Novo Nordisk Trial Shows Semaglutide Reduced Obesity in Over 40% of Children

Novo Nordisk (NYSE: NVO) announced on Monday that its STEP Young phase 3 trial for semaglutide in children with obesity met its primary endpoint. The study showed that a significant portion of younger children treated with the drug achieved a body mass index (BMI) below the clinical threshold for obesity after 68 weeks.

Key Trial Findings

The trial evaluated the efficacy of a once-weekly semaglutide injection against a placebo in 165 children aged 6 to under 12, with both groups also receiving lifestyle intervention counseling. The results demonstrated a stark contrast between the two groups.

• 40.4% of children in the semaglutide group achieved a BMI below the obesity threshold.
• None of the children in the placebo group reached the same outcome.

The trial successfully met its primary objective by showing a statistically superior reduction in BMI for children treated with semaglutide. Novo Nordisk noted that over 85% of the participants began the trial with class II or III severe obesity, underscoring the significance of the results.

Safety Profile and Expert Commentary

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The company reported that the safety and tolerability of semaglutide in this pediatric trial were consistent with previous studies in adults and adolescents. No new safety concerns were identified, and no issues were found related to growth or pubertal development.

"Most of the children in the STEP Young trial were classified as having severe (class II or III) obesity at baseline, yet treatment with semaglutide resulted in a BMI percentile category below the obesity threshold in approximately 40% of the children," said Ania M. Jastreboff, Professor of Medicine and Pediatrics at Yale and Director of the Yale Obesity Research Center, in a statement included in the company's release.

Market Context and Next Steps

These positive results position semaglutide as a potential treatment for a younger demographic, tapping into a large and growing market. An estimated 177 million children aged 5 to 19 were living with obesity in 2025, with that figure projected to climb to 228 million by 2040.

Novo Nordisk plans to present the detailed trial data at The Obesity Society’s annual meeting, ObesityWeek 2026, which is scheduled for November 14-17 in Washington D.C.