Pfizer has initiated litigation to block Novo Nordisk’s unsolicited takeover bid for Metsera, after Novo publicly offered a higher, two‑step proposal. Pfizer alleges Novo’s structure is designed to evade antitrust review and is not reasonably likely to close, while Metsera’s board has described the offer as a "superior company proposal." The dispute creates a compressed window for Pfizer to renegotiate or seek court relief. The legal clash follows a month in which Pfizer agreed to acquire Metsera and then faced a higher unsolicited bid from Novo that values Metsera at roughly $6.5–$9 billion depending on contingent payments. The filings and public statements from Pfizer and Novo set up a likely bidding contest with significant strategic implications for the obesity drug market and antitrust scrutiny of large incumbents acquiring innovative biotechs. Market players will watch whether regulators view Novo’s two‑step structure as a legitimate transaction or a maneuver raising competition concerns. The case highlights how high‑stakes M&A in obesity—where GLP‑1 and next‑gen peptide portfolios matter—can trigger both legal and political escalation.