CHICAGO — The novel investigational sleep agent eplivanserin improves sleep continuity in patients with chronic primary insomnia without causing next-day drowsiness or rebound insomnia upon discontinuation, clinical trials show.
Eplivanserin's developer, Sanofi-Aventis, is gearing up for the European launch of the drug in 2009 based upon favorable comments from the European drug agency. In addition, the company, which has funded three completed phase III clinical trials, is preparing to file for marketing approval in the United States and Canada, Pierre Gervais said at the annual American Psychiatric Association Institute on Psychiatric Services.
Eplivanserin is the furthest along in development of a new nonsedating drug class known as ASTARs, or Antagonists of Serotonin Two A Receptors. Many sleep disorder experts expect the ASTARs to take over a major chunk of the insomnia treatment market now dominated by zolpidem and other drugs acting on the γ-aminobutyric acid-A receptor, according to Mr. Gervais, a pharmacist at Q&T Research of Sherbrooke, Quebec, an independent clinical research firm hired by Sanofi-Aventis to participate in an eplivanserin trial.
He reported on a trial involving 351 adults with chronic insomnia who were randomized double blind to 4 weeks of either 1 mg or 5 mg of eplivanserin or placebo in the evening. The 5-mg dose, which is what will be marketed, resulted in a self-reported mean 39-minute reduction in the baseline 84-minute wake time after sleep onset. This was significantly greater than the mean 26-minute reduction with placebo.
Also, eplivanserin at 5 mg/day resulted in a 64% reduction in the number of nocturnal awakenings, compared with a 36% decrease with placebo. More eplivanserin-treated patients reported a significant improvement in the refreshing quality of sleep.
The side effect profile of eplivanserin essentially mimicked that of placebo. The exception was dry mouth, which was reported by 1.7% of the placebo group and 5.3% of patients on 5 mg/day of eplivanserin. The ASTAR was not associated with any next-morning drowsiness or difficulty in concentration. Nor did rebound insomnia occur in the week after discontinuing 4 weeks of eplivanserin.