Clinical Profile of Suvorexant, a Novel Orexin Receptor Antagonist, for Treating Elderly Patients with Insomnia

January 12, 2017

This poster was presented at the 29th Annual U.S. Psychiatric & Mental Health Congress, held October 21-24, 2016, in San Antonio, Texas.

INTRODUCTION: The elderly constitute a large proportion of those with insomnia and have particular problems with sleep-maintenance. Hypnotic medications are frequently prescribed but there are concerns that the elderly may be more sensitive to adverse drug effects (e.g., falls) and/or show differential efficacy compared with non-elderly patients. Suvorexant is a first-in-class orexin receptor antagonist recently approved for treating insomnia at doses of 10-20mg. We evaluated its clinical profile in elderly patients.

DESIGN/METHODS: Pre-specified pooled efficacy-analysis of elderly data from two similar phase-3, randomized, double-blind, placebo-controlled, 3-month trials in elderly (≥65y) and non-elderly (18-64y) primary insomnia patients. Elderly patients received suvorexant 30mg or 15mg. Efficacy was assessed by patient-reported-outcomes (PRO), and by objective polysomnographic (PSG) endpoints in a subgroup of ~75% of patients. The pooled safety-analysis also included 3-month elderly data from a 1-year safety trial of 30mg.

RESULTS: Sample sizes for PRO endpoints were 30mg=313, 15mg=198, placebo=307. In elderly patients, suvorexant 30mg improved PRO and PSG measures of sleep-maintenance and sleep-onset compared to placebo at the earliest timepoints (Week-1 for PRO and Night-1 for PSG measures) and Month-3 (p<0.05). Results were similar for 15mg, except for the PRO and PSG onset measures at Month-3 (p=0.05 and p=0.09, respectively). Sample sizes for the safety-analysis were 30mg=627, 15mg=202, placebo=469. Suvorexant was generally well-tolerated with few discontinuations due to adverse-events (30mg=6.4%, 15mg=3.5%, placebo=5.5%). The most frequent adverse-event, somnolence (30mg=8.8%, 15mg=5.4%, placebo=3.2%), was generally transient and mild-to-moderate in intensity.

CONCLUSIONS: Suvorexant was effective and generally well-tolerated over 3-months in elderly insomnia patients. 

W. Joseph Herring, MD, PhD
Ellen Snyder, PhD
Duane Snavely, MA
Jill Hutzelmann, MS
Deborah Matzura-Wolfe, MS
Chris Lines, PhD
Lisa Gold, PhD
David Michelson, MD
Sponsoring Organization: 
Merck & Co., Inc.
Presented By: 
Chris Lines, PhD, Director, Merck & Co., Inc., Kenilworth, NJ
Sleep Disorders
PCN Topics: