United States pharmaceutical giant Pfizer has clinched a US$10 billion (A$15.4 billion) takeover of obesity drugmaker Metsera after Danish rival Novo Nordisk walked away from the bidding war, citing antitrust headaches and inflated valuations.
The New York-based drugmaker agreed to pay $86.25 per share - $65.60 upfront with contingent value rights worth up to $20.65 per share tied to clinical milestones.
That's a 3.69% premium to Metsera's Friday close and roughly double Pfizer's original $7.3 billion September bid.
Novo Nordisk bowed out Saturday after the U.S. Federal Trade Commission warned its proposed structure risked violating antitrust laws.
Metsera's board said Novo's offer presented "unacceptably high legal and regulatory risks" compared to Pfizer's proposal, which already secured FTC clearance.
The collapse marks a setback for Novo as it battles to reclaim market share from Eli Lilly in the obesity drug space.
Analysts project the global market could hit $150 billion by the early 2030s, up from roughly $15 billion in 2024.
Pfizer's winning bid hands it access to Metsera's experimental pipeline - notably MET-097i, a GLP-1 injectable, and MET-233i, which mimics the pancreatic hormone amylin.
Neither drug has reached the market yet.
Bernstein analyst Courtney Breen flagged that the price relies on optimistic assumptions.
She calculates Pfizer needs $11 billion in revenue by 2040 - nearly double Metsera's projections - to justify the outlay.
Former Pfizer R&D chief John LaMattina told Reuters the scrap echoed Pfizer's hostile takeover of Warner-Lambert in 2000 for $90 billion to secure Lipitor rights.
"Pfizer must believe that Metsera's pipeline is key to its future," he said.
The deal closes after Metsera's November 13 shareholder meeting.
Pfizer's appetite for obesity assets comes after it scrapped its own weight-loss pill development - making acquisition the fastest route into a market analysts reckon could be worth more than the entire oncology drug sector within a decade.
The bidding war sent Metsera shares surging nearly 60% from just before Novo's initial offer through Friday's close, pushing its market value to $8.75 billion.
A source close to Novo dismissed the deal as a "bolt-on acquisition" that was never "do or die" for the Danish group, which continues advancing its own pipeline.
Novo said it remains "confident" in its obesity treatment portfolio and will keep assessing M&A opportunities that meet its financial discipline criteria.
