Merck Reuters) -Merck & Co said on Monday it would buy cancer drug developer Harpoon Therapeutics for about $680 million, reinforcing its oncology portfolio with immunotherapies.
The U.S. drugmaker has been doubling down on building future revenue streams as its blockbuster immunotherapy, Keytruda, inches closer to losing key patents, opening the doors for competition from biosimilars.
Merck has offered $23 per share in cash for California-based Harpoon, representing a 118% premium to the stock's last close on Friday.
Shares of Harpoon more than doubled premarket on Monday after deal talks were first reported by Bloomberg.