Examining the real-world utility of immune checkpoint inhibitors in genitourinary oncology: A single-institution retrospective.

Abstract

e17112 Background: Immune Checkpoint Inhibitors (ICI) are increasingly utilized for genitourinary (GU) malignancies. However, data is lacking on the efficacy of these drugs in “real-world” populations - patients who do not fit the strict clinical trial criteria, but may still benefit from therapy. We performed a retrospective analysis of patients receiving ICI at a single tertiary-care institution, with special attention to clinical trial enrollment, adverse events, progression and survival. Methods: Patients receiving ICI for GU malignancies at Thomas Jefferson University Hospital from January 2017 to January 2019 were identified. Descriptive statistics of treatment and pathologies were performed. Progression-free survival (PFS) was calculated from start of ICI to documentation of progression or last follow-up. PFS and overall survival were assessed using Kaplan Meier log-rank test, stratified by trial enrollment. Results: 111 patients were included: 37 on ICI clinical trial, 70 received ICI “off-trial” and 4 received ICI in both settings. 11 patients (10%) underwent multiple courses of ICI throughout treatment. The number of patients initiating ICI increased annually; by 2018, the number of patients initiated on ICI “off-trial” exceeded those initiating ICI “on-trial” (79% vs 21%). Treated pathology included Urothelial Carcinoma (UC; 42%), Renal Cell Carcinoma (RCC; 28%), and Prostate Adenocarcinoma (PCa; 20%). “Off-trial” ICI was more often administered later in the disease course, compared to a more even distribution of “on-trial” ICI administration. Mean PFS and OS for both cohorts can be seen in Table. Conclusions: As seen in our single-institution referral center, the use of immune checkpoint inhibitors has significantly increased – and is now more commonly used off-trial than on-trial. As their use becomes more common, their efficacy in “off-trial” populations must be further investigated. [Table: see text]