A Study to Investigate the Effect of XYWAV on Sleepiness, Polysomnography, and Functional Outcomes in Participants With Idiopathic Hypersomnia or Narcolepsy

NCT05875974 | Completed Phase 4 FDA Drug

• 1 other identifier: JZP258-407
• Study Type: interventional
• Target: 207
• Locations: 2 countries
• Sites: 32

Brief Summary

This study will assess the safety and efficacy of JZP258 (XYWAV) on sleepiness, polysomnography, and functional outcomes in patients with idiopathic hypersomnia (IH) or narcolepsy.

Conditions

Idiopathic Hypersomnia; Narcolepsy

Keywords

Idiopathic Hypersomnia; Narcolepsy; Excessive daytime sleepiness; Polysomnography; JZP258; XYWAV; Oxybate

Outcome Measures

Primary Outcomes (1)

• Epworth Sleepiness Scale (ESS) Total Score in Participants With IH and Narcolepsy Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-36 weeks)

Secondary Outcomes (10)

• Idiopathic Hypersomnia Severity Scale (IHSS) Total Score in Participants With IH Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-21 weeks)

• Number of Stage Shifts of Sleep in Participants With Narcolepsy Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-36 weeks)

• Duration of Sleep Stages in Participants With Narcolepsy Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-36 weeks)

• Number of Nocturnal Awakenings and Nocturnal Arousals in Participants With Narcolepsy Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-36 weeks)

• Percentage of Sleep Stages in Participants With Narcolepsy Treated With XYWAV

  Baseline up to End of Treatment (approximately 10-36 weeks)

Study Arms (1)

JZP258

EXPERIMENTAL

Participants will self-administer an oral dose of JZP258 (XYWAV) as per label and titrate to an optimal dosage for each participant.

Drug: JZP258 (XYWAV)

Interventions

JZP258 (XYWAV) DRUG

Narcolepsy Cohort: Initiate dosage per XYWAV label and titrate to effect. IH Cohort: Initiate dosage per XYWAV label and titrate to effect. Narcolepsy \>9-Gram Cohort: XYWAV titrated to a dosage of \>9 to 12 grams.

JZP258

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Is 18 to 75 years of age (inclusive) at the time of signing the informed consent form (ICF)
• Has a primary diagnosis of IH meeting International Classification of Sleep Disorders, Third Edition (ICSD-3) criteria or narcolepsy (Type 1 or Type 2) meeting ICSD-3 or Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) criteria.
• If not currently taking oxybate medication, has clinically significant symptoms of Excessive daytime sleepiness (EDS) with an ESS score \> 10 at Screening Visit 1. If currently taking oxybate medication, has an ESS score \> 10 at the Baseline Visit 2 polysomnography (after washout period). Note: Not applicable for participants entering the Narcolepsy \>9-gram cohort (see additional criteria below for the Narcolepsy \>9-gram cohort).
• If currently treated with anticataplectics and/or alerting agents, has been taking the same dosage for at least 1 month prior to Screening Visit 1 and has no current plans to adjust the dosage during the study period. Note: Alerting agents refer to either traditional stimulants (eg, amphetamines, methylphenidates) or wake-promoting agents (eg, modafinil, pitolisant, solriamfetol).
• Is on a current treatment regimen including XYWAV at a dosage of 9 grams

You may not qualify if:

• Shows evidence of a previous untreated or inadequately treated sleep disorder considered by the investigator to negatively impact the conduct of the study, including sleep-disordered breathing, parasomnias, circadian rhythm sleep disorders, or restless legs syndrome determined by a previous sleep-laboratory diagnosis or interview utilizing modules of the Diagnostic Interview for Sleep Patterns and Disorders.
• Shows evidence of untreated or inadequately treated sleep-disordered breathing during Baseline Visit 2 polysomnography defined as an Apnea/Hypopnea Index (AHI) \> 10, using the US Centers for Medicare and Medicaid Services rules (CMS.gov).
• Has a history or presence of any unstable or clinically significant medical condition (chronic pain condition that may impact sleep), behavioral or psychiatric disorder (including active suicidal ideation or current or past \[within 1 year\] major depressive episode), or history or presence of another neurologic disorder or surgical history that might affect the participant's safety and/or interfere with the conduct of the study, in the opinion of the investigator.
• Has recently taken (ie, within 1 month prior to screening), is taking, or plans to take any of the following:
• A substance or medication contraindicated with XYWAV use, ie. specifically alcohol and sedative hypnotics
• A medication with a known drug-drug interaction with XYWAV
• A medication that may have similar EEG effects to XYWAV
• Medications known to have clinically significant CNS sedative effects
• Other medications, natural health products, or substances from which the participant experiences clinically significant sedation
• Any past or current medical conditions or experience that, in the investigator's clinical judgment, would preclude further increases in the current oxybate medication dosage beyond 9 grams

