Correlation of the immune tumor microenvironment (I-TME) with gene expression profiles as prognostic and predictive factors in patients (pts) with metastatic renal carcinoma (mRCC) treated with immunotherapy (Meet-URO 18 I-TME study).

TPS753 Background: Several studies suggested that response to immunotherapy may be influenced by many factors, including peripheral blood biomarkers, the composition of I-TME and different molecular expression pathways. In mRCC patients, immunotherapy has become part of clinical practice, but the identification of patients most likely to respond to checkpoint inhibitors is still an unmet clinical need. Moreover, there are no validated and clinically applicable gene expression panels as prognostic and/or predictive response biomarkers. To date, three major groups of immune-related gene expression were identified in mRCC: the angiogenesis pathway, the T-effector pathway and the mixed pathway (doi: 10.1038/s41598-020-58804-y). Each group of gene expression seems to be responsible for a different type of immune response in the I-TME. However, a significant association with treatment response to immunotherapy has not yet been demonstrated. Methods: The Meet-URO 18 is a multicentric retrospective translational study aimed at identifying distinctive molecular patterns of the I-TME with a prognostic and predictive role in mRCC (primary objective). Pretreated mRCC patients receiving ≥2nd line nivolumab have been divided according to clinical benefit in responders (PFS ≥ 12 months) versus non-responders (PFS ≤ 3 months). Secondary objectives include the correlation between primary tumor and metastases to identify a potential inter-tumor heterogeneity and the correlation with survival and response outcomes. Histological samples of primary tumors and/or metastases have been collected for the transcriptomic analyses together with clinical data of patients from medical records. The transcriptomic characterization of the I-TME of the primary tumor and/or metastases will be performed using the analytical platform "nCounter" of NanoString®, which analyzes the expression of 71 genes involved in angiogenesis, immunomodulation mediated by T-effector response, mechanisms of tumor invasion and mechanisms of calcium channel flows. The gene-panel include a group of 66 genes previously demonstrated to be related in the immune-response in mRCC (doi: 10.1038/s41598-020-58804-y) and 5 housekeeping genes (RPS13, PPIA, RPL27, RP2, B-ACT).