Merck completes acquisition of Harpoon Therapeutics

The Merck campus in Rahway and Linden.

Rahway-based Merck on Monday said it completed the previously announced acquisition of Harpoon Therapeutics Inc. Harpoon is now a wholly owned subsidiary of Merck, and Harpoon’s common stock will no longer be publicly traded or listed on the Nasdaq Stock Market.

Merck in January announced it agreed to pay $680 million for Harpoon and its pipeline of T-cell engagers. The deal will give Merck control of drug candidates that will expand its cancer pipeline and offer opportunities to offset the upcoming loss of Keytruda exclusivity.

Merck said the deal adds Harpoon’s HPN328, which is being evaluated in certain patients with small cell lung cancer and neuroendocrine tumors.

San Francisco-based Harpoon has developed a portfolio of novel T-cell engagers that employ the company’s proprietary Tri-specific T-cell Activating Construct, or 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.

“We continue to augment and diversify our oncology pipeline with innovative approaches to help people with cancer worldwide,” Dr. Dean Y. Li, president, Merck Research Laboratories, said. “We are pleased to welcome our Harpoon colleagues to Merck and look forward to working together to advance a novel portfolio of T-cell engagers, including MK-6070.”