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  ☐

Check the appropriate box:

☐	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 under §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)

Payment of Filing Fee (Check all boxes that apply):

☒	No fee required
☐	Fee paid previously with preliminary materials
☐	Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

Have the 12 digit control number located in the shaded box above available when you access the website and follow the instructions. When requesting via the Internet or telephone you will need the 12 digit control number located in the shaded box above. * If requesting material by e-mail, please send a blank e-mail with the 12 digit control number (located above) in the subject line. No other requests, instructions OR other inquiries should be included with your e-mail requesting material. AVROBIO, Inc. Meeting Type: Date: Time: Place: Annual Meeting of Stockholders Wednesday, June 8, 2022 9:00 AM, Eastern Time Annual Meeting to be held live via the internet - please visit www.proxydocs.com/AVRO for more details You must register to attend the meeting online and/or participate at www.proxydocs.com/AVRO SEE REVERSE FOR FULL AGENDA INTERNET www.investorelections.com/AVRO TELEPHONE (866) 648-8133 * E-MAIL paper@investorelections.com To order paper materials, use one of the following methods. For a convenient way to view proxy materials and VOTE go to www.proxydocs.com/AVRO 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 meeting, you must make this request on or before May 27, 2022. AVROBIO, Inc. Important Notice Regarding the Availability of Proxy Materials Annual Meeting of Stockholders to be held on June 8, 2022 For stockholders of record at the close of business on This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. This is not a ballot. You cannot use this notice to vote your shares. We encourage you to access and review all of the important information contained in the proxy materials before voting. To view the proxy materials and to obtain instructions on how to attend the meeting, go to: www.proxydocs.com/AVRO To vote 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. P.O. BOX 8016, CARY, NC 27512-9903 (Company Logo)

AVROBIO, Inc. Annual Meeting of Stockholders PROPOSAL 1. To elect three class I directors to our board of directors, to serve until the 2025 annual meeting of stockholders and until his or her successor has been duly elected and qualified, or until his or her earlier death, resignation or removal. 1.01 Gail Farfel, Ph.D. 1.02 Christopher Paige, Ph.D. 1.03 Philip Vickers, Ph.D. THE BOARD OF DIRECTORS RECOMMENDS A VOTE FOR PROPOSALS 2 AND 3. 2. To ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2022. 3. To approve an amendment to the AVROBIO, Inc. 2018 Stock Option and Incentive Plan. Note: To transact any other business properly brought before the Annual Meeting or any adjournment or postponement of the Annual Meeting. THE BOARD OF DIRECTORS RECOMMENDS A VOTE FOR EACH OF THE NOMINEES LISTED IN PROPOSAL 1.