Type, timing, and risk factors associated with immune-related adverse event development in patients with advanced genitourinary cancers treated with immune checkpoint inhibitor.

Abstract

480 Background: Immune related adverse events (IRAEs) with immune checkpoint inhibitor (ICI) therapy are well recognized, but predictors for IRAEs are not well defined. We aim to characterize the type, timing, and clinical risk factors associated with (w/) IRAEs in ICI-treated, advanced urothelial carcinoma (UC) and renal cell carcinoma (RCC) patients (pts). Methods: We retrospectively reviewed charts of pts w/ advanced UC and RCC who received at least 2 ICI doses at our institution from 1/1/10 to 10/31/18. Patient baseline characteristics, treatment course, and clinical outcomes were collected. IRAEs were identified and graded (GR) based on CTCAE (v.4.0). Fisher’s exact test was used to study the differences between pts w/ versus without IRAE. Results: Of the 71 pts identified (UC n = 53; RCC n = 18), 27 pts (38%) developed IRAEs with 42 total events (38% GR1, 60% GR2, and 2% GR≥3) [table]. The majority of pts with dermatitis (70%) also developed a secondary, systemic IRAE(s). Systemic steroid (SS) was required in 17 events. The median time to any IRAE was 17.5 weeks (w, range 1-93). ECOG ≤ 1 predicted IRAE development (p < 0.05). No other characteristics (demographics, co-morbidities, metastatic sites, ICI type, line of therapy, and duration of ICI > 12w) were associated with IRAE. Conclusions: In our study, good function status is associated with the development of IRAE. Time to IRAE ranged from immediately to 93w after initiating ICI. Clinical validation with additional datasets will be needed to confirm these findings. [Table: see text]