X0206 3 2018-06-20 0 0001681087 AVROBIO, Inc. AVRO 0001717728 SVLSF VI, LLC ONE BOSTON PLACE, SUITE 3900 201 WASHINGTON STREET BOSTON MA 02108 0 0 1 0 0001642251 SV Life Sciences Fund VI, L.P. ONE BOSTON PLACE, SUITE 3900 201 WASHINGTON STREET BOSTON MA 02108 0 0 1 0 0001667605 SV Life Sciences Fund VI Strategic Partners, L.P. ONE BOSTON PLACE, SUITE 3900 201 WASHINGTON STREET BOSTON MA 02108 0 0 1 0 0001717730 SV Life Sciences Fund VI (GP), L.P. ONE BOSTON PLACE, SUITE 3900 201 WASHINGTON STREET BOSTON MA 02108 0 0 1 0 Series A Preferred Stock Common Stock 9122809 I By SV Life Sciences Fund VI, L.P. Series A Preferred Stock Common Stock 312341 I By: SV Life Sciences Fund VI Strategic Partners, L.P. Series B Preferred Stock Common Stock 1808211 I By SV Life Sciences Fund VI, L.P. Series B Preferred Stock Common Stock 61908 I By: SV Life Sciences Fund VI Strategic Partners, L.P. All series of Convertible Preferred Stock shall automatically convert on a 4.132-for-1 basis into shares of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering and have no expiration date. The shares are held directly by SV Life Sciences Fund VI, L.P. ("SV Life LP"). SV Health Investors, LLC is the Manager of SV Life LP. SV Life Sciences Fund VI (GP), L.P., ("SV Fund VI GP") is the general partner of SV Life LP. The general partner of SV Fund VI GP is SVLSF VI, LLC. The members of the investment committee of SVLSF VI, LLC are Kate Bingham, Thomas Flynn, James Garvey, Eugene D. Hill, III, Paul LaViolette, and Michael Ross. Each of SV Fund VI GP, SVLSF VI, LLC and the SVLSF VI, LLC investment committee disclaims beneficial ownership of the shares owned directly by SV Life LP, except to the extent of any pecuniary interest therein. The shares are held directly by SV Life Sciences Fund VI Strategic Partners, L.P. ("SV Life SP LP"). SV Health Investors, LLC is the Manager of SV Life SP LP. SV Fund VI GP is the general partner of SV Life SP LP. The general partner of SV Fund VI GP is SVLSF VI, LLC. The members of the investment committee of SVLSF VI, LLC are Kate Bingham, Thomas Flynn, James Garvey, Eugene D. Hill, III, Paul LaViolette, and Michael Ross. Each of SV Fund VI GP, SVLSF VI, LLC and the SVLSF VI, LLC investment committee disclaims beneficial ownership of the shares owned directly by SV Life SP LP, except to the extent of any pecuniary interest therein. SV Life Sciences Fund VI, L.P., BY: SV Life Sciences Fund VI (GP), L.P., its sole General Partner, BY: SVLSF VI, LLC, its sole General Partner, By: Brent M. Faduski, Officer, /s/ Brent M. Faduski 2018-06-20 SV Life Sciences Fund VI Strategic Partners, L.P., BY: SV Life Sciences Fund VI (GP), L.P., its sole General Partner, BY: SVLSF VI, LLC, its sole General Partner, By: Brent M. Faduski, Officer, /s/ Brent M. Faduski 2018-06-20 SV Life Sciences Fund VI (GP), L.P., BY: SVLSF VI, LLC, its sole General Partner, By: Brent M. Faduski, Officer, /s/ Brent M. Faduski 2018-06-20 SVLSF VI, LLC, By: Brent M. Faduski, Officer, /s/ Brent M. Faduski 2018-06-20