Pfizer Inc. has filed its second lawsuit in less than a week against Novo Nordisk A/S and biotech firm Metsera, Inc., contending that Novo Nordisk’s attempt to acquire Metsera is an anticompetitive manoeuvre designed to shut down future rivals in the weight-loss (obesity/GLP-1) drug market.
Background:
Novo Nordisk, which currently dominates the market with injectable GLP-1 therapies, moved first into the obesity-drug race. However, rivals — particularly Eli Lilly and Company — have gained ground, and Pfizer, previously sitting on the sidelines, wants in on the action.
In September, Pfizer struck a deal to purchase Metsera for roughly US$4.9 billion upfront, with the total potentially rising to US$7.3 billion with milestone payments.
But nearly simultaneously, Novo Nordisk swooped in with an unsolicited bid topping US$8.5 billion, which Metsera accepted as “superior.”
What Pfizer claims:
In its first suit, Pfizer contended that Novo Nordisk’s offer couldn’t truly be “superior” under the merger agreement, given the regulatory risks it posed — meaning it was unlikely to be completed.
In the second filing, Pfizer pressed an antitrust argument: it alleged that a Novo Nordisk–Metsera deal would breach Section 7 of the Clayton Antitrust Act and Sections 1 & 2 of the Sherman Antitrust Act, accusing the parties of conspiring to monopolise the GLP-1 obesity-drugs market and eliminate an American challenger.
Pfizer also alleges that Metsera’s controlling shareholders — including venture funds and health-investment firms — collaborated with Novo to facilitate this anticompetitive outcome.
Reactions & implications:
Metsera pushed back in a statement, calling Pfizer’s claims “nonsense” and accusing Pfizer of using litigation as leverage to acquire the firm at a lower price.
Novo Nordisk, meanwhile, maintains its proposed acquisition does not raise antitrust issues, noting the obesity-drugs field remains highly competitive with multiple companies developing treatments.
Meanwhile, the stock market is reflecting the uncertainty. Novo Nordisk shares have slipped amid the dispute, while Metsera’s stock has jumped.
Why it matters:
The global market for obesity and metabolic-disease therapies — especially GLP-1 type drugs — is rapidly expanding, potentially reaching hundreds of billions of dollars in the coming years. Companies are fiercely vying for position. A successful acquisition could give Pfizer a fast track into this space, whereas for Novo Nordisk it would reinforce market dominance by swallowing a nascent competitor.
What happens next:
The legal cases are just beginning. Courts will need to weigh the contractual issues (Pfizer’s merger deal with Metsera) and the antitrust arguments (market competition and dominance). The outcome could influence not only the fate of Metsera, but also broader market dynamics in the weight-loss therapies sector.