A Study of Retatrutide (LY3437943) in the Maintenance of Weight Reduction in Individuals With Obesity (TRIUMPH-6)

February 27, 2026 updated by: Eli Lilly and Company

A Phase 3b, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate Retatrutide Treatment in the Maintenance of Weight Reduction in Individuals With Obesity

This is a study of retatrutide in participants with obesity. The main purpose is to learn more about how retatrutide maintains body weight loss. The study will have two treatment phases: an 80 week lead-in phase in which all participants will take retatrutide dose 1 and a 36 week randomized, double-blinded phase in which participants will either take retatrutide dose 1, retatrutide dose 2, or switch to placebo. Participation in the study will last around 125 weeks.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

643

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

  • Canada
      • Brampton, Canada, L6T 0G1
        • Aggarwal and Associates Limited
      • Burlington, Canada, L7M 1K9
        • Circulate Cardiac & Vascular Centre
      • Courtice, Canada, L1E 2J5
        • Med Trust Research
      • Hamilton, Canada, L8J 0B6
        • Winterberry Research Inc.
      • Terrebonne, Canada, J6X 4P7
        • Centre de Medecine Metabolique de Lanaudiere (CMML)
      • Thunder Bay, Canada, P7B 7C7
        • Care Access - Thunder Bay - Barton Street
      • Toronto, Canada, M5G 1K2
        • Maple Leaf Research
      • Trois-Rivières, Canada, G8T 7A1
        • C.I.C. Mauricie inc.
  • United Kingdom
      • Birmingham, United Kingdom, B21 9RY
        • FutureMeds - Birmingham
      • Blackburn, United Kingdom, BB2 1AX
        • Oakenhurst Medical Practice
      • Blackpool, United Kingdom, FY3 7EN
        • Layton Medical Centre
      • Bradford-on-Avon, United Kingdom, BA15 1DQ
        • Bradford on Avon Health Centre
      • Bromborough, United Kingdom, CH62 6EE
        • FutureMeds - Liverpool
      • Cheadle, United Kingdom, ST10 1NS
        • Cheadle Community Hospital
      • Hounslow, United Kingdom, TW4 7NR
        • HMC Health Group - Meadows Centre for Health
      • Oxford, United Kingdom, OX4 1XB
        • St Bartholomew's Medical Centre
      • Penzance, United Kingdom, TR18 3DX
        • Atlantic Medical
      • Poole, United Kingdom, BH16 5PW
        • The Adam Practice
      • Rotherham, United Kingdom, S61 1AH
        • Woodstock Bower Surgery
      • Torpoint, United Kingdom, PL11 2TB
        • Rame Group Practice
  • United States
    • California
      • Santa Ana, California, United States, 92701
        • Southern California Clinical Research
    • Colorado
      • Aurora, Colorado, United States, 80045
        • University of Colorado Anschutz Medical Campus
    • Connecticut
      • Hamden, Connecticut, United States, 06517
        • CMR of Greater New Haven, LLC
    • Florida
      • Cooper City, Florida, United States, 33024
        • ALL Medical Research, LLC
      • Coral Gables, Florida, United States, 33134
        • Florida International Medical Research
      • Ocala, Florida, United States, 34470
        • Renstar Medical Research
      • Orlando, Florida, United States, 32803
        • Charter Research - Winter Park
      • West Palm Beach, Florida, United States, 33401
        • Metabolic Research Institute, Inc.
    • Georgia
      • Marietta, Georgia, United States, 30062
        • Kubost Clinical Research - Marietta
      • Woodstock, Georgia, United States, 30189
        • North Georgia Clinical Research
    • Hawaii
      • Honolulu, Hawaii, United States, 96817
        • Pacific Diabetes & Endocrine Center
    • Illinois
      • Oak Brook, Illinois, United States, 60523
        • Alliance for Multispecialty Research, LLC
      • Springfield, Illinois, United States, 62703
        • Springfield Clinic Main Campus
    • Kentucky
      • Lexington, Kentucky, United States, 40509
        • Alliance for Multispecialty Research, LLC
      • Louisville, Kentucky, United States, 40213
        • L-MARC Research Center
    • Louisiana
      • Baton Rouge, Louisiana, United States, 70808
        • Pennington Biomedical Research Center
      • Lake Charles, Louisiana, United States, 70601
        • Care Access - Lake Charles (Bayou Pines)
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
    • Missouri
      • Kansas City, Missouri, United States, 64114
        • Alliance for Multispecialty Research, LLC
    • Nevada
      • Las Vegas, Nevada, United States, 89128
        • Vector Clinical Trials
    • New York
      • Amherst, New York, United States, 14226
        • Dent Neurosciences Research Center, Inc
    • North Carolina
      • Morehead City, North Carolina, United States, 28557
        • Carteret Medical Group
      • Raleigh, North Carolina, United States, 27607
        • Care Access - Raleigh
    • Oklahoma
      • Moore, Oklahoma, United States, 73160
        • Tekton Research, LLC.
    • Pennsylvania
      • Duncansville, Pennsylvania, United States, 16635
        • Altoona Center For Clinical Research
    • South Dakota
      • Rapid City, South Dakota, United States, 57701
        • Care Access - Rapid City
    • Tennessee
      • Knoxville, Tennessee, United States, 37909
        • Alliance for Multispecialty Research, LLC
    • Texas
      • Houston, Texas, United States, 77054
        • Care Access - Houston
      • Mesquite, Texas, United States, 75149
        • Southern Endocrinology Associates
      • San Antonio, Texas, United States, 78229
        • Sleep Therapy Research Center
    • Virginia
      • Richmond, Virginia, United States, 23294
        • National Clinical Research, Inc
    • Washington
      • Bellevue, Washington, United States, 98007
        • Northwest Clinical Research Center
      • Wenatchee, Washington, United States, 98801
        • Central Washington Health Services Association d/b/a Confluence Health

