(341) Long-Term Effect of Adjunctive Perampanel on Clinical Global Impression in Pediatric Patients (Aged 4 to < 12 Years) with Partial-Onset or Primary Generalized Tonic-Clonic Seizures in Study 311
Pediatric Neurology Mary Bridge Children’s Neurology Clinic, Tacoma, WA, USA Tacoma, Washington
Rationale: In the U.S., perampanel is approved for partial-onset seizures (POS; adjunctive and monotherapy) in patients aged ≥ 4 years, and adjunctive treatment of primary generalized tonic-clonic seizures (PGTCS) in patients aged ≥ 12 years. Study 311 (NCT02849626) was a multicenter, open-label study of adjunctive perampanel oral suspension in pediatric patients (aged 4 to < 12 years) with POS (with/without secondarily generalized seizures [SGS]) or PGTCS. We report Clinical Global Impression of Change (CGIC) scores to assess the long-term (1 year) effect of adjunctive perampanel on improvement in a patient’s condition during Study 311 (Core and Extension A). Methods: The Core Study comprised 4-week Pretreatment, 23-week Treatment (11-week Titration; 12-week Maintenance), and 4-week Follow-up Periods (for those not entering Extension A). Extension A comprised 29-week Maintenance and 4-week Follow-up Periods. CGIC scores were rated by the investigator on a 7-point Likert scale at Week 52 for the overall population, and by seizure type (POS [with/without SGS]; PGTCS), age (4 to < 7 years; 7 to < 12 years), and concomitant enzyme-inducing anti-seizure medications (EIASMs [defined as carbamazepine, phenytoin, oxcarbazepine, and eslicarbazepine]; with vs without). Only patients with non-missing data were included and CGIC scores were based on observed cases. Results: Overall, 180 patients were enrolled and treated in the Core Study (POS, n=149 [of which 54 had SGS]; PGTCS, n=31). Of these, 136 patients entered Extension A. Of all enrolled patients, 46 were aged 4 to < 7 years and 134 were aged 7 to < 12 years; 48 patients received concomitant EIASMs and 132 patients received non-EIASMs. At baseline (Week 0), 106 (58.9%) patients were classed as either normal (not at all ill), borderline, or mildly ill on the Clinical Global Impression Severity (CGIS) scale, 33 (18.3%) patients were moderately ill, and 41 (22.8%) patients were either markedly ill, severely ill, or extremely ill; the distribution of patients across these categories by seizure type, age group, and concomitant EIASM use is shown in Figures 1A–C. Of 121 patients with non-missing CGIC data at Week 52, 64 (52.9%) patients were classed as very much/much improved, 53 (43.8%) had minimal improvement/no change, and 4 (3.3%) were minimally/much worse vs. baseline. Figures 2A–C show CGIC scores at Week 52 by seizure type, age group, and EIASM use; for all subgroups, the majority of patients were minimally, much, or very much improved, and there were only four patients who were minimally, much, or very much worse, compared with baseline. Conclusions: Adjunctive perampanel substantially improved CGI following 52 weeks of perampanel treatment compared with baseline in > 50% of pediatric patients. The majority of patients (76.5–92.3%) showed improvements in CGI, regardless of seizure type, age, and concomitant EIASM use. At Week 52, no patients were recorded as very much worse compared with baseline across all subgroups. Funding: Please list any funding that was received in support of this abstract.:
