Lacosamide Monotherapy Up to 800mg Safe for Partial-Onset Seizures

Lacosamide was generally well tolerated in patients with partial-onset seizures.
Lacosamide was generally well tolerated in patients with partial-onset seizures.

VANCOUVER, BC—Lacosamide monotherapy at higher than the currently recommended dose is safe and effective for the treatment of partial-onset seizures, a 2-year open-label extension study reported at the 68th Annual AAN Meeting has found.

Of 322 patients with partial-onset seizures enrolled in a study to establish the effectiveness of lacosamide as monotherapy for this patient population, 210 (65.2%) completed the extension trial, 190 of whom were on lacosamide monotherapy, noted David Vossler, MD, of the Neuroscience Institute in Renton, WA. Median lacosamide monotherapy duration was 587.0 days, with 383.1 subject-years.

The most common dosage ranges were >300–400mg/day (33.6%), >400–500mg/day (21.9%), >500–600 mg/day (20.9%), >600–700mg/day (8.9%), and >700mg/day (3.8%). The recommended dose is 150–200mg twice daily.

Compared to baseline seizure rate in the initial study, during their first 3, 6, 9, 12, 18, and 24 months of lacosamide monotherapy, 163/260 (62.7%), 148/232 (63.8%), 124/194 (63.9%), 121/179 (67.6%), 107/152 (70.4%), and 92/124 (74.2%) of patients had a 50% reduction in seizure frequency.

Rates of those who had a 75% reduction showed a similar trend: 102/260 (39.2%), 96/232 (41.4%), 87/194 (44.8%), 89/179 (49.7%), 83/152 (54.6%), and 71/124 (57.3%), respectively. Corresponding seizure freedom rates starting from Day 1 of monotherapy were 37/260 (14.2%), 20/232 (8.6%), 13/194 (6.7%), 12/179 (6.7%), 8/152 (5.3%), and 7/124 (5.6%), respectively. 

Of the 258 patients exposed to lacosamide therapy for 12 months, 179 (69.4%) achieved lacosamide monotherapy for ≥12 months, and 126/216 patients (58.3%) exposed for 24 months achieved lacosamide monotherapy for ≥24 months.

A total of 54 patients (16.8%) experienced serious adverse events. The most common treatment-emergent adverse events were convulsion, syncope, status epilepticus, and post-ictal state.

"Three patients died during the study (cardiac arrest, metastatic cancer, and sudden unexplained death in epilepsy); each was considered by the investigator to be not related to study medication," the investigators reported.

The study was sponsored by UCB Pharma. Dr. Vossler has received support from, and/or has served as a paid consultant for UCB Pharma.