Small Molecule · LUMRYZ

LUMRYZ (sodium oxybate extended-release)

Phase 3Alkermes plc (ALKS)

LUMRYZ is a once-nightly, extended-release oral-suspension formulation of sodium oxybate (the sodium salt of gamma-hydroxybutyrate, GHB; developmental code FT218). It is a CNS depressant acting as a GABA-B receptor agonist. LUMRYZ is FDA-approved for the treatment of cataplexy or excessive daytime sleepiness in patients 7 years and older with narcolepsy, and is being developed for idiopathic hypersomnia. Originally developed by Avadel Pharmaceuticals; Avadel was acquired by Alkermes plc (acquisition completed 2026-02-12).

Also known as: LUMRYZ, FT218, FT-218, sodium oxybate extended-release, sodium oxybate, once-nightly sodium oxybate, gamma-hydroxybutyrate sodium salt, 502-85-2

Modality
Small molecule
Chemical class
hydroxy fatty acid, short-chain fatty acid
DEA schedule
Schedule III
Chemistry
Achiral
Mechanism
GABA-B receptor agonist
Highest phase
Phase 3
Lead indication
Idiopathic Hypersomnia
Developer
Alkermes plc (ALKS)
Trials
1 tracked

Mechanism of action

Sodium oxybate is the sodium salt of gamma-hydroxybutyrate (GHB), an endogenous metabolite of GABA. Its CNS-depressant and sleep-promoting effects are mediated principally by agonist activity at GABA-B receptors (low, millimolar potency), with additional activity at the distinct high-affinity GHB receptor. Agonism of GABA-B receptors enhances inhibitory neurotransmission, consolidating slow-wave sleep and reducing next-day sleepiness.

TargetActionAffinity
GABA-B receptorprimaryGABBR1Agonist
GHB receptorGHBRAgonist

Formulations

FormulationRouteRegimenPharmacokinetics
LUMRYZ (sodium oxybate extended-release oral suspension)extended-release (once-at-bedtime) oral suspension; sodium oxybate granules reconstituted in water
4.5 g, 6 g, 7.5 g, or 9 g sodium oxybate per single bedtime dose (packets)
OralOnce nightlyTmax 1.5 h

Development timeline

Phase 3Aug 2024 – May 2026
  1. metREVITALYZ Phase 3 positive topline: LUMRYZ met the primary ESS endpoint and all key secondary endpoints (PGI-C, IHSS, ESS worsening on placebo), each p<0.0001, in adults with idiopathic hypersomnia; sNDA planned by end of 2026.
  2. REVITALYZ Phase 3 study reached primary completion / completion (registry actual date).
  3. REVITALYZ Phase 3 study (NCT06525077) in idiopathic hypersomnia initiated (registry start date); sponsored by Avadel Pharmaceuticals.

LUMRYZ (sodium oxybate extended-release) for Idiopathic Hypersomnia

Phase 3ActiveIdiopathic Hypersomnia indication →

LUMRYZ (once-nightly sodium oxybate ER) is in Phase 3 development for idiopathic hypersomnia. The pivotal REVITALYZ study (NCT06525077), a double-blind, placebo-controlled, randomized-withdrawal, multicenter trial, reported positive topline results on 2026-05-12, meeting its primary endpoint (change in Epworth Sleepiness Scale, p<0.0001) and all key secondary endpoints (PGI-C, IHSS, and ESS worsening on placebo, each p<0.0001). Alkermes plans to file a supplemental New Drug Application (sNDA) with the FDA by the end of 2026. LUMRYZ is already FDA-approved for cataplexy or excessive daytime sleepiness in patients 7+ with narcolepsy, which is the lead indication; idiopathic hypersomnia is a label-expansion program.

Readouts

  • 2026-05-12ReportedTopline datametNCT06525077

    REVITALYZ Phase 3 positive topline: LUMRYZ met the primary ESS endpoint and all key secondary endpoints (PGI-C, IHSS, ESS worsening on placebo), each p<0.0001, in adults with idiopathic hypersomnia; sNDA planned by end of 2026.

Clinical trials

NCT06525077REVITALYZPhase 3Completedn=157

A Double-blind, Placebo-controlled, Randomized Withdrawal, Multicenter Study of the Efficacy and Safety of FT218 in the Treatment of Idiopathic Hypersomnia (IH) (REVITALYZ)

Started Aug 2024· Primary completion Mar 2026

metsecondaryIdiopathic Hypersomnia Severity Scale (IHSS) total score (<0.0001)

Key secondary endpoint met: participants randomized to placebo had statistically significant worsening in IHSS total score vs those continuing LUMRYZ (p<0.0001).

metprimaryChange in total Epworth Sleepiness Scale (ESS) score (end of stable-dose period to end of double-blind randomized-withdrawal period) (<0.0001)

LUMRYZ met the primary endpoint: statistically significant improvement in excessive daytime sleepiness vs placebo measured by change in total ESS score during the randomized-withdrawal period (p<0.0001). Participants randomized to placebo showed significant worsening in ESS vs those continuing LUMRYZ.

metsecondaryPatient Global Impression of Change (PGI-C) (<0.0001)

Key secondary endpoint met: participants randomized to placebo had statistically significant worsening on PGI-C vs those continuing LUMRYZ (p<0.0001).

Identifiers

Sources

  1. Alkermes Announces Positive Topline Results From REVITALYZ Phase 3 Study Evaluating LUMRYZ (sodium oxybate) Extended-Release in Adults With Idiopathic Hypersomnia — Alkermes plc
  2. GABAB1 subunit (GABBR1) - GABA-B receptors — IUPHAR/BPS Guide to Pharmacology
  3. LUMRYZ (sodium oxybate) for extended-release oral suspension — FDA label (DailyMed) — DailyMed / FDA
  4. Safety and Efficacy of FT218 in Idiopathic Hypersomnia (REVITALYZ) - NCT06525077 — ClinicalTrials.gov
  5. Sodium Oxybate - StatPearls (mechanism: GHB / GABA-B) — StatPearls, NCBI Bookshelf