Harmony Biosciences’ pitolisant shows positive Phase 2 results in DM1

Harmony Biosciences announced positive topline results from its Phase 2 signal detection study evaluating the safety and efficacy of pitolisant in adult patients with myotonic dystrophy type 1, or DM1. A clinically meaningful improvement was demonstrated on the primary efficacy endpoint, the change from baseline to the end of the double-blind period for excessive daytime sleepiness. A clinically meaningful improvement was also demonstrated for fatigue, a secondary efficacy endpoint measured by the Fatigue Severity Scale. EDS and fatigue occur in up to 80-90% of patients with DM1 and impact daily functioning as much as muscular symptoms. A clear and consistent dose-response was demonstrated with the higher dose pitolisant group showing a greater response than the lower dose group across the study endpoints. Safety and tolerability profile in adult patients with DM1 was consistent with the established safety profile of pitolisant with no new safety signals detected and no serious adverse events reported. This study was not powered to demonstrate statistical significance. Pitolisant is not approved for use in patients with DM1 and is currently being evaluated as an investigational agent in this patient population.