Evaluation of adjunctive perampanel in patients with refractory partial-onset seizures: results of randomized global phase III study 305

Epilepsia. 2013 Jan;54(1):117-25. doi: 10.1111/j.1528-1167.2012.03638.x. Epub 2012 Aug 20.


Purpose: To assess the efficacy and safety of once-daily doses of perampanel 8 and 12 mg when added to 1-3 concomitantly administered, approved antiepileptic drugs (AEDs) in patients with uncontrolled partial-onset seizures.

Methods: Study 305 was a multicenter, double-blind, placebo-controlled trial in patients aged 12 years and older with ongoing seizures despite prior therapy with at least two AEDs, and currently receiving 1-3 AEDs. Equal randomization to once-daily oral perampanel 8 or 12 mg, or placebo was performed. Patients entered a 19-week double-blind treatment phase comprising a 6-week titration period, with weekly 2-mg dose increments, followed by a 13-week maintenance period. Primary efficacy end points were the responder rate (proportion of patients who had a ≥50% reduction in seizure frequency during treatment per 28 days relative to baseline), and the percent change in seizure frequency per 28 days relative to pre-perampanel baseline. A secondary end point was percent change in the frequency of complex partial plus secondarily generalized seizures. Adverse events (AEs) were monitored throughout the study.

Key findings: Three hundred eighty-six patients were randomized and treated with study medication. Of these, 321 patients completed the study. The 50% responder rates (intent-to-treat analysis) were 14.7%, 33.3%, and 33.9%, respectively, for placebo, perampanel 8 mg, and perampanel 12 mg, with significant improvements over placebo for both perampanel 8 mg (p = 0.002) and 12 mg (p < 0.001). The median percent change from baseline in seizure frequency per 28 days (intent-to-treat analysis) was -9.7%, -30.5%, and -17.6% for placebo, 8 mg, and 12 mg, respectively, with significant reductions compared with placebo for both 8 mg (p < 0.001) and 12 mg (p = 0.011). For complex partial seizures plus partial seizures that secondarily generalized, the median percent change in frequency was -32.7% (8 mg), -21.9 (12 mg), and -8.1% (placebo), with significant reductions for both 8 mg (p < 0.001) and 12 mg (p = 0.005). The most frequent (occurring in ≥10% of patients in any treatment group) treatment-emergent AEs were dizziness, somnolence, fatigue, and headache, with an apparent dose effect suggested for all except headache.

Significance: This phase III trial demonstrated that adjunctive treatment with once-daily perampanel at 8 mg and 12 mg was effective in improving seizure control in patients 12 years and older with refractory partial-onset seizures. These study results also demonstrated that once-daily doses of 8 mg and 12 mg were safe and acceptably tolerated in this study. Perampanel demonstrated a favorable risk/benefit ratio in this population.

Trial registration: ClinicalTrials.gov NCT00699582.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anticonvulsants / administration & dosage
  • Anticonvulsants / adverse effects
  • Anticonvulsants / therapeutic use*
  • Double-Blind Method
  • Drug Therapy, Combination
  • Epilepsies, Partial / drug therapy*
  • Female
  • Humans
  • Male
  • Nitriles
  • Pyridones / administration & dosage
  • Pyridones / adverse effects
  • Pyridones / therapeutic use*
  • Treatment Outcome


  • Anticonvulsants
  • Nitriles
  • Pyridones
  • perampanel

Associated data

  • ClinicalTrials.gov/NCT00699582