A Switch Study From High-Sodium Oxybate to Xywav to Evaluate Changes in Blood Pressure in Participants With Narcolepsy
XYLO
An Open-Label, Multicenter Switch Study Evaluating Changes in Blood Pressure in Participants With Narcolepsy Switching From High-Sodium Oxybate to Xywav
1 other identifier
interventional
155
5 countries
43
Brief Summary
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_4
Started Jun 2023
43 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
May 12, 2023
CompletedFirst Posted
Study publicly available on registry
May 22, 2023
CompletedStudy Start
First participant enrolled
June 26, 2023
CompletedPrimary Completion
Last participant's last visit for primary outcome
February 25, 2025
CompletedStudy Completion
Last participant's last visit for all outcomes
March 10, 2025
CompletedResults Posted
Study results publicly available
April 24, 2026
CompletedApril 24, 2026
April 1, 2026
1.7 years
May 12, 2023
February 25, 2026
April 3, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Change From Baseline to End of Treatment (EOT) Visit on the 24-hour Average Systolic Blood Pressure (SBP) in mmHg
Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks
Secondary Outcomes (3)
Change From Baseline to EOT Visit on the Daytime Average SBP in mmHg
Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks
Change From Baseline to EOT Visit on the Seated Resting Average SBP in mmHg
Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks
Change From Baseline to EOT Visit on the Nighttime Average SBP in mmHg
Baseline (Screening) and End of Treatment (EOT) Visit, up to 6 weeks
Study Arms (1)
JZP258
EXPERIMENTALEligible participants will be switched, on a gram-for-gram basis, from their prescribed twice-nightly high-sodium oxybate (such as xyrem) to Xywav. Participants who, in the opinion of the investigator, require an adjustment to their Xywav dosing, can increase or decrease their dose by 1.5 grams per night as long as the participant's total nightly dose is between 6 to 9 grams per night.
Interventions
0.5 g/ml calcium, magnesium, potassium, and sodium oxybates oral solution
Eligibility Criteria
You may qualify if:
- 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.
You may not qualify if:
- 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.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (43)
Science 37
Culver City, California, 90230, United States
M3 Wake Research
Encino, California, 91436, United States
So Cal Clinical Research
Huntington Beach, California, 92647, United States
Long Beach Research Institute
Lakewood, California, 90805, United States
Stanford School of Medicine
Redwood City, California, 94063, United States
TriValley Sleep Center
San Ramon, California, 94583, United States
SDS Clinical Trials, Inc.
Santa Ana, California, 92705, United States
FWD Clinical Research
Boca Raton, Florida, 33486, United States
Meris Clinical Research, LLC
Brandon, Florida, 33511, United States
Ocean Wellness Center
Miami, Florida, 33169, United States
Serenity Research Center LLC
Miami, Florida, 33176, United States
Florida Pediatric Research Institute, LLC
Orlando, Florida, 32804, United States
Sleep Practitioners, LLC
Macon, Georgia, 31210, United States
Saltzer Medical Group
Nampa, Idaho, 83686, United States
University of Louisville
Louisville, Kentucky, 40202, United States
University of Maryland Medical Center
Baltimore, Maryland, 21201, United States
Neurocare, Inc
Newton, Massachusetts, 02459, United States
Sparrow Health System
Lansing, Michigan, 48911, United States
Bryan Medical Center
Lincoln, Nebraska, 68506, United States
Henderson Clinical Trials LLC
Henderson, Nevada, 89052, United States
Advanced Respiratory and Sleep Medicine, PLLC
Huntersville, North Carolina, 28078, United States
Intrepid Research, LLC
Cincinnati, Ohio, 45245, United States
University Hospitals Cleveland Medical Center
Cleveland, Ohio, 44106, United States
Ohio Sleep Medicine and Neuroscience
Dublin, Ohio, 43017, United States
OHSU Hospital
Portland, Oregon, 97239, United States
Abington Neurological Associates, LTD
Abington, Pennsylvania, 19001, United States
Bogan Sleep Consultants, LLC
Columbia, South Carolina, 29201, United States
Velocity Clinical Research, Greenville
Greenville, South Carolina, 29615, United States
Clinical Research of Rock Hill
Rock Hill, South Carolina, 29732, United States
FutureSearch Trials of Neurology
Austin, Texas, 78731, United States
Sleep Therapy & Research Center
San Antonio, Texas, 78229, United States
Antwerp University Hospital (UZA)
Edegem, 2650, Belgium
Private Practice RESPISOM Namur
Namur, 5101, Belgium
Hopital Gui de Chauliac
Montpellier, Herault, 34295, France
CHU de Grenoble - Hôpital Albert Michallon
Grenoble, Isere, 38043, France
CHU Nantes - Hôtel Dieu
Nantes, Loire Atlantique, 44093, France
IRCCS Istituto de Scienze Neurologiche di Bologna (ISNB)
Bologna, 40139, Italy
Ospedale San Raffaele (San Raffaele Turro)
Milan, 20127, Italy
Azienda Ospedaliera Universitaria Policlinico Tor Vergata
Roma, 00133, Italy
Hospital Universitario Araba - Sede Santiago
Vitoria-Gasteiz, Alava, 01004, Spain
Hospital Universitari Vall d'Hebron
Barcelona, 08035, Spain
Hospital General de Castellon
Castellon, 12004, Spain
Hospital Universitario Clinico San Carlos
Madrid, 28040, Spain
Related Publications (1)
White WB, Kovacs RJ, Alexander JK, Baranak C, Nichols DA, Fuller DS, Dai J, Whalen M, Ajayi A, Hutchinson B, Dauvilliers Y, Somers VK. Effects of High- Versus Low-Sodium Oxybate on Blood Pressure in Patients With Narcolepsy. Hypertension. 2025 Dec;82(12):2162-2171. doi: 10.1161/HYPERTENSIONAHA.125.25730. Epub 2025 Oct 15.
PMID: 41090230DERIVED
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Results Point of Contact
- Title
- Clinical Trial Disclosure & Transparency
- Organization
- Jazz Pharmaceuticals Inc.
Publication Agreements
- PI is Sponsor Employee
- No
- Restrictive Agreement
- No
Study Design
- Study Type
- interventional
- Phase
- phase 4
- Allocation
- NA
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
May 12, 2023
First Posted
May 22, 2023
Study Start
June 26, 2023
Primary Completion
February 25, 2025
Study Completion
March 10, 2025
Last Updated
April 24, 2026
Results First Posted
April 24, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
In accordance with ICMJE requirements, Jazz Pharmaceuticals may provide qualified external researchers access to individual participant data (IPD) and clinical trial data that underlie the results of this trial upon request. Qualified researchers can submit a request on https://www.jazzpharma.com/science/clinical-trial-data-sharing/ as outlined. Jazz Pharmaceuticals reserves the right not to consider a request. For inquiries about Jazz's data sharing policy contact clinicaldatasharing@jazzpharma.com.