Novo Nordisk STEP Young Trial Shows Semaglutide Helped 40% of Kids

Novo Nordisk's phase 3 STEP Young trial demonstrated that once-weekly semaglutide combined with lifestyle modifications helped 40.4% of children aged 6 to under 12 drop below the obesity threshold after 68 weeks. The clinical trial compared the pharmacological treatment against a placebo group, tracking body mass index changes among young participants with severe baseline conditions.

"Childhood obesity is particularly concerning due to both immediate and enduring impacts on health, including a strong predilection to adult obesity and increased risk for the early emergence of obesity-related complications," said Ania M. Jastreboff, MD, PhD, Professor of Medicine (Endocrinology) and Pediatrics (Pediatric Endocrinology) at Yale and Director of the Yale Obesity Research Center (Y-Weight), in a statement regarding the results.

Trial Design and Patient Demographics

The STEP Young trial enrolled 165 children aged 6 to under 12 years diagnosed with obesity. According to baseline measurements from the study, over 85% of the young participants presented with class II or class III severe obesity prior to receiving treatment.

Participants in the active treatment arm received weight-based doses up to 1.7 mg or 2.4 mg of semaglutide weekly. This pharmacological regimen was administered alongside structured lifestyle modifications, which included a reduced-calorie diet and increased physical activity.

Comparative Results at Week 68

At the conclusion of the 68-week trial period, 40.4% of children receiving semaglutide successfully lowered their body mass index to a level no longer classified as obesity. In contrast, 0% of the children receiving the placebo achieved the same threshold reduction.

"For children living with obesity and their families, health challenges can begin early and affect wellbeing throughout life," said Martin Holst Lange, executive vice president, chief scientific officer and head of Research & Development at Novo Nordisk.

Broader Clinical Implications

Pediatric obesity treatments face rigorous clinical evaluation due to the long-term metabolic consequences associated with early-onset excess weight. The data from the STEP Young trial address a younger demographic than typical adolescent obesity studies, providing healthcare providers with clinical metrics for children under 12.

Detailed findings from the STEP Young phase 3 evaluation are scheduled for presentation at ObesityWeek 2026, The Obesity Society's annual meeting taking place from November 14 to November 17, 2026, in Washington, DC.