SCHEDULE 13G/A 0001072613-22-000080 0001666306 XXXXXXXX LIVE 4 Common Stock, par value $0.0001 per share 09/30/2025 0001770121 Sana Biotechnology, Inc. 799566104 188 East Blaine Street Suite 400 Seattle WA 98102 Rule 13d-1(d) ARCH Venture Fund IX, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Fund IX Overage, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Fund X, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Fund X Overage, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Partners IX, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Partners IX Overage, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Partners X Overage, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Partners X, L.P. DE 0 45860681 0 45860681 45860681 N 17.2 PN ARCH Venture Partners IX, LLC DE 0 45860681 0 45860681 45860681 N 17.2 OO ARCH Venture Partners X, LLC DE 0 45860681 0 45860681 45860681 N 17.2 OO Keith Crandell X1 0 45860681 0 45860681 45860681 N 17.2 IN Clinton Bybee X1 0 45860681 0 45860681 45860681 N 17.2 IN Robert Nelsen X1 232444 45860681 232444 45860681 46093125 N 17.3 IN Steven Gillis X1 0 45860681 0 45860681 45860681 N 17.2 IN Kristina Burow X1 0 45860681 0 45860681 45860681 N 17.2 IN Sana Biotechnology, Inc. 188 East Blaine Street, Suite 400, Seattle, WA 98102 ARCH Venture Fund IX, L.P. ("AVF IX"); ARCH Venture Partners IX, L.P. ("AVP IX LP"); ARCH Venture Partners IX, LLC ("AVP IX LLC"); ARCH Venture Fund IX Overage, L.P. ("AVF IX Overage"); ARCH Venture Partners IX Overage, L.P. ("AVP IX Overage GP"); ARCH Venture Fund X, L.P. ("AVF X"); ARCH Venture Partners X, L.P. ("AVP X LP"); ARCH Venture Fund X Overage, L.P. ("AVF X Overage"); ARCH Venture Partners X Overage, L.P. ("AVP X Overage GP"); ARCH Venture Partners X, LLC ("AVP X LLC"); (collectively, the "Reporting Entities" and individually, each a "Reporting Entity"); and Keith Crandell ("Crandell"), Robert Nelsen ("Nelsen") and Clinton Bybee ("Bybee") (collectively, the "Managing Directors" and individually, each a "Managing Director"), and Steven Gillis ("Gillis") and Kristina Burow ("Burow"), along with Nelsen and Crandell, collectively the "Investment Committee"; individually "Committee members". The Reporting Entities, Managing Directors and the Investment Committee members collectively are referred to as the "Reporting Persons". 8755 W. Higgins Avenue, Suite 1025, Chicago, IL 60631 Each of AVF IX, AVP IX LP, AVF IX Overage, AVP IX Overage GP, AVF X, AVP X LP, AVF X Overage and AVP X Overage GP are limited partnerships organized under the laws of the State of Delaware. AVP IX LLC and AVP X LLC are each a limited liability company organized under the laws of the State of Delaware. Each Managing Director and Committee Member is a US citizen. Y AVF IX is the record owner of 10,667,387 shares of Common Stock (the "AVF IX Shares") as of September 30, 2025. AVP IX LP, as the sole general partner of AVF IX, may be deemed to beneficially own the AVF IX Shares. AVF IX Overage is the record owner of 10,301,250 shares of Common Stock (the "AVF IX Overage Shares") as of September 30, 2025. AVP IX Overage GP, as the sole general partner of AVF IX Overage, may be deemed to beneficially own the AVF IX Overage shares, combined with AVF IX Shares (the "IX Record Shares"). AVF X is the record owner of 12,446,022 shares of Common Stock (the "AVF X Shares") as of September 30, 2025. AVP X LP, as the sole general partner of AVF X, may be deemed to beneficially own the AVF X Shares. AVF X Overage is the record owner of 12,446,022 shares of Common Stock (the "AVF X Overage Shares") as of September 30, 2025. AVP X Overage GP, as the sole general partner of AVF X Overage, may be deemed to beneficially own the AVF X Overage Shares, combined with AVF