Small Molecule · TAK-861

Oveporexton

  • Breakthrough Therapy
  • Priority Review

Oveporexton (TAK-861) is an oral, highly selective orexin receptor 2 (OX2R/HCRTR2) agonist developed by Takeda to address the underlying orexin (hypocretin) deficiency that causes narcolepsy type 1. By selectively activating OX2R on wake-promoting neurons, it enhances wakefulness and suppresses abnormal REM-sleep events such as cataplexy. It is the lead asset in Takeda's orexin franchise and is in late-stage development for NT1.

Also known as: TAK-861, Oveporexton, 2460722-04-5

Modality
Small molecule
Chemical class
pyrrolidine, ethanesulfonamide
Chemistry
Single enantiomer
Mechanism
OX2R agonist
Highest phase
Filed (NDA)
Lead indication
Narcolepsy
Designations
Breakthrough Therapy, Priority Review
Trials
3 tracked

Mechanism of action

Oveporexton is a potent, orally available, highly selective orexin receptor 2 (OX2R/HCRTR2) agonist with minimal activity at OX1R. By selectively activating OX2R on wake-promoting hypothalamic and brainstem neurons, it restores deficient orexin signaling in narcolepsy type 1, enhancing downstream monoaminergic and cholinergic wake-promoting pathways to increase wakefulness and suppress abnormal REM-sleep events such as cataplexy.

TargetActionAffinity
OX2RprimaryHCRTR2Agonist

Formulations

FormulationRouteRegimenPharmacokinetics
Oveporexton oral tablet
1 mg or 2 mg twice daily (Phase 3 FirstLight/RadiantLight); Phase 2 also tested 7 mg once daily
OralTwice daily

Development timeline

Filed (NDA)Feb 2026
  1. FDA accepted the oveporexton NDA for narcolepsy type 1 and granted Priority Review, with a PDUFA target action date in Q3 2026.
Phase 3Jul 2025
  1. metPhase 3 FirstLight and RadiantLight pivotal studies met all primary and key secondary endpoints (p<0.001) at week 12.
Phase 2May 2025
  1. metPhase 2b (TAK-861-2001) met primary MWT endpoint and key secondary endpoints (ESS, weekly cataplexy rate); results published in the New England Journal of Medicine.

Oveporexton for Narcolepsy

Filed (NDA)ActiveNarcolepsy indication →

Oveporexton (TAK-861) is in regulatory review for narcolepsy type 1. Following positive Phase 3 FirstLight and RadiantLight pivotal studies, the FDA accepted Takeda's New Drug Application and granted Priority Review on 2026-02-10, with a PDUFA target action date in Q3 2026. The program holds FDA Breakthrough Therapy designation for excessive daytime sleepiness in NT1. NT1 is the lead indication of Takeda's orexin franchise.

Readouts

  • 2026-02-10ReportedRegulatory

    FDA accepted the oveporexton NDA for narcolepsy type 1 and granted Priority Review, with a PDUFA target action date in Q3 2026.

  • 2025-07-14ReportedTopline datametNCT06470828

    Phase 3 FirstLight and RadiantLight pivotal studies met all primary and key secondary endpoints (p<0.001) at week 12.

  • 2025-05-14ReportedFull resultsmetNCT05687903

    Phase 2b (TAK-861-2001) met primary MWT endpoint and key secondary endpoints (ESS, weekly cataplexy rate); results published in the New England Journal of Medicine.

Clinical trials

NCT06505031TAK-861-3002Phase 3Completedn=105

RadiantLight: A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1)

Started Oct 2024· Primary completion Jun 2025

metprimaryExcessive daytime sleepiness via Maintenance of Wakefulness Test (MWT) at week 12 — Clinically meaningful improvement with participants achieving near-normal ranges (<0.001)

Met primary MWT endpoint with statistically significant improvement vs placebo at week 12 (p<0.001). RadiantLight randomized 105 participants to high dose or placebo.

metsecondaryEpworth Sleepiness Scale (ESS) and Weekly Cataplexy Rate (WCR) at week 12 (<0.001)

All key secondary endpoints, including ESS and weekly cataplexy rate, were met with statistically significant improvement vs placebo at week 12 (p<0.001).

NCT06470828TAK-861-3001Phase 3Completedn=168

FirstLight: A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1)

Started Jul 2024· Primary completion Jun 2025

metprimaryExcessive daytime sleepiness via Maintenance of Wakefulness Test (MWT) at week 12 — Clinically meaningful improvement with participants achieving near-normal ranges (<0.001)

Met primary MWT endpoint with statistically significant improvement vs placebo across all doses at week 12 (p<0.001). FirstLight randomized 168 participants to high dose, low dose, or placebo.

metsecondaryEpworth Sleepiness Scale (ESS) and Weekly Cataplexy Rate (WCR) at week 12 (<0.001)

All key secondary endpoints, including ESS and weekly cataplexy rate, were met with statistically significant improvement vs placebo across all doses at week 12 (p<0.001).

NCT05687903TAK-861-2001Phase 2Completedn=112

A Randomized, Double-blind, Placebo-Controlled Study to Evaluate the Efficacy, Safety, and Tolerability of TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1)

Started Jan 2023· Primary completion Dec 2023

metprimaryMean sleep latency on the Maintenance of Wakefulness Test (MWT) — Mean sleep latency reached values consistent with normative ranges in healthy individuals across all active doses (<=0.001)

Substantial, dose-spanning increases in mean MWT sleep latency vs placebo, sustained over 8 weeks (adjusted p <=0.001 for all comparisons).

metsecondaryEpworth Sleepiness Scale (ESS)

Significant reductions in ESS (excessive daytime sleepiness) across all doses vs placebo, sustained over 8 weeks.

metsecondaryWeekly Cataplexy Rate (WCR)

Significant reductions in weekly cataplexy rate across all doses vs placebo, sustained over 8 weeks.

Conference coverage

TAK-861 appears in 1 CNS Pulse conference abstract:

Identifiers

Sources

  1. FirstLight: TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1) - Phase 3 (TAK-861-3001) — ClinicalTrials.gov
  2. NEJM Publication: Significant Improvements for Narcolepsy Type 1 in Phase 2b Trial of Oveporexton (TAK-861) — Takeda Pharmaceutical Company
  3. Oveporexton, an Oral Orexin Receptor 2-Selective Agonist, in Narcolepsy Type 1 (NEJM Phase 2; oral, once- and twice-daily dosing) — New England Journal of Medicine (PubMed)
  4. RadiantLight: TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1) - Phase 3 (TAK-861-3002) — ClinicalTrials.gov
  5. TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1) - Phase 2b (TAK-861-2001) — ClinicalTrials.gov
  6. Takeda Announces Positive Results from Two Pivotal Phase 3 Studies of Oveporexton (TAK-861) in Narcolepsy Type 1 (investigational oral OX2R agonist) — Takeda Pharmaceutical Company
  7. U.S. Food and Drug Administration Accepts New Drug Application and Grants Priority Review for Takeda's Oveporexton (TAK-861) as a Potential First-in-Class Therapy for Narcolepsy Type 1 — Takeda Pharmaceutical Company