Long-term efficacy and safety of eslicarbazepine acetate: results of a 1-year open-label extension study in partial-onset seizures in adults with epilepsy.

PURPOSE: To evaluate the long-term efficacy and safety of once daily eslicarbazepine acetate (ESL) as adjunctive therapy for partial-onset seizures in adults with epilepsy.

METHODS: One-year open-label treatment extension with ESL in patients who completed a placebo-controlled pivotal study (Epilepsia 2009; 50: 454-463). Starting dose was 800 mg once daily, for 4 weeks; thereafter, dose could be titrated up or down. Doses of concomitant antiepileptic drugs were to be kept stable.

RESULTS: Overall, 314 patients were enrolled. The intent-to-treat population consisted of 312 patients, and 239 (76.6%) completed 1 year of treatment. ESL median dose was 800 mg once daily. Compared to baseline, median seizure frequency decreased by 39% during the first 4 weeks and between 48% and 56% thereafter. The responder rate (≥50% seizure reduction) was 41% during weeks 1-4 and, thereafter ranged between 48% and 53%. The proportion of seizure-free patients per 12-week interval ranged between 8.7% and 12.5%. Quality of life, as measured by the Quality of Life in Epilepsy Inventory-31 (QOLIE-31), and depressive symptoms, as measured by the Montgomery Asberg Depression Rating Scale (MADRS), improved significantly compared to baseline. Treatment-emergent adverse events (TEAEs) were reported by 51% of patients. The most frequent TEAEs were headache (10%), dizziness (10%), diplopia (5%), and nasopharyngitis (5%). TEAEs were mostly (97%) of mild to moderate intensity. Eleven patients (3.5%) discontinued due to TEAEs. There were no results of laboratory tests raising safety concerns.

DISCUSSION: Sustained therapeutic effect, favorable tolerability and safety, and an improvement in quality of life and depressive symptoms were observed during long-term add-on treatment of partial-onset seizures in adults with once daily ESL.