AstraZeneca is reportedly exploring a major U.S. acquisition that would rank among the largest deals ever in the pharmaceutical sector, potentially creating a company valued at approximately $400 billion.

The industry has largely avoided acquisitions at this scale for more than 10 years. Rumored discussions involve Bristol Myers Squibb, which faces a deteriorating long-term growth outlook as several key products approach patent expiration.

AstraZeneca, one of Britain's most valuable listed companies, has set a target of $80 billion in revenue by 2030—an ambition built on scientific risk-taking, substantial U.S. investment and a robust China business. The company already commits $50 billion to U.S. research and development alongside manufacturing operations.

Not all analysts support the move. Writing in The Guardian, Nils Pratley said AstraZeneca should stick with its current formula. Pratley said CEO Pascal Soriot risks pulling the company into the U.S. pharmaceutical establishment unnecessarily, given its existing $50 billion U.S. footprint. He said a $400 billion merger is not essential for AstraZeneca to hit its 2030 targets and that the company has a strong track record without large-scale integrations.