0453 Lemborexant Exposure Is Independent of Race

Abstract

Abstract Introduction Some hypnotic treatments for insomnia require dosing consideration due to exposure differences based on patient characteristics. Lemborexant (LEM) is a dual orexin receptor antagonist approved in multiple countries for the treatment of adult insomnia. LEM is not associated with exposure differences based on sex, age, or BMI that impact dosing. The potential impact of race on exposure was determined in two stand-alone pharmacokinetic (PK) studies and by modeling data from studies comprising the LEM clinical development program, which included healthy subjects and insomnia patients. Methods Study 003 (NCT02039089) was a single-center, multiple-dose, randomized, double-blind, placebo-controlled, parallel-group study in healthy Japanese and White subjects. Study 014 (NCT04555733) was a phase 1, single center, open-label, single and multiple oral dose study in healthy Chinese subjects. Additionally, effect of race on LEM exposure was independently examined as part of a population PK analysis incorporating LEM data from 9 Phase 1 studies (n=407), and Studies 201 (NCT01995838; n=235), 303 (NCT02952820; n=726) and 304 (NCT02783729; n=524) (Lalovic et al., 2020). Plasma concentrations of LEM were quantified from plasma by validated liquid chromatography with tandem mass spectrometry. Adverse events (AE) were recorded. Results Exposure of LEM increased in an approximately dose-proportional manner across the dose range (2.5 mg to 25 mg) in studies 003 and 014. There were no significant exposure differences between Japanese and White subjects following single LEM10 administration on Day 1 in Study 003 (maximum concentration [Cmax] mean[SD], ng/mL: Japanese, 46.5[25.8]; White, 47.3[28.1]; area under the curve from time zero to 24h [AUC0-24] mean[SD], ng·h/mL: Japanese, 231[40.2]; White, 208[83.4]) or when comparing PK data from Chinese subjects in Study 014 following single dose administration on Day 1 (Cmax mean[SD], ng/mL: LEM5, 29.8[12.8]; LEM10, 56.2[16.9]; LEM25, 116[46.8]; AUC0-24 mean[SD], ng·h/mL: LEM5, 106[29.9]; LEM10, 205[35.6]; LEM25, 549[116]) to Japanese and White subjects in Study 003. These results are supported by the cross-study, population PK model-based analysis, indicating no significant clinical or statistical differences in LEM PK attributable to the intrinsic factor race. Conclusion LEM exposure is not significantly affected by race. Therefore, dosing of LEM can be consistent across patient populations from different racial groups. Support (If Any) Eisai Inc.