The dose of E2007 will start from 2 mg and will be increased by 2 mg every week up to 12 mg (the maximum dose). The dose will be adjusted during 6 weeks (i.e., titration period). Subsequently, the dose will be fixed and maintained during 4 weeks (Maintenance period). Patients must visit study site at Weeks -4, 1, 2, 3, 4, 5, 6, 8, 10 and 14 to confirm.

MTD was defined by participants. For participants who completed treatment, MTD was dose at last administration. For subjects who discontinued due to adverse event (AE), the MTD depended on the number of days within down-titration. If these criteria were not applied, the MTD was determined based on suggestions from the Tolerability and Safety Evaluation Committee.

The percent change in seizure frequency per 28 days during the maintenance period was collected via patient diary cards. This was calculated using the last observation carried forward (LOCF) method.

Orally administered E2007 (2, 4, 6, 8, 10, and 12 mg) once daily before bedtime (in fed administration insofar as possible). The dose started from 2 mg and up-titrated weekly in 2 mg increments up to the maximum 12 mg unless subjects met the following judgment on dose titration: 1.) If meeting titration limiting criteria, 2.) If subjects refused up-titration due to AEs, 3.) If the investigator judged it difficult to up-titrate due to AEs, or 4.) If treatment duration was less than 5 days. Total duration of treatment was 10 weeks from the initial dose.

Safety analysis set

MTD was defined by participants. For participants who completed treatment, MTD was dose at last administration. For subjects who discontinued due to adverse event (AE), the MTD depended on the number of days within down-titration. If these criteria were not applied, the MTD was determined based on suggestions from the Tolerability and Safety Evaluation Committee.

Safety analysis set

Orally administered E2007 (2, 4, 6, 8, 10, and 12 mg) once daily before bedtime (in fed administration insofar as possible). The dose started from 2 mg and up-titrated weekly in 2 mg increments up to the maximum 12 mg unless subjects met the following judgment on dose titration: 1.) If meeting titration limiting criteria, 2.) If subjects refused up-titration due to AEs, 3.) If the investigator judged it difficult to up-titrate due to AEs, or 4.) If treatment duration was less than 5 days. Total duration of treatment was 10 weeks from the initial dose.