AstraZeneca Investors Balk at Prospect of Near-$400bn Bristol Myers Tie-Up

AstraZeneca (AZN) shares fell sharply after reports emerged of merger talks with US rival Bristol Myers Squibb (BMY), with investors delivering a swift verdict that the British pharmaceutical giant has little need for a deal that would create one of the world's largest drugmakers.

Shares in AstraZeneca dropped roughly 9 percent — their biggest single-day drop since 2020 — while Bristol Myers slipped less than one per cent in early New York trading.

A person familiar with the matter confirmed that the two sides had held talks, corroborating an earlier report by the Financial Times. A spokesperson for AstraZeneca declined to comment; Bristol Myers did not respond to a request for comment.

A completed deal would create the world's fourth-largest drugmaker by market value and the largest by revenue, in what would rank among the biggest M&A transactions ever executed in the pharmaceutical sector.

Investors were unconvinced. "The only advantage for AstraZeneca in this rumored combination with BMS seems to be to accelerate its US footprint and sales," said Lucy Coutts, investment director at JM Finn, a shareholder in the company. "On balance, BMS shareholders would be the winners of any combination with AZN, and so this news will undoubtedly be received coolly by AZN shareholders."

Markus Manns, portfolio manager at Union Investment, another AstraZeneca shareholder, said the deal "does not make strategic or financial sense" and would disrupt a "well-run company with a full pipeline." He likened the proposal to FIFA's since-abandoned plans to sell a stake in the World Cup — "a poorly conceived proposal that would be met with considerable bewilderment by many market participants."

Lukas Leu, portfolio manager at ATG Healthcare, acknowledged that a merger could boost margins through cost synergies and expand the combined group's reach in neuroscience and cell therapy, but said he was "not a big fan of mega-mergers" given the toll such transactions typically take on innovation and agility. He described any deal as "growth-dilutive for AstraZeneca in the near term."

A portfolio manager at a top-20 AstraZeneca shareholder, speaking anonymously, said that while "there may be an appeal to increasing US exposure," the move "would be a surprise given Astra management has consistently backed the business to grow organically through R&D delivery." The source added: "Consensus is that Astra has a stronger pipeline and less patent expiry pressure than BMS, so why dilute that and reduce the growth outlook?"

One rationale for the deal centers on the US market, already AstraZeneca's largest. The company completed a direct listing on the New York Stock Exchange earlier this year and has invested tens of billions of dollars in US manufacturing since President Donald Trump returned to office, cultivating close ties with his administration as it pursues an ambitious target of generating half of a projected $80bn in annual revenue from the US by 2030. The group posted approximately $59bn in revenue last year.

Sean Conroy, an analyst at Shore Capital, said a deal could help AstraZeneca address the patent cliff it faces after 2030 and bolster its oncology franchise, though he cautioned that investors are "not often fans of mega mergers of this ilk." He also flagged potential antitrust complications stemming from the overlap between Bristol Myers' Opdivo and AstraZeneca's Imfinzi, which compete in the same class of cancer immunotherapy.