BACKGROUND: Biological drugs as specialty medications have been a significant driver of drug expenditures for payers. Biologic disease-modifying antirheumatic drugs (DMARDs) are effective but costly treatments as payer’s perspective. Over the past two decades, Medicaid has been the primary public payer for DMARDs.

OBJECTIVES: To describe and analyze trends in the utilization, spending, and average per prescription cost of DMARDs individually, in subgroups, and overall, in the Medicaid-covered population.

METHODS: A retrospective, descriptive analysis was performed for 1991- 2021 using the publicly available national Summary Files from the Medicaid State Drug Utilization Data maintained by the Centers for Medicare & Medicaid Services. Annual prescription counts and reimbursement amounts were calculated for all brand-name and generic DMARDs, such as methotrexate, etanercept (Enbrel®), infliximab (Remicade®), adalimumab (Humira®), certolizumab pegol (Cimzia®), golimumab (Simponi®). Average per-prescription spending as a proxy for drug price was measured by dividing reimbursement by the number of prescriptions.

RESULTS: Prescriptions for DMARDs among Medicaid beneficiaries increased from 94 thousand in 1991 to over 3.5 million in 2019. Expenditures rose from $5 million in 1991 to over $16 billion in 2021. Over 23 years, the average per-prescription price of methotrexate, a nonbiologic DMARDs, dropped nearly 50%; however, the average per-prescription price of methotrexate brands (like Trexall) increased by almost three folds. In addition, the average per-prescription price of some essential biologic DMARDs like adalimumab increased by 1140% from 2003 to 2021.

CONCLUSIONS: A considerable rise in the number of Medicaid beneficiaries for DMARDs, more than 20 times over this study period, suggests an extraordinary increase in the utilization of DMARDs. Moreover, Medicaid expenditures on nonbiologic and biologic DMARDs rose (in current dollars) to over $16 billion in 2021. Introducing new biologic and nonbiologic DMARDs into the market in the past few years is eroding the market share for several established drugs.