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 or without secondarily generalized seizures [SGS]) or PGTCS. Patients who completed the 311 Core Study could enter Extension Phase A. Here, we assess the impact of adjunctive perampanel on Health-Related Quality of Life (HRQoL) using the EuroQol 5 Dimensions‑Youth (EQ-5D-Y) scale 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. Cumulative data from all enrolled patients were included (<=23 weeks' of treatment [for those participating in the Core Study] or <=52 weeks [for those participating in the Core Study and Extension A]). The exploratory endpoint EQ-5D-Y was assessed at Baseline, Week 23, and Week 52, and included 5 domains (mobility, self-care, doing usual activities, pain/discomfort, and feeling worried/sad/unhappy). The EQ-5D-Y visual analog scale (VAS) was also assessed; an increase in VAS corresponds to an improvement. Data are presented for observed cases. Results: Of 180 patients enrolled in the Core Study (POS, n=149; SGS, n=54; PGTCS, n=31), 136 patients completed the Core Study and entered Extension A. Table 1 shows the proportions of patients reporting no problems, some problems, or a lot of problems for each of the 5 domains during Baseline and at Week 52. During Baseline, the domain that showed the highest proportion of patients reporting a lot of problems was self-care (39.3%); there were few patients who reported a lot of problems in the pain/discomfort and feeling worried/sad/unhappy domains (both 3.5%). Following up to 52 weeks' of adjunctive perampanel treatment, the overall patterns for all EQ-5D-Y domains were similar to those reported during Baseline; however, in each domain there was a slightly higher proportion of patients reporting no problems at Week 52 compared with Baseline. Mean (standard deviation) change in EQ-5D-Y VAS from Baseline at Week 52 was 5.1 (16.6) for all patients, 5.1 (17.0) for patients with POS, 8.6 (12.3) for patients with SGS, and 5.2 (15.8) for patients with PGTCS (Figure 1). Conclusions: These data indicate long-term adjunctive perampanel treatment (up to 52 weeks) does not negatively affect HRQoL (based on all EQ‑5D-Y domains) in patients aged 4 to <12 years with POS (with or without SGS) or PGTCS. Funding: Eisai Inc.