A Study of PF-08653945 and PF-08653944 in Adults With Overweight or Obesity (SOLIS-1) (SOLIS-1)

July 21, 2026 updated by: Pfizer

A PHASE 2B, RANDOMIZED, PLACEBO-CONTROLLED, DOUBLE-BLIND, DOSE RANGING, DOSE-FINDING, UMBRELLA STUDY TO EVALUATE EFFICACY AND SAFETY OF PF-08653945 AND PF-08653944, ALONE OR IN COMBINATION, IN ADULTS WITH OVERWEIGHT OR OBESITY (SOLIS-1)

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).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

872

Phase

  • Phase 2

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

  • Canada
    • Nova Scotia
      • Bridgewater, Nova Scotia, Canada, B4V 3N2
        • Recruiting
        • Viable Clinical Research Corporation
    • Ontario
      • Brampton, Ontario, Canada, L6T 0G1
        • Recruiting
        • Aggarwal and Associates Limited
      • Etobicoke, Ontario, Canada, M9R 4E1
        • Recruiting
        • Centricity Research Etobicoke Endocrinology
      • London, Ontario, Canada, N5W 6A2
        • Recruiting
        • Milestone Research Inc.
      • Sarnia, Ontario, Canada, N7T 4X3
        • Recruiting
        • Bluewater Clinical Research Group Inc.
      • Toronto, Ontario, Canada, M9V 4B4
        • Recruiting
        • Dr. Anil K. Gupta Medicine Professional Corporation
      • Toronto, Ontario, Canada, M9W 4L6
        • Recruiting
        • Centricity Research Toronto Manna Multispecialty
    • Quebec
      • Chicoutimi, Quebec, Canada, G7H 7K9
        • Not yet recruiting
        • Ecogene-21
      • Mirabel, Quebec, Canada, J7J 2K8
        • Not yet recruiting
        • Centricity Research Mirabel Multispecialty
      • Montreal, Quebec, Canada, H1Y 3H5
        • Not yet recruiting
        • Recherche GCP Research
  • United States
    • Arizona
      • Chandler, Arizona, United States, 85225
        • Recruiting
        • Arizona Clinical Trials-Chandler
      • Sun City West, Arizona, United States, 85375
        • Recruiting
        • Clinical Research Institute of Arizona
      • Tucson, Arizona, United States, 85711
        • Recruiting
        • Arizona Clinical Trials (ACT) - Tucson
    • California
      • Canoga Park, California, United States, 91304
        • Recruiting
        • San Fernando Valley Health Institute
      • Fountain Valley, California, United States, 92708
        • Recruiting
        • Ark Clinical Research
      • Garden Grove, California, United States, 92840
        • Recruiting
        • Paragon Rx Clinical
      • Lomita, California, United States, 90717
        • Recruiting
        • Torrance Clinical Research Institute, Inc.
      • Long Beach, California, United States, 90815
        • Recruiting
        • Ark Clinical Research
      • Los Alamitos, California, United States, 90720
        • Recruiting
        • Collaborative Neuroscience Research, LLC
      • Modesto, California, United States, 95355
        • Recruiting
        • Paradigm Clinical Research-Modesto
      • San Diego, California, United States, 92108
        • Recruiting
        • Paradigm Clinical Research Centers, LLC
      • Tustin, California, United States, 92780
        • Recruiting
        • University Clinical Investigators, Incorporated
      • Walnut Creek, California, United States, 94598
        • Recruiting
        • Diablo Clinical Research, LLC dba Flourish Research
    • Florida
      • Hialeah, Florida, United States, 33012
        • Recruiting
        • AGA Clinical Trials
      • Jacksonville, Florida, United States, 32205
        • Recruiting
        • Westside Center for Clinical Research
      • Miami, Florida, United States, 33165
        • Recruiting
        • New Horizon Research Center
      • Orlando, Florida, United States, 32803
        • Recruiting
        • Charter Research
    • Georgia
      • Atlanta, Georgia, United States, 30318
        • Recruiting
        • Atlanta Diabetes Associates
      • Stockbridge, Georgia, United States, 30281
        • Recruiting
        • Clinical Research Atlanta
    • Illinois
      • Morton, Illinois, United States, 61550
        • Recruiting
        • Koch Family Medicine Clinical Research/Elite Research Network
      • Naperville, Illinois, United States, 60540
        • Recruiting
        • Bioluminux Clinical Research Illinois
    • Kansas
      • Lenexa, Kansas, United States, 66219
        • Recruiting
        • Johnson County Clinical Trials
    • Louisiana
      • Mandeville, Louisiana, United States, 70471
        • Recruiting
        • Delricht Research
      • Prairieville, Louisiana, United States, 70769
        • Recruiting
        • Delricht Research
    • Maryland
      • Lutherville, Maryland, United States, 21093
        • Recruiting
        • Patient First Clinical Trials (PFCTRIALS)
    • Missouri
      • Springfield, Missouri, United States, 65807
        • Recruiting
        • Delricht Research
    • Montana
      • Butte, Montana, United States, 59701
        • Recruiting
        • Mercury Street Medical Group, PLLC
    • Nevada
      • Las Vegas, Nevada, United States, 89119
        • Recruiting
        • AB Clinical Trials
      • Las Vegas, Nevada, United States, 89128
        • Recruiting
        • Palm Research Center
      • Las Vegas, Nevada, United States, 89109
        • Recruiting
        • Alliance Clinical Research Las Vegas (Excel Clinical Research)
    • New Jersey
      • Hamilton, New Jersey, United States, 08690
        • Recruiting
        • Bioluminux Clinical Research
    • North Carolina
      • Charlotte, North Carolina, United States, 28210
        • Recruiting
        • Delricht Research
      • Monroe, North Carolina, United States, 28112
        • Recruiting
        • Monroe Biomedical Research
      • Statesville, North Carolina, United States, 28625
        • Recruiting
        • Piedmont Healthcare
      • Wilmington, North Carolina, United States, 28401
        • Recruiting
        • Accellacare - Wilmington
    • Oklahoma
      • Edmond, Oklahoma, United States, 73013
        • Recruiting
        • Tekton Research, LLC.
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15236
        • Recruiting
        • Preferred Primary Care Physicians
      • Uniontown, Pennsylvania, United States, 15401
        • Recruiting
        • Preferred Primary Care Physicians
      • Uniontown, Pennsylvania, United States, 15401
        • Recruiting
        • Preferred Primary Care Physicians, Inc.
    • South Carolina
      • Myrtle Beach, South Carolina, United States, 29572
        • Recruiting
        • TMA Headlands LLC (d/b/a Trial Management Associates)
    • Tennessee
      • Hendersonville, Tennessee, United States, 37075
        • Recruiting
        • Delricht Research
    • Texas
      • Euless, Texas, United States, 76040
        • Recruiting
        • Cedar Health Research - Euless
      • Houston, Texas, United States, 77040
        • Recruiting
        • JCCT-JUNO NW Houston
      • Kingwood, Texas, United States, 77339
        • Recruiting
        • Activian Clinical Research
      • Plano, Texas, United States, 75093
        • Recruiting
        • 3A Research
      • Prosper, Texas, United States, 75078
        • Recruiting
        • DelRicht Research @ Zomnir Family Medicine
      • San Antonio, Texas, United States, 78217
        • Recruiting
        • Worldwide Clinical Trials
      • San Antonio, Texas, United States, 78258
        • Recruiting
        • Tekton Research, LLC.
      • Shavano Park, Texas, United States, 78231
        • Recruiting
        • Consano Clinical Research, LLC
      • Tomball, Texas, United States, 77375
        • Recruiting
        • DM Clinical Research
    • Utah
      • Salt Lake City, Utah, United States, 84107
        • Recruiting
        • Wasatch Clinical Research, LLC
      • Salt Lake City, Utah, United States, 84102
        • Recruiting
        • Alpine Medical Group
    • Virginia
      • Arlington, Virginia, United States, 22206
        • Recruiting
        • Washington Center for Weight Management and Research
      • Manassas, Virginia, United States, 20110
        • Recruiting
        • Manassas Clinical Research Center
      • Vienna, Virginia, United States, 22182
        • Recruiting
        • Delricht Research

