A Randomized Study of XEN1101 Versus Placebo in Focal-Onset Seizures (X-TOLE3)

NCT ID: NCT05716100

Last Updated: 2025-12-19

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

360 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-05-09

Study Completion Date

2026-12-31

Brief Summary

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The X-TOLE3 Phase 3 clinical trial is a randomized, double-blind, placebo-controlled study that will evaluate the clinical efficacy, safety and tolerability of XEN1101 administered as adjunctive therapy in focal-onset seizures.

Detailed Description

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Approximately 360 subjects will be randomized in a blinded manner to one of two active treatment groups or placebo in a 1:1:1 fashion (XEN1101 25 mg : 15 mg : Placebo). Eligible subjects will have up to 9.5 weeks of baseline to assess frequency of seizures, followed by 12 weeks of blinded treatment. In order to be included in the study, subjects must be treated with a stable dose of 1 to 3 allowable antiseizure medications (ASMs) for at least one month prior to screening, during baseline, and throughout the double-blind treatment period (DBP) of the study. During the DBP, subjects will be instructed to orally take XEN1101 or placebo once daily with an evening meal.

Subjects who complete the 12-week DBP will have the opportunity to qualify and enroll in a separate open-label extension (OLE) study for continued treatment with XEN1101. Subjects who do not enroll in the OLE will enter a 8-week post treatment follow-up period.

Conditions

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Focal Onset Seizures

Keywords

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Epilepsy

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Participants Investigators

Study Groups

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XEN1101 25 mg/day

XEN1101 25 mg/day

Group Type EXPERIMENTAL

XEN1101

Intervention Type DRUG

XEN1101 Capsules

XEN1101 15 mg/day

XEN1101 15 mg/day

Group Type EXPERIMENTAL

XEN1101

Intervention Type DRUG

XEN1101 Capsules

Placebo

Placebo

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type DRUG

Placebo Capsules

Interventions

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XEN1101

XEN1101 Capsules

Intervention Type DRUG

Placebo

Placebo Capsules

Intervention Type DRUG

Other Intervention Names

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Azetukalner

Eligibility Criteria

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Inclusion Criteria

* Be properly informed of the nature and risks of the study and give informed consent in writing, prior to entering the study
* Diagnosis (≥2 years) of focal epilepsy according to the International League Against Epilepsy (ILAE) Classification of Epilepsy (2017). Subject must have had adequate trials of at least 2 ASMs, which were given (and tolerated) at adequate therapeutic doses, without achieving sustained seizure freedom.
* Treatment with a stable dose of 1 to 3 allowable current ASMs for at least one month prior to screening, during baseline, and throughout the duration of the DBP
* Able to keep accurate seizure diaries

Exclusion Criteria

* Previously documented electroencephalogram which shows any pattern not consistent with focal etiology of seizures.
* History of focal aware non-motor seizures only, non-epileptic psychogenic seizure, primary generalized seizure, developmental and epileptic encephalopathy, including Lennox-Gastaut syndrome.
* Seizures secondary to drug or alcohol use, ongoing infection, neoplasia, demyelinating disease, degenerative neurological disease, metabolic illness, progressive structural lesion, encephalopathy, or progressive central nervous system (CNS) disease.
* History of status epilepticus or repetitive seizures within the 12-month period preceding Visit 1 where the individual seizures cannot be counted.
* History of neurosurgery for seizures \<1 year prior to Visit 1, or radiosurgery \<2 years prior to enrollment.
* Any medical condition or personal circumstance that, in the opinion of the investigator, exposes the subject to unacceptable risk by participating in the study or prevents adherence to the protocol.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Worldwide Clinical Trials

OTHER

Sponsor Role collaborator

Xenon Pharmaceuticals Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Xenon Medical Director

Role: STUDY_DIRECTOR

Xenon Pharmaceuticals Inc.

