Novo Nordisk's blockbuster weight loss drug, Wegovy (semaglutide), has met its primary endpoint in a Phase III post-marketing study in children with obesity – highlighting the drug's potential to take younger patients under the obesity threshold when lifestyle modifications remain insufficient.

Through a Phase III interventional trial dubbed STEP Young (NCT05726227), the Danish pharma company compared either a 1.7mg or 2.4mg dose of Wegovy, alongside a reduced-calorie diet and increased physical activity, to placebo and the same lifestyle interventions in patients aged between six and up to 12 years old. Those in the treatment arms were allocated a dose based on their weight at the beginning of the study.

During the trial, patients given Wegovy experienced a superior reduction from baseline in BMI at week 68, with just over two in five treated individuals falling under the obesity threshold at this time point compared to zero in the placebo group – meeting the trial's primary endpoint.

Meanwhile, patients also tolerated Wegovy well in this trial, with no new safety concerns around growth, pubertal development or general adverse events (AEs) identified.

Novo Nordisk plans to share full details from the STEP Young study at ObesityWeek 2026, which will be held between 14-17 November in Washington DC.

Novo debuts new data on Wegovy in this population as researchers estimate that 177 million children between the ages of five and 19 were living with obesity in 2025 – with this figure set to rise to 228 million by 2040.

"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," commented Ania Jastreboff, director of the Yale Obesity Research Center.

By intervening in obesity earlier, Novo's EVP, CSO and head of R&D, Martin Holst Lange, claims that healthcare systems could potentially prevent serious health risks later in life, which can include an uptick in cardiovascular disease risk, among others.

Currently, the US Food and Drug Administration (FDA) has not approved Wegovy for use in children under 12, although this positive trial result could pave the way for the drug's potential label expansion for use in patients as young as six years old in the future.

This could give the medicine a potential edge over Eli Lilly's rival weight loss therapy, Zepbound (tirzepatide), which is currently only indicated for adults with obesity. While Lilly is conducting the SURMOUNT-ADOLESCENTS programme (NCT06439277; NCT06439277) exploring Zepbound's potential in adolescents aged between 12 and 17, it is not currently running any late-stage trials on the drug in the under-12 age group.

A leg up on Lilly would be welcome for Novo Nordisk, which has struggled with slowing sales growth for its weight loss franchise, as well as stiff competition from Lilly. This turbulence is further compounded by a range of late-stage trial failures – including that of its inflammation-targeting candidate, ziltivekimab, as well as the failure of its combination therapy, Cagrisema to best Zepbound in terms of weight loss.

GlobalData analysts currently forecast that Wegovy will see peak sales in 2028, with the drug generating over $13bn during the year.

GlobalData is the parent company of Clinical Trials Arena.

"Novo's Wegovy touts obesity-treating potential in patients as young as six" was originally created and published by Clinical Trials Arena, a GlobalData owned brand.