Idiopathic or immune thrombocytopenic purpura is an autoimmune disorder characterized by a low platelet count and various forms of bleeding and bruising. In the United States, an estimated 60,000 adults have been diagnosed. Management depends on the severity of bleeding, with the goal of treatment traditionally being platelet counts > 30 x 109/L. Initial management includes oral steroids (prednisone or dexamethasone) with intravenous anti-D immunoglobulin for Rh+ individuals who are steroid intolerant. Failure of this regimen leads to supplemental therapy with intravenous immunoglobulin G; many patients go on to splenectomy. However, 40% to 50% are refractory to these therapies and a variety of drugs are then employed, e.g., rituximab, danazol, and cyclophosphamide. For patients with idiopathic or immune thrombocytopenic purpura who have failed first-line therapies (drugs, splenectomy), treatment is a challenge. Second-line therapies provide variable and often temporary or unsatisfactory results, as well as significant adverse events.