Just days after CEO Daniel O’Day told investors M&A wasn’t an urgent priority, Gilead Sciences dropped $7.8 billion to gobble up Arcellx — the biotech partner it’s been courting since 2022.
The deal pays Arcellx shareholders $115 per share in cash, a 79% premium to Friday’s close. Shares of Arcellx rocketed 78% on the news Monday morning. Gilead dipped about 1%. Classic acquirer-target dynamic — the buyer always bleeds a little.
The prize is anito-cel, an investigational CAR-T cell therapy targeting multiple myeloma, one of the most common and deadly blood cancers. CAR-T works by reprogramming a patient’s own immune cells to hunt and destroy cancer cells. It’s the cutting edge of oncology, and the clinical data so far is staggering: a 97% overall response rate in the pivotal Phase 2 iMMagine-1 trial, with 68% of patients hitting complete or stringent complete response. Six-month progression-free survival came in at 91.9%. Those are the kind of numbers that get the FDA’s attention.
Speaking of the FDA — the agency is currently reviewing anito-cel, with a target decision date of December 23, 2026. If approved, Gilead expects the acquisition to add to earnings per share by 2028. There’s also a sweetener: $5 per share in contingent payments to Arcellx shareholders if cumulative global net sales of anito-cel hit $6 billion by year-end 2029.
This isn’t Gilead’s first massive cell therapy bet. Its Kite Pharma subsidiary has been bankrolling Arcellx since a 2022 partnership that included a $225 million upfront payment and $100 million equity investment. In October 2025, Kite signed a $1.5 billion deal with China’s Pregene. In January, it committed $300 million to OncoNano Medicine. The message is unmistakable: Gilead is going all-in on cell therapy as its next growth engine, and it’s willing to write very large checks to get there.
For investors, the calculus comes down to one question: can anito-cel deliver in the real world? Multiple myeloma treatments already generate over $20 billion in annual global sales. If those near-perfect response rates translate outside clinical trials, $6 billion in cumulative sales isn’t just achievable — it might be conservative. A Phase 3 trial pitting anito-cel against standard-of-care treatments is currently enrolling 450 patients, with results expected by mid-2028.
The risk is obvious: the FDA. A December rejection would make this $7.8 billion bet look spectacularly expensive. But with a 97% response rate and a partner that’s been building toward this moment for four years, Gilead is betting the science speaks louder than the skeptics.