Search

Background Adenoid cystic carcinoma (ACC) is a rare type of cancer commonly occurring in salivary glands. It is characterized by slow but infiltrative growth, nerve infiltration and overall poor prognosis, with late recurrence and distant metastasis. The treatment of ACC is still limited to surgery and/or (adjuvant) radiotherapy. Till now no promising systemic therapy option exists. However, various studies deliver promising results after treatment with anti-angiogenetic agents, such as anti-EGFR-antibody Cetuximab or Tyrosinkinase inhibitor Lenvatinib. Methods By using of immunohistological methods we analyzed and compared the macrophage and lymphocyte populations, vascularization, and PD-L1-status in 12 ACC of the salivary glands. Results All cases showed a significant elevation of macrophages with M2 polarization and a higher vascularization in ACC compared to normal salivary gland tissue. The CD4/CD8 quotient was heterogenous. ACC does not show relevant PD-L1 expression. Conclusions The predominant M2 polarization of macrophages in ACC could be responsible for elevated vascularization, as already been proved in other cancer types, that M2 macrophages promote angiogenesis.

Simple Summary Here, we examined the presence and clinical relevance of A20 in oral squamous cell carcinoma (OSCC). Using a tissue microarray (TMA), immunohistochemical A20 expression as well as tumor-infiltrating lymphocytes (TIL) were analyzed. Hereby, A20 expression was significantly increased in TILs and patients with elevated A20 expression in stromal CD3+ cells showed ameliorated survival in uni- as well as multivariable analyses. Abstract A20, known as a potent inhibitor of NF-κB signaling, has been characterized in numerous clinical as well as preclinical studies. Recently, especially in various malignant diseases, the prognostic and therapeutic relevance of A20 was investigated. In oral squamous cell carcinoma (OSCC) however, the characterization of A20 is uncharted territory. We analyzed a tissue microarray (TMA) of 229 surgically-treated OSCC patients (2003–2013). Immunohistochemical (IHC) stainings were performed for A20 and CD3; additionally, standard haematoxylin-eosin staining was applied. IHC findings were correlated with a comprehensive dataset, comprising clinical and pathohistological information. A20 expression was analyzed in tumor cells as well as in tumor infiltrating lymphocytes (TILs) and correlated with the overall survival (OS) and recurrence-free survival (RFS) using uni- and multivariable Cox regression. The median follow-up time was 10.9 years and the A20 expression was significantly decreased in CD3+ TILs compared to mucosa-infiltrating lymphocytes (MILs). In the Kaplan–Meier analyses, higher A20 expression in TILs was correlated with better OS (p = 0.017) and RFS (p = 0.020). In the multivariable survival analysis, A20 overexpression correlated with improved OS (HR: 0.582; 95% CI 0.388–0.873, p = 0.009) and RFS (HR 0.605; 95% CI 0.411–0.889, p = 0.011). Our results indicate a novel prognostic role for A20 in OSCC. Due to its elevated expression in TILs, further research is highly desirable, which therefore could offer new therapeutic opportunities for patients suffering from OSCC.

In patients with melanoma brain metastases (MBM), a combination of radiotherapy (RT) with immune checkpoint inhibitors (ICI) is routinely used. However, the best sequence of radio-immunotherapy (RIT) remains unclear. In an exploratory phase 2 trial, MBM patients received RT (stereotactic or whole-brain radiotherapy depending on the number of MBM) combined with ipilimumab (ipi) ± nivolumab (nivo) in different sequencing (Rad-ICI or ICI-Rad). Comparators arms included patients treated with ipi-free systemic treatment or without RT (in MBM-free patients). The primary endpoints were radiological and immunological responses in the peripheral blood. Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Of 106 screened, 92 patients were included in the study. Multivariate analysis revealed an advantage for patients starting with RT (Rad-ICI) for overall response rate (RR: p = .007; HR: 7.88 (95%CI: 1.76-35.27)) and disease control rate (DCR: p = .036; HR: 6.26 (95%CI: 1.13-34.71)) with a trend for a better PFS (p = .162; HR: 1.64 (95%CI: 0.8-3.3)). After RT plus two cycles of ipi-based ICI in both RIT sequences, increased frequencies of activated CD4, CD8 T cells and an increase in melanoma-specific T cell responses were observed in the peripheral blood. Lasso regression analysis revealed a significant clinical benefit for patients treated with Rad-ICI sequence and immunological features, including high frequencies of memory T cells and activated CD8 T cells in the blood. This study supports increasing evidence that sequencing RT followed by ICI treatment may have better effects on the immunological responses and clinical outcomes in MBM patients.

Supplemental Methods. (DOCX 85Â kb)

Comparative analysis of the cellular composition of location-specific groups I–IV in the microarray discovery set (n = 36 GBMs). ANOVA analyses revealed no significant difference in all four comparisons. Difference of (A) tumor content determined by neuropathologist in hematoxylin and eosin (HE) stain, (B) StromalScore, (C) ImmuneScore, and (D) ESTIMATEScore between location groups. StromalScore, ImmuneScore, and ESTIMATEScore were calculated using the estimate package for the R software environment (Kosuke Yoshihara, Hoon Kim, and Roel GW Verhaak (2013), ESTIMATE Estimate of STromal and Immune cells in MAlignant Tumor tissues using Expression data, R package version 1.0.11). (DOCX 70 kb)

