Awaiting a new era of cancer immunotherapy

A major challenge in cancer therapy is the lack of specificity for cancer cells. Antibody-based therapies have better specificity and, thus, improved efficacy over standard chemotherapy regimens. Monoclonal antibodies (mAb) constitute the most rapidly growing class of human therapeutics and are proven agents for recognizing and destroying malignant cells. However, the development of antibody therapies has focused only on targeting extracellular (cell-surface or secreted) proteins rather than intracellular targets (within cells, such as phosphatases and/or kinases and transcription factors), because antibodies are generally believed to be too large to enter cells, resulting in a large untapped source of intracellular therapeutic targets. Recently, we presented evidence that suggests that intracellular proteins with high expression in cancer cells are useful targets for mAb-based or vaccination immunotherapies, thus challenging current understanding. Here, we further discuss the concept and future uses of these immunotherapies against a large pool of intracellular oncoproteins for cancer therapy. This line of research has the potential to vastly expand the field of antibody therapy and usher in a new era of cancer vaccines. Cancer Res; 72(15); 3715–9. ©2012 AACR.