Abstracts

Rationale: This is an interim analysis of a multicenter, prospective, noninterventional study of brivaracetam (BRV) conducted in 33 sites in the US (EP0088). This study evaluates outcome of adult patients with focal epilepsy who were initiated on brivaracetam by their physicians. The objective is to assess the real-world effectiveness of BRV. An important secondary objective is to explore whether retention of BRV is associated with lifetime failure of one of 4 prior common antiepileptic drugs (AEDs): levetiracetam (LEV), lamotrigine (LTG), oxcarbazepine (OXC), carbamazepine (CBZ). Methods: Enrolled patients received adjunctive BRV treatment; entry criteria included history of focal seizures in patients ≥16 years. Patients must have a lifetime history or current concomitant use of at least one of 4 common AEDs. Study visits occurred at 1.5, 3, 6, and 12 months, possibly by telephone, at which time BRV dose, concomitant medications and doses, seizure data, BRV discontinuation (if applicable), adverse events, and PROMIS and SERDAS forms were collected. These forms evaluate emotional state, fatigue, sleep, and disability. Retention was calculated from the time of BRV initiation. Retention rates at 3 and 6 months for the overall population and based on historical (hist) and historical plus baseline concomitant (hist + con) use of the 4 AEDs were evaluated. Results: Of the 237 patients studied (Table 1), 71 were exposed to BRV for <90 days, 34 for 90-<180 days, 57 for 180-<317 days, and 75 for ≥317 days. 222 received at least one dose of BRV for 3 or more months (3 Month Cohort) and 187 for 6 or more months (6 Month Cohort) prior to interim analysis. 71 and 55 patients were on concomitant LEV at BRV initiation in the 3 and 6 month Cohorts, respectively. The most common reasons for BRV initiation were lack of efficacy of current therapy (59.1%) and behavioral side effects of current therapy (30.4%). Retention of BRV overall at 3 months was 166/222 (74.8%; 95%CI: 68.5-80.3) and at 6 months was 130/187 (69.5%; 95%CI: 62.4-76.0). BRV retention at 6 months was similar across both prior AED use subgroups (hist and hist + con, respectively): LEV (70.6%, 72.9%), LTG (61.7%, 63.5%), OXC (65.8%, 69.1%), and CBZ (65.8%, 64.9%) (Figure 1). Of the 237 patients, 92 (38.8%) experienced a TEAE and 30 (12.7%) experienced a serious TEAE. 27 (11.4%) patients discontinued BRV for a TEAE. Common TEAEs leading to discontinuation of BRV occurring in ≥3 subjects included off-label product use (n=5, 2.1%), dizziness (n=4, 1.7%), anxiety, fatigue, focal dyscognitive seizure, generalized tonic-clonic seizure, and intentional product misuse (respectively all at n=3, 1.3%). Three patients died during the study, but none were judged to be drug-related. Conclusions: This interim analysis indicates that retention on BRV (a measure of effectiveness) at 3 and 6 months is similar between patients that had previously failed LEV, LTG, OXC, and CBZ. Funding: This study was a partnership between UCB Pharma, PRA, and the Epilepsy Study Consortium, and funded by UCB Pharma.