Novo Nordisk’s phase 3 STEP Young trial found that 40.4% of children aged 6 to under 12 treated with once-weekly semaglutide were no longer classified as having obesity after 68 weeks, compared with none receiving placebo. All participants also followed a reduced-calorie diet and increased physical activity. The trial met its primary endpoint, with semaglutide producing a greater reduction in body mass index than placebo. The company reported no new safety concerns, including for growth or pubertal development, and said overall safety and tolerability were consistent with earlier semaglutide and liraglutide studies. Novo Nordisk shares closed at $46.60, down 1.92%, and slipped to $46.55 in after-hours trading. The company will present detailed results at ObesityWeek 2026 in Washington from November 14 through November 17. The findings come as prescriptions for GLP-1 weight-loss drugs among U.S. children under 12 have risen more than 300-fold since 2019, despite the medicines not being approved for that age group.