Issues for the future development of fludarabine phosphate

Fludara I.V. (fludarabine phosphate) is a purine analogue with a high level of activity in a variety of indolent lymphoproliferative malignancies, including chronic lymphocytic leukemia (CLL), low-grade non-Hodgkin's lymphomas (NHL), cutaneous T-cell lymphoma, macroglobulinemia, and hairy-cell leukemia. The high response rate in relapsed and refractory patients with CLL suggests that Fludara I.V. is the most active single agent for this condition. Nevertheless, a number of issues for the future development of Fludara I.V. must be considered: the optimal dose, schedule, and route of administration (intravenous v oral) remain to be determined. To improve on single-agent results, combinations of Fludara I.V. with other agents are under development for patients with CLL and NHL. Phase III clinical trials will be performed to compare Fludara I.V. with standard therapy versus the combination regimen in previously untreated patients with CLL. A similar study is under consideration for low-grade NHL. Companion immunologic and biologic studies will be an integral component of these trials to provide a more rational approach to staging and treatment, and to increase our knowledge of the biology of these disorders.