Sec Form 4 Filing - Sun Elaine D @ DYNAVAX TECHNOLOGIES CORP - 2026-02-10

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 Sun Elaine D 2. Issuer Name and Ticker or Trading Symbol DYNAVAX TECHNOLOGIES CORP [ DVAX] 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 DYNAVAX TECHNOLOGIES, 2100 POWELL STREET, SUITE 720 3. Date of Earliest Transaction (MM/DD/YY) 02/10/2026 (Street) EMERYVILLE, CA94608 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 - Restricted Stock Units 02/10/2026 D( 1 )( 2 ) 29,865 D 0 D

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) $ 13.33 02/10/2026 D( 1 )( 2 ) 45,000 ( 4 ) ( 4 ) Common Stock 45,000 ( 4 ) 0 D Stock Option (Right to Buy) $ 11.68 02/10/2026 D( 1 )( 2 ) 11,250 ( 4 ) ( 4 ) Common Stock 11,250 ( 4 ) 0 D Stock Option (Right to Buy) $ 11.2 02/10/2026 D( 1 )( 2 ) 22,500 ( 4 ) ( 4 ) Common Stock 22,500 ( 4 ) 0 D Stock Option (Right to Buy) $ 11.85 02/10/2026 D( 1 )( 2 ) 22,500 ( 4 ) ( 4 ) Common Stock 22,500 ( 4 ) 0 D Stock Option (Right to Buy) $ 10.18 02/10/2026 D( 1 )( 2 ) 28,500 ( 4 ) ( 4 ) Common Stock 28,500 ( 4 ) 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Sun Elaine D C/O DYNAVAX TECHNOLOGIES 2100 POWELL STREET, SUITE 720 EMERYVILLE, CA94608 X Signatures Francis Cano, by /s/ Trevor Dutcher, Attorney-in-Fact 02/10/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )This Form 4 reports securities transacted pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, SANOFI, a French societe anonyme ("Parent"), and Samba Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent ("Purchaser"). ( 2 )Pursuant to the Merger Agreement, Purchaser completed a tender offer to acquire all of the issued and outstanding shares of common stock of the Issuer, par value $0.001 per share (the "Common Stock"), for $15.50 per share (the "Offer Price"), in cash, without interest and subject to any applicable withholding of taxes. On February 10, 2026, Purchaser merged with and into the Issuer, with the Issuer surviving as an indirect wholly owned subsidiary of Parent (the effective time of such merger, the "Effective Time"). ( 3 )Pursuant to the terms of the Merger Agreement, at the Effective Time, each restricted stock unit ("RSU") award that was outstanding as of immediately prior to the Effective Time held by the Reporting Person, whether vested or unvested, was cancelled and converted into the right to receive cash in an amount equal to (i) the number of shares issuable in settlement of such RSU award immediately prior to the Effective Time without regard to vesting, multiplied by (ii) the Offer Price. ( 4 )Pursuant to the terms of the Merger Agreement, (i) each stock option that was outstanding as of immediately prior to the Effective Time held by the Reporting Person became fully vested immediately prior to the Effective Time, and (ii) at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time was cancelled and converted into the right to receive cash in an amount equal to (i) the number of shares subject to such stock option immediately prior to the Effective Time, without regard to vesting, multiplied by (ii) the excess of the Offer Price over the exercise price per share of such stock option.

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).

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