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  • 1
    In: Cell Death & Disease, Springer Science and Business Media LLC, Vol. 9, No. 5 ( 2018-04-18)
    Abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has raised attention as a novel anticancer therapeutic as it induces apoptosis preferentially in tumor cells. However, first-generation TRAIL-receptor agonists (TRAs), comprising recombinant TRAIL and agonistic receptor-specific antibodies, have not demonstrated anticancer activity in clinical studies. In fact, cancer cells are often resistant to conventional TRAs. Therefore, in addition to TRAIL-sensitizing strategies, next-generation TRAs with superior apoptotic activity are warranted. APG350 is a novel, highly potent TRAIL-receptor agonist with a hexavalent binding mode allowing the clustering of six TRAIL-receptors per drug molecule. Here we report on preclinical in vitro and in vivo studies testing the activity of APG350 on pancreatic ductal adenocarcinoma (PDAC) cells. We found that APG350 potently induced apoptosis of Colo357, PancTuI and Panc89 cells in vitro. In addition, APG350 treatment activated non-canonical TRAIL signaling pathways (MAPK, p38, JNK, ERK1/ERK2 and NF-κB) and induced the secretion of IL-8. Stable overexpression of Bcl-xL inhibited APG350-induced cell death and augmented activation of non-canonical pathways. Intriguingly, pre-treatment of Bcl-xL-overexpressing cells with the BH3-mimic Navitoclax restored their sensitivity to APG350. To study the effects of APG350 on PDAC cells in vivo, we applied two different orthotopic xenotransplantation mouse models, with and without primary tumor resection, representing adjuvant and palliative treatment regimes, respectively. APG350 treatment of established tumors (palliative treatment) significantly reduced tumor burden. These effects, however, were not seen in tumors with enforced overexpression of Bcl-xL. Upon primary tumor resection and subsequent APG350 treatment (adjuvant therapy), APG350 limited recurrent tumor growth and metastases. Importantly, therapeutic efficacy of APG350 treatment was more effective compared with treatment with soluble TRAIL in both models. In conclusion, APG350 represents a promising next-generation TRA for the treatment of PDAC. Moreover, our results suggest that combining APG350 with Navitoclax might be a succesfull strategy for cancers harboring mitochondrial apoptosis resistance.
    Type of Medium: Online Resource
    ISSN: 2041-4889
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2018
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  • 2
    In: Frontiers in Oncology, Frontiers Media SA, Vol. 8 ( 2018-9-19)
    Type of Medium: Online Resource
    ISSN: 2234-943X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2018
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  • 3
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 79, No. 13_Supplement ( 2019-07-01), p. 4143-4143
    Abstract: Glucocorticoid-induced TNFR-related protein (GITR, TNFRSF18, CD357), a TNFR-SF member, is a co-stimulatory receptor that increases anti-tumor T cell activation. Based on Apogenix TNFR-SF agonist HERA-technology, we created a fully human hexavalent GITR ligand fusion protein - HERA-GITRL - intended for T cell costimulatory approaches in immuno-oncology (IO) therapy. HERA-GITRL is composed of a trivalent single chain GITRL-receptor-binding-domain fused to an IgG1-derived silenced Fc-domain serving as dimerization scaffold. The unique design that combines a molecular mimic of the endogenous GITRL with a silenced Fc-domain, allows the study of pure GITR agonism in contrast to Fc-mediated mixed modes of action. Here we report in vitro and in vivo properties of our novel HERA-GITRL construct. For functional characterization of HERA-GITRL in vitro, human immune cells isolated from healthy-donor blood were profiled by multicolor flow cytometry and real-time cell analysis. Stimulation of unfractionated human T cells or purified naïve CD4+ T cells by anti-CD3 antibody was further augmented by HERA-GITRL. This effect was accompanied by increased proliferation, differentiation and elevated levels of TNF-α and IFN-γ. Importantly, HERA-GITRL-mediated T cell activation increases tumor cell killing by PBMCs in vitro and showed in vivo anti-tumor efficacy as a single agent in a subcutaneous syngeneic colon cancer model (CT26wt) in mice. This anti-tumor effect is independent of its Fc functionality, as murine HERA-GITR ligands with functional Fc- or silenced Fc-domains show similar tumor growth inhibition. TRX518, an anti-human GITR monoclonal antibody currently investigated in a clinical Phase I study, was used in a direct in vitro comparison with trivalent GITRL and our hexavalent