bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1854: A Fc-competent anti-human TIGIT blocking antibody BGB-A1217 elicits strong immune responses and potent anti-tumor efficacy in pre-clinical models
Authors: Chen Xin , Xue Liu , Ding Xiao , Liu Qi , Zhang Jing , Jiang Lei , Liu Sha , Hou Hongjia , Zhu Qing , Jiang Bin , Zhang Lijie , Zhou Xiaosui , Ma Jie , Li Yucheng , Jin Wei , Wei Min , Shen Zhirong , Liu Mike , Li Kang , Zhang Tong 
Published: July 2021

Abstract
Background: TIGIT (T-cell immunoglobulin and ITIM domain) is a “checkpoint” inhibitory receptor, which is primarily expressed on activated and “exhausted” T and NK cells. Engagement of TIGIT to its ligands (i.e., PVR and PVR-L2) leads to inhibitory signaling in T cells, promoting functional exhaustion of tumor-infiltrating T lymphocytes. BGB-A1217 is a novel humanized IgG1 anti-TIGIT antibody under clinical development. The immunomodulatory activity of BGB-A1217 was evaluated both in vitro and in vivo.
Materials and methods: BGB-A1217 was generated through hybridoma fusion, humanized by CDR grafting and structural simulation. The binding affinity and specificity were studied by FACS and SPR. The immunomodulatory functions of BGB-A1217 were evaluated using primary immune cells as well as using animal models.
Results: BGB-A1217 binds to the extracellular domain of human TIGIT with high affinity (KD = 0.135 nM) and specificity. In a competition assay, BGB-A1217 efficiently blocks the interaction between TIGIT and PVR. In vitro, BGB-A1217 significantly enhances T-cell functions and induces potential ADCC against TIGITHi targets. In a human T-cell assay, BGB-A1217 enhances IFN-γ production of CMV-specific T cells. In a PBMC assay, BGB-A1217 augments T cell response, either alone or in combination with an anti-PD-1 antibody BGB-A317. Besides blocking TIGIT signaling, BGB-A1217 can also remove TIGIT from cell surface through trogocytosis. This activity is Fc-dependent. In vivo, the Fc effector function is critical for the activity of BGB-A1217 against CT26WT tumor implanted in humanized TIGIT knock-in mice. The observed anti-tumor efficacy is associated with pharmacodynamic change of TIGIT down-regulation, CD226 upregulation and Treg depletion at 48hrs after first dosing.
Conclusions: BGB-A1217, either alone or in combination with anti-PD-1 mAb promotes immune cell activation both in vitro and in vivo, supporting its clinical development for the treatment of human cancers.
Citation Format: Xin Chen, Liu Xue, Xiao Ding, Qi Liu, Jing Zhang, Lei Jiang, Sha Liu, Hongjia Hou, Qing Zhu, Bin Jiang, Lijie Zhang, Xiaosui Zhou, Jie Ma, Yucheng Li, Wei Jin, Min Wei, Zhirong Shen, Mike Liu, Kang Li, Tong Zhang. A Fc-competent anti-human TIGIT blocking antibody BGB-A1217 elicits strong immune responses and potent anti-tumor efficacy in pre-clinical models [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 1854.
Abstract 1856: Donor and antibody diversity in NK cell-mediated antibody dependent cellular cytotoxicity (ADCC) detected using an optimized multiplexed assay and advanced flow cytometry
Authors: Lovchik Julie , Carter Mark 
Published: July 2021

