In a Phase 3 study, Eli Lilly’s tirzepatide led to a 94% reduction in the risk that obese or overweight prediabetes patients progress to type 2 diabetes. Lilly was already planning to expand use of the blockbuster metabolic disorders drug to sleep apnea and heart failure.

By Frank Vinluan The longest clinical trial to date for a blockbuster Eli Lilly metabolic disorder drug now has data showing the treatment delayed progression to type 2 diabetes in patients who are obese or overweight, results that continue to build the case of broader health benefits for the therapy.
The preliminary results announced Tuesday come from a clinical trial designed to test once-weekly injections of tirzepatide in prediabetes participants. In addition to being overweight or obese, participants also had at least one weight-related complication, excluding diabetes. The main goal of the placebo-controlled study is assessing tirzepatide’s effect on weight.
At the highest of three doses tested, participants experienced an average 22.9% loss of body weight versus 2.1% in the placebo group. But Lilly highlights results for a key secondary goal assessing the time to onset of diabetes progression. On this measure, Lilly said preliminary results from the more than three-year study show tirzepatide reduced the risk of progression to type 2 diabetes by 94% compared to a placebo. Indianapolis-based Lilly said detailed results will be submitted to a peer-reviewed journal and presented at the ObesityWeek 2024 conference in November.
“Obesity is a chronic disease that puts nearly 900 million adults worldwide at an increased risk of other complications such as type 2 diabetes,” Jeff Emmick, Lilly’s senior vice president, product development, said in a prepared statement. “Tirzepatide reduced the risk of developing type 2 diabetes by 94% and resulted in sustained weight loss over the three-year treatment period.”
Tirzepatide is the main pharmaceutical ingredient in Mounjaro, approved for type 2 diabetes, and Zepbound, approved for chronic weight management. The engineered peptide is designed to bind to and activate two receptors, GLP-1 and GIP, leading to a range of metabolic effects. The latest Phase 3 study is designed to evaluate the drug as an adjunct to diet and exercise in prediabetes patients. A primary analysis from the 2,539-patient study was conducted at 72 weeks. These results were published in the New England Journal of Medicine in 2022. The results announced Tuesday are for 1,032 participants who were followed for an additional 104 weeks of treatment. Lilly said the most common adverse events were mild to moderate gastrointestinal problems, consistent with the primary analysis and with other tests of the drug.
Mounjaro has become Lilly’s biggest and fastest growing product, with nearly $4.9 billion in sales in the first half of this year, more than three times the product’s sales in the same period last year. Zepbound, approved in late 2023, tallied more than $1.7 billion in sales in the first half of this year. Lilly aims to broaden tirzepatide’s use to other indications. The company has already submitted data to the FDA and other global regulatory bodies seeking approval of drug for treating moderate-to-severe sleep apnea. Lilly plans to submit data later this year supporting use of the drug in heart failure with preserved ejection fraction.
The new data in prediabetes patients support the use of tirzepatide beyond weight loss alone, Leerink Partner analyst David Risinger wrote in a note to investors. But Leerink does not expect a formal indication for the drug for preventing the onset of type 2 diabetes. Even though the company incorporated robust American Diabetes Association prediabetes guidelines in its trial enrollment criteria, it’s unclear whether the company can file for an additional FDA approval for type 2 diabetes prevention, he said. Lilly investor relations told Risinger that “a prediabetes indication is a challenging needle to thread with the FDA.”
“We currently assume that the data is simply added to tirzepatide’s label; if [Lilly] is able to secure a formal indication it would represent material upside, in our view,” Risinger wrote.
Photo: Craig F. Walker/The Boston Globe, via Getty Images