Takeda Pharmaceutical Announces New Pivotal Study Data Showing Oveporexton Improves Daily Functioning, Cognition, and Nocturnal Sleep in Patients with Type 1 Narcolepsy

• Phase 3 secondary and exploratory endpoint results presented at the 40th Annual Meeting of the Associated Professional Sleep Societies (SLEEP 2026) showed that Oveporexton improved a broad range of daytime and nighttime symptoms.
• Takeda is on track to advance global regulatory submissions, aiming to bring the first and only orexin agonist^[6] to patients with narcolepsy type 1.

Osaka, Japan and Cambridge, MassachusettsJune 16, 2026 /PRNewswire/ — Takeda (TSE: 4502/NYSE: TAK) on June 15 announced new results from two pivotal studies at the 40th Annual Meeting of the Associated Professional Sleep Societies (SLEEP 2026). The results showed that the investigational oral selective orexin type 2 receptor (OX2R) agonist Oveporexton (TAK-861) improved daily functioning and disease-related cognitive and sleep symptoms in patients with narcolepsy type 1 (NT1). Oveporexton is designed to target the underlying orexin deficiency that causes NT1 by restoring orexin signaling.^[1,2,3] These data, combined with previously announced Phase 3 results, demonstrate improvements across a broad spectrum of disease symptoms, further supporting its potential to reshape the treatment standard for narcolepsy type 1.^[4]

• Functional Performance: In all dose groups, compared to placebo, Oveporexton showed statistically significant improvements across six dimensions of the Functional Impact of Narcolepsy (FINI) scale at Week 12 (p<0.001). Most patients in each dose group achieved scores at or above published normal reference thresholds, reflecting Oveporexton’s ability to help patients manage daily life activities^[5]. The FINI covers dimensions most impacted by NT1, including fatigue, cognitive function, cataplexy, social activities, daily activities, and daily responsibilities.
• Cognition: Compared to placebo, Oveporexton improved cognitive symptoms associated with NT1, as assessed by objective neuropsychological tests (including attention, executive function, and memory) and patient-reported measures. In the FINI cognitive function dimension, approximately 70% of patients in all dose groups reported no significant cognitive difficulties, compared to about 15% in the placebo group.
• Nighttime Sleep: Exploratory endpoint results showed that Oveporexton improved sleep quality in both studies. In all dose groups, most patients did not report hallucinations or sleep paralysis; among these, in the 2/2 mg dose group, the majority of patients achieved clinically meaningful improvements from baseline in nighttime sleep disturbances. Additionally, the timing and pattern of rapid eye movement (REM) sleep approached that of healthy controls.

“Narcolepsy type 1 is not defined by a single symptom, which is why we designed this comprehensive Phase 3 clinical development program to systematically evaluate Oveporexton’s impact on the broad effects of the disease,” said Sarah Sheikh (M.Sc., B.M., B.Ch., MRCP), Head of Neuroscience Therapeutic Area and Development at Takeda R&D. “We are deeply grateful to all the patients, caregivers, and healthcare professionals who have journeyed with us. Oveporexton is currently under review by multiple regulatory agencies, and we are at a critical juncture in bringing the first and only orexin agonist^[6] to patients with narcolepsy type 1. If approved, it has the potential to reshape the treatment standard for this disease.”

Takeda will present additional data at this conference, including a pooled analysis of previously announced Phase 3 results, data evaluating Oveporexton’s effect on reducing microsleep impacts, and an assessment of the overall symptom burden of NT1 in the United States.

About Oveporexton (TAK-861)

Oveporexton (TAK-861) is an investigational selective orexin type 2 receptor (OX2R) agonist that selectively stimulates OX2R to restore its signaling and improve symptoms caused by orexin deficiency in narcolepsy type 1 (NT1). By activating OX2R, Oveporexton promotes wakefulness and reduces abnormal rapid eye movement (REM) sleep phenomena, including cataplexy, addressing a wide range of daytime and nighttime symptoms.^[7,8] The U.S. Food and Drug Administration (FDA) has accepted Oveporexton’s New Drug Application (NDA) and granted Priority Review, with a current Prescription Drug User Fee Act (PDUFA) target action date in the third quarter of this calendar year. Marketing applications for Oveporexton are also under review in China and Japan, with submissions in other regions expected to proceed later this year. Oveporexton is an investigational compound and has not been approved by any regulatory authority for clinical use.

About the FirstLight and RadiantLight Phase 3 Orexin Studies

FirstLight (TAK-861-3001; NCT06470828) and RadiantLight (TAK-861-3002; NCT06505031) are global, multicenter, placebo-controlled studies^[9] designed to evaluate the efficacy, safety, and tolerability of Oveporexton compared to placebo in patients with narcolepsy type 1 (NT1) over 12 weeks. These studies were conducted in 19 countries, with enrollment completed within 6 months. The FirstLight study enrolled 168 subjects, randomized to one of three dose groups (2 mg twice daily, 1 mg twice daily, and placebo). The RadiantLight study enrolled 105 subjects, randomized to one of two dose groups (2 mg twice daily and placebo). Over 95% of subjects who completed the studies have entered ongoing long-term extension (LTE) studies.

About Takeda

Takeda is committed to “creating better health for people and a brighter future for the world.” We focus on key therapeutic areas including gastroenterology and inflammation, rare diseases, plasma-derived therapies, oncology, neuroscience, and vaccines, striving to develop and deliver breakthrough innovative therapies to patients. Our goal is to partner with others to build a dynamic and diverse pipeline, continuously improve patient experiences, and expand exploration of cutting-edge treatment options. Headquartered in Japan, Takeda is a values-based, R&D-driven global biopharmaceutical company dedicated to fulfilling its commitments to patients, employees, and the planet. Our employees across more than 80 countries and regions share the same mission, upholding values forged over more than two centuries.

For more information, please visit: https://www.takeda.com.

Approval Number: C-ANPROM/CN/TAK-861/0027
Approval Date: June 2026

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1. This material is intended solely to introduce the company’s business and operational activities, and is not intended to promote any company product and/or service, nor should it be construed as providing any advice or recommendations regarding the selection of any drug, medical device, or treatment plan.
2. For information regarding any company product, disease, and/or diagnosis or treatment, please consult a healthcare professional.
3. Oveporexton (TAK-861) mentioned in this article is not yet approved in China.

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