A Study of Retatrutide (LY3437943) Compared to Tirzepatide (LY3298176) in Adults Who Have Obesity (TRIUMPH-5)

April 7, 2026 updated by: Eli Lilly and Company

A Phase 3, Randomized, Double-Blind Study to Evaluate the Efficacy and Safety of Retatrutide Compared to Tirzepatide in Adults Who Have Obesity

The main purpose of this study is to evaluate the efficacy and safety of retatrutide compared to tirzepatide in adults who have obesity. The study will last about 89 weeks.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

800

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

  • Argentina
      • Buenos Aires, Argentina, C1056ABI
        • Centro de Investigaciones Metabólicas (CINME)
    • Buenos Aires
      • Ramos Mejía, Buenos Aires, Argentina, B1704ETD
        • DIM Clinica Privada
    • Buenos Aires F.D.
      • Buenos Aires, Buenos Aires F.D., Argentina, C1120AAC
        • Centro Médico Viamonte
      • Buenos Aires, Buenos Aires F.D., Argentina, C1425AGC
        • Centro Medico Dra. Laura Maffei- Investigacion Clinica Aplicada
      • Buenos Aires, Buenos Aires F.D., Argentina, C1405BUB
        • Consultorio de Investigacion Clinica EMO SRL
  • Germany
      • Hamburg, Germany, 22607
        • Diabeteszentrum Hamburg West
      • Hamburg, Germany, 21109
        • Diabetes Zentrum Wilhelmsburg
    • Baden-Wurttemberg
      • Villingen-Schwenningen, Baden-Wurttemberg, Germany, 78048
        • Gemeinschaftspraxis Prof. Dr. med. Stephan Jacob, Dr. med. Frohmut Jacob
    • Lower Saxony
      • Lingen, Lower Saxony, Germany, 49808
        • Diabetologische Schwerpunktpraxis Dr. Staudenmeyer & Dr. Schiwietz
    • North Rhine-Westphalia
      • Cologne, North Rhine-Westphalia, Germany, 51069
        • Zentrum fur klinische Forschung - Köln
      • Essen, North Rhine-Westphalia, Germany, 45355
        • Medizentrum Essen Borbeck
      • Essen, North Rhine-Westphalia, Germany, 45136
        • InnoDiab Forschung GmbH
    • Saxony
      • Leipzig, Saxony, Germany, 04107
        • AmBeNet GmbH
    • Schleswig-Holstein
      • Oldenburg in Holstein, Schleswig-Holstein, Germany, 23758
        • RED-Institut GmbH
  • Poland
    • Greater Poland Voivodeship
      • Poznan, Greater Poland Voivodeship, Poland, 61-853
        • Nzoz Neuro-Kard Ilkowski i Partnerzy SPL
      • Poznan, Greater Poland Voivodeship, Poland, 60-589
        • Centrum Zdrowia Metabolicznego Pawel Bogdanski
    • Lublin Voivodeship
      • Lublin, Lublin Voivodeship, Poland, 20-718
        • Ekamed
      • Lublin, Lublin Voivodeship, Poland, 20-333
        • Gabinety TERPA
    • Podlaskie Voivodeship
      • Bialystok, Podlaskie Voivodeship, Poland, 15-351
        • Zdrowie Osteo-Medic
      • Bialystok, Podlaskie Voivodeship, Poland, 15-276
        • Uniwersytecki Szpital Kliniczny W Białymstoku
      • Bialystok, Podlaskie Voivodeship, Poland, 15-281
        • Gabinet Leczenia Otylosci i Chorob Dietozaleznych - dr hab. n. med. Lucyna Ostrowska
      • Bialystok, Podlaskie Voivodeship, Poland, 15-435
        • NZOZ Specjalistyczny Ośrodek Internistyczno-Diabetologiczny
    • Silesian Voivodeship
      • Ruda Śląska, Silesian Voivodeship, Poland, 41-709
        • NZOZ Przychodnia Specjalistyczna Andrzej Wittek, Henryk Rudzki
    • Łódź Voivodeship
      • Lodz, Łódź Voivodeship, Poland, 90-338
        • Centrum Terapii Wspolczesnej J. M. Jasnorzewska Spolka Komandytowo-Akcyjna
  • Puerto Rico
      • Ponce, Puerto Rico, 00716
        • Ponce Medical School Foundation Inc.
  • United States
    • Arizona
      • Tempe, Arizona, United States, 85283
        • Medical Advancement Centers of Arizona
    • California
      • Newport Beach, California, United States, 92663
        • Mary & Dick Allen Diabetes Center
      • San Diego, California, United States, 92103
        • Artemis Institute for Clinical Research
      • Spring Valley, California, United States, 91978
        • Encompass Clinical Research
      • Walnut Creek, California, United States, 94598
        • Diablo Clinical Research, Inc.
    • Colorado
      • Aurora, Colorado, United States, 80012
        • Lynn Institute of Denver
    • Connecticut
      • Bridgeport, Connecticut, United States, 06610
        • Bridgeport Hospital
      • New Haven, Connecticut, United States, 06519
        • Yale University School of Medicine
    • Florida
      • Hollywood, Florida, United States, 33024
        • Encore Medical Research
      • Miami, Florida, United States, 33135
        • Suncoast Research Group
      • Miami, Florida, United States, 33186
        • Onhealth Research Center
      • Sunrise, Florida, United States, 33351
        • Precision Clinical Research
      • Vero Beach, Florida, United States, 32960
        • Einstein Clinical Research
