Low-Sodium Narcolepsy Treatment Safe & Effective in Patients with Cardiovascular/Cardiometabolic Comorbidities

Study results presented at the 2024 SLEEP meeting of the Associated Professional Sleep Societies demonstrated that Xywav (low-sodium oxybate; Jazz Pharmaceuticals, Dublin, Ireland) treatment for narcolepsy was safe and effective for those with cardiovascular (CV) and cardiometabolic (CM) comorbidities. Xywav contains 92% less sodium than high-sodium oxybates.

Researchers conducted a post hoc analysis of data from a phase 3 trial (NCT03030599) which included 201 participants (69 of whom reported CV/CM comorbidities at baseline) aged 18-70 years with a primary diagnosis of narcolepsy with cataplexy. After an optimized Xywav dose was established (which took up to 12 weeks), participants entered a 2-week stable-dose period (SDP). This was followed by a 2-week double-blind randomized-withdrawal period (DBRWP) in which participants received either placebo or continued Xywav treatment. Outcomes studied included changes in number of cataplexy attacks, Epworth Sleepiness Scale (ESS) scores, Patient Global Impression of Change (PGIc) scores, and treatment-emergent adverse events (TEAEs). Researchers stratified results from participants randomized to either placebo or Xywav into 2 subgroups: those with and those without CV/CM comorbidities.  

• Participants randomized to placebo experienced worsening in ESS scores and reported worse PGIc scores compared with those randomized to Xywav in both subgroups: those with and without CV/CM comorbidities.
• Those randomized to receive placebo without CV/CM comorbidities experienced an increased number of cataplexy attacks compared with those randomized to receive Xywav (median, placebo: 3.0; median, Xywav, 0.00; P<.0001).

Serious TEAEs were reported by 3% of participants with CV/CM comorbidities and 2% of those without.

This study was supported by Jazz Pharmaceuticals.