Combination Immune Checkpoint Blockade Regimens for Previously Untreated Metastatic Renal Cell Carcinoma: The Winship Cancer Institute of Emory University Experience.

Introduction: There are three combination immune checkpoint inhibitor (ICI)-based regimens in the first-line setting for metastatic renal cell carcinoma (mRCC). Currently, there is limited real-world data for clinical outcomes and toxicity in mRCC patients treated with first-line ICI-based regimens. Methods: We performed a retrospective review of 49 mRCC patients treated with ICI-based combination regimens in the standard of care setting at the Winship Cancer Institute of Emory University from 2015-2020. We collected baseline data from the electronic medical record including demographic information and disease characteristics. Immune-related adverse events (irAEs) were collected from clinic notes and laboratory values. The primary clinical outcomes measured were overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Results: The median age was 65 years, and most patients (80%) were males. The majority were White (86%) and had clear cell RCC (83%). Most patients had an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 (43%) or 1 (45%). Approximately one-half (49%) had at least three sites of distant metastatic disease. Most patients (88%) received nivolumab and ipilimumab. More than one-half (53%) of patients experienced an irAE, with 13 (27%) patients having treatment delayed and 18% discontinuing treatment for toxicity. The median OS was not reached, and the median PFS was 8.0 months per a Kaplan-Meier estimation. More than half of patients (53%) had a PFS > 6 months, and 22% had PFS > 1 year. The ORR was 33% for the entire cohort, and 7% of patients had a complete response. Conclusion: We presented real-world efficacy and toxicity data for front-line ICI combination treatment regimens. The ORR and median PFS were lower in our cohort of patients compared to the available data in the clinical trial setting. This was likely because of more advanced disease in this study. Future studies should provide additional data that will allow comparisons between different ICI combination regimens for untreated mRCC.