Locations

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Rancho Research Institute

Downey, California, United States

Site Status RECRUITING

University of California Los Angeles (UCLA)

Los Angeles, California, United States

Site Status RECRUITING

University of California Irvine Health

Orange, California, United States

Site Status RECRUITING

Panhandle Research and Medical Clinic

Gulf Breeze, Florida, United States

Site Status RECRUITING

Mayo Clinic Florida

Jacksonville, Florida, United States

Site Status RECRUITING

Consultants in Epilepsy and Neurology, PLLC

Boise, Idaho, United States

Site Status RECRUITING

Southern Illinois University School of Medicine

Springfield, Illinois, United States

Site Status RECRUITING

Mid-Atlantic Epilepsy and Sleep Center

Bethesda, Maryland, United States

Site Status RECRUITING

9D University Health Center

Detroit, Michigan, United States

Site Status RECRUITING

Northeast Regional Epilepsy Group

Hackensack, New Jersey, United States

Site Status RECRUITING

Five Towns Neuroscience Research

Woodmere, New York, United States

Site Status WITHDRAWN

Duke University Clinic

Durham, North Carolina, United States

Site Status RECRUITING

Cleveland Clinic

Cleveland, Ohio, United States

Site Status RECRUITING

OhioHealth

Columbus, Ohio, United States

Site Status RECRUITING

Vanderbilt University Medical Center

Nashville, Tennessee, United States

Site Status RECRUITING

University of Utah Clinical Neurosciences Center

Salt Lake City, Utah, United States

Site Status RECRUITING

Hospital Ramos Mejia

Buenos Aires, , Argentina

Site Status RECRUITING

Hospital De Alta Complejidad en Red el Cruce

Buenos Aires, , Argentina

Site Status RECRUITING

Policlinico Lomas

Buenos Aires, , Argentina

Site Status RECRUITING

Instituto de Neurologia Cognitiva (INECO)

Buenos Aires, , Argentina

Site Status RECRUITING

Hospital Italiano

Buenos Aires, , Argentina

Site Status RECRUITING

Hospital Britanico de Buenos Aires

Buenos Aires, , Argentina

Site Status RECRUITING

STAT Resarch S.A.

Buenos Aires, , Argentina

Site Status RECRUITING

CENyR Centro de Especialidades Neurologicas y Rehabilitacion

C.a.b.a., , Argentina

Site Status RECRUITING

FLENI

C.a.b.a., , Argentina

Site Status RECRUITING

Hospital Córdoba

Córdoba, , Argentina

Site Status RECRUITING

Sanatori del Sur S.A.

San Miguel de Tucumán, , Argentina

Site Status RECRUITING

Westmead Hospital

Westmead, New South Wales, Australia

Site Status RECRUITING

Alfred Hospital

Melbourne, Victoria, Australia

Site Status RECRUITING

Austin Health

Melbourne, Victoria, Australia

Site Status RECRUITING

University Hospital Innsbruck

Innsbruck, , Austria

Site Status RECRUITING

Universitätsklinik für Neurologie

Salzburg, , Austria

Site Status RECRUITING

Medical University of Vienna

Vienna, , Austria

Site Status RECRUITING

Cliniques Universitaires Saint-Luc (UCL)

Brussels, , Belgium

Site Status RECRUITING

Universitair Ziekenhuis Gent

Ghent, , Belgium

Site Status RECRUITING

MHATNPsy Sveti Naum EAD

Sofia, , Bulgaria

Site Status RECRUITING

Medical center OPHTHA-NEURO

Sofia, , Bulgaria

Site Status RECRUITING

Clinica Universidad de Los Andes

Santiago, , Chile

Site Status WITHDRAWN

Centro de Investigacion Clinica UC

Santiago, , Chile

Site Status RECRUITING

CINSAN

Santiago, , Chile

Site Status WITHDRAWN

Hospital Clínico Viña del Mar

Viña del Mar, , Chile

Site Status RECRUITING

University Hospital Center Osijek

Osijek, , Croatia

Site Status WITHDRAWN

Clinical Hospital Center Rijeka, Klinika za Neurologiju

Rijeka, , Croatia

Site Status WITHDRAWN

Poliklinika Bonifarm

Zagreb, , Croatia

Site Status RECRUITING

University Hospital Center Zagreb

Zagreb, , Croatia

Site Status RECRUITING

Poliklinika LF MEDICAL

Zagreb, , Croatia

Site Status RECRUITING

EUC Hradec Kralove Clinic

Hradec Králové, , Czechia

Site Status WITHDRAWN

Nemocnicni lekarna FN Motol / Motol University Hospital

Prague, , Czechia

Site Status RECRUITING

Forbeli s.r.o.

