OSAKA, Japan & CAMBRIDGE, Massachusetts, Aug 24, 2026
Takeda Pharmaceutical Company Limited announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has approved ORZEYFUL (oveporexton) for the treatment of narcolepsy type 1 (NT1) in adults. The approval marks the first approval of oveporexton in Japan and the third major regulatory approval for the medicine globally. ORZEYFUL is an oral orexin receptor 2 (OX2R) agonist designed to address the underlying orexin deficiency associated with NT1 rather than treating individual symptoms separately. Takeda said it is preparing for launch and expects to make the medicine available in Japan as quickly as possible.
ORZEYFUL Targets Underlying Orexin Deficiency
ORZEYFUL is a first-in-class oral OX2R agonist that selectively stimulates the orexin receptor 2 pathway. Narcolepsy type 1 is a chronic neurological disorder driven by orexin deficiency, with patients experiencing excessive daytime sleepiness, cataplexy, disrupted nighttime sleep, sleep paralysis, hallucinations and cognitive symptoms. Historically, treatment has largely focused on managing individual symptoms, while ORZEYFUL represents a therapeutic approach intended to address the underlying disease biology. By activating OX2Rs, oveporexton is designed to restore orexin signaling, promote wakefulness and reduce abnormal REM-sleep-related phenomena such as cataplexy. The Japanese approval therefore represents an important development in the treatment of NT1 and Takeda’s broader effort to translate its orexin research into new therapeutic options.
Phase 3 Studies Support Japanese Approval
The MHLW decision was supported by Takeda’s comprehensive clinical development program, including the global Phase 3 FirstLight and RadiantLight studies. According to the company, the studies demonstrated statistically significant and meaningful improvements across the range of NT1 symptoms evaluated, including excessive daytime sleepiness, cataplexy and other secondary measures. Oveporexton was generally well tolerated, with a safety profile that remained consistent across clinical studies conducted to date. The most frequently reported adverse events included insomnia, urinary urgency, urinary frequency and excessive saliva. The clinical findings provided the basis for the Japanese regulatory submission and support the medicine’s potential to offer a more comprehensive treatment approach for adults living with NT1.
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Takeda Expands Global Orexin Treatment Strategy
The Japanese approval strengthens Takeda’s global orexin franchise, following approvals of ORZEYFUL in China and the United States. In China, the medicine is approved for adolescents aged 16 years and older and adults with NT1, while the U.S. approval covers adults with NT1. The company is continuing to build its portfolio of investigational orexin agonists for sleep-wake disorders and other conditions in which orexin signaling may play a role, including respiration, mood and metabolism. Takeda is also developing oral candidates such as TAK-360 for NT1, narcolepsy type 2 and idiopathic hypersomnia, as well as TAK-495. In Japan, ORZEYFUL is marketed as oveporexton and is indicated for narcolepsy type 1. The product information states that the usual adult dosage is 1 mg administered orally twice daily, with the first dose taken upon awakening and the second dose three to five hours later. The dose may be increased to 2 mg twice daily when adequately tolerated and when sufficient efficacy is not observed. The approval represents a significant milestone for Takeda’s neuroscience and orexin research, bringing a disease-focused treatment approach to adults with NT1 in Japan. It also demonstrates the progression of a medicine discovered through Takeda’s research laboratories in Japan from scientific discovery through global clinical development and regulatory approval.
Source: Takeda press release
