Caplacizumab Use in a TTP Case Unresponsive to Conventional Therapy

Introduction Thrombotic Thrombocytopenic Purpura (TTP) is a rare but life-threatening disorder caused by severely reduced activity of ADAMTS13, causing platelet adhesion and formation of small-vessel platelet-rich thrombi, thrombocytopenia, and microangiopathic haemolytic anaemia. Diagnosis A 48-year-old female presented with acute generalized petechial rash, bruises, and fatigue. Bloods revealed thrombocytopenia, anaemia, 10% schistocytes. Her plasmic score was seven, and ADAMT13 was <5. Treatment Patient initially responded to plasma exchange and steroids, but thrombocytopenia recurred on day six of treatment, needing the addition of further immunosuppressive drugs and Caplacizumab. Conclusion TTP cases unresponsive to conventional regimens can represent a challenging situation; however, poor outcomes could potentially be avoided with a novel therapy like Caplacizumab. In our patient, this medication was well tolerated, and platelet count normalized after two days of its introduction.

Abstract 1705: Spatial interrogation of tertiary lymphoid structures (TLS) in colorectal carcinoma (CRC) tumor microenvironment (TME) using the MultiOmyx࣪ assay

Immune checkpoint blockade (ICB) therapy has revolutionized the landscape of cancer therapy in multiple tumor types since Ipilimumab, the first ICB agent, was approved for the treatment of metastatic melanoma is 2011. Current predictive biomarkers for therapy response include PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability (MSI) status. However, responses to ICB vary widely and these predictive markers have demonstrated imperfect predictive power to ICB therapy. For instance, half of microsatellite instability-high (MSI-H) colorectal carcinoma (CRC) patients do not respond to ICB immunotherapy. There is still a crucial need to identify and develop biomarkers predictive of outcome to ICB therapy. Tertiary lymphoid structures (TLS) have been observed in a variety of solid tumors in humans, and their presence is a favorable prognostic indicator for survival in a variety of solid cancers including CRC. Further, it was recently shown that the presence of mature TLS was associated with improved response rate to ICB and overall survival in patients with advanced tumors in a large retrospective study. In this study, we used a 17-plex MultiOmyx panel to detect TLS, explore TLS maturation stage and characterize the tumor microenvironment (TME) in 40 CRC patients with known MSI status. The 17-plex includes CD3, CD4, CD8, CD45RO, FOXP3, CD20, CD56, CD68, CTLA-4, PD1, PD-L1, CXCL13, PNAd, CD21, CD23, DC-LAMP and PanCK. Using this panel, we successfully detected different stages of TLS in these CRC samples. Using proprietary deep-learning-based image analysis algorithm (NeoLYTX), we quantified TLS’s in the CRC samples and classified them by maturation stage based on biomarker expression and spatial organization of immune cells. While there was no difference in the number of early TLS (E-TLS; characterized by CD3, CD20 and pNAd) between MSI-H and microsatellite-stable (MSS) CRC samples, more primary follicle-like TLS (P-TLS; defined by CD3, CD20 and CD21) and secondary follicle-like TLS (S-TLS; defined by CD3, CD20 and CD23) were observed in the MSI-H group than the MSS group. In particular, the abundance of mature S-TLS was significantly higher in MSI-H CRC samples. This 17-plex MultiOmyx assay provides a powerful tool to characterize the cellular composition and spatial organization of the tumor microenvironment. The panel enables quantification of TLS, PD-L1 expression and abundance of tumor infiltrating lymphocytes from one single FFPE slide. The rich datasets generated by the MultiOmyx assay can provide greater understanding of the immune contexture within the TME and deeper insights into the correlations between biomarkers. These findings may have broad application and help identify biomarker signatures with improved predictive performance to immune checkpoint inhibition efficacy in solid tumors.

Citation Format: Harry Nunns, Erinn A. Parnell, Michael Lazare, Judy Kuo, Eric Leones, Flora Sahafi, Josette William, Qingyan Au. Spatial interrogation of tertiary lymphoid structures (TLS) in colorectal carcinoma (CRC) tumor microenvironment (TME) using the MultiOmyx࣪ assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1705.

Abstract 2778: Validation of a next generation sequencing clinical assay for detection of immunoglobulin heavy chain clonality and somatic hypermutation in chronic lymphocytic leukemia

Next-generation sequencing (NGS) provides a powerful high-throughput approach to identify and track B-cell immunoglobulin (IG) heavy chain clonality and to assess somatic hypermutation status in a massively parallel manner. The NGS-based clonality/SHM testing demonstrated superior performance over the conventional capillary electrophoresis (CE) methods in characterization of B-cell neoplasms. However, its broad utilization in clinical diagnostics requires extensive validation of assays as well as standardization of data interpretation. We present here an NGS assay designed and validated specifically for IG clonality/SHM characterization of B-cell malignancies. The assay was designed to simultaneously target the Leader, FR1, FR2, and FR3 regions of the IGH gene to identify clonal IGH VH-JH rearrangement as well as the IGK gene to identify clonal IGK VK-JK, VK-Kde, and INTR-Kde rearrangement. The validation was performed to assess assay accuracy, specificity, sensitivity, repeatability, and reproducibility, with both pre-characterized reference controls and prospectively collected clinic peripheral blood and bone marrow aspirate specimen included. Triplicates were included and testing was performed at different times and by different operators to assess the assay precision. Over 60 clinic peripheral blood and bone marrow aspirate specimens were collected, including patients with B-cell malignancies such as CLL, B-ALL, and DLBCL as well as heathy donors, processed within 7 days for DNA extraction, and assessed by the NGS assay for IGH clonality and SHM assessment. Assay sensitivity as low as 2.5% for baseline clonality and as low as 0.001% for tracking MRD were observed. Near-perfect assay specificity and precision were observed at these sensitivity levels. The validated NGS assay was further qualified by ERIC (the European Research Initiative on CLL) with a certificate granted to standardize the data interpretation of this assay for testing in chronic lymphocytic leukemia. In conclusion, a NGS IG clonality/SHM assay was analytically and clinically validated under medical oversight, with a demonstrated rigor of the test by its high sensitivity/specificity and robust reproducibility. The clinical diagnostic testing results with this assay is interpreted in accordance with ERIC standards for reliable clinical reporting.

