, at least annually, the performance of the Compensation Committee and its members, including compliance by the compensation committee with its charter.

The Compensation Committee has retained Radford, a division of Aon Consulting, Inc. (“Radford”), as its independent compensation consultant to advise the Compensation Committee on matters pertaining to director and executive compensation, including advising as to market levels and practices, plan design and implementation, comparable company data, consulting best practices and governance principles, as well as on matters related to employee equity compensation. Radford does not provide any other services to the Company.

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The Compensation Committee has determined, and Radford has affirmed, that Radford’s work does not present any conflicts of interest and that Radford is independent. In reaching these conclusions, the Compensation Committee considered the factors set forth in Exchange Act Rule 10C-1 and Nasdaq listing standards.

The members of our compensation committee are Dr. Kaye, Mr. Mosbrooker and Ms. Thompson. Dr. Kaye serves as the Chairperson of the committee. Our Board has determined that each member of this committee is independent under the applicable rules and regulations of Nasdaq and is a “non-employee director” as defined in Rule 16b-3 promulgated under the Exchange Act. The Compensation Committee met 4 times during 2021.

None of the members of our compensation committee is currently, or has at any time been, one of our officers or employees. None of our executive officers currently serves, or has served during the past fiscal year, as a member of the board of directors or compensation committee (or other board committee performing equivalent functions or, in the absence of any such committee, the entire board of directors) of any entity that has one or more executive officers serving as a member of our board of directors or compensation committee.

Nominating and Corporate Governance Committee

The Nominating and Corporate Governance Committee is responsible for assisting the Board in discharging the Board’s responsibilities regarding the identification of qualified candidates to become board members, the selection of nominees for election as directors at our annual meetings of stockholders (or special meetings of stockholders at which directors are to be elected), and the selection of candidates to fill any vacancies on the Board and any committees thereof. In addition, the Nominating and Corporate Governance Committee is responsible for overseeing our corporate governance policies, reporting and making recommendations to the Board concerning governance matters and oversight of the evaluation of the Board. The members of our Nominating and Corporate Governance Committee are Dr. Henig, Dr. Kaye and Ms. Thompson. Dr. Henig serves as the Chairperson of the committee. The Board has determined that each member of this committee is independent under the applicable rules and regulations of Nasdaq relating to Nominating and Corporate Governance Committee independence. The Nominating and Corporate Governance Committee operates under a written charter, which the Nominating and Corporate Governance Committee will review and evaluate at least annually. The Nominating and Corporate Governance Committee met 4 times during 2021.

Compensation Discussion and Analysis

This compensation discussion and analysis discusses the material components of the executive compensation program for our executive officers who are named in the “Summary Compensation Table” below, whom we refer to as our “named executive officers.” For 2021, our named executive officers and their positions were as follows:

This compensation discussion and analysis provides an overview of our executive compensation philosophy, the overall objectives of our executive compensation program, and each compensation component that we provide. In addition, we explain how and why the compensation committee and our board of directors arrived at specific compensation policies and decisions involving our executive officers during the fiscal year ended December 31, 2021.

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