Efficacy of pitolisant in patients with high burden of narcolepsy symptoms: pooled analysis of short-term, placebo-controlled studies

Study objective: To evaluate the efficacy of pitolisant, a histamine 3 (H₃)-receptor antagonist/inverse agonist, in adult patients with high burden of narcolepsy symptoms. Methods: Data were pooled from two randomized, placebo-controlled, 7- or 8-week studies of pitolisant (titrated to a potential maximum dose of 35.6 mg/day) in adults with narcolepsy. Analyses included three independent patient subgroups: Epworth Sleepiness Scale (ESS) baseline score ≥16, Maintenance of Wakefulness Test (MWT) sleep latency ≤8 min, and ≥15 cataplexy attacks per week. Results: The analysis populations included 118 patients for ESS (pitolisant, n = 60; placebo, n = 58), 105 for MWT (pitolisant, n = 59; placebo, n = 46), and 31 for cataplexy (pitolisant, n = 20; placebo, n = 11). On the ESS, least-squares mean change from baseline was significantly greater for pitolisant (−6.1) compared with placebo (−2.3; P < 0.001). Significantly more pitolisant-treated patients were classified as treatment responders: ESS score reduction ≥3, 69.0% in the pitolisant group versus 35.1% in the placebo group (P = 0.001); final ESS score ≤10, 36.2% versus 10.5%, respectively (P = 0.005). On the MWT, mean sleep latency increased from 3.5 min to 10.4 min with pitolisant and from 3.4 min to 6.8 min with placebo (P = 0.017). Least-squares mean change in the weekly rate of cataplexy was significantly greater for pitolisant (−14.5; baseline, 23.9; final, 9.4) compared with placebo (−0.1; baseline, 23.1; final, 23.0; P = 0.004). Headache was the most common adverse event with pitolisant. Conclusions: Pitolisant, at once-daily doses up to 35.6 mg, was efficacious for reducing excessive daytime sleepiness and cataplexy in patients with severe narcolepsy symptom burden.