Abstract
Introduction
Pitolisant, a selective histamine H3 receptor antagonist/inverse agonist, increases histamine release in the brain. The efficacy of pitolisant in adults with narcolepsy was demonstrated in randomized, placebo-controlled trials. This study evaluated long-term use of pitolisant in clinical practice.
Methods
This prospective, open-label, 2-year, observational study was conducted at a major narcolepsy center in Germany and enrolled adults with a diagnosis of narcolepsy who had no prior treatment with pitolisant. Assessments included excessive daytime sleepiness (Epworth Sleepiness Scale [ESS]), weekly rate of cataplexy (WRC), and health-related quality of life (Short-Form Veterans RAND [VR-36]).
Results
The study enrolled 147 patients: mean age, 29.9 years; 57.1% female, 65.3% with cataplexy, and 66.7% with disrupted nighttime sleep. In patients who were tested, CSF hypocretin-1 was <110 pg/mL in 70.8% (51/72), and 79.4 % (77/97) were HLA-DQB1*0602 positive. The pitolisant dose was 35.6 mg/d in 38.1% of patients at Month 3, and 73.5% at Month 24. Most patients received concomitant narcolepsy medications (63.3% at baseline; 79.6% at month 24). Mean ESS score decreased from 16.2 at baseline to 12.4 at Month 12 and 12.6 at Month 24. Mean WRC was reduced by 31% at Month 24. Significant improvement in quality of life was noted at Months 12 and 24 on VR-36 subscales that assess general health perception, vitality, and social function. In all, 38 patients (25.8%) discontinued from the study before Month 24: 15.0% for lack of efficacy and 10.8% due to adverse events. The most common adverse events were disrupted nighttime sleep (29.3% of patients), headache (15.5%), and nausea (12.2%).
Conclusion
These real-world data show that long-term treatment with pitolisant (usually with 35.6 mg/d) was efficacious for reducing EDS and cataplexy and improving quality of life in patients with narcolepsy. Treatment was generally well tolerated.
Support
Writing support funded by Harmony Biosciences, LLC.