 PLYMOUTH MEETING, Pa., June 29, 2021 PRNewswire -- Harmony Biosciences Holdings, Inc. Harmony Nasdaq: HRMY, a pharmaceutical company dedicated to developing and commercializing innovative therapies for patients living with rare neurological disorders who have unmet medical needs, today announced initiation of a Phase 2 clinical trial to evaluate the safety and efficacy of pitolisant for excessive daytime sleepiness EDS and other non-muscular symptoms in adult patients with type 1 myotonic dystrophy DM1. 