This multicenter study will randomize patients to one of three treatment arms. The purpose of this study is to evaluate the effectiveness and safety of multiple administrations of rhuMAb VEGF when combined with chemotherapy for the treatment of metastatic colorectal cancer. Patients receive treatment weekly for 6 or 8 weeks, and may continue treatment until their disease progresses or they receive up to a total of 12 or 16 cycles of chemotherapy, depending on their treatment assignment. Blood samples will be collected for research purposes. VEGF is a potent growth factor and is a crucial regulator in the development of new blood vessels.
Standard chemotherapy is added to directly attack tumor cells.
Inclusion Criteria 1. Patients must be at least 18 years old. Patients must have confirmed colorectal cancer with evidence of metastases. Patients must have measurable disease. Patients must have an excellent performance status.