SLEEP 2019: Beneficial Effect of Pitolisant in Children with PWS Reinforces Role of SLEEP Medicine in the Rare Disease
June 19, 2019
Chion Foundation has partnered with TREND Community to track nine children with Prader-Willi Syndrome (PWS) who are being treated with pitolisant. Lara C. Pullen, PhD, President of Chion Foundation, based in Chicago, Illinois and colleagues presented their results in the poster session on June 9th at the SLEEP 2019 meeting held in San Antonio, Texas. The investigators reported that most of the children have now been taking pitolisant for years and continue to report a positive response.
The poster presented data on seven children. The authors note that two families discontinued pitolisant. One child, who was also taking methylphenidate, discontinued due to anxiety and behavioral issues. The other family experienced benefits from pitolisant but the cost of the drug was unsustainable. The families import pitolisant from Europe with approval at the Food and Drug Administration’s (FDA) discretion and pay approximately $20,000/year. Two additional families report dosing data to TREND, but do not track their child’s experiences with pitolisant. Their data were not included in the poster.
The families reported dosages that are higher than those currently being tested in Europe for pediatric patients with narcolepsy and dosages plateaued at different levels for different age groups: 22.5 mg (1.1 mg/kg) for children ages 2 – 6 years, 36 mg (0.7 mg/kg) for children ages 6 – 12 years, and 22.5 mg (0.3 mg/kg) for children ages 12 – 18 years. “I think it is important to keep in mind that these dosages may be artificially suppressed,” pointed out Dr. Pullen. “The patients are paying out-of-pocket for pitolisant and the cost is very high. Many families feel that they can’t afford to increase the dose even though they suspect that the child would benefit from a higher dose.”
Families continue to report that pitolisant was associated with improved mental clarity and processing speed. “We are presenting data from our weekly questionnaire,” said Dr. Pullen. “What you aren’t seeing here are the stories Chion Foundation receives daily about children earning a place on the honor roll at school, or able to more actively participate in conversations, or form more friendships with peers.”
While the patient-experience data do not include formal measures of cognition, family reports suggest that pitolisant improves cognition in children with PWS. “While each family has one or more tests that objectively document cognitive improvements, no single standardized test was run on all children,” explained Dr. Pullen. Pitolisant also appeared to improve quality of life as measured by anger and sadness, particularly in the children 6 - 12 years of age.
The investigators reported that, while the seven children in the case series were frequently sleepy during the day and all had global low tone, they did not present with typical adult symptoms of narcolepsy. The findings would thus suggest that there may be reason to treat children with PWS with pitolisant even in the absence of a formal diagnosis of narcolepsy. They also suggest that, consistent with recent data from mouse models of PWS, sleepiness or even impaired circadian rhythm may be drivers of many of the symptoms of PWS.