Citation Format: Xin-Xing Tan, Tricia Peters, Meredith Berry, Kristyn Jeter, Brigitte Lovell, Victor Venegas, Yanglong Mou, Brad Thomas, Vincent Funari, Josette William. Validation of a next generation sequencing clinical assay for detection of immunoglobulin heavy chain clonality and somatic hypermutation in chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2778.

51 A novel cross-site analysis of Vectra® Polaris™ multiplex fluorescence PD-1/PD-L1 immunohistochemistry on colorectal cancer with high and low microsatellite instability

Background

Colorectal cancer (CRC) is the third most diagnosed cancer in the United States with a projected 52,980 deaths in 2021.1 Microsatellite instability-high (MSI-H) CRCs with deficiencies in mismatch repair (MMR) are significantly associated with positive response to immunotherapy and improved outcomes when treated with immune checkpoint inhibitors. Programmed cell death ligand-1 (PD-L1) is an effective biomarker of MSI-H status to identify CRC patients who will respond to treatment, however, reproducible quantification of programmed cell death receptor-1 (PD-1)/PD-L1 in the tumor microenvironment (TME) across laboratory sites has been under-reported.2–3 In this study, our group directly addressed this issue by interrogating PD-1/PD-L1 cross-site at Akoya Biosciences and NeoGenomics Laboratories by employing the MOTiF™ PD-1/PD-L1 Panel kit along with the Vectra Polaris imaging system.

Methods

Serial sections from 40 CRC samples with known MSI status were stained at Akoya and NeoGenomics Laboratories using a modified MOTiF PD-1/PD-L1 Lung Panel Kit on the Leica BOND RX. Sections were scanned using the Vectra Polaris imaging system at both sites. Inter-site staining reproducibility was assessed using image analysis algorithms developed with inForm tissue analysis software. Cell counts and densities were calculated using the R-script package PhenoptrReports and correlations were plotted per marker.

Results

The average signal intensity for all markers/Opal fluorophores was within the recommended ranges of 10–30 normalized counts, with the exception of Polaris 780, which has an advised range of 1–10. This indicates the protocol stained successfully and reproducibly across all serial sections at both sites. Inter-site concordance analysis of cell densities for each marker yielded an average R2 value of ≥0.70. H-Score of PD-L1 quantified at the cell membrane trended with MSI status (stable/high).

Conclusions

This study demonstrated that the MOTiF PD-1/PD-L1 Panel kit imaged in conjunction with the Vectra Polaris is not only a reliable assay that can be run across different sites, based on the concordant cross-site data, but that re-optimization of the kit allows for the assay panel to be successfully adapted to other cancers, such as CRC, which can then capture biological differences across a multitude of samples.

References

American Cancer Society https://www.cancer.org/cancer/colon-rectal-cancer/about/key-statistics.html

Yi M, Jiao D, Xu H, Liu Q, Zhao W, Han X, et al. Biomarkers for predicting efficacy of PD-1/PD-L1 inhibitors. Mol Cancer 2018;17(1):129

Lemery S, Keegan P, Pazdur R. First FDA approval agnostic of cancer site - when a biomarker defines the indication. N Engl J Med 2017;377(15):1409–12.

Long-term implications of pacemaker insertion in younger adults: a single centre experience

Background

The long-term implications of pacemaker insertion in younger adults are poorly described in the literature.

Methods

We performed a retrospective analysis of consecutive younger adult patients (18–50 years) undergoing pacemaker implantation at a quaternary hospital between 1986–2020. Defibrillators and cardiac resynchronisation therapy devices were excluded. All clinical records, pacemaker checks and echocardiograms were reviewed.

Results

81 patients (39.5±9.6 years, 53% male) underwent pacemaker implantation. Indications were complete heart block (41%), sinus node dysfunction (33%), high grade AV block (11%) and tachycardia-bradycardia syndrome (7%). During a median 7.6 (IQR=0.6–14.8) years follow-up, 9 patients (11%) developed 13 late device-related complications (generator or lead malfunction requiring reoperation (n=11), device infection (n=1) and pocket revision (n=1)). Five of these patients were <40 years old at time of pacemaker insertion. At long-term follow-up, a further 9 patients (11%) experienced significant symptoms from inadequate lead performance managed with device reprogramming. Sustained ventricular tachycardia was detected in 2 patients (2%). Deterioration in ventricular function (LVEF decline >10%) was observed in 14 patients (17%) and 7 of these patients required subsequent biventricular upgrade. Furthermore, 4 patients (5%) developed new tricuspid regurgitation (≥ moderate-severe). Of 69 patients with available long-term pacing data, minimal pacemaker utilisation (pacing <5% at all checks) was observed in 13 (19%) patients.

Conclusions

Pacemaker insertion in younger adults has significant long-term implications. Clinicians should carefully consider pacemaker insertion in this cohort given risk of device-related complications, potential for device under-utilisation and issues related to lead longevity. In addition, patients require close follow-up for development of structural abnormalities and arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

Abstract 434: Characterizing viral mRNA and immuno-protein expression in head and neck squamous cell carcinoma using a novel automated RNAscope™/Polaris™ integrated assay

Background: Chronic viral infection can generate inflammatory microenvironments leading to neoplastic growth and cancer development. Cancer patients with chronic viral infection have been shown to exhibit worse outcomes compared to non-infected individuals. One such cohort, head and neck squamous cell carcinoma (HNSCC) patients infected with chronic human cytomegalovirus (CMV), have increased risk of death when receiving radiotherapy or radiochemotherapy. This is clinically significant as HNSCC already carries a high mortality rate and low response to surgery and chemotherapeutic treatment. The ability to detect and localize viral infection and immune response in the same patient tissues has been historically under-developed and may assist in stratifying patients for therapeutic intervention.

