Current status and future directions of clinical trials in chronic lymphocytic leukemia.

Standard therapy for chronic lymphocytic leukemia has been an alkylating agent plus a corticosteroid, a palliative approach. But now, because of sophisticated cytogenetic and biologic evaluation of CLL patients leading to more accurate staging, plus interest in two new chemotherapy agents, 2'-deoxycoformycin and fludarabine monophosphate, different approaches to the therapy of CLL are being studied. These include combination chemotherapy programs, incorporating the new drugs with standard therapy, combining them with each other, and investigating novel biological agents. While no treatment has clearly altered the outcome of patients with CLL, clinical trials of patients without prior therapy, using new standardized criteria for response, are needed.