Abstract
Tumor-specific monoclonal antibodies (mAb) which induce NK cell-mediated antibody dependent cellular cytotoxicity (ADCC) have proven to be successful against several types of cancer. Evaluating the potency of a new, tumor-specific mAb requires testing with multiple sources of donor cells since the degree of NK cell-mediated ADCC is known to be variable between patients. Thus, in addition to evaluating whether a new tumor-specific mAb can effectively induce NK cell-mediated ADCC, it is also important to characterize the donor NK cells utilized in order to provide insight into potential treatment efficacy. In the current study, we investigated the application of a novel, high throughput assay in assessing the ADCC potency of different anti-hCD20 mAbs against a Burkitt's lymphoma cell line using effector cells obtained from multiple donors. This multiplexed assay incorporates a cells and beads format to enable the simultaneous measurement of target cell killing, along with enumeration and phenotyping of the NK cells, and quantification of up to 8 secreted effector proteins and cytokines. The assay requires a sample volume of just 10 µl and can be performed in a single well of a 96 or 384 well plate using the iQue® platform for advanced flow cytometry. Data analysis and visualization was done using the integrated iQue Forecyt® software package. The results showed a mAb concentration-dependent increase in tumor cell killing, along with corresponding increases in secretion of Granzyme B and CD178 (Fas Ligand), and production of IFNγ, TNF, and RANTES. The degree of NK cell-mediated ADCC and effector protein secretion levels were dependent on both the anti-hCD20 mAb and donor cells used, with higher levels of ADCC and effector protein secretion observed using a non-fucosylated anti-hCD20 mAb as compared to a conventional, fucosylated anti-hCD20 mAb. This method enabled the rapid assessment of the potency of different mAbs in ADCC mediated by NK cells, and also effectively distinguished potential differences in mAb efficacy between donors.
Citation Format: Julie Lovchik, Mark Carter. Donor and antibody diversity in NK cell-mediated antibody dependent cellular cytotoxicity (ADCC) detected using an optimized multiplexed assay and advanced flow cytometry [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 1856.
Abstract 1867: Characterization in patient derived tumor organoids of novel oncolytic adenoviruses expressing enhanced cross-hybrid IgGA Fc PD-L1 inhibitors
Authors: Hamdan Firas , Ylösmäki Erkko , Chiaro Jacopo , Giannoula Yvonne , Long Maeve , Fusciello Manlio , Feola Sara , Martins Beatriz , Feodoroff Michaela , Antignani Gabriella , Kari Otto , Lee Moon Hee , Järvinen Petrus , Nisen Harry , Kreutzman Anna , Mustjoki Satu , McWilliams Thomas G , Grönholm Mikaela , Cerullo Vincenzo 
Published: July 2021

Abstract
Despite the success of immune checkpoint inhibitors in the clinic, they only benefit a fraction of patients. A theoretical strategy to increase efficacy would be to enhance such antibodies with Fc-mediated effector mechanisms. Current IgG1 antibodies are excellent activators of natural killer cells yet neglect a crucial effector population, neutrophils. Hence, we designed a cross-hybrid Fc-fusion peptide against PD-L1 able to elicit simultaneously effector mechanisms of an IgG1 but also IgA1, consequently activating neutrophils, in order to combine multiple effector mechanisms. Moreover, to prevent toxicities, these Fc-fusion peptides were cloned in oncolytic adenoviruses whose replication is restricted to the tumor. Our oncolytic adenoviruses were able to selectively infect tumor cells, secrete the cross-hybrid Fc-fusion peptides able to bind to PD-L1 and activate multiple immune components enhancing tumor cytotoxicity compared to FDA-approved immune checkpoint inhibitors. We validated this in various human and murine cancer cell lines and also renal cell carcinoma patient derived organoids from four patients. In conclusion, our cross-hybrid Fc-fusion peptides demonstrate that activating multiple immune effector populations increases tumor cytotoxicity potentially leading to improved clinical outcomes.
Citation Format: Firas Hamdan, Erkko Ylösmäki, Jacopo Chiaro, Yvonne Giannoula, Maeve Long, Manlio Fusciello, Sara Feola, Beatriz Martins, Michaela Feodoroff, Gabriella Antignani, Otto Kari, Moon Hee Lee, Petrus Järvinen, Harry Nisen, Anna Kreutzman, Satu Mustjoki, Thomas G McWilliams, Mikaela Grönholm, Vincenzo Cerullo. Characterization in patient derived tumor organoids of novel oncolytic adenoviruses expressing enhanced cross-hybrid IgGA Fc PD-L1 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 1867.
Abstract 1868: A long acting bi-specific T cell engager differentially targeting CD47 positive malignant cells but not CD47 expressing healthy cells
Authors: Liu Shumin , Lyu Weidong , Lei Yang , Tan Shuangyu , Wu Zibin , Yin Shuqiang , Zheng Liling , Zhuo Qiudong , Wen Yu (Yvonne) , Wu David 
Published: July 2021

