Merck to Buy Harpoon Therapeutics for $680 Million

On January 8, 2024, Merck announced its plans to acquire cancer drug developer Harpoon Therapeutics, Inc. for $23.00 per share in cash for an approximate total equity value of $680 million. 

Harpoon has developed a portfolio of T-cell engagers that employ the company’s Tri-specific T-cell Activating Construct (TriTAC®) platform, an engineered protein technology designed to direct a patient’s own immune cells to kill tumor cells, and ProTriTAC™ platform, applying a prodrug concept to its TriTAC® platform to create a therapeutic T-cell engager that is designed to remain inactive until it reaches the tumor.  The acquisition includes HPN328, an investigational delta-like ligand 3 (DLL3) targeting T-cell engager being evaluated in certain patients with small cell lung cancer and neuroendocrine tumors.  Additional pipeline candidates include HPN217 targeting B-cell maturation antigen (BCMA), currently in Phase 1 clinical development for the treatment of patients with relapsed/refractory multiple myeloma, and several preclinical stage candidates, including HPN601, a conditionally activated targeting epithelial cell adhesion molecule (EpCAM) for the treatment of certain patients with EpCAM expressing tumors.

 The transaction is expected to close in the first half of 2024 and will be accounted for as an asset acquisition.