Decrease sodium oxybate could end in weight reduction in adults with idiopathic hypersomnia

Lower sodium oxybate (Xywav), an agent approved by the U.S. Food and Drug Administration (FDA) to treat narcolepsy and idiopathic hypersomnia in adults, may also cause weight loss in overweight or obese patients.

A new Phase 3 study presented this week at the Associated Professional Sleep Societies (SLEEP) 2022 Annual Meeting showed that more than a quarter of patients with idiopathic hypersomnia treated with Jazz Pharmaceuticals’ therapy were within lost ≥ 5% weight by 16 weeks.

Led by Yves Dauvilliers, MD, PhD, Professor of Neurology and Physiology at the University of Montpellier in France, the international research team attempted to assess weight change during treatment with lower sodium oxybate in a phase 3 clinical setting.

“Treatment with sodium oxybate has been associated with weight loss in patients with narcolepsy,” they explained. “Lower sodium oxybate contains the same active moiety as sodium oxybate, with 92% less sodium, and is approved in the United States for the treatment of idiopathic hypersomnia in adults.”

The study participants were between 18 and 75 years old and suffered from idiopathic hypersomnia. They were either treatment-naïve or were taking a warning drug with or without lower sodium oxybate at baseline. They were stratified by weight status per baseline BMI.

Investigators initiated treatment with lower sodium oxybate over a 10- to 14-week, open-label, optimized treatment and titration period. After a 2-week stable dose phase with the optimized dose of the lower sodium oxybate, patients were randomized 1:1 to receive either treatment or placebo for an additional 2-week, double-blind, randomized withdrawal phase, then a 24-week open-label phase. label extension.

The study included 154 participants with an average age of 40.3 years. Mean baseline weight was 76.9 kg or approximately 169.5 lbs and mean baseline body mass index (BMI) was 27.1 kg/m2. Only 2 (1.3%) participants were underweight by BMI; 62 (40.3%) were of normal weight; 52 (33.8%) were overweight; and 38 (24.7%) were obese.

Dauvilliers and colleagues reported that 31 of 108 (28.7%) participants had ≥ 5% weight loss per body weight by the completion of the stable dose phase. Overall, the mean change in participant weight at the end of this period was -2.5 kg.

The researchers also observed that the mean decreases at the end of the dose-stable period were numerically larger in participants with higher baseline BMI; Participants with an overweight or obese BMI lost an average of 2.8 and 3.2 kg, respectively, while participants with a normal BMI only lost an average of 1.8 kg.

“In this Phase 3 clinical trial, adults with idiopathic hypersomnia treated with lower sodium oxybate experienced weight loss, including weight loss of ≥5% in 28.7% of participants,” the researchers concluded. “Mean weight loss was greater in participants with a higher baseline BMI.”

The study “Weight Changes During Treatment with Lower Sodium Oxybate in a Phase 3 Clinical Study in Patients with Idiopathic Hypersomnia” was presented at SLEEP 2022.