New Monthly GLP-1 Data Shows Potential in Obesity Management With Monthly Dosing

Pfizer announced positive topline results from its phase 2b VESPER-3 (NCT06973720) study, revealing that its ultra-long-acting injectable glucagon-like peptide-1 (GLP-1) receptor agonist, PF-08653944, achieved robust weight loss with a transition to monthly dosing.¹

This investigational therapy, also known as MET-097i, demonstrated that patients could maintain and even continue weight loss after switching from weekly titration to a monthly maintenance schedule, effectively reducing dosing frequency 4-fold while maintaining efficacy. For the pharmacy community, these results suggest a potential new standard in medication adherence and convenience for patients navigating the chronic management of obesity.

“These topline results from the phase 2b VESPER-3 study reinforce the potential of PF’3944 as a monthly treatment with competitive efficacy,” Jim List, MD, PhD, chief internal medicine officer, said in a news release.

The Study Design and Outcomes of VESPER-3

The VESPER-3 trial is a 64-week, randomized, double-blind, placebo-controlled study targeting adults with obesity or overweight who do not have type 2 diabetes. The methodology utilized a titration phase where participants received weekly subcutaneous injections for the first 12 weeks, followed by a switch to monthly dosing until week 28.^1,2

The study evaluated 4 different dose regimens against a placebo, with approximately 54 participants per arm. The primary outcome of the study was a statistically significant reduction in body weight from randomization to week 28.^1,2

Results showed a mean placebo-adjusted weight loss of up to 12.3% in the medium-dose monthly maintenance arm, and notably, no plateau in weight loss was observed at the 28-week mark. The safety profile remained competitive and consistent with the established GLP-1 RA class, with gastrointestinal adverse effects being predominantly mild or moderate. Across the primary maintenance arms, only 5 participants discontinued treatment due to adverse events during the monthly dosing phase.¹

“Based on the monthly dosing efficacy and tolerability demonstrated in this trial, we remain confident in our plan to include a higher 9.6 mg monthly maintenance dose of PF’3944 in phase 3,” List said in the news release. “With PF-3944 as an anchor of Pfizer’s obesity pipeline, we are positioned to address critical gaps in obesity care and meet the diverse needs of patients.”

The Role of Pharmacists in Obesity Management

As complex therapies like PF-08653944 move toward phase 3 trials, the clinical pharmacist’s role in managing obesity is becoming increasingly critical. Evidence from ambulatory clinic-based settings suggests that pharmacist-led weight loss services significantly improve patient outcomes by addressing the practical barriers to care. Pharmacists are essential for medication selection, providing education on injection devices, managing dose titrations, and offering lifestyle counseling.³

Beyond clinical advice, pharmacists serve as a bridge to medication access, which is often hindered by high costs and the need for complex insurance authorizations. Clinical pharmacists embedded in outpatient clinics have proven successful in helping patients navigate these financial hurdles by utilizing manufacturer copay cards and patient assistance programs.

Furthermore, during periods of nationwide medication shortages, pharmacists are uniquely positioned to provide alternative therapy recommendations and keep patients informed of inventory changes, ensuring continuity of care.

The implementation of specialized pharmacy services has already shown measurable success in achieving a weight loss goal of 5% or more for over 63% of participating patients. By providing frequent follow-up visits—often conducted via telehealth—pharmacists can monitor adverse effects and adherence more closely than traditional provider-only models. This frequent engagement helps mitigate the risk of medication discontinuation due to adverse events, which is a common challenge with GLP-1 therapies.

READ MORE: Obesity Management Resource Center

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REFERENCES

1. Pfizer’s ultra-long-acting injectable GLP-1 RA shows robust and continued weight loss with monthly dosing in phase 2b trial. News release. Pfizer. February 3, 2026. Accessed February 3, 2026. https://www.pfizer.com/news/press-release/press-release-detail/pfizers-ultra-long-acting-injectable-glp-1-ra-shows-robust

2. A phase 2b study to evaluate the efficacy and safety of once-monthly MET097 in adults with obesity or overweight (VESPER-3). ClinicalTrials.gov identification: NCT06973720. February 3, 2026. Accessed February 3, 2026. https://clinicaltrials.gov/study/NCT06973720

3. Schermerhorn S, Aurora J Jr, McElligott M, Siegel RD. Implementation of a pharmacist-led weight loss service to improve medication access and weight loss. J Am Pharm Assoc (2003). 2024;64(4S):102085. doi:10.1016/j.japh.2024.102085