Open-label Extension Study of the Phase 3 VRX-RET-E22-301 Double-Blind Trial

This Phase 3 trial is an open-label extension study of the placebo-controlled, double-blind
VRX-RET-E22-301 trial. Patients who have completed the VRX-RET-E22-301 trial and who meet
inclusion and exclusion criteria will be treated with 600-1200 mg/day of retigabine as an
adjunct therapy to their current antiepileptic drugs (AEDs) or vagal nerve stimulation.
Treatment will be continued until retigabine is commercially available, or until the program
is discontinued. Patients will be recruited from 45-50 sites in the United States, Canada,
Mexico, Brazil, and Argentina. The safety and tolerability of long-term therapy with
retigabine administered as adjunctive therapy in adult epilepsy patients with partial-onset
seizures will be evaluated. In addition, the efficacy of long-term treatment with retigabine
and patient quality of life will be assessed.

Inclusion Criteria:

- Patient has successfully completed the Maintenance and Transition phases of Study
VRX-RET-E22-301 for the treatment of partial-onset seizures

- Patient is expected to benefit from participation in the study in the opinion of the
Investigator.

Exclusion Criteria:

- Patient meets any of the withdrawal criteria in the previous VRX-RET-E22-301 study or
is experiencing an ongoing serious adverse event.

- Patient is receiving any investigational drug or using any experimental device in
addition to Retigabine for treatment of epilepsy or any other medical condition.

- Patient has any other condition that would prevent compliance with the study
procedures or proper reporting of adverse events.