NCT05667142 · Xenon Pharmaceuticals Inc.
A Study to Evaluate XEN1101 as Adjunctive Therapy in Primary Generalized Tonic-Clonic Seizures
(X-ACKT)
What this study is about
This is a Phase 3, conducted at multiple hospitals, randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment study to evaluate the clinical effectiveness, safety, and tolerability of XEN1101 administered as adjunctive treatment in primary generalized tonic-clonic seizures (PGTCS).
View original scientific 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 primary generalized tonic-clonic seizures (PGTCS).
Interventions
DRUG
XEN1101
XEN1101 capsules
DRUG
Placebo
Placebo capsules
Primary outcome measures
Median percent change (MPC) in monthly (28 days) PGTCS frequency
Time frame: Baseline through DBP (Week 12)
Median percent change (MPC) in monthly (28 days) PGTCS frequency from baseline through the DBP for XEN1101 versus placebo.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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 through
Where
- Mobile, Alabama
- Phoenix, Arizona
- Tucson, Arizona
- Little Rock, Arkansas
- Los Angeles, California
- Orange, California
- Sacramento, California
- Aurora, Colorado
- Jacksonville, Florida
- Miami, Florida
- Orlando, Florida
- Pensacola, Florida
And 41 more locations — see the full list below.
Collaborators
Worldwide Clinical Trials
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 8, 2026 · Source of record for eligibility and locations