Takeda’s ORZEYFUL approved in Japan for narcolepsy type 1

Regulatory approval

The Japanese Ministry of Health, Labour and Welfare approved ORZEYFUL (oveporexton) for the treatment of narcolepsy type 1 (NT1) in adults. Takeda, which discovered the compound in Japan, is proceeding with launch preparations. The approval represents the third regulatory clearance for ORZEYFUL globally; it is also approved in China and the United States, with U.S. Drug Enforcement Administration controlled-substance classification currently under review.

Clinical evidence

The MHLW decision was supported by a global Phase 3 programme, including the FirstLight (TAK-861-3001) and RadiantLight (TAK-861-3002) studies. Those trials reported statistically significant and meaningful improvements across the full range of NT1 symptoms assessed versus placebo, including reductions in excessive daytime sleepiness and cataplexy, as well as improvements on secondary measures.

Indication, dosing and safety

ORZEYFUL is an oral orexin receptor 2 (OX2R) agonist designed to restore OX2R signalling linked to orexin deficiency in NT1. The usual adult dose is 1 mg taken orally twice daily—first on awakening and a second dose 3–5 hours later—with escalation to 2 mg twice daily if tolerated and additional efficacy is required. Oveporexton was generally well tolerated in studies; the most common adverse events reported were insomnia, urinary urgency, urinary frequency and excessive saliva.

Disease context

NT1 is a chronic, rare neurological disorder driven by orexin deficiency and characterised by excessive daytime sleepiness, cataplexy, disrupted nighttime sleep, sleep paralysis, hallucinations and cognitive symptoms. The press release notes that diagnostic delay can exceed 10 years due to limited awareness and symptom complexity.