Prime Highlights: 

Eli Lilly plans to release late-stage trial data for Retatrutide in 2025, ahead of the previous 2026 estimate. 

The study will focus on individuals with obesity and knee osteoarthritis over 68 weeks. 

Key Background: 

Eli Lilly & Co. has announced plans to release data from a late-stage trial of its next-generation weight loss drug, retatrutide, in 2025—several months earlier than previously expected. The company anticipates sharing results from a 68-week study involving individuals with obesity and knee osteoarthritis, with data set to be unveiled in 2025. Originally, Eli Lilly had projected the study would conclude in February 2026. 

Retatrutide, a significant component of Eli Lilly’s drug pipeline, represents a new class of treatments that may offer enhanced efficacy over existing weight loss therapies. The drug works by mimicking three hunger-regulating hormones—GLP-1, GIP, and glucagon—differentiating it from current obesity and diabetes treatments, which typically target only one or two of these hormones. The triple-hormone approach appears to produce more potent effects on appetite and satiety. 

According to Daniel Skovronsky, Eli Lilly’s chief scientific and medical officer, the company believes retatrutide could achieve greater weight loss results than its predecessor, tirzepatide, and potentially offer additional health benefits. Tirzepatide, the active ingredient in Eli Lilly’s weight loss injection Zepbound and diabetes medication Mounjaro, mimics GLP-1 and GIP. In comparison, Novo Nordisk’s weight loss drug Wegovy targets only GLP-1. 

In clinical trials, retatrutide has demonstrated promising results. In a mid-stage trial, patients lost an average of 24.2% of their body weight, or approximately 58 pounds, after 48 weeks, compared to just a 2.1% reduction in the placebo group. This level of weight loss surpasses the results seen with tirzepatide, which showed a 22.5% average weight loss in late-stage studies. As Eli Lilly continues to advance its weight loss and diabetes treatment pipeline, retatrutide positions the company to maintain its leadership in these markets, potentially gaining an edge over its key competitor, Novo Nordisk.