The TRIUMPH program
Lilly officially announced the TRIUMPH pivotal program comprising 5 phase 3 trials: TRIUMPH-1 (obesity, ~2,000 participants), TRIUMPH-2 (obesity with cardiovascular risk, ~2,700), TRIUMPH-3 (T2 diabetes + obesity, ~1,800), TRIUMPH-4 (maintenance), TRIUMPH-MASH (steatohepatitis). Together they add up to more than 14,000 participants — the largest obesity program ever filed.
Why expectations are so high
In phase 2 published in The New England Journal of Medicine (June 2023), retatrutide reached a mean loss of 24.2% at 48 weeks at the max dose of 12 mg weekly — higher than any prior tirzepatide or semaglutide result over comparable windows. Retatrutide is a triple agonist: GLP-1 + GIP + glucagon, the first drug filed that targets all three axes simultaneously.
Timeline and market
First TRIUMPH-1 readouts expected H2 2026. FDA filing anticipated end of 2026, approval mid-2027 if everything stays on schedule. Bank of America analysts project peak sales of $35 billion annually — more than Mounjaro and Wegovy combined today.
Open risks
The added glucagon mechanism is precisely the component driving the most nausea and heart-rate elevation in prior studies. The question is whether retatrutide can keep its efficacy edge without blowing up adverse-event-driven discontinuation rates. Phase 2 showed 16% discontinuation at the high dose — comparable to tirzepatide but above semaglutide.
Source: ClinicalTrials.gov · TRIUMPH-1