Recruiting
Phase 3

XEN1101

Sponsor:

Xenon Pharmaceuticals Inc.

Code:

NCT05716100

Conditions

Focal Onset Seizures

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

XEN1101

Placebo

Study Details

Brief summary:

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.

Conditions

Focal Onset Seizures

Study ID

NCT05716100

Start date

May 9, 2023

Status verified date

May, 2026

Completion date

Dec, 2026

Anticipated

Primary completion date

Oct, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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.

Study Design

Enrollment

360 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: XEN1101 25 mg/day

XEN1101 25 mg/day

experimental: XEN1101 15 mg/day

XEN1101 15 mg/day

placebo comparator: Placebo

Placebo

Interventions

XEN1101

XEN1101 Capsules

Placebo

Placebo Capsules

Primary outcome measure

  • Median percent change (MPC) in focal seizure frequency from baseline to DBP for XEN1101 versus placebo. [ Time Frame: From baseline through to the double blind period (week 12). ]

Central Contacts and Locations

Central contacts

Xenon Medical Affairs

1-604-484-3300XenonCares@xenon-pharma.com

Locations

Clinical Trials, Inc.

Recruiting

Little Rock, Arkansas, United States, 72205

Rancho Research Institute

Recruiting

Downey, California, United States, 90242

University of California Los Angeles (UCLA)

Recruiting

Los Angeles, California, United States, 90095

University of California Irvine Health

Recruiting

Orange, California, United States, 92868

Panhandle Research and Medical Clinic

Recruiting

Gulf Breeze, Florida, United States, 32651

Mayo Clinic Florida

Recruiting

Jacksonville, Florida, United States, 32224

Consultants in Epilepsy and Neurology, PLLC

Recruiting

Boise, Idaho, United States, 83702

Southern Illinois University School of Medicine

Recruiting

Springfield, Illinois, United States, 62794

Mid-Atlantic Epilepsy and Sleep Center

Recruiting

Bethesda, Maryland, United States, 20817

9D University Health Center

Recruiting

Detroit, Michigan, United States, 48201

Northeast Regional Epilepsy Group

Recruiting

Hackensack, New Jersey, United States, 07601

Duke University Clinic

Recruiting

Durham, North Carolina, United States, 27705

Cleveland Clinic

Recruiting

Cleveland, Ohio, United States, 44195

OhioHealth

Recruiting

Columbus, Ohio, United States, 43214

Providence Neurological Specialities

Recruiting

Portland, Oregon, United States, 97225

Vanderbilt University Medical Center

Recruiting

Nashville, Tennessee, United States, 37232

Austin Epilepsy Care Center

Recruiting

Austin, Texas, United States, 78758

More Information

Sponsor

Xenon Pharmaceuticals Inc.

Last update posted

May 14, 2026

Last verified

May, 2026

Keywords

  • Epilepsy

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Xenon Pharmaceuticals Inc. on 2026-05-14.