Novel Use of Sleep Drug Gives Children with Rare Disease New Life
Pitolisant, a novel drug for treating the rare disease narcolepsy, may also be able to relieve substantial aspects of the burden of another rare disease: Prader-Willi Syndrome (PWS). A clinical vignette, published today in the Journal of Pediatric Pharmacology and Therapeutics, describes three children with PWS who experienced improvements in cognitive disability, excessive daytime sleepiness, and poor-quality nighttime sleep in response to treatment with pitolisant.
The European Medicines Agency has approved pitolisant, a histamine 3 receptor inverse agonist, for the treatment of narcolepsy with or without cataplexy. Last year the United States Food and Drug Administration granted Breakthrough Therapy and Fast Track designations to pitolisant for the treatment of excessive daytime sleepiness and cataplexy in patients with narcolepsy.
While the children in this case series did not have a diagnosis of narcolepsy, they did demonstrate the daytime sleepiness that is commonly seen in children with PWS. The fact that pitolisant was able to improve daytime sleepiness in these children is not surprising. What is more interesting is that pitolisant might have improved their processing speed and mental clarity. Results from previous studies suggest that pitolisant may have a positive effect on cognition and the observations in the case series are consistent with this.
Pitolisant treatment had the additional benefit of normalizing the children’s relationship to food, a benefit that is noteworthy given that hyperphagia is common in this population.
The case series describes families self-report of their experience with pitolisant via a novel online data-gathering platform called TREND Community. The children were of different ages (10 – 15 years) and different developmental stages. They were dosed from 4.5 mg/day up to 31.5 mg/day). Parents reported their experience via subjective Likert scaling as well as open-ended journaling.
“The TREND platform makes it possible for us to document how patients and families experience the response to a new treatment,” explained author Maria Picone, Co-Founder of Chion Foundation and Co-Founder/CEO of TREND Community in Philadelphia, Pennsylvania. “For example, we found that children responded rapidly, within days, to treatment with pitolisant.”
Parents also reported that pitolisant was well-tolerated.
Two of the three children occasionally noted headaches that lasted for two days following initiation of pitolisant and with each dose increase. Parents of two of the three children noted that they were often anxious prior to the initiation of pitolisant. That anxiety decreased (but did not completely resolve) over time on pitolisant.
“We were very pleased to see that pitolisant was so well-tolerated by the children,” said lead investigator Lara C. Pullen, PhD, President and Co-Founder of Chion Foundation in Chicago, Illinois. “I think that this speaks to the fact that pitolisant is not a stimulant. Instead, it seems to normalize systems that are dysregulated in the bodies of individuals with PWS.”
While the paper describes only three children with PWS who are being treated with pitolisant, the authors note in their discussion that they are now following ten children with PWS who are having a similar positive response to treatment with this novel drug.
Lara C. Pullen, Maria Picone, Litjen Tan, Charles Johnston, and Holger Stark (2019) Cognitive Improvements in Children with Prader-Willi Syndrome Following Pitolisant Treatment—Patient Reports. The Journal of Pediatric Pharmacology and Therapeutics: March-April 2019, Vol. 24, No. 2, pp. 166-171.