X Shares (the "X Record Shares"). AVP IX LLC, as the sole general partner of AVP IX LP and AVP IX Overage GP, may be deemed to beneficially own the IX Record Shares. As managing directors of AVP IX LLC, each Managing Director may also be deemed to share the power to direct the disposition and vote of the IX Record Shares. AVP X LLC, as the sole general partner of AVP X LP and AVP X Overage GP, may be deemed to beneficially own the X Record Shares. As Investment Committee Members of AVP X LLC, each Committee Member may also be deemed to share the power to direct the disposition and vote of the X Record Shares. In addition, as of September 30, 2025, Nelsen is a holder of vested options to purchase 218,591 shares of Common Stock (the "Vested Option Shares") and 1,353 fully vested restricted stock units ("RSUs") and Enzo Family Trust of 2015, the beneficiaries of which are members of Nelsen's family, holds 12,500 shares of common stock. Each Reporting Person disclaims beneficial ownership of such shares of Common Stock except for the shares, if any, such Reporting Person holds of record. The information required by Item 4(b) is incorporated by reference to Row 11 of the cover pages hereto. The percentages set forth on the cover page for each Reporting Person (other than Nelsen) is based upon 266,366,120 shares of common stock outstanding as of October 29, 2025, as reported on the Issuer's Form 10-Q as filed with the Securities and Exchange Commission on November 6, 2025, and, in the case of Nelsen, assumes the exercise of the Vested Option Shares. See row 11 of the cover pages. See row 5 of the cover pages. See row 6 of the cover pages. See row 7 of the cover pages. See row 8 of the cover pages. Y Y Y Y Y Y ARCH Venture Fund IX, L.P. /s/ ARCH Venture Partners IX, L.P. 11/14/2025 /s/ Mark McDonnell* 11/14/2025 ARCH Venture Fund IX Overage, L.P. /s/ ARCH Venture Partners IX Overage, L.P. 11/14/2025 /s/ ARCH Venture Partners IX, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Fund X, L.P. /s/ ARCH Venture Partners X, L.P. 11/14/2025 /s/ ARCH Venture Partners X, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Fund X Overage, L.P. /s/ ARCH Venture Partners X Overage, L.P. 11/14/2025 /s/ ARCH Venture Partners X, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners IX, L.P. /s/ ARCH Venture Partners IX, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners IX Overage, L.P. /s/ ARCH Venture Partners IX, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners X Overage, L.P. /s/ ARCH Venture Partners X, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 /s/ Mark McDonnell 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners X, L.P. /s/ ARCH Venture Partners X, LLC 11/14/2025 /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners IX, LLC /s/ Mark McDonnell 11/14/2025 ARCH Venture Partners X, LLC /s/ Mark McDonnell 11/14/2025 Keith Crandell /s/ Mark McDonnell 11/14/2025 Clinton Bybee /s/ Mark McDonnell 11/14/2025 Robert Nelsen /s/ Mark McDonnell 11/14/2025 Steven Gillis /s/ Mark McDonnell 11/14/2025 Kristina Burow /s/ Mark McDonnell 11/14/2025 * This Schedule 13G was executed by Mark McDonnell pursuant to Powers of Attorney filed as Exhibit 24.0 and Exhibit 24.1 to the Form 3 relating to the beneficial ownership of shares of Sana Biotechnology, Inc. by certain of the Reporting Persons filed with the Securities and Exchange Commission on February 3, 2021 and incorporated herein in its entirety by reference and Powers of Attorney filed as Exhibit 24 to the Form 3 relating to the beneficial ownership of shares of Gossamer Bio, Inc. by certain of the Reporting Persons filed with the Securities and Exchange Commission on February 7, 2019 and incorporated herein in its entirety by reference.