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

Large Granular Lymphocyte (LGL) leukemia is a clonal disorder involving tissue invasion of marrow, spleen and liver. Clinical presentation is dominated by recurrent infections associated with neutropenia, anemia, splenomegaly, and auto-immune diseases, particularly rheumatoid arthritis. Both T cell and NK cell subtypes of LGL leukemia are indolent disease and considered as a chronic illness and lead to a treatment in more than 60% of patients.

LGL leukemia displays a chronic clinical course. Recommendations regarding therapy are similar for both subtypes. Indications for treatment include 1) severe neutropenia (ANC <500 mm3); 2) neutropenia (ANC <1500mm3) with symptomatic recurrent infections; 3) symptomatic or transfusion-dependent anemia and 4) associated autoimmune conditions requiring therapy, most often rheumatoid arthritis.

There is no standard treatment for patients with LGL leukemia. The numerous case reports published do not provide a consensus for a particular treatment. All the six largest series published in the literature so far (collecting data on more than 40 patients) are retrospective.

Immunosuppressive therapy remains the foundation of treatment including single three agents i.e. methotrexate, oral cyclophosphamide and ciclosporin A. However prospective trials involving large numbers of patients have not been performed and no molecule has proven superiority over others.

Invetigators 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. Combining the results of our series with those of the literature, invetigators estimate that overall response rate and complete response rate are 55% and 30% with methotrexate, 60% and 50% with cyclophosphamide, and 55% and less than 20% with ciclosporine A, respectively.

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.