Novo Nordisk submitted a higher unsolicited offer for obesity biotech Metsera, prompting an immediate legal and strategic response from Pfizer. Novo’s bid raises the deal value well above Pfizer’s earlier agreement, and Pfizer has accused Novo of structuring a proposal that risks antitrust scrutiny. Metsera’s board has labeled Novo’s proposal “superior,” triggering a four-business-day window for Pfizer to respond. The development has pushed two global pharma giants into an active takeover contest in the hot obesity market, with both companies staking claims over Metsera’s incretin and amylin assets. The dispute now includes litigation threats and antitrust arguments from Pfizer and public maneuvering from Novo, elevating regulatory and competitive risk for the transaction. Investors and dealmakers will watch whether Pfizer raises its offer or pursues legal remedies; either outcome will affect M&A dynamics in obesity and the strategic calculus for biotech sellers. The fight also highlights increased regulatory scrutiny around consolidation in therapeutic areas dominated by a few large players.