Cenobamate Open-Label Extension Study for YKP3089C025

Study Overview
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Brief Summary
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52 Week Open-Label Safety Study of Cenobamate for Subjects who Complete YKP3089C025 (core study)

Detailed Description
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52 Week Open-Label Safety Study of cenobamate adjunctive therapy for subjects who complete double-blind study YKP3089C025. Subjects will have a 12 week double-blind conversion phase where subjects who received placebo in the double-blind study will be converted to cenobamate. Subjects who received cenobamate in the double-blind study will continue to receive their daily dose of cenobamate. Subjects switching from placebo to cenobamate will be titrated starting at 12.5 mg and increase their dose over the course of 12 weeks as follows 12.5 mg for 2 weeks, 25 mg for two weeks, 50 mg for two weeks, 100 mg for two weeks, 150 mg for two weeks, and 200 mg for two weeks. All subjects will receive 200 mg for the last two weeks of the conversion phase to preserve the blind. After completing the double-blind conversion phase, subjects will have 40 weeks of open-label, flexibly dosed cenobamate. The dose range is 50 mg - 200 mg. Primary endpoints are all safety measures. The adolescent subjects will follow the same regimen in an oral suspension adolescent equivalent dose based on weight.

Official Title
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A Multicenter Open-Label Extension Study to Evaluate the Long-Term Safety of Cenobamate Adjunctive Therapy in Subjects With Primary Generalized Tonic-Clonic Seizures

Conditions
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Primary Generalized Tonic Clonic Seizures in the Setting of Idiopathic Generalized Epilepsy

Intervention / Treatment
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* Drug: Cenobamate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The subject must have successfully completed the Double-blind Treatment Period in the Core study. Written informed consent signed by the subject or legal guardian, prior to entering the study, in accordance with the International Council for Harmonisation (ICH) Good Clinical Practice (GCP) guidelines. If the written informed consent is provided by the legal guardian because the subject is unable to do so, a written or verbal assent from the subject must also be obtained. As required by country-specific regulations, only the subject may sign the ICF in accordance with ICH guidelines. Exclusion Criteria: Subject tests positive, via urine drug screen at Visit 14 of the Core study, for illicit drugs except for tetrahydrocannabinol and Cannabinoids. Any significant changes to the subject's medical history that, in the opinion of the Principal Investigator, could affect the subject's safety or conduct of the study.

Ages Eligible for Study
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Minimum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Core Study Placebo<br>Subjects who did not receive Cenobamate in the Core Study will receive Cenobamate 12.5 mg tablet once a day for two weeks, 25 mg tablet once a day for two weeks, 50 mg tablet once a day for two weeks, 100 mg tablets once a day for two weeks, 150 mg tablets once a day for two weeks and 200 mg tablets once a day for twelve weeks. The adolescent subjects will follow the same regimen in an oral suspension adolescent equivalent dose based on weight. | Drug: Cenobamate<br>* active drug<br>* Other names: YKP3089;|
| Experimental: Core Study Active<br>Subjects who received cenobamate in the Core study will continue to receive the same daily dose (150 mg or 200mg). The adolescent subjects will follow the same regimen in an oral suspension adolescent equivalent dose based on weight. | Drug: Cenobamate<br>* active drug<br>* Other names: YKP3089;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of Adverse Events and SAEs | Summary statistics for clinical laboratory test results and vital signs; and physical examination, neurologic examination and electrocardiogram (ECG) finding. | 386 +/- 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Idiopathic Generalized Epilepsy