Recruiting

Long-term safety study of seizure medication in children and teens

Plain-English translation of NCT04715646 on ClinicalTrials.gov ↗ · Source last updated July 2026 · Translation generated August 2026 · How we translate trials

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Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.

What is this trial?

This study is testing , a medication that helps control seizures in children and teenagers with epilepsy. Researchers want to make sure the medication is safe and that patients can tolerate it well over a long period of time. Some participants are continuing from earlier studies, while others in Japan are newly enrolling.

While this medication has been tested before, doctors need to understand how safe it is when children take it for extended periods. This information helps ensure the treatment works well without causing serious side effects over time.

Do you qualify?

You likely qualify if…

you are at least 1 month old (for those continuing from previous studies) or between 4 and 16 years old (for those newly enrolling in Japan)
you have been diagnosed with epilepsy, specifically focal-onset seizures that aren't controlled by at least one other anti-seizure drug
you had at least one seizure during the screening period (4 weeks before the study starts)
you have had a recent brain wave test (EEG) showing epilepsy patterns within the last 10 years
you are either continuing from a previous related study or are being directly enrolled in Japan

You likely don't qualify if…

you have severe medical, neurological, or psychiatric conditions that could affect your safety
you are currently in another study testing an investigational medication
you have had suicidal thoughts in the past 6 months (for participants 6 years or older)
you have had a severe seizure called status epilepticus in the 30 days before screening
you had major surgery within 6 months before the study begins

What participation looks like

Participants will take the medication by mouth at doses adjusted for their weight, up to a maximum of 200 mg per day. Researchers will monitor how well patients tolerate the medication over time through regular follow-up visits and may perform blood tests or EEGs to check safety. The exact duration and visit schedule will depend on whether you're continuing from an earlier study or enrolling new in Japan.

AI-generated summary from trial data · Aug 2, 2026 · Not medical advice

Trial locations(36 sites)

United States

Ep0156 259, Hawthorne, New York

Ep0156 237, Durham, North Carolina

Belgium

Ep0156 204, Leuven

Czechia

Ep0156 240, Prague

France

Ep0156 207, Loos