Immune system plays a critical role in controlling and fighting cancer. In recent studies, several antibody therapies capable of restoring or enhancing the immune response have demonstrated significant success for patients with a variety of malignancies. Blockade of the negative immuno-logic regulators, CTLA-4 and PD-1, can result in anti-tumor immunity and revolutionized cancer treatment. Because of the successes with immune checkpoint inhibitors in cancer immunotherapy, many combinational approaches and new agents are being developed.
However, the efficacy of immune checkpoint inhibitors vary among different tumor types and genomics alternations in cancer cells, only 20%to 30% of patients are likely to benefit from the treatment. Therefore, it is critical to have an accurate way to predict the response to the drugs. Recent studies have revealed the high nonsynonymous mutation burden in tumor and the number of neo-antigens to be presented by MHC are associated with response to the therapy.