A Study of Retatrutide (LY3437943) Once Weekly in Participants Who Have Obesity or Overweight and Osteoarthritis of the Knee (TRIUMPH-4)

January 20, 2026 updated by: Eli Lilly and Company

A Phase 3 Study to Investigate the Efficacy and Safety of LY3437943 Once Weekly in Participants Who Have Obesity or Overweight and Osteoarthritis of the Knee: A Randomized, Double-Blind, Placebo-Controlled Trial

The main purpose of this study is to evaluate the safety and efficacy of retatrutide once-weekly in participants who have obesity or are overweight and have osteoarthritis (OA) of the knee. The study will lasts about 77 weeks.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

445

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 Locations

  • Australia
    • Australian Capital Territory
      • Bruce, Australian Capital Territory, Australia, 2617
        • Paratus Clinical Research Canberra
    • New South Wales
      • Blacktown, New South Wales, Australia, 2148
        • Paratus Clinical Research Western Sydney
      • Botany, New South Wales, Australia, 2019
        • Emeritus Research
    • Queensland
      • Brisbane, Queensland, Australia, 4029
        • Royal Brisbane and Women's Hospital
      • Brisbane, Queensland, Australia, 4064
        • Core Research Group
      • Maroochydore, Queensland, Australia, 4558
        • CDH Research Institute
    • Victoria
      • Camberwell, Victoria, Australia, 3124
        • Emeritus Research
      • Geelong, Victoria, Australia, 3220
        • Barwon Health
  • Canada
      • Québec, Canada, G3K 2P8
        • ALPHA Recherche Clinique
      • Québec, Canada, G2J 0C4
        • ALPHA Recherche Clinique
    • Alberta
      • Calgary, Alberta, Canada, T2V 4J2
        • C-health Research
    • Newfoundland and Labrador
      • St. John's, Newfoundland and Labrador, Canada, A1B 3V6
        • Eastern Health - General Hospital
    • Nova Scotia
      • Bridgewater, Nova Scotia, Canada, B4V 3N2
        • Viable Clinical Research
    • Ontario
      • Hamilton, Ontario, Canada, L8L 5G8
        • Wharton Medical Clinic
      • Sarnia, Ontario, Canada, N7T 4X3
        • Bluewater Clinical Research Group Inc.
      • Scarborough Village, Ontario, Canada, M1P 2T7
        • Viable Clinical Research
      • Stouffville, Ontario, Canada, L4A 1H2
        • Stouffville Medical Research Institute Inc.
      • Toronto, Ontario, Canada, M3J 0K2
        • Canadian Phase Onward
  • Mexico
      • Chihuahua City, Mexico, 31000
        • Investigacion y Biomedicina de Chihuahua
    • Jalisco
      • Guadalajara, Jalisco, Mexico, 44210
        • Consultorio Medico
    • Nuevo León
      • Monterrey, Nuevo León, Mexico, 64610
        • Clínica García Flores SC
      • Monterrey, Nuevo León, Mexico, 64020
        • IMED Internal Medicine Clin Trials
      • San Nicolás de los Garza, Nuevo León, Mexico, 66465
        • Unidad Médica para la Salud Integral
    • Tamaulipas
      • Ciudad Madero, Tamaulipas, Mexico, 89440
        • Centro de Estudios de Investigacion Metabolicos y Cardiovasculares
    • Yucatán
      • Mérida, Yucatán, Mexico, 97070
        • Kohler and Milstein Research S.A. de C.V.
  • Spain
      • A Coruña, Spain, 15006
        • CHUAC-Complejo Hospitalario Universitario A Coruña
      • Seville, Spain, 41003
        • Clínica nuevas Tecnologías en Diabetes y Endocrinología (NTDE)
    • A Coruña
      • Ferrol, A Coruña, Spain, 15405
        • Complejo Hospitalario Universitario de Ferrol (CHUF)- Hospital Naval")
    • Andalusia
      • Córdoba, Andalusia, Spain, 14004
        • Hospital Universitario Reina Sofia
      • Málaga, Andalusia, Spain, 29004
        • Hospital Quirón Málaga
    • Catalonia
      • Barcelona, Catalonia, Spain, 08041
        • Hospital de la Santa Creu i Sant Pau
    • Madrid
      • San Sebastián de los Reyes, Madrid, Spain, 28702
        • Hospital Universitario Infanta Sofía
    • Valenciana
      • Valencia, Valenciana, Spain, 46014
        • Hospital General Universitario de Valencia
  • United Kingdom
      • Sheffield, United Kingdom, S2 5FX
        • Panthera Biopartners - Sheffield
    • Leicestershire
      • Leicester, Leicestershire, United Kingdom, LE5 4PW
        • Leicester General Hospital
    • London
      • Enfield, London, United Kingdom, EN3 4GS
        • Panthera Biopartners - North London
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85053
        • Arizona Research Center
    • California
      • San Diego, California, United States, 92103
        • Artemis Institute for Clinical Research
    • Connecticut
      • Waterbury, Connecticut, United States, 06708
        • Chase Medical Research, LLC
    • Florida
      • Miami, Florida, United States, 33135
        • Suncoast Research Group
    • Georgia
      • Woodstock, Georgia, United States, 30189
        • North Georgia Clinical Research
    • Idaho
      • Blackfoot, Idaho, United States, 83221
        • Elite Clinical Trials
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern University
    • Massachusetts
      • Waltham, Massachusetts, United States, 02451
        • MedVadis Research Corporation
    • Michigan
      • Bay City, Michigan, United States, 48706
        • Great Lakes Research Group, Inc.
    • Missouri
      • Springfield, Missouri, United States, 65807
        • Clinvest Research LLC
    • Texas
      • Dallas, Texas, United States, 75211
        • Mercy Family Clinic
      • San Antonio, Texas, United States, 78229
        • Clinical Trials of Texas, Inc.
    • Washington
      • Bellevue, Washington, United States, 98007
        • Northwest Clinical Research Center

