6. Within 14 days of the first dose of study drug, patients must have adequate organ and marrow function as defined below: Absolute neutrophil count >/= 1,500/uL, Platelets >/= 100,000/uL, Hgb > 9.0 g/dL (may be transfused or receive epoetin alfa [e.g., Epogen®] to maintain or exceed this level), Total bilirubin </= 1.5 mg/dl, Serum creatinine </= 1.5 times the upper limit of normal or estimated CrCl >40mL/min, AST (SGOT) and/or ALT (SGPT) </= 2.5 X institutional upper limit of normal for patients without evidence of liver metastases, AST (SGOT) and/or ALT (SGPT) </= 5 X institutional upper limit of normal for patients with documented liver metastases.