Prague, , Czechia

Site Status RECRUITING

Kuopio University Hospital

Kuopio, , Finland

Site Status RECRUITING

Hopital Neurologique Pierre Wertheimer

Bron, , France

Site Status RECRUITING

Centre Hospitalier Universitaire de Lille (CHU de Lille)

Lille, , France

Site Status RECRUITING

Hôpital de la Pitié Salpêtrière

Paris, , France

Site Status RECRUITING

Hôpital Fondation A. de Rothschild

Paris, , France

Site Status RECRUITING

Chu de Rennes Hôpital Pontchaillou

Rennes, , France

Site Status RECRUITING

Hôpital de Hautepierre

Strasbourg, , France

Site Status RECRUITING

Universitätsklinikum Aachen

Aachen, , Germany

Site Status RECRUITING

Krankenhaus Mara gGmbH

Bielefeld, , Germany

Site Status RECRUITING

University Hospital Frankfurt, ZNN - Epilepsy Center Frankfurt Rhine-Main

Frankfurt, , Germany

Site Status RECRUITING

Semmelweis Egyetem, Idegsebészeti és Neurointervenciós Klinika

Budapest, , Hungary

Site Status RECRUITING

Hadassah Medical Center

Jerusalem, , Israel

Site Status RECRUITING

The Chaim Sheba Medical Center

Ramat Gan, , Israel

Site Status RECRUITING

Kaplan Medical Center

Rehovot, , Israel

Site Status RECRUITING

The Tel Aviv Sourasky Medical Center

Tel Aviv, , Israel

Site Status RECRUITING

Ospedali Riuniti di Ancona

Ancona, , Italy

Site Status WITHDRAWN

Università degli studi di Bari Aldo Moro

Bari, , Italy

Site Status RECRUITING

Grupo Medico Camino

Benito Juárez, , Mexico

Site Status RECRUITING

Human Science Research Trials

Mexico City, , Mexico

Site Status RECRUITING

Axis Heilsa S. de R.L. de C.V. Althian

Monterrey, , Mexico

Site Status RECRUITING

Neurocencias Esudios Clinicos S.C.

Sinaloa, , Mexico

Site Status RECRUITING

Kempenhaeghe

Heeze, , Netherlands

Site Status RECRUITING

COPERNICUS Podmiot Leczniczy

Gdansk, , Poland

Site Status RECRUITING

NZOZ Neuromed M. i M. Nastaj Sp. P.

Lublin, , Poland

Site Status WITHDRAWN

Twoja Przychodnia Nowosolskie Centrum Medyczne

Nowa Sól, , Poland

Site Status RECRUITING

MTZ Clinical Research Powered by Pratia

Warsaw, , Poland

Site Status RECRUITING

Centro Hospitalar Universitário de Coimbra - CHUC

Coimbra, , Portugal

Site Status RECRUITING

Hospital da Senhora da Oliveira

Guimarães, , Portugal

Site Status RECRUITING

Centro Hospitalar de Lisboa Norte

Lisbon, , Portugal

Site Status RECRUITING

Centro Hospitalar Lisboa Ocidental

Lisbon, , Portugal

Site Status RECRUITING

Centro Hospitalar Universitário de Santo António

Porto, , Portugal

Site Status RECRUITING

Hospital Pedro Hispano

Porto, , Portugal

Site Status RECRUITING

Centro Hospitalar de Entre o Douro e Vouga

Santa Maria da Feira, , Portugal

Site Status RECRUITING

ULS de Trás-os-Montes e Alto Douro

Vila Real, , Portugal

Site Status RECRUITING

Hospital Universitario Cruces

Barakaldo, , Spain

Site Status RECRUITING

Hospital Unversitario Ramon y Cajal

Madrid, , Spain

Site Status RECRUITING

Hospital universitario Fundación Jiménez Díaz

Madrid, , Spain

Site Status RECRUITING

Countries

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United States Argentina Australia Austria Belgium Bulgaria Chile Croatia Czechia Finland France Germany Hungary Israel Italy Mexico Netherlands Poland Portugal Spain

Central Contacts

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Xenon Medical Affairs

Role: CONTACT

Phone: 1-604-484-3300

Email: [email protected]

Other Identifiers

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XPF-010-302

Identifier Type: -

Identifier Source: org_study_id

2022-502281-25-00

Identifier Type: CTIS

Identifier Source: secondary_id