Methods: Immune infiltrate to tumor in CMV infected and non-infected samples was assessed in HNSCC patient tissue using RNAscope in-situ hybridization (ISH) probe to detect CMV mRNA and Vectra® Polaris™ automated multiplex protein detection of CD8, PD-L1, CD68 and panCK with OPAL dyes.

Results: We developed a novel automated RNAscope™/Vectra® Polaris™ integrated multiplex immunofluorescence (IF) assay with OPAL detection and quantification of signal using Indica HALO® algorithms. The results include quantitative and reproducible RNAscope fluorescent ISH counting, cell-by-cell expression profiles, multiplex protein quantification and whole-slide image analysis.

Conclusion: NeoGenomics Laboratories RNAscope™/Polaris™ integrated assay detects and quantifies CMV viral infection and protein expression of PD-L1 positive and negative cytotoxic T cells and macrophages within and adjacent to HNSCC tumor regions.

Citation Format: Sara Pollan, Arezoo Hanifi, Mate Nagy, Nicholas Stavrou, Erinn Parnell, Maricel Gozo, Nickolas Attanasio, Josette William, Qingyan Au. Characterizing viral mRNA and immuno-protein expression in head and neck squamous cell carcinoma using a novel automated RNAscope™/Polaris™ integrated assay [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 434.

Hydroethanolic leaf extract of Parthenium hysterophorus attenuates blood glucose in alloxan induced diabetic mice

The Parthenium hysterophorus (P. hysterophorus) is used to treat diabetes mellitus in local medicinal system of Pakistan but very limited scientifically proved information is available in this context. The objective of this work was to evaluate the antioxidant and antidiabetic activity of P. hysterophorus leaf extract. The extraction was made with freeze drying assisted ultrasonication using 40%, 60% and 80% ethanol as solvent. The total phenolic and flavonoid contents were calculated. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and α-glucosidase inhibitory assay was also performed. The in vivo hypoglycemic potential of leaf extract was determined in alloxan monohydrate induced diabetic mice. The 60% ethanolic extract exhibited comparatively higher phenolic and flavonoid contents with values of 105.44±2.55 mg GAE/g D.E and 41.50±2.25 mg RE/g D.E, respectively. The 60% extract also possessed lowest IC50 value of 87.55 μg/mL and 98.22 μg/mL for DPPH radical scavenging and α-glucosidase inhibition, respectively. The same extract substantially reduced the blood glucose level in alloxan induced diabetic mice and results were quite comparable with standard drug metformin. The extract dose of 450 mg/kg reduced the blood glucose level of diabetic mice from 268.05 mg/dL 137.88 mg/dL at the end of 28 days treatment. The findings confirmed the ethnopharmacological use of P. hysterophorus to treat and manage diabetes mellitus type 2. The experimental outcomes may be employed as pharmacological leads to treat diabetes mellitus and to develop functional foods with hypoglycemic attributes.

Abstract 2143: Profiling exhausted T cells using Vectra® Polaris™multiplex immunofluorescence assay in HNSCC

Background: Head and neck squamous cell carcinoma (HNSCC) is a cancer with the ability to modulate the immune system to evade detection. It is the sixth most frequently diagnosed cancer with 550,000 new cases and 300,000 lives lost worldwide per year. New treatments for HNSCC are urgently needed as patients continue to experience a high mortality rate and low response to surgery and chemotherapeutic treatments. Part of the reason why HNSCC is difficult to treat is it upregulates the expression of immune-checkpoint signaling molecule TIGIT (T cell immunoreceptor with Ig and ITIM domains) to inhibit T cell activation in vivo. Emerging evidence shows TIGIT overexpression in the CD8+ and CD4+ T cells that infiltrate the tumor cells of HNSCC patients. TIGIT expression is also associated with up-regulation of immune-checkpoint ligands PD-1 (programmed cell death protein 1) and LAG-3 (lymphocyte-activation gene 3 aka CD223), markers of T-cell exhaustion. Altogether, activation of the TIGIT/PD-1/LAG-3 axis correlates with an immunosuppressive microenvironment as well as cancer development and progression. Although there is ample evidence that the upregulation of TIGIT decreases the immune response in HNSCC, only limited studies have been published that address the location, expression and co-expression of TIGIT, LAG-3 and PD-1 in the HNSCC microenvironment.

Methods: In this study, we sought to establish a robust report of immune cells in the tissue of patients with HNSCC. Using Vectra Polaris multiplex immunofluorescence (IF) assays, we studied T-cell exhaustion and T-cell expression in HNSCC patient tissue using a total of 9 markers essential in cancer immunology. Sequential tissue sections were stained in two panels of 6, an exhausted T cell panel comprised of TIGIT, PD-1, LAG-3, panCK, CD4 and CD8 and a T cell panel including CD3, FOXP3, CD45RO, panCK, CD4 and CD8.

Results: Multiplexing IF staining revealed a HNSCC histologic landscape characteristic of immune suppression in this study. The data demonstrated abundant T cells with TIGIT overexpression in the tissue microenvironment of HNSCC samples. Using Indica Halo algorithms, we quantified exhausted T cells (TIGIT+PD1+LAG3+CD4+CD3+, TIGIT+PD1+LAG3+CD8+CD3+), T helper cells (CD3+CD4+), T cytotoxic cells (CD3+CD8+), T regulatory cells (CD3+CD4+FoxP3), memory T-cells (CD3+CD4+CD45RO) and anergic T-cells (PD1+CD8+) within the tumor and the stromal regions.

Conclusion: Currently AB154, a fully humanized immunoglobulin G1 monoclonal antibody targeting human TIGIT is in phase I clinical trials in HNSCC patients and BGB-A1217, an anti-TIGIT monoclonal antibody in combination with anti-PD-1 monoclonal antibody Tislelizumab is in a Phase 1/1b clinical trial in patients with advanced solid tumors. The Vectra Polaris imaging reported in this study identifies T cell composition in the tumor microenvironment of patients facing high mortality.

