Monoclonal antibody-based therapies for hematologic malignancies

Purpose: To review recent advances in the development and clinical roles of monoclonal antibody (MoAb)-based therapies in the treatment of hematologic malignancies. Design: A search of MEDLINE and CANCERLIT was conducted to identify relevant publications. The bibliographies of these references also were used to identify articles and abstracts. These references were then reviewed. Results: In the two decades since the first patient was treated with MoAb therapy, there have been significant advances in the biology, pharmacology, and clinical application of MoAb-based therapies. Three distinct fields of research have emerged: unconjugated MoAbs, immunotoxin- conjugated MoAbs (ITs), and radionuclide-conjugated MoAbs (RICs). The unconjugated MoAbs are less toxic but depend on host mechanisms to mediate cytotoxicity. The ITs carry a potent toxin, although at the cost of a narrow therapeutic index that may limit clinical use. The RICs offer significant potency, even in refractory disease, but their complexity may limit their use to large cancer centers. The current challenges in the development of MoAb- based therapies are to identify the proper target antigens, contend with bulk disease in which penetration may be limited, and choose the optimal clinical settings for their use, such as the minimal residual disease state or in combination with conventional chemotherapy. Conclusion: Although significant research is still needed, MoAb-based therapies promise to offer new options for the treatment of patients with hematologic malignancies.