JZP258 for Narcolepsy

No longer recruiting at 35 trial locations

Overseen By Clinical Trial Manager

Age: 18+

Sex: Any

Trial Phase: Phase 4

Sponsor: Jazz Pharmaceuticals

Must be taking: Anticataplectics, Alerting agents

Must not be taking: Alcohol, Sedative hypnotics

Disqualifiers: Sleep-disordered breathing, Major depressive episode, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines the safety and effectiveness of the drug XYWAV (also known as JZP258) for individuals with narcolepsy or idiopathic hypersomnia, a condition causing excessive sleepiness without a known cause. The goal is to assess how well this treatment alleviates daytime sleepiness and improves overall daily functioning. Ideal participants are those experiencing significant daytime sleepiness due to these conditions, particularly if they are not currently taking similar medications. As a Phase 4 trial, this research aims to understand how this FDA-approved and proven effective treatment can benefit more patients.

Do I have to stop taking my current medications for the trial?

You may need to stop taking certain medications that interact with the trial drug, XYWAV, such as alcohol, sedative hypnotics, or those causing sedation. If you're on anticataplectics or alerting agents, you should maintain the same dosage during the study.

What is the safety track record for XYWAV?

Research has shown that XYWAV, also known as JZP258, is generally safe for people with narcolepsy. Studies have found that the most common side effects are mild, including nausea, headache, dizziness, anxiety, trouble sleeping, and reduced appetite. At least 5% of patients reported these side effects. XYWAV is already approved for treating narcolepsy and contains less sodium than the previous version, which benefits those who need to monitor their sodium intake. This approval and its use in current treatments provide reassurance about its safety. ^{1 2 3 4 5}

Why are researchers enthusiastic about this study treatment?

Most treatments for narcolepsy focus on managing symptoms like excessive daytime sleepiness through stimulants or wakefulness-promoting agents. But XYWAV (JZP258) works differently. It is a reformulation of sodium oxybate, designed to have a lower sodium content. This new formulation is exciting because it reduces the potential cardiovascular risks associated with high sodium intake, making it a potentially safer option for those with narcolepsy who are concerned about heart health.

What is the effectiveness track record for XYWAV in treating narcolepsy?

Research shows that XYWAV, the treatment under study in this trial, effectively treats narcolepsy, particularly by reducing cataplexy (sudden muscle weakness) and excessive daytime sleepiness. Studies have found that it contains 92% less sodium than older oxybate medications, offering a healthier option for those concerned about sodium intake. Previous findings suggest that patients who switch to XYWAV experience improvements in blood pressure and sleep quality. The treatment is also approved for narcolepsy in patients aged 7 and older, demonstrating its effectiveness for both children and adults. This track record supports its potential benefits for idiopathic hypersomnia as well. ^{1 2 4 6 7}

Are You a Good Fit for This Trial?

Adults aged 18-75 with idiopathic hypersomnia or narcolepsy, who meet specific diagnostic criteria. Participants should be on a stable dose of anticataplectics/alerting agents for at least one month if applicable, and not planning to change dosages during the study. Those not on oxybate must have significant daytime sleepiness (ESS score >10). Exclusions include unstable medical conditions, certain psychiatric disorders, other untreated sleep disorders, or use of sedating medications.

Inclusion Criteria

I've been on a stable dose of medication for sleepiness or cataplexy for at least 1 month.

I have been diagnosed with IH or narcolepsy according to recognized standards.

I feel very sleepy during the day and my sleepiness score is over 10.

Exclusion Criteria

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

My sleep study shows I have moderate to severe sleep apnea.

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

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants self-administer an oral dose of JZP258 (XYWAV) and titrate to an optimal dosage

12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• XYWAV

Trial Overview The trial is testing JZP258 (XYWAV) to see how safe and effective it is in reducing excessive daytime sleepiness and improving overall function in patients with idiopathic hypersomnia or narcolepsy. The study will monitor participants' sleep patterns using polysomnography and assess their functional outcomes.

How Is the Trial Designed?

Group I: JZP258 Experimental Treatment 1 Intervention

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

XYWAV is already approved in United States for the following indications:

Approved in United States as XYWAV for:

• Cataplexy or excessive daytime sleepiness in people aged seven years of age and older with narcolepsy
• Idiopathic hypersomnia

Who Is Running the Clinical Trial?

Jazz Pharmaceuticals

Lead Sponsor

Trials

252

Recruited

35,100+

Bruce C. Cozadd

Jazz Pharmaceuticals

Chief Executive Officer since 2009

BA in Economics from Yale University, MBA from Stanford University

Dr. Austin

Jazz Pharmaceuticals

Chief Medical Officer since 2023

MD from the Royal College of Surgeons in Ireland

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7953213/

JZP-258) in a placebo-controlled, double-blind, randomized ... Evaluate efficacy and safety of lower-sodium oxybate (LXB), a novel oxybate medication with 92% less sodium than sodium oxybate (SXB).

2. prnewswire.com prnewswire.com/news-releases/jazz-pharmaceuticals-presents-late-breaking-phase-4-data-showcasing-xywav-calcium-magnesium-potassium-and-sodium-oxybates-oral-solution-treatment-outcomes-in-narcolepsy-at-sleep-2025-302476849.html

Jazz Pharmaceuticals Presents Late-Breaking Phase 4 ... First presentation of the Phase 4 XYLO switch study reports blood pressure reductions in patients with narcolepsy when switching from twice-nightly high- to ...

3. accessdata.fda.gov accessdata.fda.gov/drugsatfda_docs/label/2021/021196s036,212690s001s006lbl.pdf

XYWAV® (calcium, magnesium, potassium, and sodium ... XYWAV is indicated for the treatment of cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy. 1.2 Idiopathic ...

4. jcsm.aasm.org jcsm.aasm.org/doi/10.5664/jcsm.11182

Effectiveness and optimization of low-sodium oxybate in ... Effectiveness and optimization of low-sodium oxybate in participants with narcolepsy switching from a high-sodium oxybate: data from the Substitution of ...

5. investor.jazzpharma.com investor.jazzpharma.com/news-releases/news-release-details/jazz-pharmaceuticals-showcases-phase-4-data-demonstrating-xywavr

Jazz Pharmaceuticals Showcases Phase 4 Data ... Jazz Pharmaceuticals Showcases Phase 4 Data Demonstrating Xywav® (calcium, magnesium, potassium, and sodium oxybates) Oral Solution Treatment ...

6. prnewswire.com prnewswire.com/news-releases/jazz-pharmaceuticals-showcases-phase-4-data-demonstrating-xywav-calcium-magnesium-potassium-and-sodium-oxybates-oral-solution-treatment-effects-and-real-world-evidence-at-world-sleep-and-psych-congresses-302562421.html

Jazz Pharmaceuticals Showcases Phase 4 Data ... Xywav is the only oxybate therapy that does not carry a warning in the label related to use in patients sensitive to high sodium intake. Xywav ...

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/33184650/

JZP-258) in a placebo-controlled, double-blind, ... Study objectives: Evaluate efficacy and safety of lower-sodium oxybate (LXB), a novel oxybate medication with 92% less sodium than sodium oxybate (SXB).