Biosimilar Use Among 38 ASCO PracticeNET Practices, 2019-2021

Abstract

PURPOSE Biosimilars offer increased patient choice and potential cost-savings, compared with originator biologics. We studied 3 years of prescribed biologics among US physician practices to determine the relationship of practice type and payment source to oncology biosimilar use. METHODS We acquired biologic utilization data from 38 practices participating in PracticeNET. We focused on six biologics (bevacizumab, epoetin alfa, filgrastim, pegfilgrastim, rituximab, and trastuzumab) for the period from 2019 to 2021. We complemented our quantitative analysis with a survey of PracticeNET participants (prescribers and practice leaders) to reveal potential motivators and barriers to biosimilar use. We implemented logistic regression to evaluate the biosimilar use for each biologic, with covariates including time, practice type, and payment source, and accounted for clusters of practices. RESULTS Use of biosimilars increased over the 3-year period, reaching between 51% and 80% of administered doses by the fourth quarter of 2021, depending on the biologic. Biosimilar use varied by practice, with independent physician practices having higher use of biosimilars for epoetin alfa, filgrastim, rituximab, and trastuzumab. Compared with commercial health plans, Medicaid plans had lower biosimilar use for four biologics; traditional Medicare had lower use for five biologics. The average cost per dose decreased between 24% and 41%, dependent on the biologic. CONCLUSION Biosimilars have, through increased use, lowered the average cost per dose of the studied biologics. Biosimilar use differed by originator biologic, practice type, and payment source. There remains further opportunity for increases in biosimilar use among certain practices and payers.

Understanding interchangeable biosimilars at the federal and state levels

“…In the United States, biosimilar use in oncology increased up to 80%, depending on the biosimilar, from 2019 to 2021. 3 The increased uptake of biosimilars has already resulted in substantial savings to the US health care system; additional savings of approximately $181 billion during the next 5 years is anticipated as new biosimilars launch and adoption of existing biosimilars increases. 3,4 As biologics and their more affordable biosimilar versions become increasingly common in prescribing practices across therapeutic areas, health care providers need an enhanced understanding of these drugs.…”