OverweightPhase 1NCT07725809
A Study to Learn How the Study Medicine Called PF-08653945 is Taken up Into the Blood in Adults With Overweight or Obesity
A Phase 1 study testing PF-08653945 in people with Overweight and Obesity, run by Pfizer at 1 site in Belgium.
Trial summary
This study is being done to learn how the study medicine affects the body. It will also assess how safe it is for people who take it. The researchers will use blood tests to measure how much medicine is in the blood. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Overweight, Obesity, Healthy
- What is being tested?
- PF-08653945
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 57 participants
- Where
- 1 siteBelgium
- Study dates
- 23 Jul 2026to 13 Jan 2027
- Phase
- Phase 1
- 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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants 18 years of age or older at Screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and ECGs.
- BMI of 27-45 kg/m2; and a total body weight >50 kg (110 lb).
- For Japanese participants (Optional Cohort 2) only: BMI of 22-45 kg/m2 and a total body weight >50 kg (110 lb). NOTE: Participants enrolling as Japanese must have 4 biological Japanese grandparents who were born in Japan.
Who cannot join
- Pregnant or breastfeeding women, or those planning pregnancy during the study.
- Clinically significant medical conditions including hematologic, renal, endocrine, pulmonary, gastrointestinal (including pancreatitis, gallbladder disease, clinically relevant gastric emptying disorders), cardiovascular, hepatic, psychiatric, neurologic, or severe allergic diseases.
- Personal or first-degree family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN2), or suspected MTC.
- Active or recent suicidal ideation in the past year, suicidal behavior within the past 5 years, or any psychiatric condition that increases risk in the investigator's judgment.
- Clinically significant gastric emptying abnormality or chronically taking drugs that directly affect GI motility.
- Acute gastrointestinal symptoms at screening or Day -1.
- Known hypersensitivity to PF-08653945, amylin or calcitonin agonists, or any excipients.
- Prior participation in any study involving PF-08653945 (formerly MET233) with at least one dose received.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Pfizer Clinical Research Unit - Brussels
Brussels, Bruxelles-capitale, Région de, B-1070
About this study
Official title: A PHASE 1, OPEN-LABEL, RANDOMIZED, SINGLE DOSE, PARALLEL GROUP STUDY TO ASSESS RELATIVE BIOAVAILABILITY OF PF-08653945 WHEN ADMINISTERED ACROSS DIFFERENT INJECTION SITES IN ADULTS WITH OVERWEIGHT OR OBESITY
This study is being done to learn how the study medicine affects the body. It will also assess how safe it is for people who take it. The researchers will use blood tests to measure how much medicine is in the blood.
This study is seeking adults who are:
Read more
- obese or overweight with weight-related health conditions, and
- Meet health and other checks assessed by the study doctor.
The study team will give a single dose of the study treatment at the clinic to the participants. At each study visit, blood samples will be collected and vital signs will be checked. The study team will also ask about any reactions or health changes. Vital signs are basic measurements that show how well the body is working. They help the study team quickly understand a participant's overall health. These usually include body temperature, heart rate, breathing rate, and blood pressure.
The study involves multiple clinic visits at a study site over the length of the study. The information collected will help researchers understand how the study medicine works and whether it is safe.
- Conditions
- Overweight, Obesity, Healthy
- Being tested
- PF-08653945
- Keywords
- obesity, overweight, biological availability, pharmacokinetics
- Medical subject headings
- Overweight, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PF-08653945Drug
Subcutaneous Injection
| Study group | Role | What they receive |
|---|---|---|
| Treatment C (Cohort 1) | Experimental | Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the upper arm. Receives: Drug: PF-08653945 |
| Treatment B (Cohort 1) | Experimental | Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the thigh. Receives: Drug: PF-08653945 |
| Treatment A (Optional Cohort 2) | Experimental | Japanese participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the abdomen. Receives: Drug: PF-08653945 |
| Treatment A (Cohort 1) | Experimental | Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the abdomen. Receives: Drug: PF-08653945 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pharmacokinetics (PK): Area Under the Curve (AUC) of PF-08653945
AUC is a measure of the plasma concentration of the study drug over time. It is used to characterize absorption of the drug.
Measured: Up to 57 days post-dose
Pharmacokinetics (PK): Maximum Observed Concentration (Cmax) of PF-08653945
Cmax refers to the maximum observed serum concentration of the study drug.
Measured: Up to 57 days post-dose
Secondary outcomes (1)
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. Treatment-emergent are events between first dose of study drug and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.
