In the US, perampanel is approved for POS (adjunctive/monotherapy) in patients aged ≥4 years, and PGTCS (adjunctive) in patients aged ≥12 years.

Patients completing Study 311 Core Study (4-week Pretreatment; 23-week Treatment) could enter Extension A (29-week Maintenance; 4-week Follow-up). Psychiatric events and suicidal ideation/behavior were monitored for all patients; clinically significant observations were recorded as TEAEs. In addition, suicidality was assessed via the Columbia-Suicide Severity Rating Scale (C-SSRS) in patients aged ≥6 years.

Overall, 136/180 patients enrolled in the Core Study entered Extension A. During Pretreatment, 64/180 (35.6%) patients had a history of psychiatric disorders. During perampanel treatment, 71/180 (39.4%) patients reported psychiatric TEAEs (Core Study, n=66; Extension A, n=5); 32/71 (45.1%) had a history of psychiatric symptoms. Most common psychiatric TEAEs were irritability (n=24 [13.3%]) and aggression (n=18 [10.0%]). Three (1.7%) patients reported serious psychiatric TEAEs, and 11 (6.1%) patients discontinued due to psychiatric TEAEs (most common: aggression and irritability [n=3 each]). Four (2.7%) patients with no reported lifetime history of suicidality had a positive score on the C-SSRS with perampanel; based on investigator assessment, one of these patients (aged 10 years; PGTCS) was reported to have two adverse events of suicidal ideation, while on perampanel 10 mg/day (maintenance dose) in the Core Study. The events were deemed clinically relevant and recorded as TEAEs though both resolved. No additional TEAEs of suicidality were recorded during Extension A. Three patients had a lifetime history of suicidality; none experienced suicidality with perampanel.

These data suggest long-term perampanel treatment is safe and well tolerated in terms of mental health in pediatric patients with POS or PGTCS, however psychiatric TEAEs should be monitored.

Funding: Eisai Inc.