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 obesity and a history of at least one self-reported unsuccessful dietary effort to reduce body weight

Exclusion Criteria:

  • Have a self-reported change in body weight >5 kilograms (kg) (11 pounds) within 90 days before screening
  • Have a prior or planned surgical treatment for obesity
  • Have a prior or planned endoscopic procedure and/or device-based therapy for obesity
  • Have Type 1 Diabetes, Type 2 Diabetes, or any other type of diabetes
  • Have a family or personal history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN-2)

  • Have had within the past 90 days before screening:

    • acute myocardial infarction
    • cerebrovascular accident (stroke)
    • hospitalization for unstable angina, or
    • hospitalization due to congestive heart failure
  • Have New York Heart Association Functional Classification Class IV congestive heart failure
  • Have a history of chronic or acute pancreatitis
  • Have taken weight loss drugs, including over-the-counter medications, within 90 days prior to screening

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: Retatrutide Dose 1
Participants will receive retatrutide dose 1 administered subcutaneously (SC) for 116 weeks
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Experimental: Retatrutide Dose 1 to Retatrutide Dose 2
Participants will receive retatrutide dose 1 administered SC for 80 weeks, then retatrutide dose 2 administered SC for an additional 36 weeks
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Placebo Comparator: Retatrutide Dose 1 to Placebo
Participants will receive retatrutide dose 1 administered SC for 80 weeks, then placebo administered SC for an additional 36 weeks
Drug: Placebo
Administered SC
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent Change from Baseline in Body Weight
Time Frame: Week 0, Week 116
Week 0, Week 116

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in Waist Circumference
Time Frame: Week 0, Week 116
Week 0, Week 116
Percentage of Body Weight Reduction Achieved at Week 80 that is Maintained at Week 116
Time Frame: Week 0, Week 80, Week 116
Week 0, Week 80, Week 116
Change from Baseline in Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT)
Time Frame: Week 0, Week 116
Week 0, Week 116

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 8 AM - 8 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)

March 5, 2025

Primary Completion (Estimated)

April 1, 2028

Study Completion (Estimated)

April 1, 2028

Study Registration Dates

First Submitted

February 28, 2025

First Submitted That Met QC Criteria

February 28, 2025

First Posted (Actual)

March 5, 2025

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 27, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 27268
  • J1I-MC-GZQB (Other Identifier: Eli Lilly and Company)

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 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.

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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