bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-137: Three-dimensional cytotoxicity assay using magnetic 3D bioprinting for measuring CAR T cell function in heterogeneous solid tumor microenvironments
Authors: Souza Glauco R. , Najjar Amer
Published: August 2019

Chromium release assays are routinely utilized to assess cytotoxic activity and function of tumor targeting T cells expressing chimeric antigen receptors (CAR T cells). Although these assays can predict the activity of CAR T cells targeting hematological malignancies, results of such assays do not accurately reflect the limited efficacy of T cell therapy observed against solid tumors. This limitation may be due to the disparity between the in vitro cell culture setting and the complex nature of solid tumor microenvironments and their vascular structure. To this end, we have developed a cytotoxicity assay based on a three-dimensional (3D) cell culture model, facilitated by magnetic 3D bioprinting, to more precisely mimic the complexity of solid tumor microenvironments in vitro. This model can be customized to reflect the heterogeneity of solid tumors by incorporating multiple cell types and immune cells. In these studies, we have demonstrated the feasibility of this assay using CD19-specific CAR T cells specifically targeting CD19+ leukemia cells in a heterogeneous 3D cell culture. We also show the CAR T cells infiltrating and targeting glioblastoma (U87) 3D cultures in real-time with fluorescence microscopy. Incorporation of this assay as a routine cytotoxicity assay will provide new dimensions to rapid immune function assessments by revealing the kinetics of cell killing through time-lapse microscopy, the persistence and targeting patterns of CAR T cells, and cell-specific killing by multicolor fluorescence imaging. This assay is being adapted into a 96-, 384- and 1,536-well formats for high-throughput applications.

Citation Format: Glauco R. Souza, Amer Najjar. Three-dimensional cytotoxicity assay using magnetic 3D bioprinting for measuring CAR T cell function in heterogeneous solid tumor microenvironments [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 LB-137.
Abstract LB-144: Deletion of Map4k4 enhances CD8 T cell function
Authors: Esen Emel , Ye Weilan , Jesudason Rajiv , Sergin Ismail
Published: August 2019

Map4k4 is broadly expressed across different cell types and its function is cell type and context dependent. Although it is expressed in multiple types of immune cells, its specific function in different subsets of lymphocytes and myeloid cells have yet to be determined. Here we demonstrate that reducing MAP4K4 activity can enhance CD8 T cell functions in the context of anti-tumor and anti-viral responses. Inducible deletion of Map4k4 increases CD8 T cell activation, proliferation, cytokine production, and target cell killing in vitro, and enhances CD8 T cell-mediated suppression of tumor growth as well as antigen-specific response to viral infection in vivo. Intratumoral T cells showed evidence of enhanced activation and produced more inflammatory cytokines when stimulated ex vivo. Simultaneously reducing MAP4K4 activity and blocking PDL1 resulted in additive anti-tumor efficacy. Our data suggests that MAP4K4 could be a potential target to augment anti-tumor and immunity.

Citation Format: Emel Esen, Weilan Ye, Rajiv Jesudason, Ismail Sergin. Deletion of Map4k4 enhances CD8 T cell function [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 LB-144.
Abstract LB-145: Investigation of T cell dynamic changes in tumor progression by using sing-cell data
Authors: Zhang Hongyi , Liu Longchao , Chen Jiahui , Li Bo
Published: August 2019

Cancer immunotherapies have revolutionized the treatment of cancer. To better understand the dynamic changes of T cell states during tumor progression, we profiled TCR sequences and transcriptomes of ~40,000 T cells from matched xenograft MC38 cancer cell line and spleen samples of 12 mice. Comparing the gene expression profiles of T cells collected in 10-day and 20-day samples, we observed obvious differences of T cell composition, such as higher CD8 and lower CD4 T cells in 20-day tumors. Unsupervised clustering revealed two subsets of T cells specific to early tumors, recapitulating important markers, such as TCF7, which has recently been reported to be a valid predictor of immune checkpoint blockade therapies in melanoma. Additionally, a unique CD8 cluster, expressing markers of T cell activation and exhaustion, was found to appear only in late tumors. We also observed subpopulations of TCRαβ+ CD3+/CD4-/CD8- double negative (DN) T cells, which have not been well-characterized in the tumor microenvironment. Our analysis revealed three clusters of DN cells: 1) an effector-like group with FCER1G and XCL1 high expression, and high interferon production; 2) a regulatory population expressing high level of Foxp3 and IL2ra, which has been previously reported in autoimmune disorders; 3) a naïve-like population with CCR7 expression. These findings indicate that the DN T cell population may span a wide-spectrum of functionalities that similar to CD4 or CD8 single positive conventional T cells. Our study, for the first time, provided a high-resolution dynamic landscape of T cell state and identified rare T cell subgroups associated with cancer progression.

Citation Format: Hongyi Zhang, Longchao Liu, Jiahui Chen, Bo Li. Investigation of T cell dynamic changes in tumor progression by using sing-cell data [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 LB-145.
Abstract LB-161: Application of the ASCO and ESMO frameworks to TTFields treatment of mesothelioma
Authors: Kelly Justin , Weinberg Uri , Proescholdt Christina
Published: August 2019

Objective: To assess the clinical value of tumor treating fields (TTFields) in malignant pleural mesothelioma (MPM) by means of the ASCO and ESMO frameworks.

