LAUSR

515Background: Survival outcomes are heterogeneous across different subsets of mRCC pts. Poor risk pts have grim outcomes and are less likely to be enrolled in clinical trials, hence the lack of prospective data characterizing this pt population. We provide a comprehensive analysis of poor risk pts, as defined by three widely used prognostic models, in the era of targeted therapy. Methods: We conducted a pooled retrospective analysis of 4,736 mRCC pts treated on phase II and III clinical trials. Pts were defined as poor risk according to the Memorial Sloan Kettering Cancer Center (MSKCC), International Metastatic Database Consortium (IMDC), and Hudes prognostic risk models. We evaluated overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs) in poor risk pts in each of the risk models in the total cohort and in a subset of pts who remained on treatment for >12 months (mos). The models’ concordance (c-) index was used to assess their prognostic perfor...