Once-Nightly Oxybate Formulation Effective and Preferred by People With Narcolepsy
Post hoc analysis of data from the pivotal phase 3 REST-ON trial showed a once-nightly formulation of sodium oxybate (ON-SXB)(FT218; Avadel Pharmaceuticals, Dublin, Ireland), reduced weekly cataplexy attacks and improved sleep latency compared with placebo.
Among participants who received ON-SXB vs placebo the average sleep latency change from baseline ranged from 5 to 30 minutes as measured by the Maintenance of Wakefulness Test. Improvements began as early as the third week of treatment and were dose-dependent.
Participants treated with ON-SXB were also more likely to have 25%, 50%, and 75% reductions in the number of weekly cataplexy episodes. For those who took the 6 or 7.5 g ON-SXB, 10% had complete elimination of their cataplexy, half had a 50% reduction, and one-third had a 75% reduction in their weekly cataplexy episodes
“The new post-hoc responder analyses demonstrating that ON-SXB improved EDS provide further confidence in ON-SXB for people with narcolepsy. We believe this is critical for a patient population whose quality of life is severely impacted by EDS,” said John Winkelman, MD, PhD, presenting author, professor of Psychiatry at Harvard Medical School and chief of the Sleep Disorders Clinical Research Program in the Department of Psychiatry at Massachusetts General Hospital. “These ON-SXB data represent a compelling way to set expectations for patients receiving therapy. I believe that ON-SXB, a once-nightly treatment option that has demonstrated clinical benefit in a randomized controlled trial, is a meaningful advance in treatment and, if approved, will be a welcome option for patients and physicians alike.”
In a discrete-choice study, dosing frequency was determined as the most important attribute of a narcolepsy treatment, with once-nightly dosing preferred (P<0.001).Once-nightly doses were the most important driver observed of “taking the medication exactly as directed” and “reduced anxiety/stress” as well.
The most common adverse reactions (≥5%) with ON-SXB 9-g were enuresis (9.1%), dizziness (5.2%), and vomiting (5.2%)
ON-SXB is an investigational formulation of sodium oxybate designed to be taken once a night for the treatment of excessive daytime sleepiness (EDS) or cataplexy in adults and is currently under review at the Food and Drug Administration (FDA). These post-hoc data were presented at the American College of Chest Physicians (CHEST) annual meeting, online October 17- 20, 2021.