O030 Impact of lemborexant on daytime sleepiness/alertness in participants with comorbid insomnia and mild obstructive sleep apnea

Abstract Introduction Comorbid insomnia with obstructive sleep apnea (COMISA) is associated with daytime functioning and cognitive impairments. Some sleep-promoting medications cause residual morning sleepiness, potentially exacerbating daytime impairment. This post-hoc analysis assessed the impact of lemborexant (LEM), a competitive dual orexin-receptor antagonist approved to treat insomnia in adults, on morning sleepiness/alertness in participants with COMISA. Methods Data from a subgroup of adults (≥55 years) with comorbid insomnia and mild OSA (apnea-hypopnea-index, 5 to ≤15 events/h) from Study E2006-G000-304 (NCT02783729), a 1-month, randomized study, were analyzed (N=410). Participants received placebo (PBO), LEM 5mg (LEM5), LEM 10mg (LEM10), or zolpidem tartrate 6.25mg (not reported). A daily sleep diary assessed morning sleepiness/alertness rated from 1 (extremely sleepy) to 9 (extremely alert). The percentage of participants shifting from baseline mild/moderate sleepiness (≤3) towards greater alertness (4, 5, or >5) during the first and last 7 mornings of the study was analyzed. Results At baseline, 17/75 (22.7%), 36/112 (32.1%), and 28/104 (26.9%) participants with COMISA receiving PBO, LEM5, or LEM10, respectively, reported mild/moderate sleepiness. Of these participants, a greater percentage shifted from mild/moderate sleepiness towards alertness with LEM5 (66.7%, 82.9%) and LEM10 (64.3%, 75.0%) versus PBO (47.1%, 64.7%) across the first and last 7 mornings, respectively. Discussion The sample size was too small to detect statistical differences; however, a greater percentage of participants with COMISA experienced improvements in morning sleepiness across the treatment period with LEM versus PBO. These data align with previous findings that LEM does not affect tasks requiring morning alertness.