Capecitabine (Xeloda) and irinotecan (CPT-11, Camptosar) exhibit single-agent activity in colorectal cancer, have nonoverlapping major toxicities, and exhibit a synergistic effect in tumor xenograft models. European early-phase trials of the combination in patients with metastatic colorectal cancer indicate good response rates across doses tested and manageable toxicities, with available data supporting use of a regimen of oral capecitabine at 1,000 mg/m2 twice daily on days 1 to 14 plus IV i...