Impact of lemborexant on daytime ratings of sleepiness/alertness in subjects with insomnia disorder and baseline sleepiness

Abstract Introduction Since the use of sleep-promoting drugs can also lead to residual morning sleepiness, it is important to determine if a new hypnotic is associated with such a carryover effect of treatment. To this end, an assessment of sleepiness/alertness was included in lemborexant (LEM) phase 3 studies. LEM is a competitive dual orexin receptor antagonist approved in several countries for the treatment of adults with insomnia. This post-hoc analysis of Study 304 (E2006-G000-304; NCT02783729) assessed the impact of LEM on morning sleepiness/alertness in subjects who reported at least mild/moderate morning sleepiness at baseline. Methods Study 304 was a randomized controlled study in adults ≥55y with insomnia disorder (N=1006). Subjects received bedtime doses of placebo (PBO), LEM 5mg (LEM5), LEM 10mg (LEM10), or zolpidem tartrate extended release 6.25 mg (not reported here) for 1 month. A daily Sleep Diary assessed morning sleepiness, within 90 min of waketime, with the question “How alert/sleepy do you feel this morning?” rated from 1 (extremely sleepy) to 9 (extremely alert). Scores were averaged over 7-day periods for baseline (single-blind run-in) and first and last 7 days of treatment. Chi-square tests were used to compare the shift from sleepy (≤3) to more alert (>3) between PBO and treatment groups. Results At baseline, 59/203 (29.1%), 66/261 (25.3%), and 79/265 (29.8%) of the PBO, LEM5, and LEM10 subjects reported a score ≤3, indicating at least mild/moderate morning sleepiness. At the end of 1 month of treatment, 37/57 (64.9%) of the PBO subjects rated themselves as less sleepy and more alert (>3), compared with 50/64 (78.1%; P=0.11) LEM5- and 58/76 (76.3%; P=0.15) LEM10-treated subjects. Conclusion In this study, ~28% of subjects reported morning sleepiness at baseline. More subjects who reported sleepiness at baseline and received LEM reported improved morning alertness during the last week of treatment compared with PBO subjects. These data are concordant with previous findings of a lack of effect of LEM on tasks requiring alertness in the morning. Support (if any) Eisai Inc.