Sanofi Completes Acquisition of Dynavax in $2.2 Billion Deal

The pharmaceutical giant Sanofi has finalized its acquisition of Dynavax Technologies, concluding a transaction valued at approximately $2.2 billion. As a result, Dynavax will be delisted from public markets, ending its run as an independent entity. This move provides Sanofi with key strategic assets in the vaccine sector.

Sanofi successfully completed the takeover through a tender offer that expired last Monday. Regulatory filings with the U.S. Securities and Exchange Commission (SEC) indicate that roughly 73.92% of Dynavax's outstanding shares were validly tendered. This substantial majority allowed Sanofi to execute a "short-form" merger under Delaware law immediately, bypassing the need for further shareholder approval.

Consequently, trading of Dynavax shares on the NASDAQ Global Select Market was halted on Tuesday morning. For investors who did not tender their shares during the offer period, the outcome is effectively the same: their holdings will be automatically converted into the right to receive a cash payment of $15.50 per share.

Should investors sell immediately? Or is it worth buying Dynavax?

• Cash Consideration: $15.50 per share
• Total Deal Value: Around $2.2 billion
• Market Status: Delisting from NASDAQ is effective
• Key Assets Acquired: HEPLISAV-B vaccine and Z-1018 candidate

Strategic Rationale and Acquired Portfolio

This acquisition significantly bolsters Sanofi's position in the adult vaccine market. The deal centers on two primary assets. The first is HEPLISAV-B, an already-approved hepatitis B vaccine. Its competitive advantage lies in a two-dose regimen administered within one month, offering a more convenient schedule compared to traditional three-dose vaccines.

The second asset is the investigational candidate Z-1018, currently in Phase 1/2 clinical development for the prevention of shingles. Securing this pipeline product underscores Sanofi's strategic commitment to expanding its portfolio of adult immunizations.

With the merger now complete, Dynavax's reporting obligations to the SEC have been terminated. The company's outstanding convertible notes for 2026 and 2030 have been adjusted to reflect the right to receive the cash consideration from the merger. As the integration process into Sanofi begins, Dynavax shareholders will receive the agreed-upon cash payout, marking the end of the company's independent era.