bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1601: Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma
Authors: Yang Guozhen , Su Xiaodong , Yang Hong , Luo Guangyu , Gao Chan , Zheng Yating , Xie Wenzhuan , Huang Mengli , Bai Yuezong , Wang Zhiqiang , Cai Peiqiang , He Haoqiang , Xiang Jin , Cai Muyuan , Zhang Yijun , Qu Chunhua , Fu Jianhua , Liu Qianwen , Hu Yi , Zhong Jiudi , Huang Yuanheng , Guo Qiyu , Zhang Xu
Published: July 2021

Background: Immunotherapy is effective in treating unresectable esophageal squamous cell carcinoma (ESCC), but little is known about its activities in the preoperative setting. We aimed to evaluate the safety, feasibility and efficacy of neoadjuvant treatment with camrelizumab plus chemotherapy in locally advanced ESCC.

Methods: Patients diagnosed with locally advanced ESCC were retrospectively included if they had received three courses of neoadjuvant camrelizumab plus nab-paclitaxel and S1 capsule followed by radical esophagectomy between November, 2019 and June, 2020 at Sun Yat-sen University Cancer Center. Primary endpoints were safety and feasibility. Pathological response and association between tumor immune microenvironment (TIME)/tumor mutational burden (TMB) and treatment response were also explored.

Results: Twelve patients were included. Neoadjuvant treatment with camrelizumab plus nab-paclitaxel/S1 was well tolerated without any grade 3 or higher toxicities. No surgical delay or perioperative death was reported. Nine patients (75%) responded to the treatment, four with a complete pathological response and five with a major pathological response. Treatment response by radiography was discordant with surgical pathology for five cases while endoscopic ultrasonography was accurate for the entire cohort. Neither programmed death-ligand 1 expression nor TMB was correlated with treatment response. In the TIME, higher abundance of CD56dim natural killer cells was associated with better pathological response in the primary tumor while lower density of M2-tumor-associated macrophages was associated with better pathological response in the lymph nodes.

Conclusions: Neoadjuvant camrelizumab plus nab-paclitaxel and S1 is safe, feasible and effective in locally advanced ESCC and is worth further investigation.

Citation Format: Guozhen Yang, Xiaodong Su, Hong Yang, Guangyu Luo, Chan Gao, Yating Zheng, Wenzhuan Xie, Mengli Huang, Yuezong Bai, Zhiqiang Wang, Peiqiang Cai, Haoqiang He, Jin Xiang, Muyuan Cai, Yijun Zhang, Chunhua Qu, Jianhua Fu, Qianwen Liu, Yi Hu, Jiudi Zhong, Yuanheng Huang, Qiyu Guo, Xu Zhang. Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma [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 1601.
Abstract 1603: Discover potent and functional human antibodies against a new B7-family member target for cancer immunotherapy
Authors: Wu Xiaodong , Wang Yongqiang , Lv Xiaocheng , Chen Fei , He Yun , Zhao Jiuqiao , Rong Yiping
Published: July 2021

Immunotherapeutics targeting immune checkpoints such as PD1/PD-L1 and CTLA4 offer effective treatment alternatives to the traditional cancer therapies. However, a considerable proportion of patients remain unresponsive to treatment indicating that a more complex immune suppressive tumor microenvironment is involved. Developing novel immune checkpoint inhibitors for combination with current approaches can provide more efficient therapies and expanded indications. A novel B7 family member B7y was recently reported to be highly expressed on a variety of human cancers such as colon, pancreas, breast, bladder, lung cancers and associated with metastatic disease and poor survival. Its co-inhibitory function makes it a new checkpoint and candidate for cancer immunotherapy other than PD-L1 or other immune checkpoints. Here we report the development of functional antibodies targeting this novel B7 family member with potent anti-tumor effect. Generated with H2L2 Harbour Mice® platform, these fully human anti-B7y antibodies specifically bind to cell lines that over-express human or cynomolgus B7y, as well as human tumor cell lines that express endogenous B7y, with high selectivity against other B7 family members. Antibodies that blocked the interaction between B7y and its receptors potently promoted T cell activation in vitro dependent on B7y expression on APC cells. Furthermore, these antibodies in ADCC null versions showed potent anti-tumor activity in humanized murine tumor model. In conclusion, we generated highly potent human antibodies targeting the new immune checkpoint B7 family member and showed good anti-tumor efficacy. Anti-B7y antibody presents a promising novel anti-tumor agent as monotherapy and/or combination therapy with currently established IO agents.

Citation Format: Xiaodong Wu, Yongqiang Wang, Xiaocheng Lv, Fei Chen, Yun He, Jiuqiao Zhao, Yiping Rong. Discover potent and functional human antibodies against a new B7-family member target for cancer immunotherapy [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 1603.
Abstract 1609: Peripheral NK-cell immunophenotypes predict progression in nasopharyngeal carcinoma patients
Authors: Li Xiao-Yun , Lu Zi-Jian , Mai Hai-Qiang
Published: July 2021

Objective: The tumorigenesis is closely associated with the alteration in the expression of cell-surface proteins. As NK cells play a vital role in cancer immunotherapy, we thus conducted this study to characterize the immunophenotypes of circulating NK cells and to explore the association between NK phenotypes and disease prognosis.

