Cancer immunotherapy: A need for peripheral immunodynamic monitoring

Immunotherapy has become an important approach for treating different tumours which has shown significant efficacy in numerous clinical trials, especially those using new checkpoint inhibitors and adoptive cell therapy, which have rapidly become widespread after being approved. However, analysis of peripheral immune biomarkers before and after immunotherapy and their relationship to clinical responses and disease prognosis have rarely been performed in clinical trials. In this review, we examine dynamic changes in the immune system before and after therapy by analyzing recent clinical trials of immunotherapy in patients with cancer that focused on checkpoint inhibitors and adoptive cell therapy. Our aim was to identify circulating biomarkers which can specifically predict clinical response and prognosis, as well as toxicities of immunotherapy. Through this approach, we hope to advance our understanding of the mechanisms of immunotherapy with the goal of developing individualized treatment for cancer patients.