Safety and Tolerability of Adjunctive Brivaracetam in Pediatric Patients < 16 Years with Epilepsy: An Open-Label Trial

Objective This trial evaluated the short-term safety and tolerability, steady-state pharmacokinetics, and preliminary efficacy of brivaracetam oral solution in children aged 1 month to < 16 years with epilepsy. Methods This was a phase IIa, open-label, single-arm, fixed three-step dose escalation trial of 3-weeks duration (N01263; NCT00422422). Patients were taking one to three concomitant antiepileptic drugs. Brivaracetam oral solution dosage, in two divided daily doses, was increased each week: approximately 0.8, 1.6, and 3.2 mg/kg/day for patients aged ≥ 8 years, and 1.0, 2.0, and 4.0 mg/kg/day for patients aged < 8 years. Results Of the 100 patients enrolled, 90 (90.0%) completed the trial. The safety population comprised 99 patients. Treatment-emergent adverse events (TEAEs) considered drug related by the investigator were reported by 32/99 (32.3%) patients, most commonly (≥ 5%) somnolence (7.1%) and decreased appetite (6.1%). TEAEs were reported by 66/99 (66.7%) patients, most commonly (≥ 5%) convulsion, irritability, pyrexia, somnolence, and decreased appetite. In patients with a history of focal seizures with or without secondary generalization and no primary generalized seizures aged 4 to < 16 years ( n = 34), drug-related TEAEs and TEAE incidences were 47.1% and 67.6%, respectively. Steady-state trough brivaracetam and brivaracetam metabolite plasma concentrations increased proportionally with dose. The ≥ 50% responder rates (all seizure types) were 21.3% (all patients, n = 80) and 36.4% (patients with focal seizures, aged 4 to < 16 years, n = 22). Conclusions This open-label trial in pediatric patients with epilepsy provides preliminary information that short-term, adjunctive brivaracetam treatment is well tolerated and effective. Plasma concentrations of brivaracetam and metabolites increased with increasing dose.