Abstracts

Rationale: New antiseizure medications (ASMs) are initiated based on individual patient need for improved seizure control and/or tolerability. We assessed the clinical utility of brivaracetam (BRV) by examining retention rates 6 and 12 months (mo) after BRV initiation to provide an overall assessment of efficacy and tolerability (Dave H, et al. AES 2021; abstract 2.203). Here, we further examine the relationship between baseline (BL) seizure control and clinical characteristics and outcomes on BRV.

Methods: EP0088 was a multicenter, noninterventional study at 33 US sites. Eligibility criteria included history of focal seizures, ≥16 years of age, and lifetime history or current use of ≥1 of 4 common ASMs. Post hoc analyses were performed on the following subgroups: seizure free (SF) and not SF during the 6-mo retrospective BL, and patients who were or were not ≥6 mo SF at any time during BRV treatment.

Results: A total of 250 out of 254 (98.4%) patients initiating BRV had available BL seizure frequency data (SF n=41; not SF n=209). BRV retention at 6 and 12 mo and overall tolerability in SF patients and not SF patients during BL were generally similar (Figure). Compared with not SF patients during BL, SF patients at BL were generally older, had fewer historical and lifetime ASMs, initiated BRV mainly due to behavioral adverse events or other intolerances to current ASMs, and more frequently were taking levetiracetam (LEV) at BRV initiation (Table). Main reason for BRV initiation in not SF patients during BL was lack of efficacy of existing ASMs. 21/41 (51.2%) SF patients at BL were SF for ≥6 mo at any time during BRV treatment. Among SF patients at BL, there was no difference in BL characteristics (Table) and higher rates of BRV retention were observed in SF patients for ≥6 mo during treatment (n=21) compared with those not SF for ≥6 mo (n=20) (Figure). Eighteen of 21 (85.7%) patients who were SF at BL and SF for any ≥6 mo during BRV treatment were SF from the day of BRV initiation. Not SF patients at BL who became SF for any ≥6 mo during BRV treatment (36/209; 17.2%) had a lower number of historical and lifetime ASMs (Table), higher retention rate at 6 and 12 mo, and reported numerically lower incidence of treatment-emergent adverse events (TEAEs), serious TEAEs, and discontinuation due to TEAEs compared with patients who were not SF for any ≥6 mo during the study (Figure). 27/36 (75.0%) patients who were not SF at BL but became SF for any ≥6 mo period during BRV treatment became SF for at least 6 mo from BRV initiation. In SF patients at BL who were taking LEV (n=29), LEV discontinuation status did not affect seizure freedom during BRV treatment (7/15 patients stopping LEV remained SF ≥6 mo vs. 8/14 who continued LEV remained SF ≥6 mo).

Conclusions: BRV showed good retention and tolerability, and response was similar in patients irrespective of seizure control prior to BRV initiation. Patients who became SF ≥6 mo during BRV treatment had high retention rates regardless of BL seizure status, and most were SF from BRV initiation. Fewer patients who achieved ≥6 mo seizure freedom reported TEAEs or discontinued BRV due to TEAEs compared with patients who did not achieve ≥6 mo seizure freedom.

Funding: Sponsored by UCB Pharma