Topiramate as adjunctive therapy in refractory partial epilepsy: Pooled analysis of data from five double-blind, placebo-controlled trials

A pooled analysis of data from five similarly designed double-blind, placebo-controlled trials of topiramate (TPM) as add-on therapy in patients with partial epilepsy was performed. The pooled analysis allowed evaluation of efficacy end points and response to treatment for a number of study subgroups not statistically evaluable in the individual study analyses due to limited sample sizes. The five trials included 534 patients, 360 who received TPM at target dosages of 200-1,000 mg daily and 174 who received placebo. In the intent-to-treat pooled analysis, TPM was significantly (p less than or equal to 0.01) superior to placebo in reducing total seizures by greater than or equal to 75% or by 100%. When seizure types were evaluated independently, TPM significantly (p less than or equal to 0.001) reduced the frequency of simple partial, complex partial, and secondarily generalized seizures. TPM was significantly (p less than or equal to 0.001) better than placebo regardless of gender, patient age, baseline seizure rate, and concomitant AEDs. The efficacy of TPM in partial epilepsy is consistent across efficacy end points and across strata defined by study population characteristics.