Sosei Group Corporation announced that Idorsia Pharmaceuticals Japan Ltd. has submitted a New Drug Application ("NDA") to the Japanese Pharmaceuticals and Medical Devices Agency ("PMDA") for the approval of daridorexant (ACT-541468), a dual orexin receptor antagonist which has been co-developed with Mochida Pharmaceutical Co. Ltd. ("Mochida"), for the treatment of adult patients with insomnia. The NDA is supported by positive results of a randomized, double-blind, placebo-controlled Phase 3 study in Japan to investigate the efficacy and safety of Daridorexant.

The study met both primary and secondary efficacy endpoints. Daridorexant significantly improved subjective Total Sleep Time ("sTST"), a primary endpoint defined as the change from baseline compared to placebo at 28 days (p<0.001 for 50 mg, p=0.042 for 25 mg). Daridorexant also significantly improved sleep onset as measured by a decrease in subjective Latency for Sleep Onset ("sLSO"), a primary endpoint defined as The change from baseline compared to placebo At 28 days (p<0.,001 for 50 mg, p<0.006 for 25 mg).

The rate of adverse events was comparable between placebo and daridorexant at both treatment doses. About the Orexin system. Wake and sleep signaling is regulated by intricate neural circuitry in the brain.

One key component of this process is the orexin system, which helps promote wakefulness. There are two forms of orexin neuropeptides - small protein-like molecules used by nerve cells (neurons) to communicate with each other in the brain - orexin A and orexin B. Orexin promotes wakefulness through its receptors OX1R and OX2R. Together, these neuropeptides and receptors make up the orexin system.

The orexin system stimulates targeted neurons in the wake system - leading to the release of several chemicals (serotonin, histamine, acetylcholine, norepinephrine) - to promote wakefulness. Under normal circumstances, orexin levels rise throughout the day as wakefulness is promoted and then fall at night. Overactivity of the wake system is an important driver of insomnia.

The Japanese Phase 3 study was a randomized, double-blind., placebo-controlled, parallel-group, multicenter study to investigate the efficacy and safety the efficacy and safety of daridorexants in patients with insomnia disorder. The primary objective of the study was to demonstrate the efficacy of 50 mg of daridorexANT once daily at bedtime versus placebo for 4 weeks in patients with insomnia disorder. the efficacy of daridorexent was measured by patient reported total sleep time ("sTST") and latency to sleep onset ("sLSO").

The primary efficacy endpoint was change from baseline to Week 4 in sTST and change from baseline to Week 4 In sLSO with 50 mg daridorexant versus placebo. The secondary efficacy endpoint was change from baseline To Week 4 in sTST. and change from baseline to Week4 in sLSO with 25 mg daridorexants versus placebo.

The study also evaluated the dose effect of 50 or 25 mg of daridoreXant versus placebo using other patient reported sleep measures. MEDiSTRAVA Consulting (for International Media) Mark Swallow, Frazer Hall, Erica Hollingsworth.