HERA-GITRL. Without crosslinking HERA-GITRL showed superior agonistic activity over trivalent GITRL and TRX518. Crosslinking increased the activity of trivalent GITRL while the residual activity of TRX518 was even decreased. We constructed a CHO cell line stably expressing fully human HERA-GITRL with high purity and yield. The resulting research cell bank is ready to be used for subsequent GMP process development. By clustering the receptor chains in a spatially well-defined manner, HERA-GITRL induces potent agonistic activity without being dependent on additional Fc-mediated crosslinking. A comparison of HERA-GITRL with the anti-GITR antibody TRX518 showed superior agonistic activity of our HERA construct in vitro with and without cross-linking. The HERA-ligand concept has also been successfully translated to HERA-TRAIL (now in Phase I), -CD40L, -CD27L,-LIGHT and -4-1BBL. Citation Format: Matthias Schröder, Viola Marshall, Meinolf Thiemann, David M. Richards, Christian Merz, Jaromir Sykora, Julian P. Sefrin, Mauricio Redondo-Müller, Karl Heinonen, Katharina Billian-Frey, Oliver Hill, Christian Gieffers. The novel hexavalent human GITR agonist HERA-GITRL promotes anti-tumor efficacy independent of Fc-functionality and shows superior activity compared with the monoclonal anti-GITR antibody TRX518 [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 4143.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2019
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  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 14_Supplement ( 2016-07-15), p. 1204-1204
    Abstract: Tumor necrosis factor receptor superfamily (TNFRSF) proteins are widely expressed by immune and tumor cells. Their importance in many locations and phases of the anti-tumor immune response is now broadly appreciated and several TNFR agonists are currently in preclinical and clinical development. Importantly, signaling through many TNFRSF members, such as CD40, CD27, OX40, 4-1BB, HVEM and GITR, is potentially associated with an enhanced anti tumor response via co-stimulation of immune cells. Apogenix has established a development platform for a novel class of TNFRSF-agonists for the treatment of cancer. Unlike their natural homotrimeric counterparts, the Apogenix recombinant TNFSF proteins consist of one single polypeptide chain composed of three receptor-binding domain-forming protomers. These single-chain TNFSF receptor-binding domains (scTNFSF-RBD) are mimics of the three-dimensional organization of the natural TNFSF-cytokine and can be used to engineer fully human fusion-proteins from a modular toolbox. For example, fusing an IgG1 Fc-domain to the C-terminus of a scTNFSF-RBD creates a hexavalent agonist as the Fc-domain acts as a dimerization scaffold for two trivalent scTNFSF-RBDs. As a result of this molecular design, each drug molecule is capable of clustering six receptors in a spatially well-defined manner. Consequently, TNFSF receptor signaling following treatment with the Apogenix scTNFSF-RBD-Fc in vivo is independent of secondary clustering through Fc-γ receptors that is required for many anti-TNFRSF agonistic antibodies (e.g., anti-TRAILR2 or -CD40). Following up the scTRAIL-RBD-Fc prototype, this engineering concept has now been successfully translated to CD40L and CD27L resulting in hexavalent agonists suitable for further development. Expression of the drug candidates in CHO suspension cells followed by an AFC and SEC-based lab-scale purification process resulted in homogenous aggregate-free protein lots. The purified proteins bind their respective target-receptors with high affinity. In vivo stability/PK studies have been performed in addition to in vitro experiments with primary human and mouse lymphoid and myeloid cell populations. Specifically, it was shown that scCD27L-RBD-Fc was able to bind CD27 expressed on primary human CD4+ and CD8+ T cells. Importantly, binding significantly increased T cell expansion following activation. Treatment with scCD40L-RBD-Fc induced differentiation of B cells and enhanced primary human monocyte differentiation into DCs or M1 macrophages. Encouraged by the promising results obtained with TRAIL, CD40L, and CD27L, Apogenix is currently expanding the TNFRSF-agonist pipeline to target additional cell populations, locations and phases of the immune response in order to develop novel therapies to treat cancer and other conditions. Citation Format: Christian Merz, Christian Gieffers, Michael Kluge, David M. Richards, Tim Schnyder, Jaromir Sykora, Meinolf Thiemann, Harald Fricke, Oliver Hill. A construction platform for hexavalent agonists targeting receptors of the tumor necrosis factor superfamily: Where death meets co-stimulation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1204.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2016
