May 19, 2023 -- Nearly half of teens given the weight loss drug semaglutide (Wegovy) managed to lose enough weight to drop below the clinical threshold for obesity, a new study shows.
By comparison, only 12.1% of adolescents with obesity given a placebo in the 68-week trial dropped below the threshold.
Semaglutide belongs to a class of drugs known as GLP-1s because they mimic the effects of glucagon-like peptide 1, a hormone made in the gut that helps people feel full.
The study, called STEP TEENS (Semaglutide Treatment Effect in People with Obesity), also shows that 74% of people in the study shifted down by at least one body mass index, or BMI, category after receiving a once-weekly injection of the drug compared to 19% of those on placebo.
“In a practical sense, we see that semaglutide reduced weight to a level below what is defined as clinical obesity in nearly 50% of the teens in our trial, which is historically unprecedented with treatments other than bariatric surgery," said Aaron Kelly, MD, co-director of the Center for Pediatric Obesity Medicine at the University of Minnesota in Minneapolis, who presented the latest data on Thursday at the European Congress on Obesity in Dublin, Ireland.
There was about a 23-fold higher chance of a teen dropping below the obesity threshold when using semaglutide, compared to placebo, he said.
This analysis, published in the journal Obesity on Wednesday, follows the publication last fall of the main results of the study in the New England Journal of Medicine, which showed semaglutide helps adolescents lose weight.
The drug was approved by the FDA in January for the treatment of obesity in those aged 12 and over.
Grace Malley, PhD, with the Child & Adolescent Obesity Service, Children's Health Ireland, in Dublin, said the teens' access to comprehensive health care is essential for the proper treatment of obesity.
"Treatment requires a long-term, multidisciplinary chronic-care approach, and usually when treatment stops, the biological mechanisms driving the obesity begin again to drive the buildup of [fatty] tissue,” she said. This means that “long-term treatment including nutrition therapy, exercise … behavioral support, and sleep therapy needs to be available to families in combination with pharmacotherapy and surgical intervention where required."
"The results of the STEP TEENS study represent a promising development for the treatment of adolescent obesity and for associated complications related to liver function," Malley said.
Exercise a Part of the Plan
In this newest analysis of the STEP TEENS trial, the authors examined the effect of semaglutide on moving 134 adolescents from one BMI category to another, including dropping below the obesity threshold into the overweight or normal weight category; 66 teens were given a placebo.
All participants also received nutritional counseling and a goal of 60 minutes of moderate- to high-intensity physical activity per day.
"After 68 weeks not a lot happened [in placebo participants], however, 12.1% of placebo participants did drop below the obesity threshold into overweight or normal-weight categories," said Kelly.
But referring to people on semaglutide, "a total of 45% of patients on semaglutide dropped below the clinical BMI cut point for obesity, such that 19.5% dropped into the overweight category and 25.4% reduced their BMI into the normal weight category," he said.
While not "statistically significant," Kelly pointed out that "females tended to respond better to semaglutide, likewise younger adolescents, and middle body weights tended to respond better to the drug, and there was a similar pattern with obesity classes."