BACKGROUND: We previously published an early report of a randomized, multicentertrial on the efficacy and toxicity of cladribine (2-CdA) + prednisone (P) compared with chlorambucil(Chl) + P in previously untreated patients with progressive or symptomatic chronic lymphocytic leukemia.Here we present the final report of this study. MATERIAL/METHODS: Of 229 patients, 126 received 2-CdA+Pand 103 Chl+P. Patients with no response or progression after three courses or who relapsed earlier than12 months after completing one treatment were switched to the other. Patients who relapsed later wereretreated with the same schedule as before. RESULTS: Thirty-three patients were retreated with 2-CdA+Pand 19 with Chl+P. Overall response (and complete response) rates were 35% (6%) and 47% (16%), respectively.In 50 patients initially treated with Chl+P and then with 2-CdA+P, complete response (CR) was achievedin 12 (24%) and overall response (OR) in 32 (64%). In 28 patients originally treated with 2-CdA+P andthen with Chl+P, CR in 1 (3%, p=0.01) and OR in 6 (21%, p=0.003) were obtained. We found no statisticallysignificant difference in overall survival time in patients treated initially with 2-CdA+P and Chl+Paged 60 years (4.63 and 5.27 years, respectively, p=0.45), 60-70 years (3.29 and 3.14 years, p=0.79),and >70 years (1.53 and 1.93 years, p=0.11). CONCLUSIONS: 2-CdA+P is significantly more effective asa second-line treatment and re-treatment than Chl+P. However, we found a trend to longer survival inelderly patients treated with Chl+P.

Keywords: Cladribine - administration & dosage, Chlorambucil - administration & dosage, Antineoplastic Combined Chemotherapy Protocols - therapeutic use, Cyclophosphamide - administration & dosage, Doxorubicin - administration & dosage, Leukemia, Lymphocytic, Chronic, B-Cell - drug therapy, Prednisone - administration & dosage, Vincristine - administration & dosage