Methods: 249 nasopharyngeal carcinoma (NPC) patients and 11 healthy individuals were recruited in the study, whose peripheral blood samples were collected before treatment. Multi-color flow cytometry analysis was performed. The expression of four inhibitory receptors, PD-1, TIGIT, LAG-3, TIM-3, and four stimulatory receptors, NKp46, NKp30, CD226, NKG2D, were measured in three NK subsets, identified by the co-expression of CD56 and CD16 when gated on CD3-. The LASSO (least absolute shrinkage and selection operator) logistic regression model was used to screen out potential prognostic NK subtypes and calculate the NK-function index.

Results: NPC patients exhibited distinct peripheral NK-cell distribution and altered expression of key receptors, as characterized by increased expression of PD-1 and TIGIT on CD56+CD16- cells and decreased expression of NKp46 on CD56+CD16- and CD56-CD16- cells. Four markers were selected from the LASSO model to calculate the NK-function index: PD1 and NKp46 on CD56-CD16+ NK cells, NKp46 on CD56+CD16- cells and NKG2D on CD56+CD16+ cells. Patients with low NK index had significantly shorter progression-free survival (PFS) and distant metastasis-free survival (DMFS), and the NK-function index was an independent prognostic factor for NPC patients.

Conclusions: The immunophenotype of peripheral NK cells and its association with survival outcomes of NPC patients revealed its potential as a strong prognosticator for PFS and DMFS, and highlighted the important role of circulating immune environment, especially for the application of immunotherapy.

Citation Format: Xiao-Yun Li, Zi-Jian Lu, Hai-Qiang Mai. Peripheral NK-cell immunophenotypes predict progression in nasopharyngeal carcinoma patients [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 1609.
Abstract 164: Development of DeepCytoFlow: A novel deep learning pipeline enabling automated gating of flow cytometry data
Authors: Chandran Arjun , Tsau Jennifer , Gaddis Dalia , Sarikonda Shyam , Dakappagari Naveen , Laing Christian , Thomas Swetha Ann
Published: July 2021

Introduction

Following the advent of cellular therapies, flow cytometry has become a central tool for simultaneous assessment of drug levels and disease burden due to its ability for high dimensional cellular analysis. However, identification and monitoring of myriad immune- and leukemic cell phenotypes requires a manual gating process by subject matter experts. Although this process is the current gold standard for flow data analysis, it is slow, tedious, and prone to subjectivity. Herein, we describe our approach to automate flow data analysis using novel strategies that reduces the reliance on clustering methods that are unable to filter challenging noisy data sets inherent in flow data.

Methods

We developed DeepCytoFlow, a novel deep learning framework adapted for flow cytometry data analysis. DeepCytoFlow utilizes a convoluted neural network structure to analyze flow cytometry data files to generate appropriately gated cell populations in a matter of minutes significantly reducing the time required for manual analysis. The neural networks were first trained using a unique data set generated manually by multiple operators and tested using an independent data set to establish concordance in assessments. In addition, we evaluated the performance of our method using both accuracy and F1-score.

Results

Our integrated DeepCytoFlow pipeline employing neural network design shows promise on clustering-based analysis methods in terms of accuracy, precision and recall. More specifically, DeepCytoFlow is capable of correctly classifying various immune cell lineages (e.g., CD4 and CD8 T-cells). However, a limitation was observed on its ability to classify rare cell populations with a very limited prevalence. In an effort to improve performance, we are currently designing a new network architecture, and increasing our training and test dataset's size and quality.

Conclusions

DeepCytoFlow provides proof of concept of the applicability of deep learning for automation of gating in flow cytometry. The high adaptability of deep learning to a large set of problems suggests that this technique can be broadly applied to a larger set of biomarkers for the purpose for automated gating. With additional improvements, we believe DeepCytoFlow can enable a fast, accurate, and robust platform for analysts to perform consistent and, repeatable flow analysis for biomarker monitoring in clinical trials investigating novel immunotherapies.

Citation Format: Arjun Chandran, Jennifer Tsau, Dalia Gaddis, Shyam Sarikonda, Naveen Dakappagari, Christian Laing, Swetha Ann Thomas. Development of DeepCytoFlow: A novel deep learning pipeline enabling automated gating of flow cytometry data [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 164.
Abstract 1645: Cell-based reporter bioassays for the development of Fc-functional and Fc-silent SIRPα/CD47 checkpoint inhibitors
Authors: Mitchell Jonathan , Grailer Jamison , Hartnett Jim , Fan Frank , Cong Mei , Cheng Zhijie Jey
Published: July 2021

