ABSTRACT
I. INTRODUCTION Traditional first-line therapy for chronic lymphocytic leukemia (CLL) has been chloram bucil (CLB) with or without corticosteroids (1-15). Alternative alkylator-based regimens include cyclophosphamide (CTX) in combination with vincristine and prednisone (COP) (8,12,14,16-18); adriamycin and prednisone (CAP) (19-22); vincristine, adriamycin, and prednisone (CHOP) (13,20,23-24); CHOP with Ara-C (POACH) (25); melphalan and prednisone (CMP) (11), and others (26-28). In de novo CLL, alkylator regimens yield response rates of 60% to 80%, but with only a 10% to 25% rate of complete remission. Response rates in previously treated patients vary widely, ranging from 25% to 75%, but complete remissions were rarely achieved (Table 1). Recently, the nucleoside analogs fludarabine monophosphate (21,29-49), 2-chlorodeoxyadenosine (50-70), and deoxycoformycin (71-75), have demonstrated activity in previously treated patients with relapsed or alkylator-refractory disease (Tables 2-4). As observed with the alkylator regimens, response rates with nucleoside analogs are higher in previously untreated CLL than when administered in the salvage setting.