Citation Format: Sara Pollan, Arezoo Hanifi, Mate Nagy, Nicholas Stavrou, Erinn Parnell, Maricel Gozo, Nickolas Attanasio, Josette William, Qingyan Au. Profiling exhausted T cells using Vectra® Polaris™multiplex immunofluorescence assay in HNSCC [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 2143.

Abstract 1175: A pro-tumorigenic mechanism of M2 tumor-associated macrophages in triple-negative breast cancer

Introduction:

Triple-negative breast cancers (TNBCs) are defined as tumors that are negative for both estrogen, progesterone and HER-2 receptors. It is a heterogeneous subtype of breast cancer with a high propensity for systemic metastases and poor survival with only chemotherapy available for treatment. Compared to other hormone-positive breast cancer subtypes, TNBC features a unique tumor microenvironment (TME) characterized by a large number of tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) (1), and the increase of immune infiltrate with high levels of TILs predicts response to neoadjuvant chemotherapy as well as improved survival.

TAMs can be described as classically activated M1 types with pro-inflammatory antitumor functions, versus alternatively activated M2 types with immunosuppressive pro-tumor functions. It has been reported that the presence of M2 TAMs positively correlates with TNBC, hormone receptor negativity, as well as higher tumor proliferation (2-3). However, the mechanisms by which TAMs interact with TNBC cells and their phenotypes in TNBC versus estrogen receptor positive (ER+) patients is not well understood.

Experimental Procedures:

Using MultiOmyx, a proprietary, immunofluorescence (IF) multiplexing assay that enables visualization and characterization of up to 60 biomarkers on a single FFPE section (4), we have characterized TIL phenotypes, tumor proliferation and TAM activation in 15 FFPE tumors from TNBC and 5 tumors from ER+ patients.

Results:

Using a multiplex panel of 9 markers we found a 10-fold higher number of TILs and a 5-fold higher number of proliferating tumor cells in TNBC versus ER+ tumors. Furthermore, the proportion of T helper cells (CD3+CD4+) that were Tregs (CD3+CD4+FoxP3+) was increased from 26% to 43% in TNBC tumors. Interestingly, when analyzing TAMs we found that while ER+ tumors had a significantly higher proportion of M1 TAMs (CD68+HLA-DR+) than M2 TAMs (CD68+CD163+), this expression pattern was reversed in TNBC. When analyzing a possible correlation between the activation state of TAMs and the proliferation of tumor cells, we found a positive significant correlation between the presence of M2 TAMs and proliferating tumor cells (Pearson's correlation p<0.05), only in TNBC and not in ER+ tumors. Conversely, the presence of M1 tumors showed a weak negative correlation to tumor cell proliferation, in both ER+ and TNBC tumors.

Conclusion:

These data are suggestive of a possible pathway in which an increase in alternatively activated immunosuppressive M2 TAMs in hormone receptor negative breast cancer tumors, are responsible for providing a suitable environment for tumor proliferation.

References:

1. Yu T & Di G, Chin J Cancer Res 2017;29(3):237.

2. Medrek C et al., BMC Cancer 2012;23(12):306.

3. Klingen TA et al., Hum Pathol 2017;(69):72.

4. Gerdes MJ et al. PNAS 2013;(110):11982.

Citation Format: Anna Juncker-Jensen, Nicholas Stavrou, Raghav Padmanabhan, Erinn Parnell, Judy Kuo, Eric Leones, Flora Sahafi, Josette William. A pro-tumorigenic mechanism of M2 tumor-associated macrophages in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1175.

Abstract 497: Characterization of TIGIT expression using MultiOmyxTM hyperplexed immunofluorescence assay in solid tumors

TIGIT (T cell immunoreceptor with Ig and ITIM domains) is a recently identified immune-receptor that is expressed on T cells, natural killer (NK) cells and NKT cells. TIGIT has emerged as an important coinhibitory receptor. TIGIT expression on CD8+ tumor infiltrating lymphocytes (TILs) has been shown to be upregulated in solid cancers such as melanoma, colon cancer, and NSCLC and have been associated with a dysfunctional phenotype in TILs. TIGIT can also be activated on a subset of Regulatory T cells (Tregs) and may be critical in driving CD8+ T cell dysfunction. A second mechanism in which TIGIT inhibits immunosurveillance is through both competition and direct inhibition of CD226, impairing its ability to activate immunosurveillance. TIGIT has also been reported to inhibit T cell responses indirectly by triggering CD155 expression in dendritic cells (DCs), thereby preventing DC maturation. These findings render the TIGIT pathway as an attractive candidate for cancer immunotherapy In this study, we seek to use MultiOmyx hyperplexed immunofluorescence (IF) assay to exploit this new pathway and characterize the TIGIT expression in a total of 20 melanoma and NSCLC samples. The cancer FFPE slides will be stained with a 13-marker panel including TIGIT, CD226, CD155, CD3, CD4, CD8, FOXP3, CD56, CD45, CD11b, CD11c, PD1, LAG3, TIM3 and PanCK. This panel will enable the detection of TIGIT, CD226 and CD115 expression in the Melanoma and NSCLC samples. The TIGIT expression will be further characterized on different TILs including CD4+ helper T cells, CD8+ cytotoxic T cells, Tregs and NK cells. Using the MultiOmyx proprietary algorithm, we can quantify different subtypes of TIGIT expressing cells and measure the distance of different TIGIT expressing cells to the tumor. Increased expression of TIGIT and PD1 has been demonstrated in NSCLC and melanoma. Moreover, TIGIT+ Tregs have been reported to upregulate TIM-3 expression in mice tumor models. In this study, we will also evaluate the expression of TIGIT in conjunction with other coinhibitory receptors such as PD1, LAG3 and TIM3. The percentage of TILs that co-express TIGIT/PD1, TIGIT/LAG3 and TIGIT/TIM3 will be quantified and analyzed. Leveraging TIGIT in combination with other immune therapy may achieve more robust clinical outcomes. There are currently multiple phase I clinical trials using TIGIT monoclonal antibody (for instance, BMS-986207 by Bristol-Myers Squibb and MTIG7192A by Genetech) in combination with anti PD1/PDL1 antibodies in solid tumors. Our data can help provide more insight into how TIGIT modulate antitumor immunity in melanoma and NSCLC tumors. And the findings in this study can also be used to understand the synergistic effects between TIGIT and other coinhibitory receptors and help identify the additional opportunity for combination immunotherapy using checkpoint inhibitors.

