Efficacy and Safety of KAI-9531 Administered Once Weekly Compared With Semaglutide and Placebo in Participants Living With Obesity Who Do Not Have Diabetes

April 29, 2026 updated by: Kailera

A Phase 3, Randomized, Active- and Placebo-Controlled, Partially-Blinded Study to Compare the Efficacy and Safety of KAI-9531 Administered Once Weekly Versus Semaglutide and Placebo in Participants Living With Obesity Who Do Not Have Diabetes

The primary objective of this study is to demonstrate that KAI-9531 subcutaneous (SC) injection once weekly is superior to semaglutide SC once weekly and to placebo SC once weekly on percent change in body weight.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

1200

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

  • Australia
    • Australian Capital Territory
      • Bruce, Australian Capital Territory, Australia, 2617
        • Recruiting
        • Kailera Clinical Site
    • New South Wales
      • Blacktown, New South Wales, Australia, 2148
        • Recruiting
        • Kailera Clinical Site
      • Kanwal, New South Wales, Australia, 2259
        • Recruiting
        • Kailera Clinical Site
    • Queensland
      • Herston, Queensland, Australia, 4006
        • Recruiting
        • Kailera Clinical Site
      • Morayfield, Queensland, Australia, 4506
        • Recruiting
        • Kailera Clinical Site
      • South Brisbane, Queensland, Australia, 4101
        • Recruiting
        • Kailera Clinical Site
    • Victoria
      • Camberwell, Victoria, Australia, 3124
        • Recruiting
        • Kailera Clinical Site
  • United States
    • Arizona
      • Glendale, Arizona, United States, 85308
        • Recruiting
        • Kailera Clinical Site
      • Phoenix, Arizona, United States, 85012
        • Recruiting
        • Kailera Clinical Site
    • Arkansas
      • Little Rock, Arkansas, United States, 72205
        • Recruiting
        • Kailera Clinical Site
    • California
      • Northridge, California, United States, 91325
        • Recruiting
        • Kailera Clinical Site
      • Oceanside, California, United States, 92058
        • Recruiting
        • Kailera Clinical Site
    • Connecticut
      • Hamden, Connecticut, United States, 06517
        • Recruiting
        • Kailera Clinical Site
      • Stamford, Connecticut, United States, 06905
        • Recruiting
        • Kailera Clinical Site
    • Florida
      • Orange City, Florida, United States, 32763
        • Recruiting
        • Kailera Clinical Site
    • Georgia
      • Albany, Georgia, United States, 31707
        • Recruiting
        • Kailera Clinical Site
    • Illinois
      • Chicago, Illinois, United States, 60640
        • Recruiting
        • Kailera Clinical Site
    • Kansas
      • Newton, Kansas, United States, 67114
        • Recruiting
        • Kailera Clinical Site
    • Louisiana
      • Shreveport, Louisiana, United States, 71105
        • Recruiting
        • Kailera Clinical Site
    • Michigan
      • Farmington Hills, Michigan, United States, 48334
        • Recruiting
        • Kailera Clinical Site
    • Montana
      • Missoula, Montana, United States, 59804
        • Recruiting
        • Kailera Clinical Site
    • Nevada
      • Las Vegas, Nevada, United States, 89148
        • Recruiting
        • Kailera Clinical Site
    • New York
      • Albany, New York, United States, 12203
        • Recruiting
        • Kailera Clinical Site
    • North Carolina
      • Morehead City, North Carolina, United States, 28557
        • Recruiting
        • Kailera Clinical Site
    • Oklahoma
      • Norman, Oklahoma, United States, 73069
        • Recruiting
        • Kailera Clinical Site
    • Rhode Island
      • East Greenwich, Rhode Island, United States, 02818
        • Recruiting
        • Kailera Clinical Site
    • South Carolina
      • North Charleston, South Carolina, United States, 29405
        • Recruiting
        • Kailera Clinical Site
      • Spartanburg, South Carolina, United States, 29303
        • Recruiting
        • Kailera Clinical Site
    • Texas
      • Brownsville, Texas, United States, 78526
        • Recruiting
        • Kailera Clinical Site
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • Kailera Clinical Site
    • Virginia
      • Manassas, Virginia, United States, 20110
        • Recruiting
        • Kailera Clinical Site
      • Richmond, Virginia, United States, 23236
        • Recruiting
        • Kailera Clinical Site

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

Key Inclusion Criteria:

  • BMI ≥35 kilograms per square meter (kg/m^2).
  • History of at least 1 self-reported unsuccessful effort to lose weight with diet and exercise within the prior 6 months.

