Sanofi Secures $2.2 Billion Acquisition of Dynavax Technologies

Dynavax US2681582019

The pharmaceutical landscape is set for a significant shift as Sanofi, the French drugmaking giant, has entered into a definitive agreement to acquire Dynavax Technologies Corporation. The all-cash transaction, valued at $2.2 billion, was announced last Wednesday and has been unanimously approved by Dynavax's board of directors. Shares in the biotechnology firm are now trading close to the agreed acquisition price of $15.50 per share.

This move represents a strategic expansion of Sanofi's vaccine portfolio. The acquisition provides Sanofi with access to two key Dynavax assets: the commercially available hepatitis B vaccine, HEPLISAV-B, and a promising shingles vaccine candidate known as Z-1018, which is currently undergoing Phase 1/2 clinical trials. Thomas Triomphe, Sanofi's Executive Vice President of Vaccines, highlighted that Dynavax's expertise would bolster the company's adult immunization strategy, particularly targeting a U.S. market with an estimated 100 million unvaccinated adults at risk.

For Dynavax shareholders, the $15.50 per share offer represents a substantial 39% premium over the stock's price prior to the deal's announcement. This marks a successful turnaround for Dynavax, which returned to profitability in late 2024 and reported a net income of $26.9 million for the third quarter of 2025. The company will also contribute its innovative adjuvant technology platform to Sanofi's global operations.

Financial Details and Market Reaction

Sanofi intends to finance the purchase using its existing cash reserves and stated that the transaction is not expected to impact its financial guidance for 2025. The Dynavax stock is currently trading in a narrow range just below the offer price, indicating strong market confidence that the acquisition will proceed as planned.

This deal is the latest in a series of strategic acquisitions by Sanofi this year, following its purchases of Vicebio and BluePrint Medicines. The transaction is anticipated to close in the first quarter of 2026, pending customary regulatory and antitrust approvals.

With the takeover price fixed, most analysts have issued "Hold" or "Moderate Buy" ratings on Dynavax stock. The unanimous board approval makes a competing bid for the company appear highly unlikely, directing investor focus toward the expected closure of the tender offer early next year.