The U.S. Food and Drug Administration has approved Hetlioz (tasimelteon), a melatonin receptor agonist, to treat non-24- hour sleep-wake disorder ("non-24") in totally blind individuals. Non-24 is a chronic circadian rhythm (body clock) disorder in the blind that causes problems with the timing of sleep. This is the first FDA approval of a treatment for the disorder.
Non-24 occurs in persons who are completely blind. Light does not enter their eyes and they cannot synchronize their body clock to the 24-hour light-dark cycle.
Those with the disorder may have difficulty falling asleep or staying asleep, and may wake up groggy or feeling as if they need more rest. People with non-24 may find their sleep patterns reversed - needing to sleep during the day and to be awake at night.
"Non-24- hour sleep-wake disorder can prevent blind individuals from following the normal daily schedule that we all take for granted," said Eric Bastings, M.D, deputy director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research. "Hetlioz can improve the ability to sleep at night and to be active during the day."
Although most people who are totally blind still can perceive light well enough to prevent non-24, there may be as many as 100,000 individuals in the United States with this condition, who can't perceive enough light to establish a normal night sleep schedule. Non-24 can occur at any age.
The effectiveness of Hetlioz was evaluated in 104 participants in two clinical trials of totally blind individuals with non-24 disorder. In the trials, treatment with Hetlioz resulted in significant improvement compared to placebo (inactive pill), both in increasing nighttime sleep and decreasing daytime sleep duration.
In clinical trials, the most common side effects reported by patients treated with Hetlioz were headache, elevated liver enzymes (alanine aminotransferase) in the blood, nightmares or unusual dreams, disturbed night's sleep, upper respiratory or urinary tract infection, and drowsiness.
Hetlioz can impair activities that require complete mental alertness. Hetlioz should be taken at the same time every night before bedtime and activities should be limited after taking the drug.
Hetlioz was reviewed under priority review. Priority review provides for an expedited review of drugs that treat serious conditions and have the potential to provide significant improvement in safety or effectiveness of the treatment, diagnosis, or prevention of such serious conditions. Hetlioz also received orphan-product designation by the FDA because it is intended to treat a rare disease or condition.
Hetlioz is manufactured by Vanda Pharmaceuticals, Inc. of Washington, D.C.