Lacosamide as a first-line treatment option in focal epilepsy: a cost-utility analysis for the Greek healthcare system

Background and aims: Epilepsy is the most common serious neurological disorder worldwide. Approximately 40% of patients with focal epileptic seizures remain uncontrolled with antiepileptic drug (AED) monotherapy or polytherapy. Lacosamide has been recently approved by the European Medicines Agency as monotherapy for the treatment of focal seizures. The aim of this study was to estimate the cost-effectiveness of lacosamide compared with zonisamide as first-line treatment of focal epilepsy in patients with epilepsy aged >= 16 years to inform clinical decision-making in Greece. Methods: A discrete event simulation model was adapted to reflect treatment pathways and resource use within the Greek national healthcare system, as specified by clinical experts. The model captures time-varying events and patient characteristics. Clinical inputs were sourced from pivotal trials and a network meta-analysis comparing lacosamide with other AEDs. The model predicts disease progression and seizures, relevant and most common adverse events, withdrawal due to lack of efficacy or adverse events, and epilepsy-specific and all-cause mortality over a 2-year time horizon. Unit costs were retrieved from published Greek sources. Health outcomes were measured as quality-adjusted life years (QALYs); secondary outcome was the cost per seizure avoided. Robustness of the results was tested with univariate and probabilistic sensitivity analyses. Results: The lacosamide treatment pathway was associated with higher costs (i.e. euro1,064) and an additional 0.119 QALYs when compared with zonisamide, resulting in an incremental cost-effectiveness ratio of euro8,938 per QALY gained. The sensitivity analyses demonstrated that the results are most sensitive to the efficacy and utility estimates. Limitations: There are a number of limitations which stem from the process of model adaptation and lack of local real-world evidence. Conclusions: Lacosamide is a cost-effective option at a willingness-to-pay threshold of euro30,000 per QALY, representing a valuable monotherapy treatment option for patients with focal epileptic seizures in the Greek setting.