Characterization of patients (pts) with poor risk metastatic renal cell carcinoma (mRCC): Results from a pooled clinical trials database.

Abstract

515 Background: 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 performance. Results: We identified 1145 (24.2%), 904 (19.1%), and 1901 (40.1%) poor risk pts by IMDC, MSKCC, and Hudes models, respectively. The majority were <65 years of age (70-73%) with clear-cell histology (85-88%), prior nephrectomy (62-66%), and no prior systemic therapy (80-86%). The efficacy and toxicity outcomes as well as the c-indexes for each of the models are reported in the table below. Additionally, 9-14% of poor risk pts remained on therapy for >12 mos and had higher OS (29.8-35.2 mos) and ORR (42-53%). Conclusions: In this large database of poor risk mRCC pts, we highlight that the models have similar predictive accuracy in the targeted therapy era. We also demonstrate that poor risk pts continue to have dismal outcomes and should be considered for trials of novel agents and combinations. A subset of these pts appears to derive prolonged clinical benefit and should be further explored.[Table: see text]