FDA Grants Priority Review to First Orexin Agonist for Narcolepsy Type 1
Takeda’s oveporexton (TAK-861), an oral orexin receptor 2-selective agonist for narcolepsy type 1, received FDA priority review on February 10, 2026, with a decision expected in the third quarter of 2026.
The Story at a Glance:
- The FDA accepted Takeda’s NDA for oveporexton, a first-in-class oral orexin agonist for narcolepsy type 1, and granted priority review with a PDUFA date in Q3 2026.
- Two Phase 3 trials (FirstLight, n=168; RadiantLight, n=105) met all primary and secondary endpoints at week 12, with p<0.001 across all doses.
- Approximately 85% of participants on the 2 mg twice-daily dose achieved Epworth Sleepiness Scale scores comparable to healthy individuals.
- Oveporexton targets the underlying orexin deficiency that causes narcolepsy type 1 — a mechanism distinct from all currently approved treatments.
What Happened
On February 10, 2026, the FDA accepted Takeda’s New Drug Application for oveporexton (TAK-861) and granted priority review for the treatment of narcolepsy type 1. The orexin agonist for narcolepsy type 1 would be the first approved therapy in this drug class if it clears the regulatory process, with a PDUFA target action date set for the third quarter of 2026, according to Takeda.
Oveporexton is an oral orexin receptor 2 (OX2R)-selective agonist designed to restore the orexin signaling that is lost in narcolepsy type 1. The drug previously received Breakthrough Therapy designation from the FDA for excessive daytime sleepiness in this condition. The NDA is supported by results from two pivotal Phase 3 trials — FirstLight and RadiantLight — both of which met all primary and secondary endpoints.
Unlike existing treatments such as modafinil (Provigil) or sodium oxybate (Xyrem), which manage symptoms without addressing the root cause, oveporexton directly targets the orexin deficiency that defines the disease. Narcolepsy type 1 results from the destruction of hypothalamic orexin-producing neurons, leading to severely reduced brain orexin levels.
Why This Orexin Agonist for Narcolepsy Type 1 Matters
Current narcolepsy type 1 treatments — stimulants, antidepressants, and sodium oxybate — offer symptomatic relief but leave many patients with persistent sleepiness, cataplexy, and impaired quality of life. No approved therapy directly replaces the missing orexin signal. Oveporexton’s mechanism of action would represent the first disease-targeted approach in this condition.
Key Details
| Drug | Oveporexton (TAK-861) |
|---|---|
| Manufacturer | Takeda Pharmaceuticals |
| Drug Class | Oral orexin receptor 2 (OX2R)-selective agonist |
| Indication | Narcolepsy type 1 (NT1) |
| Dose / Route | 1 mg or 2 mg twice daily, oral |
| Regulatory Pathway | Priority Review; Breakthrough Therapy designation |
| NDA Accepted | February 10, 2026 |
| PDUFA Date | Q3 2026 |
| Pivotal Trials | FirstLight (n=168) and RadiantLight (n=105); 19 countries; 12-week, randomized, double-blind, placebo-controlled |
| Primary Endpoint | Change in Maintenance of Wakefulness Test (MWT) sleep latency at week 12 |
| Key Secondary Endpoints | Epworth Sleepiness Scale (ESS) score; Weekly Cataplexy Rate (WCR) |
| Phase 2b Publication | NEJM, May 2025 (DOI: 10.1056/NEJMoa2405847) |
In the Phase 2b trial published in the New England Journal of Medicine, 112 adults with narcolepsy type 1 were randomized to four dosing arms or placebo over 8 weeks. The 2 mg twice-daily group showed a mean MWT improvement of 23.5 minutes compared to a 1.2-minute decline with placebo (adjusted p≤0.001). ESS scores dropped by 13.8 points versus 2.5 with placebo (adjusted p≤0.004). No hepatotoxicity or visual disturbances were reported.
What Experts Are Saying
“The loss of orexin is the cause of narcolepsy type 1.”
— Emmanuel Mignot, MD, PhD, Craig Reynolds Professor of Sleep Medicine, Stanford University; FirstLight principal investigator
Mignot described the positive Phase 3 results as bringing clinicians closer to having a therapy that targets the underlying cause of the disease, rather than managing symptoms alone. Andy Plump, MD, PhD, president of R&D at Takeda, stated that the FDA acceptance represented a milestone for patients who need new treatment options that address the underlying orexin deficiency.
What’s Next
The FDA is expected to issue its decision on the oveporexton NDA in the third quarter of 2026. Takeda has also filed for regulatory approval with other global authorities. More than 95% of Phase 3 participants enrolled in an ongoing long-term extension study, which will provide additional safety and durability data.
Takeda is simultaneously developing TAK-360, a separate oral OX2R agonist currently in Phase 2 trials for narcolepsy type 2 and idiopathic hypersomnia. Other companies are earlier in development: Eisai presented Phase 1b data for E2086 at World Sleep 2025, and Centessa Pharmaceuticals is advancing ORX750 in early-stage trials.
The Bigger Picture
The development of orexin agonists for narcolepsy type 1 reflects a broader shift in sleep medicine toward mechanism-based therapies. While orexin receptor antagonists such as suvorexant (Belsomra) and lemborexant (Dayvigo) are already approved to treat insomnia by blocking orexin-driven wakefulness, agonists that restore orexin signaling represent the other side of this biology. If oveporexton is approved, it could also accelerate diagnostic efforts in a condition that remains widely underdiagnosed, with many patients waiting years between symptom onset and a confirmed diagnosis.
Bottom Line
- Oveporexton is the first orexin agonist for narcolepsy type 1 to receive FDA priority review, with a decision expected in Q3 2026.
- Phase 3 data showed improvements in wakefulness and cataplexy that brought most participants into ranges seen in healthy individuals.
- If approved, this would mark the first narcolepsy type 1 treatment to target the underlying orexin deficiency.
- Long-term safety, real-world durability, and effects on disease progression beyond 12 weeks remain to be established.
Sources
- Takeda Pharmaceuticals. U.S. Food and Drug Administration Accepts New Drug Application and Grants Priority Review for Takeda’s Oveporexton (TAK-861). Press release. February 10, 2026. Link
- Dauvilliers Y, Plazzi G, Mignot E, et al. Oveporexton, an Oral Orexin Receptor 2–Selective Agonist, in Narcolepsy Type 1. N Engl J Med. 2025;392(19):1905-1916. DOI: 10.1056/NEJMoa2405847
- Takeda Pharmaceuticals. Takeda Announces Positive Results from Two Pivotal Phase 3 Studies of Oveporexton (TAK-861) in Narcolepsy Type 1. Press release. July 14, 2025. Link
- Takeda Pharmaceuticals. Takeda Presents Orexin Data from Landmark Oveporexton (TAK-861) Phase 3 Program at World Sleep 2025. Press release. September 8, 2025. Link
- ClinicalTrials.gov. A Study to Evaluate TAK-861 in Adult Participants With Narcolepsy Type 1 (FirstLight). NCT06470828
- ClinicalTrials.gov. A Study of TAK-861 in People With Narcolepsy Type 1 (RadiantLight). NCT06505031