Merck to Acquire Harpoon Therapeutics for $680M

Merck Acquires Acceleron Pharma for $11.5 Billion

September 30, 2021

Biotechnology

Merck has entered into a definitive agreement to acquire Acceleron Pharma Inc. for $180 per share in cash, representing an approximate total equity value of $11.5 billion. The acquisition brings Acceleron's late-stage sotatercept program (for pulmonary arterial hypertension) and its REBLOZYL portfolio into Merck's cardiovascular pipeline, subject to tender offer completion and customary regulatory approvals.

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.

Merck Acquires Prometheus Biosciences for $10.8 Billion

June 16, 2023

Biotechnology

Merck has agreed to acquire clinical-stage biotechnology company Prometheus Biosciences for $200.00 per share in cash, representing an approximate total equity value of $10.8 billion. The acquisition strengthens Merck's immunology pipeline by adding Prometheus' precision-medicine platform and lead candidate PRA023 (MK-7240) for inflammatory bowel disease and other immune-mediated conditions.

Johnson & Johnson Acquires Halda Therapeutics for $3.05 Billion

December 29, 2025

Biotechnology

Johnson & Johnson completed the acquisition of Halda Therapeutics OpCo, Inc. for $3.05 billion in cash, adding Halda's RIPTAC platform and clinical-stage prostate cancer candidate HLD-0915 to its oncology portfolio. The deal brings several earlier-stage RIPTAC-based programs for other solid tumors and positions J&J to advance oral targeted therapies that may overcome treatment resistance.

Amgen Completes Acquisition of Horizon Therapeutics plc

October 6, 2023

Biotechnology

Amgen completed the acquisition of Horizon Therapeutics plc for $116.50 per share in cash, valuing the transaction at approximately $27.8 billion. The deal expands Amgen's inflammation and rare-disease portfolio by adding Horizon's medicines (including TEPEZZA, KRYSTEXXA and UPLIZNA) and strengthens Amgen's biologics R&D, manufacturing and global commercial capabilities.

Gilead Sciences Acquires Immunomedics

September 13, 2020

Biotechnology

Gilead Sciences agreed to acquire Immunomedics for $88.00 per share in an all-cash transaction valuing Immunomedics at approximately $21 billion. The acquisition gives Gilead global rights (outside certain Asian territories) to Trodelvy, an FDA‑approved antibody‑drug conjugate for metastatic triple‑negative breast cancer, and accelerates Gilead’s expansion into oncology.