A Study With an Open-label Extension Phase to Evaluate the Efficacy and Safety of Perampanel (E2007) Administered as an Adjunctive Therapy in Subjects With Refractory Partial-onset Seizures

The purpose of this study is to confirm the efficacy and safety of perampanel compared to placebo in patients with refractory partial-onset seizures

• Drug: E2007

  Core study:4 mg group:

  Week 0 Once daily; 2 mg/day,

  Week 1 to Week 18 Once daily 4 mg/day:

  8 mg group: Week 0 Once daily 2 mg/day, Week 1 Once daily 4 mg/day, Week 2 Once daily 6 mg/day,

  Week 3 to Week 18 Once daily 8 mg/day:

  12 mg group: Week 0 Once daily 2 mg/day, Week 1 Once daily 4 mg/day, Week 2 Once daily 6 mg/day, Week 3 Once daily 8 mg/day, Week 4 Once daily 10 mg/day, Week 5 to Week 18 Once daily 12 mg/day Extension study 4 mg group: Week 19 to Week 22 Once daily perampanel 4 mg/day, Week 23 Once daily perampanel 6 mg/day, Week 24 Once daily perampanel 8 mg/day, Week 25 Once daily perampanel 10 mg/day,

  Week 26 to Week 75 or more Once daily perampanel 12 mg/day:

  8 mg group: Week 19 to Week 22 Once daily perampanel 8 mg/day, Week 23 Once daily perampanel 10 mg/day,

  Week 24 to Week 75 or more Once daily perampanel 12 mg/day:

  12 mg group: Week 19 to Week 75 or more Once daily perampanel 12 mg/day

• Drug: Placebo

  Core study:

  Week 0 to Week 18 Once daily placebo, Week 19 to Week 22 Once daily placebo

  Extension study

  Week 19 to Week 22 Once daily placebo:

  Week 23 Once daily perampanel 2 mg/day, Week 24 Once daily perampanel 4 mg/day, Week 25 Once daily perampanel 6 mg/day, Week 26 Once daily perampanel 8 mg/day, Week 27 Once daily perampanel 10 mg/day, Week 28 to Week 75 or more Once daily perampanel 12 mg/day

• Experimental: Perampanel
  Intervention: Drug: E2007
• Placebo Comparator: Placebo
  Intervention: Drug: Placebo

Inclusion Criteria

1. Male or female and greater than or equal to 12 years of age;
2. Have a diagnosis of epilepsy with partial seizures with or without secondarily generalized seizures
3. Subjects with computed tomography (CT) or magnetic resonance imaging (MRI) diagnosis
4. Subjects who had been treated for at least 12 weeks but confirmed to be uncontrolled with more than one standard AED for 2 years before enrollment
5. During the 6-week Prerandomization Phase subjects must have had ≥ 5 partial seizures per 6-week
6. Are on a stable dose and administration of the same concomitant AED(s) for 1 month prior to Visit 1

Exclusion Criteria

1. Presence of nonmotor simple partial seizures only;
2. Presence of primary generalized epilepsies or seizures, such as absences and/or myoclonic epilepsies;
3. Presence or previous history of Lennox-Gastaut syndrome;
4. A history of status epilepticus within 1 year before enrollment in Prerandomization Phase
5. Seizure clusters where individual seizures cannot be counted
6. A history of psychogenic seizures within 5 years before enrollment in Prerandomization Phase