Current Status of U.S. Clinical Trials in Chronic Lymphocytic Leukemia

Current therapies for chronic lymphocytic leukemia (CLL) have not substantially improved the survival of these patients (pts). As a result treatment has been primarily palliative. One major obstacle in designing innovative therapies has been a lack of new and effective agents. Recent interest in clinical trials has been stimulated by the impressive activity in pts with CLL of three unique purine analogues; fludarabine (FLUDARA), 2′-deoxycoformycin (DCF) and 2-chlorodeoxyadenosine (CDA). Of the three, the largest experience in CLL is with FLUDARA. More than 1200 CLL patients have received FLUDARA either on clinical trials or through the NCI-Group C protocol mechanism. In contrast to the published data, preliminary analysis of the first 87 evaluable Group-C patients revealed only 2% complete and 37% partial responses; this discrepancy can be explained by the fact that most patients were still receiving treatment at the time of the analysis, and many were continuing to respond (9 of 12 patients who received ...