Jazz Pharmaceuticals Reports Positive Phase 4 Trial Results for Narcolepsy Drug.

Jazz Pharmaceuticals announced that its narcolepsy drug has met the primary endpoint in a Phase 4 trial. The drug is intended to treat cataplexy or excessive daytime sleepiness in patients with narcolepsy aged seven and older. Jazz Pharmaceuticals is a biotech company with a portfolio of marketed products including Xywav, Xyrem, Epidiolex, Rylaze, Zepzelca, Defitelio, and Vyxeos.

Jazz Pharmaceuticals plc (NASDAQ: JAZZ) announced significant late-breaking Phase 4 data at the SLEEP 2025 conference, demonstrating the effectiveness of its narcolepsy drug, Xywav. The data, presented in two oral presentations, highlight the treatment outcomes of Xywav in patients with narcolepsy.

The Phase 4 XYLO switch study, involving 43 participants, showed a clinically meaningful reduction in mean 24-hour ambulatory systolic blood pressure (SBP) after switching from twice-nightly high-sodium oxybate to low-sodium Xywav. The mean change in SBP was -4.1 mmHg (P=0.0019), with similar reductions in daytime and seated resting SBP [1].

The DUET trial, an intermediate analysis of 24 adults with narcolepsy, showed improvements in excessive daytime sleepiness (EDS) and narcolepsy severity scale scores. Participants taking 9-12 grams of Xywav twice-nightly experienced reduced EDS and improved narcolepsy severity scores compared to baseline [1].

These findings underscore the importance of monitoring cardiovascular indicators and minimizing sodium intake in narcolepsy patients. Xywav, the only low-sodium oxybate approved by the FDA, offers a reduced sodium burden compared to high-sodium oxybates, such as Xyrem. The drug is indicated for cataplexy or EDS in patients 7 years of age and older with narcolepsy and for adults with idiopathic hypersomnia [1].

The results presented at SLEEP 2025 are part of Jazz Pharmaceuticals' ongoing commitment to advancing narcolepsy treatment and improving the lives of patients living with this chronic, debilitating condition.

References:
[1] Jazz Pharmaceuticals plc. (2025). Jazz Pharmaceuticals Presents Late-Breaking Phase 4 Data Showcasing Xywav® (calcium, magnesium, potassium, and sodium oxybates) Oral Solution Treatment Outcomes in Narcolepsy at SLEEP 2025. Retrieved from https://investor.jazzpharma.com/news-releases/news-release-details/jazz-pharmaceuticals-presents-late-breaking-phase-4-data