The impact of seizure frequency on quality of life in patients with Lennox-Gastaut syndrome or Dravet syndrome.

OBJECTIVES: Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare treatment-resistant epileptic encephalopathies with limited data describing the relationship between seizures and quality of life (QoL). The objective of this cross-sectional pilot study was to assess the impact on QoL of seizures and seizure-free days for the generation of utility values. METHODS: Surveys were conducted in the UK and France, whereby patients and/or caregivers of patients with LGS, DS, or other epilepsies were asked to score health state vignettes for a hypothetical patient with LGS or DS. Respondents evaluated QoL for health states based on the number of seizures and seizure-free days per month, using a visual analog scale (VAS). Visual analog scale scores were converted to the 0-1 scale as a proxy estimate for utility values. Surveys were pilot tested and respondents were recruited from October 2018 to August 2019. RESULTS: Patient respondents were mainly treatment-responsive (n = 43/55) whereas caregiver respondents mainly cared for patients with treatment-resistant epilepsy (n = 38/43). Most respondents and patients were aged ≥18 years. Results from LGS and DS surveys in the UK (n = 58) and France (n = 40) suggested that health states with fewer seizures and more seizure-free days had higher QoL scores for hypothetical patients. For DS, QoL scores for patient health states ranged from 0.20 (32 convulsive seizures and 4 seizure-free days/month, UK) to 0.92 (seizure-free, France). For LGS, scores ranged from 0.14 (130 drop seizures and 1 seizure-free day/month, France) to 0.83 (seizure-free, UK). In all surveys, seizure-free days had a greater impact on QoL than seizure frequency (P < 0.001). CONCLUSIONS: Fewer seizures and additional seizure-free days improved QoL in patients with LGS or DS; seizure-free days had the greatest impact on QoL.

Development of lacosamide for the treatment of partial-onset seizures.

Lacosamide is an antiepileptic drug (AED) available in multiple formulations that was first approved in 2008 as adjunctive therapy for partial-onset seizures (POS) in adults. Unlike traditional sodium channel blockers affecting fast inactivation, lacosamide selectively enhances sodium channel slow inactivation. This mechanism of action results in stabilization of hyperexcitable neuronal membranes, inhibition of neuronal firing, and reduction in long-term channel availability without affecting physiological function. Lacosamide has a well-characterized and favorable pharmacokinetic profile, including a fast absorption rate, minimal or no interaction with cytochrome P-450 izoenzymes, and a low potential for drug-drug interactions. Lacosamide clinical development included three placebo-controlled, double-blind, randomized trials conducted in more than 1300 patients, each demonstrating safety and efficacy of lacosamide compared to placebo as adjunctive therapy for adults with POS. The clinical use of lacosamide may broaden, pending results of trials evaluating its use as monotherapy for POS in adults, as treatment for epilepsy in pediatric subjects, and as adjunctive treatment for uncontrolled primary generalized tonic-clonic seizures in those with idiopathic generalized epilepsy.