Pitolisant Clinical Trial for Type 1 Myotonic Dystrophy Excessive Daytime Sleepiness

A phase 2 clinical trial (NCT04886518) for pitolisant (Wakix; Harmony Biosciences, Plymouth Meeting, PA) in adults with type 1 myotonic dystrophy (DM1) experiencing excessive daytime sleepiness (EDS) and other nonmuscular symptoms has been initiated. The trial will evaluate the effect of pitolisant compared with placebo on EDS using assessments of fatigue, specific measures of cognitive function via validated computer-based assessments, and overall disease.

"In addition to the primary symptoms of myotonia and muscle weakness in patients with type 1 myotonic dystrophy, the nonmuscular symptoms of excessive daytime sleepiness, fatigue, and cognitive dysfunction are very common in these patients and have a negative impact on daily functioning as much as, or more so, than the primary muscle symptoms of the disease," said Harmony’s chief medical officer, Jeffrey Dayno, MD "Pitolisant’s novel mechanism of action increases histamine transmission in the brain which provides the scientific rationale for its potential clinical utility for the common nonmuscular symptoms in patients with DM1. We listened to the needs of patients and caregivers in the myotonic dystrophy patient community and are pleased to have initiated this phase 2 clinical trial to assess the potential clinical benefit of pitolisant in patients with this rare neurological disease, for which there are currently no approved treatment options." 

This phase 2 clinical trial is a randomized double-blind placebo-controlled study enrolling participants from 18 years to 65 years of age with DM1. Approximately 135 participants will be randomly assigned into 3 groups: low-dose pitolisant, high-dose pitolisant, or placebo in a 1:1:1 treatment ratio titrated over 3 weeks. Titration will be followed by 8 weeks of stable dosing. Participants who complete the randomized, controlled phase of the trial will be eligible for the open-label extension phase to assess the long-term use of pitolisant in individuals with DM1.