retatrutide knee osteoarthritis pain and weight loss trials, Digi Mart USA News: Two Phase 3 clinical trials involving more than 1,000 adults have strengthened the case for Eli Lilly’s experimental GLP-1-based drug retatrutide to be approved by the US Food and Drug Administration for both weight loss and relief from knee osteoarthritis (OA), according to a publisher report.
In two Northwestern University-led Phase 3 trials, people prescribed high doses of retatrutide lost, on average, up to 25% of their body weight. Across both studies, around two-thirds of those receiving the active injectable also reported at least a 50% reduction in knee OA pain.
Participants receiving the placebo self-reported a 38% reduction in OA pain.
Retatrutide is a next-generation triple-hormone receptor agonist drug. According to the report, it has so far been approved by the FDA only for what equates to “compassionate use,” which was reportedly granted to just one American.
The report says the trial results make a strong case for the drug to become the next weight-loss GLP-1 on the US market. Like earlier obesity medications, the drug also had secondary effects that included reduced blood pressure and inflammation.
Corresponding author Dr. Thomas Schnitzer of Northwestern University’s Feinberg School of Medicine said the findings suggest that people who are overweight and have OA may get a meaningful reduction in knee pain if they lose a significant amount of weight.
He said a major factor is that less weight loads the knees, reducing pain and allowing greater function. Schnitzer said some participants lost considerable amounts of weight, with a few losing up to 100 pounds or more.
The report notes that, unlike single- or dual-receptor drugs such as semaglutide or tirzepatide, a once-weekly retatrutide injection activates three natural hormone receptors, which resulted in a higher percentage of weight loss. The scientists acknowledge open questions, including whether people who are not overweight can benefit from the pain relief, and the mechanism behind the anti-inflammatory activity is not fully known.
Schnitzer described the work as a first step.
The report also notes that study co-authors are scientists who work for Eli Lilly. The research from both trials was published in the New England Journal of Medicine.












