Subjects with Insomnia Disorder and Comorbid Pain at Baseline: Response to Lemborexant

Abstract: Introduction: There is a well-established reciprocal relationship between pain and poor sleep. Therefore, it is clinically important to evaluate whether a sleep-promoting drug such as lemborexant (LEM; approved in multiple countries to treat adults with insomnia) can improve sleep in older adults in whom insomnia and ongoing pain are prevalent. Methods: Study 304 (NCT02783729) was a 1-month, double-blind, placebo (PBO)- and active-controlled study in subjects (age≥55y) with insomnia disorder (Full Analysis Set [FAS]=1006). Those reporting some/severe pain at baseline on the pain/discomfort dimension of the EuroQual-5 Dimension-3 Level scale were eligible for post-hoc analyses. Subjects were randomized to PBO, LEM 5mg (LEM5) or 10mg (LEM10) or zolpidem (not reported here). Changes from baseline (CFB) in objective sleep parameters (decreases from baseline indicate improvement), latency-to-persistent sleep (LPS), and wake-after-sleep onset (WASO) were analyzed in pairs of polysomnograms. Results: At baseline, ~18% of the FAS reported some/extreme pain (PBO=55; LEM5=78; LEM10=50) with median LPS (minutes)=31.0, 29.4, and 42.1 for PBO, LEM5, LEM10, respectively. Median CFB for LPS at the beginning (Nights 1/2: +2.5; –8.4, –15.8; P