Abstract
Currently both bispecific T cell engagers (BiTE) and innate immune checkpoint blockades (eg. Anti-CD47/SIRPα) have been under development. In this study, we developed a novel compound pegylated anti-CD3 x anti-CD47 which could act with dual mechanisms of both a BiTE and an innate immune checkpoint blockade. The compound did not induce hemagglutination of RBC cells at the extremely high concentration of 2250 ug/ml, while the corresponding monoclonal antibody Hu5F9-G4 did at the concentration as low as 16.67 ug/ml. Meanwhile, in a T cell apoptosis assay, the apoptotic T cells were 16.13%, only 5.9% higher than that of the control T cell sample at the concentration of 100ug/ml of the compound and were about the same as the control sample (10.23%) at concentration of 10 ug/ml of the compound. For comparison, the reported T cell apoptosis induced by 10ug/ml Hu5F9-G4 was as high as 70%. Furthermore, the target affinity by flow cytometry demonstrated that at the concentration 10ug/ml of the compound, stained RBCs were 0.551%, while the compound bound BxPC3 cells were 22.1%, a 40-fold difference in binding. At the concentration 100ug/ml of the compound, only 7.24% RBCs were stained positively, but stained BxPC3 cells were as high as 89.3%. Although not completely understood yet, unique structure of the compound (PEGylated scFv antibody v.s. Fc-bearing antibodies) may have contributed to the differential effect of the compound to healthy cells and tumor cells, resulting in high safety performance of the compound. Furthermore, pharmacokinetics study demonstrated that in vivo elimination half-life of the compound in wild type C57BL/6 mice was 18.4 hours for the single dose of 1mg/kg. Further preclinical study about the compound is still ongoing.
Citation Format: Shumin Liu, Weidong Lyu, Yang Lei, Shuangyu Tan, Zibin Wu, Shuqiang Yin, Liling Zheng, Qiudong Zhuo, Yu (Yvonne) Wen, David Wu. A long acting bi-specific T cell engager differentially targeting CD47 positive malignant cells but not CD47 expressing healthy cells [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 1868.
Abstract 1872: Generation of bispecific and trispecific T cell engagers (TCEs) and NK cell engagers (NKE)s without prior IgG reengineering
Authors: van Geel Remon , van Delft Floris 
Published: July 2021

Abstract
T cell and NK cell-redirecting antibodies are emerging as promising modalities in targeted immunotherapy. New technologies are overcoming the limitations of 1st generation immune cell-redirecting bispecifics, especially extending half-life, reducing immunogenicity and improving safety. For example, in the field of T cell engagers (TCEs), a plethora of molecular architectures has entered the clinic, the vast majority generated by genetic engineering of an IgG to bind both a tumor-associated antigen (TAA) and CD3 or 4-1BB. Similarly, recombinant DNA technology enables the C-terminal fusion of a cytokine (e.g. IL-2 or IL-15) to an IgG to obtain NK cell engagers (NKEs).
We have shown earlier that the native glycan of a monoclonal antibody provides a privileged site for attachment of cytotoxic payloads,1 providing antibody-drug conjugates (ADCs) with significantly enhanced therapeutic index. This technology, known as GlycoConnect™, has been adapted by various drug developers (e.g. ADC Therapeutics, Mersana Therapeutics and others) and is now applied in two (2) clinical programs as well as multiple late-stage preclinical programs.
Here we demonstrate how GlycoConnect™ technology can be applied to generate TCEs or NKEs by selective attachment of scFv (anti-CD3, anti-CD28) or cytokines (IL-15), with concomitant Fc-silencing. Moreover, an existing bispecific TCE (TAA/CD3) can be further boosted by attachment of anti-CD28 scFv for further T cell activation. Molecular architectures can be readily tailored to 2:2 or 2:1 ratio (TAA:scFv or cytokine) to mitigate adverse events like cytokine release syndrome, and even 2:1:1 formats. Structural and functional studies will be presented to corroborate the architecture and biological activity of these GlycoConnect™ bispecifics and trispecifics, in terms of binding, immune cell engagement and cell-killing potential.
1van Geel et al. Chemoenzymatic Conjugation of Toxic Payloads to the Globally Conserved N-Glycan of Native mAbs Provides Homogeneous and Highly Efficacious Antibody−Drug Conjugates. Bioconj. Chem. 2015, 26, 2233-2242.
Citation Format: Remon van Geel, Floris van Delft. Generation of bispecific and trispecific T cell engagers (TCEs) and NK cell engagers (NKE)s without prior IgG reengineering [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 1872.
Abstract 1879: CIT-801: a bifunctional anti-PD1xIL15 agent demonstrated synergy and enhanced in vivo anti-tumor efficacy
Authors: Li Yiwen , Hu Yuxiang , Wang Welson , Wu Wei 
Published: July 2021