Background: The potential effectiveness and safety of TTFields in addition to pemetrexed and cisplatin or carboplatin in MPM was recently shown by the analysis of the Phase II single arm EF-23 STELLAR trial. To account for the need of physicians and policymakers to objectively and comparably capture the clinical value of new cancer treatments the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) have both developed assessment frameworks. We quantified the clinical value of the TTFields treatment in MPM by applying ASCO and ESMO frameworks to the comparison of the STELLAR data to historical controls.

Materials/Methods: The EF-23 STELLAR Trial (n=80) demonstrated that adding TTFields to pemetrexed and cisplatin or carboplatin for malignant pleural mesothelioma patients resulted in overall survival of 18.2 months (95% CI 12.1-25.8) and progression free survival of 7.6 months (95% CI 6.7-8.6). The ESMO Magnitude of Clinical Benefit Scale (MCBS) and the ASCO Net Health Benefit (NHB) frameworks were applied to the EF-23 trial data using a historical control as comparator.

Results: The application of the ASCO framework to the EF-23 data resulted in a NHB score of 52. This result was at the higher end of the score range of novel cancer treatments and compares well to the results for nivolumab in advanced non-squamous NSCLC and advanced squamous NSCLC as reference points. Applying the ESMO framework resulted in MCBS scores of A/5 (adjuvant/advanced) which would be the first score reported for MPM. The MCBS scores of A/5 are the highest scores achievable in the ESMO framework, and higher then the ESMO MCBS scores reported in the literature for NSCLC treatments.

Conclusions: Despite differences in their respective concepts, both the ASCO and ESMO frameworks suggest that adding TTFields to Pemetrexed and Cisplatin or Carboplatin in malignant pleural mesothelioma patients may provide a significant clinical benefit. The high scores underline the fact that treatment with TTFields may extended progression free and overall survival without additional systemic toxicities.

Citation Format: Justin Kelly, Uri Weinberg, Christina Proescholdt. Application of the ASCO and ESMO frameworks to TTFields treatment of mesothelioma [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 LB-161.
Abstract LB-163: Comparing clinical value scores (NCCN, ASCO and ESMO) for TTFields treatment in glioblastoma
Authors: Kelly Justin , Proescholdt Christina , Blondin Nicholas A.
Published: August 2019

Objective: To compare the tools of the National Comprehensive Cancer Network (NCCN), American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) for the assessment of the clinical value for Tumor treating fields (TTFields) in newly diagnosed Glioblastoma (GBM).

Background: The effectiveness and safety of TTFields in newly diagnosed GBM was demonstrated by the final analysis of the randomized controlled EF-14 Trial (n=695). NCCN, ASCO and ESMO have developed tools to help inform physicians and policymakers about the clinical value of new cancer treatments in a standardized way. We report on the results of the tools for scoring the EF-14 trial data and comparatively discuss the results.

Materials/Methods: The EF-14 Trial proved the effect of adding TTFields to maintenance temozolomide (TMZ) for newly diagnosed glioblastoma patients. The ESMO Magnitude of Clinical Benefit Scale (MCBS) and the ASCO Net Health Benefit (NHB) frameworks calculate a score for the clinical value of a cancer treatment. We applied both classifications to the EF-14 trial data. Quality of life data from the EF-14 Trial was also published and is included in the scoring. NCCN self reports “evidence blocks” which are assessed by clinician panels and were recently published for the first line treatment of newly diagnosed GBM.

Results: Applying the ASCO framework to the EF-14 data resulted in a NHB score of 56. This scores is among the highest identified in the literature search. Applying the ESMO framework resulted in MCBS scores of A/5, these being the highest achievable scores for this framework. The ESMO framework valued the Health Related Quality of Life (HRQoL) gain during deterioration-free survival time with TTFields. The NCCN CNS panel designated TTFields as a category 1 recommendation in newly diagnosed GBM; the related NCCN evidence blocks support this recommendation.

Conclusions: While the frameworks used by ASCO and ESMO focus on different aspects and definition of clinical value both suggest that adding TTFields to maintenance TMZ for newly diagnosed glioblastoma patients provides patients with significant clinical benefits. The high ESMO and ASCO scores are reflecting the fact, that treatment with TTFields extended progression free and overall survival without additional systemic toxicities. The NCCN evidence blocks together with the NCCN category 1 recommendation strongly support the use of Optune in newly diagnosed GBM

Citation Format: Justin Kelly, Christina Proescholdt, Nicholas A. Blondin. Comparing clinical value scores (NCCN, ASCO and ESMO) for TTFields treatment in glioblastoma [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 LB-163.
Abstract LB-176: Transcriptome-wide association study revealed a novel gene associated with persistent hepatitis B virus infection among Chinese
Authors: Han Jing , Ni Jing , Zhu Meng , Fu Jin Guang , Hu Zhi Bin
Published: August 2019

