Therapeutic checkpoint targets: Evaluation of co-expression profiles in individual tumor and immune cells in the tumor microenvironment of FFPE tissue.

176Background: Interactions between tumor and immune cells in the tumor microenvironment (TME) play a key role in tumor progression and treatment response with accumulating evidence indicating a crucial role for tumor infiltrating immune cells. Although infiltrating cytotoxic T lymphocytes (CTLs) have been correlated with improved clinical outcome, they are ineffective in eradicating tumors due to their inhibition by immune checkpoint molecules. Immune checkpoint inhibitors have demonstrated therapeutic efficacy and durable response for several tumor types including non-small cell lung cancer (NSCLC). However, the majority of patients are resistant or relapse after initial response. Characterizing the TME for checkpoint expression with single-cell and spatial resolution can provide critical insight into new immunotherapeutic strategies and identify new predictive biomarkers for stratifying and identifying patients most likely to benefit from immunotherapy including PD-1/PD-L1 immune checkpoint blockade. M...