Prospective, Multicentric, Phase II Randomized Controlled Trial on Two Parallel Groups Comparing the Efficacy of Two Immunosuppressive Drugs (methotrexate, Cyclophosphamide) in Large Granular Lymphocytes Leukemia

LGL leukemia represents a rare subtype of chronic T or NK lymphoproliferative disorders. It is an indolent disease, the main hematological or autoimmune complications lead to a treatment in more than 60% of patients. Investigators set up at the University Hospital of Rennes, a database of more than 300 patients with LGL leukemia from major French services that support this disease, and published in 2010 the largest series of patients in the world (n = 229). However, the limited heterogeneity and retrospective data collected, as all previously released, makes it difficult the proposal of consensual treatment options. If first and second line treatments are based on the use of immunosuppression with methotrexate, cyclophosphamide, or cyclosporin A, no molecule has proven superiority over others. Methotrexate and cyclophosphamide are mainly used in the first line. Invetigators just have in the literature data on about 100 patients treated with either of these drugs. Combining the results of our series with those in the literature, invetigators estimate the respective overall response rate (RG) and complete response rate (CR) in 55% and 30% for methotrexate, and 60% and 50% for cyclophosphamide. Thus, there are four objective in this study : 1. to compare the respective efficacies of methotrexate and cyclophosphamide when administered as first-line therapies in patients suffering from T/NK LGL leukemia with severe neutropenia or neutropenia associated with infections, and/or anemia requiring transfusions, and/or auto-immune associated disease 2. to evaluate the percentage of patients refractory to methotrexate or cyclophosphamide for which a second line treatment is efficacious 3. to explore, in case of non-response to the first-line therapy, the efficacy of ciclosporine A, the comparison being performed with the treatment which was not administered in the first-line therapy 4. to evaluate the response rate according to the phenotypic subtype of LGL leukemia.