Pfizer recently presented detailed results from multiple phase 2b studies of berobenatide (PF’3944), an investigational, potential first-in-class monthly GLP-1 receptor agonist (GLP-1 RA) peptide, during a late-breaking expert symposium at the 86th Scientific Sessions of the American Diabetes Association (ADA).

The objectives for the phase 2 studies were to identify the right doses for phase 3 and to test escalation schemes. Across both weekly and monthly dosing in participants with obesity or overweight, with and without Type 2 Diabetes (T2D), the data from the phase 2b VESPER-1, 2 and 3 studies provide proof of concept for berobenatide as a potential first-in-class monthly GLP-1 RA peptide that can deliver competitive weight loss; show favorable tolerability for berobenatide, including low gastrointestinal (GI) Adverse Events (AEs) and discontinuations despite rapid dose escalation and no allowed step-down; and highlight the potential for monthly delivery in a patient-friendly presentation with a very low 0.5 mL injection volume that provides convenience and scalability advantages.

Results from a 32-week exploratory extension (Part B) of the phase 2b VESPER-1 study showed a non-placebo-adjusted weight loss of 15.9 percent with no plateau observed at 32 weeks on berobenatide (week 60 of the overall study), in participants who escalated from placebo to 2.4 mg weekly berobenatide. VESPER-1 is evaluating once-weekly berobenatide in adults with obesity or overweight, including Part B to assess the durability of weight loss and the impact of transitioning from once-weekly to less frequent dosing regimens, including once-monthly.

Jim List, MD, PhD, Chief Internal Medicine Officer, Pfizer, said, "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. 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.”

Detailed results from the previously reported phase 2b VESPER-3 study are also being presented today, which is evaluating monthly maintenance dosing of berobenatide in adults with obesity or overweight without T2D. In addition, data from the phase 2b VESPER-2 study, which evaluated weekly dosing of berobenatide in adults with obesity or overweight and T2D, showed dose-dependent reductions from baseline were observed with berobenatide for both body weight and HbA1c. Of note, there was a 2.2 percent reduction in HbA1c achieved with berobenatide 1.6 mg weekly at week 28 (on treatment [efficacy] estimand), compared to a reduction of 0.2 percent in the placebo group.

John B. Buse, MD, PhD, Professor of Medicine, University of North Carolina School of Medicine, Chapel Hill, said, "Weight management is a lifelong commitment, and the barriers to staying on therapy long-term are just as important as the therapy itself. 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."

The VESPER-6 pivotal phase 3 study investigating monthly maintenance dosing for berobenatide in adults with obesity or overweight is open for enrollment, as well as the SOLIS-1 phase 2b study investigating weekly and monthly maintenance dosing of an ultra-long-acting amylin analog (PF'3945) as a monotherapy and in combination with berobenatide.