Cenobamate Monotherapy for Focal Epilepsy: A Single-Center Retrospective Study.

Background and Objectives: Cenobamate is a novel antiseizure medication (ASM) approved by the Food and Drug Administration for use as adjunctive therapy in focal epilepsy. However, there are limited data on its use as a standalone monotherapy. The aim of our study was to investigate the use of cenobamate monotherapy and evaluate its clinical efficacy and safety in treating focal epilepsy. Methods: This single-center retrospective study was conducted on patients who were transitioned to cenobamate monotherapy for more than 6 months at a daily dosage of at least 150 mg. The cohort comprised patients transitioned from monotherapy and those previously on polytherapy with ASMs. Efficacy was based on the seizure freedom and seizure frequency reduction rates between pretreatment and post-treatment with cenobamate while safety was estimated by the reported adverse events. Results: A total of 527 patients were found to use cenobamate as part of their treatment regimen; 45 patients (9%) were transitioned to cenobamate monotherapy and met our predefined criteria. The median follow-up was 14.6 months. Before treatment with cenobamate, 56% were taking one ASM, 33% two ASMs, and 9% three ASMs. The median dose for cenobamate was 250 mg. The mean seizure frequency on cenobamate was reduced from 4.3 to 0.7 per month; the responder rate (50% reduction in seizure frequency) was achieved at 77%, and 55% of the patients remained seizure-free during the 12-month observation period. Discussion: Cenobamate monotherapy was found to significantly reduce seizure frequency and achieve high seizure freedom rates and was well tolerated in patients with focal epilepsy, highlighting its promise as an emerging alternative for patients with refractory focal epilepsy.