Sponsors & Collaborators

• Jazz Pharmaceuticals: lead

Study Sites (32)

Sleep Disorders Center of Alabama

Birmingham, Alabama, 35213, United States

Location

Perseverance Research Center, LLC

Scottsdale, Arizona, 85253, United States

Location

Amnova Clinical Research

Irvine, California, 92604, United States

Location

Long Beach Research Institute

Lakewood, California, 90805, United States

Location

Santa Monica Clinical Trials

Los Angeles, California, 90025, United States

Location

Stanford School of Medicine

Redwood City, California, 94063, United States

Location

TriValley Sleep Center

San Ramon, California, 94583, United States

Location

SDS Clinical Trials, Inc.

Santa Ana, California, 92705, United States

Location

Meris Clinical Research, LLC

Brandon, Florida, 33511, United States

Location

PharmaDev Clinical Research Institute, LLC

Miami, Florida, 33176, United States

Location

Florida Hospital for Children

Winter Park, Florida, 32789, United States

Location

NeuroTrials Research, Inc.

Atlanta, Georgia, 30328, United States

Location

Centricity Research Rincon - DBA IACT Health Southeast Lung Associates Research

Rincon, Georgia, 31326, United States

Location

Neurocare, Inc., dba Neurocare Center for Research

Newtown, Massachusetts, 02459, United States

Location

Clinical Neurophysiology Services, P.C.

Sterling Heights, Michigan, 48314, United States

Location

St. Lukes Hospital Medical Center

Chesterfield, Missouri, 63017, United States

Location

Clinical Research of Gastonia

Gastonia, North Carolina, 28054, United States

Location

Stern Research Partners, LLC

Huntersville, North Carolina, 28078, United States

Location

CTI Clinical Research Center

Cincinnati, Ohio, 45212, United States

Location

Intrepid Research

Cincinnati, Ohio, 45245, United States

Location

Cleveland Clinic Main Campus - Clinical Research Unit

Cleveland, Ohio, 44195, United States

Location

Ohio Sleep Medicine and Neuroscience Institute

Dublin, Ohio, 43017, United States

Location

Abington Neurological Associates, LTD

Abington, Pennsylvania, 19001, United States

Location

Geisinger Clinic

Scranton, Pennsylvania, 18510, United States

Location

Bogan Sleep Consultants, LLC

Columbia, South Carolina, 29201, United States

Location

FutureSearch Trials of Neurology

Austin, Texas, 78731, United States

Location

Comprehensive Sleep Medicine Associates

Houston, Texas, 77030, United States

Location

Sleep Therapy & Research Center

San Antonio, Texas, 78229, United States

Location

Tricoastal Narcolepsy and Sleep Disorders Center

Sugar Land, Texas, 77479, United States

Location

Heritage Medical Research Clinic, University of Calgary

Calgary, Alberta, T2N 4Z6, Canada

Location

AMNDX Inc

Markham, Ontario, L3R 1A3, Canada

Location

Johda Tishon Inc

Toronto, Ontario, M5S 3A3, Canada

Location

MeSH Terms

Conditions

Idiopathic Hypersomnia; Narcolepsy; Disorders of Excessive Somnolence

Condition Hierarchy (Ancestors)

Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders

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 16, 2023
• First Posted: May 25, 2023
• Study Start: July 27, 2023
• Primary Completion: March 13, 2025
• Study Completion: March 13, 2025
• Last Updated: July 17, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (3); US (29)