Medicaid and Medicare Part B spending on immunomodulators and biosimilars

Introduction Prices for immunomodulators used in dermatological conditions are rising in the United States. While Medicare Part-D solely covers medication costs, Medicare Part-B covers outpatient infusion and injection costs given by medical professionals. We aim to analyze recent trends in Medicare Part-B spending on immunomodulators and their biosimilars used in the treatment of common chronic inflammatory dermatoses. Methods The 2012-2018 Medicare Part-B spending data on immunomodulators commonly used for dermatologic conditions were extracted from the Centers for Medicare and Medicaid Services database. Inflation was adjusted to reflect 2012-dollar amounts using the Consumer Price Index. Results Medicare Part-B spending has increased by 27.5% from 2012 to 2018 ($2.5B, $3.2B). Average annual total spending (AATS) is greatest for rituximab ($1,522,757,520), and average annual spending per maintenance dose (AASPMD) is greatest for ustekinumab-90 mg ($12,976). The percent change in AASPMD increased for all immunomodulators with Etanercept-50 mg having the greatest percent change (+64.6%, +$285.70). Infliximab had a greater AATS and AASPMD than its biosimilars. Discussion Medicare Part-B spending is often overlooked but plays a big role in federal healthcare spending. Exploring the strategic use of less expensive biosimilars could help mitigate spending.