Halozyme Acquires Antares Pharma for $960M

Zymeworks Acquires Theravance Biopharma

June 29, 2026

Biotechnology

Zymeworks agreed to acquire all outstanding equity of Theravance Biopharma for $17 per share in cash, representing an announced transaction value of approximately $929 million. Theravance shareholders are also entitled to a contingent value right covering 80% of net proceeds from any future monetization of ampreloxetine; Zymeworks completed the acquisition on September 23, 2026.

Halozyme Therapeutics to Acquire Elektrofi, Inc.

October 1, 2025

Biotechnology

Halozyme Therapeutics (NASDAQ: HALO) entered into a definitive agreement to acquire Elektrofi, a biopharmaceutical formulation technology company developing Hypercon, an ultra-high concentration microparticle technology for biologics. The deal includes an upfront payment of $750 million plus up to three $50 million regulatory milestone payments, and is expected to close in the fourth quarter of 2025 subject to HSR review and customary closing conditions.

Landsea Homes Acquires Antares Homes

January 9, 2024

Real Estate

Landsea Homes Corporation (Nasdaq: LSEA) has entered into a definitive agreement to acquire Antares Homes, a family-owned Dallas–Fort Worth homebuilder, for $232.2 million in cash (including repayment of anticipated debt). The acquisition expands Landsea's presence and scale in the Dallas/Fort Worth market and is expected to close in early February 2024, subject to customary closing conditions.

Merck to Acquire Harpoon Therapeutics for $680M

January 8, 2024

Biotechnology

Merck has agreed to acquire clinical-stage immunotherapy company Harpoon Therapeutics for $23.00 per share in cash, representing an approximate total equity value of $680 million. The acquisition gives Merck access to Harpoon's TriTAC / ProTriTAC platforms and lead candidate HPN328 (a DLL3-targeting T‑cell engager) to enhance its oncology pipeline; the deal is expected to close in the first half of 2024, subject to customary conditions.

Amgen Completes Acquisition of Horizon Therapeutics plc

October 6, 2023

Biotechnology

Amgen completed its acquisition of Horizon Therapeutics plc for $116.50 per share in cash, valuing the transaction equity at approximately $27.8 billion. The deal expands Amgen’s inflammation and rare-disease portfolio by adding Horizon’s first-in-class, early-in-lifecycle medicines such as TEPEZZA, KRYSTEXXA, and UPLIZNA.

Pfizer Acquires Arena Pharmaceuticals

December 13, 2021

Pharmaceuticals

Pfizer Inc. agreed to acquire clinical-stage Arena Pharmaceuticals for $100 per share in an all-cash transaction valued at approximately $6.7 billion, creating a wholly owned subsidiary. The acquisition brings Arena's development-stage portfolio — including etrasimod and cardiovascular assets — into Pfizer's Inflammation & Immunology pipeline to accelerate clinical development and expand therapeutic capabilities.