Citation Format: Qingyan Au, Arezoo Hanifi, Erinn Parnell, Judy Kuo, Eric Leones, Flora Sahafi, Kathy Pham, RaghavKrishna Padmanabhan, Nicholas Hoe, Josette William. Characterization of TIGIT expression using MultiOmyxTM hyperplexed immunofluorescence assay in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 497.

Using a multiplexed immunofluorescence approach to compare immune cell populations in subtypes of non-small cell lung cancer

e20702

Background: Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancer cases, and is characterized by a poor response to chemotherapy and a low survival rate. While immunotherapy has recently emerged as a successful approach in the treatment of NSCLC patients only 20-25% of patients show a positive response to anti-PD/PDL1 therapy, stressing the urgent need for additional immunotherapy options. NSCLC is a very heterogeneous disease with the two most common types being adenocarcinoma (ADCA) and squamous cell carcinoma (SCC). While a study using flow cytometry to analyze NSCLC on protein level reported the immune cell composition to be fundamentally different in ADCA compared with SCC (Daraselia et al. Am J Cancer Res, 2012 2(1):93), to the best of our knowledge this study will be the first of its kind performing an extensive analysis of NSCLS immune cell composition in tissue. Methods: In order to perform this comprehensive immunoprofiling of the NSCLC subtypes ADCA and SCC we will be using MultiOmyx™, an immunofluorescence (IF) multiplexing assay with similar staining characteristics as standard IHC stains but with the significant advantage that up to 60 protein biomarkers can be interrogated from a single FFPE section. Proprietary cell segmentation algorithms generate unique IDs for every cell and deep learning based cell classification algorithms then identify positive cells for each biomarker. Results: Using a 16-marker panel consisting of CD3, CD4, CD8, FoxP3, CD20, CD68, CD163, CD15, PD1, PDL1, ICOS, OX40, LAG-3, TIM-3, and PanCK we will analyze the proportion of B cells, T cell subtypes, M1/M2-type tumor-associated macrophages, as well as the expression of PD1/PDL1, in addition to novel immunotherapy targets LAG3, TIM3, ICOS, and OX40 in 20 samples from patients with NSCLC (10 ADCA and 10 SCC). Finally, from the same FFPE blocks that we will use to profile the immune cell composition on protein level we will also be extracting DNA/RNA in order to perform T cell receptor (TCR) sequencing, which will provide additional information on the diversity of T cells present in these tumors. Conclusions: It is our hope that these data will help provide new insights into the biology of ADCA and SCC that can ultimately be used to explore novel immunotherapeutic interventions for lung cancer treatment.

Quantitative image profiling of the tumor microenvironment on double stained immunohistochemistry images using deep learning

e14619

Background: Spatial locations of immune cells in the tumor microenvironment (TME) correlate with clinical outcome in cancers. A worse patient outcome has been reported in oral squamous cancer for individuals with an increased number of regulatory T cells within 30µm of CD8+ cells [1]. The spatial relationship between CD8+ and PD-L1+ cells has become an area of interest for understanding PD-L1 inhibition. The combined assessment of CD8 and PD-L1 in NSCLC tumors was shown to outperform CD8 or PD-L1 alone as prognostic markers for predicting treatment with immune checkpoint inhibitors [2]. Methods: As reported in these cases, quantifying spatial relationships between two biomarkers is valuable in providing clinical insights. Spatial analytics of the TME requires accurate cell segmentation and classification. To that end, NeoGenomics has developed a deep learning pipeline to automatically segment and classify cells from whole slide double stained IHC images. Results: In this study, we performed IHC double staining and cell classification analysis on two sets of assays (CD8+ PD-L1+ and CD8+ FoxP3+) in NSCLC tumors by modifying our MultiOmyx analysis pipeline [3]. In addition to cell segmentation and classification image outputs, we also generate tables with cell morphological information, phenotype counts and densities, and biomarker intensities that can be used to define H-score-like measures. Advanced spatial analytics is performed to identify clustering patterns of various phenotypes. These analyses enable investigation of complex cell interactions in TMEs. Conclusions: NeoGenomics quantitative double stained IHC assay is compatible with any two biomarkers of interest even if they are expressed on the same cell as long as the sub-cellular localization of the markers is different (membrane CD8, nuclear FoxP3). The combination of double staining for CD8+ PD-L1+ or CD8+ FoxP3+ and quantifying spatial relationships between the two biomarkers is capable of providing the needed context to guide treatment decisions. References: Feng Z et al., JCI Insight. 2017 Jul 20:e93652 Steele KE et al., J Immunother Cancer 2018;6:20 Nagy ML et al., AACR Annual Meeting 2018; April 14-18, 2018; Chicago, IL

Development of a clinical trial immunohistochemistry (IHC) assay using a novel antibody to CD38

7561

Background: CD38 is a type II transmembrane glycoprotein expressed on normal lymphoid and myeloid cells and can be highly expressed in hematologic malignancies. An IHC prototype assay was developed to detect CD38 expression in formalin-fixed, paraffin-embedded (FFPE) tissue specimens from three relapsed or refractory non-Hodgkin’s lymphoma (NHL) subtypes: diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and mantle cell lymphoma (MCL) for selection of patients for treatment with daratumumab in a Phase 2 clinical trial (NCT02413489). Methods: This assay is based on EnVision FLEX IHC technology using CD38, clone DAK-CD38, primary antibody that has been developed and manufactured by Agilent Technologies. The assay staining protocol was developed for Dako PT Link and Autostainer Link 48. Specificity of DAK-CD38 staining was demonstrated by Western blot analysis of cancer cell lysates, as well as IHC on both normal and cancer tissue. Assay precision and robustness were evaluated using commercially procured FFPE DLBCL, FL and MCL specimens. Results: CD38 IHC DAK-CD38 detected a broad range of CD38 expression in DLBCL, FL, and MCL specimens. FFPE specimens derived from cancer cell lines exhibited a range of IHC staining intensity and confirmed the reported expression of CD38 in the scientific literature. All precision and robustness results met acceptance criteria for both IHC intensity and percent positive cells staining. Conclusions: Our studies demonstrate that the Dako CD38 IHC DAK-CD38 assay is sensitive, specific, precise, and robust for the detection of CD38 expression in DLBCL, FL and MCL. This assay may also have the potential to be used for the detection of CD38 in additional tumor types.

