As expected, the US Food and Drug Administration has approved Vanda Pharmaceuticals' Hetlioz to treat non-24-hour sleep-wake disorder in the totally blind.

Non-24 affects the majority of the 80,000 totally blind people in the USA who lack the light sensitivity necessary to synchronise the body clock in the brain with the 24-hour day-night cycle. The approval comes after the agency's Peripheral and Central Nervous System Drugs Advisory Committee voted 10-0 in November, with one abstention, in terms of efficacy and voted unanimously that safety has been shown for Hetlioz (tasimelteon).

The effectiveness of the melatonin receptor agonist was evaluated in 104 participants in two trials of totally blind individuals with non-24 disorder. Treatment with Hetlioz resulted in significant improvement compared to placebo, both in increasing nighttime sleep and decreasing daytime sleep duration.

In the trials, the most common side effects were headache, elevated liver enzymes in the blood, nightmares or unusual dreams, disturbed night’s sleep, upper respiratory or urinary tract infection and drowsiness.

The approval comes after an FDA priority review and Hetlioz also received orphan-product designation. It will be launched in the second quarter.