FDA Approves First Orexin Agonist for Narcolepsy Type 1

The FDA has approved oveporexton (Orzeyful; Takeda), an oral orexin receptor 2 (OX2R) agonist, for the treatment of narcolepsy type 1 (NT1, narcolepsy with cataplexy) in adults.¹ The agency's decision, announced August 5, 2026, positions oveporexton as the first therapy indicated to address the underlying orexin deficiency that drives NT1, rather than managing its symptoms individually.

First-in-Class Mechanism Targets Orexin Deficiency

NT1 is a rare, chronic neurological disease caused by a loss of orexin-producing neurons, affecting an estimated 120,000 people in the US. The condition produces a persistent, 24-hour symptom burden that includes excessive daytime sleepiness, cataplexy, cognitive symptoms, and disrupted nighttime sleep, with effects that extend into work, education, and social functioning.

Oveporexton selectively stimulates OX2R to restore orexin signaling, promoting wakefulness and reducing abnormal rapid eye movement (REM) sleep phenomena, including cataplexy. Takeda characterizes the approval as the introduction of an entirely new drug class for the field.

“As the first and only approved orexin therapy to treat the broad spectrum of the disease, Orzeyful can enable a different kind of conversation in the doctor’s office about treatment options,” Emmanuel Mignot, MD, PhD, principal US investigator for the Orzeyful phase 3 program, said in a statement.

Phase 3 Program Shows Broad Symptom Improvement

The approval was supported by the global phase 3 FirstLight (TAK-861-3001; NCT06470828) and RadiantLight (TAK-861-3002; NCT06505031) trials, which demonstrated statistically significant improvements across the full symptom range of NT1, including excessive daytime sleepiness, cataplexy, and health-related quality of life, compared with placebo. Oveporexton was generally well tolerated, with a safety profile consistent across the clinical program; the most common adverse effects were insomnia, urinary urgency, urinary frequency, and excessive salivation.

Additional analyses of the FirstLight and RadiantLight data presented at the SLEEP 2026 Annual Meeting in June expanded on these findings.² Polysomnography data from 157 FirstLight and 101 RadiantLight participants showed that oveporexton normalized REM sleep architecture, including longer REM latency, less time spent in REM during the first quarter of the night, and fewer NT1-specific REM transitions, alongside reductions in total REM percentage. A separate cognitive analysis using the Psychomotor Vigilance Test found that 57.6% to 71.9% of oveporexton-treated patients achieved a clinically meaningful improvement in attention by week 12, compared with 17.6% to 25.7% of patients on placebo.

Safety Considerations for Prescribers

Labeling under review includes warnings for insomnia, which developed in up to 60% of oveporexton-treated patients in pooled phase 3 studies versus 1% on placebo, and for urinary frequency and urgency, linked to OX2R agonism on central micturition pathways.¹ Asymptomatic creatine phosphokinase elevations greater than 5 times the upper limit of normal were also observed more often with oveporexton than placebo. Orzeyful is contraindicated with strong CYP3A inhibitors, and its full prescribing information remains subject to change pending DEA scheduling.

Because oveporexton has potential for abuse and misuse, its controlled substance classification is under DEA review, with a decision expected within 90 days of the FDA approval. Once scheduling is finalized, Orzeyful will be distributed through a specialty pharmacy to US health care providers and patients with NT1. Takeda said the approval is not expected to materially affect its consolidated financial forecast for the fiscal year ending March 31, 2027.

Oveporexton is also approved for NT1 in China, and Takeda is developing additional orexin agonists, including TAK-360 for NT1, narcolepsy type 2, and idiopathic hypersomnia, and TAK-495.

References

1. FDA approves Takeda's Orzeyful (oveporexton), the first and only medicine to treat the underlying cause of narcolepsy type 1. News release. Takeda; August 5, 2026. Accessed August 13, 2026. https://www.takeda.com/newsroom/newsreleases/2026/orzeyful-approved-narcolepsy/

2. Bonavitacola J. Oveporexton effective in improving REM sleep, improving cognitive function in narcolepsy. AJMC^®. June 15, 2026. Accessed August 13, 2026. https://www.ajmc.com/view/oveporexton-effective-in-improving-rem-sleep-improving-cognitive-function-in-narcolepsy