Narcolepsy Treatment: Xywav Making Waves

Jazz Pharmaceuticals has historically relied on its top-selling medication Xyrem, a narcolepsy medication, accounting for almost 75% of the company’s sales in 2020. However, the threat of generic formulations, slated to enter the market in 2023, poses a significant risk to Jazz. In anticipation of this last November, Jazz began commercializing a lower-sodium formulation of Xyrem called Xywav.

About the Data

Earnest Healthcare provides visibility into $1 trillion of de-identified U.S. healthcare claims. This dataset includes insight into drug prescriptions, medical procedures, adjudicated pricing, and diagnosis group, with the ability to cohort by particular geographies (region, state, etc.), channel (telehealth, office, etc.), facility type (in/outpatient, ASC, etc.), insurance type (commercial, Medicare, etc.) and more. Learn more.

Key Takeaways

Xywav Ramping

Following 1Q21, the first complete commercialized quarter of Xywav, the new drug accounted for 18% of company reported net narcolepsy sales, in line with Earnest claims data of 21%. Claims for the full quarter of 2Q21, as well as the current quarter in progress (3Q21), suggests continued growth in Xywav sales as a share of Jazz’s total narcolepsy drug sales.

Pace of Switching

How successful are Jazz’s efforts to switch patients onto the new formulation?

While it’s phase III trial demonstrated that patients that switched from Xyrem to Xywav continued to experience low rates of cataplexy attacks and excessive daytime drowsiness (compared to placebo), the company’s ability to commercially switch patients over is key to its success.

We identified Xywav patients that were both recently and/or previously on Xyrem, and looked at their claims performance accordingly. To date, 24% of patients recently on Xyrem have since switched onto Xywav, indicating strong momentum in Jazz’s switching efforts with room for continued growth. 

Of total patients currently on Xywav, 68% were recent Xyrem users (defined as those using Xyrem in the weeks leading up to and/or since the launch of Xywav in Oct/Nov ‘20), 13% were older Xyrem users, and the remaining 19% were new patients to Jazz’s oxybate franchise.

Recently, the company filed an application with the FDA to expand Xywav into a new indication, seeking the drug’s approval for idiopathic hypersomnia. If approved, Xywav would become the first treatment for the disorder. Will Jazz Pharmaceuticals be able to hold onto its narcolepsy drug status and successfully switch over its Xyrem patients onto its lower-sodium Xywav formulation, a formulation that may also be approved for idiopathic hypersomnia? Monitor along with Earnest Healthcare Claims data.