Immune Checkpoint Inhibition Treatment Outcomes in Advanced Renal Cell Carcinoma

Abstract

Abstract Title: Characterizing Outcomes of Immune Checkpoint Inhibition Treatment in Patients with advanced Renal Cell Carcinoma Michael Pannell1, Maishara Muquith1, David Hsieh2, MD 1. University of Texas Southwestern Medical School 2. University of Texas Southwestern, Internal Medicine, Division of Hematology-Oncology Background: Immune checkpoint inhibitors (ICIs) have become a standard of care treatment for patients with metastatic renal cell carcinoma (mRCC), with previous retrospective studies demonstrating potential benefits with increased tumor sensitivity to sequential treatment after ICI failure. An increasingly important area of investigation is characterizing the outcomes of ICI treatment and subsequent therapies in patients with advanced renal cell carcinoma. We examine characteristics of ICI treatment outcomes in a real-world cohort. Methods: This IRB approved retrospective cohort study included patients with advanced renal cell carcinoma treated with palliative-intent PD-1/PD-L1 inhibitors at a single institution between 2016 and 2019. Clinical data including age, sex, cancer type, and treatment lines were obtained from the electronic medical record. Radiographic responses were determined from available CT/MRI studies and categorized using Response Evaluation Criteria In Solid Tumors 1.1 criteria. Response categories include complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Results: Of 110 patients with mRCC that initiated ICI therapy between 2016 and 2019, 95 were treated with palliative intent and had subsequent imaging to evaluate their response. The overall objective response rate was 18.8% (n=18), with 18 patients demonstrating a partial response to treatment, 26 demonstrating stable disease, and 52 showing disease progression. ICI therapy as 1st line palliative treatment demonstrated the highest objective response rate of 27.5% (n=14), decreasing for subsequent treatment lines (13% and 0% for 2nd and 3rd+). Progression Free Survival (PFS) and Overall Survival (OS) were measured across ICI type and treatment line, with overall median values being 82 and 926 days, respectively. Additionally, patients were treated with either nivolumab monotherapy, nivolumab/ipilimumab combination, or pembrolizumab concurrent axitinib. Those treated with nivolumab monotherapy had a median PFS=79.5 days (n=32) and a median OS=1068.5 days (15 cases ongoing at the time of data analysis), compared to nivolumab/ipilimumab median PFS=83 days (n=55) and median OS=706 days (22 ongoing), and pembrolizumab median PFS=169 days (n=9) and median OS=559 (4 ongoing). Conclusion: This study suggests that specific ICI therapies and treatment line may be associated with objective response and survival in patients with mRCC. Further identifying these associations could result in improved clinical outcomes.