Day One Biopharmaceuticals Acquires Mersana Therapeutics

Biogen Acquires RayThera for Up to $1 Billion to Expand Immunology Pipeline

June 18, 2026

Healthcare Services

Biogen entered into a definitive agreement to acquire RayThera, a private immunology-focused biotechnology company, for total consideration of up to $1 billion driven by an upfront payment plus clinical and regulatory milestone payments. The deal is expected to close in the third quarter of 2026, with Biogen taking over development, manufacturing, and global commercialization of RayThera’s small-molecule anti-inflammatory assets.

Servier Acquires Day One Biopharmaceuticals to Expand Rare Oncology Portfolio

March 6, 2026

Pharmaceuticals

Servier and Day One Biopharmaceuticals entered into a definitive agreement for Servier to acquire Day One for $21.50 per share in cash, valuing the deal at approximately $2.5 billion. The acquisition is expected to close in the second quarter of 2026 and is intended to strengthen Servier’s rare oncology and pediatric low-grade glioma positioning while expanding its clinical-stage pipeline.

Merck & Co. (Merck Sharp & Dohme) Acquires Cidara Therapeutics

January 8, 2026

Biotechnology

Merck Sharp & Dohme LLC (Merck & Co., Inc.) completed its cash tender offer and follow-on merger to acquire Cidara Therapeutics, Inc. for $221.50 per share, valuing the deal at about $9.2 billion. The acquisition adds Cidara’s late-stage, long-acting, strain-agnostic influenza antiviral candidate CD388 to Merck’s respiratory pipeline.

Genmab A/S Acquires Merus N.V. via Tender Offer

December 12, 2025

Biotechnology

Genmab A/S, through its wholly owned purchaser Genmab Holding II B.V., completed a tender offer to acquire outstanding common shares of Merus N.V. for $97.00 per share and commenced a subsequent offering period. The acquisition adds Merus' lead late‑stage oncology asset petosemtamab to Genmab's portfolio, expanding its antibody therapeutics pipeline and expected to be accretive to EBITDA by 2029.

Pharmacosmos Acquires G1 Therapeutics

August 7, 2024

Biotechnology

Pharmacosmos A/S, through its U.S. affiliate Pharmacosmos Therapeutics Inc., agreed to acquire all outstanding shares of G1 Therapeutics, Inc. for $7.15 per share in cash, implying an approximate equity value of $405 million. The deal brings G1's FDA-approved oncology product COSELA into Pharmacosmos' commercial portfolio to accelerate patient access and expand Pharmacosmos' presence in oncology and supportive care.

Merck Acquires Pandion Therapeutics

February 25, 2021

Biotechnology

Merck will acquire Pandion Therapeutics for $60 per share in cash, representing an approximate total equity value of $1.85 billion, via a tender offer and subsequent merger. Pandion is a clinical-stage biotechnology company focused on precision immune modulators (TALON platform) with lead candidate PT101 targeting regulatory T cells for autoimmune diseases; the transaction is expected to close in the first half of 2021 subject to customary conditions.