Presenters: Bonnie A. Labdi, PharmD, BCOP, The Craneware Group; Rebecca L. Attridge, PharmD, MSc, BCPS, BCCCP, The Craneware Group, Deerfield Beach, FL
Co-Authors: Michelle Winkler, PhD, MPH, The Craneware Group; Alec Gilster, BS, The Craneware Group; Samuel G. Johnson, PharmD, BCPS, FCCP, The Craneware Group, Deerfield Beach, FL
BACKGROUND: Biosimilars have significantly changed the landscape of oncology care in the United States. As of September 30, 2022, 39 biosimilars have been FDA-approved, with several others in various stages of development. This study analyzed real-world data over 3.5 years of a bevacizumab originator drug and biosimilar bevacizumab for on- and off-label oncology indications.
OBJECTIVES: The primary objective was to evaluate the use of a bevacizumab originator versus biosimilar drugs for oncology indications. The secondary objectives included evaluating the on- versus off-label use for oncology indications, the treatment setting, and the annual and quarterly trends.
METHOD: Deidentified real-world dispensations of a bevacizumab originator (Avastin) and biosimilars (bevacizumab-bvzr [Zirabev] and bevacizumab-awwb [Mvasi]) between January 1, 2019, and June 30, 2022, were extracted using Trisus Medication Compare (The Craneware Group; Deerfield Beach, FL). The patients were matched based on ICD-10 diagnosis codes, excluding patients with a nononcology diagnosis or those receiving an originator and a biosimilar. Significance tests were performed for continuous and categorical characteristics using Kruskal-Wallis and chi-square tests, respectively.
RESULTS: In total, 10,840 encounters over a 3.5-year time period (bevacizumab, N = 8523; biosimilars, N = 2317) were identified. Bevacizumab accounted for a higher total use (78.6%) than biosimilars (21.4%). A higher proportion of off-label use was seen with the originator drug versus the biosimilar drugs, whereas a higher proportion of on-label use was seen with biosimilars (off-label use, 5.3% vs 4.1%, respectively; on-label use, 94.7% vs 95.9%, respectively; P = .02). The most common on-label indications in both groups were colorectal cancer (46.9% vs 41.8%, respectively); ovarian, fallopian tube, or primary peritoneal cancer (27.6% vs 28.2%, respectively); and glioblastoma (10.7% vs 9.8%, respectively). Off-label use accounted for only 5.1% of dispensations, with the most common indication being endometrial cancer (3.5% vs 3.9%, respectively). The use of the originator drug and the biosimilar was higher in urban and outpatient settings than in rural and inpatient settings (P = .02 vs P = .04, respectively). Nonacademic settings showed higher biosimilar adoption than academic settings (51.8% vs 48.2%, respectively; P = .0005). Overall, the annual trends from 2019 to 2022 show that the use of the bevacizumab originator steadily decreased, from 99.9% to 27.3%, whereas biosimilar use steadily increased, from 0.1% to 72.7%.
CONCLUSION: This large real-world analysis showed that bevacizumab biosimilar use for on- and off-label indications increased substantially over time. Mvasi, although approved in April 2017, was not launched until July 2019, and Zirabev was unavailable until December 2019, accounting for low biosimilar use in 2019 and early 2020. Decreases in the originator drug and biosimilar drug use dropped in late 2020, which may be attributed to the COVID-19 pandemic.
- US Food and Drug Administration. FDA-approved biosimilar products. September 28, 2022. www.fda.gov/drugs/biosimilars/biosimilar-product-information. Accessed October 4, 2022.