Servier Acquires Day One Biopharmaceuticals for About $2.5 Billion

Day One Biopharmaceuticals Acquires Mersana Therapeutics

January 6, 2026

Biotechnology

Day One Biopharmaceuticals (Nasdaq: DAWN) completed its acquisition of Mersana Therapeutics (Nasdaq: MRSN) via a tender offer, purchasing all outstanding shares for $25 per share in cash plus one non-tradable contingent value right (CVR) per share for up to $30.25 in milestone payments (total consideration up to $55.25 per share). The deal adds Mersana’s clinical-stage ADC emiltatug ledadotin (Emi-Le) targeting adenoid cystic carcinoma (ACC) to Day One’s pipeline; Mersana will become a wholly owned subsidiary and its shares will be delisted from Nasdaq.

Sanofi to Acquire Provention Bio for $2.9 Billion

March 13, 2023

Pharmaceuticals

Sanofi has entered into an agreement to acquire Provention Bio for $25.00 per share in cash, valuing the deal at approximately $2.9 billion. The transaction will be implemented via a cash tender offer followed by a merger, with completion expected in the second quarter of 2023 subject to customary closing conditions.

Sanofi to Acquire DR-0201 Program from Dren Bio

March 20, 2025

Biotechnology

Sanofi has agreed to acquire DR-0201, a CD20-directed bispecific myeloid cell engager, through purchase of Dren Bio’s affiliate Dren-0201 for an upfront $600 million and up to $1.3 billion in milestone payments. The deal, aimed at broadening Sanofi’s immunology pipeline and advancing deep B-cell depletion approaches, is expected to close in Q2 2025 subject to regulatory approvals; Dren Bio will continue to operate independently to advance its broader pipeline.

Sanofi to Acquire Vicebio for Up to $1.6 Billion

July 25, 2025

Healthcare Services

Sanofi has entered an exclusive, definitive agreement to acquire biopharmaceutical company Vicebio for up to US$1.6 billion, comprising a US$1.15 billion upfront payment plus up to US$450 million in development and regulatory milestones. The deal is aimed at accelerating Vicebio’s next-generation respiratory virus vaccine platform, including lead candidate VXB-241 targeting RSV and hMPV.

Biogen Acquires Reata Pharmaceuticals

July 28, 2023

Biotechnology

Biogen Inc. agreed to acquire Reata Pharmaceuticals, Inc. for $172.50 per share in cash, representing an enterprise value of approximately $7.3 billion. The acquisition adds Reata's FDA-approved SKYCLARYS (omaveloxolone) for Friedreich's ataxia to Biogen's rare disease portfolio and is expected to be significantly accretive to Biogen's Non-GAAP diluted EPS beginning in 2025; the transaction was anticipated to close in Q4 2023.

Sanofi to Acquire Blueprint Medicines to Expand Rare Immunology Pipeline

June 2, 2025

Pharmaceuticals

Sanofi and Blueprint Medicines entered into an agreement under which Sanofi will acquire Blueprint via a cash tender offer and subsequent merger. The deal values Blueprint at $129.00 per share in cash (approximately $9.1 billion equity value), with additional potential milestone payments tied to BLU-808 via a contingent value right.