In its full-year and fourth-quarter business highlights, Jazz Pharmaceuticals pointed to continued adoption of Xywav, approved to treat cataplexy and/or excessive daytime sleepiness in narcolepsy and idiopathic hypersomnia, with approximately 12,300 active patients exiting the fourth quarter, up from approximately 12,050 exiting the third quarter.

There were approximately 9,525 narcolepsy patients taking Xywav and approximately 2,775 idiopathic hypersomnia patients taking Xywav exiting 4Q23.

Xywav’s net product sales were up 33% over last year to $1.27 billion. Total sleep revenue, which includes Xywav, branded Xyrem, and high-sodium authorized generic royalty revenues, for the year exceeded $1.9 billion.

“As the only low-sodium oxybate and the only therapy approved to treat [idiopathic hypersomnia], expect Xywav to remain the oxybate of choice,” reads a release from the company.  

Highlights for the quarter included results from the real-world TENOR study being published in Sleep Medicine. The study found the most common reason cited for switching to Xywav was long-term health benefits due to the lower sodium content of Xywav.

Additionally, a review of scientific evidence was published in Neurology and Therapy showing oxybate regimens impart substantial and highly similar medical benefit on subjective and objective measures of sleep and daytime function regardless of dosing.

Additional Financial Highlights

Xyrem (sodium oxybate) oral solution:

  • Xyrem net product sales decreased 44% to $569.7 million in 2023 and decreased 57% to $106.7 million in 4Q23 compared to the same periods in 2022.

High-Sodium Oxybate Authorized Generic Royalties:

  • Royalties from high-sodium oxybate authorized generics were $75.9 million in 2023 and $39.4 million in 4Q23.
  • The company expects high-sodium oxybate authorized generic royalty revenue to exceed $200 million in 2024, which reflects an increase in the fixed-rate royalty structures of the authorized generic agreements in 2024.