A team of researchers at Roswell Park Comprehensive Cancer Center have identified a biomarker that could be used to predict how well immune checkpoint inhibitors will be tolerated.
Immune checkpoint inhibitors (ICI) activate anti-tumour defences either through the disruption of inhibitory interactions between antigen-presenting cells and T cells at so-called checkpoints or else through the stimulation of activating checkpoints. Not all patients can tolerate ICI well; side effects can be severe, including colitis, which is one of the most common.
Pre-treatment biomarkers are of limited value in predicting response to ICI. Tumour biopsy shortly after ICI therapy is started can provide helpful information, but is invasive and difficult to do in some certain cancers.
Uncovering blood-based biomarkers that reflect the change of the tumour microenvironment and can predict a patient’s response to ICIs could improve current treatment regimens significantly, Dr. Ito notes. The team’s previous research indicates that T cells with varying levels of the chemokine receptor CX3CR1 responded differently to ICI therapy.
Based on those findings, the researchers sought to test CX3CR1 as a T cell biomarker in ICI therapy. They found that ICI therapy is linked to increased frequency and clonality of some CX3CR1-positive T cells; that the frequency of these CD8+ T cells stays high during ICI therapy; and that there are many genomic similarities between CD8+ tumour-infiltrating lymphocytes and this subset of CX3CR1-positive T cells.
Fumito Ito, MD, PhD, FACS, explained: “Although ICIs revolutionized the cancer treatment for significant numbers of people, many cancer patients do not respond to them, and some develop severe toxicity.”
“Currently, we are in need of a better biomarker to predict the response to immunotherapy, which is part of standard treatment in advanced and metastatic lung cancer,” said Hongbin Chen, MD, PhD. “This study sheds light on a promising blood-based biomarker that is potentially very useful in identifying which patients with lung cancer are most likely to benefit from immunotherapy. We look forward to investigating its utility in further clinical research.”
Source: News-Medical.Net
Journal information: Yamauchi, T., et al. (2021) T-cell CX3CR1 expression as a dynamic blood-based biomarker of response to immune checkpoint inhibitors. Nature Communications.doi.org/10.1038/s41467-021-21619-0.