CD47, a membrane glycoprotein commonly overexpressed in human cancers, interacts with its cognate receptor SIRPα on myeloid cells to deliver a “don't eat me” signal that inhibits phagocytosis. This SIRPα/CD47 interaction has emerged as a critical and potentially druggable immune checkpoint. Blockade of SIRPα/CD47 interaction promotes phagocytosis of tumor cells in vitro, and SIRPα/CD47 inhibitors exhibit anti-tumor activity, including synergistic activity with other tumor-targeted mAbs (e.g. rituximab), in vivo. These encouraging pre-clinical data have sparked widespread development of SIRPα/CD47 inhibitors and driven a need for robust functional assays to measure the activity of these therapeutic candidates. Biological activity of SIRPα/CD47 inhibitors is typically assessed via in vitro phagocytosis assays based on imaging or flow cytometry. These low-throughput assays often use primary monocyte-derived macrophages and are inherently prone to donor variability. Additionally, many SIRPα/CD47 inhibitors under development are designed to minimize Fc function to enhance safety and are thus incapable of driving phagocytosis directly. To overcome these limitations, we have developed a pair of reporter-based bioassays for measuring the biological activity of Fc-functional and Fc-silent SIRPα/CD47 inhibitors. These assays utilize a SIRPα-positive monocytic effector cell-line that expresses multiple Fc gamma receptors (FcγRs) and encodes a FcγR-responsive NanoLuc luciferase reporter that is inhibited by SIRPα/CD47 interaction upon co-culture of SIRPα effector cells with CD47-positive target cells. Addition of Fc-functional inhibitors simultaneously disrupts the SIRPα/CD47 interaction and engages FcγRs on the SIRPα effector cells, resulting in NanoLuc reporter activation. To enable testing of Fc-silent inhibitors, we have engineered a second CD47 target cell-line which provides a constitutive activating stimulus to SIRPα effector cells that is restricted by SIRPα/CD47 interaction. Addition of Fc-silent SIRPα/CD47 blockers releases inhibition by SIRPα/CD47, resulting in NanoLuc reporter activation. These newly developed reporter bioassays provide a robust, high-throughput platform to facilitate discovery and development of diverse SIRPα/CD47 checkpoint inhibitors.

Citation Format: Jonathan Mitchell, Jamison Grailer, Jim Hartnett, Frank Fan, Mei Cong, Zhijie Jey Cheng. Cell-based reporter bioassays for the development of Fc-functional and Fc-silent SIRPα/CD47 checkpoint inhibitors [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 1645.
Abstract 1650: MoA-based reporter bioassays enable quantitative potency determination for therapeutic biologics targeting co-stimulatory and co-inhibitory immune checkpoint receptors
Authors: Grailer Jamison , Gilden Julia , Stecha Pete , Garvin Denise , Wang Jun , Beck michael , Hartnett Jim , Fan Frank , cong mei , Cheng Zhi-Jie Jey
Published: July 2021

Immune checkpoint (IC) receptors play critical roles in maintaining immune homeostasis and are emerged as promising drug targets for the treatment of various cancers and autoimmune disorders. Monoclonal antibodies designed to block immune inhibitory receptors PD-1 and CTLA-4 have been approved and showed unprecedented efficacy in cancer treatment. This led to rapid expansion of drug development to many more IC receptors targeted individually or in combination. However, due to the novelty and fast speed, one of the bottleneck during immunotherapy drug development is the lack of quantitative and reproducible functional assays for potency determination when existing methods heavily rely on primary immune cells and the process are labor intensive and highly variable.

To address this need, we developed a panel of cell-based reporter bioassays that can quantitatively measure the potencies of biologics targeting individual IC receptor (e.g. PD-1, LAG-3, BTLA, CTLA-4, TIGIT, TIM-3, ICOS, 4-1BB, CD40), or bispecific molecules targeting two IC receptors spontaneously (e.g. PD-1xTIGIT, PD-1xLAG-3, PD-1xCTLA-4, PD1x4-1BB). These bioassays each consist of an engineered T effector cell line that expresses T cell receptors and IC receptors of interest, and an engineered artificial antigen presenting cells (aAPC) expressing the corresponding ligands for the IC receptors. The T effector cell line also expresses a luciferase reporter driven by response elements/promoter specifically responding to TCR activation which can be co-stimulated or inhibited by the signal from the IC receptors. These bioassays are designed to reflect the mechanisms of action for the drug candidates designed for each IC receptor and the assay signals are specific. They are prequalified according to ICH guidelines and show the precision, accuracy and linearity required for relative potency determination and product stability study under cGMP environments. Therefore, these MoA-based bioassays can serve as value tools for early drug discovery, potency determination and stability study throughout immunotherapy drug development.

Citation Format: Jamison Grailer, Julia Gilden, Pete Stecha, Denise Garvin, Jun Wang, michael Beck, Jim Hartnett, Frank Fan, mei cong, Zhi-Jie Jey Cheng. MoA-based reporter bioassays enable quantitative potency determination for therapeutic biologics targeting co-stimulatory and co-inhibitory immune checkpoint receptors [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 1650.
Abstract 1657: Tumor selective immunotherapy to overcome checkpoint blockade resistance
Authors: Jiang Lingxiang , Hergenrother Paul J. , Huang Xiumei
Published: July 2021

Most patients are resistant to PD-1/PD-L1 blockade therapy but mechanisms are not well defined. Defective innate sensing limits reactivation of T cells after the blockade. Patients with well-established solid tumors often generate complicated immunosuppressive networks and are generally refractory to immunotherapy. NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase elevated (more than 100-fold) in most solid cancers and has emerged as a promising target for direct tumor-killing. Here, we demonstrate that novel NQO1 targeting drug-Isobutyldeoxynyboquinone (IB-DNQ) causes tumor-selective innate sensing leading to T cell dependent tumor suppression. IB-DNQ treatment increases PD-L1 expression in the tumor microenvironment. Upregulated PD-L1 within TME contributes to tumor relapse and provides therapeutic window for combination therapy of IB-DNQ with immune checkpoint blockade. We demonstrate that IB-DNQ or PD-1 blockade treatment alone leads to tumor rejection in mice bearing small but not large established tumors. However, combination therapy of IB-DNQ with anti-PD-L1 eradicates well-established and checkpoint blockade refractory tumors.

