Respiratory Safety of Lemborexant in Healthy Subjects: A Single-Dose, Randomized, Double-Blind, Placebo-Controlled, Crossover Study.

Background And Objective: Lemborexant is a dual orexin receptor antagonist recently approved in the USA, Japan, and Canada for the treatment of adults with insomnia. Because some pharmacotherapy for insomnia causes respiratory depression, this study assessed the effects of lemborexant treatment on respiratory safety parameters.

Methods: This single-dose, randomized, double-blind, placebo-controlled, three-period crossover study enrolled healthy adult and elderly subjects (n = 17). Subjects were randomized to one of three treatment sequences, each consisting of three treatment periods in which they received a single dose of placebo, lemborexant 10 mg, or lemborexant 25 mg. Each treatment period was separated by a washout period of at least 14 days. Assessments included pharmacodynamic respiratory parameters (peripheral capillary oxygen saturation (SpO) and apnea-hypopnea index (AHI)) and safety.

Results: There were no significant differences for either dose of lemborexant versus placebo in mean peripheral capillary oxygen saturation (SpO; least squares mean (LSM) difference (95% confidence interval (CI)): lemborexant 10 mg, -0.36 (-0.78 to 0.07); lemborexant 25 mg, - 0.29 (- 0.72 to 0.14)) or AHI (LSM difference (95% CI): lemborexant 10 mg, 0.52 (- 1.72 to 2.76); lemborexant 25 mg, - 1.16 (- 3.40 to 1.08)) during sleep. Additionally, significant differences were not observed for the percentage of total sleep during which SpO was < 85% (LSM difference (95% CI): lemborexant 10 mg, 0.004 (- 0.058 to 0.067); lemborexant 25 mg, 0.044 (- 0.018 to 0.107)) or < 80% (LSM difference (95% CI): lemborexant 10 mg, 0.001 (- 0.002 to 0.005); lemborexant 25 mg, 0.002 (-0.001 to 0.006)) for either lemborexant dose versus placebo. There was also no significant difference for lemborexant 10 mg versus placebo, for which SpO was < 90% during total sleep time (LSM difference (95% CI): 0.185 (- 0.034 to 0.405)).

Conclusion: Overall, lemborexant at recommended doses did not have a negative effect on mean SpO or AHI and was well tolerated in this cohort of healthy subjects.