Entinostat, nivolumab and ipilimumab for women with advanced HER2-negative breast cancer: a phase Ib trial

We report the results of 24 women, 50% (N = 12) with hormone receptor-positive breast cancer and 50% (N = 12) with advanced triple-negative breast cancer, treated with entinostat + nivolumab + ipilimumab from the dose escalation (N = 6) and expansion cohort (N = 18) of ETCTN-9844 ( NCT02453620 ). The primary endpoint was safety. Secondary endpoints were overall response rate, clinical benefit rate, progression-free survival and change in tumor CD8:FoxP3 ratio. There were no dose-limiting toxicities. Among evaluable participants (N = 20), the overall response rate was 25% (N = 5), with 40% (N = 4) in triple-negative breast cancer and 10% (N = 1) in hormone receptor-positive breast cancer. The clinical benefit rate was 40% (N = 8), and progression-free survival at 6 months was 50%. Exploratory analyses revealed that changes in myeloid cells may contribute to responses; however, no correlation was noted between changes in CD8:FoxP3 ratio, PD-L1 status and tumor mutational burden and response. These findings support further investigation of this treatment in a phase II trial.

From bench to bedside: Single-cell analysis for cancer immunotherapy

Single-cell technologies are emerging as powerful tools for cancer research. These technologies characterize the molecular state of each cell within a tumor, enabling new exploration of tumor heterogeneity, microenvironment cell-type composition, and cell state transitions that affect therapeutic response, particularly in the context of immunotherapy. Analyzing clinical samples has great promise for precision medicine but is technically challenging. Successfully identifying predictors of response requires well-coordinated, multi-disciplinary teams to ensure adequate sample processing for high-quality data generation and computational analysis for data interpretation. Here, we review current approaches to sample processing and computational analysis regarding their application to translational cancer immunotherapy research.

Abstract 1682: Imaging mass cytometry reveals key spatial features among immune cells in hepatocellular carcinomas treated with neoadjuvant cabozantinib and nivolumab

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and carries a poor prognosis. Most HCC is unresectable at presentation, and until recently, the use of perioperative systemic therapy has been hampered by a lack of any effective therapies. We recently conducted a single-arm trial of neoadjuvant cabozantinib followed by nivolumab for borderline resectable or locally advanced HCC (NCT03299946), through which secondary resectability was obtained in a subset of patients. Of 15 patients enrolled, 12/15 patients achieved margin-negative resection, and 5/12 resected patients experienced a major or complete pathologic response. Here we characterize changes in the tumor microenvironment (TME) induced by neoadjuvant therapy. We constructed a tissue microarray containing 37 core liver biopsies (15 from responders, 22 from nonresponders), stained with a 27-marker panel, and used ilastik and CellProfiler to segment the resulting images, producing a single-cell dataset comprising 59,453 cells. We then used FlowSOM to perform unbiased clustering of cells, which we annotated into 17 cell types. Next, we performed spatial analysis using Voronoi diagrams and top neighbors mapping. We generated a minimum spanning tree using shortest Euclidean distances to model the simplest spatial relationships among all cell types and ranked their importance using random forest models. Grossly, responder cores were characterized by the presence of tertiary lymphoid aggregates, as well as a higher percent abundance of several immune cell types, including CD4 T (p < 0.05) and CD8 T cells (p < 0.005). In responders, Voronoi diagrams revealed denser packing of most immune cell types, particularly B cells (p < 0.005), and top neighbors analysis indicated higher numbers of lymphoid-lymphoid, myeloid-myeloid, and lymphoid-myeloid neighbors. This suggests that response is characterized by immune infiltration of the TME. Exploring this further, a minimum spanning tree showed that in nonresponders, CD8 T cells were flanked by CD163+ macrophages, whereas in responders, HCC cells were closely linked to lymphoid cells. Importance plots from random forest models for B, CD4 T, and CD8 T cells revealed that top predictors of responder status were higher minimum distance from CD163+ Arg1+ macrophages and lower minimum distance from CD163+ Ki67+ macrophages, which express higher levels of PD-L1. This suggests that proximity of B and T cells to macrophages that exert immunosuppression via Arg1 is a critical feature of resistance to cabozantinib plus nivolumab, whereas proximity to proliferative macrophages that express higher levels of PD-L1 is a key feature of response. In conclusion, cabozantinib and nivolumab can effectively promote antitumor immunity by altering both the abundance and spatial organization of macrophages, B cells, and T cells in the HCC TME.

