Merck has made public new data for suvorexant, the investigational medicine Merck is developing for the treatment of insomnia. The new data are from one of the longest, continuously dosed, placebo-controlled trials of a sleep medication ever conducted. This 12-month study was designed to assess the safety of suvorexant, while also evaluating its longer term efficacy. Merck presented new results from a 2-month discontinuation phase that followed the 12-month study at the 21st Congress of the European Sleep Research Society (ESRS).
“The methods used in this study allowed us to understand what happened when patients who had been taking suvorexant every night for a year were immediately switched to placebo, because what happens when patients stop taking a sleep medication is a key concern for both patients and healthcare professionals,” said James K. Walsh, PhD, executive director and senior scientist, Sleep Medicine and Research Center, St. Luke’s Hospital, and visiting professor, Department of Psychiatry, Stanford University School of Medicine. "We found that the patients who had been taking suvorexant for 12 months and were switched to placebo saw their insomnia return, but clinically meaningful withdrawal symptoms and rebound insomnia did not emerge. We also obtained efficacy data from patients who continued to take suvorexant through 14 months."
Specifically, results from the 2-month discontinuation phase showed that, after daily use of a consistent dose of suvorexant for 1 year, patients who stopped taking the medicine experienced a return of their sleeping difficulties to levels similar to those reported by patients who received placebo over the course of the trial. Patients who continued to receive suvorexant for the additional 2 months experienced mean improvements in their ability to fall asleep and stay asleep that were consistent with those seen over the first 12 months compared to placebo. Adverse experiences reported in the 2-month discontinuation phase were generally consistent with those reported during the 12-month study.
Merck plans to submit a New Drug Application (NDA) for suvorexant to the US Food and Drug Administration (FDA) in 2012. If approved, suvorexant would be the first in a new class of medicines, called orexin receptor antagonists, for use in patients with difficulty falling or staying asleep. Merck anticipates that suvorexant will be evaluated by the Controlled Substance Staff of the FDA.
“Suvorexant represents a new and different approach to treating insomnia, an area of significant unmet need,” said Darryle D. Schoepp, PhD, senior vice president and head of Neuroscience and Ophthalmology franchise, Merck Research Laboratories. “We are enthusiastic about the results of this long-term study, which provide important insights into suvorexant and the chronic nature of insomnia. Merck is continuing with plans to seek approval for suvorexant in the United States and in other countries around the world.”