Eslicarbazepine acetate as adjunctive therapy in adult patients with partial epilepsy

To investigate the efficacy and safety of once-daily eslicarbazepine acetate (ESL) when used as add-on treatment in adults with > or = 4 partial-onset seizures per 4-week despite treatment with 1 to 3 antiepileptic drugs (AEDs).

This double-blind, parallel-group, multicenter study consisted of an 8-week observational baseline period, after which patients were randomized to placebo (n=100) or once-daily ESL 400 mg (n=96), 800 mg (n=101), or 1200 mg (n=98). Patients then entered a 14-week double-blind treatment phase. All patients started on their full maintenance dose except for those in the ESL 1200 mg group who received once-daily ESL 800 mg for 2 weeks before reaching their full maintenance dose.

Seizure frequency per 4-week (primary endpoint) over the 14-week double-blind treatment period was significantly lower than placebo in the ESL 800 mg and 1200 mg (p<0.001) groups. Responder rate (> or = 50% reduction in seizure frequency) was 13.0% (placebo), 16.7% (400 mg), 40.0% (800 mg, p<0.001), and 37.1% (1200 mg, p<0.001). Median relative reduction in seizure frequency was 0.8% (placebo), 18.7% (400 mg), 32.6% (800 mg, p<0.001), and 32.8% (1200 mg). Discontinuation rates due to adverse events (AEs) were 3.0% (placebo), 12.5% (400 mg), 18.8% (800 mg), and 26.5% (1200 mg). The most common (>5%) AEs in any group were dizziness, somnolence, headache, nausea, diplopia, abnormal coordination, vomiting, blurred vision, and fatigue. The majority of AEs were of mild or moderate severity.

Treatment with once-daily eslicarbazepine acetate 800 mg and 1200 mg was more effective than placebo and generally well tolerated in patients with partial-onset seizures refractory to treatment with 1 to 3 concomitant AEDs.