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  • 5
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 14_Supplement ( 2016-07-15), p. 464-464
    Abstract: CD95 (APO-1/Fas) is a member of the Tumor Necrosis Factor Receptor Super Family. Binding of CD95-ligand (CD95L) to CD95 triggers intracellular signal transduction that is critically involved in the invasive growth of glioblastoma cells. Invasion of malignant glioblastoma cells into the brain parenchyma is responsible for poor therapeutic outcome of currently available treatments. The inhibition of CD95/CD95L mediated invasive growth of glioblastoma cells represents an attractive novel therapeutic concept. Apogenix has developed APG101, a fully human fusion protein consisting of the extracellular domain of CD95 and the Fc-domain of an IgG. APG101 has been confirmed as a potent inhibitor of CD95L induced invasion of glioblastoma cells in vitro. In a randomized phase 2 study in glioblastoma patients with 1st or 2nd relapse the combined therapy of APG101 plus radiotherapy (RT) was found to be superior to RT alone in a clinically relevant order of magnitude in all efficacy endpoints (i.e. PFS-6, PFS and OS). At the same time APG101 exhibited an excellent safety profile and was well tolerated. To identify potential biomarkers we used available tissue sections originating from archived primary tumor of the study patients and analyzed them for the expression of CD95L as well as for the DNA methylation status. A genome-wide assessment of DNA methylation identified a single CpG-site (CpG2) upstream of the CD95L-promotor that showed differential methylation between APG101 responders (PFS & gt;5 months) and non-responders (PFS & lt; 2 months). Available patient DNAs were in addition analyzed by MassARRAY and Pyro-sequencing to confirm differential CpG2 methylation. Based on this data we used the median of the CpG2 methylation level as a threshold to analyze for a correlation of CpG2 methylation and response to APG101 therapy. Patients showing a low level of CpG2 methylation responded best to therapy with APG101 whereas patients with a high level of CpG2 methylation did not show a relevant benefit when treated with APG101 compared to the control RT-group. The analysis shows a significant survival benefit achieved in patients with low CpG2 methylation (median OS: 16.1 vs 7.3 months, p = 0.029). Hence, the level of CpG2 methylation in the CD95L promoter in the patients' glioblastoma tissue is a prognostic biomarker predicting response to therapy with APG101. Based on the observations described, Apogenix currently develops a qPCR-based assay to quantify CpG2 methylation. This assay is intended as companion diagnostic to identify patients that may respond best to APG101 treatment. Citation Format: Christian Gieffers, Claudia Kunz, Jaromir Sykora, Christian Merz, Meinolf Thiemann, Harald Fricke, Benedikt Wiestler, Wolfgang Wick. Methylation of a single CpG site in the CD95-ligand promoter is a biomarker predicting the response to therapy with APG101 in glioblastoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 464.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2016
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  • 6
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 1760-1760
    Abstract: Introduction: HERA-CD40L is a novel hexavalent CD40 agonist engineered with the HERA-Technology developed by Apogenix. We have previously shown that the natural binding mode via the receptor/ligand binding domains and the high clustering capacity for the cognate receptor clearly distinguish HERA-CD40L from other, e.g. antibody-based, CD40-targeting compounds. Here, we report on the effects of HERA-CD40L on crosstalk between T cells and antigen presenting cells (APC) and the functional consequences in vitro. Materials & Methods: Biological activity of CD40 agonists was analyzed using co-cultures of primary T cells with B cells or monocytes/macrophages. All primary cells were isolated by negative selection using magnetic sorting from healthy donor buffy coats. Expression of CD markers upon CD40 ligation on B cells and monocytes was analyzed by flow cytometry (FC). Monitoring of T cell-induced killing of tumor cells primed in direct co-cultures with APC was done on a real-time cell analysis system (xCELLigence). For analysis of phagocytosis, we developed an FC-based assay employing primary monocytes/macrophages and Jurkat A3 cells. Results: Treatment of primary B cells and monocytes with HERA-CD40L induced expression of co-stimulatory molecules, like CD86, and promotes M1 maturation of naïve (M0) monocytes. In vitro, treatment of alternatively activated