Antiseizure Medication Perampanel Is Effective, Safe in Pediatric Patients With Epilepsy

After its 2012 approval as an antiseizure medication, perampanel (Fycompa) has been found to be both effective and safe for prolonged treatment in patients with epilepsy between the ages 4 to 12 years, as well as patients aged 12 years and older.

The study evaluated the 24-month outcomes of treatment in both children and adolescents and also compared efficacy and tolerability between the 2 groups. The results of the retrospective, observational, single-center study was published in Scientific Reports.

Three-month and 1-year studies evaluating short-term efficacy of perampanel "could have overestimated the anti-seizure efficacy of [perampanel], especially in patients with scarce seizures. Data regarding the long-term use of [perampanel] for children remain to be investigated," the authors explained.

Brain and encephaloogy in patient with epilepsy during seizure

Perampanel is the first highly-selective, non-competitive antagonist of the alpha-amino-3-hydroxy-5-methyl-4 isoxazole propionic acid (AMPA) receptor approved as an antiseizure medication. Although it has been approved to treat primary generalized tonic-clonic seizures in patients with epilepsy age 12 years and older, few studies have evaluated the efficacy and safety of this drug among children.

The study included 294 patients with epilepsy who received perampanel as an adjunctive treatment between February 2016 to February 2021. At the time of recruitment, patients were aged 4 years and older or less than 19 years old, had 24 months or more of follow-up, and had at least 1 seizure within 3 months before the first perampanel treatment.

Patients who had a 50% or more reduction in seizure frequency were deemed to be good responders to perampanel. Additional clinical factors included in the study were age at the initiation of perampanel, sex, perampanel dose, titration speed, number of concomitant antiseizure drugs, epilepsy type, etiology, seizure onset type, baseline seizure frequency, and delayed development.

Furthermore, patients who discontinued perampanel within the 24-month study period were also counted for tolerability, with reasons for discontinuation and adverse effects recorded.

The median (SD) age at perampanel initiation was 14.2 (12.1-16.2) years with 65 (22.1%) patients aged 12 years and older. Of the total patients, 139 (47.3%) were good responders at 12 months and 144 (49%) at 24 months. Additionally, a 100% reduction in seizures was observed in 36 (12.2%) of patients for more than 12 months.

However, discontinuation of perampanel treatment was observed in 117 (39.8%) of patients, with the most common reason for discontinuation being adverse events, which occurred in 34 (29.1%) patients.

Although the baseline seizure frequency was higher in children older than 12 years compared to patients 12 years and younger, the percentage of seizure reduction and good responders did not significantly vary between groups.

Furthermore, the rate of early discontinuation was higher (P < .001, and the duration of perampanel treatment was shorter in children younger than 12 years (P = .001), with most children in this age group discontinuing treatment due to ineffectiveness. On the other hand, adverse events were the most common reason patients ages 12 years and older discontinued perampanel treatment (P = .045).

Lastly, only slow titration was significantly associated with good responders.

"Remarkably, fewer adverse events and higher percentage of discontinuation due to ineffectiveness were observed in pediatric patients compared to adolescents, showing that the optimal pattern of [perampanel] use may be different among these patients," wrote the researchers.

However, the researchers acknowledged some limitations to the study, including the potential selection bias and being a retrospective study.

Despite these limitations, the researchers believe this study showed real-world findings in a clinical setting, which demonstrated good efficacy and safety of perampanel for a prolonged period in pediatric and adolescent patients.

Reference

Youn SE, Kang H-C, Lee JS, Kim HD, Kim SH. Long-term efficacy and safety of adjunctive perampanel in pediatric patients aged 4–19 years with epilepsy: a real-world study. Scientific Reports. 2023;13(1). doi:10.1038/s41598-023-40594-8