Efficacy and Safety of Ribupatide (KAI-9531) Administered Once Weekly in Participants Living With Obesity Who Do Not Have Diabetes

May 27, 2026 updated by: Kailera

A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of KAI-9531 Administered Once Weekly in Participants Living With Obesity Who Do Not Have Diabetes

The primary objective of this study is to determine the effects of ribupatide administered by subcutaneous (SC) injection once weekly compared to placebo on percent change in body weight.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

250

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 Locations

  • United States
    • Arizona
      • Mesa, Arizona, United States, 85213
        • Kailera Clinical Site
      • Sun City West, Arizona, United States, 85375
        • Kailera Clinical Site
    • California
      • Irvine, California, United States, 92614
        • Kailera Clinical Site
      • Lake Forest, California, United States, 92630
        • Kailera Clinical Site
      • Lomita, California, United States, 90717
        • Kailera Clinical Site
      • Long Beach, California, United States, 90815
        • Kailera Clinical Site
      • Montclair, California, United States, 91763
        • Kailera Clinical Site
      • Rolling Hills Estates, California, United States, 90274
        • Kailera Clinical Site
      • San Diego, California, United States, 92103
        • Kailera Clinical Site
      • Santa Ana, California, United States, 92704
        • Kailera Clinical Site
      • Van Nuys, California, United States, 91405
        • Kailera Clinical Site
    • Florida
      • DeLand, Florida, United States, 32720
        • Kailera Clinical Site
      • Orlando, Florida, United States, 32801
        • Kailera Clinical Site
      • Orlando, Florida, United States, 32803
        • Kailera Clinical Site
      • The Villages, Florida, United States, 32162
        • Kailera Clinical Site
    • Georgia
      • Decatur, Georgia, United States, 30030
        • Kailera Clinical Site
      • Woodstock, Georgia, United States, 30189
        • Kailera Clinical Site
    • Illinois
      • Morton, Illinois, United States, 61550
        • Kailera Clinical Site
    • Indiana
      • Indianapolis, Indiana, United States, 46254
        • Kailera Clinical Site
    • Kentucky
      • Louisville, Kentucky, United States, 40213
        • Kailera Clinical Site
    • Maryland
      • Rockville, Maryland, United States, 20852
        • Kailera Clinical Site
    • Missouri
      • St Louis, Missouri, United States, 63141
        • Kailera Clinical Site
    • Nebraska
      • Lincoln, Nebraska, United States, 68516
        • Kailera Clinical Site
      • Omaha, Nebraska, United States, 68144
        • Kailera Clinical Site
    • New York
      • East Syracuse, New York, United States, 13057
        • Kailera Clinical Site
    • North Carolina
      • Greensboro, North Carolina, United States, 27405
        • Kailera Clinical Site
      • Monroe, North Carolina, United States, 28112
        • Kailera Clinical Site
      • Raleigh, North Carolina, United States, 27612
        • Kailera Clinical Site
    • South Carolina
      • Greenville, South Carolina, United States, 29607
        • Kailera Clinical Site
      • Myrtle Beach, South Carolina, United States, 29572
        • Kailera Clinical Site
    • Tennessee
      • Knoxville, Tennessee, United States, 37909
        • Kailera Clinical Site
      • Memphis, Tennessee, United States, 38119
        • Kailera Clinical Site
    • Texas
      • Garland, Texas, United States, 75043
        • Kailera Clinical Site
      • San Antonio, Texas, United States, 78215
        • Kailera Clinical Site
    • Virginia
      • Winchester, Virginia, United States, 22601
        • 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 meter squared (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, including type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM), history of diabetic ketoacidosis, or hyperosmolar state/coma.
  • 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 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 within 2 years prior to Screening.
  • Received treatment with semaglutide, tirzepatide, glucagon-like peptide-1 receptor (GLP-1R) agonist, GLP-1R/glucose-dependent insulinotropic polypeptide receptor (GIPR), 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: Ribupatide: Dose 1
Participants will receive Dose 1 of ribupatide once weekly.
Drug: Ribupatide
SC Injection
Other Names:
  • KAI-9531
Experimental: Ribupatide: Dose 2
Participants will receive Dose 2 of ribupatide once weekly.
Drug: Ribupatide
SC Injection
Other Names:
  • KAI-9531
Experimental: Ribupatide: Dose 3
Participants will receive Dose 3 of ribupatide once weekly.
Drug: Ribupatide
SC Injection
Other Names:
  • KAI-9531
Experimental: Ribupatide: Dose 4
Participants will receive Dose 4 of ribupatide once weekly.
Drug: Ribupatide
SC Injection
Other Names:
  • KAI-9531
Placebo Comparator: Placebo
Participants will receive placebo matched to ribupatide once weekly.
Drug: Placebo
SC Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent Change From Baseline in Body Weight at Week 48
Time Frame: Baseline, Week 48
Baseline, Week 48

Secondary Outcome Measures

Outcome Measure
Time Frame
Change From Baseline in Body Mass Index (BMI)
Time Frame: Baseline, Week 48
Baseline, Week 48
Change From Baseline in Waist Circumference
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent of Participants with ≥5%, ≥10%, ≥15%, ≥20% and ≥25% Reduction From Baseline in Body Weight
Time Frame: Baseline, Week 48
Baseline, Week 48
Change From Baseline in Absolute Body Weight
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Triglycerides
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting High-density Lipoprotein (HDL)-cholesterol
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Non-HDL-cholesterol
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Total Cholesterol
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Low-density Lipoprotein (LDL)-cholesterol
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Very Low-density Lipoprotein (VLDL)-cholesterol
Time Frame: Baseline, Week 48
Baseline, Week 48
Percent Change From Baseline in Fasting Insulin
Time Frame: Baseline, Week 48
Baseline, Week 48
Change From Baseline in Fasting Blood Glucose
Time Frame: Baseline, Week 48
Baseline, Week 48
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Time Frame: Day 1 up to Week 52
Day 1 up to Week 52
Number of Participants With Anti-drug Antibodies (ADAs)
Time Frame: Day 1 up to Week 52
Day 1 up to Week 52
Number of Participants With Neutralizing Antibodies (NAbs)
Time Frame: Day 1 up to Week 52
Day 1 up to Week 52
Plasma Concentrations of Ribupatide
Time Frame: Day 1 up to Week 52
Day 1 up to Week 52

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)

March 4, 2026

Primary Completion (Estimated)

May 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

March 3, 2026

First Submitted That Met QC Criteria

March 3, 2026

First Posted (Actual)

March 9, 2026

Study Record Updates

Last Update Posted (Actual)

May 29, 2026

Last Update Submitted That Met QC Criteria

May 27, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • K9531-2110

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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