Why Is Cancer Focused Harpoon Therapeutics Stock Shooting Higher Today?

Merck & Co Inc MRK is reportedly negotiating to purchase cancer drugmaker Harpoon Therapeutics Inc HARP for an estimated $700 million. 

The move comes as Merck endeavors to diversify its revenue sources, anticipating potential pricing challenges for its flagship drug, Keytruda, an acclaimed cancer immunotherapy that amassed a staggering $20.9 billion in sales in 2022, securing its position as one of the world's top-selling medications.

The proposed acquisition aims to fortify Merck's dominance in the oncology sector, Bloomberg noted. 

Discussions suggest that Merck is contemplating a price of approximately $23 per share for Harpoon.

Harpoon's focus includes developing drugs targeting specific cancers like lung cancer and multiple myeloma. 

The lead candidate targets delta-like ligand 3, which is highly expressed in small-cell lung cancer and neuroendocrine tumors.

Harpoon's primary candidate is undergoing early-stage trials independently and with existing immunotherapy for small-cell lung cancer patients.

In October, Harpoon announced updated data from the Phase 1/2 clinical trial evaluating HPN328 in small-cell lung cancer.

The company said HPN328, designed to recruit a patient's immune cells to kill tumors, was generally well tolerated across all cohorts in the study and showed a confirmed response rate of 35% across all tumor types, including three confirmed completed responses. 

In its strategic pursuit of enhancing its product pipeline, Merck has actively sought external drug candidates. 

This move follows previous agreements, including the acquisition of rights to sell Daiichi Sankyo Co.'s three experimental cancer drugs, involving a substantial upfront payment of $4 billion and potential future payments of up to $22 billion. 

In April, Merck finalized a $10.8 billion deal for Prometheus, a manufacturer of autoimmune drugs.

Price Action: MRK closed at $117.20 on Friday. HARP shares are up 99.8% at $21.08 during the premarket session on the last check Monday.