Citation Format: Lingxiang Jiang, Paul J. Hergenrother, Xiumei Huang. Tumor selective immunotherapy to overcome checkpoint blockade resistance [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 1657.
Abstract 1676: A comprehensive whole blood CyTOF immune monitoring panel with expanded surface and intracellular markers using the Maxpar Direct Immune Profiling Assay
Authors: Mujib Shariq , Li Stephen K. , Zabinyakov Nick , Loh Christina
Published: July 2021

In-depth monitoring of the immune response to cancer and infection is vital to ascertain disease status and to assess immunotherapeutic options. Time-of-flight technology, the basis of CyTOF® mass cytometry, enables multiplex proteomic cellular phenotyping with 50 or more markers, making it ideal for comprehensive immune profiling. Unlike fluorescence-dependent approaches, which require signal compensation that makes the development of larger panels more challenging, CyTOF utilizes monoisotopic metal-tagged antibodies that exhibit minimal background signal, enabling the highest-resolution multiparametric landscape of a single cell. The Maxpar® Direct™ Immune Profiling Assay™ is a pre-titrated dried-down 30-antibody cocktail preparation for immune profiling of human whole blood or PBMC. This assay is used with Maxpar Pathsetter™ software, which resolves whole blood into 37 immune populations comprising major lineage populations and their subsets, such as CD4 Th subsets and B and T cell memory cells, as well as stratifications of myeloid populations. The resulting system is a simple sample-to-answer solution for immune monitoring studies. Here, we expanded the 30-marker assay with 14 additional antibodies comprising pertinent targets of immunotherapy, including the exhaustion markers PD-1, PD-L1, Tim-3 and CTLA-4, and co-stimulation markers 4-1BB and ICOS. We also demonstrated the compatibility of the assay with downstream intracellular staining for cytoplasmic markers IFN-γ, TNF-α, IL-2, perforin and granzyme B for assessment of cellular function in 4h PMA/ionomycin-stimulated whole blood cultures. Next, we modified the existing Pathsetter model to automate the analysis of whole blood stained with the expanded panel to generate reports on key immune cell populations, percentages of exhausted cells and cell subsets producing cytokines. Last, to demonstrate the ability of this expanded panel to identify antigen-specific T cell subsets accompanied by their in-depth phenotypic assessment, we tested this panel against CMV peptide-stimulated whole blood samples. We demonstrated the flexibility of the Maxpar Direct Immune Profiling Assay in panel customization and a streamlined workflow for automated analysis to enable comprehensive immune profiling of human whole blood. For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Shariq Mujib, Stephen K. Li, Nick Zabinyakov, Christina Loh. A comprehensive whole blood CyTOF immune monitoring panel with expanded surface and intracellular markers using the Maxpar Direct Immune Profiling 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 1676.
Abstract 168: Computational model for prediction of actionable drug combinations in cancer
Authors: Pentaparthi Sairahul , Burgman Brandon , Yi S. Stephen
Published: July 2021

Synthetic essentiality presents an effective approach towards finding connected genetic targets in cancer by identifying genes that produce an inviable phenotype upon joint inactivation. However, it is less studied how synthetic lethal gene pairs may be contextualized with respect to deregulation of different cell functions and how these pairs act in different cell types and tissues. To study cancer-specific synthetic essentiality, we devised an integrated network-based algorithm to analyze relationships between tumor gene expression and patient survival in The Cancer Genome Atlas (TCGA) and expression data from the Genotype-Tissue Expression (GTEx) project. In particular, we identify gene pairs in each cancer cohort that exhibit upregulation in tumors but are associated with improved survival for patients whose tumors feature reduced expression of the gene pair. Our findings reveal variability in synthetic lethal pair activity across different cancer types, and the identified pairs connect distinct signaling and metabolic cellular pathways to different cancer types. Altogether, our findings present a pan-cancer reference for gene expression-based synthetic lethal gene pairs as well as a nuanced perspective on changes in synthetic essentiality across different cellular and tissue contexts, pointing to a new avenue for drug combination discovery oriented on targeting key pathways based on the cancer type.

Citation Format: Sairahul Pentaparthi, Brandon Burgman, S. Stephen Yi. Computational model for prediction of actionable drug combinations in cancer [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 168.
Abstract 1686: Host intrinsic STING is a promising biomarkerfor predicting clinical efficacy of anti-PD-1 inhibitors in lung cancer
Authors: Zhou Li , Xu Qiuli , Huang Litang , Zhan Ping , ye mingxiang , Lv Tangfeng , Song Yong
Published: July 2021

Background: The stimulator of IFN genes (STING) signaling pathway plays an important role in anti-tumor immune responses. However, the mechanistic contribution of host and tumor STING signaling to the therapeutic efficacy of anti-PD-1 inhibitors in lung cancer remains unknown.

