ObesityPhase 3NCT07845500
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
A Phase 3 study testing Semaglutide, Berobenatide and Tirzepatide in people with Obesity and Overweight and/or Obesity, run by Pfizer at 16 sites in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obesity, Overweight and/or Obesity, Overweight
- What is being tested?
- Semaglutide, Berobenatide and Tirzepatide
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 660 participants
- Where
- 16 sitesUnited States
- Study dates
- 30 Sep 2026to 16 Feb 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged ≥18 years.
- Currently taking semaglutide or tirzepatide for obesity management.
Who cannot join
- 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).
Trial locations and contacts
16 sites in 1 country. Contact the study team or a site near you to ask about taking part.
16 sites in 1 country
United States16 sites, 16 recruiting
- Recruiting
University of Alabama at Birmingham
Birmingham, Alabama, 35294
- Recruiting
Mercury Street Medical Group, PLLC
Butte, Montana, 59701
- Recruiting
Clinical Research Professionals
Chesterfield, Missouri, 63005
- Recruiting
Velocity Clinical Research, Mt. Auburn
Cincinnati, Ohio, 45219
- Not yet recruiting
Aa Mrc Llc
Flint, Michigan, 48504
- Not yet recruiting
Tribe Clinical Research, LLC
Greenville, South Carolina, 29607
- Not yet recruiting
Jacksonville Center for Clinical Research
Jacksonville, Florida, 32216
- Not yet recruiting
Velocity Clinical Research - Los Angeles
Los Angeles, California, 90017
- Recruiting
Monroe Biomedical Research
Louisville, Kentucky, 40213
- Not yet recruiting
Monroe Biomedical Research
Monroe, North Carolina, 28112
- Not yet recruiting
Suncoast Clinical Research
New Port Richey, Florida, 34652
- Not yet recruiting
Oviedo Medical Research
Oviedo, Florida, 32765
- Not yet recruiting
SKY Integrative Medical Center/SKYCRNG
Ridgeland, Mississippi, 39157
- Not yet recruiting
Southern California Clinical Research
Santa Ana, California, 92701
- Not yet recruiting
Diablo Clinical Research, LLC dba Flourish Research
Walnut Creek, California, 94598
- Not yet recruiting
Accellacare - Wilmington
Wilmington, North Carolina, 28401
About this study
Official title: 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.
- Conditions
- Obesity, Overweight and/or Obesity, Overweight, Treatment Of Obesity
- Being tested
- Semaglutide, Berobenatide, Tirzepatide
- Keywords
- nutrition disorder
- Medical subject headings
- Obesity, Overweight, Nutrition Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SemaglutideDrug
Participants will receive Semaglutide administered subcutaneously.
BerobenatideDrug
Also called MET097, PF-08653944
Participants will receive berobenatide solution for injection as subcutaneous injection.
TirzepatideDrug
Participants will receive Tirzepatide administered subcutaneously.
| Study group | Role | What they receive |
|---|---|---|
| Active Comparator | Active comparator | Participants will receive Semaglutide or Tirzepatide by Subcutaneous Injection. Receives: Drug: Semaglutide; Drug: Tirzepatide |
| Experimental | Experimental | Participants will receive Berobenatide by Subcutaneous Injection. Receives: Drug: Berobenatide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent change from baseline in body weight
Measured: Baseline, Week 32
Secondary outcomes (6)
Change from baseline in body weight
Measured: Baseline, Week 32
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Measured: Baseline, Week 32
Number of Participants with Serious adverse events (SAEs)
Measured: Baseline, Week 32
Number of Participants with adverse events leading to discontinuation
Measured: Baseline, Week 32
Number of Participants with Adverse Events of Special Interest (AESIs)
Measured: Baseline, Week 32
Number of Participants with Clinical Laboratory Abnormalities
Measured: Baseline, Week 32
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start30 Sep 2026
- Primary completion16 Feb 2028 (estimated)
- Study completion16 Feb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 660 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07845500
- Sponsor's protocol ID
- C6491015
- Status last verified
- Oct 2026
- First submitted
- 22 Sep 2026
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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.
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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)
- ClinicalTrials.gov ID
- NCT07845500
- Acronym / sponsor ID
- C6491015
- Conditions
- Obesity, Overweight and/or Obesity, Overweight, Treatment Of Obesity
- Keywords
- nutrition disorder
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 660 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 30 Sep 2026 (actual)
- Primary completion
- 16 Feb 2028 (estimated)
- Study completion
- 16 Feb 2028 (estimated)
- First posted
- 29 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Active Comparator | Active comparator | Drug: Semaglutide, Drug: TirzepatideParticipants will receive Semaglutide or Tirzepatide by Subcutaneous Injection. |
| Experimental | Experimental | Drug: BerobenatideParticipants will receive Berobenatide by Subcutaneous Injection. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Aged ≥18 years.
- Currently taking semaglutide or tirzepatide for obesity management.
Key exclusion criteria (3 listed)
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SemaglutideParticipants will receive Semaglutide administered subcutaneously. | Drug | Active Comparator |
| BerobenatideAlso: MET097, PF-08653944Participants will receive berobenatide solution for injection as subcutaneous injection. | Drug | Experimental |
| TirzepatideParticipants will receive Tirzepatide administered subcutaneously. | Drug | Active Comparator |
Primary outcome
Percent change from baseline in body weight
Time frame: Baseline, Week 32
6 secondary outcomes
Change from baseline in body weight
Time frame: Baseline, Week 32
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Time frame: Baseline, Week 32
Number of Participants with Serious adverse events (SAEs)
Time frame: Baseline, Week 32
Number of Participants with adverse events leading to discontinuation
Time frame: Baseline, Week 32
Number of Participants with Adverse Events of Special Interest (AESIs)
Time frame: Baseline, Week 32
Number of Participants with Clinical Laboratory Abnormalities
Time frame: Baseline, Week 32
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Oct 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Pfizer CT.gov Call Center study director
Pfizer
16 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Semaglutide, Berobenatide and Tirzepatide in people with Obesity and Overweight and/or Obesity, run by Pfizer at 16 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 16 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percent change from baseline in body weight (time frame: Baseline, Week 32). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.