This Amendment No. 3 (this “Amendment”) to
Schedule 14D-9 amends and supplements the Schedule 14D-9 previously filed by Dynavax Technologies Corporation, a Delaware corporation (the
“Company”), with the Securities and Exchange Commission (the “SEC”) on January 12, 2026 (as amended or supplemented from time to time, the “Schedule 14D-9”), with
respect tender offer by Samba Merger Sub, Inc., a Delaware corporation (“Purchaser”) and an indirect wholly owned subsidiary of Sanofi, a French société anonyme (“Parent”), to purchase any and all of the issued
and outstanding Shares of the Company for $15.50 per Share in cash, without interest, subject to any applicable withholding taxes, upon the terms and subject to the conditions set forth in that certain Offer to Purchase dated January 12,
2026 (together with any amendments or supplements thereto, the “Offer to Purchase”), and in the related Letter of Transmittal (together with any amendments or supplements thereto, the “Letter of Transmittal,” which, together
with the Offer to Purchase, constitutes the “Offer”). The Offer is described in a Tender Offer Statement on Schedule TO (as amended or supplemented from time to time, the “Schedule TO”) filed by Parent and Purchaser with the
SEC on January 12, 2026. The Offer to Purchase and the Letter of Transmittal have been filed as Exhibits (a)(1)(A) and (a)(1)(B) to the Schedule 14D-9, respectively, and are incorporated therein by
reference.
This Amendment is being filed to reflect certain amendments and updates to Item 4 of the
Schedule 14D-9 as reflected below, which should be read in conjunction with the Schedule 14D-9. In addition, nothing in the update to the disclosure in Item 4
of the Schedule 14D-9 shall be deemed an admission of the legal necessity or materiality under applicable laws of any such disclosure set forth herein.
Capitalized terms used in this Amendment but not defined herein shall have the respective meaning given to such terms in the Schedule 14D-9. Except to the extent specifically amended or supplemented as provided in this Amendment, the information set forth in the
Schedule 14D-9 remains unchanged.
Item 4. The Solicitation or Recommendation.
Item 4 of the Schedule 14D-9 is hereby corrected for a prior error as follows:
By replacing the number struck through in the fifth sentence of the fourth full paragraph on page 47 under the section entitled “Item
4. The Solicitation or Recommendation — (e) Opinions of the Financial Advisors to the Board- Opinion of Goldman Sachs & Co. LLC- General” with the new number:
“During the two-year period ended December 23, 2025, Goldman Sachs has recognized
compensation for financial advisory and/or underwriting services provided by Goldman Sachs Investment Banking to the Company and/or its affiliates of approximately $11 $6 million.”