Methods: We analyzed the association of STING with immune makers in TCGA datasets; we evaluated the efficacy of anti-PD-1 inhibitors by coculturing spleen cells with LLC cells in vitro, and inoculating wild type/STING knockdown LLC cells into the flank of wild-type/STING knockout mice in vivo. Furthermore, we measured the expression of STING by multiple immunohistochemistry and immunohistochemistry in lung cancer patients, and analyzed the relationship between expression level of STING in different cells and treatment efficacy of DCB(Durable clinical benefit : CR or PR or SD lasting longer than 6 months) and NDB(No durable clinical benefit : PD or SD that lasted ≤ 6 months) patients receiving immunotherapy.

Results: Here we first demonstrated that STING signaling pathway activation was associated with better immunotherapy efficacy in lung cancer patients. Next, we identified two distinct STING expression pattern and found that STING in host cells not in tumor cells was positively correlated with infiltration of CD8+ T cells. More importantly, we demonstrated a loss of therapeutic efficacy of anti-PD-1 inhibitor in STING KO spleen cells and STING KO mice. In contrast, knock down of STING expression in tumor cells had no effect. Furthermore, expression of STING on host cells not in tumor cells was correlated with the efficacy of Anti-PD-1 inhibitors in lung cancer patients.

Conclusion: Together, these findings demonstrate that STING expressed in host cells, rather than on tumor cells, plays an essential role in anti-PD-1 inhibitor therapy, suggesting that host intrinsic STING could be predictive of sensitivity to anti-PD-1 inhibitors.

Citation Format: Li Zhou, Qiuli Xu, Litang Huang, Ping Zhan, mingxiang ye, Tangfeng Lv, Yong Song. Host intrinsic STING is a promising biomarkerfor predicting clinical efficacy of anti-PD-1 inhibitors in lung cancer [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 1686.
Abstract 1703: Development of NAV-005, a humoral immuno-suppressor antagonist for the treatment of CA125-expressing cancers
Authors: Nicolaides Nicholas C. , Kline Brad , Grasso Luigi
Published: July 2021

Tumors employ a variety of mechanisms to avoid host cellular and humoral immune responses. Recent findings have found that the tumor-produced MUC16/CA125 protein elicits humoral immunosuppressive effects on antibody-mediated tumor cell killing. This effect is facilitated via direct binding to SIGLEC regulatory receptors on natural killer (NK) cells as well as through direct binding to therapeutic antibodies that blocks Fc-γ-receptor and C1q antibody engagement, leading to suppressed antibody dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC) activities, respectively. We have engineered a human IgG1 Fc fusion protein, called NAV-005, that binds to CA125 with high affinity and blocks its binding to SIGLEC receptors and affected antibodies, thus enabling efficient humoral immune mediated tumor cell killing. NAV-005 is being developed as a novel therapeutic agent to treat humoral immuno-suppressed CA125 expressing cancers.

Citation Format: Nicholas C. Nicolaides, Brad Kline, Luigi Grasso. Development of NAV-005, a humoral immuno-suppressor antagonist for the treatment of CA125-expressing cancers [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 1703.
Abstract 1707: Increasing immune cell infiltration in hepatocellular carcinoma tumors using a novel GPC3-targeting aptamer conjugate
Authors: McGuire Christina , Yuan Jin , Ball Aaron , Sonberg Justin , Wang Yuxun , Thompson Kristin , Zhu Shuhao
Published: July 2021

Glypican 3 (GPC3) is a cell membrane-bound heparin sulfate proteoglycan, expressed at the cell surface of many cancer types. It has emerged as a leading target for hepatocellular carcinoma treatment due to its overexpression in aberrant liver cells and low expression in healthy adult tissues. One of the major challenges in treating hepatocellular carcinoma with current immunotherapies is turning cold tumors into immunogenic ones. Unmethylated CpG oligodeoxynucleotides (ODNs) are known immune stimulators, however their use in combination therapy for cancer treatment is limited due to the requirement of intra tumoral injections to prevent systemic toxicity. Here, we describe a unique GPC3-specific aptamer, able to target GPC3-expressing cancer cells in vivo as a means to deliver the immunostimulatory CpG 7909. Systemic administration through intra peritoneal (i.p.) injection of the GPC3 aptamer-CpG conjugate (GRX51) decreases Hep3B tumor volume in a Balb/c nude mouse xenograft model by ~30-50% depending on treatment schedule, while also increasing immune cell infiltration. Final tumor volumes of GRX51-treated animals are consistent with tumor volumes of animals treated with the standard of care compound, sorafenib tosylate. Due to its GPC3-targeting capacity, systemic dosing of GRX51 (15 mg/kg) is less toxic than systemic administration with equimolar amounts of CpG 7909 alone (5 mg/kg), with a comparable effect on tumor shrinkage. While both GRX51 and CpG 7909 induce immune cell recruitment, GRX51 treated mice had a final immune:tumor cell ratio of 2.45 ± 0.56, while CpG 7909-treated animals had a ratio of 1.51 ± 0.95 relative to the vehicle control after a 7-day on/7-day off daily dosing schedule. Using the Hep3B xenograft in CD34+ humanized mice, we also showed GRX51 primes tumors for combination treatments with FDA approved checkpoint inhibitors. Mice were treated with GRX51 (7.5 mg/kg daily i.p. dose, 11 days), the PD-1R inhibitor pembrolizumab (10 mg/kg once every 3 days i.p., 11 days), or a combination of the two drugs. The GRX51 treatment alone outperformed pembrolizumab alone, reducing tumor size by 33% and 18% respectively. Notably, the combination of GRX51 with pembrolizumab reduced tumor size by 63%. Together, our data show that GRX51 is a novel GPC3-targeting molecule capable of reducing tumor size and priming GPC3-positive tumors for combination immunotherapy, without inducing major systemic toxicity with i.p. injection.

