SAFETY AND EFFICACY OF LEMBOREXANT IN PATIENTS WITH INSOMNIA DISORDER: REPORT FROM A POST-MARKETING OBSERVATIONAL STUDY

Abstract Background The competitive dual orexin receptor antagonist lemborexant (LEM) has been available in Japan as a treatment for insomnia since July 2020. The most commonly reported adverse event (AE) in phase 3 studies was somnolence. A post-marketing observational study (E2006-M081-501) was conducted to examine the incidence of adverse drug reactions (ADRs) in daily clinical practice. Aims & Objectives To report the incidence of somnolence, nightmares, abnormal dreams, sleep paralysis, hypnotic hallucinations, suicidal ideation, and suicidal behavior in patients with insomnia disorder during treatment with LEM in daily clinical practice. Methods The enrollment period was from October 1, 2020 to September 30, 2021 with an observation period of 24 weeks. Informed consent was obtained from all subjects participating in the survey. Survey items included patient characteristics (eg, age, prior medication), incidence of AEs, overall improvement, and ADRs. The incidence rates of AEs and percentage of subjects demonstrating global improvement were calculated. Results The survey was conducted at 170 sites in 539 subjects. Among the 510 subjects included in the safety analysis, there were 210 males and 300 females; the mean age was 53.7 years and the proportion of subjects aged at least 65 years was 32.9%. The incidence of ADRs was somnolence 7.65% (39/510), nightmares 1.76% (9/510), abnormal dreams 0.59% (3/510), and sleep paralysis 0.20% (1/510). ADR incidence in this survey was similar to that reported in phase 3 studies. There were no ADRs related to hypnotic hallucinations, suicidal ideation, or suicidal behavior. The rate of global improvement in symptoms was 80.83% (371/459), excluding cases in which the evaluation time of global improvement was outside the acceptable range, the evaluation date was unknown, or a determination of improvement could not be made. Discussion & Conclusion The safety profile found in this analysis was comparable to that described in the LEM prescribing information, and the efficacy profile supports the clinical utility of LEM in the treatment of insomnia disorder. Support Eisai Co., Ltd.