Purpose To determine the immunologic effects of neoadjuvant chemotherapy plus ipilimumab in early stage non-small cell lung cancer (NSCLC) patients. Experimental Design This is a single-arm chemotherapy plus phased ipilimumab Phase II study of 24 treatment-naïve patients with Stage IB–IIIA NSCLC. Patients received neoadjuvant therapy consisting of 3 cycles of paclitaxel with either cisplatin or carboplatin and ipilimumab included in the last 2 cycles. Results Chemotherapy alone had little effect on immune parameters in PBMCs. Profound CD28 dependent activation of both CD4 and CD8 cells was observed following ipilimumab. Significant increases in the frequencies of CD4+ cells expressing activation markers ICOS, HLA-DR, CTLA-4, and PD-1 were apparent. Likewise, increased frequencies of CD8+ cells expressing the same activation markers, with the exception of PD-1, were observed. We also examined 7 resected tumors and found higher frequencies of activated TILs than those observed in PBMCs. Surprisingly, we found 4 cases of pre-existing tumor-associated antigens (TAA) responses against survivin, PRAME, or MAGE-A3 present in PBMC at baseline, but neither increased frequencies nor the appearance of newly detectable responses following ipilimumab therapy. Ipilimumab had little effect on the frequencies of circulating Tregs and MDSCs. Conclusions This study did not meet the primary endpoint of detecting an increase in blood based tumor associated antigen T cell responses after ipilimumab. Collectively, these results highlight the immune activating properties of ipilimumab in early stage NSCLC. The immune profiling data for ipilimumab alone can contribute to the interpretation of immunological data from combined immune checkpoint blockade immunotherapies.

Existing normative flow cytometry data have several limitations including small sample sizes, incompletely described study populations, variable flow cytometry methodology, and limited depth for defining lymphocyte subpopulations. To overcome these issues, we defined high-dimensional flow cytometry reference ranges for the healthy human immune system using Human Immunology Project Consortium methodologies after carefully screening 127 subjects deemed healthy through clinical and laboratory testing. We enrolled subjects in the following age cohorts: 18-29 years, 30-39, 40-49, and 50-66 and enrolled cohorts to ensure an even gender distribution and at least 30% non-Caucasians. From peripheral blood mononuclear cells, flow cytometry reference ranges were defined for >50 immune subsets including T-cell (activation, maturation, T follicular helper and regulatory T cell), B-cell, and innate cells. We also developed a web tool for visualization of the dataset and download of raw data. This dataset provides the immunology community with a resource to compare and extract data from rigorously characterized healthy subjects across age groups, gender and race.

Morreton virus (MORV) is a novel oncolytic Vesiculovirus, genetically distinct from vesicular stomatitis virus (VSV). we report that MORV induced potent cytopathic effects in a panel of cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) cell lines. In addition, high intranasal doses of MORV were not associated with significant adverse effects and were well tolerated in mice bearing liver tumor xenografts and syngeneic liver cancers. Furthermore, single intratumoral treatments with MORV (1 x 10 7 TCID 50 ) triggered a robust antitumor immune response leading to substantial tumor regression and disease control in a syngeneic CCA model, using 10-fold lower dose compared to VSV (1 x 10 8 TCID 50 ). In addition, MORV and VSV both induced prominent tumor growth delay in immunodeficient mice bearing Hep3B hepatocellular carcinoma (HCC) but not in mice bearing HuCCT-1 CCA xenografts. Our findings indicate that wild-type MORV is safe and can induce potent tumor regression in HCC and CCA animal models without adverse events via immune-mediated and immune-independent mechanisms. Further development and clinical translation of MORV as virotherapy for liver cancers are warranted.

Morreton virus (MORV) is a novel oncolytic Vesiculovirus, genetically distinct from vesicular stomatitis virus (VSV). we report that MORV induced potent cytopathic effects in a panel of cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) cell lines. In addition, high intranasal doses of MORV were not associated with significant adverse effects and were well tolerated in mice bearing liver tumor xenografts and syngeneic liver cancers. Furthermore, single intratumoral treatments with MORV (1 x 107 TCID50) triggered a robust antitumor immune response leading to substantial tumor regression and disease control in a syngeneic CCA model, using 10-fold lower dose compared to VSV (1 x 108 TCID50). In addition, MORV and VSV both induced prominent tumor growth delay in immunodeficient mice bearing Hep3B hepatocellular carcinoma (HCC) but not in mice bearing HuCCT-1 CCA xenografts. Our findings indicate that wild-type MORV is safe and can induce potent tumor regression in HCC and CCA animal models without adverse events via immune-mediated and immune-independent mechanisms. Further development and clinical translation of MORV as virotherapy for liver cancers are warranted.

