Effectiveness and Costs Associated to Adding Cetuximab or Bevacizumab to Chemotherapy as Initial Treatment in Metastatic Colorectal Cancer: Results from the Observational FABIO Project.

Evidence available on the effectiveness and costs of biological therapies for the initial treatment of metastatic colorectal cancer (mCRC) is scarce and contrasting. We conducted a population-based cohort investigation for assessing overall survival and costs associated with their use in a real-world setting. Healthcare utilization databases were used to select patients newly diagnosed with mCRC between 2010 and 2016. Those initially treated with biological therapy (bevacizumab or cetuximab) added to chemotherapy were propensity-score-matched to those treated with standard chemotherapy alone, and were followed up to June 30th, 2018. Kaplan-Meier survival estimates, restricted mean survival time (RMST) and cumulative costs were compared between the two treatment arms. The study cohort included 1896 mCRC patients treated with biological therapy matched to 5678 patients treated with chemotherapy alone. Median overall survival was 21.8 and 20.2 months, respectively. After 84 months of follow-up, RMSTs were 30.9 and 31.9 months (p = 0.193), indicating no differences between the average survival time between treatment arms. Patients treated with biological therapy were associated with higher costs. Cumulative per capita costs were €59,663 and €44,399, respectively. In our study, first-line biological therapy did not improve long-term overall survival and was associated with higher costs as compared to standard chemotherapy.