Perampanel as Adjunctive Therapy in Pediatrics With Partial Onset Seizures or Primary Generalized Tonic Clonic Seizures

Inclusion Criteria

• Have a diagnosis of epilepsy with POS with or without secondarily generalized (SG) seizures or PGTC seizures according to the International League Against Epilepsy's (ILAE) Classification of Epileptic Seizures (1981). A diagnosis should have been established at least 6 months prior to Visit 1 by clinical history and an electroencephalogram (EEG) that is consistent with the diagnosis; normal interictal EEGs will be allowed provided that the participant meets the other diagnosis criterion (that is, clinical history)
• Male or female participant, from age 4 to ) one POS or one PGTC seizure. Only simple POS with motor signs, complex POS, and complex POS with secondary generalization are counted toward this inclusion for POS
• Are currently being treated with stable doses of 1 to a maximum of 3 approved antiepileptic drugs (AEDs). Doses must be stable for at least 4 weeks before to Visit 1; in the case where a new AED regimen has been initiated for a participant, the dose must be stable for at least 8 weeks prior to Visit 1. Only one EIAED (defined as carbamazepine, phenytoin, oxcarbazepine, or eslicarbazepine) out of the maximum of three AEDs is allowed (A vagal nerve stimulator [VNS] will be counted as one of the 3 allowed AEDs)

Exclusion Criteria

• Females who are breastfeeding or pregnant at Screening or Baseline (as documented by a positive beta human chorionic gonadotropin [β-hCG] or human chorionic gonadotropin [hCG] test with a minimum sensitivity of 25 International Units per liter [IU/L] or equivalent units of β-hCG or hCG). A separate baseline assessment is required if a negative screening pregnancy test was obtained more than 72 hours before the first dose of study drug
• Females of childbearing potential who:
• Had unprotected sexual intercourse within 30 days before study entry and who do not agree to use a highly effective method of contraception (example, total abstinence, an intrauterine device, a contraceptive implant, an oral contraceptive, or have a vasectomized partner with confirmed azoospermia) throughout the entire study period or for 28 days after study drug discontinuation. If a highly effective method is not appropriate or acceptable for the participant, then the participant may use a medically effective method (example, a double barrier method such as condom plus diaphragm with spermicide)
• Are currently abstinent, and do not agree to use a double-barrier method (as described above) or refrain from being sexually active during the study period or for 28 days after study drug discontinuation
• Are using hormonal contraceptives but are not on a stable dose of the same hormonal contraceptive product for at least 4 weeks before dosing and who do not agree to use the same contraceptive during the study or for 28 days after study drug discontinuation
• Current or history of pseudo-seizures (psychogenic nonepileptic seizures) within approximately 5 years before Visit 1
• Have a history of status epilepticus that required hospitalization during the 6 months before Visit 1
• Have an unstable psychiatric diagnosis that may confound participants' ability to participate in the study or that may prevent completion of the protocol-specified tests (example, significant suicide risk, including suicidal behavior and ideation within 6 months before Visit 1, current psychotic disorder, acute mania)
• Any suicidal ideation with intent with or without a plan within 6 months before Visit 2 (that is, answering "Yes" to questions 4 or 5 on the Suicidal Ideation section of the Columbia Suicide Severity Rating Scale [C-SSRS]) in participants aged 6 and above
• Are scheduled and/or confirmed to have epilepsy surgery within 6 months after Visit 1; however, those who have previously documented "failed" epilepsy surgery will be allowed
• Evidence of clinically significant disease (example, cardiac, respiratory, gastrointestinal, renal disease) that in the opinion of the investigator(s) could affect the par