Novo Nordisk raised its offer for obesity biotech Metsera as a rival bid from Pfizer intensified and U.S. antitrust officials publicly flagged the proposed transaction structure. Sources told reporters Novo increased its bid late Wednesday; the Federal Trade Commission’s competition bureau warned in a letter that elements of Novo’s deal could transfer significant rights to Novo before the Hart‑Scott‑Rodino review, potentially violating the HSR Act. The FTC letter, signed by Daniel Guarnera, specifically cited controls and caps that could limit Metsera’s commercial independence while the deal is pending. The regulator’s concerns add legal and timing risk to a high‑stakes fight for obesity assets, a sector dominated by Wegovy and other GLP‑1s where acquisition timelines and regulatory clearance materially affect valuations. Buyout structure and antitrust scrutiny now shape strategic options for both bidders and Metsera’s board. Market participants and lawyers will watch subsequent filings and any remedial steps taken to preserve pre‑merger review rights or to avoid operational restraints that the FTC flagged.