Abstract
PD1/PD-L1 antibody has revolutionized cancer therapy. However, only a subset of cancer patients are responsive to anti-PD1 antibody treatment. Lack of immune effector cells in the tumor microenvironment (cold tumor) is considered a major reason for such a resistance. Interleukin 15 (IL15) is a cytokine critical for the survival and proliferation of T-cells and NK cells. We hypothesized that a combination of IL15 with anti-PD1 antibody might turn a cold tumor into a hot tumor and overcome tumor resistance to PD1 therapy, and therefore benefit a larger cancer patient population. We have constructed a homodimeric bifunctional agent (CIT-801) that is composed of an anti-PD1 antibody (CIT-100) and IL15 plus the sushi domain of IL15Rα. In vitro, this bifunctional anti-PD1xIL15 agent retained the ability of its anti-PD1 component to enhance T-cell activation in both mixed leukocyte reaction (MLR) and PD1 luciferase reporter assays. It also retained the ability of its IL15 component to stimulate the proliferation of T-cells. Moreover, the bifunctional agent was able to enhance the activation, proliferation and cytotoxicity of NK cells in vitro. In a syngeneic MC38 tumor model with human-PD1 knock-in mice, the bifunctional anti-PD1xIL15 agent strongly inhibited tumor growth, superior to anti-PD1 antibody treatment alone. In summary, anti-PD1xIL15 bifunctional compound CIT-801 has shown a great therapeutic potential and is worth further development.
Citation Format: Yiwen Li, Yuxiang Hu, Welson Wang, Wei Wu. CIT-801: a bifunctional anti-PD1xIL15 agent demonstrated synergy and enhanced in vivo anti-tumor efficacy [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 1879.
Abstract 1885: Potent tumoricidal activity of a FGFR4 CART in rhabdomyosarcoma
Authors: Cheuk Adam , Tian Meijie , Kumar Jeetendra , Azorsa Peter , Shivaprasad Nityashree , Schneider Dina , Gryder Berkley , Wei Jun , Song Young , Wen Xinyu , Sindiri Sivasish , Chung Joon-Yong , Zhu Zhongyu , Dimitrov Dimiter , Hewitt Stephen , Dropulic Boro , Orentas Rimas , Khan Javed 
Published: July 2021

Abstract
Despite decades of multi-module therapies, RMS remains incurable once it has metastasized, thus new therapeutic strategies are warranted. FGFR4 is a developmentally regulated cell surface receptor tyrosine kinase, overexpressed in virtually all, mutationally activated in about 10% of RMS, and directly activated by PAX3-FOXO1 fusion protein which makes it a tractable target for immunotherapy. We generated fifteen binders against FGFR4 and characterized them further as candidate molecules for immune therapy. We found that 3A11, a mouse IgG antibody, bound to FGFR4 positive cell lines. The VL and VH domain of 3A11 was cloned and made into scFvFc format (mouse Fv and Human IgG1 Fc). The chimeric form of 3A11 antibody was successfully produced in vitro and retained its FGFR4 specificity with an observed binding affinity at nanomolar range. By ELISA using the extra cellular domain of human FGFR1, FGFR2, FGFR3 or FGFR4, 3A11 scFvFc showed dose dependent binding to FGFR4 only. We then made 3A11 into a second generation CAR. Human T cells transduced with 3A11 CAR construct were found to be highly potent at inducing IFN-γ, TNF-α, IL-2 and cytotoxicity when the FGFR4-CART was co-cultured with RMS cells, but not with RMS cells with FGFR4 knocked out and FGFR4 negative cells. Our in vivo testing also found that 3A11 CART was able to eliminate RMS cells in murine xenograft metastatic models. Here we report the successful generation of binders specific to human FGFR4. FGFR4 CAR developed from 3A11 was able to kill FGFR4 positive target cells both in-vivo and in-vitro. Thus, 3A11 CAR T cells targeting FGFR4 may provide effective immune therapies for rhabdomyosarcoma and other FGFR4 expressing cancers and clinical trials are planned.
Citation Format: Adam Cheuk, Meijie Tian, Jeetendra Kumar, Peter Azorsa, Nityashree Shivaprasad, Dina Schneider, Berkley Gryder, Jun Wei, Young Song, Xinyu Wen, Sivasish Sindiri, Joon-Yong Chung, Zhongyu Zhu, Dimiter Dimitrov, Stephen Hewitt, Boro Dropulic, Rimas Orentas, Javed Khan. Potent tumoricidal activity of a FGFR4 CART in rhabdomyosarcoma [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 1885.
Abstract 1887: Anti-CD38/CD28xCD3 trispecific T cell engager induces proliferation of primary T cells and mediates potent killing of primary malignant plasma cells isolated from Multiple Myeloma bone marrow aspirates
Authors: El-Murr Nizar , Kassem Sahar , Carrié Nadège , Henry Christophe , Virone-Oddos Angela , Yang Zhi-yong , Wiederschain Dmitri , de Velde Helgi Van , Chiron Marielle , Martinet Ludovic 
Published: July 2021