Citation Format: Christina McGuire, Jin Yuan, Aaron Ball, Justin Sonberg, Yuxun Wang, Kristin Thompson, Shuhao Zhu. Increasing immune cell infiltration in hepatocellular carcinoma tumors using a novel GPC3-targeting aptamer conjugate [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 1707.
Abstract 1711: Induction of anti-tumor immunity by intratumoral delivery of mRNA encoding cytokines and TNFRSF agonists
Authors: Gavigan Julie-Ann , Shi Chaomei , Lampa Michael , Malkova Natalia , Yu Qunyan , Qu Hui , Levit Mikhail , Wagenaar Timothy , Hotz Christian , Li Xiangming
Published: July 2021

In the recent decade several immune checkpoint inhibitors, such as anti-PD1/PD-L1 antibodies, have been approved by regulatory authorities and are actively used in oncology clinical practice. However, these antibodies exhibit durable anti-tumor benefits in only a small fraction of cancer patients. A major unmet medical need in immune oncology (IO) is extending the benefits of these therapies to patients who never experience tumor regression (primary resistance) and those who derive initial benefit before experiencing tumor progression (acquired resistance). Novel IO combinations have the potential to both sensitize primary resistant tumors and combat the acquisition of resistance to checkpoint inhibition. Synthetic, in vitro transcribed messenger RNA (mRNA) is an emerging therapeutic modality that offers the ability to express a broad range of therapeutic combinations. In this project, we proposed to ignite anti-tumor immunity locally through intratumoral (i.t.) delivery of a mixture of mRNAs encoding cytokines and a TNF receptor superfamily (TNFRSF) agonist. Using in vitro and in vivo screening, we identified a combination therapy consisting of three cytokines IFNα, IL-7, and a fusion protein of IL-15 with its receptor alpha chain as well as one TNFRSF agonist, an Fc fusion hexameric OX40L for enhanced receptor clustering. The mRNA mixture enhanced human antigen-specific T cell responses in vitro and displayed potent anti-tumor efficacy in syngeneic tumor models when injected i.t., demonstrating the induction of protective immunity. Importantly, in a preclinical dual-flank syngeneic tumor model, we demonstrated that this protective immunity extended beyond tumors injected with the lead mRNA mixture to control growth of distant untreated lesions. Mechanistically, the lead candidate induced anti-tumor immunity by recruiting dendritic cells to the tumor, leading to activation and expansion of tumor specific CD8 T cells. In summary, this mRNA mixture, encoding IFNα, IL-7, IL-15 and OX40L, induced potent anti-tumor immunity in mice and will be further investigated as a combination partner to overcome resistance mechanisms to immune checkpoint inhibition.

Citation Format: Julie-Ann Gavigan, Chaomei Shi, Michael Lampa, Natalia Malkova, Qunyan Yu, Hui Qu, Mikhail Levit, Timothy Wagenaar, Christian Hotz, Xiangming Li. Induction of anti-tumor immunity by intratumoral delivery of mRNA encoding cytokines and TNFRSF agonists [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 1711.
Abstract 1713: Novel, potent and orally bioavailable small molecule CD73 inhibitors for cancer immunotherapy
Authors: Venkateshappa Chandregowda , Narayanan Kishore , Kothandaraman Prasath , Priyadarshani Garima , Nair Rashmi , Goyal Megha , Ahuja Vijay Kamal , Dadhania Sagar , Aravind AB , Samiulla DS , Daginakkatte Girish , Antony Thomas , Nellore Kavitha , Panigrahi Sunil , Chikkanna Dinesh , Samajdar Susanta , Ramachandra Murali
Published: July 2021

CD73 is a cell surface ectoenzyme, which is overexpressed in many types of human and mouse cancers. CD73 is the primary enzymatic producer of immunosuppressive adenosine in the tumor microenvironment, and high CD73 expression is associated with significantly poorer prognosis in several tumor types. Inhibition of either adenosine generation or signaling by inhibiting CD73 have been shown to be effective therapeutic approaches. Here we sought to discover and develop novel and orally bioavailable small molecule inhibitors that target CD73. Aurigene's non-nucleotide small molecule exhibit potent inhibition of CD73 in respective biochemical and cellular assays. High potency translated into rescue of AMP induced repression of IFN-Υ and IL-2 in human PBMCs. Lead compounds exhibited desirable drug-like properties including solubility, Caco2 permeability, lack of CYP inhibition and excellent oral pharmacokinetic exposure. In summary, we have identified small molecule inhibitors with good drug like properties, which showed good in vitro potency and excellent PK. Evaluation of these lead compounds in syngeneic tumor model along with in vivo toxicity studies are currently under way.

