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BackgroundThe phase II NIVOREN GETUG-AFU 26 study reported safety and efficacy of nivolumab in patients with metastatic clear cell renal cell carcinoma (m-ccRCC) in a ‘real-world setting’. We conducted a translational-research program to determine whether specific circulating immune-cell populations and/or soluble factors at baseline were predictive of clinical outcomes in patients with m-ccRCC treated with nivolumab within the NIVOREN study.MethodsAbsolute numbers of 106 circulating immune-cell populations were prospectively analyzed in patients treated at a single institution within the NIVOREN trial with available fresh-whole-blood, using dry formulation panels for multicolor flow cytometry. In addition, a panel of 14 predefined soluble factors was quantified for each baseline plasma sample using the Meso-Scale-Discovery immunoassay. The remaining patients with available plasma sample were used as a validation cohort for the soluble factor quantification analysis. Tumor immune microenvironment characterization of all patients included in the translational program of the study was available. The association of blood and tissue-based biomarkers, with overall survival (OS), progression-free survival (PFS) and response was analyzed.ResultsAmong the 44 patients, baseline unswitched memory B cells (NSwM B cells) were enriched in responders (p=0.006) and associated with improved OS (HR=0.08, p=0.002) and PFS (HR=0.54, p=0.048). Responders were enriched in circulating T follicular helper (Tfh) (p=0.027) and tertiary lymphoid structures (TLS) (p=0.043). Circulating NSwM B cells positively correlated with Tfh (r=0.70, pConclusionWe report the first fresh blood immune-monitoring of patients with m-ccRCC treated with nivolumab. Baseline blood concentration of NSwM B cells was associated to response, PFS and OS in patients with m-ccRCC treated with nivolumab. BCA-1/CXCL13 and BAFF, inversely correlated to NSwM B cells, were both associated with worse OS in discovery and validation cohorts. Our data confirms a role for B cell subsets in the response to immune checkpoint blockade therapy in patients with m-ccRCC. Further studies are needed to confirm these findings.

A high density of tumor-infiltrating CD8+ T lymphocytes (CTLs), key mediator of anticancer immunity, and CD20+ B cells correlates with positive prognostic value and prolonged survival in patients with a various solid tumors including high-grade serous ovarian carcinoma (HGSC). The majority of HGSCs containing high frequencies of CD8+ CTLs are also robustly infiltrated by CD20+ B cells, and patients whose tumors exhibit abundant coinfiltration have higher survival rates than patients with tumors that only contain high amounts of CD8+ CTLs. However, the cellular mechanism, the potential impact of mature dendritic cells (DCs) in shaping the immune contexture of HGSC, their role in the establishment of T cell-dependent antitumor immunity, and their potential prognostic value for HGSC patients remain unclear. Three independent cohorts of patients with resectable HGSC who did not receive neoadjuvant chemotherapy were involved in the study. Lysosomal-associated membrane protein 3 (DC-LAMP) and its colocalization with CD20+B cells in samples was analyzed by immunohistochemistry (IHC) and cell quantification. Prognostic impact of DC-LAMP+ cells in patient cohort was stratified based on median density of DC-LAMP+ cells in the tumor stroma and nest, followed by retrospective RFS and OS analysis. Comparison of DC-LAMPHi and DC-LAMPLo patients and impact of mature DCs on the composition of the immune contexture characterized by TH1 polarization and cytotoxic activity was performed by biomolecular analyses (flow cytometry, NGS analysis). Patients with high density of DC-LAMP+ cells in the tumor stroma exhibited significantly longer RFS and OS than DC-LAMP- patients. Compared to DC-LAMPLo, DC-LAMPHi tumors exhibited an over-representation of gene sets specifically clustering to the following immunologic functions: T cells, CD8 cytotoxicity, TH1 polarization, T cell activation, NK cells, and plasma cells. Also, a significantly higher percentage of CD3+CD45+ and CD3+CD8+ T cells among live mononuclear cells and higher density of NK cells in the tumor stroma in DC-LAMPHi were observed. We found that both mature DCs and CD20+ B cells play a critical role in the generation of a clinically favorable cytotoxic immune response in HGSC microenvironment. Robust tumor infiltration by both DC-LAMP+ DCs and CD20+ B cells was associated with most favorable overall survival in independent cohorts of chemotherapy-naive HGSC patients. Our findings suggest that the presence of mature, DC-LAMP+ DCs in the tumor microenvironment may represent a novel, powerful prognostic biomarker for HGSC patients that reflects the activation of clinically relevant anticancer immunity. Citation Format: Iva Truxova, Lenka Kasikova, Michal Hensler, Petr Skapa, Jan Laco, Ladislav Pecen, Lucie Belicova, Sarka Vosahlikova, Ivan Praznovec, Michael Halaska, Tomas Brtnicky, Eva Salkova, Lukas Rob, Roman Kodet, Jeremy Goc, Catherine Sautes-Fridman, Wolf Herve Fridman, Ales Ryska, Lorenzo Galluzzi, Radek Spisek, Jitka Fucikova. Mature dendritic cells correlate with favorable immune infiltrate and improved prognosis in ovarian carcinoma patients [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A24.

Twenty-seven subjects with squamous cell cancer of the head and neck received the neoadjuvant IRX-2 immunotherapy regimen prior to surgery in a Phase 2 trial. Pretreatment tumor biopsies were compared with the primary tumor surgical specimens for lymphocyte infiltration, necrosis and fibrosis, using hematoxylin and eosin stain and immunohistochemistry in 25 subjects. Sections were examined by three pathologists. Relative to pretreatment biopsies, increases in lymphocyte infiltration (LI) were seen using H and E or immunohistochemistry. CD3+ CD4+ T cells and CD20+ B cells were primarily found in the peritumoral stroma and CD3+ CD8+ T cells and CD68+ macrophages were mainly intratumoral. LI in the surgical specimens were associated with reductions in the primary tumor size. Improved survival at 5 years was correlated with high overall LI in the tumor specimens. Neoadjuvant IRX-2 immunotherapy regimen may restore immune responsiveness presumably by mobilizing tumor infiltrating effector lymphocytes and macrophages into the tumor.

Regulatory T cells (Tregs) exert various suppressive mechanisms to dampen the host immune response which can help tumor cells to escape immune surveillance. However, the prognostic value of tumor-infiltrating Tregs (Ti-Tregs) is controversial based on the expression of FoxP3 marker in cancer patients. Here, we decipher the phenotype of Tregs infiltrating human lung cancer to determine their role in shaping the immune response against tumor cells. Our aim was to study the differentiation, activation, and immunosuppression status of Ti-Tregs in different areas of human lung tumors. Immunohistochemistry was performed on paraffin-embedded tissue sections for CD3 and FoxP3 stainings, and phenotypic analysis was carried out on fresh human lung cancer specimens (n=50) by flow cytometry. In lung cancer patients, Ti-Tregs localize in the different part of the tumor i.e. tumor nests, stroma, and tertiary lymphoid structures (TLS). Ti-Tregs are CD4+ and show central-memory and effector-memory phenotype. Interestingly, Ti-Tregs exhibit different phenotypes based on the differential expression of activation and immunosuppression molecules. In conclusion, the presence of several Ti-Treg subsets in lung tumor suggests that they may play different roles in distinct tumor areas. Thus, the next step will be to decipher the mechanisms and functions used by these Treg populations in order to manipulate them for therapeutic intervention.