TRIUMPH-1: Retatrutide in Adults with Obesity or Overweight
NCT05929066 · Eli Lilly
- Phase
- Phase 3
- Enrollment
- Lilly reported 2,339 randomized; ClinicalTrials.gov actual enrollment: 2,335
- Est. completion
- Topline results reported May 21, 2026
- Sponsor
- Eli Lilly
Background
TRIUMPH-1 is a Phase 3 clinical trial evaluating once-weekly retatrutide in adults with obesity or overweight without diabetes. Participants were randomized to retatrutide 4 mg, 9 mg, 12 mg, or placebo. Lilly reported that 2,339 participants were randomized in TRIUMPH-1. ClinicalTrials.gov lists actual enrollment of 2,335 participants. The small difference reflects reporting between the sponsor's randomized population and the ClinicalTrials.gov study record. The primary weight-management endpoint was evaluated at 80 weeks. Sources: Eli Lilly and Company; ClinicalTrials.gov NCT05929066.
Key result
In Lilly's topline Phase 3 results, mean body-weight reductions at 80 weeks were: 19.0% with retatrutide 4 mg; 25.9% with retatrutide 9 mg; 28.3% with retatrutide 12 mg. These results are Phase 3 topline findings reported by Eli Lilly and should not be confused with the earlier 48-week Phase 2 obesity trial. Retatrutide remains investigational and is not FDA approved. Lilly has stated that it plans to submit retatrutide for regulatory review in Q1 2027. Sources: Eli Lilly and Company; ClinicalTrials.gov NCT05929066.
Primary endpoint
Percent change in body weight from baseline at 80 weeks
Secondary endpoints
- Proportion achieving ≥ 5% body weight reduction
- Proportion achieving ≥ 10% body weight reduction
- Proportion achieving ≥ 15% body weight reduction
- Proportion achieving ≥ 20% body weight reduction
- Change in waist circumference
- Change in systolic blood pressure
- Change in fasting lipids
- Pain and function outcomes in osteoarthritis subset
- AHI reduction in obstructive sleep apnea subset
Population
Adults with obesity (BMI ≥ 30) or overweight (BMI ≥ 27) with ≥ 1 weight-related comorbidity, without type 2 diabetes; includes subsets with osteoarthritis and obstructive sleep apnea
Intervention
Retatrutide randomized to 4 mg, 9 mg, or 12 mg SC once weekly vs. placebo; participants started at 2 mg with stepwise escalation at 4-week intervals per trial protocol
Inclusion criteria
Adults ≥ 18 years; BMI ≥ 30 kg/m², or BMI ≥ 27 kg/m² with ≥ 1 weight-related comorbidity; no type 2 diabetes diagnosis
Exclusion criteria
Type 2 diabetes; prior bariatric surgery; use of weight-loss medications in prior 3 months; personal or family history of medullary thyroid carcinoma or MEN2; recent cardiovascular event (< 6 months)
Trial information sourced from ClinicalTrials.gov and published literature. TryTrutide is not affiliated with Eli Lilly or any trial site. This is not medical advice.