A Phase 2 interventional study of PF-08653945 and PF-08653944 in Overweight, Obesity and Overweight and/or Obesity, sponsored by Pfizer. Active, not recruiting at 63 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Pfizer · Phase 2, Interventional, and Treatment
This study is being done to learn about the safety and effects of the study drugs, PF-08653945 and PF-08653944, when given alone or together for weight loss, compared to a placebo (a dummy drug that has no active ingredient in it).
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 940 is above the median of 67 across 9,006 interventional studies indexed under Obesity.
Browse Obesity studies →Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Compared within Obesity, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Overweight. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Eligible participants for this study include:
Exclusion Criteria:
Participants who are not eligible include those with diabetes mellitus, a body weight change of >5% or use of weight loss medications in the 12 weeks prior to screening, a history of or plan for surgical treatment for obesity, and those who are unable or unwilling to comply with requirements or are pregnant or lactating.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive subcutaneous injections of PF-08653945 or placebo.
Drug: PF-08653945 · Drug: Placebo
Participants receive subcutaneous injections of PF-08653945 + PF-08653944 or placebo.
Drug: PF-08653945 · Drug: PF-08653944 · Drug: Placebo
Participants receive subcutaneous injections of PF-08653945 + PF-08653944 , PF-08653944 , or placebo.
Drug: PF-08653945 · Drug: PF-08653944 · Drug: Placebo
Subcutaneous Injection
Subcutaneous Injection
Subcutaneous Injection
Percent change from baseline in body weight
Time frame: Baseline (Week 0) to Week 48
Percent change from baseline in body weight
Time frame: Baseline (Week 0) to Week 60
Change from baseline in body weight
Time frame: Baseline (Week 0) to Week 48 and Week 60
Percentage of participants who achieve ≥5% of body weight reduction from baseline
Time frame: Baseline (Week 0) to Week 48 and Week 60
Percentage of participants who achieve ≥10% of body weight reduction from baseline
Time frame: Baseline (Week 0) to Week 48 and Week 60
Percentage of participants who achieve ≥15% of body weight reduction from baseline
Time frame: Baseline (Week 0) to Week 48 and Week 60
Percentage of participants who achieve ≥20% of body weight reduction from baseline
Time frame: Baseline (Week 0) to Week 48 and Week 60
Percentage of participants who achieve ≥25% of body weight reduction from baseline
Time frame: Baseline (Week 0) to Week 48 and Week 60
Number of participants with treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)
Time frame: Up to Week 70
Plan to share: 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.
Data sharing details ↗ · www.pfizer.com
Started May 2026 (actual). Primary completion is estimated for Aug 2027, 14 months after the start.
Of 176 industry-sponsored phase 2 interventional studies under Obesity, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 18. This study's planned 14 months is above that.
Counting every sponsor, half of 308 studies reached it within 16 months; a quarter within 10 and three quarters within 35.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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