Bevacizumab [rhuMAb-VEGF, anti-VEGF monoclonal antibody, Avastin™] is a humanised endothelial growth factor antagonist. It is undergoing development with Genentech in the USA for the treatment of relapsed metastatic breast cancer, and solid tumours, including advanced lung cancer. The FDA granted fast track status for bevacizumab, for the treatment of metastatic breast cancer, in April 2001.Clinical studies: the antibody is in phase I for diabetic retinopathy. It is thought to cut off the blood supply to tumours and prevent excess blood vessel growth at the retina in diabetic patients.Genentech announced in December 1999 that its phase II clinical trials of bevacizumab in combination with chemotherapy had met their primary objectives in colourectal and non-small cell lung cancer. A phase III trial in metastatic colourectal cancer is underway and compares the combination of bevacizumab + irinotecan + flourouracil/leucovorin with irinotecan + flourouracil/leucovorin and bevacizumab + flourouracil/leucovorin. A phase III trial in metastatic breast cancer is also underway in the US. Genentech is sponsoring the colorectal trial, and is in discussions with the NCI’s cooperative oncology group, ECOG regarding sponsorship for the proposed phase III lung cancer trial. Recruitment into the renal cancer trial was stopped in October 2001 because the NCI’s Data and Safety Monitoring Board determined that the trial had reached its pre-specified efficacy endpoint at the second interim analysis. A phase II/III trial is also underway which will evaluate bevacizumab in combination with carboplatin and paclitaxel, in patients with advanced non-squamous non-small cell lung cancer. is currently underway in the US, as is another phase II trial in patients with renal cancer.