Abstracts

Rationale: Perampanel is a once-daily oral anti-seizure drug for partial-onset seizures (POS) and primary generalized tonic-clonic seizures (PGTCS). Study 311 (NCT02849626) was a multicenter, open-label, single-arm study of perampanel oral suspension (0.5 mg/mL) in pediatric patients (aged 4 to <12 years) with POS (with/without secondarily generalized seizures [SGS]) or PGTCS. Patients who completed the 311 Core Study could enter Extension Phase A. Here, we report effects of adjunctive perampanel on cognition, behavior, growth, and development at Week 52 compared with Baseline in Study 311 (Core and Extension). Methods: The Core Study comprised 4-week Pretreatment, 23-week Treatment (11-week Titration; 12-week Maintenance), and 4-week Follow-up (for those not entering Extension A) Periods. Extension A comprised 29-week Maintenance and 4-week Follow-up Periods. Data are summarized for all patients who participated in the Core Study (even if they did not enter Extension A) and those who participated in Extension A (up until their exit point). Change from Baseline was assessed at Week 52 for cognitive function (Aldenkamp-Baker Neuropsychological Assessment Schedule [ABNAS]), behavioral and emotional problems (Child Behavior Checklist [CBCL]), visuomotor skills (Lafayette Grooved Pegboard Test [LGPT]), and growth/development. A high ABNAS, CBCL, and LGPT score indicated greater cognitive problems. Results: Of the 180 patients (mean [standard deviation (SD)] age: 8.1 [2.1] years; 48.9% female) enrolled in the Core Study, 136 entered Extension A. Fourteen (10.3%) patients discontinued from Extension A; the most common primary reason for discontinuation was adverse events (n=5 [3.7%]). For all 180 enrolled patients, mean (SD) duration of exposure of perampanel was 41.5 (17.3) weeks. Change from Baseline to Week 52 for ABNAS is presented in Table 1. For CBCL total problems, mean (SD) change from Baseline to Week 52 was -6.0 (14.0) and -1.6 (14.7) for 1.5-5 (n=17) and 6-18 years (n=102), respectively. Mean (SD) change from Baseline to Week 52 in time to complete LGPT (dominant hand) was 5.3 (48.0) seconds for <=8 years (n=33) and 0.4 (23.2) seconds for >8 years (n=51). Perampanel had no significant impact on growth (height/weight) or development as measured by insulin-like growth factor-1, and thyroid function. Conclusions: There were no clinically significant changes in cognition, behavior, or growth/development parameters following long-term (<=52 weeks) adjunctive perampanel treatment in pediatric patients aged 4 to <12 years with POS, SGS, or PGTCS. Funding: Eisai Inc.