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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
445

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: There may be multiple sites in this clinical trial. 1-877-CTLILLY (1-877-285-4559) or
  • Phone Number: 1-317-615-4559
  • Email: ClinicalTrials.gov@lilly.com

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Eli Lilly and Company

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 14, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 14, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 27, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 27, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 5, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 21, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 20, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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