Impact of steroid use among patients with renal cell carcinoma (RCC) who develop immune-related adverse events (irAE).

4530 Background: Immune checkpoint inhibitor (ICI) therapy has become a standard therapy in the treatment of advanced renal cell carcinomas (RCC). This has led to a proportional increase in the frequency of immune related adverse events (irAE), however. While increasing evidence suggests that irAE may be correlated with benefit from ICI, the impact of steroids to mitigate irAE’s remains unclear. Methods: We analyzed records of patients with RCC treated with an ICI at the USC Norris Comprehensive Cancer Center, Keck Hospital of USC, and LAC+USC Hospital from 2015-2021. Statistical analysis was performed using R. The Kaplan-Meier model was used to calculate progression free survival (PFS) and overall survival (OS). A log-rank test was used to determine if differences in PFS/OS were statistically significant. Results: Out of a total 841 cancer patients treated with ICI, 107 RCC patients were identified. The median age was 60 (range 20-91). The two most common represented ethnicities were 48 Hispanic/Latino (44.9%) and 37 Caucasian (34.6%). The patient population include 64 male patients (59.8%) versus 43 female patients (40.2%). Most had metastatic disease (74.8%) versus local disease (25.2%), and most patients (80.4%) received ICI therapy as initial therapy. Only 6 patients (5.6%) were given combination ICI therapy. The three most common systems affected by irAE were endocrine (18.7%), dermatologic (16.8%), and renal (14.0%). Of the irAE that occurred, 21.5% were categorized as CTCAE grade III or higher. The median PFS of the irAE group was 51.8 months (95% CI 10.0 – 51.8) versus 11.2 months (95% CI 2.7 – 13.8) in the no irAE group. The median OS of the irAE group was 55.0 months (95% CI 23.9 – 55.0) versus 15.6 months (95% CI 13.5 – 23.5). The occurrence of irAE was associated with both statistically significantly increased PFS (p = 0.02) and OS (p = 0.007). The median PFS of patients receiving steroids to treat irAE was 6.5 months (95% CI 3.9 – 9.2) compared to 12.5 months (95% CI 10.4 – 12.5) in the group with irAE who did not receive steroids. The use of steroids was associated with statistically significant worse PFS (p = 0.04) and worse OS but not at statistical significance (p = 0.2). Conclusions: The occurrence of irAE was associated with improved PFS and OS in RCC patients treated with ICI. Furthermore, the use of steroids among patients with irAE was associated with worsened PFS, but not OS. Although steroids should still be used as clinically indicated for the management of irAE, clinicians should be judicious as they may blunt tumor response to ICI treatment.