Efficacy and safety of branded vs generic lacosamide in epilepsy: a retrospective real-world study

Purpose Lacosamide (LCS) is a third-generation antiseizure medication (ASM) approved for focal-onset seizures and generalized epilepsy. Although the branded formulation, Vimpat®, has shown efficacy and safety, the introduction of generic versions, such as Stutan®, raises concerns about clinical equivalence, especially considering the potential for therapeutic fluctuations that could result in breakthrough seizures or adverse events. This study aimed to compare the real-world efficacy, safety and tolerability of branded lacosamide (Vimpat®) versus its generic counterpart (Stutan®) in patients with focal or generalized epilepsy. Methods A multicenter, retrospective, observational study was conducted at two epilepsy centers in Southern Italy. Sixty adult patients were included and divided into two groups: Group A (n = 30) received branded LCS and Group B (n = 30) received the generic formulation. Data were collected at treatment initiation (T0) and the first follow-up (T1), including seizure frequency, adverse events and dose adjustments. The primary outcome was the responder rate (≥ 50% reduction in seizure frequency), with secondary outcomes including seizure freedom, adverse events and dose changes. Results Baseline characteristics were similar between groups. The average daily LCS dose was significantly higher in the Vimpat® group (275 ± 121 mg) compared to the Stutan® group (168 ± 89 mg, p < 0.001). Despite this, efficacy outcomes were comparable, with 60.0% of patients in Group A and 43.3% in Group B achieving a ≥ 50% seizure reduction (p = 0.08). Adverse events were mild or moderate. Conclusions In this real-world setting, generic LCS (Stutan®) demonstrated comparable efficacy, safety and tolerability to Vimpat®, supporting its clinical use as a valid alternative in epilepsy management.