With Juno, Celgene will gain research into a novel class of therapies known as CAR-T that use the body’s own immune system to fight cancer. The Summit, New Jersey-based company will pay $87 a share in cash, according to a statement Monday. That’s 91 percent above Juno’s closing price Jan. 16, the last trading day before the Wall Street Journal reported the companies were in talks.

Celgene is doubling down on cancer drugs after suffering a major setback last year that sent its market value tumbling. The company’s top-selling blood cancer drug, Revlimid, is expected to face competition in about four years, and the failure of a high-profile experimental candidate for Crohn’s disease in a late-stage trial in October heightened the pressure to find new drivers for long-term growth.

Celgene and Juno already had ties. The two firms first struck a partnership in 2015 to research cancer treatments, and Celgene was Seattle-based Juno’s largest shareholder, with a stake of about 10 percent.

The value of the deal is net of cash and marketable securities held by Juno, and of Juno shares already owned by Celgene. The transaction was approved by the boards of directors of both companies.

Juno’s stock rose 27 percent to $86.20 at 7:06 a.m. in New York, before the markets opened. Celgene was little changed at $102.55.

The purchase of Juno, shortly after Celgene agreed to buy Impact Biomedicines Inc. for at least $1.1 billion, is part of Celgene’s plan to help offset lost revenue from Revlimid once copycat drugs are on the market.

CAR-Ts are bespoke treatments that re-engineer the body’s own immune system cells to make them attack cancers, and, so far, they have shown the biggest promise in blood cancers, a disease area in which Celgene specializes.

The Juno deal gives Celgene an entry in a breakthrough field. The first CAR-T to win approval from U.S. regulators was a Novartis AG treatment, last August, followed in October by Yescarta, a product Gilead Sciences Inc. had just bought as part of its $12 billion acquisition of Kite Pharma.

Juno is among the furthest along in the development of treatments in the field, according to Brad Loncar, an investor who founded an exchange-traded fund that tracks such therapies.

“Other than Kite, which is already spoken for, and Novartis, which is obviously a huge pharmaceutical company, there’s really no asset like Juno,” he said in a interview on Jan. 17. “This is going to be a trend that could majorly disrupt cancer treatment over a decade and this is just the very beginning of that.”

The transaction is expected to close in the first quarter. J.P. Morgan Securities LLC is advising Celgene and Morgan Stanley & Co. LLC is working for Juno. Celgene’s legal counsel is Proskauer Rose LLP and Hogan Lovells, while Juno is working with Skadden, Arps, Slate, Meagher and Flom, LLP.