Cenobamate Monotherapy Study (YKP3089C049)

Clinical trials are research studies that are conducted on human beings. In general, these studies are conducted to evaluate what the body does to the drug and what the drug does to the body. In these studies, the efficacy (effectiveness) of the drug and safety and tolerability will be evaluated in the specific patient population. The Cenobamate Monotherapy study (YKP3089C049) is evaluating the safety and efficacy of cenobamate in newly diagnosed or recurrent partial-onset epilepsy adult patients. There is NO COST to patients who are participating in this study.

You will be paid a defined stipend amount for the study visits you complete. In addition to that defined amount, your travel expenses to and from the study site may be reimbursed, which should be discussed with the study doctor.

Taking part in this study will not cost you anything. You will not be charged for the study drug or any of the tests that are part of the study.

The research team at the study site nearest you will explain in detail what the study will involve. Participation in this study is voluntary, and you will decide whether you want to participate. Your decision to participate or not participate will have no effect on the medical care you receive now or in the future. If you are eligible for this study and you choose to participate, you can still change your mind afterward without providing any reason.

The study is being conducted across several study sites in the United States. We recommend finding the study site location that is closest to where you live.

A few key facts about this study include:

• Cenobamate is an approved drug in the US, Europe, and several other countries around the world for the treatment of partial-onset seizures in adult subjects. In the US, cenobamate is approved for use as monotherapy. Commercial supply of cenobamate will be used for this study.
• This study is open-label and single-arm, meaning, every participant will receive cenobamate.
• Cenobamate will be given as oral tablets taken by mouth once daily or twice daily if needed.
• Once participants start cenobamate and throughout the rest of the study, cenobamate is the only anti-seizure medication participants can take with a few exceptions.
• The required activities at study visits are minimal and do not include labs, imaging, special tests, etc, unless the study doctor deems necessary.

Screening (up to 21 days):

The first step is to go through the Informed Consent process, during which you will learn about the Cenobamate Monotherapy study from the site staff. The goal of this consent process is to make sure you understand the requirements of the study, the possible risks and benefits of participating in the study, and to give you a chance to ask questions. You will receive an Informed Consent to read that explains the study. Signing the form means you give permission for you to be part of the study. After that, there will be health checks and tests to determine if the participant meets the study requirements.

100 milligram per day Treatment Period (up to 32 weeks):

Participants who meet the study requirements will enter this period which includes 5 study visits and an up-titration to 100 mg/day. During visits, the seizure diary will be collected, the study drug will be given to participants, and health checks will be done.

200 milligram per day Treatment Period (up to 28 weeks):

Participants may enter this period if certain types of seizures are experienced during the 100 milligram per day Treatment Period and will be titrated up from 100 mg/day to 200 mg/day. This period includes 5 study visits. During visits, the seizure diary will be collected, the study drug will be given to participants, and health checks will be done.

Optional Extension Period (up to 26 weeks):

Participants can choose to enter this period after successful completion of the Treatment Period(s). This period includes 2 study visits. During visits, the seizure diary will be collected, the study drug will be given to participants, and health checks will be done.

Follow-up Period (2 to 4 weeks):

Participants who stop treatment early or do not wish to enter the Optional Extension Period will need to attend an end of study visit . After this, participants will complete a follow-up period which includes 1 follow-up visit (with a few exceptions). During this follow-up visit, health checks will be done.