T-cell CX3CR1 expression as a dynamic blood-based biomarker of response to immune checkpoint inhibitors

Abstract Immune checkpoint inhibitors (ICI) have revolutionized treatment for various cancers; however, durable response is limited to only a subset of patients. Discovery blood-based biomarkers that reflect dynamic change the tumor microenvironment, and predict ICI, will markedly improve current regimens. Here, we investigate CX3C chemokine receptor 1 (CX3CR1), marker T-cell differentiation, as predictive correlate ICI therapy. Successful tumor-bearing mice with increases frequency clonality peripheral CX3CR1 + CD8 includes an enriched repertoire tumor-specific tumor-infiltrating T cells. Furthermore, increase in circulating cells early after initiation anti-PD-1 therapy correlates survival patients non-small cell lung cancer. Collectively, these data support expression on-treatment predictor