Eslicarbazepine acetate as adjunctive treatment in partial-onset epilepsy

Objective The aim of the study was to assess the clinical response to eslicarbazepine acetate (ESL) as add-on therapy in adult patients with partial-onset epilepsy by means of the time-to-baseline seizure count method. Methods We retrospectively identified consecutive patients with partial-onset seizures, with or without secondary generalization, prescribed to ESL add-on therapy. The primary endpoint was the time-to-baseline monthly seizure count. Subgroup analysis was performed according to carbamazepine (CBZ)/oxcarbazepine (OXC) status (prior vs never use). Secondary outcomes were the rate of treatment-related adverse events (AEs) and the AEs affecting ≥5% of patients. Results One-hundred and eighteen patients were included. The median time-to-baseline monthly seizure count was 46 (35-101) days in the overall study cohort. The number of concomitant anti-epileptic drugs (AEDs) was associated with the time-to-endpoint (adjusted hazard ratio [adjHR]=2.22, 95% CI 1.18-4.14, P=.013 for two AEDs vs one; adjHR=3.65, 95% CI 1.66-8.06, P=.001 for three or more AEDs vs one). Groupwise, the median times-to-baseline seizure count were 47 (35-97) and 43 (34-103) in patients with prior and never exposure to CBZ/OXC, respectively (P for log-rank test=.807). Adverse events occurred in 53.4% (63 of 118) of patients; the most frequently reported were dizziness (13.6%), somnolence (11.9%), nausea (6.8%), and fatigue (5.1%). Conclusions Add-on ESL improved seizure control and was overall well-tolerated in adult patients with partial-onset epilepsy.