Abstracts

Rationale: Lacosamide is approved as adjunctive therapy for partial-onset epilepsy. The number and type of antiepileptic drugs (AED) tried is associated with prognosis. Real-life studies provide useful information about AED combinationMethods: LACO-EXP was a multicenter, retrospective, 1-year, observational study. Thirteen hospital centers participated in the study. The inclusion criteria were: 1) written informed consent; 2) patients older than 18 years; 3) diagnosis of partial-onset seizures; 4) treatment with lacosamide initiated between September 2009 and November 2011 and according to usual clinical practice; 5) patients with at least 1 partial seizure in the year prior to starting lacosamide. All patients were required to have a minimum follow-up duration of one year. The source of data was patient clinical records collected by physicians. It included demographic data, past AED history, epilepsy type, number of seizures (efficacy), adverse events (AE; safety), and changes in the concomitant AED at each clinic visit (when a new AED is started there is, as a minimum, a baseline visit and visits at 3, 6 and 12 months)Results: Five hundred patients met the criteria for inclusion in the study. The monthly seizure frequency at baseline was 11. One hundred two patients (20.4%) had received 1 or 2 AEDs before lacosamide (early add-on group) and three hundred ninety-eight patients (79.6%) received lacosamide after at least 3 AEDs (late add-on group).The responder rate ( 50% seizure reduction) was 57.1% at 12 months and seizure-free rate (for at least six months) was 14.9%. The seizure-free rate was higher in patients with vascular epilepsy (44.1%). Responder and seizure-free rates were significantly higher in the early add-on than in the late add-on group, 74.7% versus 52.6%, and 41.4% versus 8.1%, respectively (both p<0.001). Treatment response to lacosamide was still possible when patients had tried up to 13 AEDs before and seizure freedom when patients had tried up to 10 AEDs before.Seizure-free rates were significantly higher in the non-SCB than SCB group at 12 months 27.1% vs 10.3%(p<0.001). However when mechanisms of action were compared in the early add-on and late add-on groups, differences in seizure-free rates between non-SCB and SCB groups were statistically significant only in the late add-on group (p=0.023). Cumulative lacosamide-related AEs occurred in 39.6% of patients at 12 months.There were fewer AEs at 12 months in the non-SCB than in the SCB subgroup (31.9% vs 42.5%; p=0.029). The most frequent AE was dizziness. The cumulative number of patients who discontinued lacosamide because of an AE was 46 (9.2%) at 12 months. The proportion was higher in the SCB than non-SCB group, although not statistically significant (10.9% vs 8.6%; p=0.425)Conclusions: The addition of lacosamide in patients with partial-onset epilepsy was associated with a clinically significant response to treatment in more than half the patients after 12 months. Treatment response was still possible at the late stage of treatment. Lacosamide was generally well tolerated