Lilly's three-hormone obesity pill posts up to 22.6% weight loss in late trials

Retatrutide met its primary endpoints in two phase 3 trials, but the data showed no clear cardiovascular benefit.

Eli Lilly reported that retatrutide, a drug hitting the GIP, GLP-1 and glucagon receptors, met the primary endpoints of two phase 3 obesity trials. In TRIUMPH-3, which enrolled 1,949 patients with severe obesity and existing cardiovascular disease, the 12 mg dose produced 22.6% weight loss at 80 weeks versus 3.2% on placebo. In TRIUMPH-2, covering 1,152 patients with type 2 diabetes, the same dose delivered 20.8%. Earlier trials showed even higher figures, around 28%, in other patient groups.

The metabolic markers moved sharply: the 12 mg dose cut triglycerides by 37%, non-HDL cholesterol by 16.5%, and a key inflammation marker by 51.2%. But cardiovascular outcomes were murkier. TRIUMPH-3 recorded 44 major adverse cardiac events in the drug arms versus 52 on placebo, with events rarer than expected in both groups, so no clear cardiac benefit could be claimed.

For abundance, the significance is a potent obesity therapy in oral form, which could ease manufacturing and distribution constraints that limit injectable drugs. Lilly plans to file with the FDA in the first quarter of 2027, with a peak sales estimate of $6.6 billion.

Tolerability tempers the picture. Diarrhea affected up to a third of high-dose patients and nausea up to 38%, and discontinuations ran from 7.7% to 13.5%. Analysts note the weight-loss numbers use an estimand counting only patients staying on regimen, and some see retatrutide as a more niche option likely reserved for higher-BMI patients.

Source: Fierce Biotech