AstraZeneca Plc is reportedly negotiating a $400 billion acquisition of Bristol Myers Squibb Co., a deal that would create one of the world’s largest drugmakers. The talks, ongoing for several months, could soon close, though delays or collapse remain possible, according to the Financial Times.

If completed, AstraZeneca would become the fourth‑largest drugmaker by market cap, with a value of $263 billion compared to Bristol Myers Squibb’s $133 billion. The merger would expand AstraZeneca’s presence in the U.S., raising concerns in the UK over a shift of focus abroad. The structure is yet to be decided but likely involves cash and shares.

Both companies have sizable cancer divisions that could attract antitrust scrutiny, and the deal would surpass AstraZeneca’s $39 billion acquisition of Alexion in 2021. Bristol Myers Squibb has been boosting its drug discovery through AI partnerships, including a collaboration with Anthropic, potentially accelerating development alongside AstraZeneca’s oncology research.

The merger’s success depends on regulatory approval and market reactions, and it would combine two leading drugmakers’ pipelines, potentially benefiting patients worldwide.