Xywav for Idiopathic Hypersomnia Earns Orphan Drug Exclusivity

Orphan Drug designation is typically granted to drugs or biologics intended to treat, prevent, or diagnose rare diseases; in the United States, these are conditions affecting under 200,000 Americans. Drug developers also earn benefits from this designation. For example, Orphan Drug designation comes alongside fee waivers, tax credits, increased regulatory assistance, and 7 years market exclusivity upon approval. According to Nasdaq, JZP 258 (also known as Xywav), a therapy for patients with idiopathic hypersomnia, recently scored its Orphan Drug exclusivity following its earlier approval.


Drugs.com describes Xywav as:

a fixed mixture of 4 oxybate salts, namely: calcium oxybate, magnesium oxybate, potassium oxybate, and sodium oxybate (gamma-hydroxybutyrate).

Outside of idiopathic hypersomnia, Xywav may also be used for the treatment of narcolepsy. Xywav was developed by biopharmaceutical company Jazz Pharmaceuticals plc (“Jazz”). One of the benefits of Xywav is that it can be tailored for more precise and specific patient care. For example, the therapy offers multiple dosing options. Ultimately, this allows doctors and patients to determine the best line of care for themselves.

Interestingly, this is not the first Orphan Drug exclusivity granted to Xywav. In June of 2021, Xywav also received exclusivity for the treatment of cataplexy in those with narcolepsy aged 7+.

Idiopathic Hypersomnia

Doctors are not sure what exactly causes idiopathic hypersomnia, a chronic neurological sleep disorder. In fact, the condition is aptly named: “idiopathic” for without a known cause, and “hypersomnia” for excessive daytime sleepiness. This excessive sleepiness can interrupt day-to-day life, causing difficulty with staying awake and being alert. Additionally, people may struggle with tasks like driving or working, or may struggle to wake up from naps. Some medical professionals believe that abnormal hypersensitivity to sedation chemicals in the brain, or noradrenergic neuron destruction, could prompt idiopathic hypersomnia. However, this is still not known.

Typically, symptoms of idiopathic hypersomnia appear during adolescence or young adulthood. This condition can be variable. While some patients may experience relatively stable symptoms, others may experience more intense symptomatic fluctuations. Symptoms associated with this condition include:

  • Non-refreshing daytime napping
  • Chronic and excessive daytime sleepiness
  • Long periods of sleep (9-11 hours+) which do not result in feeling refreshed after waking
  • Sleep drunkenness (difficulty waking up; an urgent desire to go back to sleep)
  • Restlessness and irritability
  • Anxiety
  • Appetite loss
  • Mental fogginess and difficulty concentrating
  • Headache
  • Excessive sweating

Learn more about idiopathic hypersomnia.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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