Measured: Up to 57 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2026
- Study start23 Jul 2026
- Primary completion13 Jan 2027 (estimated)
- Study completion13 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for OverweightStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 57 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
- NCT07725809
- Sponsor's protocol ID
- C6501003
- Other IDs
- 2026-526334-67-00
- Status last verified
- Aug 2026
- First submitted
- 21 Jul 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: 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 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 1, OPEN-LABEL, RANDOMIZED, SINGLE DOSE, PARALLEL GROUP STUDY TO ASSESS RELATIVE BIOAVAILABILITY OF PF-08653945 WHEN ADMINISTERED ACROSS DIFFERENT INJECTION SITES IN ADULTS WITH OVERWEIGHT OR OBESITY
- ClinicalTrials.gov ID
- NCT07725809
- Acronym / sponsor ID
- C6501003
- Conditions
- Overweight, Obesity, Healthy
- Keywords
- obesity, overweight, biological availability, pharmacokinetics
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 57 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 23 Jul 2026 (actual)
- Primary completion
- 13 Jan 2027 (estimated)
- Study completion
- 13 Jan 2027 (estimated)
- First posted
- 24 Jul 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.
This study is being done to learn how the study medicine affects the body. It will also assess how safe it is for people who take it. The researchers will use blood tests to measure how much medicine is in the blood.
This study is seeking adults who are:
- obese or overweight with weight-related health conditions, and
- Meet health and other checks assessed by the study doctor.
The study team will give a single dose of the study treatment at the clinic to the participants. At each study visit, blood samples will be collected and vital signs will be checked. The study team will also ask about any reactions or health changes. Vital signs are basic measurements that show how well the body is working. They help the study team quickly understand a participant's overall health. These usually include body temperature, heart rate, breathing rate, and blood pressure.
The study involves multiple clinic visits at a study site over the length of the study. The information collected will help researchers understand how the study medicine works and whether it is safe.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Treatment C (Cohort 1) | Experimental | Drug: PF-08653945Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the upper arm. |
| Treatment B (Cohort 1) | Experimental | Drug: PF-08653945Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the thigh. |
| Treatment A (Optional Cohort 2) | Experimental | Drug: PF-08653945Japanese participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the abdomen. |
| Treatment A (Cohort 1) | Experimental | Drug: PF-08653945Participants will receive a single SC dose of PF 08653945 on Period 1 Day 1 administered to the abdomen. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Participants 18 years of age or older at Screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and ECGs.
- BMI of 27-45 kg/m2; and a total body weight >50 kg (110 lb).
- For Japanese participants (Optional Cohort 2) only: BMI of 22-45 kg/m2 and a total body weight >50 kg (110 lb). NOTE: Participants enrolling as Japanese must have 4 biological Japanese grandparents who were born in Japan.
Key exclusion criteria (8 listed)
- Pregnant or breastfeeding women, or those planning pregnancy during the study.
- Clinically significant medical conditions including hematologic, renal, endocrine, pulmonary, gastrointestinal (including pancreatitis, gallbladder disease, clinically relevant gastric emptying disorders), cardiovascular, hepatic, psychiatric, neurologic, or severe allergic diseases.
- Personal or first-degree family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN2), or suspected MTC.
- Active or recent suicidal ideation in the past year, suicidal behavior within the past 5 years, or any psychiatric condition that increases risk in the investigator's judgment.
- Clinically significant gastric emptying abnormality or chronically taking drugs that directly affect GI motility.
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 |
|---|---|---|
| PF-08653945Subcutaneous Injection | Drug | Treatment A (Cohort 1), Treatment A (Optional Cohort 2), Treatment B (Cohort 1), Treatment C (Cohort 1) |
Primary outcome
Pharmacokinetics (PK): Area Under the Curve (AUC) of PF-08653945
Time frame: Up to 57 days post-dose
AUC is a measure of the plasma concentration of the study drug over time. It is used to characterize absorption of the drug.
Pharmacokinetics (PK): Maximum Observed Concentration (Cmax) of PF-08653945
Time frame: Up to 57 days post-dose
Cmax refers to the maximum observed serum concentration of the study drug.
1 secondary outcome
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to 57 days
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 9 Sep 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. 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
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing PF-08653945 in people with Overweight and Obesity, run by Pfizer at 1 site in Belgium.
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 3 inclusion and 8 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 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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?
Pharmacokinetics (PK): Area Under the Curve (AUC) of PF-08653945 (time frame: Up to 57 days post-dose). The study lists 2 primary outcomes in all. 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 9 Sep 2026.