Abstracts

RATIONALE: To evaluate the 2-year long-term safety and efficacy of oxcarbazepine (OXC) in patients with inadequately controlled partial-onset seizures who had completed a double-blind, dose-controlled study.
METHODS: During the randomized, double-blind portion of the study, patients who experienced 2-40 partial-onset seizures during the Baseline Phase while on 1-2 antiepileptic drugs (AEDs) were randomized to 300 or 2400 mg/day OXC and their background AEDs were discontinued. Patients completed the study by receiving 126 days of double-blind treatment or by meeting one or more predefined exit criteria. Eligible patients for the open-label extension entered an 8-day Blinded-Conversion Period in which patients randomized to 300 mg/day had their dose titrated to 2400 mg/day, while patients randomized to 2400 mg/day continued on this dose of OXC. Thereafter, the OXC dose was individualized to provide optimal seizure control with acceptable tolerability. The maximum allowable dose was 3000 mg/day except with monitor approval. Concomitant AEDs were allowed during the Open-label Extension Phase. We report the 2-year safety and efficacy results. The efficacy results were obtained by comparing the seizure frequency during the open-label extension to the prospective Baseline phase that preceded the core trial.
RESULTS: Of the 77 patients (42% men, 58% women) who were enrolled in the long-term Open-label Extension Phase, 35 completed 2 years of therapy. The reasons for exiting were unsatisfactory seizure control (26%), adverse events (18%), and other (10%). Overall, 47% of patients receiving OXC experienced a 50% or better reduction in seizure frequency and 7% remained seizure-free throughout the 104 weeks of open-label therapy. Compared to baseline, 58% of the patients receiving OXC as monotherapy were responders, and 11% were seizure-free. In contrast, 37% of patients receiving OXC as adjunctive therapy were responders and 3% were seizure free. The most common adverse events were dizziness (46%), headache (32%), fatigue (30%), diplopia (30%), nausea (26%), abnormal vision (21%), and somnolence (21%). Overall, the adverse events were mild and transient.
CONCLUSIONS: The results indicate that OXC maintains its safety and efficacy as monotherapy and adjunctive therapy during long-term treatment of patients with partial seizures.
[Supported by: Novartis Pharmaceuticals]; (Disclosure: Salary - DSouza - Novartis Pharmaceuticals, Grant - Beydoun, Sachdeo - Novartis Pharmaceuticals, Consulting - Beydoun, Sachdeo - Novartis Pharmaceuticals, Honoraria - Beydoun, Sachdeo - Novartis Pharmaceuticals)