Phase III results for Hetlioz (tasimelteon) in sleep disorders published in The Lancet-Vanda Pharmaceuticals

Vanda Pharmaceuticals has announced publication of pivotal trial results related to patient entrainment in the August issue of The Lancet. The results are from the SET and RESET Phase III studies of Hetlioz (tasimelteon), a circadian regulator for the treatment of individuals suffering from Non-24-hour sleep-wake disorder (Non-24). In the SET study, tasimelteon achieved the primary endpoints of entrainment of the melatonin rhythm as compared to placebo and clinical response as measured by entrainment plus a score of greater than or equal to 3 on the Non-24 Clinical Response Scale. Tasimelteon also demonstrated significant improvement versus placebo across a number of sleep and wake parameters including measures of total sleep time, daytime sleep duration, and timing of sleep, as well as in the Clinical Global Impression of Change, an overall global functioning scale. The RESET study demonstrated that continued treatment with 20mg of tasimelteon is required to maintain entrainment of the master body clock as measured by melatonin and cortisol circadian rhythms in individuals with Non-24.

Comment: Non-24 is a serious, rare and chronic circadian rhythm disorder that affects a majority of totally blind individuals who lack light perception, and consequently cannot entrain (synchronise) their master body clock to the 24-hour day. Tasimelteon is currently approved for use in the United States and in the European Union.