Potentiation of therapeutic immune responses against malignancies with monoclonal antibodies

Immunotherapeutic monoclonal antibodies (mAbs) can be defined as those that exert their functions by tampering with immune system cell molecules, causing an enhancement of antitumor immune responses. Some of these antibodies are agonistic ligands for surface receptors involved in the activation of lymphocytes and/or antigen-presenting cells, whereas others are antagonists of mechanisms that normally limit the intensity of immune reactions. Several mAbs of this category have been described to display in vivo antitumor activity in mouse models. Only anti-CTLA-4 (CD152) mAb has entered clinical trials, but the preclinical effects described for anti-CD40, anti-CD137 (4-1BB), anti-CD102 (intercellular adhesion molecule-2), and regulatory T cell-depleting mAbs should lead to their prompt clinical development. Their use in combination with immunizations against tumor antigens has been reported to be endowed with synergistic properties. This new group of antitumor agents holds promise for at least additive effects with conventional therapies of cancer and deserves intensive translational research.