Eli Lilly has released detailed results from the SURMOUNT-1 phase 3 trial, where over 1,000 obese or overweight prediabetic participants were followed over the course of 176 weeks, making it the longest study to date of tirzepatide.
The data shows that weekly injections of tirzepatide significantly reduced the risk of progression from pre-diabetes to type 2 diabetes compared with a placebo. Over the course of the 176 weeks, patients treated with the highest dose of tirzepatide achieved an average weight loss of 22.9%. These results have been published in The New England Journal of Medicine.
"Individuals treated with tirzepatide lost on average up to 23% of their body weight and maintained this for over three years, while benefiting from a substantial decrease in risk of developing type 2 diabetes. In absolute terms, nearly 99% of individuals treated with tirzepatide remained diabetes-free at 176 weeks," said Ania Jastreboff, director of the Yale Obesity Research Center. "These results are impressive given the degree of sustained weight reduction and decrease in risk of diabetes."
Tirzepatide is the active compound in Zepbound and Mounjaro, which are approved in the US as treatments for chronic weight management and type 2 diabetes, respectively. Drugs that target the glucagon-like peptide-1 (GLP-1) receptor, such as Zepbound and Novo’s Ozempic, have recently seen their demand explode due to their success in weight loss indications.
Among a growing number of competitors, tirzepatide is the first and so far the only approved dual GIP (glucose-dependent insulinotropic polypeptyde) and GLP-1 receptor agonist drug. Both GIP and GLP-1 are involved in regulating appetite.
The approval of Zepbound in November last year was supported by earlier results from the SURMOUNT-1 trial at 72 weeks of treatment. The long-term data at the 176 week timepoint comes from prediabetic patients that continued treatment after those initial 72 weeks, providing additional insights into the benefits of tirzepatide in not just treating but also preventing the progression of type 2 diabetes.
"In the SURMOUNT-1 three-year study of tirzepatide, an average weight reduction of up to 22.9% was accompanied by a hazard ratio of 0.06 for progression to type 2 diabetes. This translates to a risk reduction of 94%," said Jeff Emmick, senior vice president of product development at Eli Lilly. "These results underscore the critical role of long-term therapy with effective treatments like tirzepatide to achieve and maintain weight reduction."