Pfizer - Vesper-1 shows nearly 16% weight loss at 32 weeks on 2.4 mg weekly berobenatide

Pfizer Inc. (NYSE: PFE) has reported positive findings from its VESPER-1 open-label extension trial, which evaluated the investigational GLP-1 receptor agonist berobenatide (MET-097, PF-08653944) in adults with obesity or overweight without type 2 diabetes. Participants receiving a 2.4 mg weekly dose of berobenatide achieved nearly 16% weight loss over 32 weeks, according to data presented at the 86th Scientific Sessions of the American Diabetes Association. The results highlight the potential of berobenatide as a long-acting GLP-1 RA with a favorable tolerability profile and sustained efficacy.

The VESPER program includes multiple trials assessing berobenatide across different dosing regimens and patient populations. VESPER-1 focuses on weekly dosing, while VESPER-3 evaluates monthly administration. Both studies are part of an extensive clinical development program aimed at addressing gaps in obesity care and improving treatment adherence through less frequent dosing. The 2.4 mg weekly dose tested in VESPER-1 aligns with ongoing efforts to optimize therapeutic outcomes while minimizing gastrointestinal side effects, a common challenge with GLP-1 RA therapies.

Pfizer plans to advance 10 Phase 3 trials of PF’3944 in 2026, including VESPER-4 and VESPER-5, which will investigate the drug in patients with and without type 2 diabetes. The company’s obesity pipeline also includes combinations with amylin analogs and GIPR agonists, reflecting a broader strategy to address comorbidities associated with obesity. These developments underscore Pfizer’s commitment to expanding its portfolio of weight management therapies and enhancing patient access to innovative treatments.

The VESPER-1 open-label extension data will be further analyzed to inform long-term safety and efficacy assessments. Researchers will also present findings from VESPER-2 and VESPER-3 at the 2026 Scientific Sessions, providing insights into the drug’s potential across diverse patient populations. With the obesity epidemic projected to affect over 2.9 billion people by 2030, the development of effective, well-tolerated therapies remains a critical priority for the pharmaceutical industry.