Sec Form 3 Filing - Flagship Pioneering Fund VII General Partner LLC @ Sana Biotechnology, Inc. - 2024-02-12

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Flagship Pioneering Fund VII General Partner LLC 2. Issuer Name and Ticker or Trading Symbol Sana Biotechnology, Inc. [ SANA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 55 CAMBRIDGE PARKWAY, SUITE 800E 3. Date of Earliest Transaction (MM/DD/YY) 02/12/2024 (Street) CAMBRIDGE, MA02142 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Pre-Funded Warrants to purchase Common Stock $ 0.0001 02/12/2024 ( 1 ) Common Stock 2,727,272 ( 1 ) I By Flagship Pioneering Fund VII, L.P. ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Flagship Pioneering Fund VII General Partner LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE, MA02142 X Flagship Pioneering Fund VII, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE, MA02142 X Signatures Flagship Pioneering Fund VII General Partner LLC, By: Flagship Pioneering, Inc., its manager, By: /s/ Noubar B. Afeyan, PhD., Chief Executive Officer 02/14/2024 Signature of Reporting Person Date Flagship Pioneering Fund VII, L.P., By: Flagship Pioneering Fund VII General Partner LLC, its general partner, By: Flagship Pioneering, Inc., its manager, By: /s/ Noubar B. Afeyan, PhD., Chief Executive Officer 02/14/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On February 12, 2024, pursuant to an underwritten public offering by the Issuer, Flagship Pioneering Fund VII, L.P. ("Flagship Fund VII") acquired pre-funded warrants to purchase 2,727,272 shares of Common Stock (the "Pre-Funded Warrants") at a purchase price of $5.4999 per Pre-Funded Warrant. The Pre-Funded Warrants do not have an expiration date. ( 2 )Shares held by Flagship Fund VII. Flagship Pioneering Fund VII General Partner LLC ("Flagship Fund VII GP") is the general partner of Flagship Fund VII. Flagship Pioneering, Inc. ("Flagship Pioneering") is the manager of Flagship Fund VII GP. Noubar B. Afeyan, Ph.D. is the Chief Executive Officer, sole shareholder and director of Flagship Pioneering. Each of the reporting persons except Flagship Fund VII disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein, if any.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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