Treatment of Hairy Cell Leukemia with Nucleoside Analogs

Hairy cell leukemia (HCL), or leukemic reticuloendotheliosis, is a rare chronic lymphoproliferative disorder first described in 1958. The majority of patients with HCL will require treatment at presentation or sometime during the course of their disease. 2&s;-Deoxycoformycin and 2-chlorodeoxyadenosine (2-CdA) are nucleoside analogs that induce long-lasting complete remissions in the majority of patients with HCL. The rarity of HCL underestimates the disease’s importance as the prototype lymphoproliferative disorder sensitive to biological response modifiers and the newer purine analogs. Fludarabine, although rigorously evaluated in patients with chronic lymphocytic leukemia, has only been evaluated in small numbers of patients with HCL. The clinical consequences of the severe and protracted immunosuppression that follows even single courses of 2-CdA will require close observation. The subcutaneous and oral routes of drug delivery remain to be tested in large numbers of patients with HCL and larger follow-up, but if successful would further simplify 2-CdA therapy and might reduce costs.