A Efficacy and Safety Study of Adjunctive Perampanel in Primary Generalized Tonic Clonic Seizures

Inclusion:

Ages 12 years and older

1. Clinical diagnosis of PGTC seizures (with or without other subtypes of primary generalized seizures) and experiencing >/= 3 PGTC seizures during the 8-week period prior to randomization
2. Have had a routine electroencephalogram (EEG) prior to or during the Baseline Period with electroencephalographic features consistent with primary generalized epilepsy; other concomitant anomaly should be explained by adequate past medical history
3. On a fixed dose of one to a maximum of three concomitant antiepileptic drugs (AEDs) for a minimum of 30 days prior to Baseline; only one inducer AED (i.e., carbamazepine, oxcarbazepine, or phenytoin) out of the maximum of two AEDs will be allowed
4. A vagal nerve stimulator (VNS) will be allowed, but it must have been implanted >/= 5 months prior to Baseline (stimulator parameters can not be changed for 30 days prior to Baseline and for the duration of the study).
5. Have had a computed tomography (CT) or magnetic resonance imaging (MRI) within the last 10 years (for adults) and 5 years (for adolescents) that ruled out a progressive cause of epilepsy
6. A ketogenic diet will be allowed as long as the subject has been on this diet for 5 weeks prior to randomization

Exclusion:

1. A history of status epilepticus that required hospitalization within 12 months prior to Baseline
2. Seizure clusters where individual seizures cannot be counted
3. A history of psychogenic seizures
4. Concomitant diagnosis of Partial Onset Seizures (POS)
5. Progressive neurological disease
6. Clinical diagnosis of Lennox-Gastaut syndrome
7. If felbamate is used as a concomitant AED, subjects must be on felbamate for at least 2 years, with a stable dose for 60 days prior to Baseline. They must not have a history of white blood cell (WBC) count below </= 2500/microL (2.50 1E+09/L), platelets < 100,000/microL, liver function tests (LFTs) > 3 times the upper limit of normal (ULN), or other indication of hepatic or bone marrow dysfunction while receiving felbamate.
8. Concomitant use of vigabatrin: Subjects who took vigabatrin in the past must be discontinued for approximately 5 months prior to Baseline, and must have documentation showing no evidence of a vigabatrin-associated clinically significant abnormality in an automated visual perimetry test
9. Concomitant use of barbiturates (except for seizure control indication) within 30 days prior to Baseline
10. Use of intermittent rescue benzodiazepines (i.e., one to two doses over a 24-hour period considered one-time rescue) two or more times within the 30 days prior to Baseline