High circulating IL-6/IL-8 is associated with intratumoral myeloid contexture and poor outcomes in advanced renal cell carcinoma patients treated with PD-1 blockade.

Purpose: The phase II NIVOREN GETUG-AFU-26 study assessed the safety and activity of nivolumab in a real-world population with pretreated advanced clear cell renal cell carcinoma (aRCC). A comprehensive translational research program was conducted including blood and tissue-based analyses. Herein we assessed circulating factors at baseline, their association with intratumoral immune contexture and outcomes.

Experimental Design: Baseline blood samples were prospectively collected from 353 patients included in the NIVOREN trial. A cohort of 80 patients including 40 responders and 40 with primary progressive disease, was used for biomarker discovery, with fourteen soluble factors (VEGF,VCAM-1, IL-6, IL-7, IL-8, IL-10,APRIL, BAFF, 4-1BB, BCA, SDF-1, MDC, IFN-gamma and TNF-alpha) assessed for association with overall survival (OS) (discovery set). Candidate biomarkers were subsequently assessed in the remaining 273 patients for association with outcomes (validation set). Gene expression signatures were assessed on baseline tissue samples using RNA sequencing.

Results: Five candidate biomarkers, IL-6,IL-7,IL-8,VEGF, and 4-1BB, were significantly associated with OS in the discovery set. We confirmed in the validation set a significant adverse association between OS and higher baseline levels of IL-6, IL-8, VEGF, with respective hazard ratios of 3.17 (95%CI 2.29-4.40), 2.11 (95%CI 1.60-2.80), and 1.36 (95%CI 1.04-1.79). Higher IL-6 and IL-8 levels were associated with an intratumor IMmotion myeloid gene expression signature (p=0.004 and p=0.041 respectively).

Conclusions: Elevated baseline circulating IL-6/IL-8/VEGF are associated with worse outcomes in nivolumab-treated aRCC. Circulating IL-6 and IL-8 showed strongest association with outcomes and correlated with a myeloid tissue contexture, providing guidance for patient selection in future trials.