- Jazz Pharmaceuticals said its experimental narcolepsy treatment was significantly more effective than placebo in a Phase 3 study measuring cataplexy attacks and changes in patients' scores on a sleepiness scale.
- The safety of the medicine, called JZP-258, is similar to that of the company's blockbuster narcolepsy product Xyrem, Jazz said in a Tuesday statement. The company noted that two serious adverse events were attributed to JZP-258 during the study, but it isn't disclosing details ahead of a full presentation of the results at an upcoming medical meeting.
- The biopharma plans to use the results, as well as those of an ongoing open-label study, to seek Food and Drug Administration approval of JZP-258.
Jazz is looking to the new therapy as the prospect of generic competition looms for Xyrem (sodium oxybate). Xyrem brought in $1.4 billion last year, accounting for almost three-quarters of the company's product sales.
There's plenty of time for Jazz to launch JZP-258 before the first authorized generic of Xyrem hits the market in 2023, Cowen & Co. analyst Ken Cacciatore wrote in a note to investors. And the therapy has the potential to win over Xyrem patients, potentially preventing a hit to Jazz revenue by the time Xyrem faces full generic competition at the beginning of 2026, he said.
JZP-258's advantage over Xyrem stems in part from its 92% lower sodium formulation. Too much sodium has been linked to higher risk of heart disease and other chronic disorders.
"Patients with narcolepsy may require lifelong medication, and there is a need for a new, low-sodium oxybate formulation," said Michael Thorpy, director of the Sleep-Wake Disorders Center at the Montefiore Health System in a statement from Jazz.
Cacciatore expects regulators and insurers will likely see the benefits of a lower sodium alternative, given the health risks. He wrote that it's possible a "full franchise conversion" to the new medicine will occur and hold into the 2030s.
Jazz said the most common adverse effects in its study were headache, nausea, dizziness, cataplexy, nasopharyngitis, decreased appetite, influenza, diarrhea and vomiting — effects that "essentially mirror" Xyrem's label, according to Cacciatore.
Earlier this month, Jazz secured a U.S. approval for another sleep drug, Sunosi (solriamfetol), which is cleared for treatment of excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea.