23 May 2013 - 23 May 2013 - US FDA's Peripheral and Central Nervous System Drugs Advisory Committee said Wednesday that it had supported the approval of Merck & Co's (NYSE:MRK) drug suvorexant for the treatment of insomnia, at lower doses.

Suvorexant is a highly selective antagonist for orexin receptors OX1R and OX2R that transiently inhibits the effects of wakefulness-promoting orexin neurons of the arousal system thus facilitating the natural transition from wake to sleep. Merck has recommended once-daily dose of 40 mg for non-elderly patients, or 20 mg per day based on a patient's in individual tolerability. For elderly patients, the manufacturer has recommended a daily dose of 30 mg or 15 mg per day, based on the individual tolerability.

The efficacy, safety and tolerability of suvorexant were examined when received in doses of 10 mg, 15 mg, 20 mg, 30 mg, 40 mg or 80 mg in numerous placebo-controlled trials for periods of up to 12 months.

The committee voted that the medicine is safe at 15 mg and 20 mg, but not at doses of 30 mg and 40 mg. The panel also noted that suvorexant fulfils an unmet medical need as a therapy of insomnia and has significant efficacy in the treatment of sleep onset and sleep maintenance insomnia. Furthermore, the product enhances clinically relevant measures, such as insomnia severity and improvement, perceived quality of life, functioning and stress due to insomnia as assessed by the Insomnia Severity Index.

The FDA is to take into consideration the advisory committee's stance for its final ruling.