Efficacy and Safety of Eslicarbazepine Acetate (BIA 2-093) as Adjunctive Therapy for Refractory Partial Seizures in a Double-blind, Randomised, Placebo-controlled, Parallel-group, Multicentre Trial

The study was designed to include 3 parts; only the first part is described in this report. Part I of the study was an international, randomized, placebo-controlled, double-blind, parallel group, multicenter clinical study conducted in 19 countries at 173 sites in 653 subjects with refractory simple partial or complex partial seizures, with or without secondary generalization. After screening procedures and confirming eligibility, subjects entered Part I of the study, which consisted of 3 periods.

The first period was an 8 week observation baseline period (Week -8 to Week -1) during which subjects were instructed on how to complete the seizure diary. At the end of the 8 week observational baseline period, eligible subjects were randomized in a 1:1:1 allocation ratio to 1 of 3 treatment groups (with a blinded treatment assignment):

• Placebo
• ESL 800 mg QD
• ESL 1200 mg QD Subjects then entered the second period of Part 1, the 2 week, double blind, up titration period (Week 1 to Week 2). During this period, subjects in the ESL 800 mg group received ESL 400 mg QD, subjects in the ESL 1200 mg group received ESL 800 mg QD, and subjects in the placebo group received placebo QD.

Subjects then entered the third period of Part I, the 12 week, double-blind, maintenance period (Week 3 to Week 14) where subjects in the ESL 800 mg group received ESL 800 mg QD, subjects in the ESL 1200 mg group received ESL 1200 mg QD, and subjects in the placebo group received placebo QD.

At the completion of the maintenance period, subjects who did not enter Part II were to be tapered off study drug while maintaining the blind according to the following down titration procedure: subjects on 800 mg were down titrated to 400 mg for a duration of 2 weeks, and subjects on 1200 mg were down titrated to 800 mg for 1 week and then down-titrated to 400 mg for 1 week and subjects in the placebo group received placebo QD for 2 weeks. During Part I, 1 to 2 concomitant AEDs were allowed in this study and were to be kept stable during the course of the study.