Sanofi and Dynavax Technologies Corporation
Type: Acquisition
Buyer: Sanofi
Seller: Dynavax Technologies Corporation
Focus: HEPLISAV-B and Z-1018
Deal value: $2.2 billion
Financial impact: The deal provides Sanofi with a marketed adult hepatitis B vaccine and a promising shingles candidate, strengthening its expansion beyond flu-focused products and enabling faster, larger-scale progress in adult vaccines to meet critical public health needs.
Sanofi has completed its $2.2 billion acquisition of Dynavax Technologies, gaining the marketed adult hepatitis B vaccine HEPLISAV-B, distinguished by its two-dose, one-month regimen, and the shingles vaccine candidate Z-1018, currently in Phase 1/2 trials, along with other pipeline assets. This deal strengthens Sanofi’s adult immunisation portfolio, expanding beyond its traditional flu-focused offerings and addressing major public health gaps, including hepatitis B infections and shingles, which affect millions each year. By combining Dynavax’s innovative vaccines with Sanofi’s global scale, commercial reach, and development capabilities, the company aims to accelerate access to and growth of adult vaccines. Thomas Triomphe, Sanofi’s EVP of Vaccines, highlighted that Dynavax complements Sanofi’s expertise, while Dynavax CEO Ryan Spencer emphasised that joining Sanofi provides the scale to maximise the vaccine portfolio’s impact. The transaction closed following a tender offer at $15.50 per share on February 9, 2026.
HEPLISAV-B
HEPLISAV-B (Adjuvanted Hepatitis B Vaccine, V270), developed by Dynavax Technologies (a Sanofi subsidiary), is a two-dose intramuscular vaccine for adults (18+) and patients with renal disease, administered one month apart. It combines recombinant hepatitis B surface antigen with the CpG 1018 adjuvant, a synthetic DNA sequence that targets TLR-9 to enhance immune response. Launched in the US, Germany, Poland, and Hungary, and approved across the EU, UK, Iceland, Liechtenstein, and Norway, HEPLISAV-B provides faster, stronger, and more durable protection than traditional three-dose vaccines, including for immunocompromised or previously non-responsive individuals.
Z-1018
Adjuvanted varicella zoster vaccine (Z-1018), developed by Dynavax Technologies (a Sanofi subsidiary), is a recombinant vaccine designed to prevent infections from the varicella zoster virus (VZV). It combines the recombinant glycoprotein E (VZVgE) antigen with Dynavax’s CpG 1018 adjuvant, a synthetic TLR-9–targeting DNA sequence that enhances immune response. Currently in Phase 1/2 clinical trials in the US and Australia, Z-1018 is part of Dynavax’s broader vaccine pipeline, including additional investigational candidates.
Eleven years' market revenue of Sanofi
Sanofi has shown a steady increase in revenue over the past 11 years, reaching its highest level in 2025 with €43.62 billion in total sales. This growth was driven largely by strong performances from key products, led by Dupixent, which generated €15.7 billion in net sales and accounted for about 36 % of total revenue, along with solid contributions from rare disease therapies such as Altuviiio (€1.16 billion) and Fabrazyme (€1.02 billion), as well as established treatments like Lantus (€1.73 billion), Nexviazyme/Nexviadyme (€0.79 billion) and Alprolix (€0.60 billion); vaccines and other medicines also supported the overall revenue increase in 2025.
Eleven years of market revenue of Sanofi (2015-2025)
Fig 12: Market revenue of Sanofi
Market Impact of This Partnership
The acquisition of Sanofi’s purchase of Dynavax Technologies for approximately $2.2 billion (about €1.9 billion) has had a clear market impact, signalling strong investor and industry confidence in Sanofi’s strategic pivot toward adult immunisation. The all‑cash deal, valued at $15.50 per share, represented roughly a 39 % premium over Dynavax’s pre‑announcement share price, triggering a near 40 % surge in Dynavax stock on the news as markets reacted to the value of its hepatitis B vaccine HEPLISAV‑B and the potential of its shingles candidate Z‑1018.
“Sanofi’s $2.2 billion acquisition of Dynavax strengthens its adult vaccine portfolio, adding immediate revenue and long-term growth potential.”
For Sanofi, the acquisition strengthens its vaccine portfolio and positions it more competitively in the growing adult vaccine market by adding a marketed vaccine with recurring revenue and early‑stage pipeline assets with significant long‑term potential. Analysts noted that the deal is expected to have minimal near‑term impact on Sanofi’s 2025 financial outlook while offering strategic upside over time through expanded commercial reach and R&D synergies in adult immunisation.
Overall, the transaction reflects broader M&A trends in pharmaceuticals and biotech—where firms with near‑commercial assets command premium valuations—and is likely to influence consolidation activity in vaccine and specialty medicine sectors as competitors respond to heightened competition in adult immunisation markets.