UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the Registrant  ☒                             Filed by a Party other than the Registrant  ☐

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☐	Preliminary Proxy Statement
☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☐	Definitive Proxy Statement
☒	Definitive Additional Materials
☐	Soliciting Material Pursuant to §240.14a-12

AVROBIO, INC.

(Exact name of registrant as specified in its charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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Important Notice Regarding the Availability of Proxy Materials for the AVROBIO, Inc. Stockholder Meeting to be held on June 4, 2020 at 8:00 a.m. (Eastern Time) This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. To view the proxy statement and annual report, go to www.proxydocs.com/AVRO. To submit your proxy while visiting this site, you will need the 12 digit control number in the box below. Under United States Securities and Exchange Commission rules, proxy materials do not have to be delivered in paper. Proxy materials can be distributed by making them available on the Internet. We have chosen to use these procedures for our Annual Meeting and need YOUR participation. If you want to receive a paper or e-mail copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. In order to receive a paper package in time for this year’s annual meeting, please make this request on or before May 22. For a Convenient Way to VIEW Proxy Materials – and – VOTE Online go to: www.proxydocs.com/AVRO Proxy Materials Available to View or Receive: 1. Annual Report 2. Notice & Proxy Statement Printed materials may be requested by one of the following methods: INTERNET www.investorelections.com/AVRO TELEPHONE (866) 648-8133 *E-MAIL paper@investorelections.com You must use the 12 digit control number located in the shaded gray box below. * If requesting material by e-mail, please send a blank e-mail with the 12 digit control number (located below) in the subject line. No other requests, instructions or other inquiries should be included with your e-mail requesting material. AVROBIO, Inc. Notice of Annual Meeting Meeting Type: For holders as of: Date: Time: Place: Annual Meeting April 6, 2020 Thursday, June 4, 2020 8:00 a.m. (Eastern Time) Annual Meeting to be held live via the Internet - please visit www.proxydocs.com/AVRO for more details. The Board of Directors Recommends a Vote FOR the nominees listed in proposal 1. 1. To elect two class II directors to our board of directors, to serve until the 2023 Annual Meeting of Stockholders. (1) Ian Clark (2) Annalisa Jenkins The Board of Directors Recommends a Vote FOR proposal 2. 2. To ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2020. The Board of Directors Recommends a Vote FOR proposal 3. 3. To approve an amendment to the AVROBIO, Inc. 2018 Stock Option and Incentive Plan. Note: To transact any other business that may properly come before the annual meeting or any adjournment thereof. In order to attend, you must register in advance at www.proxydocs.com/AVRO prior to the deadline of June 2, 2020 at 5:00 pm Eastern Time. Upon completing your registration, you will receive further instructions via email, including your unique links that will allow you access to the meeting and will also permit you to submit questions. Please be sure to follow instructions found on your Proxy Card and/or Voting Authorization Form and subsequent instructions that will be delivered to you via email.