- Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) within twice (2x) the upper limit of normal at screening and bilirubin within 1.25x ULN at screening. AST, ALT, alkaline phosphatase and bilirubin >2.0 xULN (isolated bilirubin >2.0xULN is acceptable if bilirubin is fractionated and direct bilirubin <35%).