Development of a diagnostic PD-L1 immunohistochemical assay for nivolumab therapy in urothelial carcinoma

e14585

Background: PD-L1 IHC 28-8 pharmDx is a qualitative assay developed by Agilent Technologies for the Autostainer Link 48 platform and is based on EnVision FLEX visualization technology and monoclonal rabbit anti-PD-L1, clone 28-8 antibody. The assay has been co-developed with the immunotherapeutic agent nivolumab; initially as an aid in assessing PD-L1 expression in non-squamous non-small cell lung cancer (NSCLC) and melanoma patients. Here we describe the efforts to validate this assay for urothelial carcinoma (UC). Methods: IHC staining was performed on Autostainer Link 48 platform using an automated staining protocol stated per the assay’s instruction for use (IFU). Specimens were coverslipped and interpreted for % PD-L1 positive tumor cells. The assay was analytically validated on commercially acquired formalin-fixed, paraffin-embedded (FFPE) human UC invasive tumor specimens at ≥1% and ≥5% PD-L1 positive tumor cells expression levels. Results: A wide range of % PD-L1 positive tumor cells at all staining intensity levels have been detected. Assay in-house precision was validated for inter-operator, inter-instrument, inter-day, inter-run and intra-run as well as inter-observer and intra-observer agreement. Robustness studies evaluated the assay under multiple conditions for target retrieval pH, temperature and incubation time, slide type as well as tissue section thickness. Assay reproducibility was evaluated at three external sites by testing samples for intra-site/inter-day and inter-site agreement measures. Specimens were also evaluated by an observer at each site, with three reads for each observer to assess intra-observer and inter-observer agreement. All validation studies demonstrated agreement estimates above 85% with values for lower bound 95% confidence intervals calculated above 84%. Conclusions: Results of all conducted studies show high robustness and reproducibility of the assay on UC.

Assay performance of the PD-L1 IHC 28-8 pharmDx assay in squamous cell carcinoma of the head and neck (SCCHN)

e14588

Background: The PD-L1 IHC 28-8 pharmDx assay has been developed for use in detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) non-squamous NSCLC and melanoma tissues for associated treatment effect with nivolumab. Validation of the assay for measuring PD-L1 expression level in human squamous cell carcinoma of the head and neck (SCCHN) FFPE sections has been conducted and results are described. Methods: Visualization of the PD-L1 IHC 28-8 pharmDx assay is based on the EnVision FLEX IHC technology. As described in the Instructions For Use, antigen retrieval was performed using the Dako PT Link, and the automated staining was conducted with Autostainer Link 48. The assay performance was validated on commercially procured FFPE SCCHN specimens. Results: Assessment of assay sensitivity to PD-L1 expression was measured on 236 unique specimens originating from squamous cell carcinoma of the tongue, tonsil, nasopharynx, oropharynx, hypopharynx, and larynx. The study demonstrated PD-L1 positive staining across a range of 0-95% positive tumor cells and 0 to 3+ staining intensity. Among these tested specimens, 44% of specimens had PD-L1 expression levels ≥1%. Assay robustness was validated by assessing critical parameters such as target retrieval solution pH, target retrieval solution temperature, target retrieval time, and cut section thickness. Assay reproducibility was evaluated in a study at three external sites. Reproducibility of intra-site, inter-day, and inter-site agreement was assessed in addition to inter- and intra-observer agreement. Assay robustness and reproducibility demonstrated agreement estimates above 85% with values for lower bound 95% confidence intervals calculated above 85%. Conclusions: These studies demonstrate that the PD-L1 IHC 28-8 pharmDx assay is reproducible and robust when used for automated detection of PD-L1 protein in FFPE human SCCHN specimens using Autostainer Link 48.

Abstract P5-15-12: Real-life activity of oral vinorelbine in metastatic breast cancer patients in the Unicancer ESME database

Background: In 2014, UNICANCER, composed of 18 French Comprehensive Cancer Centers, launched the Epidemiological Strategy and Medical Economics (ESME) program to investigate real-world data in oncology. Real-world data give the opportunity to assess the activity of specific products outside the framework of clinical trials. Oral vinorelbine (OV) is one of the therapeutic options available for metastatic breast cancer (mBC). Few data are available regarding its real clinical efficiency in current practice. We aimed at evaluating such activity within the ESME population.

Methods: The ESME-mBC database was built from information systems, treatment databases and patients' electronic files, with homogenous on-site collected information and high-level quality-control (Delaloge et al, Ann. Oncol 2016 (in press)). All patients having started a systemic treatment for mBC in a cancer center participating in the ESME program between 01-Jan-2008 and 31-Dec-2013 have been selected into the database.

For the purpose of the current analyses, data cut-off was July, 2015 and all patients who received OV at any time during the course of their disease were selected and analyzed. Primary end point was progression-free survival (PFS) from initiation of OV. Secondary end points were descriptive and prognostic analyses, and overall survival (OS).

Results: Among 13.853 patients recorded in the ESME-mBC database, 1402 received OV as a monotherapy or in combination (809 and 593 patients / 57.7% and 42.3% respectively). Most frequent combinations were with capecitabine (368 patients) and anti-HER2 therapy (165 patients). De-novo mBC was observed in 282 patients (20.1%) and 569 patients (40.6%) had only non-visceral metastases. At metastatic diagnosis, 221 patients (16.9%) had HER2-positive and 298 patients (22.9%) triple-negative tumors respectively. At OV initiation, median age was 59.0 [IC95%: 50-67] years. Endocrine therapy was given prior OV in 769 patients (54.9%). For PFS analysis, 1345 patients were evaluable. The following table summarizes PFS results according to the treatment patterns and the OV-line.

