AstraZeneca, Bristol Myers in talks on $400 billion pharma megadeal

UK drugmaker AstraZeneca has been exploring a deal to combine with US rival Bristol Myers Squibb, the Financial Times reported Sunday, citing people familiar with the matter — a tie-up that would create one of the world's biggest pharmaceutical groups with a combined value of nearly $400 billion.

"The companies have held talks on a potential tie-up in recent months," the FT reported, citing people familiar with the matter, adding that a deal could materialise soon but could also be delayed or fall apart. AstraZeneca declined to comment, while Bristol Myers did not immediately respond to a request for comment outside regular business hours. Reuters could not immediately verify the report.

A combination would rank among the largest in corporate history and would draw intense antitrust scrutiny from regulators in the US, UK and EU. It comes about a dozen years after AstraZeneca fended off a takeover attempt by larger US rival Pfizer, which walked away from an $118 billion bid in 2014 after AstraZeneca's board rejected the approach as undervaluing the company.

Cancer Franchise Drives Growth

AstraZeneca's second-quarter results last week showed strong demand for cancer and rare disease drugs continues to drive growth. Cancer treatments accounted for about $25 billion in 2025 sales, nearly half of the total, followed by cardiovascular, renal and metabolism treatments worth about $12 billion.

The company's share price has more than quadrupled during Pascal Soriot's 14-year tenure as chief executive, soaring above the wider FTSE 100 index and main British rival GSK. Last year, AstraZeneca unveiled plans for a direct US listing, aiming to capitalise on stronger valuations in the US market while remaining listed in London — a move that gives it a natural currency for a stock-based transaction with a US counterpart.

Bristol Myers, for its part, brings a portfolio centred on oncology and immunology, including blockbuster drugs that complement AstraZeneca's own cancer franchise. A combined group would hold one of the deepest oncology pipelines in the industry, spanning early-stage research through late-stage trials, and would command pricing power across multiple therapeutic areas. The two companies' overlapping focus on immuno-oncology would be a central focus for any antitrust review, given the concentration it would create in a category that already accounts for a large share of global cancer drug spending.

Regulatory and Strategic Hurdles

A deal of this scale would face a lengthy review process. The last time two pharmaceutical giants pursued a combination of comparable magnitude, regulators on both sides of the Atlantic imposed conditions before clearing the transaction. Antitrust authorities in Washington, London and Brussels would scrutinise overlaps in oncology, immunology and rare disease portfolios, potentially forcing divestitures of key assets and extending the timeline well beyond the initial announcement.

The structure of any transaction also remains an open question. AstraZeneca's direct US listing, announced last year, positions it to offer stock to Bristol Myers shareholders while preserving its London listing, a dual-listing structure that would require approval from both the UK Financial Conduct Authority and US securities regulators. A cash-and-stock mix would need financing at a scale that would test even the largest banks' balance sheets.

If the talks collapse, AstraZeneca retains its independent growth path, with its oncology portfolio and US listing plans intact. If they succeed, the combined group would reshape the sector, putting pressure on rivals including GSK, Merck and Roche to respond with their own consolidation. Investors will watch for any formal announcement, with the FT reporting a deal could materialise soon.

This article is for informational purposes only and does not constitute investment advice.