Background and aims: Biliary tract cancers (BTCs) are uncommon, but highly lethal, gastrointestinal malignancies. Gemcitabine/cisplatin is a standard-of-care systemic therapy, but has a modest impact on survival and harbors toxicities, including myelosuppression, nephropathy, neuropathy, and ototoxicity. Whereas BTCs are characterized by aberrations activating the

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5571 Background: Understanding the immune checkpoint marker repertoire can facilitate development of therapeutic strategies to improve efficacy of immune-based therapies. We used a novel high-dimensional flow cytometry panel to determine co-expression patterns of immune checkpoint markers and effector function of CD8+ T cells from peripheral blood and ascites of patients newly diagnosed with ovarian cancer. Methods: Peripheral blood and ascites samples were collected from patients with epithelial ovarian cancer (n=8). Cells isolated from peripheral blood and ascites were used for immune profiling by multiparameter flow cytometry of 5 inhibitory receptors (PD-1, LAG-3, TIM-3, TIGIT, and BTLA) on CD8+ T cells, along with 4 functional parameters (production of each of the following: TNF-α, IFN-γ, IL-2, and upregulation of CD107a). A complementary multiplex analysis on plasma and ascites fluid was performed to quantify 14 soluble checkpoint markers. Results: The concentrations of soluble PD-1, TIM-3, LAG-3, CTLA-4, BTLA, IDO, and CD137 were increased in ascites fluid compared to plasma from patients with ovarian cancer. Ascites CD8+ T cells co-express higher levels of inhibitory receptors than peripheral CD8+ T cells. In total, CD8+ T cells in ascites retained the ability to produce effector functions at levels similar to peripheral blood. However, IFN-γ production was retained in PD-1 only expressing CD8+ T cells and decreased in CD8+ T cells co-expressing multiple receptors. Conclusions: High-dimensional flow cytometry allowed for the phenotypic and functional characterization of CD8+ T cells from ovarian cancer patients. The profile of receptor co-expression was distinct in peripheral blood compared to ascites. Collectively, our study suggests that co-expression of factors beyond PD-1 influences CD8+ T cell activity. Thus blocking PD-1 and PD-L1 alone may not be sufficient for CD8+ T cells expressing multiple inhibitory receptors.

PURPOSE This investigation sought to evaluate the prognostic value of pretreatment of circulating tumor DNA (ctDNA) in metastatic biliary tract cancers (BTCs) treated with platinum-based first-line chemotherapy treatment. MATERIALS AND METHODS We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis, we considered the detected gene with highest variant allele frequency as the dominant clone allele frequency (DCAF). Results of ctDNA analysis were correlated with patients' demographics, progression-free survival (PFS), and overall survival (OS). RESULTS The median age of patients was 67 (27-90) years. Fifty-four (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma, and six gallbladder cancers. Forty-six (68.6%) of the patients were treated with cisplatin plus gemcitabine, and 16.4% of patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations, whereas 15% of patients were treated on a clinical trial with gemcitabine and cisplatin plus additional agents (CX4945, PEGPH20, or nab-paclitaxel). TP53, KRAS, FGFR2, ARID1A, STK11, and IDH1 were the genes with highest frequency as DCAF. The median DCAF was 3% (0%-97%). DCAF > 3% was associated with worse OS (median OS: 10.8 v 18.8 months, P = .032). Stratifying DCAF in quartiles, DCAF > 10% was significantly related to worse PFS (median PFS: 3 months, P = .014) and worse OS (median OS: 7.0 months, P = .001). Each 1% increase in ctDNA was associated with a hazard ratio of 13.1 in OS when adjusting for subtypes, metastatic sites, size of largest tumor, age, sex, and CA19-9. CONCLUSION DCAF at diagnosis of advanced BTC can stratify patients who have worse outcomes when treated with upfront platinum-based chemotherapy. Each increase in %ctDNA decreases survival probabilities.