A Phase II Study of Alemtuzumab in Autoimmune Cytopenias

The majority of cases of autoimmune cytopenias, which includes immune thrombocytopenia (ITP), autoimmune hemolytic anemia, autoimmune neutropenia (AIN) and pure red cell aplasia, will respond to conventional immunosuppressive therapy with or without splenectomy. There is, however, a group of patients with refractory or chronically relapsing autoimmune cytopenias causing life-threatening hemorrhages, infections or anemia. Further problems include the short- and long-term side-effects of corticosteroids, and the potential toxicity of immunosuppressive and cytotoxic agents. An alternative and less toxic approach in these patients may be the treatment with Campath-1H, a humanized IgG monoclonal antibody specific for the CD52 antigen and present on human lymphocytes and monocytes. The main effect of Campath-1H is on T cell and it results in a prolonged and profound depletion of the CD4 and CD8 subpopulations, particularly the CD4 population, and this might "reset" the immune system without the need for total immune ablation.Therefore, this study is designed to investigate safety and efficacy of repeated Campath treatment cycles in autoimmune cytopenia.In order to minimize possible side effects of accumulating Campath, the 3 treatment cycles will be administered in consecutively reduced doses.