GPT and Hepatic failure: However, during extended safety and tolerability monitoring in cycle 2, significant hepatic toxicities were identified and considered related to study treatment: a grade 5 hepatic failure (50 days after the last dose) in 1 patient receiving 0.19 mg/kg, and a grade 4 hepatic failure (with elevations of ALT, AST, and bilirubin) in 1 patient dosed with 0.25 mg/kg.