M2 macrophages with HERA-CD40L induced an M2 to M1 phenotype switch (re-programming) which concurs with CD16 downregulation and a dose-dependent decrease of phagocytic activity of re-programmed macrophages compared to M0 or M2 macrophages. Primary B cells and M1 macrophages enhanced the proliferation and cytotoxic activity of naïve T cells in direct co-cultures in the presence of HERA-CD40L. The activating effect on T cells required direct cell-cell contact with APC and was not observed in indirect co-cultures. Functionally, neutralization of either MHC-I or CD80/CD86 in direct co-cultures inhibited full activation of the T cells in vitro as shown by kill assays with various tumor cell lines. Conclusion: The hexavalent CD40 agonist HERA-CD40L produced by the Apogenix HERA-Technology is a potent immune-regulator acting on B cells and myeloid cells. HERA-CD40L promotes activation of B cells, maturation of APC and induces an M2 to M1 phenotype switch which inhibits tolerance-inducing phagocytic activity of the repolarized macrophages in vitro. In response to CD40 ligation on APC, an efficient anti-tumor response is conferred to primary T cells through cell-cell interactions via MHC-I and CD80/CD86. Citation Format: Christian Merz, Jaromir Sykora, Viola Marschall, David M. Richards, Meinolf Thiemann, Harald Fricke, Oliver Hill, Christian Gieffers. The hexavalent CD40 agonist HERA-CD40L augments multi-level crosstalk between T cells and antigen-presenting cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1760.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
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  • 7
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    Online Resource
    American Association for Cancer Research (AACR) ; 2020
    In:  Cancer Research Vol. 80, No. 16_Supplement ( 2020-08-15), p. 4529-4529
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 16_Supplement ( 2020-08-15), p. 4529-4529
    Abstract: The CD95 ligand (CD95L) is frequently overexpressed in cancers and tumor-associated endothelia, but also other immune cells like MDSCs and Tregs. Binding of CD95L expressed on tumors or regulatory immune cells to activated CD95-expressing effector cells triggers activation-induced apoptosis (AICD) or impairs their proliferation. In contrast, most tumors do also express CD95, but are intrinsically resistant to CD95-induced apoptosis. Thus, CD95L in the tumor microenvironment greatly contributes to the observed immunosuppression and escape from tumor surveillance by the immune system, making CD95 a potential immune checkpoint. Asunercept (APG101) is a fully human fusion protein consisting of the extracellular domain of CD95 and the Fc-domain of human IgG1, which efficiently inhibits CD95/CD95L signaling. Clinical efficacy has been demonstrated in a controlled randomized phase 2 study in patients with recurrent glioblastoma. Here we examined the effects of APG101 on innate and adaptive immune cells and subsequent effects on tumor cell killing. Subtypes of in vitro differentiated macrophages generated with and without exposure to APG101 were functionally and phenotypically analyzed by ELISA and multi-color flow cytometry following various stimuli. APG101 did not alter differentiation patterns and response of M1- and M2-like macrophages in vitro. Direct co-culture of monocytes with tumor cells resulted in an M2/TAM-like phenotype which was not influenced by APG101, but re-programming to an M1-like state was achieved by addition of a CD40 agonist. Effects of APG101 on the proliferation and activation of CD8+ T cells in the presence of autologous CD4+ T(reg) cells and allogeneic APC was assessed by CFSE-dilution and multi-color flow cytometry, respectively. The proliferation rate of CD8 T cells in co-cultures with CD4 T(reg) cells in response to stimulation with APCs was increased in the presence of APG101. Real-time cell analysis was performed employing direct co-cultures of activated T cells and tumor cell lines. Tumor killing assays using direct co-cultures of in vitro activated T cells with and without APG101 demonstrate that tumor killing was not impaired by APG101. Conclusion: Asunercept (APG101) is a potent inhibitor of pro-apoptotic/anti-proliferative CD95/CD95L signaling in immune cells and protects activated immune cells from activation induced cell death (AICD). Our results suggest that APG101 does not impair CD8 T cell activation, but rather supports their proliferation by disrupting CD95/CD95L interaction with regulatory T cells. Importantly, the primary anti-tumor killing mechanisms is most likely CD95L-independent and remains unaffected by the presence of APG101. The inhibition of CD95 signaling as an immune checkpoint represents an attractive and novel concept for immunologic treatment of tumors and the combination of Asunercept/APG101 with co-stimulatory TNFR-SF agonists is currently being investigated. Citation Format: Christian Merz, Jaromir Sykora, Rebecca Hussong, Meinolf Thiemann, Oliver Hill, Christian Gieffers. Neutralization of pro-apoptotic CD95L by Asunercept/APG101 does not impair anti-tumor immune responses [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4529.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 8
