Previously approved for the treatment of narcolepsy, pitolisant (marketed under the brand name Wakix) may soon be leveraged for another rare condition: idiopathic hypersomnia (IH). Pitolisant is a histamine 3 receptor antagonist/inverse agonist; it works by controlling levels of natural substances in the brain that correlate to sleepiness and wakefulness. According to a news release from pharmaceutical company Harmony Biosciences Holdings, Inc. (“Harmony”), the FDA recently granted Orphan Drug designation to pitolisant for IH.
Orphan Drug designation was started after the inception of the Orphan Drug Act, which aimed to increase drug development and review within the rare disease space. Now, this status is granted to therapies intending to treat, prevent, or diagnose conditions affecting fewer than 200,000 people across the United States. It comes with benefits such as increased FDA communication, fee waivers and tax credits, and even a 7-year period of market exclusivity if the drug is approved for this indication.
The Orphan Drug status was granted to pitolisant for idiopathic hypersomnia as Harmony has been evaluating the drug in clinical studies. Currently, Harmony is running the Phase 3 INTUNE clinical trial; more data on the study should be available later this year.
What is Idiopathic Hypersomnia (IH)?
Much like narcolepsy and cataplexy, idiopathic hypersomnia is considered a rare sleep disorder. However, while the cause of narcolepsy is known, doctors aren’t sure what causes IH; that’s why it is idiopathic (of an unknown cause). IH affects an estimated 80,000 people nationwide. However, many researchers believe that at least half of these individuals remain undiagnosed. While IH can affect people of all ages, symptoms often appear in teenage or young adult years. IH may also worsen in females around the time of menstruation.
One of the key features of idiopathic hypersomnia is excessive daytime sleepiness (EDS). This extreme sleepiness, which can be debilitating and impair quality-of-life, is not relieved by napping, resting, or even long periods of sleep. Other symptoms of idiopathic hypersomnia include appetite loss, anxiety or irritability, low energy, impaired cognitive skills, cold hands and feet, headaches, an immediate need for sleep, restlessness, or “sleep drunkenness,” which encompasses feelings of dizziness, grogginess, and disorientation.
Treatments are designed to relieve symptoms.
