The US Food and Drug Administration today approved a new indication for Xywav for idiopathic hypersomnia (IH) in adults. IH is an uncommon chronic sleep disorder that causes people to be excessively sleepy during the day even after a good night’s sleep. Xywav (calcium, magnesium, potassium, and sodium oxybates) oral solution is already approved for the treatment of cataplexy or excessive daytime sleepiness in patients seven years or older with narcolepsy.
“A novel indication for Xywav is significant as the FDA has never granted an approval for idiopathic hypersomnia,” said Eric Bastings, M.D., deputy director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research. “Idiopathic hypersomnia is a life-long condition, and the approval of Xywav will be instrumental in providing treatment for symptoms such as excessive sleepiness and difficulty waking, and in effectively managing this debilitating disorder.”
The effectiveness of Xywav was evaluated in a double-blind placebo-controlled randomized-withdrawal study in 154 adult patients (ages 19 to 75 years) with IH. In the clinical study, patients who were randomized to switch from Xywav to placebo experienced worsening on measures of sleepiness and symptoms of IH compared to patients randomized to continue treatment with Xywav.
In the clinical trial for IH, the most common adverse events as a result of the treatment observed in the study included nausea (21.4%), headache (16.2%), dizziness (11.7%), anxiety (10.4%) and vomiting (10.4%).
Xywav has a boxed warning for central nervous system depression and abuse and misuse. The active moiety of Xywav is oxybate, also known as gamma-hydroxybutyrate (GHB), a Schedule I controlled substance. Abuse or misuse of illicit GHB has been associated with serious side effects including seizures, trouble breathing, changes in alertness, coma, and death. Clinically significant respiratory depression and reduced level of alertness has occurred in adult patients taking sodium oxybate.
Because of the potential risks associated with Xywav, it is subject to strict safety controls on prescribing and dispensing under a program called a Risk Evaluation and Mitigation Strategy (REMS). Specifically, under the Xywav REMS, it can be prescribed only by a certified prescriber, and dispensed only to an enrolled patient by a certified pharmacy. Only a certified pharmacy that ships directly to patients can dispense Xywav. Xywav will not be available in retail pharmacies.