Abstracts

Rationale: Eslicarbazepine acetate (ESL) is a novel voltage-gated sodium channel blocker not approved for use in the United States. Two double-blind, placebo-controlled Phase III studies evaluated ESL once-daily as adjunct therapy in patients with partial-onset seizures. It is not known if the safety of adjunct ESL varies based on concomitant antiepileptic drug (con-AED).Methods: We studied patients (N=797) in the safety population from two studies who received at least 1 dose of study medication (ESL 400 mg QD, 800 mg QD, 1200 mg QD or placebo) added to1-3 concomitant AEDs .A sub-group analysis of the incidence of common treatment-emergent adverse events (TEAEs) by con-AED was conducted for the double-blind portion of the two Phase III studies BIA 2093-301 and BIA 2093-302. The investigator recorded adverse events at each visit from visit 1 and throughout the study (including at early discontinuation and at the post-study visit). Results: The most common TEAEs in the ESL group were dizziness, somnolence, headache, diplopia, nausea, vomiting, abnormal coordination and blurred vision. The most commonly used con-AEDs were carbamazepine (n=471; 59.1%), lamotrigine (n=189; 23.7%), valproic acid (n=190; 23.8%), and topiramate (n=106; 13.3%). There were differences in the incidence of some TEAEs by type of con-AED. In combination with CBZ, the incidences of the most common TEAEs were dizziness (29.4%), headache (14.9%), diplopia (14%), and somnolence (12%), while in combination with other AEDs the most common TEAEs were somnolence (14.7%), dizziness (9.8%), and headache (7.8%). In combination with other AEDs, the incidence was <5% for nausea and vomiting and 2% for abnormal coordination, blurred vision, and diplopia.Conclusions: ESL was well tolerated as adjunctive treatment to con-AEDs. In this analysis, the tolerability of ESL was different in patients who were using CBZ concomitantly. The limitation of this analysis was that most of the patients in both CBZ and non-CBZ groups were on more than a single con-AED. and the impact of these combinations could not be assessed.Studies supported by BIAL-Portela; analysis by Sunovion.