ObesityPhase 3TRIUMPH-5NCT06662383
A Study of Retatrutide (LY3437943) Compared to Tirzepatide (LY3298176) in Adults Who Have Obesity
A Phase 3 study testing Retatrutide and Tirzepatide in people with Obesity, run by Eli Lilly and Company at 65 sites in 5 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obesity
- What is being tested?
- Retatrutide and Tirzepatide
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 800 participants
- Where
- 65 sitesin 5 countries
- Study dates
- 1 Nov 2024to Dec 2026
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Have obesity and a history of at least one self-reported unsuccessful dietary effort to reduce body weight.
Who cannot join
- 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:
Show all 13Show fewer
- 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.
Trial locations and contacts
65 sites in 5 countries.
65 sites in 5 countries
United States40 sites
Albany Medical College, Division of Community Endocrinology
Albany, New York, 12203
Lynn Institute of Denver
Aurora, Colorado, 80012
Pennington Biomedical Research Center
Baton Rouge, Louisiana, 70808
Great Lakes Research Group, Inc.
Bay City, Michigan, 48706
Bridgeport Hospital
Bridgeport, Connecticut, 06610
Headlands Horizons LLC
Brownsville, Texas, 78526
Charlottesville Medical Research
Charlottesville, Virginia, 22911
WR-Clinsearch, LLC
Chattanooga, Tennessee, 37421
Northwestern University
Chicago, Illinois, 60611
StudyMetrix Research
City of Saint Peters, Missouri, 63303
ClinCept Clinical Research - MH
Columbus, Georgia, 31904
PriMED Clinical Research
Dayton, Ohio, 45429
Lillestol Research
Fargo, North Dakota, 58104
Northeast Georgia Medical Center
Gainesville, Georgia, 30501
PharmQuest Life Sciences, LLC
Greensboro, North Carolina, 27408
Tribe Clinical Research, LLC
Greenville, South Carolina, 29607
Las Vegas Endocrinology
Henderson, Nevada, 89074
Encore Medical Research
Hollywood, Florida, 33024
East-West Medical Research Institute
Honolulu, Hawaii, 96814
Next Level Urgent Care
Houston, Texas, 77057
Houston Research Institute
Houston, Texas, 77079
Suncoast Research Group
Miami, Florida, 33135
Onhealth Research Center
Miami, Florida, 33186
Monroe Biomedical Research
Monroe, North Carolina, 28112
Yale University School of Medicine
New Haven, Connecticut, 06519
New York Gastroenterology Associates
New York, New York, 10075
Mary & Dick Allen Diabetes Center
Newport Beach, California, 92663
Artemis Institute for Clinical Research
San Diego, California, 92103
Consano Clinical Research, LLC
Shavano Park, Texas, 78231
Great Lakes Research Institute
Southfield, Michigan, 48075
Encompass Clinical Research
Spring Valley, California, 91978
Chrysalis Clinical Research
St. George, Utah, 84790
Pivotal Research Solutions
Stonecrest, Georgia, 30038
Precision Clinical Research
Sunrise, Florida, 33351
Medical Advancement Centers of Arizona
Tempe, Arizona, 85283
Westchester Medical Center
Valhalla, New York, 10595
Einstein Clinical Research
Vero Beach, Florida, 32960
Diablo Clinical Research, Inc.
Walnut Creek, California, 94598
Integrated Clinical Trial Services, Inc.
West Des Moines, Iowa, 50265
Accellacare - Wilmington
Wilmington, North Carolina, 28401
Poland10 sites
Uniwersytecki Szpital Kliniczny w Białymstoku
Bialystok, Podlaskie Voivodeship, 15-276
Gabinet Leczenia Otylosci i Chorob Dietozaleznych - dr hab. n. med. Lucyna Ostrowska
Bialystok, Podlaskie Voivodeship, 15-281
Zdrowie Osteo-Medic
Bialystok, Podlaskie Voivodeship, 15-351
NZOZ Specjalistyczny Ośrodek Internistyczno-Diabetologiczny
Bialystok, Podlaskie Voivodeship, 15-435
Centrum Terapii Wspolczesnej J. M. Jasnorzewska Spolka Komandytowo-Akcyjna
Lodz, Łódź Voivodeship, 90-338
Gabinety TERPA
Lublin, Lublin Voivodeship, 20-333
Ekamed
Lublin, Lublin Voivodeship, 20-718
Centrum Zdrowia Metabolicznego Pawel Bogdanski
Poznan, Greater Poland Voivodeship, 60-589
Nzoz Neuro-Kard Ilkowski i Partnerzy SPL
Poznan, Greater Poland Voivodeship, 61-853
NZOZ Przychodnia Specjalistyczna Andrzej Wittek, Henryk Rudzki
Ruda Śląska, Silesian Voivodeship, 41-709
Germany9 sites
Zentrum fur klinische Forschung - Köln
Cologne, North Rhine-Westphalia, 51069
InnoDiab Forschung Gmbh
Essen, North Rhine-Westphalia, 45136
Medizentrum Essen Borbeck
Essen, North Rhine-Westphalia, 45355
Diabetes Zentrum Wilhelmsburg
Hamburg, 21109
Diabeteszentrum Hamburg West
Hamburg, 22607
AmBeNet GmbH
Leipzig, Saxony, 04107
Diabetologische Schwerpunktpraxis Dr. Staudenmeyer & Dr. Schiwietz
Lingen, Lower Saxony, 49808
RED-Institut GmbH
Oldenburg in Holstein, Schleswig-Holstein, 23758
Gemeinschaftspraxis Prof. Dr. med. Stephan Jacob, Dr. med. Frohmut Jacob
Villingen-Schwenningen, Baden-Wurttemberg, 78048
Argentina5 sites
Centro Médico Viamonte
Buenos Aires, Buenos Aires F.D., C1120AAC
Consultorio de Investigación Clínica EMO SRL
Buenos Aires, Buenos Aires F.D., C1405BUB
Centro Medico Dra. Laura Maffei- Investigacion Clinica Aplicada
Buenos Aires, Buenos Aires F.D., C1425AGC
Centro de Investigaciones Metabólicas (CINME)
Buenos Aires, C1056ABI
DIM Clínica Privada
Ramos Mejía, Buenos Aires, B1704ETD
About this study
Official title: 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.
