Retatrutide Phase 3 Trials: Research Summary
For laboratory research use only. Not for human use. Research use only.
Retatrutide is currently in Phase 3 clinical development across multiple indications. This research summary covers the available Phase 2 data, the ongoing Phase 3 programme (TRIUMPH), and what the results mean for metabolic disease research.
Phase 2 Results Summary
The Phase 2 RETATRUTIDE trial (NCT04881760) enrolled 338 participants with obesity (BMI ≥30) or overweight (BMI ≥27) with at least one weight-related comorbidity. Participants were randomised to receive weekly subcutaneous injections of Retatrutide at doses of 1mg, 4mg, 8mg, or 12mg, or placebo, for 48 weeks.
Results published in The New England Journal of Medicine (2023) demonstrated dose-dependent weight reduction. The 12mg dose group achieved a mean weight reduction of 24.2% from baseline — the largest pharmacological weight reduction observed in a clinical trial at that time. The 8mg dose group achieved 22.8% mean weight reduction.
TRIUMPH Phase 3 Programme
The TRIUMPH programme encompasses multiple Phase 3 trials examining Retatrutide across different indications. TRIUMPH-1 examines obesity without diabetes; TRIUMPH-2 examines type 2 diabetes; TRIUMPH-3 examines non-alcoholic steatohepatitis (NASH); and TRIUMPH-4 examines cardiovascular outcomes.
Phase 3 trials are powered to demonstrate superiority over existing treatments and to characterise the long-term safety profile. Results from the primary TRIUMPH trials are expected in 2026-2027.
Comparison with Other GLP-1 Class Agents
Phase 2 data suggests Retatrutide produces greater weight reduction than both Semaglutide (approximately 15% in STEP trials) and Tirzepatide (approximately 22% in SURMOUNT-1). The additional glucagon receptor agonism in Retatrutide is hypothesised to contribute to greater energy expenditure compared to GLP-1 or dual GIP/GLP-1 agonists.
Head-to-head comparative trials are not yet available. The Phase 3 programme will provide more definitive data on Retatrutide's efficacy relative to existing approved agents.
Frequently Asked Questions
When will Retatrutide Phase 3 results be available?
Phase 3 TRIUMPH trial results are expected in 2026-2027. Eli Lilly has indicated regulatory submissions are planned following Phase 3 completion.
Is Retatrutide approved in Australia?
Retatrutide is not currently TGA-approved in Australia. It is available for laboratory research use only through PeptideIQ.
Disclaimer: All products supplied by PeptideIQ are for laboratory research use only. They are not approved for human use, consumption, or therapeutic application. PeptideIQ complies with all applicable Australian regulations including the Therapeutic Goods Act 1989.