GLP-1 drug shows promise for youths with Type 2 diabetes

A phase 2 trial found that tirzepatide, the active ingredient in Lilly’s Zepbound and Mounjaro, can substantially improve blood-sugar control and reduce body weight in children as young as 10 with obesity and Type 2 diabetes. Over 30 weeks, participants receiving the drug showed large improvements in key diabetes and weight metrics compared with a placebo, with effects that extended through a full year of follow-up in the study.

The trial enrolled 99 patients between the ages of 10 and 17 who had obesity and Type 2 diabetes that remained poorly controlled despite treatment with metformin and/or insulin. Participants were randomly assigned to receive tirzepatide at 5 milligrams or 10 mg, or a placebo, once weekly for 30 weeks. By the end of the study period, those treated with tirzepatide achieved an average reduction in A1C of 2.2 percentage points, versus a 0.05-point drop in the placebo group. A target of 6.5% or lower—considered below the diabetes range—was reached by 71% of the 5 mg cohort and 86% of the 10 mg cohort, compared with 28% of those on placebo. In addition, body-mass-index (BMI) reductions were 7.4% for the 5 mg group and 11.2% for the 10 mg group, versus a 0.4% reduction with placebo. The study started from a baseline BMI average of 35.5, placing participants in the obese category. The benefits to both A1C and BMI persisted through 52 weeks and showed no signs of plateauing.

“ Tirzepatide is the first drug used for Type 2 diabetes in this age group that has shown sustained clinically-meaningful, BMI-lowering effects,” the study authors wrote. The drug’s safety profile in the trial was similar to that seen in adults, with the most common adverse effects being mild-to-moderate gastrointestinal issues that generally diminished over time. Two patients on the 5 mg dose discontinued treatment due to adverse events.

Dr. Tamara Hannon, director of the Clinical Diabetes Program at Indiana University and the trial’s lead investigator, said, “Youth living with Type 2 diabetes often face a more aggressive disease course, and in many instances, first-line treatments like metformin and basal insulin fail to control their A1C adequately. These results offer a promising opportunity to help shift the long-term health trajectory for young people living with this complex condition.”

Lilly has submitted the trial results to global regulators, seeking to expand Mounjaro’s approval to include younger patients. Regulators are watching for evidence that benefits in adolescents translate to longer-term health outcomes and safety beyond adulthood. In its current approvals, the U.S. Food and Drug Administration has approved three GLP-1 drugs for treating Type 2 diabetes in patients aged 10 and older, and two GLP-1 drugs for obesity in people aged 12 through 17.

The findings come as Type 2 diabetes and obesity among children and adolescents in the United States show signs of rising momentum. CDC data show that in 2002, nine of every 100,000 young Americans were diagnosed with Type 2 diabetes. By 2018, that rate had roughly doubled to 18 per 100,000. If the trajectory continues, government estimates project the number of youths with the disease could climb from about 28,000 in 2017 to roughly 220,000 by 2060. Double-digit increases in pediatric obesity have accompanied the diabetes surge, underscoring the urgency of broadening treatment options for younger patients.

The trial’s sponsors highlighted the potential implications of expanding access to GLP-1 therapies for younger people, noting that early and effective treatment could alter disease progression and long-term health outcomes. Lilly Cardiometabolic Health executives emphasized that the research aims to address an underserved patient population and to provide clinicians with new tools to manage a condition that often takes a more aggressive course in youth.

In addition to the promising efficacy signals, researchers stressed that careful monitoring of adverse events remains essential as approvals extend to younger ages. The most common side effects—gastrointestinal symptoms—tended to lessen with time, and there were few discontinuations overall. The investigators noted that longer-term studies will be needed to confirm durability of benefit, safety, and any potential impact on growth and development in children.

From a policy and access perspective, the ongoing development of tirzepatide for youths could influence insurance coverage, pediatric diabetes care guidelines, and the pace at which clinicians discuss GLP-1 therapies with families. Should regulators grant approval for younger patients, clinicians would need to navigate dosing strategies and monitoring requirements tailored to pediatric patients, as well as considerations around supply and cost.

The study adds to a broader conversation about personalized and age-appropriate treatments for pediatric Type 2 diabetes, a condition historically treated with lifestyle changes and metformin before insulin therapy. If the results hold in larger, longer-term studies, tirzepatide could become part of a risk-reduction strategy that aims to minimize diabetes-related complications over a lifetime. As Lilly continues conversations with regulators, patients, families and clinicians will be watching closely for the path forward on access for younger patients.

As the company and regulators weigh the benefits against potential risks in younger populations, this line of therapy could represent a turning point in pediatric diabetes care. If approved, it would broaden the toolkit available to physicians and could help many children and adolescents with Type 2 diabetes and obesity take a more proactive approach to managing their condition over the long term.