The etiology of persistent hepatitis B virus (HBV) infection is complex and multifactorial, polygenic event with viral, environmental and genetic components being considered as the risk factors. Genome-wide association study (GWAS) has been applied into the exploration of genetic etiology of persistent hepatitis B virus infection among Chinese. However, the mechanisms beyond the genetic variants identified by GWAS located in noncoding regions are largely unknown. To further explore the causal gene of persistent hepatitis B virus (HBV) infection, we used a new approach developed by Gusev and Ko, leveraging expression imputation from large-scale GWAS data by using a small set of individuals with both genotype and gene expression data as a reference panel, to perform a transcriptome-wide association study (TWAS).Based on Genotype-Tissue Expression (GTEx) database, we included 97 individuals with both gene expression data in liver and SNP array data in blood as a reference panel. We first estimated the cis SNP heritability (cis-hg2) for each gene in 97 liver tissues using genome-wide complex trait analysis (GCTA) software, and kept cis-heritable genes for subsequent analysis. Then, we estimated the effect sizes of cis-SNPs on gene expression using genome-wide efficient mixed-model association (GEMMA) algorithm. Using the effect sizes trained from the reference panel, we imputed the gene expression levels for our existing NJMU HEP GWAS cohort (951 persistent hepatitis B virus (HBV) infection patients and 937 controls) and correlated the imputed gene expression values with persistent hepatitis B virus (HBV) infection trait. The cis-hg2 estimate was significantly nonzero for 2588 genes (P<0.05). The average cis-hg2value was 0.438. Using GTEx database as a reference panel. In the training set, After FDR correction, we identified three potentially persistent hepatitis B virus (HBV) infection -associated genes, those genes were located in 6p21.3(HLA-DPA1,PTWAS=2.02×10-7), 3q21.1(PARP9, PTWAS=2.2×10-4) and 22q11.21 (TMEM191A, PTWAS= 3.8×10-4)respectively. 6p21.3 and 22q11.21 as our previous reported. 3q21.1 was a novel region.

Citation Format: Jing Han, Jing Ni, Meng Zhu, Jin Guang Fu, Zhi Bin Hu. Transcriptome-wide association study revealed a novel gene associated with persistent hepatitis B virus infection among Chinese [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 LB-176.
Abstract LB-180: Underreporting of race in genomic sequencing studies increases cancer health information disparities
Authors: Nugent Adrienne , Conatser Kelly R. , Turner Llaran L. , Nugent James T. , Sarino Esther May , Ricks-Santi Luisel J.
Published: August 2019

Purpose: Minorities are often underrepresented in clinical cancer research and the frequency of reporting of race in genomic sequencing studies of cancer is unknown. Disproportionate reporting of race can widen health information disparities and impair clinical decision-making in the underrepresented minority populations in whom cancer disease burden is greatest. This study determined the extent to which race is reported as a clinical variable in sequencing studies of cancer in the United States, the factors associated with reporting of race, and the participation rates of minority populations.

Methods: PubMed was systematically searched from January 1, 2010 through November 15, 2018 and a total of 9,410 non-duplicated studies were assessed for eligibility. Publications reporting whole genome or exome sequencing data for patients with one of the ten most common cancers in the United States at sufficient depth to identify rare variants were included in this study.

Results: 234 publications containing sequencing data from 16,358 unique patients met inclusion criteria. 36% of studies reported race as a clinical variable compared to 84% of studies reporting age and 83% of studies reporting gender. Reporting of race was associated with cancer type, cohort size, sequencing method, and tissue acquisition date. Minority populations were significantly underpowered to detect recurrent mutations in the majority of cancer types due to small sample size.

Conclusion: Race is underreported as a clinical variable in whole genome and exome sequencing studies of cancer in the United States. As the patient populations represented in research studies directly inform clinical decision-making and outcomes, substantially increased efforts are needed to sequence patients from underrepresented populations in order to reduce health disparities in patients of non-European ancestry.

Citation Format: Adrienne Nugent, Kelly R. Conatser, Llaran L. Turner, James T. Nugent, Esther May Sarino, Luisel J. Ricks-Santi. Underreporting of race in genomic sequencing studies increases cancer health information disparities [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 LB-180.
Abstract LB-184: The immunotherapeutic role of indoleamine 2,3-dioxygenase (IDO) in head and neck squamous cell carcinoma: a systematic review
Authors: Lin Daniel J. , Ng James C. , Huang Lei , Robinson Max , O'Hara James , Wilson Janet A. , Mellor Andrew L.
Published: August 2019

Background: Novel cancer immunotherapy includes application of immune checkpoint inhibitors to the treatment of solid tumors. The body’s own immune system is thereby harnessed to tip the balance in favor of antitumor activity. The intracellular enzyme indoleamine 2,3-dioxygenase (IDO) is a critical regulator of the tumor microenvironment (TME) via tryptophan metabolism. Programmed death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) are immune checkpoints involved in T-cell inhibition and immunosuppression. Another immune checkpoint, IDO1, breaks down tryptophan into its metabolites which results in immunosuppression in the TME.

Aim: To assess the evidence on IDO in head and neck squamous cell carcinoma (HNSCC).

Methods: Medline, EMBASE using Ovid, Scopus, Web of Science, Cochrane Library databases, and ClinicalTrials.gov were searched from inception until present day.

