Cladribine

Cladribine is a nucleoside analog of deoxyadenosine and prodrug form of 2-chlorodeoxyadenosine triphosphate (2-CdATP).{62557} It is triphosphorylated to Cd-ATP by the successive actions of deoxycytidine kinase, nucleoside monophosphate kinase, and nucleoside diphosphate kinase. Cladribine is cytotoxic to resting or proliferating lymphocytes.{62558} It inhibits RNA synthesis and induces DNA strand breaks in resting human peripheral blood lymphocytes when used at concentrations of 1 and 10 µM.{21539} Cladribine induces cell cycle arrest at the G1 phase and apoptosis in U266, RPMI-8226, and MM.1S multiple myeloma cells in a concentration-dependent manner.{62559} It reduces tumor growth in HT-29 colon cancer, RL lymphoma, and RPMI-8226 multiple myeloma mouse xenograft models when administered at a dose of 12 mg/kg.{62560} Formulations containing cladribine have been used in the treatment of hairy cell leukemia.