Subcutaneous alemtuzumab plus cyclosporine for the treatment of aplastic anemia.

Aplastic anemia (AA) is most frequently due to autoimmune attack on its own stem cells. Alemtuzumab is a monoclonal antibody which recognizes the CD52 antigen on the surface of T and B cells. It has proved useful in autoimmune diseases, lymphoproliferative conditions, and graft versus host disease. Based on its immunosuppressive properties, we treated 14 AA patients with alemtuzumab. Median age was 23 years. Ten milligrams of alemtuzumab were injected subcutaneously each day for five consecutive days. Cyclosporine A was also administered orally at a dose of 2 mg/kg every 12 h for 3 months, and then gradually tapered. Response to alemtuzumab was followed for a median of 20 months. There were eight responses (57.1%), two complete and six partial. Whereas six (42.8%) patients were non-responders. Median complete blood count values on alemtuzumab responders were Hb 13.1 mg/dL, absolute neutrophil count 2.4 x 10(9)/L, and platelets 97.5 x 10(9)/L. A good response was produced in 57% of AA patients with the administration of alemtuzumab, who lacked a stem cell donor.