Abstracts

Rationale: The objective of this post hoc analysis was to explore the efficacy and safety of lacosamide (LCM) as first adjunctive treatment for partial-onset seizures (POS) in the subgroup of Hispanic/Latino patients from Mexico. Methods: This multinational open-label trial (NCT00955357) enrolled patients with uncontrolled seizures (≥3 POS and ≤40 POS/28 days during the 3 months before study entry) despite appropriate prior treatment. Adjunctive LCM was initiated at 100 mg/day and increased by 100 mg/day each week to the target dose of 400 mg/day. Patients were enrolled to one of two cohorts: LCM as first add-on to an initial monotherapy at ≤24 months since diagnosis, or as later add-on to 1-3 concomitant AEDs, after ≥2 previous AEDs, at ≥5 years since diagnosis. The primary efficacy variable was the proportion of patients achieving seizure freedom for the first 12 weeks of the 24-week Maintenance Phase. Secondary efficacy variables included proportions of patients achieving ≥50% and ≥75% reduction in seizure frequency/28 days from Baseline to Maintenance Phase, and change in Quality of Life Inventory in Epilepsy-31-P (QOLIE-31-P) scores from Baseline to end of treatment. Results: Among 456 patients who received at least one dose of LCM, 102 (22.4%) were enrolled in Mexico with Hispanic/Latino ethnicity (22 as first add-on, 80 as later add-on). Of these 102 patients, 97 had ≥1 post-Baseline seizure assessment and 80/102 completed the first 12 weeks of the Maintenance Phase. Mexican patients were slightly younger than patients enrolled outside Mexico (34.3±11.0 years vs 40.8±13.8 years), with no difference between first and later add-on. In the later add-on cohort, Mexican patients had fewer lifetime AEDs than non-Mexican patients (13% [10/80] vs 39% [108/280] ≥4 AEDs). Among the Mexican patients completing the first 12 weeks of Maintenance, 16% (13/80) were seizure-free during this period: 31% (5/16) of first add-on and 13% (8/64) of later add-on. Similar seizure freedom rates were observed for Mexican patients who completed 24 weeks of Maintenance (Table). Mean change from Baseline in QOLIE-31-P total score in Mexican patients showed an improvement of 5.9±14.5 overall, 11.9±15.5 in the first add-on cohort, and 4.3±13.9 in the later add-on cohort, with improvements seen for all QOLIE-31-P subscales in the first add-on cohort. The most common treatment-emergent adverse events (TEAEs) reported overall by Mexican patients were dizziness (32% [7/22] first add-on and 25% [20/80] later add-on), headache (5% [1/22] and 23% [18/80]), and somnolence (5% [1/22] and 20% [16/80]). Few Mexican patients discontinued due to TEAEs (5% [1/22] first add-on and 9% [7/80] later add-on). Conclusions: LCM initiated as first adjunctive treatment was effective in achieving seizure freedom and was well tolerated in Mexican patients of Hispanic/Latino ethnicity who had uncontrolled POS. Observations from this subgroup were consistent with those in the remainder of the study population. Funded by UCB Pharma