Pfizer's $4.9B Bet on Metsera's Obesity Drug Shows Promise in Mid-Stage Trial

Pfizer's recent decision to acquire Metsera for $4.9 billion appears to be paying off, as the biotech company's investigational long-acting GLP-1 therapy, MET-097i, has demonstrated encouraging results in a mid-stage clinical trial. The drug, a once-monthly subcutaneous injection, is poised to become a significant player in the competitive obesity treatment market.

Impressive Weight Loss Results

In the Phase IIb VESPER-1 trial, MET-097i achieved a 14.1% placebo-adjusted weight reduction at 28 weeks with a 1.2-mg dose. Some individual responses reached as high as 26.5%, showcasing the drug's potential efficacy. Analysts at Leerink Partners noted that these results are "very encouraging," comparing favorably to Eli Lilly's blockbuster drug tirzepatide, which achieved about a 13% placebo-adjusted weight loss over the same duration.

The study's findings have bolstered confidence in Pfizer's acquisition strategy. BMO Capital Markets analysts stated that the readout "bodes well for the proposed acquisition... by Pfizer," adding that it "gives credence not only to the Metsera asset but also the internal due diligence in sourcing the deal."

Promising Safety Profile

Alongside efficacy data, Metsera unveiled tolerability findings from another Phase IIb study, VESPER-3. Over 12 weeks of follow-up, the placebo-adjusted risk of common side effects associated with GLP-1 therapies was relatively low:

• Nausea: 12.8% to 23.9% across all dose arms
• Diarrhea: 0% to 11%
• Vomiting: 9.2% to 17%

Leerink analysts suggest that these safety findings indicate "promise for the tolerability profile of MET-097i to be better than tirzepatide in SURMOUNT-1," although they cautioned that the longer duration of Lilly's trial (72 weeks) allowed more time for adverse events to accrue.

Future Developments and Market Potential

With these positive results, Metsera is set to begin a late-stage program for MET-097i later this year. The company is also exploring combination therapies, testing MET-097i with an amylin analog and a GIP receptor agonist. Additionally, Metsera is working on an oral formulation of MET-097i and a prodrug version for maintenance dosing, potentially expanding the drug's market reach and patient convenience.

As obesity continues to be a global health concern, the success of MET-097i could position Pfizer as a major competitor in the lucrative weight loss drug market, challenging established players like Eli Lilly and Novo Nordisk. The pharmaceutical giant's substantial investment in Metsera underscores the industry's growing focus on developing innovative treatments for obesity and related metabolic disorders.