PFS results according to the treatment patterns and the OV-line  OV-line  1st line2nd line3rd line4th line and moreOverall populationN320414313270Overall populationPFS (months, [IC95%])4.7 [4.2-5.5]3.3 [3.0-3.5]2.9 [2.6-3.2]2.3 [2.1-2.4]OV monotherapyN118223207202OV monotherapyPFS (months, [IC95%])4.3 [3.1-5.3]3.2 [2.9-3.5]2.8 [2.5-3.2]2.2 [2.0-2.4]OV in combination with capecitabineN1531294925OV in combination with capecitabinePFS (months, [IC95%])5.1 [3.9-6.1]3.5 [2.8-4.6]3.0 [2.4-4.7]2.0 [1.4-5.2]OV in combination with anti-HER2N41503826OV in combination with anti-HER2PFS (months, [IC95%])6.0 [4.1-7.9]3.1 [2.4-3.8]3.3 [2.4-6.0]2.7 [1.9-3.7]

Following diagnosis of mBC, median OS was 38.2 months [IC95%: 36.1-40.0] in the cohort of patients who received OV at any time.

Conclusions:This study allows large scale assessment of real life benefit of OV over subsequent lines and shows that OV yields clinical benefit even in heavily pre-treated mBC patients.

Citation Format: Pierre H, Mahasti S, Damien P, Nicolas M, Chritelle L, Florence D, Mony U, Lionel U, William J, Paule A, Audrey M, Claudia L, Mario C, Marie-Paule S, Marie-Ange M-R, Marianne L, Jean-Christophe E, Thierry P, Jean-Marc F, Bruno C, Anthony G, Christian C, Gaëtane S, David P. Real-life activity of oral vinorelbine in metastatic breast cancer patients in the Unicancer ESME database [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-15-12.

Lymphoproliferative neoplasms of the lung: a review

CONTEXT

Diagnosis and classification of lymphomas are based on the morphologic, immunologic, and genetic features that the lesional cells share with their normal B and T lymphocyte counterparts. Primary pulmonary lymphomas account for 0.3% of primary lung neoplasms and less than 0.5% of all lymphomas.

OBJECTIVE

To describe and summarize the clinical and histopathologic features of the primary pulmonary lymphoma and secondary involvement of the lung by lymphoma.

DATA SOURCES

Peer-reviewed published literature and personal experience.

CONCLUSIONS

Diagnosis of clonal lymphoid proliferations in the lung has evolved owing to the greater utility of molecular and flow cytometric analysis of tissue. Further studies are needed to best define the clinical and prognostic features, as well as search for targeted therapy for these patients with rare neoplasms.

Endometriosis and ovarian cancer: a review of clinical, pathologic, and molecular aspects

Endometriosis is a chronic disease that affects millions of reproductive-age women. Despite the destructive and invasive nature of endometrioses, most cases are perpetually benign or eventually regress; however, atypical endometriosis is a precursor lesion and can lead to certain types of ovarian cancer. Endometriosis induced inflammation and auto- and paracrine production of sex steroid hormones contribute to ovarian tumorigenesis. These changes provide microenvironment necessary to accumulate enough genetic alterations for endometriosis associated malignant transformation. It takes years for endometriosis to undergo the pathophysiological progression that begins with atypical epithelial proliferation (atypical endometriosis and metaplasia), and then is followed by the formation of well-defined borderline tumors, and finally culminates in fully malignant ovarian cancer. This study is a review of the natural history of endometriosis and the role of microenvironments that favor the accumulation of genetic alterations and endometriosis-associated ovarian cancer progression.

Diagnosis of phosphaturic mesenchymal tumor (mixed connective tissue type) by cytopathology

Oncogenic osteomalacia (OO) is a rare paraneoplastic condition in which a bone or soft tissue tumor induces biochemical and clinical signs and symptoms of osteomalacia (or rickets) most often by the production of the phosphaturic protein, fibroblast growth factor-23. Phosphaturic mesenchymal tumor, mixed connective tissue type (PMTMCT) is a rare, histologically distinct tumor that represents the most common cause of OO. As the clinical diagnosis of OO is typically suspected on the basis of clinical and biochemical features and the presence of a bone or soft tissue tumor, cytologic examination might potentially provide the necessary pathologic confirmation of OO. In this case of a 46-year-old female with clinical stigmata of OO and a right distal humeral mass, we report that the fine-needle aspiration findings of short, cytologically bland spindled cells embedded in a fine, fibrillary stromal-rich matrix and the presence of osteoclast-type giant cells associated with the stromal matrix provide strong pathological evidence for PMTMCT and assist in pathologically confirming the clinical impression of OO, thus alleviating the need for a more invasive diagnostic surgical procedure.

Localization of ACE2 in the renal vasculature: amplification by angiotensin II type 1 receptor blockade using telmisartan

Angiotensin-converting enzyme (ACE)2 is a carboxypeptidase that degrades angiotensin II and other peptides. In the kidney, ACE2 localization within the glomerulus and tubules is cell specific. This study was aimed to investigate the localization of ACE2 within the renal vasculature. We also studied the effect of the administration of a specific angiotensin II type 1 receptor blocker, telmisartan, on ACE2 expression in the renal vasculature. ACE2 and ACE were localized in renal arterioles using confocal microscopy and specific cell markers. Quantitative measurements of ACE2 and ACE mRNA were estimated in kidney arterioles isolated by laser capture microdissection using real-time PCR. In kidney arterioles, ACE was localized in the endothelial layer, whereas ACE2 was localized in the tunica media. In mice treated with telmisartan (2 mg.kg(-1).day(-1)) for 2 wk, ACE2 expression was increased by immunostaining, whereas ACE expression was decreased. This was reflected in a decrease in the ACE/ACE2 ratio compared with vehicle-treated controls (0.53 +/- 0.14 vs. 7.59 +/- 2.72, P = 0.027, respectively). In kidney arterioles isolated by laser capture microdissection, the ACE/ACE2 mRNA ratio was also decreased compared with control mice (1.21 +/- 0.31 vs. 4.63 +/- 0.86, P = 0.044, respectively). In conclusion, in kidney arterioles ACE2 is preferentially localized in the tunica media, and its expression is increased after administration of the angiotensin II type 1 receptor blocker, telmisartan. Amplification of ACE2 in the renal vasculature may contribute to the therapeutic action of telmisartan by increasing angiotensin II degradation.

