Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial
Bellido et al. (2026). The Lancet.
Summary
A phase 3 trial of retatrutide in 1,152 adults with obesity and type 2 diabetes, randomised to one of three retatrutide dose levels or placebo for 80 weeks. Mean body weight fell by 11.9%, 16.8% and 18.8% across the three retatrutide groups against 5.1% with placebo. Gastrointestinal events were more common with retatrutide: diarrhoea in 27 to 34% against 13% on placebo, and nausea in 14 to 28% against 8%. Seven participants died during the trial and the deaths were judged unrelated to the intervention. The trial was funded by Eli Lilly, which develops retatrutide, and several authors disclose consultancy or advisory roles with drug companies. Retatrutide is investigational and not an approved medicine.