    In: Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 12, No. 12 ( 2013-12-01), p. 2735-2747
    Abstract: Cancer cells can be specifically driven into apoptosis by activating Death-receptor-4 (DR4; TRAIL-R1) and/or Death-receptor-5 (DR5; TRAIL-R2). Albeit showing promising preclinical efficacy, first-generation protein therapeutics addressing this pathway, especially agonistic anti-DR4/DR5-monoclonal antibodies, have not been clinically successful to date. Due to their bivalent binding mode, effective apoptosis induction by agonistic TRAIL-R antibodies is achieved only upon additional events leading to antibody-multimer formation. The binding of these multimers to their target subsequently leads to effective receptor-clustering on cancer cells. The research results presented here report on a new class of TRAIL-receptor agonists overcoming this intrinsic limitation observed for antibodies in general. The main feature of these agonists is a TRAIL-mimic consisting of three TRAIL-protomer subsequences combined in one polypeptide chain, termed the single-chain TRAIL-receptor–binding domain (scTRAIL-RBD). In the active compounds, two scTRAIL-RBDs with three receptor binding sites each are brought molecularly in close proximity resulting in a fusion protein with a hexavalent binding mode. In the case of APG350—the prototype of this engineering concept—this is achieved by fusing the Fc-part of a human immunoglobulin G1 (IgG1)-mutein C-terminally to the scTRAIL–RBD polypeptide, thereby creating six receptor binding sites per drug molecule. In vitro, APG350 is a potent inducer of apoptosis on human tumor cell lines and primary tumor cells. In vivo, treatment of mice bearing Colo205-xenograft tumors with APG350 showed a dose-dependent antitumor efficacy. By dedicated muteins, we confirmed that the observed in vivo efficacy of the hexavalent scTRAIL–RBD fusion proteins is—in contrast to agonistic antibodies—independent of FcγR-based cross-linking events. Mol Cancer Ther; 12(12); 2735–47. ©2013 AACR.
    Type of Medium: Online Resource
    ISSN: 1535-7163 , 1538-8514
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2013
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  • 9
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 72, No. 8_Supplement ( 2012-04-15), p. 3856-3856
    Abstract: APG350 is a TRAIL-receptor (TRAIL-R) agonist comprising two single-chain TRAIL-R binding domains (scTRAIL-RBD) that are dimerized via the Fc-part of a human IgG1-mutein thereby creating six receptor binding sites per molecule. This improved ability to form clusters on target cells composed of six TRAIL-Rs each, distinguishes APG350 from current clinical development candidates. In vitro, comparison of APG350 with recombinant APO2L/TRAIL and a TRAIL-R2 specific agonistic antibody revealed superior apoptosis induction for APG350 on primary and established human tumor cell-lines. Treatment of mice bearing Colo205 xenograft tumors with APG350, APO2L/TRAIL or an agonistic TRAIL-R2 specific antibody showed superior anti-tumor efficacy for APG350. Pronounced anti tumor efficacy was also shown on colon cancer stem cell (CSC) derived xenografts and successful APG350 re-treatment of relapsed CSC derived tumors demonstrated that tumors did not develop drug resistance. For most agonistic TRAIL-R antibodies effective apoptosis induction is achieved only upon additional cross-linking. SEC-based fractionation of a TRAIL-R2 specific agonistic antibody indicates a small amount of multimerized antibody that showed efficient apoptosis induction in vitro. However, the respective monomeric antibody showed poor apoptosis induction in vitro that could be enhanced upon cross-linking. In contrast apoptosis induction by APG350 was only marginally enhanced by cross-linking. Although monomeric agonistic TRAIL-R antibodies are poor apoptosis inducers in vitro, they show efficient apoptosis induction on xenograft tumors in vivo. A likely explanation for this difference is given by a recent publication showing that anti-tumor efficacy of an agonistic TRAIL-R2 specific antibody (Drozitumab) depends on cross-linking by Fcα-receptors (FcαR) in vivo. These data suggest that FcαR cross-linking might be a common requirement for the