Glomerular localization and expression of Angiotensin-converting enzyme 2 and Angiotensin-converting enzyme: implications for albuminuria in diabetes

Angiotensin-converting enzyme 2 (ACE2) expression has been shown to be altered in renal tubules from diabetic mice. This study examined the localization of ACE and ACE2 within the glomerulus of kidneys from control (db/m) and diabetic (db/db) mice and the effect of chronic pharmacologic ACE2 inhibition. ACE2 co-localized with glomerular epithelial cell (podocyte) markers, and its localization within the podocyte was confirmed by immunogold labeling. ACE, by contrast, was seen only in glomerular endothelial cells. By immunohistochemistry, in glomeruli from db/db mice, strong ACE staining was found more frequently than in control mice (db/db 64.6 +/- 6.3 versus db/m 17.8 +/- 3.4%; P < 0.005). By contrast, strong ACE2 staining in glomeruli from diabetic mice was less frequently seen than in controls (db/db 4.3 +/- 2.4 versus db/m 30.6 +/- 13.6%; P < 0.05). For investigation of the significance of reduced glomerular ACE2 expression, db/db mice were treated for 16 wk with a specific ACE2 inhibitor (MLN-4760) alone or combined with telmisartan, a specific angiotensin II type 1 receptor blocker. At the end of the study, glomerular staining for fibronectin, an extracellular matrix protein, was increased in both db/db and db/m mice that were treated with MLN-4760. Urinary albumin excretion (UAE) increased significantly in MLN-4760-treated as compared with vehicle-treated db/db mice (743 +/- 200 versus 247 +/- 53.9 microg albumin/mg creatinine, respectively; P < 0.05), and the concomitant administration of telmisartan completely prevented the increase in UAE associated with the ACE2 inhibitor (161 +/- 56; P < 0.05). It is concluded that ACE2 is localized in the podocyte and that in db/db mice glomerular expression of ACE2 is reduced whereas glomerular ACE expression is increased. The finding that chronic ACE2 inhibition increases UAE suggests that ACE2, likely by modulating the levels of glomerular angiotensin II via its degradation, may be a target for therapeutic interventions that aim to reduce albuminuria and glomerular injury.

Predicting the development of diabetic nephropathy and its progression

Diabetes remains the number one cause of end-stage renal disease worldwide. Only about one third of diabetic patients develop nephropathy, and the risk appears to be, in part, genetically determined. In this article, we review clinical and genetic markers for the development and progression of diabetic nephropathy. Microalbuminuria remains the best available predictor of the subsequent development of nephropathy, even though in recent years it has become clear that less than 50% of individuals with type 1 diabetes progress to overt proteinuria over a period of less than 10 years. It is of great interest for early recognition of risk of nephropathy that small elevations in nighttime blood pressure predict microalbuminuria in type 1 diabetes. Genetic markers for diabetic nephropathy have not been conclusively identified. The occurrence of renal events in diabetic patients, however, appears to be influenced by the angiotensin-converting enzyme (ACE) genotype, with a dominant deleterious effect of the D allele (D/D or I/D) versus I/I genotype. Some patients with the DD genotype also appear less susceptible to the renoprotective effects of conventional doses of ACE inhibitors, suggesting that ACE genotyping might be useful in selecting those patients that could benefit from higher doses of ACE inhibitors and more aggressive treatment to prevent or delay disease progression.

The acute effect of intravenously administered recombinant human erythropoietin on the immune response of uremic patients maintained on regular hemodialysis

The uremic patient on regular hemodialysis (RHD) is subjected to a wide range of immune modulators including the uremic state per se, multiple transfusions and exposure to bioincompatible materials and endotoxins. Erythropoietin (EPO) therapy may raise concern about its potential influence on this complex scenario. To envisage this issue, 15 adequately selected patients, stable on RHD, were randomly assigned in a 2:1 ratio into EPO and placebo groups. After initial assessment and determination of baseline values, they received, in a double-blind manner, either EPO or normal saline as an intravenous bolus immediately after termination of dialysis for 30 successive sessions. Thirty minutes later, following sessions 1, 10, 20, and 30, samples were obtained for determination of blood counts, red cell indices, peripheral lymphocyte counts (PLC), CD4/CD8 ratios, blood EPO levels, and serum concentrations of interleukins (IL) IL-2r, IL-3, and IL-6, tumor necrosis factor (TNFs and TNFalpha), and neopterin (NPT). Blood EPO levels displayed the predicted rise in the EPO group, which correlated with partial improvement of red cell parameters. The mean total leukocyte count and PLCs was significantly increased in the EPO group (p < 0.05) but not in the placebo group. CD4/CD8 ratios were not significantly changed in either group. The serum concentrations of IL-2r, IL-3, and NPT remained fairly stable while that of IL-6 was widely variable in both study groups. The mean serum concentrations of TNF and particularly TNFalpha showed a steady and statistically significant increment in the EPO group from 6 to 41 pg/ml (p < 0.05) and 93 to 128 pg/ml (p < 0.03), respectively. No significant change was noticed in the control group. It is concluded that intravenous administration of EPO under the conditions of this study may have an immune stimulating effect. This is shown by the release of TNFs, which in turn may be responsible, through different potential mechanisms, for the increase in the mean peripheral neutrophil count and the blunting of erythroid responsiveness to EPO therapy.