Budget impact analysis of antiepileptic drugs for Lennox-Gastaut syndrome
In October 2011, clobazam was FDA-approved for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS), a debilitating childhood epilepsy characterized by drop attacks, for patients 2 years and older. To assess the budget impact of adding clobazam to an antiepileptic drug (AED) portfolio containing topiramate, lamotrigine, and rufinamide in a hypothetical, 100,000-member commercially insured health plan. Patient characteristics and AED efficacy (decrease in drop-seizure frequency) were modeled with clinical data. Medical costs were derived from administrative claims data from a large U.S. managed health plan, with the assumption that 2.3% of drop seizures required medical care. Two-year budget impact was measured. Results were expressed as the overall difference in costs (medical and pharmacy) to a health plan and cost per member per month (PMPM) after addition of clobazam. Analyses of alternative scenarios were performed. With the assumption that 0.04% of the plan population had LGS, adding clobazam to the formulary resulted in cost savings of $98,059 in year 1 and $131,690 in year 2 (savings of $0.08 and $0.11 PMPM, respectively). Analyses of alternative scenarios with lower seizure rates upon discontinuation or greater long-term efficacy for lamotrigine and topiramate did not substantially alter conclusions. The assumption that fewer drop seizures required medical care resulted in a savings of approximately $5,000 per year with clobazam, which suggested that medically attended drop seizures drive costs. Medically attended drop seizures are a major cost driver for LGS patients. Adding clobazam to a health plan formulary can have a positive overall budget impact through decreased medical costs associated with drop seizures.