anti-tumor efficacy of agonistic TRAIL-R antibodies. To exclude that in vivo efficacy of APG350 depends on cross-linking by FcαRs we designed APG350-muteins with strongly reduced (APG808) or lacking FcαR binding (APG780). Side by side comparison of APG808, APG780 and APG350 in mice bearing Colo205-derived xenograft tumors showed identical anti-tumor efficacy for all respective proteins. Given that APG780 cannot bind to FcαRs these results suggest that the anti-tumor efficacy of APG808, APG780 and APG350 is solely based on the unique construction principle of the dimerized scTRAIL-RBD. APG350 induces superior clustering of TRAIL-Rs that in contrast to agonistic TRAIL-R antibodies does not require cross-linking via FcαRs for its potent anti-tumor efficacy. APG350 based dimerized scTRAIL-RBD formats may therefore have the capacity to bridge the current gap seen between preclinical and clinical efficacy for agonistic TRAIL-R specific antibodies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3856. doi:1538-7445.AM2012-3856
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2012
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  • 10
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    American Association for Cancer Research (AACR) ; 2017
    In:  Cancer Research Vol. 77, No. 13_Supplement ( 2017-07-01), p. 1688-1688
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 77, No. 13_Supplement ( 2017-07-01), p. 1688-1688
    Abstract: Introduction: Targeted therapeutics for cancer treatment are mostly developed as antibodies, however, the natural signaling complexes of the members of the TNF superfamily and their receptors consist of clusters of trimers. Consequently, most of these bivalent agonistic antibodies depend on Fc receptor mediated crosslinking for biological activity. The HERA-Technology developed by Apogenix generates hexavalent fusion proteins targeting the TNF-receptor superfamily with high clustering capacity for the cognate receptor, which overcomes this disadvantage of antibody-based drugs. Here we compared the efficacy of different CD40 agonist formats, including the novel HERA-CD40L and the functional consequences of differential receptor clustering. Materials & Methods: Biological activity of CD40 agonists was compared using an engineered reporter cell line and by flow cytometric analysis of CD40-induced IκBα degradation in Ramos B cells. T lymphocytes and monocytes were isolated from buffy coats and expression of CD markers upon CD40 ligation was analysed by multicolor flow cytometry (MC-FC). Secretion of cytokines in response to CD40 ligation was determined by ELISA. Monitoring of T cell-induced killing of tumor cells in direct co-cultures employed a real-time cell analysis system (xCELLigence). Results: Direct comparison of bivalent CD40 antibodies with trivalent CD40L and the hexavalent HERA-CD40L in two independent bioactivity assay formats demonstrated that only the hexavalent agonist was fully active without additional crosslinking. In contrast to HERA-CD40L, neither the bivalent agonistic CD40 antibody nor the trivalent CD40L were able to upregulate expression of activation markers on B cells or to induce secretion of proinflammatory cytokines such as IL-12 and TNFα by PBMCs. In vitro generated M2-macrophages acquired an M1 phenotype and enhanced proliferation of naïve CD4+ T cells in direct co-culture. Similarly, direct co-culture of CD4+ T cells with Ramos B cells in the presence of HERA-CD40L induced cytotoxic activity of CD4+ cells against tumor cells. The activating effect was dependent on cell-cell contacts and was not observed in indirect co-cultures. Importantly, only the hexavalent HERA-CD40L showed full biological activity without additional crosslinking. Conclusion: The hexavalent CD40 agonist HERA-CD40L produced by Apogenix HERA-Technology platform triggers CD40 signaling on B cells and cells of the monocytic lineage, leads to direct cytolytic activation and proliferation of CD4+ T cells and shifts the M1/M2 balance towards proinflammatory conditions. Unlike bivalent CD40 antibodies or trivalent CD40L_ based agonists, the hexavalent HERA-CD40L forms highly clustered signaling complexes and thus exhibits superior biological activity over other agonistic formats without the need for Fc receptor mediated crosslinking. Citation Format: Christian Merz, Jaromir Sykora, Meinolf Thiemann, Viola Marschall, Karl H. Heinonen, Harald Fricke, Christian Gieffers, Oliver Hill. HERA-CD40L: A novel hexavalent CD40 agonist with superior biological activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1688. doi:10.1158/1538-7445.AM2017-1688
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2017
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