Utilization management for Medicare Part D oral oncology drugs increased between 2010 and 2020, according to a study of formulary files. “Prior authorization was the most prevalent strategy for specialty brand and generic drugs, as well as nonspecialty brand drugs,” the authors conclude. “Quantity limit use increased and was the most common strategy for nonspecialty generic drugs.”
Investigators used the 2010-2020 Medicare Part D formulary files to identify the use of prior authorization, quantity limits, and step therapy for each unique drug-dose-formulary combination of orally administered oncology drugs. Medicare categorized the agents as specialty (monthly cost above $600 in 2010-2016 and $670 in 2017-2020) or nonspecialty and brand or generic.
The number of Medicare Part D beneficiaries increased from 28 million in 2010 to 47 million in 2020. The number of formularies climbed from 333 to 548, and the number of oral oncology drugs quadrupled from 62 to 249. “Unique drug-dose-formulary prescribing combinations increased from 19,004 to 122,173 between 2010 and 2020,” the authors write. “The proportion of drug-dose-formulary combinations requiring prior authorization increased over time. For specialty brand drugs, the proportion increased from 72.8% to 95.4% between 2010 and 2020. Specialty generic drugs entered the market in 2016; prior authorization use increased from 91.1% in 2016 to 95.0% in 2020. For nonspecialty brand drugs, the proportion of drug-dose-formulary combinations requiring prior authorization increased from 15.9% to 78.2% and for nonspecialty generic drugs from 1.0% to 8.0% between 2010 and 2020.”
The use of quantity limits for specialty brand drugs doubled from 31.4% to 62.5% over the study period. “For specialty generic drugs, the proportion increased from 32.7% to 77.8% between 2016 and 2020,” the authors write. “For nonspecialty brand drugs, the proportion with quantity limits increased from 11.8% to 47.3% and for nonspecialty generic drugs from 9.7% to 18.8% between 2010 and 2020.”