Cost-Effectiveness Analysis of Bevacizumab Biosimilars Versus Originator Bevacizumab for Metastatic Colorectal Cancer: A Comparative Study Using Real-World Data.

Objectives: MVASI (Amgen) and Zirabev (Pfizer) are 2 of the earliest bevacizumab biosimilars approved for the first-line treatment of metastatic colorectal cancer (mCRC). We aimed to confirm and quantify the real-world cost savings and cost-effectiveness of MVASI and Zirabev relative to originator bevacizumab for patients with mCRC.

Methods: We conducted a population-based, retrospective cohort study in Ontario, Canada, where originator and biosimilar bevacizumab are universally publicly funded. All mCRC patients who received originator bevacizumab between January 2008 and August 2019 or biosimilar bevacizumab between August 2019 and March 2021 were propensity score matched (1:4) to adjust for baseline differences. Total 1-year patient-level costs (CAD) and effects (life years [LY] and quality-adjusted LYs) were calculated from the public health payer's perspective. Primary outcomes included incremental net monetary benefit and incremental net health benefit (INHB). Sensitivity analyses included a subgroup analysis by biosimilar type (MVASI/Zirabev) and a 2-year analysis.

Results: The matched cohort included 747 biosimilar cases and 2945 comparators. Bevacizumab biosimilars were associated with an incremental cost of -$6379 (95%CI: -9417, -3537) (ie, cost saving) and incremental effect of 0.0 (95% CI: -0.02, 0.02) LY and -0.01 (95% CI: -0.03, 0) quality-adjusted LYs gained. Incremental net monetary benefit and INHB estimates were $6331 (95% CI: 6245, 6417) and 0.127 LY (95% CI: 0.125, 0.128), respectively, at a willingness-to-pay threshold of $50 000/life year gained, with all estimates indicating the cost-effectiveness of biosimilar bevacizumab. Cost-effectiveness remained consistent across biosimilar brand subgroups and 2-year sensitivity analyses.

Conclusion: Bevacizumab biosimilars demonstrated real-world cost savings while providing similar survival benefit as originator bevacizumab, confirming the initial expectations of their implementation and supporting health system sustainability.