X0407 4 2023-06-06 0 0001770121 Sana Biotechnology, Inc. SANA 0001724575 Flagship Ventures Fund V General Partner LLC 55 CAMBRIDGE PARKWAY SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001627639 Flagship Ventures Fund V, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001724939 Flagship V VentureLabs Rx Fund, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001222012 AFEYAN NOUBAR 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0 Common Stock 2023-06-06 4 S 0 181461 6.3061 D 10920533 I By Flagship Ventures Fund V, L.P. Common Stock 2023-06-06 4 S 0 22297 6.3061 D 1403037 I By Flagship V VentureLabs Rx Fund, L.P. Common Stock 2023-06-07 4 S 0 177240 6.2397 D 10743293 I By Flagship Ventures Fund V, L.P. Common Stock 2023-06-07 4 S 0 22760 6.2397 D 1380277 I By Flagship V VentureLabs Rx Fund, L.P. Common Stock 11441326 I By Flagship VentureLabs V, LLC Common Stock 9725122 I By Flagship Pioneering Fund VI, L.P. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.30 to $6.415, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. Represents shares held directly by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship V GP. Each of the reporting persons except Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. Represents shares held directly by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Each of the reporting persons except Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.20 to $6.36, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. Represents shares held directly by Flagship VentureLabs V LLC. ("VentureLabs V"). VentureLabs V Manager LLC ("VentureLabs V Manager") is the manager of VentureLabs V. Flagship Pioneering, Inc. ("Flagship Pioneering") is the manager of VentureLabs V Manager. Dr. Afeyan is the CEO and sole stockholder of Flagship Pioneering. Each of the reporting persons except VentureLabs V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. Represents shares held directly by Flagship Pioneering Fund VI, L.P. ("Flagship Fund VI"). Flagship Pioneering Fund VI General Partner LLC ("Flagship Fund VI GP") is the general partner of Flagship Fund VI. Flagship Pioneering is the manager of Flagship Fund VI GP. Each of the reporting persons except Flagship Fund VI disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. Flagship Ventures Fund V General Partner LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2023-06-08 Flagship Ventures Fund V, L.P., By: Flagship Ventures Fund V General Partner LLC, its General Partner, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2023-06-08 Flagship V VentureLabs Rx Fund, L.P., By: Flagship Ventures Fund V General Partner LLC, its General Partner, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2023-06-08 /s/ Noubar B. Afeyan, Ph.D. 2023-06-08