Efficacy and tolerability of adjunctive brivaracetam in adults with uncontrolled partial‐onset seizures: A phase IIb, randomized, controlled trial

Summary Purpose: To evaluate the efficacy and tolerability of adjunctive brivaracetam (BRV), a novel high‐affinity synaptic vesicle protein 2A ligand that also displays inhibitory activity at neuronal voltage‐dependent sodium channels, in adult epilepsy patients with uncontrolled partial‐onset seizures. Methods: A phase IIb, double‐blind, randomized, placebo‐controlled, parallel‐group, dose‐ranging study (N01114; NCT00175929) was conducted in patients aged 16–65 years. To be included in the study, patients were required to have experienced four or more partial‐onset seizures during a 4‐week prospective baseline, despite treatment with 1–2 concomitant antiepileptic drugs. Patients were randomized in a ratio of 1:1:1 to receive BRV 50 mg/day (BRV50), 150 mg/day (BRV150), or placebo. A 3‐week up‐titration period was followed by a 7‐week maintenance period (total treatment period of 10 weeks). Key Findings: A total of 157 patients were randomized (intent‐to‐treat [ITT] population; BRV50 n = 53, BRV150 n = 52, placebo n = 52) and overall 148 (94.3%) completed the study. The percent reduction in baseline‐adjusted partial‐onset seizure frequency/week over placebo during the 7‐week maintenance period (primary efficacy outcome) did not reach statistical significance (14.7% for BRV50 [p = 0.093] and 13.6% for BRV150 [p = 0.124]). However, during the entire 10‐week treatment period a statistically significant difference was observed for both BRV groups (17.7% for BRV50 [p = 0.026] and 16.3% for BRV150 [p = 0.043]). The median percent reduction from baseline in partial‐onset seizure frequency/week during the maintenance period was 38.2% for BRV50 (p = 0.017) and 30.0% for BRV150 (p = 0.113) versus 18.9% in the placebo group. During the treatment period, this was 34.9% for BRV50 (p = 0.004) and 28.3% for BRV150 (p = 0.070) compared with 16.3% for placebo. Fifty percent responder rates during the maintenance period were 23.1% for placebo compared with 39.6% for BRV50 (odds ratio [OR] 2.17, p = 0.077) and 33.3% for BRV150 (OR 1.66, p = 0.261). During the treatment period, 50% responder rates were 17.3% for placebo compared with 35.8% for BRV50 (OR 2.69, p = 0.038) and 30.8% for BRV150 (OR 2.15, p = 0.114). Nine patients were free from partial‐onset seizures during the 10‐week treatment period (five patients [9.4%] in the BRV50 group and three [5.8%] in the BRV150 group compared with one patient [1.9%] in the placebo group). Treatment‐emergent adverse events (TEAEs) reported during the treatment period were mostly mild‐to‐moderate with similar incidence across treatment groups (BRV50 36/53, 67.9%; BRV150 35/52, 67.3%; placebo 37/52, 71.2%). The most frequently reported TEAEs in BRV groups were headache, fatigue, nasopharyngitis, nausea, somnolence, and dizziness, although nausea had a higher incidence in the placebo group. Significance: In this double‐blind, placebo‐controlled, phase IIb study of adjunctive BRV (50 and 150 mg/day) in adults with uncontrolled partial‐onset seizures, the primary efficacy analysis did not reach statistical significance; however, statistically significant differences compared with placebo were observed on several secondary efficacy outcomes. BRV was well tolerated.