CEACAM6 (CD66c) was previously shown to act as a novel immune checkpoint regulator suppressing the activity of effector T cells against tumors (Witzens-Harig et al., Blood 2013). CEACAM6 is a GPI-linked protein that is strongly expressed at the tumor cell surface in multiple cancer indications such as non-small cell lung adenocarcinoma (NSCLC), colorectal carcinoma (CRC), gastric adenocarcinoma and pancreatic cancer. In general, elevated CEACAM6 expression is associated with advanced tumor stages and poor prognosis. In vitro experiments showed that engagement of T-cells with CEACAM6, either expressed on tumor cells or presented on beads, resulted in suppression of TCR-mediated T-cell activation and ZAP70 phosphorylation. Based on these findings, we hypothesized that antibodies targeting CEACAM6 may be employed to enhance T-cell responses against CEACAM6-expressing cancers. Here we report the generation and characterization of BAY 1834942, a humanized monoclonal antibody selectively blocking the inhibitory impact of CEACAM6 on human T cells. There is no rodent ortholog of CEACAM6 precluding in vivo efficacy studies. In tumor cell / T cell co-culture systems, BAY 1834942 increased secretion of T-cell cytokines and effector molecules (e.g. IFNγ, TNFα, IL-2, granzyme B) and resulted in improved tumor cell killing. The effects of BAY 1834942 were dose-dependent, only observed in the context of CEACAM6-expressing tumor cells and could be reproduced in experiments using tumor cell lines and T-cell preparations from different sources, including T cells derived from tumor infiltrating lymphocytes from pancreatic cancer. BAY 1834942 is cross-reactive with the cynomolgus CEACAM6 ortholog and was well-tolerated in monkey toxicology studies. In summary, BAY 1834942 is a novel checkpoint inhibitor with potential for the treatment of patients with CEACAM6 expressing cancers, both as single agent and in combination with other checkpoint inhibitors. First-in-man trials are expected to commence in 2018. Citation Format: Joerg Willuda, Mark Trautwein, Jessica Pinkert, Wolf-Dietrich Doecke, Hans-Henning Boehm, Florian Wessel, Yingzi Ge, Eva Maria Gutierrez, Joerg Weiske, Christoph Freiberg, Uwe Gritzan, Julian Glueck, Dieter Zopf, Sven Golfier, Oliver von Ahsen, Ruprecht Zierz, Sabine Wittemer-Rump, Heiner Apeler, Ziegelbauer Karl, Rienk Offringa, Bertolt Kreft, Beckhove Philipp. BAY 1834942 is an immunotherapeutic antibody blocking the novel immune checkpoint regulator CEACAM6 (CD66c) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1771.

Significant progress has been achieved recently in cancer vaccines that aim at engaging or reengaging the tumor immunity, in particular in the rapidly growing field of personalized immunotherapy. Yet novel immunization solutions to deliver efficiently tumor-associated (neo)antigens to professional antigen-presenting cells, and to overcome the peripheral tolerance and the immunosuppressive tumor microenvironment that prevent the eradication of cancer in most patients, are urgently needed. VAXIMM is developing a unique and versatile oral T-cell vaccination platform based on the FDA-approved live-attenuated Salmonella Typhi strain Ty21a vaccine Vivotif®, capable of delivering tumor-associated antigens encoded in DNA expression construct to the gut-associated lymphoid tissue, breaking immune tolerance and inducing antitumor immunity. This study summarizes the immunogenicity and antileukemia efficacy of VXM10 vaccines based on the live-attenuated Salmonella Typhimurium strain SL7207, transformed with a eukaryotic expression plasmid encoding the murine programmed death-ligand 1 (PD-L1) protein. It also describes for the first time the systemic immunogenicity of Salmonella Typhimurium-based polyepitope oral vaccines in healthy animals. The antileukemia activity of VXM10 was evaluated in the FBL-3 disseminated model of leukemia, in which the tumor cells express high levels of PD-L1. Multiple oral administrations of VXM10 used at 1010 colony-forming units (CFU) were generally well tolerated, and neither sign of toxicity nor body weight loss were observed throughout the study. Oral administration of VXM10 produced a strong antitumor effect in the FBL-3 leukemia model, with 100% of surviving animals 80 days after leukemia challenge in the highest-dose groups. In contrast, administration of the empty vector control did not show any anticancer effect. Moreover, 100% of long-term surviving mice resisted rechallenge with FBL-3 cells, demonstrating that vaccination with VXM10 generated a potent memory T-cell response against the leukemia. Importantly, full leukemia control was achieved in both prophylactic and therapeutic settings. Immunogenicity and antibody response towards PD-L1 are being evaluated to dissect the exact mechanism of action of these novel vaccines. Finally, different polyepitope vaccines encoding dominant epitopes from VEGFR2, Mesothelin, WT1, CEA, and Ovalbumin induced a significant systemic immunogenicity for up to 6 out of 9 epitopes, 10 days after vaccination of healthy C57BL/6J mice via the oral route, with doses up to 1010 CFU, as measured in the spleen by flow cytometry using peptide-MHC class I pentamers. This study provides further evidence that VAXIMM’s oral T-cell vaccination platform can be employed to stimulate antitumor immunity against antigens of the immune checkpoint regulatory protein PD-L1, and also against T-cell antigens encoded by polyepitope constructs. These data pave the way for advancing the development of VXM10 and neoantigen-based vaccines into clinical development. Citation Format: Sébastien Wieckowski, Lilli Podola, Marco Springer, Iris Kobl, Heiko Smetak, Anne-Lucie Nugues, Philippe Slos, Amine Adda Berkane, Ming Wei, Klaus Breiner, Albrecht Meichle, Beckhove Philipp, Marc Mansour, Matthias Schroff, Heinz Lubenau. Live attenuated oral Salmonella platform for effective targeting of multiple tumor-associated epitopes and PD-L1 [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B196.