- Design
- Phase 3, randomised, double-blind, placebo-controlled, 92 sites in 8 countries
- Population
- 1,152 adults with type 2 diabetes (HbA1c 6.5–10.5%) and BMI ≥27, on diet or up to three oral agents
- Primary outcome
- Percentage change in body weight at 80 weeks, 9 mg and 12 mg vs placebo
- Effect
- −16.8% (9 mg) and −18.8% (12 mg) vs −5.1%; difference at 12 mg −13.8% (95% CI −15.8 to −11.8)
TRIUMPH-2 randomised 1,152 adults with type 2 diabetes and a BMI of 27 or more to once-weekly retatrutide 4, 9 or 12 mg or placebo for 80 weeks. Retatrutide acts on GIP, GLP-1 and glucagon receptors. Participants had a mean BMI of 38, a mean HbA1c of 7.7% and had lived with diabetes for a median of about five and a half years; almost all were on oral glucose-lowering drugs and none on insulin.
Mean weight change was −11.9%, −16.8% and −18.8% across the three doses against −5.1% on placebo, so the placebo-adjusted losses were about 7%, 12% and 14%. The authors report better glycaemic control alongside, though the HbA1c figures are not in the abstract.
The cost was tolerability. Diarrhoea affected about a third and nausea up to 28% at the top dose. Hypotension (6% at 12 mg) and dysaesthesia (7%) were more frequent than on placebo, and 12% stopped the 9 mg dose for adverse events. Weight loss in people with diabetes is classically smaller than in those without, and these figures sit at the upper end of what incretin trials have shown in this group.
Nothing changes in clinic yet. Retatrutide has no approval from the FDA, EMA or CDSCO, and its Indian position is unknown. What the trial does is set the bar the current agents will be compared against when it does arrive.
- Retatrutide is investigational and not approved by the FDA, EMA or CDSCO; it cannot be prescribed outside a trial.
- When patients ask about it, the realistic placebo-adjusted weight loss in type 2 diabetes was about 12–14% at the higher doses over 80 weeks.
- Expect gastrointestinal effects in about a third of patients if it is approved, with stopping for adverse events most common at 9 mg.
- Hypotension rose with dose (6% at 12 mg), so review antihypertensives in anyone losing weight fast on any incretin drug.
- Dysaesthesia (abnormal skin sensation) was a signal in this trial; ask about it rather than attributing it to neuropathy.
Why it matters
It raises the benchmark for weight loss in type 2 diabetes, where weight has always been harder to shift than in obesity alone.
Don't overread it
Weight was the primary endpoint; there are no cardiovascular or kidney outcome data yet.
The statistics, in plain English
The 'treatment difference' is the extra weight lost beyond placebo: −13.8% at 12 mg, with a 95% confidence interval of −15.8% to −11.8%. The whole interval is far from zero, so the effect is not a chance finding. The figures use a 'treatment regimen' estimate, which counts people who stopped the drug, so they reflect what happens in a real group rather than only in those who tolerated it.
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