New York – December 24, 2025 – Cooley advised Dynavax Technologies, a publicly traded vaccines company with a marketed adult hepatitis B vaccine (HEPLISAV-B), a shingles vaccine candidate and a differentiated clinical-stage pipeline, on its definitive agreement to be acquired by Sanofi for $15.50 per share in cash, representing an equity value of $2.2 billion. The acquisition strengthens Sanofi’s position in adult immunization by bringing together Dynavax’s adult hepatitis B vaccine and promising shingles asset with Sanofi’s global scale, development capabilities and commercial reach.
Lawyers Bill Roegge, Barbara Borden, Steve Przesmicki, Barbara Mirza, Austin Holt, David Burns and Jane Adams led the Cooley team advising Dynavax.
Cooley previously advised Dynavax on its successful proxy contest in June 2025, its $225 million convertible notes offering in March 2025 and its $100 million accelerated share repurchase program in November 2024.