Lacosamide may be used as monotherapy for the long-term treatment of partial-onset seizures in adults, according to results from a 2 year open-label extension study
The data, published in Epilepsia, was collected from participants previously enrolled in a historically-controlled, conversion-to-monotherapy trial (SP902; NCT00520741). Patients enrolled in SP902 who entered and completed the Maintenance Phase or met at least 1 of the exit criterion were eligible for enrollment in the extension study (SP904; NCT00530855).
Ultimately, 322 patients (aged 16-69 years; mean age 40.7) were enrolled in the SP904 extension study, with 210 completing the study. Of the participants, 287 enrolled in the study on lacosamide monotherapy and 151 patients received lacosamide monotherapy for the duration of the study.
Over 90% of participants achieved lacosamide monotherapy during the study, with a median duration of 587 days. The median modal lacosamide dose was 500 mg/day, with the majority of patients taking modal doses >400-800 mg/day.
Among the 292 patients who were on monotherapy at any time during the study, “62.7–74.2% had a ≥50% reduction and 39.2–57.3% had a ≥75% reduction in seizure frequency compared with the baseline seizure rate in the SP902 study,” the authors reported. Additionally, 14.2–5.6% were seizure-free during their first 3, 6, 12, and 24 months of monotherapy. Of the 151 patients who received monotherapy over their entire time in the study, ≥69% had a ≥50% reduction and >49% had ≥75% reduction in seizure frequency.
Ninety-one percent of patients reported treatment-emergent adverse events, including dizziness (27.3%), headache (17.1%), and nausea (14.3%). Serious treatment-emergent adverse events occurred in 35 patients on monotherapy, and included TEAEs coded to convulsion (2.7%) and syncope (0.7%). Three patients died during the study, however all deaths were ruled not related to study treatment.
“One hundred fifty-one patients spent their entire time in the study on LCM monotherapy, with 123 on monotherapy for ≥12 months and 107 on monotherapy for ≥24 months,” the authors wrote “Thus, although a minority of patients who entered this study on monotherapy added an adjunctive AED, presumably to enhance seizure control, the majority of patients remained on monotherapy until they completed or left the study. This is particularly notable because patients entered SP902 as a result of suboptimal seizure control on previous therapy.”
The study was funded by UCB Pharma. David G. Vossler is on the speaker’s bureaus for Eisai, Lundbeck, Sunovion, and UCB Pharma. He is on the advisory board for Eisai. He conducts contract clinical trials for Acorda, Marinus, Pfizer, Sunovion, and UCB Pharma. Robert T. Wechsler has received support from, and/or has served as a paid consultant for, Cyberonics, Eisai, Gerson Lehrman Group, Lundbeck, Sunovion, UCB Pharma, and Upsher-Smith. Paulette Williams, William Byrnes, and Sheila Therriault are employees of UCB Pharma.
Vossler DG, Wechsler RT, Williams P, Byrnes W, Therriault S. Long-term exposure and safety of lacosamide monotherapy for the treatment of partial-onset (focal) seizures: Results from a multicenter, open-label trial. Epilepsia. 2016; doi:10.1111/epi.13502.