Phase 3 retatrutide trials report weight loss and reduced knee pain

Two Northwestern University-led Phase 3 trials involving more than 1,000 adults found that participants receiving high doses of Eli Lilly's experimental retatrutide lost, on average, up to 25% of their body weight. Across the studies, around two-thirds receiving the drug reported at least a 50% reduction in knee osteoarthritis pain; placebo recipients reported a 38% reduction in pain. The once-weekly injection activates three hormone receptors. Researchers said reduced weight lessens the load on knees, but the contribution of anti-inflammatory effects needs further study. Whether people who are not overweight could benefit also remains unresolved. Both trials were published in the New England Journal of Medicine, and study co-authors include Lilly scientists.