Bristol-Myers Squibb Company is shoring up its cancer treatment pipeline and immunotherapy arm with an acquisition and a new research partnership. Bristol-Myers Squibb will take over the privately held cancer drug development company Flexus Biosciences for $1.25 billion, earning rights to a budding immunotherapy treatment for cancer that has yet to undergo clinical trials, the companies announced on Monday. In a separate announcement, Bristol-Myers Squibb said it will also collaborate with Rigel Pharmaceuticals through a $330 million partnership anchored by another class of related cancer therapies.

The strategy of both Flexus and Rigel in developing treatments has been to boost the body’s immune system to ward off cancer. The Flexus approach targets a type of cell thought to be partially responsible for allowing tumors to grow by suppressing the immune system of cancer patients, as reported by MarketWatch. Though four of the eight cancer drugs that Bristol-Myers Squibb currently has in development broadly focus on leveraging a patients’ immune system to fight off cancer, none of them work by this mechanism, according to Reuters.

“Bristol-Myers Squibb is committed to leading scientific advances in immuno-oncology and our acquisition of Flexus will expand our innovative pipeline with an important approach to enhancing immune responses in cancer,” Francis Cuss, chief scientific officer for Bristol-Myers Squibb, said in a statement. Bristol-Myers Squibb will purchase all the outstanding capital stock of Flexus in an initial investment of $800 million with the potential for $450 million in additional payments if milestones are hit.

Flexus shareholders will form a new entity to keep all staff and facilities of the two-year-old company intact, and continue developing several other aspects of its immunotherapy programs including a few products enrolled in the first of three phases of clinical trials.

In addition to the Flexus deal, Bristol-Myers Squibb also announced a $330 million partnership with Rigel Pharmaceuticals on Monday. Rigel has developed several immunotherapy drugs that have shown efficacy in preclinical tests, according to a statement, and Bristol-Myers Squibb will earn the ability to develop and commercialize several of its candidates for cancer treatments. 

Bristol-Myers shares rose 1.25% to $61.27 in Monday's morning trading.