Paediatric patients with narcolepsy will now have access to Avadel’s Lumryz (sodium oxybate) after the US Food and Drug Administration (FDA) approved a supplemental new drug application.
The expanded approval for the oral suspension is for the treatment of sudden muscle weakness, called cataplexy, or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy, as per a 17 October press release.
Lumryz, which was approved in adults in the US in May last year, was also granted seven years of orphan drug exclusivity. This means the FDA will not approve another marketing application for a competing product until October 2031.
Narcolepsy is a chronic neurological disorder that impacts the brain's ability to regulate sleep and wake cycles, meaning people cannot choose when to wake or sleep. EDS and cataplexy are common symptoms in those with the disorder, with the latter occurring in 70% of patients. Whilst narcolepsy itself does not cause serious health problems; it has a significant impact on day-to-day life.
It is thought Lumryz works by binding to gamma-aminobutyric acid B receptors in noradrenergic and dopaminergic neurons, increasing the time a person spends in deeper sleep. The treatment has a boxed warning as a central nervous system depressant, and for its potential for abuse and misuse.
The widened use of Lumryz intensifies the competition with Jazz Pharmaceutical’s rival compounds Xyrem (sodium oxybate) and blockbuster Xywav, a mixture of calcium, magnesium, potassium, and sodium oxybates. Unlike Lumryz, Jazz’s twice-nightly drugs require patients to wake up in the middle of sleep to take the second dose. The FDA highlighted this when granting the exclusive market period to Lumryz, ruling it was superior to Xyrem and Xywav due to the dosing regimen, according to Avadel.
Avadel’s CEO Greg Divis said the approval is important for younger narcolepsy patients and their caregivers who “face significant challenges associated with waking up in the middle of the night to complete treatment regimens”.
“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,” he added.
Xyrem saw peak sales in 2020, bringing in annual revenue of $1.7bn. Xyrem sales decreased after the approval of Xywav, with the latter having more flexible dosing. Xywav passed the $1bn revenue mark last year and is forecast to generate more than $1.8bn by 2030, according to GlobalData’s Pharma Intelligence Centre. Lumryz is forecast to make $639m in the same year.
GlobalData is the parent company of Pharmaceutical Technology.
Jazz Pharmaceuticals has initiated multidistrict patent infringement lawsuits against Avadel over the past few years to block Lumryz’s entry to market, in addition to suing the FDA itself. A jury from the United States District Court for the District of Delaware gave its verdict in March this year, siding with Avadel for one patent whilst ruling against the company in relation to another. Avadel said it would appeal the decision and added legal proceedings would not impact the ongoing commercial launch of Lumryz, as per a statement at the time.
Jazz was in court another time this year relating to a separate matter of misleading promotion relating to Xyrem. The company agreed to pay $20m in civil and criminal penalties over a period of five years.
