Clinical Trials
Frequently asked questions about retatrutide's clinical trial program, including Phase 2 results and the ongoing Phase 3 TRIUMPH studies.
What clinical trials have been completed for retatrutide?
As of early 2025, retatrutide has completed Phase 1 (first-in-human safety and PK study) and Phase 2 clinical trials. The Phase 2 program included a 48-week obesity trial (NCT04881706, published in the New England Journal of Medicine) and a 36-week type 2 diabetes trial (NCT04867785, published in The Lancet). Both produced positive results that supported advancement to Phase 3.
What were the main results of the Phase 2 obesity trial?
The Phase 2 obesity trial demonstrated mean weight loss of up to 24.2% at 48 weeks in the highest dose group (12 mg), with 100% of participants at that dose losing at least 5% of body weight. The trial also showed an approximately 82% relative reduction in liver fat, improvements in blood pressure and lipids, and a manageable gastrointestinal side effect profile. These were the highest weight loss results ever reported for a pharmacological agent.
What were the main results of the Phase 2 diabetes trial?
The Phase 2 type 2 diabetes trial showed HbA1c reductions of up to 2.02 percentage points at 36 weeks in the highest dose group. Approximately 95% of participants at the highest dose achieved an HbA1c below 7.0% (the standard treatment target), and approximately 62% reached HbA1c below 5.7% (the non-diabetic range). Retatrutide at higher doses significantly outperformed the active comparator, dulaglutide 1.5 mg.
What is the TRIUMPH program?
TRIUMPH (Triple Receptor Agonist Intervention Utilizing Metabolic Pathways in Health) is the Phase 3 clinical development program for retatrutide. It includes TRIUMPH-1 (the pivotal obesity trial) and TRIUMPH-2 (the pivotal type 2 diabetes trial), along with potentially other studies. These large-scale trials will provide the definitive data needed for regulatory approval decisions.
When will Phase 3 results be available?
Specific timelines depend on enrollment progress and other factors, but Phase 3 primary results are generally expected in the 2025-2027 timeframe. Phase 3 obesity trials typically require 68-72 weeks of treatment, followed by data analysis and reporting. Eli Lilly has not publicly committed to specific readout dates.
Can I participate in a retatrutide clinical trial?
This resource does not facilitate clinical trial enrollment. If you are interested in participating in a clinical trial, discuss this with your healthcare provider or search for registered studies on ClinicalTrials.gov using the search term 'retatrutide' or 'LY3437943'. Eligibility criteria vary by trial and are determined by the study investigators.