- Conditions
- Obesity
- Being tested
- Retatrutide, Tirzepatide
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RetatrutideDrug
Also called LY3437943
Administered SC
TirzepatideDrug
Also called LY3298176
Administered SC
| Study group | Role | What they receive |
|---|---|---|
| Retatrutide | Experimental | Participants will receive retatrutide administered subcutaneously (SC) Receives: Drug: Retatrutide |
| Tirzepatide | Active comparator | Participants will receive tirzepatide administered SC Receives: Drug: Tirzepatide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent Change from Baseline in Body Weight
Measured: Baseline, Week 80
Secondary outcomes (9)
Change from Baseline in Body Mass Index (BMI)
Measured: Baseline, Week 80
Change from Baseline in Waist Circumference
Measured: Baseline, Week 80
Percent Change from Baseline in Total Cholesterol
Measured: Baseline, Week 80
Percent Change from Baseline in Triglycerides
Measured: Baseline, Week 80
Change from Baseline in Systolic Blood Pressure (SBP)
Measured: Baseline, Week 80
Change from Baseline in Diastolic Blood Pressure (DBP)
Measured: Baseline, Week 80
Change from Baseline in Hemoglobin A1c (HbA1c)
Measured: Baseline, Week 80
Percent Change from Baseline in Fasting Insulin
Measured: Baseline, Week 80
Change from Baseline in Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT)
Measured: Baseline, Week 80
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Oct 2024
- Study start1 Nov 2024
- Primary completionNov 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by Eli Lilly and CompanyThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 800 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Eli Lilly and Company
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- 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), Study director, Eli Lilly and Company
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06662383
- Sponsor's protocol ID
- 18585
- Other IDs
- J1I-MC-GZBP, 2024-511450-49-00
- Acronym
- TRIUMPH-5
- Status last verified
- Jul 2026
- First submitted
- 25 Oct 2024
- Last updated
- 20 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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.
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Randomized, Double-Blind Study to Evaluate the Efficacy and Safety of Retatrutide Compared to Tirzepatide in Adults Who Have Obesity
- ClinicalTrials.gov ID
- NCT06662383
- Acronym / sponsor ID
- TRIUMPH-5 / 18585
- Conditions
- Obesity
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 800 participants (estimated)
- Lead sponsor
- Eli Lilly and CompanyIndustry (pharma, biotech, devices)
- Study start
- 1 Nov 2024 (actual)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 28 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Retatrutide | Experimental | Drug: RetatrutideParticipants will receive retatrutide administered subcutaneously (SC) |
| Tirzepatide | Active comparator | Drug: TirzepatideParticipants will receive tirzepatide administered SC |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Have obesity and a history of at least one self-reported unsuccessful dietary effort to reduce body weight.
Key exclusion criteria (13 listed)
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RetatrutideAlso: LY3437943Administered SC | Drug | Retatrutide |
| TirzepatideAlso: LY3298176Administered SC | Drug | Tirzepatide |
Primary outcome
Percent Change from Baseline in Body Weight
Time frame: Baseline, Week 80
9 secondary outcomes
Change from Baseline in Body Mass Index (BMI)
Time frame: Baseline, Week 80
Change from Baseline in Waist Circumference
Time frame: Baseline, Week 80
Percent Change from Baseline in Total Cholesterol
Time frame: Baseline, Week 80
Percent Change from Baseline in Triglycerides
Time frame: Baseline, Week 80
Change from Baseline in Systolic Blood Pressure (SBP)
Time frame: Baseline, Week 80
Change from Baseline in Diastolic Blood Pressure (DBP)
Time frame: Baseline, Week 80
Change from Baseline in Hemoglobin A1c (HbA1c)
Time frame: Baseline, Week 80
Percent Change from Baseline in Fasting Insulin
Time frame: 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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2026.
- A Study of Retatrutide (LY3437943) Compared to Tirzepatide (LY3298176) in Adults Who Have Obesity (TRIUMPH-5)Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
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) study director
Eli Lilly and Company
65 sites in 5 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Retatrutide and Tirzepatide in people with Obesity, run by Eli Lilly and Company at 65 sites in 5 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 20 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 65 sites in United States, Poland, Germany, Argentina, Puerto Rico. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percent Change from Baseline in Body Weight (time frame: Baseline, Week 80). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2026.