Positive topline results were announced from the second pivotal phase 3 study evaluating daridorexant (Idorsia), an investigational dual orexin receptor antagonist, for the treatment of insomnia.

The multicenter, double-blind, placebo-controlled study evaluated the efficacy and safety of daridorexant in 924 adult patients (39.3% ≥65 years of age) with insomnia. Patients were randomized to receive either daridorexant 10mg, 25mg, or placebo once in the evening. The co-primary end points were the change from baseline to months 1 and 3 in sleep onset, as measured by a decrease in latency to persistent sleep, and sleep maintenance, as measured by a decrease in wake time after sleep onset. 

Findings showed that daridorexant 25mg significantly improved sleep maintenance at months 1 and 3 compared with placebo, as measured objectively in a sleep lab by polysomnography. Daridorexant 25mg also significantly improved subjective total sleep time (key secondary end point), as measured daily with a patient diary at home. 

Additionally, improvements in sleep onset and daytime functioning consistent with that seen in the first phase 3 trial were also observed with the 25mg dose, however, these end points did not reach statistical significance. While the 10mg dose of daridorexant was associated with improvements across all efficacy measures, these were not found to be statistically significant.

With regard to safety, the most common treatment-emergent adverse events observed in the study included nasopharyngitis, headache, somnolence and fatigue. Daridorexant was associated with a low frequency of excessive daytime sleepiness. Moreover, patients did not report next morning residual effects, rebound insomnia, or withdrawal symptoms upon discontinuation.  

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Detailed study results will be made available through scientific disclosure at upcoming congresses and in peer reviewed publications. The Company is planning to submit a New Drug Application to the Food and Drug Administration by the end of 2020.

For more information visit idorsia.com.