摘要Background Perampanel(PER)has gained interest as initial monotherapy for pediatric patients.Currently,there are limited studies on the PER monotherapy in treating pediatric patients with focal-onset seizures(FOS).This study aims to investigate efficacy and safety/tolerability of PER as initial monotherapy in treating pediatric patients with newly-diagnosed FOS in routine clinical practice in China.Methods This multicenter,prospective,real-world observational study enrolled 210 antiseizure medication-na?ve patients aged 4-12 years with newly-diagnosed FOS who visited one of the eight tertiary hospitals in China during March-December 2023.All patients were treated with PER monotherapy.The primary endpoint was seizure-freedom rate(SFR)during weeks 13-26 of PER monotherapy.Furthermore,50％,75％responder rates and retention rate were assessed.An electronic seizure diary was used.Treatment-emergent adverse events(TEAEs)were recorded.Results The full analysis set included 203 patients.The SFR was 158/203,namely,77.8％(95％confidence interval:71.6％-83.0％)during weeks 13-26.The 50％and 75％responder rates were 88.2％and 85.2％,respectively,and the 26-week reten-tion rate was 91.1％.Most patients received 2-6 mg/day maintenance PER and the 107 patients receiving 4 mg/day PER had the highest SFR(89.7％).Patients who had＞2 seizures during the three months before their enrollment were significantly less likely to be seizure free during weeks 13-26 than those who had ≤2 seizures.Seventy-nine(38.9％)patients had treatment-related TEAEs and most of them were mild and tolerable.Two(1.0％)patients withdrew from the study due to TEAEs.The most common TEAEs were dizziness,irritability,somnolence and fatigue.Conclusions PER as initial monotherapy was effective and tolerable in Chinese patients aged 4-12 years with newly-diag-nosed FOS.No safety issues arose in our study.