Results: We included 32 studies. Of those, 5 involved cell lines, 7 assessed tumor immunohistochemistry, 6 measured IDO gene transcription, and 14 reported on clinical trials. The human cell lines studied commonly were SCC4, SCC15, and SCC25 in which IDO expression and activation by the Stimulator of Interferon Genes (STING) pathway played a central role. Retrospective immunohistochemistry studies of lower lip, oral cavity, tongue, tonsil, and larynx found that relatively high IDO expression correlated with worse survival. Gene transcription studies showed increased IDO in tumors that expressed PD-L1 and harbored human papillomavirus (HPV). Phase I/II clinical trials showed 1) objective responses (34%) and disease control rates (62%) for IDO1 inhibitor in combination with a PD-1 inhibitor, 2) consistent safety profile in combination versus monotherapy, and 3) IDO gene expression as a predictive biomarker for response to PD-L1 therapy.

Conclusions: IDO is integral to TME immunity in HNSCC particularly in HPV positive tumors, modulating existing therapies and application in combinatorial immunotherapy. Retrospective studies have shown the presence of IDO in the TME and suggest a link to prognosis and prediction of HNSCC treatment outcome. However, the exact mechanism of IDO-driven immune modulation in the HNSCC TME remains unclear. We now require prospective longitudinal studies to track IDO activity and expression throughout HNSCC treatment, thence optimise IDO-based immunotherapy.

Citation Format: Daniel J. Lin, James C. Ng, Lei Huang, Max Robinson, James O'Hara, Janet A. Wilson, Andrew L. Mellor. The immunotherapeutic role of indoleamine 2,3-dioxygenase (IDO) in head and neck squamous cell carcinoma: a systematic review [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 LB-184.
Abstract LB-188: Breast cancer immunotherapy using magnetized HSV1716
Authors: AL-Janabi Haider , Conner Joe , Howard Faith , Hunt Stuart , Taher Zainab , Staniland Sarah , Muthana Munitta
Published: August 2019

Background: Oncolytic viruses (OV) are encouraging new immunotherapies for cancer. OVs, replicate in cancer cells inducing immunogenic cell death (ICD) and activating antitumor immunity. To date, clinical use has focused on intratumoral delivery due to concerns over inadequate tumor targeting following systemic administration. We hypothesize that magnetizing OVs and magnetic guidance strategies will improve systemic delivery by protecting the viruses from inactivating immune mechanisms and non-specific adsorption.

Methods: To investigate this, we synthesized and characterized complexes of magnetized oncolytic herpes simplex virus (HSV1716) co-assembled with biocompatible magnetic nanoparticles (MAG) derived from magnetotactic bacteria (AMB-1) to give MAG-HSV1716 complexes. Characterization of the physical, chemical and oncolytic potential of our MAG-HSV1716 was performed. The safety and efficacy of our nanomedicine in combination with magnetic guidance strategies were also assessed in vivo.

Results: Stable MAG-HSV1716 complexes of ~160nm diameter successfully infected human and murine breast cancer cells in a dose-dependent manner, and induced tumor oncolysis. Following MAG-HSV1716 infection a significant increase in viral replication (ICP0, gB, ICP8), ICD (HMGB1, CALR, ATP) and apoptotic (CASP 3, CASP8, FASL) signals were detected. Intravenous delivery of MAG-HSV1716 resulted in reduced tumour burden in the presence of magnetic guidance (MAG-HSV1716 448.3mm³ vs. HSV1716 670.6mm³; p ≤ 0.05, n=6-9 mice/group) and an increase in tumor-infiltrating T-cells, NK cells and neutrophils. Furthermore, MAG-HSV1716 were protective in the presence of neutralizing Abs both in vitro and in vivo.

Conclusion: This study indicates that magnetizing HSV1716 results in viral protection from neutralizing antibodies and in combination with magnetic guidance reduces tumor burden and induces anti-tumor immunity.

Citation Format: Haider AL-Janabi, Joe Conner, Faith Howard, Stuart Hunt, Zainab Taher, Sarah Staniland, Munitta Muthana. Breast cancer immunotherapy using magnetized HSV1716 [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 LB-188.
Abstract LB-201: BIL06v immunizations generate antibodies specific for non-functional P2X7 (nfP2X7) that target solid tumors in vivo
Authors: Oliphant Chris J. , Freeman Elle , Gilbert Simon , Lara Romain , Huang Edwin , Barden Julian , McNulty Shaun
Published: August 2019

P2X7 is an ATP-gated purinergic receptor characterized by a biphasic response. Short term exposure to high ATP concentrations triggers opening of a cation channel, whilst prolonged exposure triggers opening of a non-selective pore that disrupts intracellular homeostasis, leading to cell death. Increasing numbers of studies have described a role for P2X7 in malignant tumors, including breast, prostate, colorectal and lung, and P2X7 has been shown to play critical roles in mediating various cancer cellular responses, such as cell proliferation, migration, invasion, and survival. We have described a form of P2X7 that is highly expressed on several cancers, which we term non-functional P2X7 (nfP2X7) that is unable to open a non-selective pore. Non-functional-P2X7 can form when P2X7-expressing cells undergo prolonged exposure to high ATP concentrations found in the local tumor microenvironment. This conformational change results in the exposure of a unique epitope composed of amino acids 200-216, known as the E200 peptide epitope. The E200 peptide epitope has been shown to be a safe and selective target for antibodies against solid tumors. Using the E200 peptide epitope we have prepared a peptide vaccine adjuvanted by Alhydrogel 2%, which we have termed BIL06v, for the therapeutic treatment of solid tumors. A similar vaccination approach was used to generate antibodies for a topical therapeutic that was shown to be safe with indications of efficacy in a Phase 1 clinical trial to treat basal cell carcinoma. Using preclinical in vivo models, we have investigated the tractability of BIL06v as a therapeutic against tumors. In mice and human, BIL06v can break immune tolerance and drive the production of antibodies specific for nfP2X7. A formal toxicology study has demonstrated both immunogenicity and safety in rats following repeated treatment with BIL06v. Furthermore, BIL06v treatment has been shown to improve host outcomes in syngeneic mouse models of disease. Therefore, targeting nfP2X7 with a peptide conjugate vaccine, such as BIL06v, presents a novel and safe therapeutic approach for the treatment of multiple malignancies.

