The cost effectiveness of rufinamide in the treatment of Lennox-Gastaut syndrome in the UK

Abstract

Lennox-Gastaut syndrome (LGS) is a catastrophic childhood form of epilepsy. The syndrome is characterized by mental impairment, frequent seizures of multiple types that are particularly resistant to treatment, and high rates of seizure-related injury. With the introduction of newer, but more costly, antiepileptic drugs (AEDs), it is important that decision makers are able to assess their value in the management of this rare and difficult-to-treat condition. To evaluate the cost effectiveness, from the UK NHS perspective, of rufinamide in patients with LGS. An individual patient-simulation model was developed to estimate the total treatment-related costs and clinical benefits of rufinamide compared with topiramate and lamotrigine over a 3-year time horizon. The model examines the treatment scenarios of adding rufinamide, lamotrigine or topiramate to older AEDs (standard therapy), or standard therapy alone within a primary-care or community setting. Three placebo-controlled clinical trials of adjunctive AED treatment for children with LGS were analysed. There are no head-to-head comparator studies. Between 98 and 139 patients were randomized in each study and the mean age in each study was 10, 11 and 14 years. A mixed-treatment comparison using a random-effects model was carried out on the number of patients in each response category, using the placebo arms of the respective trials. The primary outcome measure was the percentage of successfully treated patients, defined as >50% reduction in the frequency of total seizures and drop attacks. The hypothesis being tested was formulated after data collection. Costs ( pound, year 2006/07 values) of patient monitoring, switching treatments, hospitalization due to seizure, treatment of adverse effects, and personal and social services were included in the analysis. Results of 10,000 Monte Carlo simulations were bootstrapped to conduct probabilistic sensitivity analysis. Over 3 years, adjunctive rufinamide resulted in higher total costs than topiramate and lamotrigine; however, with more patients being treated successfully, this leads to acceptable incremental cost-effectiveness ratios. If society is prepared to pay at least 250 pounds for a 1% increase in the number of successfully treated LGS patients, in terms of a 50% reduction in the frequency of drop attacks, the probability of the treatment with rufinamide being cost effective is >80%. This cost-effectiveness analysis suggests that rufinamide results in more LGS patients being treated successfully at a reasonable cost from a UK NHS perspective.