Perspectives on purine analogues.

The purine analogs, fludarabine, 2-chlorodeoxy-adenosine, and 2'-deoxycoformycin, have revolutionized our approach to the treatment of a variety of indolent lymphoid malignancies. Because of their impressive single agent activity, they should be considered as an initial therapeutic option, not only for hairy cell leukemia, but also for chronic lymphocytic leukemia, indolent non-Hodgkin's lymphomas, and Waldenström's macroglobulenemia. Combinations of purine analogs with alkylatng agents, topisomerase II inhibitors, and other new compounds are in development, and their role as radiation sensitizers is being explored in clinical trials. Substantial activity has also been noted in several of the rheumatologic and immunologic disorders, and in multiple sclerosis. Continued progress requires innovative strategies which can modulate the biology and immunology of these diseases toward the goal of curing these patients.