AstraZeneca, Bristol Myers in Early Talks for Potential $400 Bn Pharma Merger

British drugmaker AstraZeneca Plc and US-based Bristol Myers Squibb have held preliminary discussions about a possible merger that could create one of the world's largest pharmaceutical companies with a combined value of nearly $400 billion, according to a Reuters report.

The Financial Times first reported the discussions. Reuters, citing a person familiar with the matter, said the talks were at an early stage and there is no certainty that a transaction will materialise.

If completed, the deal would rank among the biggest pharmaceutical mergers ever and could significantly reshape the global healthcare industry.

Regulatory Hurdles May Be a Major Challenge

A potential merger is expected to face significant regulatory scrutiny, particularly in the United States (US), where antitrust authorities have been taking a closer look at large healthcare deals.

According to the report, one concern is that AstraZeneca, a UK-based company, would effectively acquire a major US pharmaceutical company at a time when President Donald Trump's administration has been encouraging domestic investment and manufacturing.

Andre Barlow, an antitrust lawyer at DBM Law Group, told the news agency that regulators would likely examine overlaps in existing drugs and late-stage pipelines. He said meaningful divestitures could be required if competition concerns arise.

Cancer Drug Businesses Could Draw Attention

Both companies have strong positions in cancer treatments, making oncology one of the biggest areas regulators are expected to examine.

AstraZeneca's cancer medicines generated about $25 billion in sales in 2025, accounting for nearly half of its total revenue. Bristol Myers also derives more than 40% of its sales from oncology drugs, with products such as Opdivo among its key medicines.

Barlow also noted that US regulators have previously required major asset sales in large pharmaceutical mergers. During Bristol Myers' acquisition of Celgene in 2019, the company had to divest psoriasis drug Otezla as part of regulatory approvals.

Both Companies Pursuing Growth

AstraZeneca has continued to expand under Chief Executive Pascal Soriot, with strong demand for its cancer and rare disease medicines supporting growth. The company has also announced plans for a direct US listing to tap deeper capital markets.

Meanwhile, Bristol Myers has been pursuing smaller acquisitions and investing in newer medicines as several of its blockbuster drugs approach patent expiry. Its latest quarterly results exceeded market expectations, prompting the company to raise its full-year revenue and profit forecast.

Large pharmaceutical mergers have become relatively rare in recent years because of tougher antitrust scrutiny and concerns over drug pricing. If AstraZeneca and Bristol Myers decide to pursue a formal deal, it is likely to face an extensive regulatory review before moving ahead.