Dynavax surges after Sanofi agrees to $2.2 bn buyout

Dynavax Technologies shares surged nearly 38% premarket after Sanofi agreed to acquire the vaccine maker for $15.50 per share, valuing the deal at about $2.2 billion. The offer represents a roughly 40% premium and adds Dynavax HEPLISAV-B vaccine to Sanofi portfolio. The deal is expected to close in Q1 2026.