MonoPER study: Effectiveness and tolerability of PERampanel in monotherapy in real‐world after 12 months of treatment

To evaluate the effectiveness, tolerability, and retention of PER as monotherapy in adults with focal or idiopathic generalized epilepsy over a 12-month period in routine clinical practice. In this single-center, ambispective, noninterventional observational study, 74 patients (age 18-90 years) initiated PER monotherapy-either as first-line treatment (n = 21) or conversion from another antiseizure medication (n = 53)-and were followed for 12 months. Demographic and clinical variables, prior antiseizure regimens, indication for PER initiation (suboptimal seizure control, adverse effects, or sleep improvement), PER dosage, seizure outcomes (seizure freedom and ≥ 50% reduction), and adverse events (AEs) were recorded at 6- and 12-month visits. Retention rates were calculated, and safety was assessed by AE reports and discontinuations. The mean PER dose was 7.22 ± 1.71 mg/day, with 85.1% of patients remaining on monotherapy at 12 months (first-line: 90.5%; conversion: 83.0%). Overall, 70.3% of patients achieved seizure freedom at 12 months (first-line: 81.0%; conversion: 66.0%), and 79.7% were ≥ 50% responders (first-line: 85.7%; conversion: 75.5%). In patients initiated for sleep improvement (n = 24), hypnotic medications were withdrawn in 87.5%, and 79% reported better sleep. AEs were reported in 46.2% of patients at 12 months, most commonly somnolence (28.4%), dizziness (18.9%), and irritability (10.8%). Severe AEs leading to discontinuation occurred in 6.7% of cases. In a real-world cohort, PER monotherapy demonstrated high rates of seizure freedom and retention, with a manageable safety profile. These findings support PER as an effective and tolerable monotherapy option for adult patients with focal or idiopathic generalized epilepsy, corroborating similar observations in recent Epilepsia Open studies of antiseizure monotherapy. Perampanel (PER) is approved as an add-on treatment for seizures, but information on its use alone (monotherapy) is scarce. We studied 74 adults who started PER by itself-either as their first treatment or after stopping another medication-over 1 year. Eighty-five percent stayed on PER for the full year. Seventy percent became seizure-free, and nearly 80% had their seizures cut by at least half. In those taking PER to improve sleep, most could stop sleep-aid drugs and reported better rest. Side effects (mostly mild sleepiness, dizziness, or irritability) occurred in about half of patients, but only 7% stopped PER because of them. Our results suggest that PER alone works well and is generally well tolerated in everyday clinical practice.