Liraglutide lowered BMI in children aged 6 to under 12 in phase 3 trial

In a phase 3a trial, children aged 6 to under 12 with obesity who received once-daily liraglutide injections plus lifestyle interventions had a mean BMI change of −5.8% after 56 weeks, while children who received a placebo saw BMI rise by a mean of 1.6% ^[1]. The estimated difference between the groups was 7.4 percentage points (95% CI, −11.6 to −3.2; P<0.001) ^[1].

The trial, called SCALE Kids, randomly assigned 82 children in a 2:1 ratio — 56 to liraglutide and 26 to placebo — and was funded by Novo Nordisk ^[1]. Liraglutide, a GLP-1 receptor agonist, was given as a once-daily under-the-skin injection at 3.0 mg, or the highest dose each child could tolerate, alongside lifestyle interventions in both groups ^[1]. The treatment period ran 56 weeks and was followed by a 26-week follow-up period ^[1]. The main measure was the percentage change in BMI, calculated as weight in kilograms divided by the square of height in meters ^[1].

Two secondary measures also favored liraglutide. Mean body weight rose 1.6% in the liraglutide group and 10.0% in the placebo group, an estimated difference of 8.4 percentage points (95% CI, −13.4 to −3.3; P=0.001) ^[1]. And 46% of children on liraglutide reduced their BMI by at least 5%, compared with 9% on placebo (adjusted odds ratio, 6.3; 95% CI, 1.4 to 28.8; P=0.02) ^[1].

Side effects were common in both groups. Overall adverse events occurred in 89% of children taking liraglutide and 88% taking placebo ^[1]. Gastrointestinal adverse events were more frequent with liraglutide, reported in 80% versus 54% ^[1]. Serious adverse events were reported in 12% of the liraglutide group and 8% of the placebo group ^[1]. The published abstract does not describe what those serious events were.

The paper's background notes that no medication is currently approved to treat nonmonogenic, nonsyndromic obesity in children younger than 12 ^[1]. The results do not report any regulatory filing, approval or label change for liraglutide in this age group, and any such plans have not been disclosed in the paper ^[1].

Why it matters for patients

For families of children under 12 with obesity, there is no approved drug option, so care has centered on lifestyle interventions — the same interventions both groups received in this trial ^[1]. The results therefore describe liraglutide plus lifestyle support, not liraglutide alone ^[1].

The trial was small. With 82 children, the estimates carry wide uncertainty; the odds ratio for a 5% BMI reduction, for example, ranged from 1.4 to 28.8 across the confidence interval ^[1]. The abstract also does not say whether the BMI difference persisted after treatment stopped, even though the trial included a 26-week follow-up ^[1].

Gastrointestinal side effects were the clearest difference between groups, reported in 4 out of 5 children taking liraglutide, compared with about half of those taking placebo ^[1]. Nausea, vomiting, diarrhea and constipation are the kinds of events usually grouped in that category, but the abstract does not break them down.

What happens next

The New England Journal of Medicine published three comment letters on the trial, plus a reply from authors including C.K. Fox, N.M. Harder-Lauridsen and S. Arslanian, in its May 8, 2025 issue (volume 392, issue 18) ^[1]. No abstracts are available for those letters in this record, so their content is not summarized here ^[1].

The trial is registered as NCT04775082 ^[1]. Results from the 26-week follow-up period that ran after the 56 weeks of treatment have not been reported in the published abstract ^[1]. Whether Novo Nordisk has sought FDA approval for liraglutide in children under 12 has not been disclosed in the paper ^[1].