Citation Format: Chandregowda Venkateshappa, Kishore Narayanan, Prasath Kothandaraman, Garima Priyadarshani, Rashmi Nair, Megha Goyal, Vijay Kamal Ahuja, Sagar Dadhania, AB Aravind, DS Samiulla, Girish Daginakkatte, Thomas Antony, Kavitha Nellore, Sunil Panigrahi, Dinesh Chikkanna, Susanta Samajdar, Murali Ramachandra. Novel, potent and orally bioavailable small molecule CD73 inhibitors for cancer immunotherapy [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 1713.
Abstract 1715: First in class inhibitors of ERAP1 have the potential to be a transformative immunotherapy in oncology
Authors: Leishman Andrew , Poynton Fergus , Ternette Nicola , Lori Elisa , de Almeida Camila , Leonard Henry , Reeves Emma , James Edd , Clark Kristopher , Tong Carmen , Shiers Jason , Quibell Martin , Joyce Peter Ian
Published: July 2021

Clinical data demonstrates increased antigen presentation diversity is an important factor in determining response rates to checkpoint inhibitors. In addition to tumor mutational burden, increased HLA heterozygosity and HLA evolutionary diversity are non-overlapping factors which further diversify the immunopeptidome and improve clinical response to checkpoint therapies. Endoplasmic reticulum aminopeptidase 1 (ERAP1) is an enzyme that trims peptides loaded into classical and nonclassical MHC Class I molecules. Human genome-wide association studies have identified single nucleotide polymorphisms within ERAP1 that are associated with immune-related diseases, such as ankylosing spondylitis, providing human genetic validation for ERAP1's role in human disease and antigen presentation. Further, ablation of mouse ERAAP modifies the immunopeptidome, resulting in improved immunogenicity, generation of CD8+ T cell responses and tumor growth inhibition.

Grey Wolf Therapeutics have developed highly potent and selective ERAP1 inhibitors. These inhibitors demonstrate significant modulation of the cancer-related antigen repertoire across diverse ERAP1 and HLA genotypes and cancer-type backgrounds, both in vitro and in vivo. These changes in the antigen repertoire drive changes in T cell activation and response, leading to increased T cell infiltration into CT26 syngeneic tumors and T cell receptor (TCR) diversification when combined with anti-PD-1. We have identified immune related markers that are modulated following ERAP1 inhibition in syngeneic tumor models which have the potential to be used as biomarkers. Importantly, ERAP1 inhibitor induced immunopeptidome and T cell changes lead to significant tumor growth inhibition in syngeneic mouse models when combined with anti-PD-1. In parallel, we have demonstrated the ability of ERAP1 inhibitor induced novel cancer associated antigens to stimulate human CD8+ T cell responses. Extensive assessment of the potential of ERAP1 inhibitors to enhance tumor immune responses in combination with additional therapies (e.g. chemotherapy and radiotherapy), across different tumor microenvironments, is ongoing. These data provide the foundation from which we plan to explore the potential of our first-in-class ERAP1 inhibitor development candidate in the clinic.

Citation Format: Andrew Leishman, Fergus Poynton, Nicola Ternette, Elisa Lori, Camila de Almeida, Henry Leonard, Emma Reeves, Edd James, Kristopher Clark, Carmen Tong, Jason Shiers, Martin Quibell, Peter Ian Joyce. First in class inhibitors of ERAP1 have the potential to be a transformative immunotherapy in oncology [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 1715.
Abstract 1722: Enhancement of anti-tumor T-cell immunity by means of an oral small molecule targeting the intracellular immune checkpoint MAP4K1
Authors: Leder Gabriele , Carretero Rafael , Mowat Jeffrey , Berndt Sandra , Neuhaus Roland , Font Nuria Aiguabella , Boemer Ulf , von Ahsen Oliver , Eberspaecher Uwe , Guenther Judith , Grees Mareike , Link Corinna , Nicke Barbara , Baumann Daniel , Schaefer Martina , Oezcan-Wahlbrink Mine , Werbeck Nicolas D. , Hartung Ingo , Kreft Bertolt , Offringa Rienk
Published: July 2021

Immune checkpoint blockade using antibodies targeting the cell surface expressed proteins CTLA-4, PD-1 and PD-L1 has revolutionized cancer care and its clinical impact in several indications has prompted a search for complementary immunostimulatory approaches that can further increase the efficacy of these drugs. Mitogen-activated protein kinase kinase kinase kinase 1 (MAP4K1; HPK1), a serine/threonine kinase expressed exclusively in hematopoietic cell lineages, mediates a negative feedback signal downstream of T-cell receptor stimulation. Its activity is enhanced by PGE2 and TGFβ, factors commonly present in the tumor microenvironment. Mice deficient for MAP4K1 or expressing a kinase-dead variant of MAP4K1 exhibit enhanced T-cell function, including increased anti-tumor immunity. We developed the small molecule inhibitor BAY-405 that displays potent nanomolar MAP4K1 inhibition in biochemical and cellular assays, good kinase selectivity, and in vivo exposure after oral dosing. Pharmacological inhibition of MAP4K1 enhances T-cell immunity and overcomes the suppressive impact of PGE2, TGFβ and CD4+ T-regulatory cells. Single agent treatment of tumor-bearing mice results in suppression of tumor outgrowth in several syngeneic models. This is accompanied by an increase in the anti-tumor T-cell response, dependent on an intact T-cell compartment, while not involving direct anti-tumor cytotoxicity. Inhibition of MAP4K1 in conjunction with PD-L1 blockade results in further suppression of tumor outgrowth. Moreover, we found that MAP4K1 is expressed in both PD-L1-high and PD-L1-low human cancers. In summary, our data show that selective inhibition of MAP4K1 by means of small molecule drugs may be used to expand the patient population responding to immune checkpoint inhibition.

