Abstract
OBJECTIVES: This study examined the drug formulary coverage, usage restrictions (i.e. prior authorization, step therapy and quantity limits), and cost-sharing rates of biologic disease modifying anti-rheumatic drugs (DMARDs) in Medicare Part D in the period 2006 to 2015. METHODS: Study data were derived from the Centers for Medicare and Medicaid Services (CMS) Medicare Prescription Drug Plan Formulary and Pharmacy Network Files data. National Drug Codes (NDCs) information was derived from the U.S. Food and Drug Administration (FDA) NDC Directory. Descriptive statistics were performed. RESULTS: The FDA approved 10 biologic DMARDs in the period 2006 to 2015. In 2006, the mean percentage of Medicare Part D formularies covering all biologic DMARDs was 74.5%. The Medicare Part D prescription drug coverage reached its highest level (85.9%) in 2007 and it went down to 73.8% in December 2015. The percentage of formularies requiring prior authorization across biologic DMARDs ranged from 68.4% in 2006 to 93.1% in 2014. The use of step therapy varied by drug. No formularies required step therapy for adalimumab and rituximab; whereas, over 10% of formularies required step therapy for certolizumab, golimumab, tocilizumab, abatacept, tofacitinib, and etanercept in 2015. The percentage of formularies requiring quantity limits ranged from 0.0% (rituximab) to 47.4% (tofacitinib) in 2015. Placement in tier 5 increased from 7.9% in 2006 to 61.5% in 2015. Placement in tiers 2-4 decreased during the study period. Coinsurance was the most commonly used type of cost-sharing mechanisms; it was required by 62.3% of the plans in 2006 and 68.4% in 2015. CONCLUSIONS: All Medicare Part D formularies covered at least one biologic DMARD during the period 2006-2015. The large majority of formularies placed prior authorization, step therapy and quantity limits on the utilization of biologic DMARDs. In addition, biologic DMARDs were increasingly placed in higher specialty tiers that required high cost-sharing rates. communication was significantly associated with a decrease in anti-TNF utilization (p<0.001). In addition, the FDA anti-TNF safety communication was significantly associated with an increase in the utilization of non-anti-TNF (p<0.001). CONCLUSIONS: The utilization of biologic DMARDS in the Medicaid outpatient pharmacy program significantly changed over time. The utilization of biologic DMARDS was higher post- enactment of the ACA compared to the period pre-ACA. Likewise, the utilization of Anti-TNF biologies significantly increased after the implementation of the ACA and decrease following the 2011 FDA safety communication.