Jazz Pharmaceuticals gets FDA OK for cataplexy drug as it prepares to replace old cash cow
Following an FDA approval just last month for its small cell lung cancer drug, Jazz Pharmaceuticals keeps on rolling.
The Irish pharma announced Wednesday that Xywav, treating cataplexy and excessive daytime sleepiness associated with narcolepsy in patients older than seven years, has been given the green light by US regulators. This is the third FDA approval granted to Jazz in the last 16 months and the second narcolepsy-related drug after Sunosi was OK’ed in March 2019.
Jazz plans to launch the new drug by the end of 2020 after Risk Evaluation and Mitigation Strategy implementation.
Cataplexy is the sudden loss of muscle tone normally triggered by strong emotions, and it is commonly experienced in those who suffer from narcolepsy. Jazz has made these disorders central to their portfolio. In addition to Sunosi, the pharma already has a blockbuster narcolepsy drug on the market in Xyrem, which accounted for $1.4 billion in 2018 sales or 70 percent of the company’s total revenue.
Although Xyrem has been a boon, concerns arose due to the drug’s high sodium content as a sodium oxybate. Xywav, which like Xyrem is an oxybate-based drug, contains 92 percent less sodium than its predecessor, and Jazz hopes the new treatment will replace Xyrem as the standard of care.
“Xywav is still an oxybate molecule, so it works in the same mechanism of action of sodium oxybate,” Richard Bogan, lead investigator of the Phase III trial, told Endpoints News. “We expect it to be as equally effective [as Xyrem] and that’s what the clinical trials demonstrated, that it was efficacious.”
Jazz notes that Xywav and Xyrem have the same oxybate concentration. But Xywav includes a mix of calcium, magnesium, potassium and sodium cations, Bogan said, and most patients were able to transition from one medicine to the other with minimal side effects.
“We were able to use what we call asymmetric dosing so we could adjust the first and the second dose, which is kind of a new methodology that’s now acceptable to the FDA that we had used clinically in the past,” Bogan said. “The important message is that those patients who were on Xyrem, we just converted them the next day to the same dose of Xywav, and then we have a period of time where we could tweak the dose if we wanted to.”
Again like Xyrem, Xywav also comes with a black box warning as a central nervous system depressant and for potential abuse and misuse. As such, it’s only available through a restricted REMS program. Given that the FDA had already accumulated lots of applicable data from previous Xyrem testing, and due to the similarities of the drugs, Jazz and Bogan are confident in Xywav’s safety and efficacy profiles.
The Xywav compound, dubbed JZP-258, is also in the Phase III clinical trial stage for the treatment of idiopathic hypersomnia, or excessive sleepiness. This differs from narcolepsy in that patients with IH do not experience the sudden onset of REM sleep cycles more than once per sleep period.