Phase 3 REVITALYZ Trial of Once-Nightly Sodium Oxybate in Idiopathic Hypersomnia Finishes Enrollment

A clinical readout from the phase 3 REVITALYZ trial (NCT06525077) testing Avadel’s once-nightly sodium oxybate (Lumryz) treatment in patients with idiopathic hypersomnia (IH) is expected in Q2 2026, as the company recently announced completed enrollment for the study and its final patients.¹

REVITALYZ, which began dosing in August 2024, is a double-blind, placebo-controlled, randomized withdrawal study of approximately 150 patients with IH who receive either once-nightly sodium oxybate or placebo for 42 weeks. The study’s primary end point, change in Epworth Sleepiness Scale (ESS) total score, will be assessed at 14 weeks.

"Idiopathic hypersomnia is a profoundly underserved, serious sleep disorder marked by extreme difficulty waking up, known as sleep inertia, and persistent, overwhelming daytime sleepiness," Richard K. Bogan, MD, FCCP, FAASM, principal of Bogan Sleep Consultants and associate clinical professor at the University of South Carolina School of Medicine, said in a statement.¹ "People living with IH need additional treatments. With a therapeutic dose designed to cover the nocturnal sleep period due to its extended-release formulation, LUMRYZ could become a valuable option, if approved, for these patients."

To date, there is only 1 FDA-approved option for IH: Jazz Pharmaceuticals’ Xywav, a combination of calcium, magnesium, potassium, and sodium oxybates, which gained greenlight in 2021. Lumryz, which came into market in May 2023, became the first and only FDA-approved once-nightly oxybate as an option for cataplexy or excessive daytime sleepiness in adults with narcolepsy.²

Pregnant, breastfeeding, or lactating individuals are excluded from REVITALYZ. Additional exclusion criteria include hypersomnia attributable to other medical, behavioral, sleep-related, or psychiatric conditions; untreated or inadequately treated sleep apnea with an apnea–hypopnea index greater than 15; clinically significant parasomnias; a history or presence of seizures or head trauma; and succinic semialdehyde dehydrogenase deficiency.

"Completion of enrollment in the REVITALYZ trial marks an important step forward for this community," Jennifer Gudeman, PharmD, senior vice president of Medical and Clinical Affairs at Avadel, said in a statement.¹ "The clinical benefits of LUMRYZ have already positively impacted the narcolepsy community, and we are optimistic our extended-release sodium oxybate has potential to be a meaningful treatment for the IH community as well, if approved by the FDA."

Lumyrz in Pediatric Narcolepsy

Slightly more than a year after its original approval, Avadel’s once-nightly formulation gained an expanded indication in pediatric patients 7 years of age and older with narcolepsy. The drug, which addresses the cardinal symptoms of narcolepsy, cataplexy, and excessive daytime sleepiness, is available through a restricted program under a Risk Evaluation and Mitigation Strategy called the Lumryz REMS.³

Following the approval, NeurologyLive® sat down with pediatric sleep disorders specialist Anne Marie Morse, DO, FAASM, to discuss the significance of a new treatment for pediatric patients with narcolepsy. As part of our Mind Moments podcast, Morse commented on the clinical considerations behind this once-nightly formulation of sodium oxybate, and how it should be used going forward. In the link below, she stresses the careful use of sodium oxybate treatments, noting that they may have significant impact on patients with narcolepsy and should not be only reserved for the most severe cases.

REFERENCES
1. Avadel Pharmaceuticals Announces Completion of Enrollment in Phase 3 REVITALYZ™ Trial in Idiopathic Hypersomnia. News release. Avadel Pharmaceuticals. December 18, 2025. Accessed December 23, 2025. https://www.globenewswire.com/news-release/2025/12/18/3207569/0/en/Avadel-Pharmaceuticals-Announces-Completion-of-Enrollment-in-Phase-3-REVITALYZ-Trial-in-Idiopathic-Hypersomnia.html
2. Avadel Pharmaceuticals announces final FDA approval of Lumryz (sodium oxybate) for extended-release oral suspension as the first and only once-at-bedtime oxybate for cataplexy or excessive daytime sleepiness in adults with narcolepsy. News release. Avadel Pharmaceuticals. May 1, 2023. Accessed December 23, 2025. https://www.globenewswire.com/news-release/2023/05/01/2658536/0/en/Avadel-Pharmaceuticals-Announces-Final-FDA-Approval-of-LUMRYZ-sodium-oxybate-for-Extended-Release-Oral-Suspension-as-the-First-and-Only-Once-at-Bedtime-Oxybate-for-Cataplexy-or-Exc.html
3. Avadel Pharmaceuticals Announces FDA Approval of LUMRYZ™ (sodium oxybate) Extended-Release Oral Suspension (CIII) for the Treatment of Cataplexy or Excessive Daytime Sleepiness in Patients 7 Years of Age and Older with Narcolepsy. News Release. Avadel Pharmaceuticals. Published October 17, 2024. Accessed December 23, 2025. https://investors.avadel.com/news-releases/news-release-details/avadel-pharmaceuticals-announces-fda-approval-lumryztm-sodium