A Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Adjunctive Cenobamate in Asian Patients With Focal Seizures, With Optional Open-Label Extension

Cenobamate was evaluated in a randomized, double-blind, placebo-controlled, multicenter Phase 3 study (YKP3089C035) in Asian adults with uncontrolled focal seizures despite treatment with 1–3 antiseizure medications. Patients aged 18–70 years with ≥8 focal seizures during an 8-week baseline were randomized to placebo or adjunctive cenobamate 100, 200, or 400 mg/day using the approved titration schedule. Among 519 randomized patients, 516 received treatment and 446 were included in the modified intent-to-treat maintenance population. Median reductions in 28-day seizure frequency during maintenance were 25.9% with placebo versus 42.6%, 78.3%, and 100% with cenobamate 100, 200, and 400 mg, respectively (all P<0.001). During the 12-week treatment period, ≥50% responder rates were 27.9% for placebo compared with 44.9%, 70.1%, and 79.3% for cenobamate, while seizure freedom rates were 0.8%, 8.5%, 19.7%, and 30.6%, respectively. Adverse events increased with dose but were generally manageable; the most common were dizziness and somnolence. These results support the efficacy and tolerability of adjunctive cenobamate in a multinational Asian population.