Novo Nordisk says semaglutide helped 40% of children in trial leave obesity range, as shares slip

On September 7, 2026, Novo Nordisk reported that once-weekly semaglutide helped 40.4% of children aged 6 to under 12 in its phase 3 STEP Young trial move below the study's obesity classification after 68 weeks. No children taking placebo did. The company's shares closed 1.92% lower at $46.60 that day, with after-hours trading at $46.55 ^[1].

What the trial measured

STEP Young enrolled 165 children in a randomized, double-blind, placebo-controlled trial across multiple countries. All participants received a reduced-calorie diet and increased physical activity alongside either semaglutide or placebo ^[1]. Dosing was weight-based, with maximum semaglutide doses of 1.7 mg or 2.4 mg in the trial ^[1].

The primary endpoint was the percentage change in BMI from baseline through week 68, and semaglutide produced a greater reduction than placebo ^[1]. At week 68, 40.4% of treated children no longer met the study's obesity classification, versus 0% of the placebo group ^[1][2]. More than 85% of participants had class II or class III obesity when they started ^[1][2]. Researchers classified the children using CDC age-specific and sex-specific BMI growth charts ^[1].

Other endpoints covered cardiovascular risk factors, glucose metabolism, body measurements and body composition ^[1]. Novo Nordisk said safety and tolerability matched earlier semaglutide and liraglutide studies, and that no new safety concerns emerged, including none involving growth or pubertal development ^[1]. The trial was designed to meet post-marketing requirements for the company's semaglutide program ^[1].

Business context

The stock report and an investment write-up describe different trading days and prices. NVO closed at $46.60, down 1.92%, on the day of the announcement ^[1]. A Motley Fool article dated September 11 listed NVO at $43.07, down 2.14% that day ^[2].

That analysis said a pediatric approval "won't, by itself, be a game changer for Novo Nordisk," but could "help slightly move the needle," calling it one part of a broader effort to regain share in GLP-1s ^[2]. The article noted Novo has lost market share to Eli Lilly, whose Zepbound does not have an indication for children aged 6 to 11 ^[2]. Wegovy is approved for chronic weight management in adults and in pediatric patients aged 12 and older ^[2]. The Motley Fool estimated a US addressable market of about four million children aged 6 to 11, based on a CDC figure that 22.1% of children in that age range were obese between August 2021 and August 2023 ^[2].

Novo Nordisk has not disclosed whether or when it will seek FDA approval for children aged 6 to 11, and no such approval has been reported.

Why it matters for patients

Families of children aged 6 to 11 with severe obesity have had no approved GLP-1 option for chronic weight management; the current pediatric approval for Wegovy starts at age 12 ^[2]. These results are the first phase 3 data reported for semaglutide in the younger group, but they are trial results, not an approval, and access depends on a regulatory decision that has not been announced.

The trial measured a change in BMI classification at 68 weeks, not long-term health outcomes such as diabetes or heart disease. Whether children keep the weight off after stopping treatment has not been reported, and the results reflect medication combined with diet and activity changes rather than either alone ^[1].

Childhood obesity is common and often continues into adulthood ^[1][2]. Global estimates counted 177 million children aged 5 to 19 living with obesity in 2025, a figure projected to reach 228 million by 2040 ^[1].

What happens next

Novo Nordisk will present detailed STEP Young results at ObesityWeek 2026 in Washington from November 14 through November 17 ^[1]. Any filing for an expanded pediatric indication, and any FDA decision, has not been reported.