Efficacy of long-term treatment with daridorexant in patients with insomnia disorder on sleep and daytime functioning: a post-hoc analysis

Abstract: Daridorexant improved night and daytime symptoms of insomnia disorder in two parallel, phase 3, 12-week studies with maintained improvements over a 40-week extension study. The largest effect in the 12-week studies occurred with daridorexant 50 mg. A post-hoc analysis of the extension study evaluated long-term efficacy of daridorexant 50 mg, compared with placebo and daridorexant 25 mg. This post-hoc analysis includes 392 patients (≥18 years) with insomnia disorder randomised to daridorexant 50 mg, 25 mg or placebo and completed 12-weeks of treatment (NCT03545191) and subsequently entered the 40-week extension study (NCT03679884), totaling 1 year of treatment. In the extension study, patients initially randomized to daridorexant resumed their medication dose whereas those receiving placebo were re-randomized to receive daridorexant 25 mg or placebo. Exploratory endpoints included subjective total sleep time (sTST) and daytime functioning, assessed by Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ) total and domain scores (sleepiness, alert/cognition, and mood); lower scores indicating improved daytime functioning. For patients in the extension study, mean increases in sTST from baseline to 12 months was largest with daridorexant 50 mg versus 25 mg and placebo. For IDSIQ total and domain scores, reductions were also consistently larger with 50 mg throughout the 12-month treatment period, compared with daridorexant 25 mg and placebo. IDSIQ sleepiness, alert/cognition, and mood domain scores also favored daridorexant 50 mg. This post-hoc analysis provides additional evidence for the long-term maintenance over 12 months of the favourable treatment effect of daridorexant 50 mg for patients with insomnia disorder.Short Description: Initial 12-week studies showed that the largest effect on improved night-time and daytime symptoms was observed with daridorexant 50 mg. This post-hoc analysis provides additional evidence of the favorable treatment effect with daridorexant 50 mg with long-term use over 12 months on both nighttime symptoms and daytime functioning, based on an increase in sTST and improvement in IDSIQ scores, in patients with insomnia disorder.Name of Sponsoring Organization(s): Idorsia Pharmaceuticals Ltd