X0508 4 2025-12-23 0 0001029142 DYNAVAX TECHNOLOGIES CORP DVAX 0001777938 Spencer Ryan C/O DYNAVAX TECHNOLOGIES 2100 POWELL STREET, SUITE 720 EMERYVILLE CA 94608 1 1 0 0 CEO and Director 0 Common Stock 2025-12-23 4 A 0 156250 A 417455 D Common Stock 2025-12-23 4 M 0 55000 A 472455 D Common Stock 2025-12-23 4 M 0 45333 A 517788 D Common Stock 2025-12-24 4 F 0 138168 15.38 D 379620 D Restricted Stock Unit 2025-12-23 4 M 0 55000 D Common Stock 55000 55000 D Restricted Stock Unit 2025-12-23 4 M 0 45333 D Common Stock 45333 90667 D On December 23, 2025 (the "Effective Date"), in connection with the execution of an Agreement and Plan of Merger dated as of the Effective Date (the "Merger Agreement") by and among the Issuer, SANOFI, a French societe anonyme ("Parent"), and Samba Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent, the Board of Directors of the Issuer approved acceleration of vesting of certain performance-based restricted stock units ("PSUs") and restricted stock units ("RSUs") previously granted to the Reporting Person, effective as of the Effective Date. Represents PSUs previously granted to the Reporting Person that vest based on how the Issuer's total stockholder return compares to the total stockholder return of an indexed group of companies ("rTSR") over a performance period ending on December 31, 2025. Each PSU represents a contingent right to receive one share of common stock. On the Effective Date, the Board of Directors of the Issuer determined that these PSUs (which represent 125% of the target number of PSUs) were earned according to achievement of the rTSR performance condition over a shortened performance period, with the Issuer's total stockholder return determined based on the amount payable for a share of the Issuer's common stock pursuant to the Merger Agreement ($15.50), and approved such acceleration of vesting of the earned PSUs. Includes 472 shares purchased through the Issuer's Employee Stock Purchase Plan on August 15, 2025. Each RSU represents a contingent right to receive one share of the Issuer's common stock. Shares withheld by the Issuer to satisfy tax withholding requirements on vesting of PSUs and RSUs. The RSUs were granted on February 15, 2024, and were originally scheduled to vest over three years, with 1/3 vesting on each anniversary of February 15, 2024. The RSUs were granted on February 13, 2025, and were originally scheduled to vest over three years, with 1/3 vesting on each anniversary of February 13, 2025. Ryan Spencer, by /s/ Trevor Dutcher, Attorney-in-Fact 2025-12-29