A Screening visit will be conducted within 28 days before baseline (baseline being Day 1, Cycle 1, before study drug administration). At this visit, a medical history will be obtained and a complete physical examination will be performed including vital signs, height, weight, and a 12-lead electrocardiogram. A neurological questionnaire will also be completed. Disease assessments will be performed, including performance status, bone marrow aspirate and biopsy, Beta2-microglobulin, serum protein electrophoresis with quantification of immunoglobulins and immunofixation studies, CT scanning of the chest, abdomen and pelvis. Clinical laboratory tests including a complete blood count plus differential, electrolytes, urea, creatinine, total bilirubin, SGOT (ALT), SGPT (AST), LDH, total protein and albumin. Patients who meet the eligibility requirements as assessed at the Screening visit will be enrolled in the study and start study drug treatment. Patients will be evaluated after each cycle with serum protein electrophoresis to determine their response to therapy. If patients demonstrate a response or have stable disease at the end of each cycle they will continue to receive therapy. If the patient demonstrates evidence of progressive disease at the end of each cycle then the patient will be removed from study. Modified response criteria updated at the Third International Workshop on Waldenstroms macroglobulinemia will be used to assess response, stable disease (SD), and progressive disease (PD) in this study. Changes of serum monoclonal protein concentration will be assessed from serum protein electrophoresis rather than from nephelometric measurement of serum immunoglobulins. Patients will receive five cycles of therapy. Subsequently, it is strongly advised that blood stem cells will be collected from patients <70 years of age for future high-dose therapy.