Pfizer bets $4.9B on Metsera to rejoin the obesity drug race

Pfizer is acquiring obesity drug developer Metsera for $4.9 billion, doubling Metsera’s IPO valuation and marking Pfizer's return to the competitive weight-loss market after prior failures.

Why it matters: Obesity drugs are projected to be a $100B market within five years. With this deal, Pfizer gains access to a promising pipeline it hopes will rival market leaders Novo Nordisk and Eli Lilly.

Backstory: Metsera, which went public in January at $18 per share, will be acquired at $47.50 per share, with up to $22.50 more in milestone-based payouts. Its portfolio includes two once-monthly injectable drugs, GLP-1 agonist MET-097i and amylin mimetic MET-233i, plus a combination version that showed ~8% weight loss in early trials.

Zoom in: Obesity drugs have a massive amount of market potential, which explains why Pfizer is so interested. For example, Novo’s Wegovy and Lilly’s Zepbound each made ~$6B in H1 2025, underscoring the market potential. Metsera emerged only 16 months ago, already had $290M in funding, and licensed obesity candidates.

Big picture: Pfizer’s earlier obesity drugs, lotiglipron and danuglipron, failed in Phase 2, leaving it behind in a high-stakes race. Buying Metsera signals a strategic pivot toward acquiring rather than building in-house solutions. This is confirmed by the beliefs of Pfizer’s R&D chief regarding Metsera’s drugs being key growth drivers for the late 2020s.

Yes, but: Unwilling to let Pfizer get past them, Roche is already planning to begin Phase III trials of its lead obesity drug candidate CT-388 in the first half of 2026. Aiming to become the third-largest player in the obesity drug market by 2030. Roche has taken steps such as purchasing Carmot Therapeutics for multiple billions of dollars in a similar fashion to Pfizer´s purchase of Metsera.