Impact of long‐term treatment with cenobamate on concomitant usage of antiseizure medications: A real‐world retrospective study in Spain

Objectives This study explored the safety and effectiveness of adjunctive cenobamate (CNB) in patients with different levels of drug‐resistant epilepsy (DRE) in a real‐world setting, including its impact on the use of co‐antiseizure medication (co‐ASM). Methods This was a single‐center, retrospective, observational study. Adults with refractory seizures who had received ≥2 previous ASMs and had been treated with CNB for at least a year were included. Effectiveness and safety endpoints were assessed at 3, 6, 12, and 24 months after CNB was initiated. Co‐ASM use was assessed at every visit. Results Ninety‐four patients were included; 23 of 94 (24.5%) had received ≤4 previous ASMs and 70 of 94 (74.5%) had received ≥5 previous ASMs. Patients with ≥5 previous ASMs had a younger age at onset (mean 12 vs 25.9 years) and a longer duration of epilepsy (mean 28.1 vs 16.7 years) compared with patients with ≤4 previous ASMs. The mean CNB daily dose was 310 ± 76.7 mg at 2 years. The mean number of co‐ASMs received by patients was reduced significantly between baseline and all time points ( p ≤ .01). The mean defined daily dose (DDD) per patient (not including CNB) was also reduced significantly across all time points ( p < .01), falling from 3.2 ± 2.3 at baseline to 1.2 ± 1.9 at the 2‐year follow‐up. At 1 and 2 years after initiation of CNB, 79.6% and 80% of patients had a ≥50% reduction in seizure frequency and 36.6% and 30.9% were seizure‐free, respectively. At 2 years, 73.2% of patients reported their condition to be “Very much better” or “Much better” compared with baseline; 37.5% reported treatment‐related adverse drug reactions at 2 years. Significance In patients with DRE, CNB treatment allowed long‐term high seizure‐freedom rates and significant reductions in co‐ASM use, while also achieving both good tolerability and high patient satisfaction scores.