FDA Approves Avadel's Narcolepsy Drug Lumryz for Children

Children with narcolepsy cannot choose when to wake or sleep. Image credit: Shutterstock/Roman Samborskyi.

Paediatric patients suffering from narcolepsy now have access to a new treatment option, Lumryz (sodium oxybate), thanks to an approval by the US Food and Drug Administration (FDA) of a supplemental new drug application. The expanded approval, announced on 17 October, permits the use of Lumryz for treating sudden muscle weakness known as cataplexy, as well as excessive daytime sleepiness (EDS) in individuals aged seven and older with narcolepsy.

Previously approved for use in adults in the United States in May last year, Lumryz has also been granted seven years of orphan drug exclusivity. This status ensures that the FDA will not approve any other marketing application for a similar competing product until October 2031.

Narcolepsy is a chronic neurological disorder that affects the brain's ability to control sleep and wake cycles, leading to an inability to choose when to wake or sleep. Common symptoms among those with narcolepsy include EDS and cataplexy, with the latter affecting 70% of patients. Although narcolepsy is not typically associated with serious health issues, it can considerably impact everyday life.

Lumryz is believed to function by interacting with gamma-aminobutyric acid B receptors in noradrenergic and dopaminergic neurons, which increases the time a person spends in deeper sleep stages. However, the drug carries a boxed warning due to its classification as a central nervous system depressant and its potential for abuse and misuse.

The broadening of Lumryz's use has heightened the competitive landscape against Jazz Pharmaceuticals' similar treatments, Xyrem (sodium oxybate) and the more recent Xywav, which is a combination of calcium, magnesium, potassium, and sodium oxybates. Unlike Lumryz, Jazz’s medications require patients to wake during the night to take a second dose. The FDA found this dosing regimen less favorable when it granted the exclusive market period to Lumryz, stating it was superior to Jazz’s drugs based on the once-nightly dosing schedule, according to Avadel.

Greg Divis, CEO of Avadel, emphasized the importance of this approval for younger narcolepsy patients and their caregivers, who often face significant challenges due to the need to wake up in the middle of the night for treatment regimens. Divis noted, “With this label expansion, paediatric patients seven years and older living with narcolepsy now have the same option that adult patients with narcolepsy have – to choose a once-nightly treatment option that does not disrupt sleep for a middle of the night dose."

Xyrem, a leading product in this category, achieved peak sales of $1.7 billion in 2020. However, its sales declined following the approval of Xywav, which offers more flexible dosing. Xywav surpassed $1 billion in revenue last year and is projected to generate over $1.8 billion by 2030, according to GlobalData’s Pharma Intelligence Centre. In comparison, Lumryz is forecasted to bring in $639 million in the same year.

Jazz Pharmaceuticals has taken legal action against Avadel in recent years to prevent Lumryz’s market entry, including initiating multidistrict patent infringement lawsuits and suing the FDA. In March this year, a jury from the United States District Court for the District of Delaware ruled in favor of Avadel on one patent issue while siding against them on another. Avadel has announced its intention to appeal the decision and stated that the legal proceedings would not affect Lumryz's ongoing commercial launch.

Earlier this year, Jazz Pharmaceuticals also faced legal issues regarding misleading promotion of Xyrem, resulting in the company agreeing to pay $20 million in civil and criminal penalties over a five-year period.