Cladribine in hairy cell leukemia

Cladribine is a purine nucleoside analog that has been applied extensively to the treatment of indolent lymphoid malignancies, especially hairy cell leukemia (HCL). It induces apoptosis of hairy cells, and, thereby, induces prolonged complete remissions in most patients. This article reviews the history, rationale, chemical structure, mechanism of action, clinical activity, and toxicity of cladribine in HCL. Salvage treatments, for relapse after cladribine, also are discussed.