    • Georgia
      • Columbus, Georgia, United States, 31904
        • ClinCept Clinical Research - MH
      • Gainesville, Georgia, United States, 30501
        • Northeast Georgia Medical Center
      • Stonecrest, Georgia, United States, 30038
        • Pivotal Research Solutions
    • Hawaii
      • Honolulu, Hawaii, United States, 96814
        • East-West Medical Research Institute
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern University
    • Iowa
      • West Des Moines, Iowa, United States, 50265
        • Integrated Clinical Trial Services, Inc.
    • Louisiana
      • Baton Rouge, Louisiana, United States, 70808
        • Pennington Biomedical Research Center
    • Michigan
      • Bay City, Michigan, United States, 48706
        • Great Lakes Research Group, Inc.
      • Southfield, Michigan, United States, 48075
        • Great Lakes Research Institute
    • Missouri
      • City of Saint Peters, Missouri, United States, 63303
        • StudyMetrix Research
    • Nevada
      • Henderson, Nevada, United States, 89074
        • Las Vegas Endocrinology
    • New York
      • Albany, New York, United States, 12203
        • Albany Medical College, Division of Community Endocrinology
      • New York, New York, United States, 10075
        • New York Gastroenterology Associates
      • Valhalla, New York, United States, 10595
        • Westchester Medical Center
    • North Carolina
      • Greensboro, North Carolina, United States, 27408
        • PharmQuest Life Sciences, LLC
      • Monroe, North Carolina, United States, 28112
        • Monroe Biomedical Research
      • Wilmington, North Carolina, United States, 28401
        • Accellacare - Wilmington
    • North Dakota
      • Fargo, North Dakota, United States, 58104
        • Lillestol Research
    • Ohio
      • Dayton, Ohio, United States, 45429
        • PriMED Clinical Research
    • South Carolina
      • Greenville, South Carolina, United States, 29607
        • Tribe Clinical Research, LLC
    • Tennessee
      • Chattanooga, Tennessee, United States, 37421
        • WR-Clinsearch, LLC
    • Texas
      • Brownsville, Texas, United States, 78526
        • Headlands Horizons LLC
      • Houston, Texas, United States, 77057
        • Next Level Urgent Care
      • Houston, Texas, United States, 77079
        • Houston Research Institute
      • Shavano Park, Texas, United States, 78231
        • Consano Clinical Research, LLC
    • Utah
      • St. George, Utah, United States, 84790
        • Chrysalis Clinical Research
    • Virginia
      • Charlottesville, Virginia, United States, 22911
        • Charlottesville Medical Research

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 taken weight loss drugs, including over-the-counter medications, within 90 days prior to screening.
  • 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)
    • coronary revascularization
    • 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.

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
Participants will receive retatrutide administered subcutaneously (SC)
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Active Comparator: Tirzepatide
Participants will receive tirzepatide administered SC
Drug: Tirzepatide
Administered SC
Other Names:
  • LY3298176

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent Change from Baseline in Body Weight
Time Frame: Baseline, Week 80
Baseline, Week 80

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in Body Mass Index (BMI)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Waist Circumference
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Total Cholesterol
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Triglycerides
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Systolic Blood Pressure (SBP)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Diastolic Blood Pressure (DBP)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Hemoglobin A1c (HbA1c)
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Fasting Insulin
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT)
Time Frame: Baseline, Week 80
Baseline, Week 80

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)

November 1, 2024

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

October 25, 2024

First Submitted That Met QC Criteria

October 25, 2024

First Posted (Actual)

October 28, 2024

Study Record Updates

Last Update Posted (Actual)

April 13, 2026

Last Update Submitted That Met QC Criteria

April 7, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 18585
  • J1I-MC-GZBP (Other Identifier: Eli Lilly and Company)
  • 2024-511450-49-00 (Ctis)

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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