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Completed

NCT Number: NCT05869773

A Switch Study From High-Sodium Oxybate to Xywav to Evaluate Changes in Blood Pressure in Participants With Narcolepsy

The aim of this study is to quantify the change in blood pressure when participants with narcolepsy treated with high-sodium oxybate are transitioned to Xywav, a low-sodium oxybate. The results of this study may provide health care providers (HCPs), patients, and payers with important new information regarding BP changes related to differences in sodium content between available oxybates for the treatment of narcolepsy.

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Key information

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Antwerp University Hospital (UZA), Edegem, Belgium

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Key Inclusion Criteria:

  • Participants must be 18 to 70 years of age inclusive, at the time of signing the informed consent.
  • Participants have a documented diagnosis of Type 1 or Type 2 narcolepsy that meets International Classification of Sleep Disorders (ICSD)-3 or Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria.
  • Participants must have been receiving a total dose of high-sodium oxybate (eg, XYREM) of 6 to 9 g/night (inclusive) with twice-nightly dosing for a minimum of 6 consecutive weeks prior to screening.
  • If currently treated with stimulants and/or alerting agents or other medications known to affect BP, participant must have been taking the same dosing regimen for at least 2 months prior to screening and agree to take the same dose throughout the study.
  • If currently taking stable doses of antihypertensive therapies, participant must maintain these treatments at the same dose throughout the study unless otherwise advised by their medical care
  • Participant is male or female. A female participant is eligible to participate if she is not pregnant or breastfeeding, if she is a woman of nonchildbearing potential or is a woman of childbearing potential and using a contraceptive method that is highly effective.

Key Exclusion Criteria:

  • History or presence of any acutely unstable medical condition, behavioral or psychiatric disorder (including active suicidal ideation), or surgical history that could affect the safety of the participant or interfere with study assessments or the ability of the participant to complete the study based on the judgment of the investigator.
  • Presence of significant cardiovascular disease or cardiovascular condition that in the investigator's opinion may jeopardize participant safety in the study, including screening ECG results.
  • Presence of atrial fibrillation detected on screening electrocardiogram (ECG).
  • Presence of resistant hypertension.

Treatment and study plan

JZP258

Drug

0.5 g/ml calcium, magnesium, potassium, and sodium oxybates oral solution

Other names: Xywav

Primary outcomes

  1. Change From Baseline to End of Treatment (EOT) Visit on the 24-hour Average Systolic Blood Pressure (SBP) in mmHg

    Time frame: Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks

Secondary outcomes

  1. Change From Baseline to EOT Visit on the Daytime Average SBP in mmHg

    Time frame: Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks

  2. Change From Baseline to EOT Visit on the Seated Resting Average SBP in mmHg

    Time frame: Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks

  3. Change From Baseline to EOT Visit on the Nighttime Average SBP in mmHg

    Time frame: Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks

Sponsors and collaborators

Lead sponsor

Jazz Pharmaceuticals

Industry

Registry information

Official study title

An Open-Label, Multicenter Switch Study Evaluating Changes in Blood Pressure in Participants With Narcolepsy Switching From High-Sodium Oxybate to Xywav

Acronym: XYLO

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
May 22, 2023
Registry last updated
Apr 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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