Citation Format: Chris J. Oliphant, Elle Freeman, Simon Gilbert, Romain Lara, Edwin Huang, Julian Barden, Shaun McNulty. BIL06v immunizations generate antibodies specific for non-functional P2X7 (nfP2X7) that target solid tumors in vivo [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 LB-201.
Abstract LB-203: Metformin enhances the efficacy of tumor membrane vesicle (TMV)-based vaccine immunotherapy in a murine model of breast
Authors: Munoz Luis E. , Bommireddy Ramireddy , Huang Haley , Kim Janet , Selvaraj Periasamy
Published: August 2019

Breast cancer remains the most commonly diagnosed cancers among women, with over 250,000 new cases per year in the United States. Immunotherapy has emerged as a promising treatment of breast cancer, however response rates to therapy remain far from ideal. In this study, we investigated the combinatorial effect of tumor membrane vesicle (TMV)-based vaccine immunotherapy, to induce an anti-tumor immune response, with the type 2 diabetes drug metformin, which has been reported to exert anti-tumor effects by maintaining CD8 T cell activity in the tumor microenvironment. Our results show that TMV vaccination inhibits primary tumor growth in preclinical tumor models, while combination with metformin resulted in greater inhibition of primary growth. Importantly, TMV vaccination reduced the metastatic burden in the lungs while combination with metformin further abrogated metastatic spread. Interestingly, TMV vaccination alone induced a significant increase in T cell infiltration to the tumor, while combination with metformin caused a decrease in the accumulation of T cells, despite having better outcomes. Further, we show that metformin is capable of reducing PD-L1 expression within the tumor microenvironment in both tumor cells as well as myeloid-derived suppressor cells, providing insight for the improvement of TMV-based immunotherapy.

Citation Format: Luis E. Munoz, Ramireddy Bommireddy, Haley Huang, Janet Kim, Periasamy Selvaraj. Metformin enhances the efficacy of tumor membrane vesicle (TMV)-based vaccine immunotherapy in a murine model of breast [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 LB-203.
Abstract LB-206: The synergistic antitumor effect of the combination of three transgenes delivered by the oncolytic vaccinia virus, KLS-3020
Authors: Shin Jaeil , Hong Soon-Oh , Kim Minjung , Choi Heonsik , Kim Sujeong
Published: August 2019

Oncolytic viruses that selectively kill cancer cells are a promising platform for fighting cancer. Vaccinia virus is a good candidate for the oncolytic virus because it has several advantages such as a proven safety profile, broad host tropism, and larger capacity to harbor multiple transgenes.

We removed three viral genes (C11R, K3L, and J2R) from wild-type vaccinia virus to obtain a backbone virus, which is selectively replicating in cancer cells. Then, we inserted three transgenes (PH20, sPD1-Fc, and IL-12) into the backbone virus to boost up the antitumor efficacy, which is the final construct named KLS-3020.

We investigated the biological activity of transgenes with the intratumorally injected backbone viruses containing each single transgene in syngeneic mouse tumor models. At first, the backbone virus expressing PH20, an enzyme which can degrade the tumor extracellular matrix, showed enhanced virus spread compared to the empty backbone virus in melanoma or colon cancer. Likewise, locally expressed sPD1-Fc, which is a fusion protein of the extracellular domain of PD-1 and Fc region of an immunoglobulin, resulted in the increase of INF-γ+CD8+ and INF-γ+CD4+ T cells in melanoma, indicating T cell re-activation in the tumor site. Lastly, delivered IL-12 in lung cancer mouse model resulted in a significant increase of T-bet+CD4+ T cell populations, indicating the oriented differentiation of helper T cell into T helper 1 (Th1) cells.

We compared the efficacy of oncolytic vaccinia virus containing a combination of three transgenes (KLS-3020) with ones expressing each single gene in syngeneic mouse tumor models and observed that KLS-3020 could control tumor growth more effectively than every backbone virus having a single gene. Finally, we evaluated the anti-tumor efficacy of KLS-3020 in various types of mouse tumor models. Intratumorally injected KLS-3020 could suppress the growth of various tumors without significant body weight loss. Our results suggest that enhanced virus spread combined with the immune-stimulatory activity of KLS-3020 synergistically increase antitumor efficacy in a broad range of tumor types.

