Novo Nordisk's STEP Young phase 3 trial met its primary endpoint, showing 40.4 percent of children aged 6 to under 12 with obesity achieved a BMI below the obesity threshold after 68 weeks of semaglutide treatment, versus none on placebo. The results support expanding the GLP-1 drug's label to younger pediatric populations and strengthen Novo Nordisk's competitive position against Eli Lilly in the obesity market.
Two out of every five children with obesity treated with semaglutide in Novo Nordisk's STEP Young trial were no longer classified as obese after 68 weeks, a result that clears a path toward pediatric label expansion for the Danish drugmaker's GLP-1 franchise.
"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 percent of the children within about a year of treatment," Ania M. Jastreboff, professor of medicine and pediatrics at Yale and director of the Yale Obesity Research Center, said.
The phase 3 trial enrolled 165 children aged 6 to under 12 with obesity, all receiving once-weekly subcutaneous semaglutide at a maximum dose of 1.7 mg or 2.4 mg based on baseline weight, alongside reduced-calorie diet and increased physical activity. More than 85 percent of participants had class II or III severe obesity at baseline, corresponding to a BMI at or above 35 and 40 in adults, respectively. The overall safety and tolerability profile was consistent with prior adult and adolescent semaglutide trials, with no new safety concerns identified for growth or pubertal development.
"For children living with obesity and their families, health challenges can begin early and affect wellbeing throughout life," Martin Holst Lange, executive vice president and chief scientific officer at Novo Nordisk, said. "As a pioneer in pediatric obesity medicine, we are encouraged by the positive STEP Young results and semaglutide's potential to help children living with obesity who need medical treatment, alongside lifestyle changes, to better manage their obesity."
The results extend Novo Nordisk's semaglutide franchise into younger pediatric populations, where clinically tested treatment options remain limited. An estimated 177 million children aged 5 to 19 were living with obesity in 2025, projected to rise to 228 million by 2040, according to the World Obesity Federation. Children with obesity face cardiovascular risk factors, depression, eating disorders, and bullying, with studies showing their quality of life is comparable to children undergoing cancer treatment. Without effective intervention, childhood obesity strongly tracks into adulthood, where complications emerge earlier and more severely.
The readout strengthens Novo Nordisk's competitive position against Eli Lilly in the GLP-1 obesity market, where both companies are expanding label indications across age groups. Semaglutide, marketed under the brands Wegovy, Ozempic, and Rybelsus, is already approved for adults and adolescents with obesity. Novo Nordisk said the trial was conducted as part of regulatory post-marketing requirements following phase 3 results in those populations. Detailed STEP Young results will be presented at ObesityWeek 2026 in Washington DC from Nov. 14-17.
For Novo Nordisk shareholders, the data supports the company's pediatric expansion thesis and could extend the commercial runway of the semaglutide franchise as adult-market competition intensifies. The next catalyst is the full data presentation at ObesityWeek in November, followed by regulatory submissions for pediatric label expansion.
This article is for informational purposes only and does not constitute investment advice.
