Klin Onkol 2003; 16(4): 178-183.
Summary: The treatment options for chronic lymphocytic leukemia (CLL) have dramatically increased in the last few years. Promising results have been reported with new cytotoxic agents such as the purine analogues fludarabine and 2-chlordeoxyadenosine, either at first diagnosis or at relapse. Nevertheless, all patients with CLL relapse after initial response. Since residual leukemia cells are very likely to be the origin of the clinical relapse, there is a need for new therapeutic approaches with different mechanism of action to eliminate these residual cells. These approaches include imunotherapeutic strategies. Monoclonal antibodies are thus being actively investigated. In clinical trials the unconjugated anti-CD20 antibody rituximab achieved promising results in the treatment of patients with relapsed or refractory low-grade non-Hodgkin’s lymphoma. Nowadays, there is clinical experience with rituximab in CLL patients. However, the exact role of this agent in the treatment of CLL has still to be determined in ongoing and future trials. In CLL patients the amount of CD20 on the cell surface is moderate, this being a possible reason for the low response rate to rituximab in the some studies reported so far. The effectiveness of rituximab might be improved by escalating the dose or modifying the treatment schedule. Effort is being focused on combining rituximab with chemotherapy. Furthermore, the potential risks of tumor lysis and anaphylaxia for rituximab must be taken into account. The present review will discuss the basic principles of this unconjugated monoclonal antibody and consider its role in the treatment of patients with CLL.
