French pharma giant Sanofi has agreed to acquire US based Dynavax Technologies for approximately $2.2 billion in cash, adding the marketed adult hepatitis B vaccine HEPLISAV-B and an early stage shingles vaccine candidate (Z-1018) to its portfolio. The deal enhances Sanofi’s adult immunization focus, leveraging its global infrastructure to expand these assets.
Glimpse:
Announced on December 24, 2025, Sanofi will pay $15.50 per share a 39% premium over Dynavax’s prior closing price via a tender offer, with closure expected in Q1 2026. HEPLISAV-B’s innovative two dose regimen offers faster protection than traditional three dose hepatitis B vaccines, while Z-1018 targets the multi billion dollar shingles market dominated by GSK’s Shingrix. Funded by cash reserves, the acquisition supports Sanofi’s strategy to diversify beyond Dupixent ahead of its 2031 patent cliff.
Sanofi has entered into a definitive agreement to acquire Dynavax Technologies Corporation in an all cash transaction valued at around $2.2 billion, marking a strategic push to strengthen its adult vaccine franchise. The deal, unveiled on December 24, 2025, sees Sanofi offering $15.50 per share for all outstanding Dynavax shares through a tender offer, representing a 39% premium to the December 23 closing price.
Dynavax brings immediate revenue from HEPLISAV-B, a differentiated adult hepatitis B vaccine already marketed in the US. Its two dose schedule (over one month) provides high seroprotection rates faster than competitors’ three-dose, six-month regimens driving strong uptake in retail pharmacies and addressing unmet needs in adult immunization.
The acquisition also includes Z-1018, Dynavax’s shingles (herpes zoster) vaccine candidate in Phase 1/2 development, along with additional early stage pipeline projects and the CpG 1018 adjuvant technology. Analysts view Z-1018 as a potential “Shingrix challenger,” with early data suggesting comparable efficacy but better tolerability (fewer flu like side effects), positioning it to capture share in a market where GSK’s Shingrix generates billions annually.
This move integrates Dynavax’s innovative assets with Sanofi’s global manufacturing, regulatory expertise, and commercial reach, accelerating potential international launches of HEPLISAV-B (currently US only) and advancing the shingles program. It fills key gaps in Sanofi’s portfolio, which lacks dedicated adult hepatitis B or shingles offerings.
The transaction is funded with available cash and won’t impact Sanofi’s 2025 financial guidance. Subject to customary conditions including antitrust clearances the deal is slated to close in the first quarter of 2026.
This acquisition continues Sanofi’s 2025 M&A momentum, following deals for Vicebio ($1.5 billion) and Blueprint Medicines (up to $9.5 billion), as it builds resilience ahead of Dupixent’s looming patent expiry.
“Dynavax enhances Sanofi’s adult immunization presence by adding differentiated vaccines that complement Sanofi’s expertise.”
By
HB Team