Citation Format: Shu Zhang, Qingfeng Zhu, Nicole Gross, Soren Charmsaz, Atul Deshpande, Stephanie Xavier, Aditya Mohan, James Leatherman, Guanglan Mo, Jennifer Durham, Aleksandra Popovic, Brad Wilt, Dongxia Lin, Derek Quong, Robert Anders, Elana Fertig, Elizabeth M. Jaffee, Mark Yarchoan, Won J. Ho. Imaging mass cytometry reveals key spatial features among immune cells in hepatocellular carcinomas treated with neoadjuvant cabozantinib and nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1682.

Abstract 4475: Site-specific profiling of TCR signaling

Background: T cell exhaustion is a hyporesponsive state commonly found in cancer and is characterized by overexpression of inhibitory receptors and secretion of immunosuppressive cytokines. Immune checkpoint inhibitors (ICIs) target inhibitory receptors such as PD-1 and CTLA-4 to reinvigorate exhausted T cells and promote anti-tumor responses. While ICIs have improved clinical outcomes, no biomarker to date reliably determines the extent of T cell exhaustion. Since robust T cell receptor (TCR) signaling is critical for effective antitumor immunity, we hypothesized that interrogating the phospho-signaling states within the T cells along with their functional states will enhance our understanding of T cell exhaustion and yield potential biomarkers.

Methods: In this study, we developed a validated mass cytometry panel of 24 markers to quantify phosphorylation states of 8 intracellular kinases involved in the TCR signaling within multiple CD8+ T cell subtypes. To identify potential differences between the local and peripheral immunological responses, we profiled CD8+ T cells derived from four sites (tumor, tumor draining lymph node, spleen and peripheral blood) in mice bearing MC38-induced flank tumors. We performed a clustering analysis of the dataset in aggregate using FlowSOM and visualized the results with UMAP, a dimensionality reduction algorithm, to compare the phospho-profiles of CD8+ T cell subtypes in all four sites.

Results: Bulk analysis of CD8+ T cells demonstrates site-specific concordance between phosphoprotein markers and T cell functional markers (i.e. Ki67 and Granzyme B) with the highest expression in tumor followed by tumor draining lymph node, spleen and peripheral blood. Based on the results from the clustering analysis, site-specific breakdown of CD8+ T cells revealed high prevalence of effector, memory, and exhausted memory T cells in tumors compared to other sites where naïve T cells predominated. Despite these variations in CD8+ T cell immunophenotypic distribution, TCR signaling profiles correlated strongly with specific T cell subtypes across all sites.

Conclusion: These data demonstrate that subtype-specific TCR signaling is preserved systemically and that phospho-immune subtyping of CD8+ T cells in the peripheral blood may be used to identify T cell exhaustion states that are found in the tumor microenvironment. Further studies will be conducted to investigate the changes in the TCR phospho-profiles in response to ICI treatment and their associated functions.

Citation Format: Zaw Phyo, Rohan Verma, Won J. Ho, Elizabeth M. Jaffee. Site-specific profiling of TCR signaling [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4475.

Understanding the diagnostic yield of current endoscopic biopsy for gastric neoplasm: A prospective single-center analysis based on tumor characteristics stratified by biopsy number and site

Although there are general guidelines on endoscopic biopsy for diagnosing gastric neoplasms, they are predominantly based on outdated literature obtained with fiberscopes without analyses specific to tumor characteristics.This study aims to comprehensively characterize the contemporary endoscopic biopsy by determining the diagnostic yield across different lesion morphologies and histological stages, especially exploring how the number and site of biopsy may influence the overall yield.Biopsy samples from suspected gastric neoplasms were collected prospectively from May 2011 to August 2014 in a tertiary care medical center. A standardized methodology was used to obtain a total of 6 specimens from 2 defined sites per lesion. Rate of positive diagnosis based on the biopsy number and site was assessed for specific gastric lesion morphologies and histological stages.A total of 1080 biopsies from 180 pathologically diagnosed neoplastic lesions in 176 patients were obtained during the study. For depressed/ulcerative and polypoid lesions, the yield was already >99% by the fourth biopsy without further gain from additional biopsies. Lower overall yield was observed for infiltrative lesions (57.1% from 4 biopsies). The site of biopsy did not influence the diagnostic yield except for with infiltrative lesions in which biopsies from thickened mucosal folds were of higher yield than erosive regions.Obtaining 4 specimens may be sufficient for accurate diagnosis of a depressed/ulcerative or polypoid gastric lesion regardless of its histological stage. For infiltrative lesions, at least 5 to 6 biopsies per lesion with more representative sampling from thickened mucosal folds may be preferable.

