Bevacizumab in the first-line treatment of metastatic breast cancer

Bevacizumab plus paclitaxel has proven efficacy as first-line therapy for metastatic breast cancer based on the results of a randomised, phase III study (E2100). It has been recently reported that the addition of bevacizumab to paclitaxel doubled the median progression-free survival from 5.9 to 11.8 months (hazard ratio [HR] = 0.60, p< 0.0001). This benefit was corroborated in an analysis submitted to health authorities globally, using the intent-to-treat population; median progression-free survival of 5.8 increased to 11.4 months (HR = 0.42, p< 0.001), and confirmed by an independent review facility (5.8 vs. 11.3 months, HR = 0.48). This significant progression-free survival benefit was maintained across a number of patient subgroups, including those who had received prior adjuvant taxane chemotherapy. While there was no significant difference in overall survival, the addition of bevacizumab to paclitaxel increased the 1-year survival rate (81.2% vs. 73.4%, p = 0.01). As compared with bevacizumab use in other indications, no new safety signals were evident with the combination therapy, which was generally well tolerated. The only grade 3 and 4 toxicities that were increased by ≥5% with the addition of bevacizumab to paclitaxel were hypertension, sensory neuropathy, fatigue and neutropenia, the latter ones likely to be caused by the increased duration of paclitaxel treatment.