X0306 4 2019-06-11 0 0001681087 AVROBIO, Inc. AVRO 0001451612 Booth Bruce C/O AVROBIO, INC. ONE KENDALL SQUARE, BLDG 300, STE 201 CAMBRIDGE MA 02139 1 0 0 0 Stock Option (Right to Buy) 13.60 2019-06-11 4 A 0 9675 0.00 A 2029-06-10 Common Stock 9675 9675 D The option shall vest in full upon the earlier of June 11, 2020 or the date of the Issuer's 2020 Annual Meeting of Stockholders, subject to the reporting person's continued service as a director through such vesting date. This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Life Science Advisors, LLC and as such, the Reporting Person disclaims ownership of such securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any. /s/Bruce Booth 2019-06-13