INTRODUCTION:Monoclonal antibody (mAb)-based products are highly specific for a particular antigen. This characteristic feature of the molecules makes them an ideal tool for many applications including cancer diagnosis and therapy. SOURCES OF DATA:We performed comprehensive searches of PubMed, Medline and the Food and Drug Administration website using keywords such as 'therapeutic antibodies' and 'anti-cancer antibodies'. AREAS OF AGREEMENT:Treatment of cancer patients with antibodies when used alone or in combination with chemotherapy and radiotherapy, or conjugated to drugs or radioisotopes, prolongs overall survival in cancer patients. Currently, there are 14 mAb-based drugs that have been approved for the treatment of cancer patients. AREAS OF CONTROVERSY:The response of cancer patients to antibody therapy can be of short duration. Therapeutic antibodies are expensive and may have side effects. There are no reliable predictive biomarkers for sensitivity or resistance to certain therapeutic antibodies. FUTURE FOCUS: There should be additional studies to discover novel therapeutic targets, to develop more effective antibody-based drugs with fewer side effects, to identify more reliable predictive biomarker(s) for response to therapy with antibody-based drugs and to develop alternative strategies (e.g. transgenic plants, transgenic farm animals) for production of large quantities and more affordable batches of therapeutic antibodies. AREAS TIMELY FOR DEVELOPING RESEARCH:A better understanding of cancer biology, the hallmarks of human cancers and the immune system would lead to identification of additional cell surface biomarkers. These in turn would facilitate the development of novel and biosimilar antibody-based drugs and their routine use as 'magic bullets' for the targeted therapy of human cancers.