<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>An oral formulation of the phosphate salt of fludarabine, a synthetic purine nucleoside analogue antimetabolite with antineoplastic activity. Fudarabine is preferentially transported into malignant cells and metabolized by deoxycytidine kinase to its active form, 2-fluoro-ara-ATP; 2-fluoro-ara-ATP competes directly with deoxyadenosine triphosphate (dATP) and inhibits alpha DNA polymerase, RNA reductase, and DNA primase, which may result in inhibition of DNA synthesis and cell death.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>