NEW YORK (Reuters Health) – Pooled data indicate that eslicarbazepine acetate (Zebinix) is effective adjunctive therapy in patients with partial-onset seizures refractory to standard drug treatment.
“The efficacy of eslicarbazepine 800 and 1,200 mg once-daily administered to patients with partial-onset seizures refractory to stable AED (antiepileptic drug) therapy showed consistent results across efficacy endpoints and was independent of population characteristics and concomitant antiepileptic drugs (AEDs),” Dr. Patricio Soares da Silva of Bial – Portela & Co., the drug’s manufacturer, told Reuters Health by email.
In a paper online August 6 in Epilepsia, he and his colleagues note that eslicarbazepine was approved in 2009 by the European Medicines Agency. The company plans to market it as Stedesa in the U.S. if it gets approval from the Food and Drug Administration.
The researchers pooled and analyzed results from three previously published phase III double-blind, randomized, placebo-controlled studies. Most seizures at baseline were either simple-partial or complex-partial, and the frequency for each seizure type was similar in all treatment groups.
In total, 1,049 patients on stable AED therapy underwent a two-week titration period followed by once-a-day eslicarbazepine at 400, 800, or 1,200 mg for 12 weeks.
Over this period, the higher doses of eslicarbazepine led to a significant reduction in seizure frequency (p<0.0001). The median relative reduction with placebo was 15%, compared to 35% with 800 mg and 39% with 1,200 mg daily.
The responder rates (at least 50% reduction in seizure frequency from baseline) were 22% in the placebo group, 36% in the 800 mg group, and 44% in 1,200 mg group.
“The efficacy observed in each dose group,” the researchers say, “was generally comparable for patients taking one AED and those taking two AEDs.”
In fact, performance with the higher doses gave “consistent results across all efficacy end points and was independent of study population characteristics as well as the type and number of concomitant AEDs.”
The incidence of treatment-emergent adverse events (TEAEs) was 46.4% in the placebo group, 62.7% in the 800 mg group and 67.5% in those given 1,200 mg. Discontinuation due to these events was dose-dependent, and ranged from 5% in the placebo group to 19% in the 1,200 mg patients.
“Given that eslicarbazepine 800 mg caused less discontinuation due to TEAEs and presented a lower potential for pharmacokinetic interactions than eslicarbazepine 1,200 mg,” concluded Dr. Soares da Silva, “the combined analyses on these pooled data suggest that eslicarbazepine 800 mg once-daily provides optimal balance of efficacy and tolerability as eslicarbazepine target dose for adjunctive therapy of most patients with partial-onset seizures.”
The study was funded by Bial – Portela & Co.