Analyses Show High Effect Sizes and Low Numbers Needed to Treat With Pitolisant for Narcolepsy

In a post hoc analysis, pitolisant (Wakix; Harmony Biosciences, Plymouth Meeting, PA) reduced excessive daytime sleepiness (EDS) and cataplexy in adults with narcolepsy and severe symptom burden. The effects of pitolisant were assessed with the Cohen’s d test, a measure of effect size, and number needed to treat (NNT), which shows how many people need to be treated for the effect to be achieved in 1 individual. 

These analyses were done using data from 3 groups of patients including those with high daytime sleepiness (≥16 on Epworth Sleepiness Scale [ESS]), short sleep latency (≤8 minutes on the Maintenance of Wakefulness Test [MWT], and frequent cataplexy (≥15 attacks/week).
Among those with high daytime sleepiness (n=60), the NNT for at least a 3- point decrease or final score under 10 on ESS was 3. 

For those with frequent cataplexy (n-20), the NNT for a 50% reduction in weekly attacks was 2. For the Clinical Global Impression of Change (CGI-C), the NNTs for much or very much improved for those with high daytime sleepiness, short sleep latency, and frequent cataplexy were 5, 4, and 3, respectively. 

For pitolisant vs placebo, the Cohen’s d effect sizes were 0.80 for high daytime sleepiness, 0.31 for short sleep latency, and 1.31 for weekly cataplexy attacks. 
 
These data were presented at the annual meeting of the American Professional Sleep Societies, SLEEP 2022, held June 4-8 in Charlotte, NC.