Predicting Clinical Efficacy of Immunotherapy Using Pre-treatment andContinuousMonitoring of PD-L1 TPS/CPS on CTCs, and Immunity Exhaustion Scores

Head and neck cancer is ranked among the fifth to eighth most prevalent cancers worldwide and is associated with a high mortality rate. Immunotherapy has been established as the first-line standard of care for recurrent and metastatic head and neck cancer. However, patient selection is currently guided by the histological Combined Positive Score (CPS) (KN-048) or Tumor Proportion Score (TPS) (KN-040). A significant limitation is the inability to re-test tumor tissue when disease status changes necessitate therapeutic adjustment, as new tissue is often unavailable. Consequently, liquid biopsy, which allows for repeatable testing and thus constitutes a dynamic biomarker, becomes crucial. Nevertheless, its definitive role in predicting the efficacy of IT has yet to be thoroughly investigated. In this study, our team endeavors to define the CPS score of peripheral circulating tumor cells (CTCs) and evaluate the predictive ability of CTC TPS/CPS for clinical response, using objective clinical outcomes as the ultimate measure.