The Food and Drug Administration’s new indication for liraglutide (Saxenda) for weight loss in adolescents with obesity, announced on Dec. 4, received welcome as a milestone for advancing a field that’s seen no new drug options since 2003 and boosted by 50% the list of agents indicated for weight loss in this age group.
Dr. Aaron S. Kelly
But liraglutide’s track record in adolescents in the key study published earlier in 2020 left some experts unconvinced that liraglutide’s modest effects would have much impact on blunting the expanding cohort of teens who are obese.
“Until now, we’ve had phentermine and orlistat with FDA approval” for adolescents with obesity, and phentermine’s label specifies only patients older than 16 years. “It’s important that the FDA deemed liraglutide’s benefits greater than its risks for adolescents,” said Aaron S. Kelly, PhD, leader of the 82-week, multicenter, randomized study of liraglutide in 251 adolescents with obesity that directly led to the FDA’s action.
“We have results from a strong, published randomized trial, and the green light from the FDA, and that should give clinicians reassurance and confidence to use liraglutide clinically,” said Dr. Kelly, professor of pediatrics and codirector of the Center for Pediatric Obesity Medicine at the University of Minnesota in Minneapolis.
An ‘unimpressive’ drop in BMI
Sonia Caprio, MD, had a more skeptical take on liraglutide’s role with its new indication: “Approval of higher-dose liraglutide is an improvement that reflects a willingness to accept adolescent obesity as a disease that needs treatment with pharmacological agents. However, the study, published in New England Journal of Medicine, was not impressive in terms of weight loss, and more importantly liraglutide was not associated with any significant changes in metabolic markers” such as insulin resistance, high-sensitivity C-reactive protein, lipoproteins and triglycerides, and hemoglobin A1c.
The observed average 5% drop in body mass index seen after a year on liraglutide treatment, compared with baseline and relative to no average change from baseline in the placebo arm, was “totally insufficient, and will not diminish any of the metabolic complications in youth with obesity,” commented Dr. Caprio, an endocrinologist and professor of pediatrics at Yale University in New Haven, Conn.
Results from the study led by Dr. Kelly also showed that liraglutide for 56 weeks cut BMI by 5% in 43% of patients, and by 10% in 26%, compared with respective rates of 19% and 8% among those in the placebo-control arm. He took a more expansive view of the potential benefits from weight loss of the caliber demonstrated by liraglutide in the study.
“In general, we wait too long with obesity in children; the earlier the intervention the better. A 3% or 4% reduction in BMI at 12 or 13 years old can pay big dividends down the road” when a typical adolescent trajectory of steadily rising weight can be flattened, he said in an interview.
Bariatric and metabolic surgery, although highly effective and usually safe, is seen by many clinicians, patients, and families as an “intervention of last resort,” and its very low level of uptake in adolescents bears witness to that reputation. It also creates an important niche for safe and effective drugs to fill as an adjunct to lifestyle changes, which are often ineffective when used by themselves. Liraglutide’s main mechanism for weight loss is depressing hunger, Dr. Kelly noted.