First add‐on perampanel for focal‐onset seizures: An open‐label, prospective study

OBJECTIVES: This study aimed to determine the efficacy and safety of perampanel added to monotherapy in patients with focal‐onset seizures, with or without secondarily generalized tonic‐clonic seizures. MATERIALS & METHODS: In this multicentre, open‐label trial, enrolled patients were treated with perampanel monotherapy. During a 12‐week titration period, perampanel was incrementally increased by 2 mg/d over ≥2‐week intervals. Patients then entered a 24‐week maintenance period. The primary objective was to investigate the 50% responder rate in total seizure frequency, with 75% and 100% responder rates as secondary objectives. Treatment‐emergent adverse events (TEAEs) and adverse drug reactions were recorded. A post hoc analysis was performed to investigate the effect of titration speed and different concomitant AEDs on the efficacy and safety of perampanel. RESULTS: Of the 85 patients analysed, seizure reductions of 50%, 75% and 100% were observed in 80.0% (95% confidence interval [CI]: 69.9‐87.9), 71.8% (95% CI: 61.0‐81.0) and 47.1% (95% CI: 36.1‐58.2) during the maintenance period, respectively. The 50%, 75% and 100% response rates in patients with secondarily generalized tonic‐clonic seizures were 87.5% (95% CI: 61.7‐98.5), 87.5% (95% CI: 61.7‐98.5) and 75.0% (95% CI: 47.6‐92.7), respectively. The most common TEAEs were dizziness (50.0%), somnolence (9.8%) and headache (8.8%). The efficacy outcomes and safety profile of perampanel were more favourable with slow titration and relatively consistent when stratified by concomitant AEDs. CONCLUSIONS: Perampanel was effective and well tolerated as a first add‐on to monotherapy in patients with focal‐onset seizures, with or without secondarily generalized seizures.