Pfizer Sues Novo Nordisk Over Alleged Tactics to Block Obesity Drug Competition

Pfizer has filed a second lawsuit against Danish pharmaceutical giant Novo Nordisk, accusing the company of deliberately stalling its $9 billion bid for biotech firm Metsera to hinder competition in the booming obesity drug market. The U.S. drugmaker argues that Novo’s actions are designed to delay Metsera’s drug development and maintain its dominance alongside Eli Lilly in the GLP-1 obesity treatment space.

The legal battle follows a tense bidding war between Pfizer and Novo for Metsera, which develops next-generation obesity drugs with the potential for monthly injections — a major advancement over the weekly regimens of Novo’s Wegovy and Lilly’s Mounjaro. Pfizer initially reached a $7.3 billion deal with Metsera in September, but Novo continued its pursuit, submitting a seventh unsolicited bid last week following a leadership shakeup led by its top investor.

Metsera’s board, reversing its earlier position, declared Novo’s latest offer “superior” and gave Pfizer until Tuesday to improve its bid. Pfizer responded by filing two lawsuits — one in Delaware’s Court of Chancery against Metsera’s board and Novo, and another federal antitrust complaint on Monday, alleging that Novo’s proposal is a strategic ploy to delay market competition. Pfizer claims Novo’s offer uses a 30-month “outside date” to stall Metsera’s progress, compared to Pfizer’s nine-month merger timeline, which had already cleared antitrust review.

Novo Nordisk and Metsera have both dismissed Pfizer’s allegations as baseless. Novo insists its bid complies fully with merger regulations, while Metsera accused Pfizer of attempting to manipulate the process to lower the acquisition price. A Delaware judge will hear the case Tuesday, marking a critical moment in the escalating fight over control of Metsera and the lucrative obesity drug market projected to reach $150 billion annually.