Drug giant Bristol Myers Squibb Co will buy MyoKardia Inc for $13.1 billion in cash in a deal to expand its offering of heart therapies.

Bristol Myers, which clinched the largest pharmaceutical deal in history just last year, will pay $225 a share for MyoKardia, according to a statement on Monday from the companies, a premium of 61 per cent over the biotech stocks’ Friday closing price.

With the purchase, Bristol Myers gets access to MyoKardias lead product mavacamten, an experimental drug that treats obstructive hypertrophic cardiomyopathy, in which the heart muscle becomes abnormally thick. Expanding Bristol Myerss lineup of heart drugs would help the company maintain a more diversified lineup of therapies after emphasizing the expansion of its oncology business in recent years. The blood thinner Eliquis remains its top-seller, though it is expected to face more competition in coming years.

“We’ ve been thinking about other ways we can strengthen the company, and in particular, the other side of the decade,” said Chief Executive Officer Giovanni Caforio in an interview. “This is a disease with no available treatment, and the value is very significant.”

“It can really be a multi-billion dollar asset,” he said.

Brisbane, California-based MyoKardias shares rose 58 per cent to $220.94 at 10:24 a.m. in New York. Bristol Myers fell 0.4 per cent to $58.50.

Growth Prospects

Nearly a year ago, Bristol Myers closed its $74-billion takeover of Celgene Corp., moving it up the ranks of companies leading the charge in an increasingly competitive field for cancer therapies. But investors have remained concerned that the new combined company will have few growth prospects in the latter half of the decade. Revlimid, the main drug obtained in the deal, is expected to lose US patent exclusivity in 2027, and Eliquis is expected to lose exclusivity in 2026.

An application for approval of mavacamten is expected to be submitted in the first quarter of next year, according to the statement. Executives said on a call that its too early to discuss the drugs potential price.

“The MyoKardia purchase surprised us, given our assumption that the company would first take its time to pay down debt from its Celgene acquisition,” Bloomberg Intelligence analyst Sam Fazeli said in a note to investors. “The fit is clear, though, as Bristol can slot Myokardias mavacamten for hypertrophic cardiomyopathy right next to its Eliquis, another heart drug.”

Hypertrophic cardiomyopathy is a chronic condition in which the the heart wall thickening makes it harder for the organ to pump blood. Its estimated to affect about one in 500 people, according to the statement.

Trials complete

Bristol Myers plans to explore other uses for the drug and to develop additional experimental compounds from MyoKardia.

Contrary to some of the other deals that may be done, this phase 3 program has been completed, Caforio said. This is not an acquisition that will put significant strain on our R&D spend.

The New York-based pharmaceutical company said it plans to finance the acquisition with a combination of cash and debt. Bristol Myers has debt of more than $47 billion.

Caforio said he is confident the company will continue to pursue deals large and small. “Deleveraging remains a really important priority to us,” he said, “but when we see an asset that’s uniquely value-generating for us, we will move swiftly and do larger deals as well.”