Pfizer's monthly injectable GLP-1 drug shows weight loss in Phase 2b study
Pfizer's novel, ultra-long-acting injectable GLP-1 receptor agonist PF-08653944 has demonstrated significant weight loss with monthly dosing in a Phase 2b trial.
New York – Pharmaceutical giant Pfizer announced positive topline results from its Phase 2b VESPER-3 study evaluating the monthly maintenance dosing of its ultra-long-acting injectable GLP-1 receptor agonist (GLP-1 RA) PF-08653944 (MET-097i).
The study targeted adults with obesity or overweight without type 2 diabetes. Its objectives were to show that the drug could maintain weight loss when switching from weekly to monthly dosing, quadrupling the dosing frequency, while preserving efficacy and a favorable tolerability profile.
The study's primary endpoint, weight reduction at 28 weeks compared to placebo, was statistically significant across all four tested dose regimens. Mean placebo-adjusted weight loss reached up to 12.3%. Weight loss continued after the transition from weekly to monthly dosing, with no plateau observed at 28 weeks.
PF-08653944 also maintained a well-tolerated and favorable safety profile through week 28, consistent with the GLP-1 RA class. Gastrointestinal adverse events were predominantly mild to moderate. Pfizer plans to advance ten Phase 3 trials for PF-08653944 in 2026.