Rituximab Maintenance Versus Observation After First-line Immunochemotherapy by FCR in Older Patients With Chronic Lymphocytic Leukemia

RATIONALE: Classical chemotherapy does not cure advanced chronic lymphocytic leukemia (CLL) despite new drugs. Rituximab is a monoclonal antibody directed against CD20 surface antigen on B lymphocytes and leads to apoptosis of CD20 positive B lymphocytes. The highest response rate yet published in the treatment of first-line CLL has been obtained by the association of fludarabine, cyclophosphamide and rituximab (FCR). Now, the question is whether this response can be improved, as some trials showed that eradication of minimal residual disease (MRD) in CLL is associated with a longer treatment-free and overall survival. Maintenance therapy using rituximab has been recently approved as a means of prolonging remission in patients with indolent non Hodgkin's lymphoma. Maintenance therapy with rituximab could be of interest in treatment of MRD in CLL and prolonging remission and survival times. PURPOSE: The overall purpose of the study is to determine the value of immunotherapy maintenance with single agent rituximab in comparison with no further treatment (observation ) for previously untreated chronic lymphocytic leukaemia in elderly (\>65 years) patients who respond to induction immunochemotherapy with FCR.