The multicenter randomized double-blind placebo-controlled Phase III studies evaluated Suvorexant compared to placebo in adult patients aged 18 years and older.
In the trials, the primary endpoint was change from baseline in subjective total sleep time and time to sleep onset, wake time after persistent sleep onset, and latency to onset of persistent sleep at one and three months.
Based on the positive results from the two pivotal Phase III efficacy trials of Suvorexant, Merck plans to file a New Drug Application (NDA) with the US Food and Drug Administration (FDA) in 2012.
Merck Research Laboratories president Peter S Kim said Suvorexant selectively targets a crucial pathway involved in promoting sleep.
"We are enthusiastic about the potential of this investigational medicine, and look forward to sharing the results from these studies with the medical community," Kim added.