Eli Lilly announced highly positive topline results from the Phase 3 TRIUMPH-4 trial for retatrutide, its next-generation obesity drug. The triple agonist demonstrated up to 28.7% average weight loss over 68 weeks. This result involved patients with obesity and knee osteoarthritis, and significantly exceeded analyst expectations.
The trial also met key secondary endpoints. Retatrutide showed substantial improvements in pain and physical function for osteoarthritis patients. The safety profile remained generally consistent with existing incretin-based therapies, though some patient discontinuations were noted.
Eli Lilly shares rose approximately 3% in pre-market and morning trading on December 11, 2025, following the news. Analysts lauded the results as potentially "best-in-class," reinforcing the company’s dominant pipeline in the lucrative cardiometabolic health market. Seven additional Phase 3 trials for retatrutide are scheduled to conclude in 2026.