A phase 2 trial evaluating polysomnography outcomes and safety of lemborexant in Korean adults with insomnia disorder

Lemborexant (LEM), a dual-orexin-receptor-antagonist, was evaluated in this study of Korean participants with insomnia disorder. Study E2006-J082-204 (Study 204), a 1-month, multicenter, double-blind, placebo (PBO)-controlled, parallel-group study, evaluated LEM 5 mg (LEM5) or LEM 10 mg (LEM10) in participants aged 19–80 years with insomnia disorder (sleep efficiency [SE] ≤ 85%; latency to persistent sleep [LPS] ≥ 30 min). Korean participants were randomized (2:2:1) to LEM5, LEM10, or PBO, respectively, and received study drug immediately before bedtime for 30 days. Polysomnograms were conducted during an ~ 14-day single-blind PBO run-in (baseline) and after 1 month (Day 30). Changes from baseline in LPS (min; log-transformed; primary endpoint [LEM5 only]; secondary endpoint [LEM10 only]), SE (%; secondary endpoint), wake after sleep onset (WASO; min; exploratory endpoint), and total sleep time (TST; min; exploratory endpoint) were evaluated. Safety data were collected. The full analysis set comprised 64 participants (PBO, n = 13; LEM5, n = 25; LEM10, n = 26). At Day 30, decreases (improvements) from baseline in LPS and WASO were larger with LEM versus PBO. Increases from baseline in SE and TST were larger with LEM versus PBO. LEM was well tolerated. These findings support the clinical applicability of LEM as a therapeutic option for insomnia management in South Korea. Trial Registration E2006-J082-204: A study to assess the pharmacodynamics of lemborexant in Korean participants with insomnia disorder. https://clinicaltrials.gov/study/NCT05594589. ClinicalTrials.gov NCT05594589, October 21, 2022.