358 Daridorexant Improves Sleep in Patients with Mild/Moderate Obstructive Sleep Apnea

Abstract Introduction Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia. The effect of the highest phase-3 dose of 50 mg daridorexant on nighttime respiratory function was evaluated in patients with mild/moderate obstructive sleep apnea (OSA). This study showed that repeated doses of daridorexant had no clinically meaningful effect on the apnea-hypopnea index (AHI) or on peripheral oxygen saturation. In the same study, the effect on objective sleep parameters was also explored by polysomnography (PSG). Methods In this randomized, double-blind, placebo-controlled, two-period, crossover study, daridorexant or placebo was administered in each period once daily for 5 consecutive nights to 28 patients. Treatment difference (daridorexant – placebo) for total sleep time (TST), latency to persistent sleep (LPS), and wake after sleep onset (WASO) was analyzed for Night 5 using linear mixed-effects modeling. In addition, sleep was further explored based on sleep duration during each hour of PSG recording, duration of the different sleep phases (rapid eye movement [REM], non-REM [including N1 to N3 sleep stages]), as well as number and mean/longest duration of awakenings. Results Of 28 patients enrolled, 25 completed the study and were included in the analysis (n=15/10 with mild/moderate OSA; mean [standard deviation] AHI: 16.3 [8.2] events/h). One patient had mild insomnia symptoms at baseline. Compared to placebo, daridorexant prolonged mean TST by 38.8 min (90% confidence interval: 19.7–57.9), shortened mean LPS by 17.2 min (-35.5–1.02), and reduced mean WASO by 31.0 min (-47.3 to 14.7). Sleep architecture was maintained as no treatment differences in the duration of the evaluated sleep stages were observed when normalized to TST. Sleep duration was prolonged in the second part of the night. mean and longest duration of awakenings were decreased by a mean (90% CI) of 2.0 min (-3.1 to 0.9) and 16.3 min (-24.1 to -8.6), respectively, without treatment difference for the total number of awakenings. Conclusion Daridorexant improved objective sleep parameters in patients with mild to moderate OSA without modifying sleep architecture. Support (if any) Funded by Idorsia Pharmaceuticals Ltd.