Metsera's Obesity Drug Shows Promise, Strengthening Pfizer's $4.9 Billion Acquisition

Metsera's experimental obesity drug, MET-097i, has demonstrated significant weight loss efficacy in a recent Phase 2 trial, bolstering Pfizer's decision to acquire the company for $4.9 billion. The results, announced on Monday, reveal that the drug's performance closely mirrors that of Eli Lilly's Zepbound, potentially positioning Pfizer as a formidable competitor in the rapidly expanding obesity treatment market.

Phase 2 Trial Results and Tolerability Profile

In the 28-week Phase 2 trial, participants receiving the highest dose of MET-097i experienced an average weight loss 14 percentage points greater than those on placebo. This outcome is comparable to the 13% placebo-adjusted weight loss achieved by Zepbound at the same stage in its Phase 3 Surmount-1 study.

Notably, Metsera reported that only two of the 239 study volunteers discontinued treatment due to side effects, suggesting a favorable tolerability profile. An ongoing trial evaluating a titrated dosing regimen has shown promising interim results, with reduced gastrointestinal side effects compared to existing GLP-1 drugs for obesity.

The titrated dosing approach, involving a three-step regimen culminating in a 1.2 milligram injection, resulted in nausea and vomiting rates 13 and 11 percentage points higher than placebo, respectively. These figures compare favorably to Zepbound's prescribing information, which cites nausea rates up to 21 points higher than placebo.

Implications for Pfizer and the Obesity Drug Market

Pfizer's acquisition of Metsera, expected to close by year-end, marks the pharmaceutical giant's re-entry into the obesity drug development arena. The company had previously abandoned two internal candidates due to safety concerns. With projections suggesting the obesity treatment market could exceed $100 billion in annual sales by the next decade, Pfizer's strategic move positions it to compete with established players like Eli Lilly and Novo Nordisk.

The positive Phase 2 results for MET-097i pave the way for Pfizer to initiate more comprehensive Phase 3 studies, which will assess weight loss effects over treatment periods exceeding one year. As the obesity drug landscape continues to evolve, the development of medications with improved efficacy and tolerability profiles remains a key focus for pharmaceutical companies vying for market share in this lucrative therapeutic area.