Efficacy and safety of lemborexant in adults with insomnia: comparing Japanese and non-Japanese subgroups from the global, phase 3, randomized, double-blind, placebo-controlled SUNRISE 2 study.

Whether there are racial differences in the efficacy/safety of hypnotics has not been sufficiently investigated. We aimed to evaluate the efficacy/safety of lemborexant 5 mg (LEM5) and 10 mg (LEM10) versus placebo once daily in a subset of Japanese patients with insomnia and to compare the results with those of non-Japanese patients.
This subanalysis reports the results of the first 6 months (Period 1, placebo-controlled) of SUNRISE 2, a 12-month, global, randomized double-blind phase 3 study. Changes in patient-reported subjective sleep onset latency (sSOL), subjective sleep efficiency (sSE), and subjective wake after sleep onset (sWASO) with LEM5 or LEM10 versus placebo were evaluated. Treatment-emergent adverse events (TEAEs) were evaluated for safety.
In total, 949 patients were randomized (Japanese, n=161; non-Japanese, n=788). Groups were balanced at baseline except for male/female ratio (p=0.0002) and body mass index (p<0.0001) in the Japanese versus non-Japanese subgroups. Overall, the efficacy and safety of LEM was similar between subgroups. In the Japanese subgroup, sSOL change from baseline (CFB) was significant after 7 nights and 6 months with LEM10 versus placebo, sSE CFB was significant after 7 nights with LEM10 versus placebo, and sWASO CFB was significant at 6 months with LEM5 versus placebo. Incidence and severity of TEAEs were consistent between both subgroups.
LEM5/10 improved sleep onset and sleep maintenance over 6 months and was well-tolerated both in the Japanese and non-Japanese patients. Safety profiles of LEM5/10 were consistent between the subgroups.
Registry: ClinicalTrials.gov; Identifier: NCT02952820 and Registry: ClinicalTrialsRegister.eu; Identifier: 2015-001463-39.