Metsera's board has announced that a new $10bn offer from Novo Nordisk is a "superior proposal" compared to Pfizer's bid.
This comes after Pfizer filed a second lawsuit against Novo and Metsera, alleging that the Danish drugmaker’s attempt to outbid Pfizer to acquire the obesity biotech is anticompetitive, just two days after a first suit.
Metsera is a small biotech developing next-gen obesity treatments.
It is looking to capture a slice of the market that is currently dominated by Eli Lilly (maker of Mounjaro and Zepbound) and Novo Nordisk (maker of Ozempic and Wegovy).
Currently, it has four ongoing clinical trials for weight loss drugs, including a long-acting monthly injectable and a pill, giving them a competitive advantage compared with existing weight loss treatments that use weekly injectables.
Pfizer had originally agreed a $7.5bn deal with obesity biotech Metsera back in September 2025, including contingent value rights (CVRs) based on future milestones.
The agreement marked Pfizer's attempt to enter the lucrative GLP-1 obesity drug market, following setbacks with its own weight-loss treatments.
Novo Nordisk then submitted a competing offer in October, valuing Metsera at up to $8.5bn, outbidding Pfizer.
This triggered Pfizer to file its first lawsuit in Delaware, claiming the Novo offer breached the existing merger agreement and was anticompetitive, as well as asking the court to block Novo's bid and prevent Metsera from terminating its agreement with Pfizer.
In the second suit, also filed in Delaware, the US drugmaker said Novo’s proposed acquisition of Metsera would “protect its dominant market position in GLP-1s by capturing and killing a nascent American challenger before it gains the support of Pfizer, one of America’s leading pharmaceutical companies."
Metsera itself has also come into Pfizer's line of fire, with the suit alleging that Metsera’s controlling shareholders conspired with the obesity biotech and Novo Nordisk.
Novo Nordisk has responded to the lawsuit, saying it believes its bid does not raise antitrust concerns and that it adhered to the terms of the merger agreement with Metsera.
Metsera has asked the Delaware Court of Chancery to reject Pfizer’s request for a restraining order hearing on Tuesday, intended to block Novo’s bid.
Novo's amended proposal values Metsera at up to $10bn, much more than Pfizer's second, revised offer of $8.1bn.
Metsera's board has said that this offer is a “vastly superior deal” for the company’s shareholders.
Under the terms of the existing merger agreement with Pfizer, this triggers a two-business-day window for Pfizer to negotiate adjustments so that the Novo offer no longer qualifies as "superior".