A Study to Learn About Switching to a Monthly Study Medicine Called Berobenatide (PF-08653944) to Help Keep Weight Off in People With Overweight or Obesity

October 9, 2026 updated by: Pfizer

A PHASE 3 STUDY TO EVALUATE THE SWITCH TO MONTHLY BEROBENATIDE FOR MAINTAINING WEIGHT IN ADULTS WHO ARE ON WEEKLY SEMAGLUTIDE OR TIRZEPATIDE (VESPER-SWITCH)

The purpose of this study is to learn about the safety and effectiveness of berobenatide in adults with overweight or obesity who have already lost weight while taking semaglutide or tirzepatide. The study does not include people with diabetes.

Participants will be in the study for about 11 months.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

660

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35294
        • Recruiting
        • University of Alabama at Birmingham
    • California
      • Los Angeles, California, United States, 90017
        • Not yet recruiting
        • Velocity Clinical Research - Los Angeles
      • Santa Ana, California, United States, 92701
        • Not yet recruiting
        • Southern California Clinical Research
      • Walnut Creek, California, United States, 94598
        • Not yet recruiting
        • Diablo Clinical Research, LLC dba Flourish Research
    • Florida
      • Jacksonville, Florida, United States, 32216
        • Not yet recruiting
        • Jacksonville Center for Clinical Research
      • New Port Richey, Florida, United States, 34652
        • Not yet recruiting
        • Suncoast Clinical Research
      • Oviedo, Florida, United States, 32765
        • Not yet recruiting
        • Oviedo Medical Research
    • Kentucky
      • Louisville, Kentucky, United States, 40213
        • Recruiting
        • Monroe Biomedical Research
    • Michigan
      • Flint, Michigan, United States, 48504
        • Not yet recruiting
        • Aa Mrc Llc
    • Mississippi
      • Ridgeland, Mississippi, United States, 39157
        • Not yet recruiting
        • SKY Integrative Medical Center/SKYCRNG
    • Missouri
      • Chesterfield, Missouri, United States, 63005
        • Recruiting
        • Clinical Research Professionals
    • Montana
      • Butte, Montana, United States, 59701
        • Recruiting
        • Mercury Street Medical Group, PLLC
    • North Carolina
      • Monroe, North Carolina, United States, 28112
        • Not yet recruiting
        • Monroe Biomedical Research
      • Wilmington, North Carolina, United States, 28401
        • Not yet recruiting
        • Accellacare - Wilmington
    • Ohio
      • Cincinnati, Ohio, United States, 45219
        • Recruiting
        • Velocity Clinical Research, Mt. Auburn
    • South Carolina
      • Greenville, South Carolina, United States, 29607
        • Not yet recruiting
        • Tribe Clinical Research, LLC

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Aged ≥18 years.
  • Currently taking semaglutide or tirzepatide for obesity management.

Exclusion Criteria:

  • Diagnosis of any form of diabetes.
  • History of acute or chronic pancreatitis.
  • Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN-2).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Active Comparator

Participants will receive Semaglutide or Tirzepatide by Subcutaneous Injection.
Drug: Semaglutide

Participants will receive Semaglutide administered subcutaneously.

Drug: Tirzepatide

Participants will receive Tirzepatide administered subcutaneously.
Experimental: Experimental

Participants will receive Berobenatide by Subcutaneous Injection.
Drug: Berobenatide

Participants will receive berobenatide solution for injection as subcutaneous injection.

Other Names:
  • PF-08653944
  • MET097

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent change from baseline in body weight
Time Frame: Baseline, Week 32
Baseline, Week 32

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from baseline in body weight
Time Frame: Baseline, Week 32
Baseline, Week 32
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Time Frame: Baseline, Week 32
Baseline, Week 32
Number of Participants with Serious adverse events (SAEs)
Time Frame: Baseline, Week 32
Baseline, Week 32
Number of Participants with adverse events leading to discontinuation
Time Frame: Baseline, Week 32
Baseline, Week 32
Number of Participants with Adverse Events of Special Interest (AESIs)
Time Frame: Baseline, Week 32
Baseline, Week 32
Number of Participants with Clinical Laboratory Abnormalities
Time Frame: Baseline, Week 32
Baseline, Week 32

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Pfizer

Investigators

  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 30, 2026

Primary Completion (Estimated)

February 16, 2028

Study Completion (Estimated)

February 16, 2028

Study Registration Dates

First Submitted

September 22, 2026

First Submitted That Met QC Criteria

September 22, 2026

First Posted (Actual)

September 29, 2026

Study Record Updates

Last Update Posted (Actual)

October 15, 2026

Last Update Submitted That Met QC Criteria

October 9, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C6491015

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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