Months of legal challenges, court rulings, and regulatory probes define the industry’s fiercest metabolic takeover fight
Pfizer has signed a definitive agreement to acquire metabolic biotech Metsera, ending months of one of the most aggressive takeover battles in recent biopharma history. The deal concludes a dramatic contest with Novo Nordisk, which had initially secured Metsera’s board recommendation with a rival $10 billion offer before becoming entangled in litigation and regulatory review.
The Metsera acquisition saga began in early 2025, when both companies targeted the metabolic drug developer for its portfolio of dual- and tri-agonist peptide therapies addressing obesity, diabetes, and related cardiometabolic conditions. Metsera’s early-stage pipeline attracted intense strategic interest as global demand for GLP-1 and GIP-based drugs surged, transforming obesity treatment into one of pharma’s most lucrative markets.
Pfizer, facing a gap in its metabolic pipeline following setbacks in its own GLP-1 programs, was the first to approach Metsera, offering a reported $9 billion in a mix of cash and milestone-based payments. Novo Nordisk countered soon after with a $10 billion all-cash offer, citing synergies with its established GLP-1 franchise, including Wegovy and Ozempic.
In June 2025, Metsera’s board declared Novo Nordisk’s proposal a “superior offer”, citing certainty of payment and strategic alignment. Pfizer matched the valuation and accused Novo of breaching confidentiality agreements from earlier collaboration talks. That dispute escalated into a Delaware Chancery Court case, where Pfizer sought an injunction to block the merger, claiming Novo had used proprietary information to outbid it.
The Delaware court denied Pfizer’s motion, finding insufficient evidence of contractual violation or irreparable harm. The ruling cleared the way for Novo Nordisk to proceed with its acquisition at least temporarily and represented a significant legal victory for the Danish drugmaker.
However, just weeks after the court decision, Novo Nordisk’s momentum was halted when the U.S. Federal Trade Commission (FTC) launched an antitrust review of the Metsera deal. Regulators raised concerns that the acquisition could consolidate too much control in the obesity and metabolic disease market, an area already dominated by Novo’s blockbuster GLP-1 drugs. The FTC inquiry focused on whether Novo could leverage Metsera’s dual-agonist pipeline to limit future competition or delay rival innovation.
Sources familiar with the review said the FTC was particularly interested in Metsera’s preclinical multi-pathway agonists, which target GIP, GLP-1, and glucagon receptors mechanisms similar to Novo’s own next-generation assets. The scrutiny placed Novo’s acquisition on hold and effectively reopened strategic opportunities for Pfizer, which began renewed talks with Metsera’s board under an exclusivity agreement in October.
Pfizer moved swiftly to re-engage, this time leveraging the regulatory uncertainty surrounding Novo’s offer. The company presented a restructured bid valued at roughly $10 billion, matching Novo’s price but with added incentives including retention packages for Metsera’s R&D teams and performance-based milestones. The bid also included commitments to maintain Metsera’s operations as a semi-autonomous research division within Pfizer’s internal medicine unit.
By early November, after weeks of negotiations and parallel FTC proceedings, Metsera’s board announced it had signed a definitive merger agreement with Pfizer, formally rejecting Novo Nordisk’s stalled offer. The board cited “regulatory feasibility, operational continuity, and long-term innovation value” as decisive factors in the selection.
Pfizer CEO Albert Bourla described the deal as a pivotal moment for the company’s metabolic ambitions. “Metsera’s pipeline represents the next generation of metabolic science,” Bourla said. “This acquisition strengthens our position in one of the fastest-growing therapeutic categories and underscores Pfizer’s ability to execute amid complex competitive dynamics.”
Novo Nordisk, in a statement following the board’s reversal, said it remained “confident in the scientific and strategic merit of its proposal” but would not appeal the decision while the FTC review remains active. Industry analysts noted that while Novo’s legal position had held in Delaware, the regulatory delay proved insurmountable. “Novo had the stronger legal footing, but Pfizer had the timing advantage,” said one analyst. “FTC scrutiny changed the calculus.”
The FTC review of Novo’s proposal is still ongoing, though it is expected to conclude following Pfizer’s closure of its own transaction. Regulators are reportedly considering broader guidelines for M&A activity in the metabolic drug market, reflecting growing concerns about concentration in the obesity sector.
For Pfizer, the acquisition provides immediate scientific depth and strategic validation. Metsera’s assets include early-stage peptide conjugates and small-molecule analogues designed to improve metabolic control, insulin sensitivity, and weight reduction through multi-pathway agonism. Analysts expect Pfizer to integrate Metsera’s lead programs into its own GLP-1 and GIP portfolio and potentially accelerate clinical timelines through its global R&D infrastructure.
Novo Nordisk’s setback does little to diminish its dominance in the GLP-1 field, but it underscores the shifting regulatory landscape surrounding high-value metabolic acquisitions. With the FTC showing renewed willingness to scrutinize consolidation, large-scale biopharma deals face growing hurdles.
The Metsera takeover spanning bidding wars, litigation, and regulatory action now stands as a defining case study in modern pharma M&A. Pfizer’s final victory highlights how timing, compliance, and regulatory strategy can outweigh even the most favourable court ruling in a sector where innovation, scale, and policy increasingly collide.