Potential cost-savings from the use of the biosimilars filgrastim, infliximab and insulin glargine in Canada: a retrospective analysis

Abstract Background In 2014 and 2015, biosimilars for the drugs filgrastim, infliximab, and insulin glargine were approved for use in Canada. The introduction of biosimilars in Canada could provide significant cost savings for the Canadian healthcare system over originator biologic drugs, however it is known that the use of biosimilars varies widely across the world. The aim of this study was to estimate the use of biosimilars in Canada and potential cost-savings from their use. Methods We performed a retrospective analysis of Canadian drug purchases for filgrastim, infliximab, and insulin glargine from July 2016 to June 2018. This was a cross-sectional study and the time horizon was limited to the study period. As a result, no discounting of effects over time was included. Canadian drugstore and hospital purchases data, obtained from IQVIA™, were used to estimate the costs per unit and unit volume for biosimilars and originator biologic drugs within each province. Potential cost-savings were calculated as a product of the units of reference originator product purchased and the cost difference between the originator biologic and its corresponding biosimilar. Results The purchase of biosimilars varied by each province in Canada, ranging from a low of 0.1% to a high of 81.6% of purchases. In total, $1,048,663,876 Canadian dollars in savings could have been realized with 100% use of biosimilars over the originator products during this 2 year time period. The potential savings are highest in the province of Ontario ($349 million); however, even in smaller markets (PEI and Newfoundland), $28 million could have potentially been saved. Infliximab accounted for the vast majority of the potential cost-savings, whereas the purchases of the biosimilar filgrastim outpaced that of the originator drug in some provinces. In sensitivity analyses assuming only 80% of originator units would be eligible for use as a biosimilar, $838 million dollars in cost savings over this two-year time period would still have been realized. Conclusions The overall use of biosimilar drugs in Canada is low. Policy makers, healthcare providers, and patients need to be informed of potential savings by increased use of biosimilars, particularly in an increasingly costly healthcare system.