Perampanel reduces seizure frequency in patients with developmental and epileptic encephalopathy for a long term

Abstract

Seizures in patients with developmental and epileptic encephalopathies (DEEs) are often highly resistant to various antiseizure medications. Perampanel (PER) is a novel antiseizure medication that non-competitively inhibits the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and is expected to reduce seizure frequency not only for focal seizures and generalized tonic-clonic seizures (GTCS) but also for other seizure types. This study aimed to clarify the long-term therapeutic efficacy and tolerability of PER in patients with DEEs. We analyzed data regarding patients' background characteristics, medication retention, trends in seizure frequency, and adverse events obtained from 24 patients with DEEs who had been on PER treatment for 60 months. The retention rates were 62.5% and 46.9% at 12 and 60 months, respectively. At 60 months after PER initiation, the rate of patients with > 50% seizure reduction was 33.3%, 33.3%, 38.5%, 54.5%, 54.5%, and 36.4% among patients with atypical absence seizures, tonic seizures, focal seizures, GTCS, myoclonic seizures, and atonic seizures, respectively. The frequency of adverse events was 70.8%. PER showed long-term efficacy in various seizure types. PER is a promising treatment option for patients with DEEs.

Keywords: Efficacy & safety; Epilepsy with myoclonic atonic seizures; Lennox-Gastaut syndrome; Long-term; Perampanel.

Fig. 1

The retention rate of perampanel. The retention rate was 67.7% at 6 months, 62.5% at 12 months, 57.3% at 24–36 months, 52.1% at 48 months, and 46.9% at 60 months.

Fig. 2

Efficiency of perampanel based on seizure types. GTCS: generalized tonic-clonic seizure. The rate of patients with > 50% seizure reduction for atypical absence seizures was 40.0% at 12 months, 42.1% at 24 months, 31.3% at 36 months, and 33.3% at 48 and 60 months; for tonic seizures, it was 43.8% at 12 months, 53.3% at 24 months, 25.0% at 36 and 48 months, and 33.3% at 60 months; for focal seizures, it was 29.4% at 12 months, 37.5% at 24 months, 26.7% at 36 months, 30.8% at 48 months, and 38.5% at 60 months; for primary or secondary GTCS, it was 50.0% at 12 months, 42.9% at 24 months, and 54.5% at 48 and 60 months; for myoclonic seizures, it was 57.1% at 12 months, 50.0% at 24 and 36 months, and 54.5% at 48 and 60 months; for atonic seizures, it was 61.5% at 12 months, 46.2% at 24 months, 41.7% at 36 months, and 36.4% at 48 and 60 months.