Open Access

Adam Strzelczyk, Clara Zaveta, Felix von Podewils, Gabriel Möddel, Lisa Marie Langenbruch, Stjepana Kovać, Catrin Mann, Laurent Maximilian Willems, Juliane Schulz, Barbara Judith Fiedler, Gerhard Kurlemann, Susanne Schubert-Bast, Felix Rosenow, Isabelle Beuchat

• Objective: This study was undertaken to evaluate the long-term efficacy, retention, and tolerability of add-on brivaracetam (BRV) in clinical practice. Methods: A multicenter, retrospective cohort study recruited all patients who initiated BRV between February and November 2016, with observation until February 2021. Results: Long-term data for 262 patients (mean age = 40 years, range = 5–81 years, 129 men) were analyzed, including 227 (87%) diagnosed with focal epilepsy, 19 (7%) with genetic generalized epilepsy, and 16 (6%) with other or unclassified epilepsy syndromes. Only 26 (10%) patients had never received levetiracetam (LEV), whereas 133 (50.8%) were switched from LEV. The length of BRV exposure ranged from 1 day to 5 years, with a median retention time of 1.6 years, resulting in a total BRV exposure time of 6829 months (569 years). The retention rate was 61.1% at 12 months, with a reported efficacy of 33.1% (79/239; 50% responder rate, 23 patients lost-to-follow-up), including 10.9% reported as seizure-free. The retention rate for the entire study period was 50.8%, and at last follow-up, 133 patients were receiving BRV at a mean dose of 222 ± 104 mg (median = 200, range = 25–400), including 52 (39.1%) who exceeded the recommended upper dose of 200 mg. Fewer concomitant antiseizure medications and switching from LEV to BRV correlated with better short-term responses, but no investigated parameters correlated with positive long-term outcomes. BRV was discontinued in 63 (24%) patients due to insufficient efficacy, in 29 (11%) for psychobehavioral adverse events, in 25 (10%) for other adverse events, and in 24 (9%) for other reasons. Significance: BRV showed a clinically useful 50% responder rate of 33% at 12 months and overall retention of >50%, despite 90% of included patients having previous LEV exposure. BRV was well tolerated; however, psychobehavioral adverse events occurred in one out of 10 patients. Although we identified short-term response and retention predictors, we could not identify significant predictors for long-term outcomes. Key Points Long-term postmarketing data for brivaracetam in 262 patients showed an overall retention rate of 50.8%; At 12 months, the 50% responder rate for brivaracetam was 33.1%, with 10.9% reporting seizure freedom; Previous treatment with levetiracetam (90%) did not impact brivaracetam retention or efficacy; Levetiracetam treatment failure should not preclude brivaracetam introduction; No long-term efficacy predictors could be identified.