To evaluate long-term retention and reasons for discontinuation of adjunctive brivaracetam (BRV) in adults with focal seizures by number of lifetime anti-epileptic drugs (AEDs).

503 patients randomized to BRV were analyzed (median treatment duration 1008 days). KM estimated retention rates on adjunctive BRV in patients with 1-2 (n=75), 3-4 (n=100), 5-6 (n=108) and 7+ (n=220) lifetime AEDs at 1 year were 82.5%, 72.8%, 72.3% and 65.4%, respectively; at 3 years: 62.1%; 58.5%; 60.0%; and, 46.1%, respectively. The main reasons for BRV discontinuation in patients with 1-2 and 3-4 lifetime AEDs were consent withdrawn (17.3%; 17.0%); adverse event (10.7%, 11.0%) and lack of efficacy (10.7%, 11.0%); in patients with 5-6 and 7+ lifetime AEDs: lack of efficacy (17.6%; 27.3%) and adverse event (16.7% and 20.5%). KM analyses of discontinuation due to lack of efficacy or adverse events showed estimated proportions of patients remaining on treatment at 1 year to be 90.3%, 86.7%, 79.2% and 69.0% in patients on 1-2, 3-4, 5-6, 7+ lifetime AEDs, respectively; the corresponding values at 3 years were: 80.5%; 80.2%; 66.7%; 51.5%.