Sec Form 4 Filing - Katabi Maha @ RayzeBio, Inc. - 2024-02-26

FORM 4 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 Katabi Maha 2. Issuer Name and Ticker or Trading Symbol RayzeBio, Inc. [ RYZB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O RAYZEBIO, INC., 5505 MOREHOUSE DR, SUITE 300 3. Date of Earliest Transaction (MM/DD/YY) 02/26/2024 (Street) SAN DIEGO, CA92121 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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 Common Stock 02/26/2024 D( 1 ) 1,209,764 D $ 62.5 0 I See footnote ( 2 ) Common Stock 02/26/2024 D( 1 ) 1,209,764 D $ 62.5 0 I See footnote ( 3 )

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 Stock Option (right to buy) $ 22.72 02/26/2024 D 18,235 ( 4 ) 11/16/2033 Common Stock 18,235 ( 4 ) 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Katabi Maha C/O RAYZEBIO, INC. 5505 MOREHOUSE DR, SUITE 300 SAN DIEGO, CA92121 X Signatures /s/ Jeff Woodley, Attorney-in-Fact 02/27/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated December 25, 2023, by and among RayzeBio, Inc. (the "Issuer"), Bristol-Myers Squibb Company ("BMS") and, by way of a joinder dated December 26, 2023, Rudolph Merger Sub Inc., a wholly owned subsidiary of BMS ("Purchaser"), on February 22, 2024, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a "Share") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of BMS (the "Merger"). Pursuant to the terms of the Merger Agreement, the Shares were tendered and disposed of at the Offer Acceptance Time (as defined in the Merger Agreement) in exchange for the right to receive the $62.50 per Share in cash, without interest, subject to any applicable withholding of taxes (the "Cash Amount"). At the effective time of the Merger, each issued and outstanding Share was cancelled in exchange for the Cash Amount. ( 2 )The shares are held by Sofinnova Venture Partners X, L.P. ("SVP X"). Sofinnova Management X, L.P. ("SM X LP"), the general partner of SVP X, may be deemed to have sole voting and dispositive power over these shares, and Sofinnova Management X-A, L.L.C. ("SM X LLC"), the general partner of SM X LP, may be deemed to have sole voting and dispositive power over these shares. Dr. James I. Healy and Dr. Maha Katabi, the managing members of SM X LLC, may be deemed to have shared power to vote and dispose of these shares. Such entities and individuals disclaim beneficial ownership of such shares except to the extent of their pecuniary interest therein. ( 3 )The shares are held by Sofinnova Venture Partners XI, L.P. ("SVP XI"). Sofinnova Management XI, L.P. ("SM XI LP"), the general partner of SVP XI, may be deemed to have sole voting and dispositive power over these shares, and Sofinnova Management XI, L.L.C. ("SM XI LLC"), the general partner of SM XI LP, may be deemed to have sole voting and dispositive power over these shares. Dr. James I. Healy and Dr. Maha Katabi, the managing members of SM XI LLC, may be deemed to have shared power to vote and dispose of these shares. Such entities and individuals disclaim beneficial ownership of such shares except to the extent of their pecuniary interest therein. ( 4 )At the effective time of the Merger, pursuant to the Merger Agreement, each outstanding option was accelerated and became fully vested and exercisable and was cancelled and automatically converted into the right to receive cash, without interest, in an amount equal to the product of (i) the total number of Shares subject to such option multiplied by (ii) the excess of (x) $62.50 per Share over (y) the exercise price payable per Share under such option, which amount will be subject to any withholding taxes.

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