Waldenström's macroglobulinaemia (WM) is a lymphoproliferative disorder characterized by a monoclonal IgM paraprotein and morphological evidence of lymphoplasmacytic lymphoma: the cells are IgM+, IgD+, CD19+ and CD20+ but usually CD5-, CD10- and CD23-. The treatment efficacy is difficult to assess because of the lack of clear diagnostic criteria , good response criteria, and of randomized trials.

The actual treatment is Chlorambucil, an alkylating agent. A purine analogue such as Fludarabine has proven its efficacy on 30 % to 80 % as first line therapy

This study is a phase II b open, prospective, international multicenter trial (England, Dr Johnson, Dr Catovsky, Australia: Dr Seymour) promoted by the French Cooperative Group on Chronic Lymphoid Leukemia in untreated WM, or closely related disorders ( Lymphoplasmacytic lymphoma or splenic marginal zone lymphoma). 366 patients must be included, among them 180 patients in France. Patients will be stratified according to the lymphoproliferative disorder.

The patients will receive Chlorambucil by oral route for 10 days every 28 days (12 cycles) (8 MG/M², 6 MG/M² if patient is more than 75 years old) or Fludarabine by oral route for 5 days every 28 days (6 cycles) (40MG/M², 30 MG/M² if patient is more than 75 years old).

The primary objective is to compare the efficacy (response rate) of Chlorambucil to Fludarabine in previously untreated patients. The secondary objectives are the duration of response, the improvement of hematological parameters, the toxicity, the quality of life, the event free survival and the overall survival.