Key Exclusion Criteria:

  • Current diagnosis or history of diabetes mellitus.
  • Started medications within 3 months prior to Screening that may cause significant weight gain, including, but not limited to, tricyclic antidepressants, atypical antipsychotics, and mood stabilizers.
  • Unstable weight defined as self-reported change in body weight exceeding 5% within the 3 months prior to Screening.
  • Family or personal history of multiple endocrine neoplasia Type 2 or medullary thyroid cancer.
  • Uncontrolled hypertension or unstable cardiovascular disease.
  • History of chronic or acute pancreatitis.
  • Known clinically significant gastric-emptying abnormality or chronic treatment with medications that directly affect gastrointestinal motility.
  • History of suicide attempt.
  • History of significant active or unstable Major Depressive Disorder (MDD) or other severe psychiatric disorder.
  • Received treatment with semaglutide, tirzepatide, glucagon-like peptide-1 receptor (GLP-1R) agonist, GLP-1/glucose-dependent insulinotropic polypeptide (GIP), or glucagon receptor agonist within 3 months prior to Screening.

Note: Additional inclusion/exclusion criteria may apply, per protocol.

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: KAI-9531: Dose 1
Participants will receive Dose 1 of KAI-9531 once weekly.
Drug: KAI-9531
SC Injection
Placebo Comparator: Placebo
Participants will receive placebo matched to KAI-9531 once weekly.
Drug: Placebo
SC Injection
Experimental: KAI-9531: Dose 2
Participants will receive Dose 2 of KAI-9531 once weekly.
Drug: KAI-9531
SC Injection
Active Comparator: Semaglutide
Participants will receive semaglutide once weekly.
Drug: Semaglutide
SC Injection
Other Names:
  • Wegovy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent Change From Baseline in Body Weight at Week 76
Time Frame: Baseline, Week 76
Baseline, Week 76

Secondary Outcome Measures

Outcome Measure
Time Frame
Percentage of Participants with ≥10%, ≥15%, ≥20% and ≥25% Reduction in Body Weight
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Waist Circumference
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Absolute Body Weight
Time Frame: Baseline, Week 76
Baseline, Week 76
Percentage of Participants with ≥5% Reduction in Body Weight
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Systolic Blood Pressure (SBP)
Time Frame: Baseline, Week 76
Baseline, Week 76
Percent Change From Baseline in Fasting Triglycerides
Time Frame: Baseline, Week 76
Baseline, Week 76
Percent Change From Baseline in Fasting High-density Lipoprotein (HDL)-cholesterol
Time Frame: Baseline, Week 76
Baseline, Week 76
Percent Change From Baseline in Fasting Non-HDL-cholesterol
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT) Physical Function Composite Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Percentage of Participants with ≥30% Reduction in Body Weight
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Body Mass Index (BMI)
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Control of Eating Questionnaire (CoEQ) Craving Control Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Positive Mood Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Craving for Sweets Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Craving for Savory Food Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Hunger Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Satiety Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in CoEQ Combined Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Change From Baseline in Food Noise Questionnaire (FNQ) Score
Time Frame: Baseline, Week 76
Baseline, Week 76
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Time Frame: Day 1 up to Week 80
Day 1 up to Week 80
Number of Participants With Anti-drug Antibodies (ADAs)
Time Frame: Up to Week 80
Up to Week 80
Number of Participants With Neutralizing Antibodies (Nabs)
Time Frame: Up to Week 80
Up to Week 80
Plasma Concentrations of KAI-9531
Time Frame: Up to Week 76
Up to Week 76

Collaborators and Investigators

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

Sponsor

Kailera

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)

December 30, 2025

Primary Completion (Estimated)

March 20, 2028

Study Completion (Estimated)

April 17, 2028

Study Registration Dates

First Submitted

December 9, 2025

First Submitted That Met QC Criteria

December 9, 2025

First Posted (Actual)

December 16, 2025

Study Record Updates

Last Update Posted (Actual)

April 30, 2026

Last Update Submitted That Met QC Criteria

April 29, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • K9531-3107
  • 2025-523511-11-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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