2-Chlorodeoxyadenosine: a potent antimetabolite with major activity in the treatment of indolent lymphoproliferative disorders

2-Chlorodeoxyadenosine (2-CdA) is unique compared with traditional antimetabolites in that it is equally active against dividing and resting lymphocytes, which may be especially important in the treatment of indolent lymphoproliferative disorders because most cells in these disorders are in the resting phase. Significant clinical activity has been demonstrated for 2-CdA in the treatment of hairy cell leukemia, chronic lymphocytic leukemia, low-grade non-Hodgkin's lymphoma, Waldenström macroglobulinemia, and more recently prolymphocytic leukemia. More modest activity has been shown for 2-CdA in acute and chronic leukemias and in a variety of miscellaneous conditions, including Langerhans'-cell histiocytosis and multiple sclerosis.