6. have adequate hepatic function, defined as having a serum total bilirubin concentration ≤1.5mg/d, or ≤2 x the upper limit of normal (ULN) if associated with hepatobiliary metastases or Gilbert syndrome, and having serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations ≤2.5 × ULN, or ≤5 x ULN for patients with known hepatic metastases;