Toxicity-related immunotherapy discontinuation and outcome in patients with advanced renal cell carcinoma treated with immune-based combinations (ARON-1 study)

: The advent of immunotherapy (IO) has revolutionized the therapeutic landscape of advanced renal cell carcinoma (RCC). The aim of this study is to analyze clinical outcomes in patients who discontinued IO in metastatic RCC first line in a real-world setting. We retrospectively collected data about 1077 patients aged ≥18 years with a histologically confirmed diagnosis of clear cell RCC and histologically or radiologically confirmed metastatic disease, treated in 52 centers from 20 countries, between January 1, 2016 and April 1, 2024, from all three International metastatic renal cell carcinoma (mRCC) Database Consortium risk groups (favorable, intermediate, and poor). Each patient was treated in front-line with IO + Tirosine Kinase Inhibitor or IO + IO combinations. In this study we analyzed survival outcomes comparing patients who interrupted IO versus patients who continuously received it and multivariable analysis. We analyzed the clinical behavior of 185 patients who interrupted IO treatment due to SAE, 127 patients with IO-tyrosine kinase inhibitor, 58 patients with IO-IO versus 892 patients who do not discontinue IO treatment. No significant differences in OS were found in patients who discontinue treatment versus no discontinuation. Moreover, time to discontinuation seemed to be an OS predictor, being inferior in patients who interrupted IO in the first to third month versus patients who discontinued treatment after this time data. The ARON-1 study offers a comprehensive examination of toxicity-related IO discontinuation in advanced RCC, contributing to a better understanding of balancing treatment efficacy with tolerability.