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

OBJECTIVE

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

METHODS

One-year open-label extension (OLE) study with ESL in patients who completed a randomised, double-blind placebo-controlled trial (study BIA-2093-302; Epilepsy Res. 89 (2010) 278-285). Starting dose was 800 mg once-daily, for 4 weeks; thereafter, dose could be individualised within the 400-1,200 mg range. Doses of concomitant antiepileptic drugs were to be kept stable.

RESULTS

Overall, 325 patients were enrolled (intent-to-treat population); 223 (68.6%) patients completed 1-year of treatment. ESL median dose was 800 mg once-daily. Compared to the baseline period of the double-blind study completed prior to this OLE study, median seizure frequency decreased by 32% in weeks 1-4, and between 37% and 39% thereafter. The responder rate (seizure reduction ≥ 50%) was 37% during weeks 1-4 and thereafter ranged between 38% and 42% per 12-week interval. Proportion of seizure-free patients per 12-week interval ranged between 5% and 11%. Improvements from baseline in several Quality of Life in Epilepsy Inventory-31 (QOLIE-31) and Montgomery Asberg Depression Rating Scale (MADRS) scores were observed. Adverse events (AEs) were reported by 83% of patients. AEs occurring in ≥ 10% of patients were dizziness, headache and somnolence. AEs were usually of mild to moderate intensity.

CONCLUSION

In this study, ESL demonstrated a sustained therapeutic effect and was well tolerated during 1-year add-on treatment of adults with partial-onset seizures. Additionally, significant improvements in quality of life domains and depressive symptoms were observed under long-term treatment with once-daily ESL.