LAUSR

Dupilumab is a monoclonal antibody that inhibits the action of interleukin-4 and interleukin-13. Since FDA approval in 2017, dupilumab has revolutionized the treatment of moderate-tosevere atopic dermatitis (AD) and has gained approval for additional indications. Few studies have examined geographic trends in its adoption in the Medicare population and none have described temporal trends (1). Characterizing such trends is important given that access to biologics and dermatologic care for AD are geographically variable, with rural areas often experiencing decreased access and utilization (2,3). Identifying temporal trends, therefore, may be useful in detecting widening disparities and considering interventions to improve access. Our study may also be helpful in understanding the impact of recently expanded dupilumab indications on prescription patterns. Prescribers, beneficiaries, and costs of dupilumab prescriptions were obtained from publicly available Centers for Medicare and Medicaid Services (CMS) Medicare Provider Utilization and Payment Data: Part D (4). Prescriber-level and geographic trends were analyzed for prescribers who submitted 10 claims annually. Counties were assigned a Rural-Urban Continuum Code (RUCC) based on the National Center for Health Statistics Urban-Rural Classification Scheme for Counties and categorized into metro (RUCC 1–3) or non-metro (RUCC 4–9). As of 2019, there were 7944 prescribers of dupilumab, representing more than a five-fold increase since 2017 (Table 1). The mean claims per prescriber nearly doubled, resulting in a nearly 10-fold increase in total dupilumab claims. Total drug cost increased proportionally to claims.