A real-world analysis of factors associated with high healthcare resource utilization and costs in patients with myasthenia gravis receiving second-line treatment.

Despite current treatments, patients with myasthenia gravis (MG) experience unpredictable and inadequately controlled symptoms, lending to variability in the clinical and economic burden of disease. However, limited data are available on MG healthcare costs, and specifically, no data on patients initiating second-line therapy. Using claims data from the IBM® MarketScan® database, we assessed patient characteristics, healthcare resource utilization, and costs among MG patients initiating second-line therapy, and identified potential factors associated with high healthcare costs over a two-year follow-up period. We identified 1498 patients, of whom 49% and 31% received chronic steroids and non-steroidal immunosuppressants (NSISTs) as their second-line therapy, respectively. During follow-up, 49% experienced ≥1 MG exacerbation. Among all patients, mean all-cause total healthcare cost was $106,821 per patient during follow-up, with $88,040 and $18,780 attributed to medical and pharmacy costs, respectively. In a multivariable analysis, variables significantly associated with high cost included use of high-dose steroids, chronic intravenous immunoglobulin (IVIg, ≥6 cycles), and 1 and ≥ 4 (but not 2-3) MG exacerbations in the first year after second-line therapy initiation. Any number of exacerbations were associated with high cost in a univariable analysis. A stratified cost analysis showed that patients with >1 exacerbation, ≥1 treatment switch, and high-dose steroid use in this first year experienced $198,487, $114,037, and $79,752 mean MG-related total healthcare spend during follow-up, respectively. These data suggest that patients receiving chronic IVIg or NSISTs for MG experience significant economic burden. Disease characteristics including exacerbation and treatment history may be an indicator of future high costs.