FDA Approves Once-Nightly Lumryz for Patients With Narcolepsy

Credit: Avadel.
Lumryz is an extended-release formulation of sodium oxybate.

The Food and Drug Administration (FDA) has granted final approval to Lumryz (sodium oxybate) for the treatment of cataplexy or excessive daytime sleepiness in adults with narcolepsy.

Lumryz is an extended-release formulation of sodium oxybate, a central nervous system depressant. Its therapeutic effects are believed to be mediated through GABAB actions at noradrenergic and dopaminergic neurons, as well as at thalamocortical neurons.

The approval was based on by data from the phase 3 REST-ON study (ClinicalTrials.gov: NCT02720744), which included 212 patients with narcolepsy. Study participants were randomly assigned to receive Lumryz (titrated to 4.5g, 6.0g, 7.5g, and 9.0g) or placebo once nightly for 13 weeks.

The co-primary endpoints of the study included improvements on the Maintenance of Wakefulness Test (MWT), Clinical Global Impression of Improvement (CGI-I) in daytime sleepiness, and mean weekly cataplexy attacks, recorded on the Sleep and Symptom Daily Diary.

Results showed that patients treated with Lumryz 9g achieved highly significant and clinically meaningful improvements across all 3 endpoints compared with placebo at week 13:

  • MWT: 10.82 minutes vs 4.7 minutes; difference from placebo: 6.1 (95% CI, 3.52-8.75); P <.001.
  • CGI-I (% of patients much/very much improved): 73% vs 32%; odds ratio 5.6 (95% CI, 2.76-11.23); P <.001.
  • Mean weekly cataplexy attacks: -11.51 vs -4.9; difference from placebo: -6.7 (95% CI, -9.32, -3.98); P <.001.

Statistically significant improvements on all 3 endpoints were also observed with the 6g (week 3) and 7.5g (week 8) doses of Lumryz compared with placebo (P <.001).

The most common adverse reactions reported with treatment included nausea, dizziness, enuresis, headache, and vomiting.

“This long-awaited therapy for people living with narcolepsy fills a critical unmet need by avoiding the burden of a second middle-of-the-night dose that immediate-release oxybate products require,” said Michael J. Thorpy, MD, an investigator from the REST-ON phase 3 trial and Director at the Sleep-Wake Disorders Center at Montefiore Medical Center and Professor of Neurology at the Albert Einstein College of Medicine. “The once-at-bedtime dosing regimen of Lumryz may help restore a more natural sleep-wake cycle.”

Lumryz is supplied in packets with granules that are mixed with water to create an oral suspension. The carton also contains a mixing cup. The dosage strengths include 4.5g, 6g, 7.5g, and 9g per packet of sodium oxybate. The product is taken orally as a single dose at bedtime.

Lumryz is expected to be available in early June.


  1. 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. May 1, 2023. 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.
  2. Lumryz. Package insert. Avadel; 2023. Accessed May 1, 2023. https://www.avadel.com/lumryz-prescribing-information.pdf.