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:

  • Have a body mass index (BMI) ≥27 kilogram/kg/m² at screening.
  • Have a history of at least 1 self-reported unsuccessful dietary effort to lose body weight.
  • Have index knee pain for >12 weeks prior to screening, and presence of index knee pain for >15 days over the previous month.
  • Have knee X-ray with moderate radiographic changes (Kellgren-Lawrence Grade 2 or 3) per central reading at screening.
  • Currently meets American College of Rheumatology (ACR) Criteria (clinical and radiological) for OA.

Exclusion Criteria:

  • Have had steroid joint injections within 90 days of screening.
  • Have had other joint injections and procedures within 6 months of screening.
  • Have joint disease other than osteoarthritis.
  • Have a self-reported or documented change in body weight >5 kg (11 pounds) within 90 days prior to screening.
  • Have been taking weight loss drugs, including over-the-counter medications, within 90 days prior to screening.
  • Have a prior or planned surgical treatment for obesity.
  • Have diabetes mellitus.

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
Placebo Comparator: Placebo
Participants will receive placebo.
Drug: Placebo
Administered SC
Experimental: Retatrutide Dose 1
Participants will receive retatrutide subcutaneously (SC).
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Experimental: Retatrutide Dose 2
Participants will receive retatrutide SC.
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Subscale Score
Time Frame: Baseline, Week 68
Baseline, Week 68
Percent Change from Baseline in Body Weight
Time Frame: Baseline, Week 68
Baseline, Week 68

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in the WOMAC Physical Function Subscale Score
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Waist Circumference
Time Frame: Baseline, Week 68
Baseline, Week 68
Percent Change from Baseline in Total Cholesterol
Time Frame: Baseline, Week 68
Baseline, Week 68
Percent Change from Baseline in Triglycerides
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Body Mass Index (BMI)
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Systolic Blood Pressure (SBP)
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Diastolic Blood Pressure (DBP)
Time Frame: Baseline, Week 68
Baseline, Week 68
Percent Change from Baseline in Fasting Insulin
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Short Form 36-Version 2 (SF-36v2) Acute Form Physical Functioning Domain Score
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Average Pain Intensity Numeric Rating Score (API-NRS) Score
Time Frame: Baseline, Week 68
Baseline, Week 68
Change from Baseline in Worst Pain Intensity Numeric Rating Score (WPI-NRS) Score
Time Frame: Baseline, Week 68
Baseline, Week 68

Collaborators and Investigators

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

Sponsor

Eli Lilly and Company

Investigators

  • Study Director: Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST), Eli Lilly and Company

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)

August 1, 2023

Primary Completion (Actual)

November 14, 2025

Study Completion (Actual)

November 14, 2025

Study Registration Dates

First Submitted

June 27, 2023

First Submitted That Met QC Criteria

June 27, 2023

First Posted (Actual)

July 5, 2023

Study Record Updates

Last Update Posted (Actual)

January 21, 2026

Last Update Submitted That Met QC Criteria

January 20, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 18583
  • J1I-MC-GZBN (Other Identifier: Eli Lilly and Company)
  • 2023-503660-17-00 (Other Identifier: EU Trial Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

IPD Sharing Time Frame

Data are available 6 months after the primary publication and approval of the indication studied in the US and European Union (EU), whichever is later. Data will be indefinitely available for requesting.

IPD Sharing Access Criteria

A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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