Avadel Pharmaceuticals plc, a biopharmaceutical company focused on transforming medicines to transform lives, announced on June 5 2025, that LUMRYZTM has been granted Orphan Drug Designation (ODD) from the U.S. Food & Drug Administration (FDA) for the treatment of Idiopathic Hypersomnia (IH). Specifically, ODD was granted based on the plausible hypothesis that LUMRYZ may be clinically superior to the same drug(s) already approved for the same indication, because LUMRYZ may provide a major contribution to patient care due to its once-nightly dosing for patients with IH, a chronic sleep disorder that requires potentially lifelong treatment.
“We are pleased that LUMRYZ has been granted Orphan Drug Designation for the treatment of IH, and this recognition reinforces our strategy to develop differentiated therapies for patients with rare sleep disorders,” said Greg Divis, Chief Executive Officer of Avadel Pharmaceuticals. “Receipt of ODD highlights the unique value of our next-generation, extended-release oxybate and its potential for IH patients, if approved. We continually hear from clinicians and patients of the substantial need for an extended-release oxybate for this patient population – a population who suffers from profound sleep inertia, making waking up in the middle of the night an even greater challenge than in narcolepsy. With continued progress in our pivotal Phase 3 REVITALYZ trial, an established commercial foundation in narcolepsy, and a relentlessly devoted team, we are well-positioned to advance LUMRYZ in IH with the goal of ultimately transforming the IH treatment landscape, if approved.”
IH is a rare and debilitating sleep disorder characterized by excessive daytime sleepiness not attributable to any other medical conditions. LUMRYZ is currently being evaluated for the treatment of IH in the REVITALYZ™ trial, which is a double-blind, placebo-controlled, randomized withdrawal, multicenter Phase 3 study designed to evaluate the efficacy and safety of LUMRYZ when given as a once-at-bedtime dose. The study will enroll approximately 150 adults who are diagnosed with IH. REVITALYZ enrollment is open for both participants switching from immediate-release oxybates as well as those not currently taking oxybates, and is on track to be completed by year end 2025.
Orphan Drug Designation is granted by the FDA to support drug development for rare diseases and is assigned to drugs and biologics that demonstrate promise for the diagnosis and/or treatment of rare diseases or conditions that affect fewer than 200,000 people in the U.S. The designation can provide several benefits for the development and commercialization of indicated compounds and medicines which include eligibility for a seven-year period of market exclusivity in the U.S. following product approval, FDA assistance in clinical trial design and an exemption from FDA user fees.
About LUMRYZ™ (sodium oxybate) for extended-release oral suspension
LUMRYZ is an extended-release sodium oxybate medication approved by the FDA on May 1, 2023, as the first and only once-at-bedtime treatment for cataplexy or excessive daytime sleepiness (EDS) in adults with narcolepsy. On October 16, 2024, LUMRYZ was additionally approved as a once-at-bedtime treatment for cataplexy or EDS in pediatric patients 7 years of age and older with narcolepsy.
The FDA approval of LUMRYZ was supported by results from REST-ON™, a randomized, double-blind, placebo-controlled, pivotal Phase 3 trial in adults with narcolepsy. LUMRYZ demonstrated statistically significant and clinically meaningful improvements in the three co-primary endpoints: EDS (MWT), clinicians’ overall assessment of patients’ functioning (CGI-I), and cataplexy attacks, for all three evaluated doses when compared to placebo.
With its approvals in May 2023 and October 2024, the FDA also granted 7 years of Orphan Drug Exclusivity to LUMRYZ for the treatment of cataplexy or EDS in adults with narcolepsy and in pediatric patients 7 years of age and older with narcolepsy (respectively) due to a finding of clinical superiority of LUMRYZ relative to currently available oxybate treatments. In particular, the FDA found that LUMRYZ makes a major contribution to patient care over currently available, twice-nightly oxybate products by providing a once-nightly dosing regimen that avoids nocturnal arousal to take a second dose.
LUMRYZ is only currently approved for the treatment of cataplexy or EDS in patients 7 years of age and older with narcolepsy, and Avadel does not sell LUMRYZ for any indication beyond narcolepsy.