Citation Format: Jaeil Shin, Soon-Oh Hong, Minjung Kim, Heonsik Choi, Sujeong Kim. The synergistic antitumor effect of the combination of three transgenes delivered by the oncolytic vaccinia virus, KLS-3020 [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 LB-206.
Abstract LB-214: Imputation of single cell cancer genotypes
Authors: Zelikovsky Alex , Mandric Igor , Skums Pavel , Mandoiu Ion , Pasaniuc Bogdan , Srivastava Pramod
Published: August 2019

Recent advances in sequencing technologies and emerging single cell sequencing promise to profoundly impact cancer studies. One of the most important problems is reconstruction of history of cancer mutations. Existing methods model cells DNA as haplotypes and reconstruct perfect (or almost perfect) phylogeny of mutations from single cell DNA sequencing data. In this paper we propose to reconstruct genotypes (rather than haplotypes) which in absence of repeated and omitted mutations is equivalent to reconstruction of the mutation phylogeny. Single cell genotype reconstruction is proposed to perform in two steps - first the sequencing data are used for imputation of cell genotypes treated as individual human genomes and then the resulted genomes are fitted to perfect phylogeny by eliminating 4-gamete rule violations using integer linear programs. Our simulation results show advantage of single cell genotype imputation over existing methods.

Note: This abstract was not presented at the meeting.

Citation Format: Alex Zelikovsky, Igor Mandric, Pavel Skums, Ion Mandoiu, Bogdan Pasaniuc, Pramod Srivastava. Imputation of single cell cancer genotypes [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 LB-214.
Abstract LB-219: Derivation of mathematical modeling for the diffusion and penetration of monoclonal antibody delivery into tumor
Authors: Kim Hyeongi , Kim Yangjin , Lee Yong-Jin , Kim Jin-su
Published: August 2019

Background: Commonly malignant solid tumor have an abundant tumor-associated cellular matrix (ECM). Although radioimmunothrepy (RIT) have proven to be effective and precise treatment in cancer, yet RIT has a limited performance in solid tumor, due to highly distributed ECM inside solid tumor tissue. Previously, we designed the combination RIT to enhance the penetration of monoclonal antibody (mAb), where we investigated that, using Relaxin which contain oncolytic adenovirus (OA) as combination therapy decreases tumor associated ECM. In this study, we developed mathematical modeling to explain and describe the diffusion and penetration of mAb inside the tumor with ECM. To obtain the model parameters in our developed mathematical model, we performed related experiments such as immunofluorescence and qRT-PCR.

Methods: We developed the reaction-diffusion partial differential equations (PDE) for describing the dependency of cancer cell, ECM density, diffusion and penetration of mAb and ECM modulated therapy that include our experimental data, also to overcome the classical limitation of PDE method. Model included the rapid decrease of ECM by OA, and density dependent diffusion coefficient. Initial condition for solving the PDE was derived using our experimental result. Diffusion coefficient for mAb and OA was modelled for simulating actual behavior of mAb and OA. Various condition of ECM density, and structure were modelled that derives the actual result of distribution of collagen. To confirm the mathematical prediction, we designed in vitro experiment with same condition as used as “in model”.

Results: Using our developed model, we successfully described relationship between ECM and mAb transport by OA, and investigated the change of ECM. Diffusion and penetration of mAb and OA were well described from tumor vessel and tumor surface. Regardless of ECM structure, all ECM structure were degraded after spreading of OA. In addition, our model simulation results predicted that mAb uptake dramatically increased in combination approach and was more than mAb alone treatment. Our developed mathematical model predicted the optimal schedule of OA pretreatment and it shows great results more than mAb pretreatment. Pretreatment results with OA shows a great anti-tumor effect more than mAb pretreatment in experimental data. Our model could well predicted and matched the experimental results. Collectively, in our study, we suggested new theoretical mathematical model framework to explain various ECM condition with drug transport

Citation Format: Hyeongi Kim, Yangjin Kim, Yong-Jin Lee, Jin-su Kim. Derivation of mathematical modeling for the diffusion and penetration of monoclonal antibody delivery into tumor [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 LB-219.
Abstract LB-258: EGFR and c-MET cooperate to enhance PARP inhibitor resistance in hepatocellular carcinoma
Authors: Dong Qiongzhu , Du Yi , Zhao Xixi , Li Hui , Liu Chunxiao , Wei Yongkun , Hung Mien-chie
Published: August 2019

Poly (ADP-ribose) polymerase-1 (PARP-1) inhibitors are currently used in the clinic for the treatment of ovarian and breast cancers. However, the therapeutic efficacy of PARP inhibitor (PARPi) in the clinical trial for hepatocellular carcinoma (HCC) has been disappointing. To ensure therapeutic efficacy of PARPi against HCC, a disease often diagnosed at intermediate to advanced stages with no effective treatment options, it is critical to identify not only biomarkers to predict PARPi resistance but also rational combination treatments to overcome this. Here, we demonstrate that EGFR forms a heterodimer with c-MET, and the complex interacts with and phosphorylates Y907 PARP1 in the nucleus contributing to PARPi resistance. Inhibition of both EGFR and c-MET sensitizes HCC cells to PARPi. Combination of EGFRi, METi and PARPi significantly inhibited tumor growth in HCC animal model. Both EGFR and c-MET are known to be overexpressed in HCC. The current report provides a rationale to explain why PARPi does not work in clinical trials for HCC and also suggests an effective combination treatment consisting of EGFR, c-Met, and PARP inhibitors for HCC.

