New York — Pfizer Inc. said Phase 2b data support monthly dosing of berobenatide, an investigational GLP-1 receptor agonist peptide being developed for chronic weight management and obesity-related conditions.
The company presented detailed results from multiple Phase 2b studies of berobenatide, also known as PF’3944, during a late-breaking expert symposium at the American Diabetes Association’s 86th Scientific Sessions.
Pfizer said the Phase 2 studies were designed to identify doses for Phase 3 development and test escalation approaches. Across weekly and monthly dosing in participants with obesity or overweight, with and without type 2 diabetes, the VESPER-1, VESPER-2 and VESPER-3 studies showed proof of concept for berobenatide as a potential first-in-class monthly GLP-1 receptor agonist peptide.
The company said the data showed competitive weight loss, favorable tolerability, low gastrointestinal adverse events and low discontinuation rates despite rapid dose escalation and no permitted step-down. Pfizer also said the drug could offer convenience and scalability advantages through monthly delivery in a 0.5 mL injection volume.
Results from a 32-week exploratory extension of the Phase 2b VESPER-1 study showed non-placebo-adjusted weight loss of 15.9% with no plateau observed at 32 weeks on 2.4 mg weekly berobenatide. VESPER-1 is evaluating once-weekly berobenatide in adults with obesity or overweight, including an extension assessing the durability of weight loss and the effect of transitioning from once-weekly to less frequent dosing, including once-monthly.
“In Phase 2b studies, berobenatide delivered continuous, uninterrupted weight loss at all doses selected for Phase 3, while preserving a tolerable profile as people transitioned from a weekly to a monthly maintenance dose,” said Jim List, MD, PhD, Chief Internal Medicine Officer, Pfizer. “These data highlight the potential for berobenatide to be the first approved monthly GLP-1 RA peptide and support our extensive Phase 3 program that includes 10 studies for chronic weight management and obesity-related comorbidities. With berobenatide as a potential foundational metabolic medicine, both as a single agent and as a combination backbone, Pfizer is advancing a differentiated pipeline with multiple mechanisms and modalities designed to meet the many needs of people living with obesity and related conditions.”
Pfizer also presented detailed results from the previously reported Phase 2b VESPER-3 study, which is evaluating monthly maintenance dosing of berobenatide in adults with obesity or overweight without type 2 diabetes.
The company said data from VESPER-2, which evaluated weekly dosing in adults with obesity or overweight and type 2 diabetes, showed dose-dependent reductions from baseline in both body weight and HbA1c. Pfizer said berobenatide 1.6 mg weekly achieved a 2.2% reduction in HbA1c at week 28, compared with a 0.2% reduction in the placebo group.
“Weight management is a lifelong commitment, and the barriers to staying on therapy long-term are just as important as the therapy itself,” said John B. Buse, MD, PhD, Professor of Medicine at the University of North Carolina School of Medicine, Chapel Hill. “The growing body of evidence shows berobenatide delivering meaningful weight loss with a well-tolerated profile following a switch from weekly to monthly dosing in Phase 2b studies. If approved, berobenatide has the potential to not only be effective, but practical and sustainable in real life.”
Pfizer said the VESPER-6 pivotal Phase 3 study, which is evaluating monthly maintenance dosing of berobenatide in adults with obesity or overweight, is open for enrollment.
The company also said the SOLIS-1 Phase 2b study is open for enrollment. That study is evaluating weekly and monthly maintenance dosing of an ultra-long-acting amylin analog, PF’3945, as a monotherapy and in combination with berobenatide.
