Efficacy and long-term toxicity of the rituximab-fludarabine-cyclophosphamide combination therapy in Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia is generally treated with alkylating agents, purine analogs and monoclonal antibodies, alone or in combination. We report the outcomes of 82 patients (median age 61 years) treated with the RFC combination. Twenty-five patients were treatment-naive. RFC was administered every 4 weeks, for a median of five cycles. At treatment discontinuation, the overall response rate was 85.4%. The responses improved after treatment discontinuation in 25 patients, with a median time to best response achievement of 10.8 months, raising the major response rate (PR, VGPR and CR) from 64.6% to 76.8%. With a median follow-up of 47 months, the median progression-free survival time had not been reached (67% PFS at 48 months) and was influenced by age and treatment status before RFC. Likewise, the median time to next therapy had not been reached. Two cases of myelodysplastic syndrome/AML and 3 cases of transformation to aggressive lymphoma occurred. Thirteen patients died. The 3-year overall survival rate was 90%. Long-lasting cytopenias occurred in 19 patients. The RFC combination thus gave a high response rate and durable responses, even in heavily treatment-experienced patients. The high incidence of long-lasting cytopenia might be reduced by giving fewer courses and thereby minimizing myelotoxicity. Am. J. Hematol. 91:782-786, 2016. (c) 2016 Wiley Periodicals, Inc.