Substantial Weight-Loss, Pain Relief Seen In Trial Of Next-Gen Obesity Drug

Eli Lilly's latest drug, retatrutide, has demonstrated significant weight loss and pain relief in a Phase 3 trial. The study, which focused on adults with obesity and knee osteoarthritis, showed that patients who remained on the highest dose lost an average of 28.7% of their body weight over 68 weeks. When including all participants, the weight loss averaged 23.7%. The drug also reduced knee osteoarthritis pain by up to 62.6% on average, with more than one in eight patients experiencing complete pain relief by the end of the trial.

Eli Lilly is positioning retatrutide for individuals with severe obesity, as 84% of trial participants had a body mass index (BMI) over 35.

Despite its efficacy, the drug had a high discontinuation rate, with 18% of patients on the highest dose stopping treatment due to side effects, including nausea and dysesthesia. The discontinuation rates were linked to patients' starting BMI, with some stopping due to "perceived excessive weight loss."

Retatrutide works by mimicking three hunger-regulating hormones, GLP-1, GIP, and glucagon, offering more potent effects than existing treatments. Eli Lilly plans to conduct seven more trials by the end of 2026 to further assess the drug's potential.