John L. Slebir - 23 Dec 2025 Form 4 Insider Report for DYNAVAX TECHNOLOGIES CORP (DVAX)

Role: SVP General Counsel
Signature: /s/ John L. Slebir
Issuer symbol: DVAX
Transactions as of: 23 Dec 2025
Net transactions value: -$499,881
Form type: 4
Filing time: 29 Dec 2025, 16:08:06 UTC
Previous filing: 21 Feb 2025
Next filing: 10 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Slebir John L	SVP General Counsel	C/O DYNAVAX TECHNOLOGIES, 2100 POWELL STREET, SUITE 720, EMERYVILLE	/s/ John L. Slebir	29 Dec 2025	0001475990

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	DVAX	Common Stock	Award		+33,750	+90%		71,328	23 Dec 2025	Direct	F1, F2, F3
transaction	DVAX	Common Stock	Options Exercise		+16,667	+23%		87,995	23 Dec 2025	Direct	F1, F3, F4
transaction	DVAX	Common Stock	Options Exercise		+14,141	+16%		102,136	23 Dec 2025	Direct	F1, F3, F4
transaction	DVAX	Common Stock	Tax liability	$499,881	-32,502	-32%	$15.38	69,634	24 Dec 2025	Direct	F3, F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	DVAX	Restricted Stock Unit	Options Exercise		-16,667	-50%		16,667	23 Dec 2025	Common Stock	16,667		Direct	F1, F4, F6
transaction	DVAX	Restricted Stock Unit	Options Exercise		-14,141	-33%		28,282	23 Dec 2025	Common Stock	14,141		Direct	F1, F4, F7

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	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.
F3	Includes 1,205 shares purchased through the Issuer's Employee Stock Purchase Plan on August 15, 2025.
F4	Each RSU represents a contingent right to receive one share of the Issuer's common stock.
F5	Shares withheld by the Issuer to satisfy tax withholding requirements on vesting of PSUs and RSUs.
F6	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.
F7	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.