0146 Efficacy and Safety of Single Dose of TS-142, a Novel and Potent Dual Orexin Receptor Antagonist, in Insomnia Patients

Abstract

Introduction TS-142 is a novel dual orexin receptor antagonist (DORA) developed for the treatment of insomnia. Here we report its pharmacokinetic profile in the healthy subjects and its efficacy and safety in patients with insomnia. Methods A phase1 study was conducted to clarify pharmacokinetic profile, in which various doses of TS-142 (1–30 mg) were orally administered once to thirty two healthy subjects. Subsequently, a phase 2a study utilizing polysomnography (PSG) was carried out in patients with primary insomnia, in which 5, 10, or 30 mg of TS-142, or placebo was randomly administered in a double-blind manner. Karolinska Sleepiness Scale (KSS) and Digit Symbol Substitution Test (DSST) were also examined in the morning after PSG. Results Following single administration of TS-142, plasma concentration of unchanged compound reached maximum within 2.50 h (median), and then eliminated rapidly, giving mean elimination half-life between 1.32 and 3.25 h. Twenty-three patients with insomnia completed the Phase2a study. Both latency to persistent sleep (LPS) and wake after sleep onset (WASO) were significantly improved with TS-142 at all doses, in comparison with placebo (-42, -42 and -45 for LPS [min] and -28, -35 and -55 for WASO [min] in 5, 10, 30 mg, respectively). KSS and DSST administered in the morning indicated no serious hangover effects. No serious adverse events were observed in these trials. Conclusion The phase 1 trial showed favorable pharmacokinetic profiles. The phase 2a trial demonstrated that TS-142 was efficacious in objective sleep onset and maintenance with minimal next-day residual effects. TS-142 was generally well tolerated in both studies. Support Taisho Pharmaceutical. Co., Ltd.