We are excited to share this three-province cost-effectiveness analysis of bevacizumab with first line combination chemotherapy in patients with metastatic colorectal cancer.
View the full text at https://journals.sagepub.com/doi/full/10.1177/23814683211021060
Authors: Reka E. Pataky , Jaclyn Beca , David Tran, Wei Fang Dai, Erind Dvorani, Wanrudee Isaranuwatchai, Stuart Peacock, Riaz Alvi, Winson Y. Cheung, Craig C. Earle, Scott Gavura, and Kelvin K. W. Chan
Background. Real-world evidence can be a valuable tool when clinical trial data are incomplete or uncertain. Bevacizumab
was adopted as first-line therapy for metastatic colorectal cancer (mCRC) based on significant survival
improvements in initial clinical trials; however, survival benefit diminished in subsequent analyses. Consequently,
there is uncertainty surrounding the cost-effectiveness of bevacizumab therapy achieved in practice. Objective. To
assess real-world cost-effectiveness of first-line bevacizumab with irinotecan-based chemotherapy versus irinotecan-based chemotherapy alone for mCRC in British Columbia (BC), Saskatchewan, and Ontario, Canada. Methods.
Using provincial cancer registries and linked administrative databases, we identified mCRC patients who initiated
publicly funded irinotecan-based chemotherapy, with or without bevacizumab, in 2000 to 2015. We compared
bevacizumab-treated patients to historical controls (treated before bevacizumab funding) and contemporaneous controls
(receiving chemotherapy without bevacizumab), using inverse-probability-of-treatment weighting with propensity
scores to balance baseline covariates. We calculated incremental cost-effectiveness ratios (ICER) using 5-year
cost and survival adjusted for censoring, with bootstrapping to characterize uncertainty. We also conducted one-way
sensitivity analysis for key drivers of cost-effectiveness. Results. The cohorts included 12,112 (Ontario), 1,161 (Saskatchewan), and 2,977 (BC) patients. Bevacizumab significantly increased treatment costs, with mean ICERs
between $78,000 and $84,000/LYG (life-year gained) in the contemporaneous comparisons and $75,000 and
$101,000/LYG in the historical comparisons. Reducing the cost of bevacizumab by 50% brought ICERs in all comparisons
below $61,000/LYG. Limitations. Residual confounding in observational data may bias results, while the
use of original list prices overestimates current bevacizumab cost. Conclusion. The addition of bevacizumab to
irinotecan-based chemotherapy extended survival for mCRC patients but at significant cost. At original list prices
bevacizumab can only be considered cost-effective with certainty at a willingness-to-pay threshold over $100,000/
LYG, but price reductions or discounts have a significant impact on cost-effectiveness.