The Significance of PARP1 as a biomarker for Predicting the Response to PD-L1 Blockade in Patients with PBRM1-mutated Clear Cell Renal Cell Carcinoma.

Immune checkpoint inhibitors (ICIs) have become key agents in the management of clear cell renal cell carcinoma (ccRCC), but their benefits are limited and responders remain unidentified. We investigated the significance of PARP1 in ccRCC using RNA sequencing data for 311 tumors from patients enrolled in prospective clinical trials of PD-1 blockade. Among patients treated with nivolumab (n = 181), overall survival (OS) was significantly higher in the PARP1-low group than in the PARP1-high group (p = 0.006), and PARP1 status was significantly associated with OS (hazard ratio [HR] 1.7; p = 0.007). By contrast, for patients treated with everolimus (n = 130) there was no significant difference by PARP1 status for progression-free survival (PFS; p = 0.9) or OS (p = 0.38). In subgroup analysis for PBRM1-mutated ccRCC, PFS (p = 0.016) and OS (p = 0.004) were significantly longer in the group with PARP1-low status and PBRM1 mutation in comparison to the other groups. In addition, PARP1 status was significantly associated with PFS (HR 2.6; p = 0.007) and OS (HR 3.5; p = 0.016) among patients with PBRM1-mutated ccRCC treated with nivolumab. Our study suggests that PARP1 can be used as a biomarker for predicting response to ICI treatment for patients with PBRM1-mutated ccRCC. PATIENT SUMMARY: Immune checkpoint inhibitors (ICIs) are key agents in the treatment of multiple cancers. We found that expression of the PARP1 protein was associated with survival after ICI treatment and with the response to ICI treatment in patients with clear cell kidney cancer who have a mutation of the PBRM1 gene.

Hagiwara M ，Fushimi A ，Matsumoto K ，Oya M ... -  《-》

PBRM1 mutation and WDR72 expression as potential combinatorial biomarker for predicting the response to Nivolumab in patients with ccRCC: a tumor marker prognostic study.

Chang Q ，Sun J ，Zhao S ，Li L ，Zhang N ，Yan L ，Fan Y ，Liu J ... -  《Aging-US》

Re: Masayuki Hagiwara, Atsushi Fushimi, Kazuhiro Matsumoto, Mototsugu Oya. The Significance of PARP1 as a Biomarker for Predicting the Response to PD-L1 Blockade in Patients with PBRM1-mutated Clear Cell Renal Cell Carcinoma. Eur Urol. 2022;81:145-8.

Wang Z ，Zhao Y ，Zhang Y 《-》

Characterization of tumor mutation burden, PD-L1 and DNA repair genes to assess relationship to immune checkpoint inhibitors response in metastatic renal cell carcinoma.

Immune checkpoint inhibitors (ICIs) have expanded treatment options for metastatic renal cell carcinoma (mRCC); however, there are limited predictive biomarkers for response to ICIs in this indication, with programmed death-ligand 1 (PD-L1) status demonstrating little predictive utility in mRCC. While predictive of ICI response in other tumor types, the utility of tumor mutation burden (TMB) in mRCC is unclear. Here, we assess TMB, loss of antigen presentation genes and PD-L1 status correlated with outcomes to ICI treatment in mRCC. Tumor samples from 34 patients with mRCC treated with ICI therapy at Duke Cancer Institute were retrospectively evaluated using Personal Genome Diagnostics elio tissue complete (RUO version), a tumor genomic profiling assay for somatic variants, TMB, microsatellite status and genomic status of antigen presentation genes. Tumor samples were also analyzed with the Dako 28-8 PD-L1 immunohistochemistry assay. Deidentified clinical information was extracted from the medical record, and tumor response was evaluated based on the Response Evaluation Criteria In Solid Tumors (RECIST) V.1.1 criteria. Patients were stratified by overall response following ICI therapy and designated as progressive disease (PD; n=18) or disease control groups (DC; n=16). TMB scores ranged from 0.36 to 12.24 mutations/Mb (mean 2.83 mutations/Mb) with no significant difference between the PD and DC groups (3.01 vs 2.63 mutations/Mb, respectively; p=0.7682). Interestingly, 33% of PD patients displayed loss of heterozygosity of major histocompatibility complex class I genes (LOH-MHC) vs 6% of DC patients. Nine of 34 samples were PD-L1-positive (4 in the PD group; 5 in the DC group), suggesting no correlation between PD-L1 expression and response to ICI therapy. Notably, the DC group displayed an enrichment of mutations in DNA repair genes (p=0.04), with 68.8% exhibiting at least one mutated homologous recombination repair (HRR)-related gene compared with only 38.9% of the PD group (p=0.03). Overall, neither TMB nor PD-L1 correlated with ICI response and TMB was not significantly associated with PD-L1 expression. The higher incidence of LOH-MHC in PD group suggests that loss of antigen presentation may restrict response to ICIs. Separately, enrichment of HRR gene mutations in the DC group suggests potential utility in predicting ICI response and a potential therapeutic target, warranting future studies.

Labriola MK ，Zhu J ，Gupta RT ，McCall S ，Jackson J ，Kong EF ，White JR ，Cerqueira G ，Gerding K ，Simmons JK ，George D ，Zhang T ... -  《Journal for ImmunoTherapy of Cancer》

Transcriptomic Correlates of Tumor Cell PD-L1 Expression and Response to Nivolumab Monotherapy in Metastatic Clear Cell Renal Cell Carcinoma.

PD-L1 expression on tumor cells (TC) is associated with response to anti-PD-1-based therapies in some tumor types, but its significance in clear cell renal cell carcinoma (ccRCC) is uncertain. We leveraged tumor heterogeneity to identify molecular correlates of TC PD-L1 expression in ccRCC and assessed their role in predicting response to anti-PD-1 monotherapy. RNA sequencing was performed on paired TC PD-L1 positive and negative areas isolated from eight ccRCC tumors and transcriptomic features associated with PD-L1 status were identified. A cohort of 232 patients with metastatic ccRCC from the randomized CheckMate-025 (CM-025) trial was used to confirm the findings and correlate transcriptomic profiles with clinical outcomes. In both the paired samples and the CM-025 cohort, TC PD-L1 expression was associated with combined overexpression of immune- and cell proliferation-related pathways, upregulation of T-cell activation signatures, and increased tumor-infiltrating immune cells. In the CM-025 cohort, TC PD-L1 expression was not associated with clinical outcomes. A molecular RCC subtype characterized by combined overexpression of immune- and cell proliferation-related pathways (previously defined by unsupervised clustering of transcriptomic data) was enriched in TC PD-L1 positive tumors and displayed longer progression-free survival (HR, 0.32; 95% confidence interval, 0.13-0.83) and higher objective response rate (30% vs. 0%, P = 0.04) on nivolumab compared with everolimus. Both TC-extrinsic (immune-related) and TC-intrinsic (cell proliferation-related) mechanisms are likely intertwined in the regulation of TC PD-L1 expression in ccRCC. The quantitation of these transcriptional programs may better predict benefit from anti-PD-1-based therapy compared with TC PD-L1 expression alone in ccRCC.

Denize T ，Hou Y ，Pignon JC ，Walton E ，West DJ ，Freeman GJ ，Braun DA ，Wu CJ ，Gupta S ，Motzer RJ ，Atkins MB ，McDermott D ，Choueiri TK ，Shukla SA ，Signoretti S ... -  《-》