On Feb. 23, 2026, Gilead Sciences announced it will buy cancer therapy partner Arcellx for an implied equity value of $7.8 billion, expanding their cell therapy development collaboration that started in 2022.

Shares of Arcellx climbed 77.8% to $113.99 while Gilead fell about 1% in premarket trading. Gilead will pay $115 per share in cash at the deal’s closing, which is at a premium of 79% to the stock’s last close.

Kite Pharma, a unit of Gilead Sciences, was partnering with Arcellx to jointly develop and sell anito-cel, an experimental CAR-T therapy for multiple myeloma, a type of blood cancer.

CAR-T cell therapy is a cancer treatment that uses a patient’s own genetically modified immune cells to find and kill cancer cells. The U.S. Food and Drug Administration (FDA) is currently reviewing the therapy, with a decision expected by December 23, 2026.

Upon FDA approval of anito-cel, the proposed transaction is expected to be accretive to earnings per share in 2028 and thereafter. Gilead will also pay Arcellx shareholders $5 per share, contingent upon the achievement of cumulative global net sales of anito-cel of at least $6 billion from launch through year-end 2029.