A Long-term Extension Study of E2007 in Patients With Refractory Partial Seizures Uncontrolled With Other Anti-Epileptic Drugs (AEDs)

Safety was assessed by monitoring adverse events (AEs), adverse drug reactions, clinical laboratory parameters, vital signs, 12-lead electrocardiogram, and dependency questionnaire. AEs were graded on a 3-point scale; 1) mild: (Grade 1) discomfort noticed, but no disruption of normal daily activity, 2) moderate: (Grade 2) discomfort reduced or affected normal daily activity, and 3) severe: (Grade 3) incapacitating, with inability to work or to perform normal daily activity. AE severity associated with abnormal changes in laboratory parameters was assessed using the Ministry of Health and Welfare Notification Number 80 "Classification of Severity of Adverse Drug Reactions of Medicinal Products". TEAEs were defined as AEs that emerged during treatment (absent at pretreatment [Baseline]), reemerged during treatment (were present at pretreatment but stopped before treatment), or worsened in severity during treatment relative to the pretreatment state, when the AE was continuous.

Seizure frequency was derived from information (seizure count and type) recorded in the participant diary. The seizure frequency per 28 days was calculated as the number of seizures over the time interval multiplied by 28 and divided by the number of days in the interval. The percent change in 28-day seizure frequency from baseline was assessed for overall seizures, overall partial seizures, overall generalized seizures, and unclassified seizures. Of the 21 participants, 20 participants concomitantly used at least 1 inducer anti-epileptic drug (AED) (carbamazepine, phenytoin, phenobarbital, or primidone), and 1 participant used only non-inducer AEDs. The data is presented as median percent change with full range.

Responder rate (percentage of participants with greater than or equal to 50% reduction in seizure frequency for 28 days in the Treatment Period relative to that for 28 days in the observation period of Study 231 [responder]. If the reduction in seizure frequency is less than 50%, then the participants are considered as non-responders.

LOCF = Last Observation Carried Forward.

Each participant evaluated him/herself for PGIC at Week 52 of the Treatment Period and at the end of treatment (or discontinuation) by comparing seizure conditions during 4 weeks before Week 52 of the Treatment Period and those during 4 weeks before end of treatment (or discontinuation) of the open label extension study with those during 4 weeks before start of the Treatment Period of Study 231. Assessment was implemented based on frequency of seizure, severity of seizures, AEs, and overall conditions using the 7-grade scores. The evaluation used a 7-point scale with the scores 1: Very much improved, 2: Much improved, 3: Minimally improved, 4: No change, 5: Minimally worse, 6: Much worse, 7: Very much worse.

The investigator evaluated each participant for CGIC at Week 52 of the Treatment Period and at the end of treatment (or discontinuation) by comparing medical conditions during 4 weeks before Week 52 of the Treatment Period and those during 4 weeks before end of treatment (or discontinuation) of the open label extension study with those during 4 weeks before start of the Treatment Period of Study 231. Assessment was implemented based on frequency of seizure, severity of seizures, AEs, and overall conditions using the 7-grade scores. The evaluation used a 7-point scale with the scores 1: Very much improved, 2: Much improved, 3: Minimally improved, 4: No change, 5: Minimally worse, 6: Much worse, 7: Very much worse.