The once-weekly injected drug, retatrutide, is part of a class known as incretins designed to mimic the action of the GLP-1 hormone, which helps regulate blood sugar, slow stomach emptying and decrease appetite. The new family of drugs has reignited interest in the weight-loss treatment market, which is estimated to reach $100 billion by the end of the decade.
Lilly's Mounjaro, which is awaiting U.S. regulatory approval for treatment of obesity, targets GLP-1 as well as a second obesity-related hormone called GIP. Retatrutide targets GLP-1, GIP and the body's receptors for a third hormone, glucagon.
Given the three targets, Lilly has nicknamed the drug triple G.
The company reported last year that a trial of Mounjaro in people who were obese or overweight found it led to weight loss of 22.5% after 72 weeks.
Lilly said the 338-person retatrutide study also showed that the drug helped improve blood pressure and blood sugar levels.
It said side effects were similar to those seen with other incretin-based therapies, including generally mild-to-moderate nausea and vomiting.
Lilly is conducting longer-duration phase 3 trials of retatrutide to see if weight loss might be further improved.
Those studies will evaluate the drug's safety and effectiveness for chronic weight management as well as obstructive sleep apnea and knee osteoarthritis.
“These phase 2 data have given us confidence to further explore the potential of retatrutide in phase 3 trials that will look beyond weight reduction and focus on treating obesity and its complications comprehensively,” Dan Skovronsky, Lilly's chief scientific and medical officer, said in a statement.
Results from the phase 2 trial were presented in San Diego at a meeting of the American Diabetes Association and published in the New England Journal of Medicine.
