Vigabatrin therapy for refractory complex partial seizures: review of major European trials

Complex partial seizures (CPS) are a form of localization-related seizures associated with serious comorbidities and risks. CPS can be difficult to treat and may remain refractory to treatment with antiepileptic drugs (AEDs). Refractory CPS (rCPS) can be hazardous because of the potential for severe dysfunction and bodily harm, sometimes with fatal consequences. Control of seizure activity is critical to the clinical management of CPS. Vigabatrin is a unique AED approved in both Europe and the United States as adjunctive therapy for adult patients with rCPS who have responded inadequately to several alternative treatments. This review focuses on appropriately controlled studies of vigabatrin conducted in Europe. Several double-blind studies randomized those with rCPS to treatment with vigabatrin vs placebo, and two evaluated durability of response to long-term, open-label vigabatrin. Endpoints included seizure frequency, treatment satisfaction, and adverse events (AEs). Efficacy outcomes demonstrated that vigabatrin add-on therapy significantly reduced the frequency of seizures. Long-term studies indicated durability of response and tolerability of vigabatrin therapy for up to several years. Treatment satisfaction data indicated a preference for vigabatrin vs placebo for both physicians and study participants. Vigabatrin was well-tolerated with generally mild AEs considered common to AEDs. Vision effects were not formally monitored in these studies. In European trials, vigabatrin was efficacious as adjunctive therapy for rCPS.