Purpose: We sought to validate levels of CD8 tumor-infiltrating cells (TIC) expressing PD-1 but not TIM-3 and LAG-3 (IF biomarker; Pignon and colleagues, 2019) and to investigate human endogenous retroviruses (hERV) as predictors of response to anti-PD-1 in a randomized trial of nivolumab (nivo) versus everolimus (evero) in patients with metastatic clear cell renal cell carcinoma (mccRCC; CheckMate-025).
Experimental Design: Tumor tissues (nivo: = 116, evero: = 107) were analyzed by multiparametric immunofluorescence (IF) and qRT-PCR. Genomic/transcriptomic analyses were performed in a subset of samples.