Pycnogenol induces differentiation and apoptosis in human promyeloid leukemia HL-60 cells

Pycnogenol, rich of many phytochemicals of medical value, is a commercialized nutrient supplement extracted from the bark of European coastal pine. In this study, we investigated the anti-tumor effects of Pycnogenol on HL-60, U937 and K562 human leukemia cell lines. We found that Pycnogenol inhibited cell proliferation dose- and time-dependently, and the IC(50)s of Pycnogenol on HL-60, U937 and K562 cells were 150, 40 and 100 microg/ml, respectively. When HL-60 cells were incubated with low concentrations of Pycnogenol (50, 100 and 125 microg/ml) for 24 h, a prominent G0/G1 arrest was observed, followed by gradual accumulation of sub-G0/G1 nuclei. At 48 h of treatment, 50-70% of HL-60 cells differentiated, as evidenced by morphological changes, NBT reduction, induction of NSE activity, and increases of cell surface expression of CD11b. However, results from Annexin V/PI staining, DAPI staining and DNA fragmentation assay indicated that Pycnogenol induced HL-60, U937 and K562 cell apoptosis at their respective IC(50)s after 24 h of treatments. Pretreatment of z-DEVD-fmk, a caspase-3 specific inhibitor, not only decreased caspase-3 activity but also reduced the percentage of apoptotic cells induced by Pycnogenol. This indicated that caspase-3 activation was involved in Pycnogenol induced-apoptosis. In conclusion, Pycnogenol induced differentiation and apoptosis in leukemia cells. Our data suggest that Pycnogenol could serve as a potent cancer chemopreventive or chemotherapeutic agent for human leukemia.

Exercise-induced myocardial ischaemia complicated by paroxysmal complete atrioventricular block

This study describes a case of exercise-induced myocardial ischaemia accompanied by complete atrioventricular block (CAVB). A 59-year-old man with major depression, treated with regular imipramine and lithium for 20 years, experienced syncope episodes during exercise. Exercise, testing initially, identified ST depression in the inferior leads, and later found CAVB resulting in syncope and seizure. The patient recovered completely after resuscitation. Myocardial ischaemic markers were negative, but 35% stenosis was detected in the distal left main coronary artery by angiography. The combined use of verapamil, nitrate and aspirin was treated as the possible coronary spasm. Repeat treadmill caused negative ischaemic study or exercise-induced arrhythmia, 7 days later. The pathophysiology of the very rare exercise-induced paroxysmal CAVB has been reviewed.

Heart failure due to giant congenital aorto-right atrial fistula: report of a case

Coronary arterio-venous fistula (CAVF) is a rare coronary artery anomaly. We demonstrated the rare findings of a large congenital aorto-right atrial fistula with initial presentation of heart failure symptoms. Transthoracic echocardiography and transesophageal echocardiography made the accurate diagnosis. Further haemodynamic and angiographic study proved this large CAVF with extraordinary oxygen saturation step-up (26%) and large pulmonary to systemic shunt (Qp/Qs = 4.25). It was corrected by surgery because of evidence of heart failure and the possible risk of endocarditis and coronary steal effect.

Right pneumothorax resulting from an endocardial screw-in atrial lead

Right pneumothorax complicated by an endocardial atrial lead has never been reported. Herein, we report on a small-build 79-year-old Taiwanese woman who suffered from complete AV block and underwent dual-chamber permanent pacemaker implantation. An active fixation screw-in atrial lead was chosen. The procedure was complicated by right pneumothorax associated with atrial perforation. Since simple measurements of the implantation parameters could not be used to predict the occurrence of perforation, great caution should be taken in to avoid overscrewing the atrial lead, and in scrutinizing the penetration depth of the helix of the lead under fluoroscopy.

Localizing intrapulmonary shunt in hepatopulmonary syndrome by transesophageal echocardiography

Transesophageal echocardiography combining with peripheral injection of agitated saline solution is a useful diagnostic tool to detect the intrapulmonary shunt. We performed transesophageal contrast echocardiography in a case of hepatopulmonary syndrome with normal pulmonary angiography to define the intrapulmonary right-to-left shunt bilaterally.