(Updates with the latest Dynavax stock movement in the last paragraph.)

Sanofi (SNY) said Wednesday it has agreed to buy Dynavax Technologies (DVAX) in a cash tender offer valued at about $2.2 billion.

Under the terms of the deal, Dynavax shareholders will receive $15.50 a share in cash, and any shares not tendered would be converted to the same cash amount if the offer closes, the company said.

The deal adds Dynavax's marketed adult hepatitis B vaccine Heplisav B and its phase 1-2 shingles candidate Z 1018, Sanofi said.

The transaction was approved by Dynavax's board and is expected to close in Q1 2026, subject to tender, antitrust, and customary closing conditions, it said.

Sanofi also said it plans to pay with available cash and added that one of its fully owned units will later merge with Dynavax.

Shares of Dynavax were up by over 38% in recent Wednesday trading.

Price: 48.40, Change: +0.08, Percent Change: +0.17