Interferon-stimulated neutrophils as a predictor of immunotherapy response

Despite the remarkable success of anti -cancer immunotherapy, its effectiveness remains confined to a subset of patients-emphasizing the importance of predictive biomarkers in clinical decision -making and further mechanistic understanding of treatment response. Current biomarkers, however, lack the power required to accurately stratify patients. Here, we identify interferon -stimulated, Ly6Ehi neutrophils as a blood -borne biomarker of anti-PD1 response in mice at baseline. Ly6Ehi neutrophils are induced by tumor -intrinsic activation of the STING (stimulator of interferon genes) signaling pathway and possess the ability to directly sensitize otherwise non -responsive tumors to anti-PD1 therapy, in part through IL12b-dependent activation of cytotoxic T cells. By translating our pre -clinical findings to a cohort of patients with non -small cell lung cancer and melanoma (n = 109), and to public data (n = 1440), we demonstrate the ability of Ly6Ehi neutrophils to predict immunotherapy response in humans with high accuracy (average AUC z 0.9). Overall, our study identifies a functionally active biomarker for use in both mice and humans.