The purpose of this study is to evaluate the safety, tolerability and continued efficacy of
perampanel in patients previously enrolled in double-blind, placebo-controlled studies for
Painful Diabetic Neuropathy (PDN) or Post-Herpetic Neuralgia (PHN).
Each patient must meet all of the following criteria to be enrolled in this study:
1. Met and continues to meet all inclusion and none of the exclusion criteria for the
preceding PDN or PHN study and received study drug or placebo under double-blind
2. Completed the preceding double-blind study End of Treatment (EOT) Visit no more than
12 weeks prior to Baseline (Visit 1) for the open-label study. The eligibility status
of patients who do not enroll during this 12 week period will be evaluated on a case
by case basis via discussion between the Investigator and the Sponsor.
3. Males and females ≥18 years of age. Female patients should be either of
nonchildbearing potential as a result of surgery or menopause (1 year after onset),
or of childbearing potential and practicing a medically acceptable method of
contraception (e.g., abstinence, a barrier method plus spermicide, or intrauterine
device [IUD]) for at least 1 month before the Baseline Visit (Visit 1) and for 1
month after the end of the study (Visit 16). They must also have a negative
pregnancy test at Baseline (Visit 1). Female patients using hormonal contraceptives
must also be using an additional approved method of contraception (e.g., a barrier
method plus spermicide or IUD) throughout the study.
4. Provide written informed consent prior to entering the study and prior to undergoing
any study-related procedures.
5. Is reliable, willing, and able to cooperate with the study procedures.
Patients who meet the following criterion will be excluded from this study:
1. Patients who discontinued early for any reason from the preceding double-blind study.
2. Patients who have a clinically significant finding(s) that would make them unsuitable
for the study in the opinion of the investigator or Sponsor.