EFFECTS OF SUVOREXANT ON SLEEP ARCHITECTURE IN PATIENTS WITH ALZHEIMER'S DISEASE AND INSOMNIA

Abstract Introduction Suvorexant, an orexin receptor antagonist that enables sleep to occur via competitive antagonism of wake-promoting orexins, improved total sleep time (TST) in a sleep laboratory polysomnography (PSG) study of patients with AD and insomnia. Here we report on the effects of suvorexant on sleep architecture in the study. Methods This was a randomized, double-blind, 4-week trial (ClinicalTrials.gov NCT02750306). Participants who met diagnostic criteria for both probable AD dementia (of mild to moderate severity) and insomnia were randomized to suvorexant 10mg (could be increased to 20mg based on clinical response) or matching placebo. Overnight sleep laboratory PSG was performed on 3 nights: screening, baseline, and Night-29 (last night of dosing). Suvorexant differences from placebo in changes-from-baseline at Night-29 for sleep architecture were analyzed as exploratory endpoints. Results A total of 274 participants were included in the analysis (suvorexant N=135, placebo N=139). At Night-29, suvorexant improved TST by 28 minutes versus placebo (p=0.001). There were no significant differences between suvorexant and placebo in the % of TST spent in REM (1.3%, 95% CI: -0.5, 3.0), N1 (0.6%, 95% CI: -1.2, 2.5), N2 (-1.0%, 95% CI: -3.2, 1.2), or N3 (-0.6%, 95% CI: -1.8, 0.6). There was no significant difference between suvorexant and placebo in latency to REM (-5.4 minutes, 95% CI: -23.4, 12.7). Conclusion Suvorexant improves TST without altering the underlying sleep architecture in AD patients with insomnia. Support Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA