Levetiracetam extended release for the treatment of patients with partial-onset seizures: A long-term, open-label follow-up study

• Treatment duration ranged from 5.5 months to 24.6 months.
• No patients discontinued due to lack of efficacy or loss of follow-up.
• Most TEAEs were mild or moderate in severity, headache was the most common.
• The mean percentage of seizure-free days ranged from 85.7% to 100.0% with LEV XR.
• LEV XR was well tolerated as monotherapy or adjunctive therapy.

SummaryThis was an open-label study (N01281 [NCT00419393]) assessing the long-term safety of extended-release levetiracetam (LEV XR) in patients with partial-onset seizures (POS); the study was a follow-up to a double-blind, randomized, historical controlled, multicenter, conversion to monotherapy study (N01280 [NCT00419094]). Eligible patients initially received LEV XR 2000 mg/day; dose adjustments and the addition of other antiepileptic drugs (AEDs) were permitted. Overall, 190 patients were enrolled, 189 (99.5%) received LEV XR (safety and efficacy populations) and 166 patients (87.4%) completed the study. The study duration in completed patients was 5.5–24.6 months. Mean daily dose of LEV XR was 2131 mg/day. Treatment-emergent adverse events (TEAEs) occurred in 126 patients (66.7%); most were of mild or moderate severity. Five patients (2.6%) had a TEAE that led to treatment discontinuation. Treatment-emergent serious adverse events occurred in 22 patients (11.6%). Twenty-six patients (13.8%) experienced a psychiatric TEAE. The median 7-day normalized POS frequency was: 1.38 at N01280 study baseline; 0.50 at the first visit of N01281 (last visit of N01280); and 0.00–0.36 between all subsequent visits. Overall, 171 patients (90.5%) entered the N01281 study on LEV XR monotherapy; 65.3% (32/49) of patients remained on monotherapy for 12 months and 47.1% (8/17) for 18 months. While remaining on LEV XR monotherapy, 27/139 patients (19.4%) were seizure-free at 6 months and 8/49 (16.3%) at 12 months. In conclusion, LEV XR was well tolerated when administered as long-term monotherapy or in combination with other AEDs in patients with inadequately controlled POS.