CD22 as a target for cancer therapy

Targeted therapies with monoclonal antibodies have been increasingly incorporated into the treatment for both lymphoid and myeloid hematological malignancies. Rituximab, the first approved monoclonal antibody for the treatment of cancer, has revolutionized our approach to the management of chronic lymphocytic leukemia and non-Hodgkin's lymphoma. However, there is still an unmet medical need for novel therapeutic approaches, especially for patients in the relapsed/refractory setting. Therapeutic agents with specificity against different surface antigens on malignant B cells hold promise for improving clinical outcome in these patients. Throughout the last decade, CD22, a B-cell-restricted phosphoglycoprotein of the immunoglobulin superfamily, has gained considerable interest as a therapeutic target for B-cell-directed therapies. Several novel therapeutic agents that selectively target CD22 are being developed as an alternative approach for cancer treatment. This review summarizes the current knowledge of CD22 and discusses the rationale for targeting CD22 in B-cell malignancies with immunotherapeutic agents. This review also describes some of the most promising investigational anti-CD22 agents for the treatment of B-cell malignancies.