Comparative Safety and Effectiveness of Bevacizumab Biosimilars to Originator for the Treatment of Metastatic Colorectal Cancer

Background: Ontario has publicly funded biosimilar bevacizumab for first-line metastatic colorectal cancer (mCRC) since 2019. Clinical trials demonstrate comparable efficacy and safety of bevacizumab biosimilars to originator bevacizumab. The objective of this study was to assess real-world safety and effectiveness of the implementation of bevacizumab biosimilars compared with originator bevacizumab in patients with mCRC. Methods: This was a population-based, retrospective study comparing Ontario patients starting treatment with bevacizumab biosimilars between August 12, 2019, and March 31, 2021, and starting treatment with originator bevacizumab between July 2, 2008, and August 11, 2019. Safety outcomes included death within 30 days of the last dose received, any hospitalization, direct hospitalization, and hospitalization resulting from bevacizumab-related toxicity, chemotherapy-related toxicity, and febrile neutropenia. Event rates were assessed using negative binomial and logistic regression. The effectiveness outcome was overall survival, calculated using Kaplan-Meier and Cox proportional hazards regression. A subgroup analysis compared safety and effectiveness outcomes between patients on bevacizumab biosimilar products and matched comparators. Results: We identified 8,996 patients who initiated first-line treatment of bevacizumab for mCRC. Accounting for duration of follow-up, no significant differences were observed in the rate of hospitalization between treatment groups. No differences in overall survival (log-rank P>.05) or hazard ratios (propensity score–matched hazard ratio, 1.03; 95% CI, 0.92–1.16) were observed in the crude and propensity score–matched cohorts. Subgroup analysis demonstrated similar safety and effectiveness patterns. Conclusions: The demonstrated similarity in safety and effectiveness between bevacizumab biosimilars and originator bevacizumab provides further support for the use of and confidence in biosimilar products.