Efficacy and safety of perampanel as the first medication for children with newly diagnosed epilepsy: a real-world single-center prospective observational study.

Introduction: Perampanel (PER) is an antiseizure medication (ASM) with a unique mechanism of action. This study aimed to evaluate the clinical efficacy and safety of PER as the initial monotherapy in pediatric epilepsy and investigate the factors linked to its efficacy. Methods: Between August 2021 and August 2023, we conducted a single-center, prospective observational study at Shenzhen Children's Hospital on children with epilepsy treated with PER monotherapy as the initial ASM. The primary outcome indicators were the seizure-free, response, and medication retention rates at 6 and 12 months. Additionally, adverse events (AEs) were also recorded. Results: In this study, 137 patients with epilepsy were included. Among these patients, two patients were lost to follow-up (attrition rate, 1.5%), seven patients discontinued taking PER due to intolerable AEs (discontinuation rate, 5.1%), and finally, 128 patients were retained (63 males, 65 females; mean age, 7.91 ± 2.53 years). The median duration of epilepsy history prior to PER monotherapy was 0.18 years (interquartile range: 0.04-0.59 years), and the mean initial dosage of PER was 2.3 ± 1.2 mg/day. Among the 128 patients, 42 were diagnosed with self-limited epilepsy with centrotemporal spikes (SeLECTS). Thirty-three patients diagnosed with SeLECTS were seizure-free during the 12-month follow-up period after PER administration (seizure-free rate, 78.6%). The response rates of PER treatment at different time points were 92.9% (6 months) and 90.6% (12 months). Additionally, with PER treatment, the seizure-free rate varied over time, with 75.0% (96/128) and 64.1% (82/128) of patients achieving seizure freedom at the 6-month and 12-month follow-ups, respectively. At the follow-up visit, 34 patients experienced AEs. The average AEs rate was 24.8%. Common AEs were dizziness (20 patients), drowsiness (9 patients), and irritability (7 patients), most of which were mild and transient; patients gradually tolerated and were retained by slow titration or adjustment of the maintenance dose of PER. Sixty-four patients who received 4 mg/day of PER had the highest seizure-free rate (70.3%). Discussion: In this single-arm observational study, PER monotherapy proved effective and safe for children with epilepsy. The seizure-free rate at 12 months stood at 64.1% (82/128), showing higher rates in the SeLECTS subgroup (78.6%, 33/42) compared to the non-SeLECTS subgroup (56.9%, 49/86).