Citation Format: Gabriele Leder, Rafael Carretero, Jeffrey Mowat, Sandra Berndt, Roland Neuhaus, Nuria Aiguabella Font, Ulf Boemer, Oliver von Ahsen, Uwe Eberspaecher, Judith Guenther, Mareike Grees, Corinna Link, Barbara Nicke, Daniel Baumann, Martina Schaefer, Mine Oezcan-Wahlbrink, Nicolas D. Werbeck, Ingo Hartung, Bertolt Kreft, Rienk Offringa. Enhancement of anti-tumor T-cell immunity by means of an oral small molecule targeting the intracellular immune checkpoint MAP4K1 [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 1722.
Abstract 1726: Preclinical evaluation of a novel tumor selectively targeted and activated immunocytokine platform
Authors: Trinh Kham R. , Vasuthaswat Alex , Ayoub George , Morrison Sherie L. , Stover David R.
Published: July 2021

Interferon alpha (IFNα) is a potent cytokine with receptors expressed universally on virtually all cells types. Recombinant versions of IFNα have demonstrated efficacy in multiple tumor indications and have been FDA approved for treatment of various cancers. However, the full anti-tumor potential of IFNα is not realized with these therapies due to dose limiting toxicity, primarily represented by severe flu-like symptoms resulting from systemic activation of immune cells. Antibody-cytokine fusion proteins have been evaluated as an approach to enhance tumor delivery of the cytokine and thereby increase the therapeutic window. While this approach has merit and can increase the efficacy of such constructs, it typically does not reduce the systemic toxicity since the cytokine is still free to interact with its receptor in circulation. We have designed a novel fusion protein in which the IFNα is active only after it has entered the tumor environment, thereby preventing toxicity resulting from systemic activation of IFNα receptors. Direct antitumor efficacy of an anti-CD138-IFNα2 fusion protein with a tumor selectively cleaved peptide mask was seen in models of multiple myeloma and ovarian cancer. The mask was also shown to prevent IFN mediated activation of peripheral blood cells.

Citation Format: Kham R. Trinh, Alex Vasuthaswat, George Ayoub, Sherie L. Morrison, David R. Stover. Preclinical evaluation of a novel tumor selectively targeted and activated immunocytokine platform [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 1726.
Abstract 173: Efficient representations of tumor diversity with paired DNA-RNA aberrations
Authors: Ke Qian , Dinalankara Wikum , Younes Laurent , Geman Donald , Marchionni Luigi
Published: July 2021

In this work we develop a framework which allows for a systematic analysis of joint DNA and putative downstream RNA effects in cancer data cohorts. Using the Reactome database, we extract gene pairs that are linked by known mechanistic connections. Such pairs, which we refer to as 'Source Target Pairs' or STPs, consist of a source gene for which we examine aberrant activity in the DNA profile, and a target gene that is affected by said source gene, for which we examine aberrant activity in the RNA profile.

Using TCGA data for six different cancer types (breast, colon, kidney, liver, lung and prostate), we use mutation and copy number variation information to compile DNA aberrant activity data. For the same cancer cohorts, we use RNASeq gene expression data to quantify RNA aberrant activity via the previous 'divergence' method we have developed. In the divergence framework, normal samples from the same cancer are used to estimate a normal range of expression for target genes of interest and deviation from the normal range is assumed to indicate aberrant activity which may result from upstream DNA aberrations. Then for a given sample, an STP can be represented as a binary variable, indicating presence or absence of joint DNA-RNA aberrant activity.

We utilize integer programming to discover a small set of such STPs for each cancer type such that every sample displays aberrant activity in at least one STP. We refer to these reduced STP configurations as 'minimal coverings' of that cancer. These configurations then allow for the quantification of heterogeneity for that cancer type, as well as for phenotypical groups of interest. This is made possible due to the fact that sample to sample variability can be compared via the entropy of the distribution of the minimal covering, where the small number of STPs in such a configuration makes the computation more tractable.

Our results reveal many known putative drivers of cancer, as well as identify some novel genes of interest for further consideration. Comparison of heterogeneity across phenotypes of interest show higher entropy in more pathological phenotypes, indicating increasing heterogeneity with severity of disease.

Citation Format: Qian Ke, Wikum Dinalankara, Laurent Younes, Donald Geman, Luigi Marchionni. Efficient representations of tumor diversity with paired DNA-RNA aberrations [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 173.