---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-332264"
form_type: "8-K"
ticker: null
cik: "0001029142"
company_name: "DYNAVAX TECHNOLOGIES CORP"
filed_at: "2025-12-29T23:59:59+00:00"
generated_at: "2026-05-16T12:03:45.727606+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Sanofi to acquire Dynavax for $15.50/share in cash, total equity value ~$2.2B

## Summary
- Sanofi to acquire Dynavax for $15.50/share cash, total equity value ~$2.2B.
- Offer price represents ~39% premium to Dec 23, 2025 close and ~46% over 3-month VWAP.
- Acquisition includes marketed hepatitis B vaccine HEPLISAV-B and Phase 1/2 shingles candidate Z-1018.
- Transaction expected to close Q1 2026, subject to majority tender, HSR clearance, other conditions.
- Dynavax board unanimously approved; officers Novack and Janssen to continue roles until close.

## SEC filing metadata
- accession: 0001193125-25-332264
- form_type: 8-K
- cik: 0001029142
- company_name: DYNAVAX TECHNOLOGIES CORP
- filed_at: 2025-12-29T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 1.01, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1029142/000119312525332264/0001193125-25-332264-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1029142/000119312525332264/d82616d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-332264
- JSON: https://secwatch.observer/filing/0001193125-25-332264.json
- Plain text: https://secwatch.observer/filing/0001193125-25-332264.txt

## Key facts
- Material Agreements
  DYNAVAX TECHNOLOGIES CORP entered into Agreement and Plan of Merger with Sanofi (effective 2025-12-23).
  - Action: entry
  - Agreement: merger
  - Counterparty: Sanofi
  - Effective: 2025-12-23
  source text: On December 23, 2025, Dynavax Technologies Corporation, a Delaware corporation (the “ Company ” or “ Dynavax ”), entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) by and among the Company, Sanofi, a French soci é t é anonyme (“ Parent ”) and Samba Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“ Purchaser ”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1029142/000119312525332264/0001193125-25-332264-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.