Note: This abstract was not presented at the meeting.

Citation Format: Qiongzhu Dong, Yi Du, Xixi Zhao, Hui Li, Chunxiao Liu, Yongkun Wei, Mien-chie Hung. EGFR and c-MET cooperate to enhance PARP inhibitor resistance in hepatocellular carcinoma [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 LB-258.
Abstract LB-266: A novel computational combination-therapy prediction algorithm (secDrug) identifies the Nampt inhibitor FK866 reverses PI-resistant multiple myeloma
Authors: Kumar Harish , Mukherjee Ujjal Kumar , Chakravarti Sayak , Chen Li , ness Brian Van , Mitra Amit Kumar
Published: August 2019

Drug resistance is a major cause of concern in cancer chemotherapy that not only reduces efficacy but also causes toxicity through overdosing. For example, Ixazomib, an oral proteasome inhibitor, has proven to remarkably improve myeloma patient outcomes but is associated with dose limiting toxicities and drug resistance. Therefore, new combination treatment regimens are urgently needed for the treatment of cancers, including multiple myeloma, which can lower the required dose of standard-of-care drug without compromising on treatment efficacy. We will present an optimization-regularization based computational prediction method called secDrug that uses large-scale pharmacogenomics databases to identify novel secondary drug combinations to reverse drug resistance. In this study, we applied secDrug to Ixazomib-resistant cell lines (>100) in the Genomics of Drug Sensitivity in Cancer (GDSC) database and predicted that the following FDA-approved drug classes can be best combined with Ixazomib to overcome resistance in MM: nicotinamide phospho ribosyl transferase or Nampt inhibitor (FK866), HDAC inhibitors (Panobinostat, SAHA), neddylation inhibitor (MLN4924), Raf inhibitor (PLX-4720) and HSP90 inhibitor (17-AAG). Our results corroborate with earlier studies that have indicated these drugs could potentially be used in MM, alone or in combination. To validate our prediction results, we treated our panel of >50 human multiple myeloma cell lines (Ix-sensitive and Ix-resistant HMCLs) with the top predicted drug combination - FK866 + Ixazomib. The results, based on combination index theorem, show that this combination works highly synergistically where the IC50 of ixazomib in MM cells was significantly reduced in presence of FK866. Similar results were obtained for the other top predicted combination regimens. Our findings provide a strong case for using secDrug for predicting secondary drugs in cancers resistant to the standard-of-care therapy. Furthermore, this provides additional evidence in support of combining FK866 with ixazomib to enhance sensitivity or overcome resistance to ixazomib and thereby improve patient outcome. Our future aim is to investigate the mechanism behind the synergism between proteasome inhibitors and the top drugs identified by our algorithm as candidates for secondary combination therapies using next-gen transcriptomics and single-cell approaches.

Citation Format: Harish Kumar, Ujjal Kumar Mukherjee, Sayak Chakravarti, Li Chen, Brian Van ness, Amit Kumar Mitra. A novel computational combination-therapy prediction algorithm (secDrug) identifies the Nampt inhibitor FK866 reverses PI-resistant multiple myeloma [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 LB-266.
Abstract LB-268: Assessment of flat dosing strategy for INCMGA00012 in patients with advanced tumors
Authors: chen Xuejun , Wang Phil , Kaul Sanjeev , Sumrow Bradley , Yeleswaram Swamy
Published: August 2019

Background: INCMGA00012, a humanized, hinge-stabilized, IgG4κ monoclonal antibody that recognizes human PD-1, is being developed for the treatment of multiple solid tumor types, both as monotherapy and in combination with other potentially immunoactive agents. Flat dosing is preferred to weight-based dosing for multiple reasons, including convenience of preparation and administration, reduced errors in preparation calculation, and minimization of drug waste. A modeling and simulation approach was employed to support flat doses for later phase studies.

Patients and Methods: INCMGA00012 has been administered to approximately 200 participants in a Phase 1 study (Study INCMGA 0012-101) at weight-based doses ranging from 1 to 10 mg/kg Q2W or Q4W and at flat doses of 500 mg Q4W and 750 mg Q4W. PK data from weight-based doses were used for population PK model development and data from flat doses were used for model validation. Simulations were performed to support the selection of RP2 flat dose.

Results: The concentrations of INCMGA00012 were adequately described by a 2-compartment model with first-order elimination. Higher clearance was estimated for 1 mg/kg (23.5 mL/h) than the other dose groups (13.5 mL/h). Body weight dependence of clearance and volume of distribution for central compartment were characterized by power relationships with exponents of 0.911 and 0.493, respectively. The model was validated using PK data from participants who received INCMGA00012 500 mg Q4W and 750 mg Q4W, respectively, in the cohort expansion phase. Median steady state trough concentrations of 500 mg Q4W and 750 mg Q4W exceeded the target value.

Conclusion: Modeling and simulation provide justification for 500 mg Q4W for further clinical development of INCMGA00012 based upon favorable safety, PK characteristics and presumed flat exposure-response relationships for efficacy.

