Safety and Effectiveness of Bevacizumab Treatment for Metastatic Colorectal Cancer: Final Results from the Avastin® Registry – Investigation of Effectiveness and Safety (ARIES) Observational Cohort Study

Abstract Aims The Avastin ® Registry – Investigation of Effectiveness and Safety (ARIES) observational cohort study (OCS) was designed to prospectively examine outcomes associated with bevacizumab-containing treatment for metastatic colorectal cancer (mCRC) in a community-based setting, where patient populations are less restricted than those in randomised trials. Materials and Methods Patients with mCRC who were eligible for bevacizumab in combination with chemotherapy in first- or second-line treatment were enrolled from November 2006 to September 2008. There were no protocol-specified treatment regimens; the dose and schedule of bevacizumab and chemotherapy were at the treating physician's discretion. The objectives in the ARIES OCS included analyses of progression-free survival (PFS), overall survival, treatment patterns and safety in each of the first- and second-line treatment cohorts. Results ARIES enrolled 1550 patients with mCRC receiving first-line therapy with bevacizumab. The median follow-up time was 20.6 months. The median PFS in this cohort was 10.2 months (95% confidence interval 9.8–10.6) and the median overall survival was 23.2 months (95% confidence interval 21.2–24.8). In a separate cohort of 482 patients with second-line mCRC, the median follow-up time was 16.9 months, the median PFS and overall survival from the start of second-line treatment to the end of follow-up was 7.9 months (95% confidence interval 7.2–8.3) and 17.8 months (95% confidence interval 16.5–20.7), respectively. Incidences of known bevacizumab-associated adverse events in ARIES were generally consistent with those previously reported in OCSs and randomised trials. Conclusion Results from the prospective ARIES OCS add further evidence to support the effectiveness and safety of bevacizumab when added to first- and second-line treatment regimens for patients with mCRC in community treatment settings.