- Adequate hepatobiliary function, as defined by the following baseline liver function tests: total serum bilirubin 1.5 upper normal limit (UNL); alanine amino transferase (ALT), aspartate amino transferase (AST) 2.5xUNL; alkaline phosphatase (AP) 2.5xUNL; if total alkaline phosphatase (AP) > 2.5xUNL, alkaline phosphatase liver fraction must be 2.5xUNL