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Eligible participants for this study include:

  • adults aged 18 years or older with
  • obesity (BMI of 30.0 kg/m2 to 50.0 kg/m2) or with
  • overweight (BMI of 27.0 kg/m2 to <30.0 kg/m2) who also have at least 1 prespecified weight-related comorbidity (hypertension, dyslipidemia, cardiovascular disease, or obstructive sleep apnea), at the screening visit.

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 contraceptive requirements or are pregnant or lactating.

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Cohort 1
Participants receive subcutaneous injections of PF-08653945 or placebo.
Drug: Placebo
Subcutaneous Injection
Drug: PF-08653945
Subcutaneous Injection
Experimental: Cohort 2
Participants receive subcutaneous injections of PF-08653945 + PF-08653944 or placebo.
Drug: Placebo
Subcutaneous Injection
Drug: PF-08653944
Subcutaneous Injection
Drug: PF-08653945
Subcutaneous Injection
Experimental: Cohort 3
Participants receive subcutaneous injections of PF-08653945 + PF-08653944 , PF-08653944 , or placebo.
Drug: Placebo
Subcutaneous Injection
Drug: PF-08653944
Subcutaneous Injection
Drug: PF-08653945
Subcutaneous Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent change from baseline in body weight
Time Frame: Baseline (Week 0) to Week 48
Baseline (Week 0) to Week 48

Secondary Outcome Measures

Outcome Measure
Time Frame
Percent change from baseline in body weight
Time Frame: Baseline (Week 0) to Week 60
Baseline (Week 0) to Week 60
Change from baseline in body weight
Time Frame: Baseline (Week 0) to Week 48 and Week 60
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
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
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
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
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
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
Up to Week 70

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)

May 11, 2026

Primary Completion (Estimated)

August 4, 2027

Study Completion (Estimated)

January 5, 2028

Study Registration Dates

First Submitted

May 4, 2026

First Submitted That Met QC Criteria

May 4, 2026

First Posted (Actual)

May 8, 2026

Study Record Updates

Last Update Posted (Actual)

July 22, 2026

Last Update Submitted That Met QC Criteria

July 21, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C6511002
  • SOLIS-1 (Other Identifier: Alias Study Number)

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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