Abstracts

Rationale: Lacosamide (LCS) is a novel antiepileptic drug (AED), with a novel mechanism of action indicated in focal epilepsies with or without generalization. There is lack of information about efficacy and safety of early add-on treatment with new AED, because patients included in randomized controlled trials are much more drug resistant when compared to rea- world patients with epilepsy.Methods: Multicenter prospective observational study in Spain. We analyze after 12 month follow up the efficacy and tolerability of LCS when added to patients with focal epilepsy with or without generalization, as early add-on treatment (EAO), when 1 or 2 prior AED were correctly tested priorly, or to not early add-on treatment (NEAO), when 3 or more AED were previously tested.Results: 73 patients included. Age: 46,32yo (ED:16). Female: 47%. Age at epilepsy onset: 34,15yo (ED: 19,89). Seizure frequency 3 months prior to LCS add-on: Median 7 (ICR: 4,5-12,5). Add-on purpose: uncontrolled epilepsy: 90,4%; Prior AED not tolerated: 9,6%. Type of epilepsy (%) Frontal:17,8; Parietal:4,1; Temporal:47,9; Occipital:1,3; Not filiated: 19%, Multilobar:9,7. Etiology (%): Structural/metabolic: 54,8; Cryptogenic: 45,2. EAO group: 44(60,3%); NEAO: 29(39,7%). Add-on to a Sodium Channel Blocker AED (SB):45(61,6%). Add-on to a non SB (NSB): 27(38,4%). Lacosamide average dose at 12 month endpoint: 187mg. Retention rate: 100% 3months, 82,2% 6m, 79,3% 9m, 76,7% 12m. Efficacy (ITT): Seizure freedom: 11(15,1%) 3m, 25(34,24%) 6m, 28(38,4%) 9m, 35(47,9%) 12m. Responder rate (seizure reduction>50%): 44(60,3%) 3m, 46(63,01%) 6m, 48(65,8%) 9m, 53(72,6%) 12m. Responder rate according to drug-resistant epilepsy (EAO vs NEAO): 34(77,3%) vs 14(48,3%) 9m (p0,01), 36(81,8%) vs 17(32,1%) 12 m (p0,09). Seizure free rate: according seizure frequency 3 months prior to LCS add-on (<5seizures vs >= 5); 12m 14 (77,8%) vs 21 (38,2%); p0,01. According to type of AED(NSB vs SB): 9(33,3%) vs 26(57,8); p0,06. Three patients were on LCS monotherapy at 12m endpoint. Multivariate analysis: Seizure freedom 12m: SB OR 0,14 (p0,007). Cryptogenic etiology OR 0,138 (p0,007). Tolerability (AE/withdrawal): 3m 27/8; 6m 4/0; 9m 3/1, 12m 0/0. No serious AE were reported.Conclusions: Lacosamide is efficacious and well tolerated in focal epilepsy with or without generalization, especially in patients that have tested less that 3 AED previously (early add-on therapy). Seizure freedom is more likely if LCS is added to a non sodium channel blocker or tested in a not cryptogenic epilepsy.