A Study to Evaluate XEN1101 as Adjunctive Therapy in Primary Generalized Tonic-Clonic Seizures

Launched by XENON PHARMACEUTICALS INC. · Dec 27, 2022

Keywords

ClinConnect Summary

This clinical trial is studying a medication called XEN1101 to see if it can help reduce the frequency of primary generalized tonic-clonic seizures (PGTCS) in people who are already taking other seizure medications but are still having seizures. This is a Phase 3 trial, which means it is one of the final stages of testing before the drug can be considered for approval. The study is open to anyone aged 12 and older who has had PGTCS for at least a year and has tried at least two other seizure medications without success. Participants will need to keep track of their seizures and will be monitored throughout the study.

If you or someone you know is interested in participating, it's important to know that participants should not have had certain recent seizures or other serious medical issues that could interfere with the study. The trial is currently recruiting participants, and those who join will be randomly assigned to either receive XEN1101 or a placebo (a dummy medication that looks the same but has no active ingredients) to see how well it works. This study aims to provide more information about the safety and effectiveness of XEN1101 for treating PGTCS.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 1. 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:
• • 1. 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 focal-onset seizures (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 central nervous system (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.