High dose chlorambucil versus Binet's modified cyclophosphamide, doxorubicin, vincristine, and prednisone regimen in the treatment of patients with advanced B-cell chronic lymphocytic leukemia

Abstract

In recent years, much attention has been paid to the possible efficacy of intensive chemotherapy in the treatment of advanced, progressive B-cell chronic lymphocytic leukemia (CLL) patients. For this reason, the International Society for Chemo-Immunotherapy, Chronic Lymphocytic Leukemia Cooperative Group, has begun a randomized multicenter trial comparing Binet's modified cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) regimen with continuous high dose chlorambucil (HD-CLB). During the period January 1987 to May 1993, 228 previously untreated CLL patients from 7 cooperative institutions were randomized to this trial. Advanced and/or progressive disease was defined by high Total Tumor Mass (TTM) score (> 9), and/or short doubling time (DT) (< 12 months), and/or bone marrow failure. The response to therapy was defined by reduction of the initial TTM score. The end points of the trial were response rate, survival, and toxicity. HD-CLB resulted in a higher response rate than CHOP in evaluable cases, with 89.5% overall responses (complete response+partial response) versus 75%, respectively (P < 0.001). At the time of an analysis performed in July 1995 (after a median follow-up period of 37 months), overall survival was also longer in the HD-CLB treatment arm (median survival, 68 months) than in the CHOP treatment arm (median survival, 47 months) (P < 0.005). Toxicity was acceptable and comparable in the two treatment arms. The current study showed that HD-CLB is an effective and well-tolerated therapeutic option for patients with advanced and/or progressive CLL. Therefore, the authors recommend its wider use, possibly in comparison with and/ or in combination with new therapeutic agents, such as purine analogues.