Assess retention rate, safety, and dosing experience of perampanel administered to pediatric patients with epilepsy (<12 years) during routine clinical care.

Perampanel is a once-daily oral antiepileptic drug for partial-onset seizures (POS) and primary generalized tonic-clonic seizures. We report second interim results for pediatric patients from the multicenter, non-interventional, Phase IV, retrospective Study 506 (NCT03208660). 

Data were obtained from medical records of patients initiating perampanel after January 1, 2014. Primary endpoint is retention rate (proportion of patients in Safety Analysis Set [SAS] remaining on perampanel). Safety, efficacy, and dosing experience are secondary objectives.

Interim SAS comprised 605 patients; 68 aged <12 years (mean [standard deviation (SD)] age, 6.7 [3.0] years; female, 55.9%; mean [SD] age at epilepsy diagnosis, 2.0 [2.7] years; mean [SD] time since epilepsy diagnosis, 5.9 [4.1] years). Seizure types included: complex partial, n=33 (48.5%); POS with secondary generalization, n=11 (16.2%); generalized tonic-clonic, n=21 (30.9%). Perampanel was titrated as follows: weekly (25.0% of patients); every 2 weeks (30.9%); every 3 weeks (4.4%); “other” (10.3%); “unknown” (29.4%). Mean (SD) cumulative duration of exposure to perampanel was 14.3 (11.5) months and mean (SD) maximum perampanel dose was 5.4 (3.2) mg. At data cut-off (March 5, 2018), 34 (50.0%) pediatric patients remained on perampanel; 33 (48.5%) had discontinued. Primary reasons for discontinuing included adverse event (AE; n=15 [22.1%]) and inadequate therapeutic effect (n=11 [16.2%]). Retention rates at 3, 6, 12, 18, and 24 months were 82.4% (n=56/68), 66.2% (n=43/65), 61.0% (n=36/59), 53.2% (n=25/47), and 48.6% (n=17/35), respectively. Treatment-emergent AEs were reported by 39.7% patients; most common were abnormal behavior, aggression, and irritability (all 5.9%).

An interim subgroup analysis of the real-world Study 506 suggests daily oral doses of adjunctive perampanel are generally well tolerated, with favorable retention rates for ≤2 years in pediatric patients (<12 years) with epilepsy.

Funding: Eisai Inc.