BENGALURU: Merck & Co has agreed to acquire Prometheus Biosciences Inc for about $10.8 billion to bolster the company’s presence in immunology, the companies said on Sunday.

The joint statement said that Merck, through one of its subsidiaries, will pay $200 per share for the biotechnology company that specializes in products for treatment of immunological diseases. That represents a 75% premium to the $114.01 closing price for Prometheus shares on Friday.

Prometheus had a market capitalization of $5.42 billion at Friday’s close.

Merck has been looking for deals to protect itself from eventual revenue loss as patents on its cancer immunotherapy Keytruda begin to expire towards the end of the decade.

“The agreement with Prometheus will accelerate our growing presence in immunology where there remains substantial unmet patient need. This transaction adds diversity to our overall portfolio,” said Merck Chairman and Chief Executive Robert Davis.

The deal, which was first reported by the Wall Street Journal, is expected to close in the third quarter of the year, the companies said.

Merck in February forecast 2023 earnings below Wall Street estimates and an expected steep decline in sales of its COVID-19 antiviral treatment.