Analysis of real-world trends of biosimilar prescribing from 2019 to 2020 indicated rapid uptake of biosimilars among oncology providers, although the extent of biosimilar prescribing varied among products.
In the United States, several biosimilars for the major oncology drugs bevacizumab, trastuzumab, and rituximab are approved and currently available in the market. To determine the real-world uptake of biosimilars among oncology providers, analysis of biosimilar prescribing behavior was conducted from 2019 to 2020. Data sources for this analysis included 2020 prescription data (Wolters Kluwer, n = 30,836), sales data (IQVIA), and dosage data (FDA Purple Book) between 2019 and 2021 (ION Solutions, n = 69,884).
In 2020, biosimilars for bevacizumab, trastuzumab, and rituximab accounted for 8.2% of new prescriptions. In 2019, in the 3 months following the launch of trastuzumab’s first biosimilar (trastuzumab-anns), the biosimilar was prescribed in 7.3% more patients than trastuzumab reference. In 2020, trastuzumab biosimilars were prescribed for 80.5% of initiating first-line trastuzumab patients. However, the uptake was lower for rituximab, with the first rituximab biosimilar (rituximab-pvvr) prescribed in 2.3% of cases. Switching to biosimilars was higher for trastuzumab, with 18.2% of patients switching to trastuzumab-anns in the first 90 days postlaunch.
In terms of drug pricing, biosimilars cost significantly less than their reference products; the cost per prescription was –42.0% for trastuzumab reference product, –29.9% for rituximab reference product, and –89.5% for bevacizumab reference product. However, the biosimilar launches or the lower price of biosimilars had little impact on reference product pricing. For all 3 reference products, the 2019 to 2020 year-over-year differences in price per prescription were comparable to the year-over-year averages in previous years (2015-2019).
Based on the findings of this analysis on biosimilar prescribing patterns between 2019 and 2020, the authors concluded that the uptake of biosimilars among oncology providers was rapid, although the extent of biosimilar prescribing varied among products.
Source: McGlynn KA, McGarry J, Patel KB, Clinton N. Real-world trends in biosimilar prescribing among oncology providers, 2019-2021. J Clin Oncol. 2021;39(suppl_15):e18701.
