Abstracts

RATIONALE: The short-term safety and efficacy of oxcarbazepine (OXC) as monotherapy and adjunctive therapy in patients with seizures of partial onset was demonstrated in a number of double-blind trials. The purpose of this study was to evaluate the long-term safety and efficacy of oxcarbazepine in patients with medically refractory partial epilepsy.
METHODS: Patients with medically refractory partial epilepsy enrolled in a multicenter, randomized, double-blind, dose-response clinical trial of oxcarbazepine monotherapy (Beydoun et al., 2000) could participate in the long-term open-label extension phase. The open-label extension consisted of patient visits scheduled at 4-week intervals for the first 3 visits and every 12 weeks thereafter. At each visit, an interim physical examination and routine laboratory analysis were performed, and all seizures, concomitant medications and adverse events were recorded. In this study, we reviewed the safety, tolerability and efficacy data during the first 48 weeks of the open-label phase. The change in seizure frequency throughout the first 48 weeks of open-label treatment was compared to the baseline seizure frequency obtained from patients prior to enrollment in the core trial.
RESULTS: Of the 87 patients enrolled in the core trial, 76 patients were enrolled in the open-label phase and provided at least one safety or efficacy data. 42 patients were treated with monotherapy and 34 were on polytherapy at some time during the open-label phase. A total of 56 patients (73%) completed at least 48 weeks of follow-up in the extension phase. Based on an intent-to-treat analysis, the 50% and 75% responder rates were 46%, and 25% respectively, with 6.6% of patients remaining seizure-free throughout the 48 weeks. Similar results were obtained following an evaluable group analysis. A comparison of the efficacy results achieved during the first 24 weeks and subsequent 24 weeks of open label treatment showed that the efficacy of OXC was sustained. OXC was well tolerated with only 13% of patients exiting because of adverse events. The most common adverse events, irrespective of their causal relationship to OXC, were dizziness, headache, fatigue, diplopia, nausea and rash. For the most part, these adverse events were transient.
CONCLUSIONS: The efficacy of oxcarbazepine as monotherapy and adjunctive therapy is sustained during long-term treatment in patients with medically refractory partial epilepsy. It is safe and well tolerated by the majority of patients.
Support: Novartis
Disclosure: Salary - Novartis (D[ssquote]Souza); Grant - Novartis; Stock - Novartis (D[ssquote]Souza); Honoraria - Novartis