Peripheral immune-based biomarkers in cancer immunotherapy: can we realize their predictive potential?

Abstract

The immunologic landscape of the host and tumor play key roles in determining how patients will benefit from immunotherapy, and a better understanding of these factors could help inform how well a tumor responds to treatment. Recent advances in immunotherapy and in our understanding of the immune system have revolutionized the treatment landscape for many advanced cancers. Notably, the use of immune checkpoint inhibitors has demonstrated durable responses in various malignancies. However, the response to such treatments is variable and currently unpredictable, the availability of predictive biomarkers is limited, and a substantial proportion of patients do not respond to immune checkpoint therapy. Identification and investigation of potential biomarkers that may predict sensitivity to immunotherapy is an area of active research. It is envisaged that a deeper understanding of immunity will aid in harnessing the full potential of immunotherapy, and allow appropriate patients to receive the most appropriate treatments. In addition to the identification of new biomarkers, the platforms and assays required to accurately and reproducibly measure biomarkers play a key role in ensuring consistency of measurement both within and between patients. In this review we discuss the current knowledge in the area of peripheral immune-based biomarkers, drawing information from the results of recent clinical studies of a number of different immunotherapy modalities in the treatment of cancer, including checkpoint inhibitors, bispecific antibodies, chimeric antigen receptor T cells, and anti-cancer vaccines. We also discuss the various technologies and approaches used in detecting and measuring circulatory biomarkers and the ongoing need for harmonization.

The Oral Microbiome and Cancer

“…Immunotherapy approaches have shown potential in treating hematopoietic (185,186) and solid cancers (187)(188)(189). However, the efficacy of immunotherapy is still limited by the variability of the immune response in different patients and the different susceptibility of tumor types (190,191). The emerging knowledge of the ability of the gut microbiome to modulate the response to immunotherapy offers new possibilities to improve its efficacy by targeting the microbiome.…”

Electroporation-Based Treatments in Small Animal Veterinary Oral and Maxillofacial Oncology

“…Finally, the reasons for clinically observed individually different responses to treatment remain to be elucidated with the identification of biomarkers that will enable the better selection of patients that will benefit from the treatment and prediction of response and recurrence ( Figure 5 ). Specific T cell populations in whole blood can be potentially used as biomarkers for early recurrence, showing that additional treatments should be applied ( 101 , 102 ). High expression of immune checkpoint inhibitors, such as PD-1 and PD-L1, as well as their binding and consecutive immune evasion of the tumor, could also be used as predictive factors for the response to immunotherapy ( 103 , 104 ).…”

T cell regeneration after immunological injury

“…Although the prognostic significance of this association has still to be further characterized in larger studies, a highly diverse pool of T cells before therapy correlates with improved outcome after immune checkpoint blockade therapy [16][17][18][19] . Thus, there is considerable interest in developing approaches to evaluate the quantity and quality of T cells before and during different forms of immunotherapy to guide treatment directions, monitor immune responses and ultimately identify functional biomarkers to predict clinical outcomes 20 .…”