Long-term Safety, Efficacy, and Quality of Life Outcomes with Adjunctive Brivaracetam Treatment at Individualized Doses in Patients with Epilepsy: An Up to 11-year, Open-label, Follow-up Trial

Objective: To evaluate long-term safety/tolerability of brivaracetam at individualized doses ≤200 mg/d (primary) and maintenance of efficacy over time (secondary) in adults with focal seizures or primary generalized seizures (PGS) enrolled in phase 3, open-label, long-term follow-up trial N01199 (NCT00150800).

Methods: Patients ≥16 years of age who had completed double-blind, placebo-controlled adjunctive brivaracetam trials NCT00175825, NCT00490035, NCT00464269, or NCT00504881 were eligible. Outcomes included safety, efficacy, and quality of life.

Results: The safety set included 667 patients (focal seizures, 97.8%; PGS, 2.2%); the efficacy set included 648 patients with focal seizures and 15 patients with PGS. Overall, 49.2% of patients had ≥48 months of exposure. Treatment-emergent adverse events (TEAEs) occurred in 91.2% of all patients (91.3% of focal seizures group), brivaracetam discontinuation due to TEAEs in 14.8%, drug-related TEAEs in 56.7%, and serious TEAEs in 22.8%. The most common TEAEs in the focal seizures group (≥15%) were headache (25.3%) and dizziness (21.9%). Mean changes from baseline in Hospital Anxiety and Depression Scale scores at last value during 2-year evaluation were -0.7 (standard deviation [SD] = 4.3) and -0.2 (SD = 4.4) overall. In the focal seizures group, median reduction from baseline in focal seizure frequency/28 days was 57.3%, 50% responder rate was 55.6%, and 6-month and 12-month seizure freedom rates were 30.3% and 20.3%, respectively. Efficacy outcomes improved by exposure duration cohort and then stabilized through the 108-month cohort. Mean improvement from baseline in Patient-Weighted Quality of Life in Epilepsy Inventory total score (efficacy set) was 5.7 (SD = 16.1, Cohen's d = 0.35) at month 12 and 6.5 (SD = 18.0, Cohen's d = 0.36) at month 24.

Significance: Adjunctive brivaracetam was well tolerated, with a good safety profile in long-term use in adults with epilepsy at individualized doses. Approximately half of the patients remained in the trial at 4 years. Brivaracetam reduced focal seizure frequency versus baseline. Efficacy improved with increasing exposure duration and remained stable through the 9-year cohort.