Overviewing the XYLO Study and Low-Sodium Oxybate’s Impact on Blood Pressure: Phil Jochelson, MD

WATCH TIME: 4 minutes

"We believe that sodium load has the potential to increase your blood pressure when taken chronically over time. Sodium burden will be tremendous over the lifetime of a patient, but in this instance, we’re trying to show a reduction in blood pressure."

Narcolepsy is a chronic, long-term neurological disorder characterized by a decreased ability to regulate sleep-wake cycles. There are key components of the disease that are likely related to cardiovascular disease risk. For instance, narcolepsy caused changes to blood pressure during the night, which may increase the risk for cardiovascular problems. In addition, patients with narcolepsy also have higher rates of diabetes, obesity, depression, and other sleep disorders, all of which can contribute to a greater risk of cardiovascular disease.

In 2020, the FDA made a major decision, approving Jazz Pharmaceuticals’ low-sodium oxybate (Xywav) as a medication for cataplexy or excessive daytime sleepiness in patients 7 year of age or older with narcolepsy. The oxybate product contains a unique composition of cations resulting in 92% less sodium, or approximately 1000 to 1500 mg/night, than sodium oxybate (Xyrem; Jazz), the only approved agent at the time. With the approval, it helped patients taking sodium oxybate better align with daily sodium intake recommendations including those by the American Heart Association.

Years later, at the 2024 SLEEP Annual Meeting, investigators presented the outline of a new study, dubbed XYLO, that assesses the effects of switching from high-sodium to low-sodium oxybate on blood pressure in patients with narcolepsy. Specifically, the open-label study will evaluate cardiovascular risks associated with high sodium intake while maintaining treatment efficacy.

Following the meeting, NeurologyLive^® sat down with Phil Jochelson, MD, therapeutic head for Clinical Development Neuroscience at Jazz Pharmaceuticals, sat down to provide an overview of the unique study and some of the main goals behind it. He spoke on how the study will evaluate changes in blood pressure and the reasons behind choosing a 3.5 mL reduction as the primary target for patients switching treatments. Furthermore, he explained why changes in sodium load have a bidirectional relationship with blood pressure, and why switching treatments may ultimately help patients in the long-term.

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