A Study of Avastin (Bevacizumab) in Combination With XELOX or FOLFOX-4 in Patients With Metastatic Colorectal Cancer.

This 2 arm study will compare the pharmacokinetics and safety of Avastin at steady state under 2 different dosing regimens, in combination with XELOX (oxaliplatin + Xeloda) or FOLFOX-4 (oxaliplatin, leucovorin and 5-fluorouracil). Patients randomized to the XELOX arm will receive Avastin (7.5mg/kg iv) on Day 1 of each 3 week cycle; patients randomized to the FOLFOX-4 arm will receive Avastin (5mg/kg iv) on Day 1 of each 2 week cycle. The anticipated time on study treatment is 3-12 months, and the target sample size is <100 individuals.