Neurim Pharmaceuticals has announced positive results from a phase II clinical study evaluating the efficacy and safety of Piromelatine (Neu-P11), a novel investigational multimodal sleep medicine developed for the treatment of patients with primary and co-morbid insomnia.

The new results are from a recent double-blind, randomized, placebo controlled, parallel group, non-confirmatory, sleep-laboratory study. The study evaluated piromelatine compared to placebo in 120 adult primary insomnia patients, ages 18 years and older. 

Piromelatine 20/50mg treatment for 4 weeks resulted in statistically significant and clinically meaningful improvements relative to placebo in key polysomnographic (PSG) parameters including Wake After Sleep Onset (WASO) (p=0.02 for both doses) and in particular WASO for the first 6 hours of sleep (WASO-6h) (p=0.0008 and p=0.04 for the 50 mg and 20 mg groups, respectively).

Piromelatine 50 mg also improved Sleep Efficiency (SEF) (p=0.02), Total Sleep Time (TST) (p=0.02), Total Time Awake (TTA) (p=0.01) and time in NREM sleep (p=0.028) indicating beneficial effects on sleep maintenance. Subjective improvements relative to placebo in quality of sleep and total sleep time measured by the Pittsburg Sleep Quality Questionnaire (PSQI) were also observed, confirming the PSG findings.

Piromelatine enhanced NREM sleep EEG delta power and significantly reduced beta power (p<0.05). The decrease in EEG beta activity, a marker of cortical arousal, is a physiological surrogate marker of the efficacy of Piromelatine in sleep maintenance.

Piromelatine was generally safe and well tolerated, had no detrimental effects on next-day psychomotor performance (as assessed by the Digit Symbol Substitution Test (DSST)) for any dose group and no deleterious effects on sleep structure and architecture.

 "Piromelatine demonstrates a good potential for the treatment of primary insomnia characterized by sleep maintenance disturbances as well as insomnia with psychiatric or medical co-morbidities" said Prof. Nava Zisapel, CSO of Neurim.

Results will be presented at the Sleep 2013 meeting in Baltimore.