X0508 4 2023-09-13 0 0001770121 Sana Biotechnology, Inc. SANA 0001400240 Flagship Pioneering Inc. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 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 0001768987 Flagship VentureLabs V Manager LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001724959 Flagship VentureLabs V LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001724957 Flagship Pioneering Fund VI General Partner LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001716926 Flagship Pioneering Fund VI, 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 2023-09-13 4 J 0 2825989 D 8615337 I By Flagship VentureLabs V, LLC Common Stock 2023-09-13 4 J 0 4926378 D 8057470 I By Flagship Ventures Fund V, L.P. Common Stock 2023-09-13 4 J 0 345069 D 1035208 I By Flagship V VentureLabs Rx Fund, L.P. Common Stock 2023-09-13 4 J 0 1181745 D 0 I By Flagship Ventures Fund V General Partner LLC Common Stock 2023-09-13 4 J 0 2431281 D 7293841 I By Flagship Pioneering Fund VI, L.P. Common Stock 2023-09-13 4 J 0 70813 D 0 I By Flagship Pioneering Fund VI General Partner LLC Common Stock 581695 I See footnote On September 13, 2023, Flagship VentureLabs V LLC ("VentureLabs V") distributed in-kind to its members, pro rata and without consideration, 2,825,989 shares of the Issuer's common stock. The aforementioned distribution was made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended. Represents shares held directly by VentureLabs V. Flagship 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. On September 13, 2023, Flagship Ventures Fund V, L.P. ("Flagship Fund V") and Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx") distributed in-kind to their respective limited partners and sole general partner, Flagship Ventures Fund V General Partner, LLC ("Flagship Fund V GP"), pro rata and without consideration, 4,926,378 shares and 345,069 shares, respectively, of the Issuer's common stock. Flagship Fund V GP, in turn, distributed in-kind to its members, pro rata and without consideration, the aggregate of 1,181,745 shares it received from Flagship Fund V and Flagship Fund V Rx. The aforementioned distributions were made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended. Represents shares held directly by Flagship Fund V. Includes 2,240,555 shares received in the distribution-in-kind from VentureLabs V described in footnote (1) above. Flagship V GP is the general partner of Flagship Fund V. Dr. Afeyan 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 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. Represents shares held directly by Flagship Fund V GP. Each of the reporting persons except Flagship Fund V GP disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. On September 13, 2023, Flagship Pioneering Fund VI, L.P. ("Flagship Fund VI") distributed in-kind to its limited partners and sole general partner, Flagship Pioneering Fund VI General Partner LLC ("Flagship Fund VI GP"), pro rata and without consideration, 2,431,281 shares of the Issuer's common stock. Flagship Fund VI GP, in turn, distributed in-kind to its members, pro rata and without consideration, the 70,813 shares it received from Flagship Fund VI. The aforementioned distributions were made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended. Represents shares held directly by Flagship Fund VI. 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. Represents shares held directly by Flagship Fund VI GP. Each of the reporting persons except Flagship Fund VI GP disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any. Consists of (i) 21,641 shares held directly by Dr. Afeyan, (ii) 20,606 shares held through a trust for the benefit of Dr. Afeyan's children (the "Trust") and (iii) 539,448 shares held by VENBA Holdings LLC ("VENBA"), an estate planning entity of which Dr. Afeyan is the sole manager. Represents an aggregate of 581,695 shares received in the distributions-in-kind described in footnotes (1), (3) and (7) above. Dr. Afeyan disclaims beneficial ownership of the shares held by the Trust and VENBA except to the extent of his pecuniary interest therein, if any. Flagship Pioneering, Inc., By: /s/ Noubar B. Afeyan, Ph.D., Title: CEO 2023-09-15 Flagship Ventures Fund V General Partner LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2023-09-15 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 2023-09-15 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 2023-09-15 Flagship VentureLabs V Manager, LLC, By: Flagship Pioneering, Inc., its Manager, By: /s/ Noubar B. Afeyan. Ph.D., Title: CEO 2023-09-15 Flagship VentureLabs V LLC, By: Flagship VentureLabs V Manager, LLC, its Manager, By: Flagship Pioneering, Inc., its Manager, By: /s/ Noubar B. Afeyan. Ph.D., Title: CEO 2023-09-15 Flagship Pioneering Fund VI General Partner LLC, By: Flagship Pioneering, Inc., its Manager, By: /s/ Noubar B. Afeyan, Ph.D., Title: CEO 2023-09-15 Flagship Pioneering Fund VI, L.P., By: Flagship Pioneering Fund VI General Partner LLC, its General Partner, By: Flagship Pioneering, Inc., its Manager, By: /s/ Noubar B. Afeyan, Ph.D., Title: CEO 2023-09-15 /s/ Noubar B. Afeyan, Ph.D. 2023-09-15