Effectiveness of bevacizumab added to standard chemotherapy in metastatic colorectal cancer: final results for first-line treatment from the ITACa randomized clinical trial

Background: We report the results from a first-line phase III randomized clinical trial on metastatic colorectal cancer (mCRC) aimed at evaluating the effectiveness of adding bevacizumab (B) to standard first-line chemotherapy (CT). Patients and methods: mCRC patients were randomized to receive first-line CT (FOLFIRI or FOLFOX4) plus B (arm A) or CT only (arm B). The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), response rate (ORR) and safety. Three hundred and fifty patients and 310 events were required to have an 80% statistical power to detect a difference in PFS between the groups. Results: Between November 2007 and March 2012, 376 patients were randomized. About 60% of patients received FOLFOX4 and 40% FOLFIRI. After a median follow-up of 36 months, 343 progressions and 275 deaths had been observed in the overall population. The median PFS was 9.6 [95% confidence interval (CI) 8.2-10.3] and 8.4 (95% CI 7.2-9.0) months for arms A and B, respectively, with a hazard ratio of 0.86 (95% CI 0.70-1.07; P = 0.182). No statistically significant differences in OS or ORR were observed. B-containing regimens were associated with more frequent hypertension, bleeding, proteinuria and asthenia. Conclusions: The addition of B to standard first-line CT for mCRC did not provide a benefit in terms of PFS, OS or ORR. Further research is warranted to better identify the target population.