Abstract
Despite recent breakthrough in the treatment of multiple myeloma (MM) relapses are frequent, highlighting the need for novel approaches. Here we describe a novel anti-CD38/CD28xCD3 trispecific T cell engager (TCE) that targets CD38 expressed by malignant plasma cells and activates T cells by engaging CD3 and CD28 (1). Using bone marrow (BM) aspirates from MM patients, we confirmed that binding to malignant plasmocytes is primarily driven by the expression of CD38 and showed ex vivo that CD38/CD28xCD3 TCE induces a dose-dependent proliferation of CD4+ and CD8+ effector T cells. We also showed that MM patients' primary T cells were stimulated by CD38/CD28xCD3 TCE resulting in RPMI 8226 MM cell line lysis in co-culture assays. Killing of tumor cells was accompanied by MM effector CD8+ T cell degranulation and immunostimulatory cytokine production (IFN-γ and TNF-α). Finally, using MM patients' total BM cells, we showed that CD38/CD28xCD3 TCE induced the activation and cytokine production by cytotoxic CD8+ T cells and the CD38-dependent depletion of autologous primary malignant plasmocytes. Importantly, treatment of total BM cells with CD38/CD28xCD3 TCE also led to a CD38-dependent depletion of immunosuppressive myeloid derived suppressor cells (MDSC) that express CD38. Overall, these data show that CD38/CD28xCD3 trispecific TCE is active against primary myeloma cells and support the current evaluation of this next generation anti-CD38 multi-specific antibody in phase I clinical trial in patients with relapsed/refractory MM.
(1) Wu, L., Seung, E., Xu, L. et al. Trispecific antibodies enhance the therapeutic efficacy of tumor-directed T cells through T cell receptor co-stimulation. Nat Cancer 1, 86-98 (2020).
Citation Format: Nizar El-Murr, Sahar Kassem, Nadège Carrié, Christophe Henry, Angela Virone-Oddos, Zhi-yong Yang, Dmitri Wiederschain, Helgi Van de Velde, Marielle Chiron, Ludovic Martinet. Anti-CD38/CD28xCD3 trispecific T cell engager induces proliferation of primary T cells and mediates potent killing of primary malignant plasma cells isolated from Multiple Myeloma bone marrow aspirates [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 1887.
Abstract 1892: Proteomic interrogation of the metabolic control of MHC class I antigen presentation in metastatic melanoma
Authors: McKinnon Alyson , Avaritt Nathan , Tackett Alan , Koss Brian 
Published: July 2021

Abstract
Since 2014, immune checkpoint inhibitors (ICIs) have led the charge against metastatic melanoma as the most commonly utilized first-line treatment. While ICIs have dramatically increased the 5-year overall survival rate, only half of patients respond to treatment. Recently, a proteomic study correlated high levels of tumor mitochondrial metabolic proteins and MHC-related proteins to responsiveness to anti-PD-1 and anti-CTLA-4 immune checkpoint inhibitor treatment. In a study of 91 melanoma cell lines in the European Searchable Tumor Cell and Databank, 67% of the cell lines exhibited HLA class antigen alterations, most commonly being down-regulation of HLA-B. Loss of MHC expression is a mechanism proposed to aid in evading the immune system by decreasing T-cell recognition and killing. Approaches to reverse tumor MHC loss is needed as it is a known mechanism utilized by melanoma and increased MHC expression has been linked to ICI responders. The connection between metabolism and MHC correlation has not been fully explored, and this study sought to further explore that relationship through a proteomic analysis of a metabolically conditioned B16F10 murine melanoma model. To expand our understanding of the metabolic control of MHC Class I antigen presentation, we cultured B16F10 melanoma cells in galactose media (B16.Gal), forcing the cells into an oxidative phosphorylative state relative to B16F10 melanoma cells cultured in glucose media (B16.Glu) which exhibit a glycolytic metabolic profile. We show that enforcing mitochondrial respiration restores the lost basal MHC expression and enhances the response to interferon gamma. Further, B16.Gal cells show higher rates of T-cell killing and increased PD-L1 expression. This phenotype proved reversible as shown by moving B16.Gal cells back into glucose media (B16.GalGlu), supporting the formation of a metabolically conditioned cell model rather than a favorable selection of compatible cells. We used proteomics to identify the driving forces behind the restoration of MHC expression. The identification of these forces could provide novel therapeutic targets for enhancing immunotherapy of melanoma.
Citation Format: Alyson McKinnon, Nathan Avaritt, Alan Tackett, Brian Koss. Proteomic interrogation of the metabolic control of MHC class I antigen presentation in metastatic melanoma [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 1892.