A Pfizer logo is displayed at a research center in the La Jolla neighborhood of San Diego, California, United States, September 30, 2025.
Mike Blake | Reuters
Pfizer said on Monday that it had filed a second complaint against Novo Nordisk And Metseraalleging that the Danish pharmaceutical manufacturer’s attempt to outbid Pfizer to acquire obesity biotechnology is anti-competitive.
Pfizer alleges that Ozempic maker Novo Nordisk’s proposed acquisition of Metsera would help it maintain its dominant position in the blockbuster obesity market by eliminating a smaller potential competitor, according to the lawsuit filed Monday in U.S. District Court in Delaware. The suit also alleges that Metsera’s majority shareholders conspired with the obesity biotechnology company and Novo Nordisk.
In a statement Monday, Ambre James Brown, Novo Nordisk’s vice president of global media, said Pfizer’s “baseless claims that Novo Nordisk intends to suppress innovation through our offering are false and baseless.”
“Instead of competing on price, Pfizer took a very unusual and seemingly desperate approach by filing an antitrust lawsuit today,” Brown said. She added that Novo Nordisk’s offer, including the structure of the transaction, complies with all applicable laws and is in the “best interests” of patients and Metsera shareholders.
In a statement, Metsera said: “Pfizer is trying to argue to buy Metsera at a lower price than Novo Nordisk.” The company added that Pfizer’s arguments “are absurd and Metsera will address them in court.”
The new suit escalates a heated standoff between Pfizer and Novo Nordisk over Metsera, whose obesity pipeline could give rise to new competitors in the booming weight-loss drug market. Pfizer announced in September that it would acquire Metsera for $4.9 billion, or up to $7.3 billion with future payments — a deal that could be the company’s golden ticket into the industry after struggling to market its own obesity products.
But Novo Nordisk launched a tender offer Thursday valuing the biotech at about $6 billion, triggering a four-business-day delay for Pfizer to renegotiate its offer. Pfizer filed its first lawsuit against Novo Nordisk and Metsera on Friday, seeking to prevent the biotech from terminating its existing merger agreement with Pfizer.
This lawsuit, filed in the Delaware Court of Chancery, alleges that Novo Nordisk’s offer cannot be considered a superior proposal because it is reasonably unlikely to be consummated due to its significant regulatory risk.
Novo Nordisk helped establish the weight-loss drug industry, bringing highly effective GLP-1 drugs to market, including the Ozempic diabetes injection and the Wegovy obesity injection. But the company lost its market leadership position to its main rival, Elie Lillyover the past year and has struggled to impress investors with its pipeline.
