Pregabalin add-on therapy using a flexible, optimized dose schedule in refractory partial epilepsies: A double-blind, randomized, placebo-controlled, multicenter trial

Abstract

SUMMARY Purpose: To evaluate the efficacy and safety of pregabalin (PGB) as adjunctive therapy, using a flexible-dosing schedule in Korean patients with refractory partial-onset seizures. Methods: This randomized, double-blind (DB), placebo-controlled trial consists of a 6-week baseline, a 12-week DB treatment, and a 1-week taper phase. Patients having recurrent partial seizures (‡4 seizures during baseline phase) under adequate pharmacotherapy were recruited to be randomized to PGB or placebo (PLC) in a 2 to 1 ratio. Starting dose was 150 mg/day, increased every 2 weeks by 150-mg/day increments up to maximum dose of 600 mg/day. The primary efficacy parameter was response ratio (RRatio) for all partial seizures. Results: A total of 178 patients (119 in PGB, 59 in PLC) were assigned to the study. Median daily doses of PGB and PLC were 367 and 420 mg/day, respectively. RRatio least squares (LS) mean was )35.8 in the PGB group and )23.2 in the PLC group, with estimated difference in RRatios being )12.6 [95% confidence interval (CI): )22.7 to )2.5, p = 0.015] in the intent-to-treat (ITT) population. Analysis of secondary efficacy measures showed a general trend favoring PGB over PLC. Seventyseven patients (64.7%) in the PGB group and 18 patients (30.5%) in the PLC group developed adverse events (AEs) related to the study drug. Seven patients (5.9%) in the PGB group discontinued the study prematurely because of AEs. In the post hoc analysis, a significant weight gain (‡7% of baseline body weight) was found in 24.8% of patients taking PGB, which was more frequent in patients with a lower body mass index (BMI £20). Discussion: PGB was effective and easily tolerable as add-on treatment in an Asian population with refractory partial-onset seizures. KEY WORDS: Pregabalin, Flexible-dosing schedule, Response ratio, Add-on therapy, Tolerability