Biopharmaceutical company Harmony Biosciences LLC said on Tuesday that it has successfully filed its New Drug Application (NDA) for pitolisant for narcolepsy with the US Food and Drug Administration (FDA) under Priority Review.

Narcolepsy is a rare, chronic, debilitating neurologic disorder of sleep-wake state instability that impacts up to 200,000 Americans and is primarily characterised by EDS, and other manifestations of REM sleep dysregulation, which intrude into wakefulness. Cataplexy is one of several symptoms of narcolepsy.

The company added that the investigational product Pitolisant is a first-in-class molecule with a novel mechanism of action; it is a potent and highly selective histamine 3 (H3) receptor antagonist/inverse agonist for the potential treatment of excessive daytime sleepiness (EDS) and/or cataplexy in adult patients with narcolepsy.

If approved by the US FDA, pitolisant would provide a significant improvement in the safety or effectiveness of the treatment of EDS and/or cataplexy in adult patients with narcolepsy when compared to existing treatments. The company's goal is to obtain the US FDA approval to market pitolisant in the nation in 2019.

This NDA submission is based on results from the company's clinical development programme in narcolepsy, which included over 300 patients, some of whom were treated for up to five years. It included safety data in over 1500 patients across multiple patient populations.