A Study to Evaluate XEN1101 as Adjunctive Therapy in Primary Generalized Tonic-Clonic Seizures
Purpose
This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled study to evaluate the clinical efficacy, safety, and tolerability of XEN1101 administered as adjunctive treatment in primary generalized tonic-clonic seizures (PGTCS).
Condition
- Primary Generalized Tonic-Clonic Seizures
Eligibility
- Eligible Ages
- Over 12 Years
- Eligible Genders
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- Subject is properly informed of the nature and risks of the study and gives informed consent in writing prior to entering the study (for adult subjects) and for adolescent subjects parent/legal guardian and subject gives informed consent or assent in writing prior to entering the study. 2. Subject is ≥12 years of age with a BMI ≤40 kg/m2 at Visit 1. 3. 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. 4. Subject has probable or possible PGTCS (with or without other subtypes of generalized seizures) for ≥1 year, in the setting of generalized epilepsy according to the International League Against Epilepsy 2017 classification criteria, and subject is approved by The Epilepsy Study Consortium (TESC). 5. Subject is on a stable dose of 1 to 3 allowable current ASMs for at least 1 month prior to screening (Visit 1), during screening/baseline, and throughout the DBP. 6. Subject is able to keep accurate seizure diaries.
Exclusion Criteria
- Subject has had status epilepticus within the 12 months prior to Visit 1. 2. Subject has history of repetitive seizures within the 12-month period preceding Visit 1 where the individual seizures cannot be counted. 3. Subject has a history of non-epileptic psychogenic seizures. 4. Subject has a concomitant diagnosis of FOS. 5. Subject has presence or history of a developmental and epileptic encephalopathy, including Lennox-Gastaut syndrome. 6. Subject has seizures secondary to drug or alcohol use, ongoing infection, neoplasia, demyelinating disease, degenerative neurological disease, metabolic illness, progressive structural lesion, encephalopathy, or progressive CNS disease. 7. Subject has history of neurosurgery for seizures <1 year prior to Visit 1, or radiosurgery <2 years prior to Visit 1. 8. Subject has schizophrenia and other psychotic disorders (eg, schizophreniform disorder, schizoaffective disorder, psychosis not otherwise specified), bipolar disorder, obsessive-compulsive disorder, or another serious mental health disorder. Subject has uncontrolled unipolar major depression where changes in pharmacotherapy are needed or anticipated during the study. 9. Subject has any clinically significant laboratory abnormalities or clinically significant abnormalities on prestudy physical examination, vital signs, or ECG that, in the judgment of the investigator, indicate a medical problem that would preclude study participation, including but not limited to: a. History or presence of long QT syndrome; QTcF >450 msec at baseline; family history of sudden death of unknown cause. 10. Any personal circumstance that, in the opinion of the investigator, prevents adherence to the protocol. The criteria to be eligible for randomization are: 1. During the last 56 days of the baseline period that preceded the randomization visit (Visit 2), subject must have had a sufficient documented seizure frequency of PGTCS, including ≥1 PGTCS during each of the first and second 4-week periods preceding randomization. 2. Seizure diary was completed a minimum of 80% of all days (ie, ≥45 days) during the last 56 days of the baseline period that preceded randomization as evidence of adequate compliance. 3. Subject did not change dose of, stop, or initiate any new ASM(s) during the baseline period and plans on maintaining a stable dose of ASM(s) during the DBP.
Study Design
- Phase
- Phase 3
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel Assignment
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Investigator)
Arm Groups
Arm | Description | Assigned Intervention |
---|---|---|
Experimental XEN1101 25 mg/day |
XEN1101 25 mg/day |
|
Placebo Comparator Placebo |
Placebo |
|
Experimental XEN1101 15 mg/day |
XEN1101 15 mg/day |
|
Recruiting Locations
Mobile, Alabama 36604
Phoenix, Arizona 85004
Little Rock, Arkansas 72205
Los Angeles, California 90025
Orange, California 92868
Sacramento, California 95817
Aurora, Colorado 80045
Miami, Florida 33176
Orlando, Florida 32806
Pensacola, Florida 32503
Port Charlotte, Florida 33952
Tampa, Florida 33606
Weston, Florida 33331
Atlanta, Georgia 30329
Suwanee, Georgia 30024
Honolulu, Hawaii 96817
Boise, Idaho 83702
Springfield, Illinois 62794
Indianapolis, Indiana 46202
Kansas City, Kansas 66160
Lexington, Kentucky 40504
Lexington, Kentucky 40536
Baltimore, Maryland 21201
Bethesda, Maryland 20817
Chestnut Hill, Massachusetts 02467
Worcester, Massachusetts 01655
Ann Arbor, Michigan 48109
Detroit, Michigan 48201
East Lansing, Michigan 48824
Grand Rapids, Michigan 49503
Hackensack, New Jersey 07601
Amherst, New York 14226
Syracuse, New York 13201
Woodmere, New York 11598
Winston-Salem, North Carolina 27104
Akron, Ohio 44304
Cleveland, Ohio 44195
Columbus, Ohio 43210
Columbus, Ohio 43214
Philadelphia, Pennsylvania 19104
Philadelphia, Pennsylvania 19140
Charleston, South Carolina 29425
El Paso, Texas 79912
San Antonio, Texas 78229
Salt Lake City, Utah 84132
Virginia Beach, Virginia 23456
Seattle, Washington 98104
Milwaukee, Wisconsin 53215
More Details
- NCT ID
- NCT05667142
- Status
- Recruiting
- Sponsor
- Xenon Pharmaceuticals Inc.
Detailed Description
This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled study to evaluate the clinical efficacy, safety, and tolerability of XEN1101 administered as adjunctive treatment in subjects diagnosed with generalized epilepsy and experiencing probable or possible PGTCS (with or without other subtypes of generalized seizures), and taking 1 to 3 anti-seizure medications (ASMs). Eligible subjects will be randomly assigned 1:1 to XEN1101 or placebo: subjects aged ≥ 18 years will receive XEN1101 25 mg or placebo, and subjects aged ≥12 years and <18 years will receive either XEN1101 15 mg, 25 mg, or placebo. Randomization will be stratified based on region, age group, and background use of CYP3A4-inducer ASMs. Eligible subjects will have up to 9.5 weeks durations to assess the baseline frequency of seizures, followed by a double-blind treatment period (DBP) where subjects will receive 12 weeks of blinded treatment. 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 enroll in a separate open-label-extension (OLE) study for continued treatment with XEN1101. Subjects who do not enroll in the OLE will enter an 8 week post-treatment follow-up period.