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Lilly’s triple agonist contender for best-in-class weight loss

Retatrutide’s 26.6% weight loss is the most yet at 68 weeks, perhaps too much for some patients

December 12, 2025 1:49 AM UTC

Top-line Phase III data from Lilly’s retatrutide — a triple agonist of GLP-1, GIP and GCGR — suggest best-in-class weight loss that could help maintain the pharma’s leadership position in obesity.

On Thursday, Eli Lilly and Co. (NYSE:LLY) announced results from the 445-patient Phase III TRIUMPH-4 study evaluating 9 mg and 12 mg subcutaneous, once-weekly doses of retatrutide in adults with obesity and knee osteoarthritis. The highest dose of 12 mg led to placebo-adjusted weight loss of 26.6% after 68 weeks of treatment, corresponding to a 30.2 kg (67.5 lb) placebo-adjusted drop in weight...