Limitations of rituximab in treating primary immune thrombocytopenia and the therapeutic potentials of alternatives.

PURPOSE OF REVIEW: Primary immune thrombocytopenia (ITP), an immune-mediated hemorrhagic disease, features an intricate pathogenesis that involves megakaryocyte malfunction and hyperresponsiveness of the innate and adaptive immune systems. As a second-line drug for ITP, rituximab acts quickly and can produce an initial response rate of up to 60%. However, this response only lasts for a short term, meanwhile challenged by resistance, relapse and side effects. Additionally, no reliable clinical parameters have been proposed for forecasting the therapeutic response of patients. Furthermore, the application of rituximab is restricted in specific populations, including pregnant patients, children with positive antithyroid antibodies, and patients contaminated with HBV.

RECENT FINDINGS: Splenectomy and new drugs that target the thrombopoietin receptor, FcγR, FcRn, B-cells or plasma cells, T-cells, and complement pathways may overcome these shortcomings.

SUMMARY: This article summarizes the barriers limiting the use of rituximab, and discusses the effectiveness and safety of current and fledgling treatment options.