Immune checkpoint inhibitors targeting the programmed cell death-1 receptor (PD-1) improve survival in a subset of patients with clear cell renal cell carcinoma (ccRCC). To identify genomic alterations in ccRCC that correlate with response to anti-PD-1 monotherapy, we performed whole exome sequencing of metastatic ccRCC from 35 patients. We found that clinical benefit was associated with loss-of-function mutations in the PBRM1 gene (p=0.012), which encodes a subunit of a SWI/SNF chromatin remodeling complex (the PBAF subtype). We confirmed this finding in an independent validation cohort of 63 ccRCC patients treated with PD-(L)1 blockade therapy alone or in combination with anti-CTLA-4 therapies (p=0.0071). Gene expression analysis of PBAF-deficient ccRCC cell lines and PBRM1-deficient tumors revealed altered transcriptional output in JAK/STAT, hypoxia, and immune signaling pathways. PBRM1 loss in ccRCC may alter global tumor cell expression profiles to influence responsiveness to immune checkpoint therapy.

Immune-related adverse events (irAEs) have been described with immune checkpoint inhibitors (ICIs), but the incidence and relative risk (RR) of irAEs associated with these drugs remains unclear. We selected five key irAEs from treatments with approved cytotoxic T-lymphocyte–associated protein 4 (CTLA-4), programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors (ipilimumab, nivolumab or pembrolizumab, and atezolizumab, respectively) to better characterize their safety profile. We performed a meta-analysis of randomized phase II/III immunotherapy trials, with non-ICI control arms, conducted between 1996 and 2016. We calculated the incidence and RR of selected all-grade and high-grade gastrointestinal, liver, skin, endocrine, and pulmonary irAEs across the trials using random-effect models. Twenty-one trials were included, totaling 11,454 patients, of whom 6528 received an ICI (nivolumab, 1534; pembrolizumab, 1522; atezolizumab, 751; and ipilimumab, 2721) and 4926 had not. Compared to non-ICI arms, ICIs were associated with more all-grade colitis (RR 7.66, P < 0.001), aspartate aminotransferase (AST) elevation (RR 1.80; P = 0.020), rash (RR 2.50; P = 0.001), hypothyroidism (RR 6.81; P < 0.001), and pneumonitis (RR 4.14; P = 0.012). Rates of high-grade colitis (RR 5.85; P < 0.001) and AST elevation (RR 2.79; P = 0.014) were higher in the ICI arms. Ipilimumab was associated with a higher risk of all-grade rash (P = 0.006) and high-grade colitis (P = 0.021) compared to PD-1/PD-L1 ICIs. Incidence of fatal irAE was < 1%. This meta-analysis offers substantial evidence that ICIs are associated with a small but significant increase in risk of selected all-grade irAEs and high-grade gastrointestinal and liver toxicities. Although fatal irAEs remain rare, AEs should be recognized promptly as early interventions may alleviate future complications.

BackgroundAn elevated Neutrophil-to-lymphocyte ratio (NLR) is associated with worse outcomes in several malignancies. However, its role with contemporary immune checkpoint blockade (ICB) is unknown. We investigated the utility of NLR in metastatic renal cell carcinoma (mRCC) patients treated with PD-1/PD-L1 ICB.MethodsWe examined NLR at baseline and 6 (±2) weeks later in 142 patients treated between 2009 and 2017 at Dana-Farber Cancer Institute (Boston, USA). Landmark analysis at 6 weeks was conducted to explore the prognostic value of relative NLR change on overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Cox and logistic regression models allowed for adjustment of line of therapy, number of IMDC risk factors, histology and baseline NLR.ResultsMedian follow up was 16.6 months (range: 0.7–67.8). Median duration on therapy was 5.1 months (<1–61.4). IMDC risk groups were: 18% favorable, 60% intermediate, 23% poor-risk. Forty-four percent were on first-line ICB and 56% on 2nd line or more. Median NLR was 3.9 (1.3–42.4) at baseline and 4.1 (1.1–96.4) at week 6. Patients with a higher baseline NLR showed a trend toward lower ORR, shorter PFS, and shorter OS. Higher NLR at 6 weeks was a significantly stronger predictor of all three outcomes than baseline NLR. Relative NLR change by ≥25% from baseline to 6 weeks after ICB therapy was associated with reduced ORR and an independent prognostic factor for PFS (p < 0.001) and OS (p = 0.004), whereas a decrease in NLR by ≥25% was associated with improved outcomes.ConclusionsEarly decline and NLR at 6 weeks are associated with significantly improved outcomes in mRCC patients treated with ICB. The prognostic value of the readily-available NLR warrants larger, prospective validation.

Despite remarkable success of immune checkpoint inhibitors, the majority of cancer patients have yet to receive durable benefits. Here, in order to investigate the metabolic alterations in response to immune checkpoint blockade, we comprehensively profile serum metabolites in advanced melanoma and renal cell carcinoma patients treated with nivolumab, an antibody against programmed cell death protein 1 (PD1). We identify serum kynurenine/tryptophan ratio increases as an adaptive resistance mechanism associated with worse overall survival. This advocates for patient stratification and metabolic monitoring in immunotherapy clinical trials including those combining PD1 blockade with indoleamine 2,3-dioxygenase/tryptophan 2,3-dioxygenase   (IDO/TDO) inhibitors.