Citation Format: Xuejun chen, Phil Wang, Sanjeev Kaul, Bradley Sumrow, Swamy Yeleswaram. Assessment of flat dosing strategy for INCMGA00012 in patients with advanced 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 LB-268.
Abstract LB-277: Characterization of the anti-cancer and immunologic activity of RGX-019, a novel pre-clinical stage humanized monoclonal antibody targeting the MERTK receptor
Authors: Takeda Shugaku , Andreu-Agullo Celia , Sridhar Subhasree , Halberg Nils , Lorenz Ivo C. , Tavazoie Sohail , Kurth Isabel , Tavazoie Masoud
Published: August 2019

MERTK, a receptor tyrosine kinase of the TYRO3/AXL/MERTK (TAM) family, is expressed in innate immune cells including macrophages, dendritic cells and NK cells and is overexpressed in a wide variety of cancers, including leukemia and many solid cancers. Activation of MERTK on cancer cells via ligand binding results in activation of several tumor-promoting signaling pathways, which stimulate proliferation, migration and angiogenesis, and decrease apoptosis and chemosensitivity. Furthermore, activation of MERTK on macrophages drives immune evasion through the promotion of an immune-suppressive M2 phenotype. Pre-clinical and

clinical studies have shown promising emerging evidence of anti-tumor efficacy upon modulation of TAM receptor signaling. Herein, we report the pre-clinical characterization of RGX-019, a humanized IgG1 antibody with high affinity and specificity for human MERTK.

Surface Plasmon Resonance, cell-based binding assays and competition ELISA demonstrate high affinity/avidity binding for RGX-019 to human MERTK. In contrast, binding to human AXL, human TYRO3, or murine MERTK was not detected. Binding of RGX-019 to the MERTK receptor triggered its rapid internalization and degradation from the surface of human cancer cells within 4 hours and prevented Gas6 induced phosphorylation of AKT, a downstream signal transduction pathway that promotes cell growth and survival. RGX-019 treatment of SKMel5 melanoma cells effectively inhibited colony formation. RGX-019-induced degradation of MERTK in in vitro differentiated human M2 macrophages reduced AKT activation and promoted a pro-inflammatory cytokine signature. Furthermore, a related surrogate murine MERTK antibody significantly inhibited growth of MDA-MB-231 breast cancer tumors, demonstrating single agent anti-tumor efficacy in vivo. These findings demonstrate that RGX-019 is a potent and selective inhibitor of MERTK signaling with a unique mechanism-of-action that potently disrupts MERTK signaling in both cancer cells and immune-suppressive macrophages via MERTK receptor degradation. This activity results in robust repression of cancer cell growth both in vitro and in vivo. Overall, these data support further development of RGX-019 as a cancer therapeutic.

Citation Format: Shugaku Takeda, Celia Andreu-Agullo, Subhasree Sridhar, Nils Halberg, Ivo C. Lorenz, Sohail Tavazoie, Isabel Kurth, Masoud Tavazoie. Characterization of the anti-cancer and immunologic activity of RGX-019, a novel pre-clinical stage humanized monoclonal antibody targeting the MERTK receptor [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 LB-277.
Abstract LB-279: Artificial intelligence aided diagnosis of breast cancer molecular classification based on immunohistochemical images
Authors: Zhao Jean J. , Ruan Minzi , Cui Quancai
Published: August 2019

Breast cancer has obvious heterogeneity. Molecular classification of breast cancer has been done through the study of gene expression profile. There were significant differences in gene expression, clinical characteristics, therapeutic response and prognosis among these molecular types, which were lumen A type, lumen B type, her-2 overexpression type and basal cell type, respectively. Compared with other nucleic acid level detection technologies, immunohistochemistry (IHC), as the most commonly used protein expression level detection method, has the advantages of low price, short cycle and more stable. IHC staining, including ER, PR, Ki-67, Her-2, CK5/6 and EGFR, can be used to classify breast cancer into different molecular subtypes and assist in the determination of treatment options. The application of artificial intelligence in pathological morphology is in the ascendant. Different algorithms can be used to evaluate both IHC staining and HE staining morphological evaluation of tumor tissues (including histological grading).In the molecular typing of breast cancer by IHC, the digital slide images obtained by scanning with software analysis can greatly reduce the subjectivity and instability of manual evaluation and improve the repeatability. Firstly, we scanned whole slide digital image of the HE staining slides and the six IHC slides of 200 surgical specimens of breast cancer with different molecular types (non-special types) from a medical center (Peking Union Medical College Hospital).Then compare the immunohistochemical results of each case obtained manually, adjust the algorithm, calibrate the parameters in the software, and finally get the fixed algorithm code and parameters. The algorithms used in study include image classification, nuclei segmentation, channel association and image registration. The algorithms were verified in the other surgical resection specimens of 400 cases of breast cancer with different molecular types (non-special types) from two other medical center, and was compared with the data obtained by manual reading. Finally, the results were encouraging, with the consistency of molecular classification reaching 100%. This study shows AI technology has great application prospect in pathological diagnosis of breast cancer.

Citation Format: Jean J. Zhao, Minzi Ruan, Quancai Cui. Artificial intelligence aided diagnosis of breast cancer molecular classification based on immunohistochemical images [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 LB-279.