Adverse events are any untoward medical occurrences in a subject administered study treatment, whether or not these events are related to treatment.

Of the 376 subjects who entered the study, 376 are included in this summary based on the Safety Set (SS). SS population: number of subjects treated.

Adverse events are any untoward medical occurrences in a subject administered study treatment, whether or not these events are related to treatment.

Of the 376 subjects who entered the study, 376 are included in this summary based on the Safety Set (SS). SS population: number of subjects treated.

A serious adverse event is any untoward medical occurrences in a subject administered study treatment, whether or not the event is related to treatment, with at least one of the follow outcomes: death, life-threatening, initial inpatient hospitalization or prolongation of hospitalization, significant or persistent disability/incapacity, congenital anomaly/birth defect, or an important medical event that may jeopardize the subject and require a medical/surgical intervention.

Of the 376 subjects who entered the study, 376 are included in this summary based on the Safety Set (SS). SS population: number of subjects treated.

Median percentage change is the median value with respect to the percent change from Baseline across the population of subjects. Percentage change is calculated as 100 times the difference of the seizure frequency for the treatment period and the Baseline seizure frequency divided by the baseline seizure frequency.

Negative changes from Baseline indicate an improvement (i.e., a reduction) in 28-day seizure frequency.

Of the 376 subjects who were enrolled/treated in the study, 376 are included in this summary based on the Full Analysis Set (FAS). FAS population: number of subjects treated with at least 1 post-baseline seizure diary day with available data during the SP774 study.

At least 50 percent response is based on the percentage reduction in 28-day seizure frequency during the Treatment Period of the open-label extension relative to the Baseline Phase of the prior study. This endpoint reflects the percentage of subjects with at least 50% reduction (ie, at least 50% change) in 28-day partial onset seizure frequency

Of the 376 subjects who were enrolled/treated in the study, 376 are included in this summary based on the Full Analysis Set (FAS). FAS population: number of subjects treated with at least 1 post-baseline seizure diary day with available data during the SP774 study.