Tests XEN1101 against placebo for focal-onset seizures
Tests XEN1101 added to usual treatment in adults with focal-onset seizures.
Plain-language title generated from the registry record
Registry title: A Randomized Study of XEN1101 Versus Placebo in Focal-Onset Seizures (X-TOLE3)
Key facts
- Where
- Austin, Bethesda, Boise, Cleveland, Columbus, Detroit, Downey, Durham, Gulf Breeze, Hackensack, Jacksonville, Little Rock, Los Angeles, Nashville, Orange, Portland, Salt Lake City, Springfield, and Woodmere, United StatesSee the 19 sites
- Phase
- Phase 3
Where in United States
- Austin Epilepsy Care CenterAustin, United StatesTaking people
- Mid-Atlantic Epilepsy and Sleep CenterBethesda, United StatesTaking people
- Consultants in Epilepsy and Neurology PLLCBoise, United StatesTaking people
- Cleveland ClinicCleveland, United StatesTaking people
- OhioHealthColumbus, United StatesTaking people
- 9D University Health CenterDetroit, United StatesTaking people
- Rancho Research InstituteDowney, United StatesNo longer taking part
- Duke University ClinicDurham, United StatesTaking people
- Panhandle Research and Medical ClinicGulf Breeze, United StatesTaking people
- Northeast Regional Epilepsy GroupHackensack, United StatesTaking people
- Mayo Clinic FloridaJacksonville, United StatesTaking people
- Clinical Trials Inc.Little Rock, United StatesNo longer taking part
- University of California Los Angeles (UCLA).Los Angeles, United StatesTaking people
- Vanderbilt University Medical CenterNashville, United StatesTaking people
- University of California, Irvine HealthOrange, United StatesTaking people
- Providence Neurological SpecialitiesPortland, United StatesTaking people
- University of Utah Clinical Neurosciences CenterSalt Lake City, United StatesNo longer taking part
- Southern Illinois University School of MedicineSpringfield, United StatesTaking people
- Five Towns Neuroscience ResearchWoodmere, United StatesNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Xenon Pharmaceuticals Inc.
- Trial code
- NCT05716100EU 2022-502281-25-00
- Record updated
- 2 November 2026
- Original description
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.Read full original descriptionShow less
A Randomized, Double-blind, Placebo-Controlled, Multicenter Phase 3 Study to Evaluate the Safety, Tolerability, and Efficacy of XEN1101 as Adjunctive Therapy in Focal-Onset Seizures
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.
Inclusion: 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: Previously documented electroencephalogram which shows any pattern not consistent with focal etiology of seizures; History of neurosurgery for seizures <1 year prior to Visit 1, or radiosurgery <2 years prior to enrollment; 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; 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.