The objectives of this study were to assess the tolerability and safety of E2007 in patients with refractory partial or generalised seizures and to assess the pharmacokinetics of E2007 in epileptic patients receiving at least one concomitant anti-epileptic drug.

Inclusion Criteria

A patient who met the following inclusion criteria was eligible to participate in the study:

1. Males or females with simple or complex partial seizures with or without secondary generalization, or primary generalized tonic-clonic seizures according to the International League against Epilepsy classification. Patient records were to document the frequency of seizure.
2. Age: 18 to 65 years.
3. Race: any.
4. Patients receiving up to two additional anti-epileptic medications at doses that were stable for at least the four weeks immediately preceding baseline.
5. Patients willing and able to co-operate with the study procedures including completion of patient diaries.
6. Patients living at home with a partner or carer able to monitor compliance.
7. Patients giving informed consent to participate in the study.

Exclusion Criteria

A patient who met the following exclusion criteria was not eligible to participate in the study:

1. Pregnant or lactating women.
2. Women of childbearing potential unless (1) surgically sterile or (2) practicing effective contraception (eg, abstinence, IUD or barrier method plus hormonal method) and having a negative serum beta-HCG result at screening and being willing to remain on the current form of contraception for the duration of the study. Postmenopausal women could be included but were to have been amenorrhoeic for at least 12 months to be considered as not being of child-bearing potential.
3. Fertile men not willing to use reliable contraception or with partners not willing to use reliable contraception.
4. Patients with status epilepticus within the past 24 months.
5. Patients with unstable abnormalities of the hepatic, renal, cardiovascular, respiratory, abdominal, haematological, endocrine or metabolic systems which might complicate assessment of the tolerability of the study medication.
6. Patients with significantly elevated liver enzymes (abnormal bilirubin level, or serum transaminase levels more than 1.5 times the upper limit of normal).
7. Patients taking drugs other than anti-epileptic agents which induce the enzyme cytochrome P450 3A4 (since these might reduce the plasma concentration of E2007), including dexamethasone, rifabutin, rifampacin, St John's Wort.
8. Patients with past or present drug or alcohol abuse.
9. Patients with unstable psychiatric illness.
10. Patients who had received an investigational drug within the three months before baseline.
11. Patients without a reliable partner or carer.
12. Patients with any condition which would make the patient, in the opinion of the investigator, unsuitable for the study.