Eli Lilly to release late-stage data on next-generation weight loss drug retatrutide in 2025, earlier than expected

Eli Lilly on Thursday said it expects to release data from a late-stage trial on its next-generation weight loss drug retatrutide later this year, which is a few months earlier than anticipated. 

The company expects to read out results from a study in people with obesity and osteoarthritis of the knee in 2025, according to fourth-quarter earnings slides on its website. Eli Lilly previously said that phase three study was expected to finish in February of 2026. 

It is among at least nine closely watched clinical trials on retatrutide, which works differently from the obesity and diabetes treatments on the market and appears to be even more effective at weight loss. 

Retatrutide is a key part of Eli Lilly’s drug pipeline that could help the company maintain its dominance in the blockbuster weight loss and diabetes treatment space and gain an edge over key competitor Novo Nordisk. Dubbed the “triple G” drug, retatrutide works by mimicking three hunger-regulating hormones: GLP-1, GIP and glucagon. That appears to have more potent effects on a person’s appetite and satisfaction with food.

Meanwhile, tirzepatide – the active ingredient in Eli Lilly’s weight loss shot Zepbound and diabetes drug Mounjaro –mimics two hunger-regulating hormones, GLP-1 and GIP. Novo Nordisk’s weight loss drug Wegovy only mimics GLP-1.

The treatment also appears to cause even greater weight loss than tirzepatide, which has skyrocketed in demand in the U.S.

Retatrutide helped patients lose 24.2% of their body weight, or 58 pounds, on average after 48 weeks in a mid-stage trial on adults who were obese or overweight. Those who took the placebo lost 2.1% of their body weight after that same time period.

Higher doses of tirzepatide helped patients with obesity lose up to 22.5% weight loss on average in late-stage studies.

— CNBC’s Angelica Peebles contributed to this report.