Bevacizumab: in first-line treatment of metastatic breast cancer

Bevacizumab, a recombinant humanised monoclonal antibody against vascular endothelial growth factor, is approved in Europe as first-line therapy for metastatic breast cancer (mBC) and metastatic carcinoma of the colon or rectum (mCRC); the European Medicines Agency gave a positive opinion recommending its use in non-small-cell lung cancer (NSCLC) and is also considering other indications. In the US, it is licensed for use for mCRC and NSCLC, with its use as first-line treatment in mBC under review by the US FDA. In the pivotal E2100 trial in >700 previously untreated patients with locally recurrent or mBC, recipients of bevacizumab plus paclitaxel had a statistically and clinically significant increase in progression-free survival versus paclitaxel recipients (13.3 vs 6.7 months; hazard ratio 0.48; p < 0.001) [primary endpoint]. There was also a >2-fold higher objective response rate in the bevacizumab plus paclitaxel arm than in the paclitaxel arm; the between-group difference in median overall survival did not reach statistical significance (25.7 vs 23.8 months). Bevacizumab had an acceptable tolerability profile in these patients, with the majority of adverse events being generally mild to moderate in severity. There are targeted adverse events, including gastrointestinal perforations, wound healing complications and haemorrhage, which although they occur infrequently (incidence <=2%), are potentially life-threatening and may cause morbidity.