The investigational triple incretin agonist drug retatrutide was associated with significant improvement in knee osteoarthritis (OA) pain and physical function along with weight loss in people with painful knee osteoarthritis and obesity, data from two phase 3 trials showed.

“We saw very exciting amounts of pain reduction and function improvement over time. I think this is a big advance… Osteoarthritis has lacked effective therapies for so long,” study investigator Philip Conaghan, MBBS, PhD, director of the NIHR Biomedical Research Centre in Leeds and professor of musculoskeletal medicine at the University of Leeds, United Kingdom, told Medscape Medical News.

The data came from Eli Lilly’s TRIUMPH-4 trial, of once-weekly retatrutide in different doses compared with placebo for 68 weeks, and TRIUMPH-1-OA, a substudy of a larger trial investigating the triple GLP-1, GIP, and glucagon receptor agonist for treating obesity. Conaghan presented results from TRIUMPH-4 on November 8, 2026, and will present the TRIUMPH-1-OA data on November 10, 2026, both at the American College of Rheumatology (ACR) 2026 Annual Meeting in Orlando, Florida.