Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Database
Language
Publication year range
1.
J Exp Med ; 215(3): 859-876, 2018 03 05.
Article in English | MEDLINE | ID: mdl-29436396

ABSTRACT

Depletion of immunosuppressive tumor-associated macrophages (TAMs) or reprogramming toward a proinflammatory activation state represent different strategies to therapeutically target this abundant myeloid population. In this study, we report that inhibition of colony-stimulating factor-1 receptor (CSF-1R) signaling sensitizes TAMs to profound and rapid reprogramming in the presence of a CD40 agonist before their depletion. Despite the short-lived nature of macrophage hyperactivation, combined CSF-1R+CD40 stimulation of macrophages is sufficient to create a proinflammatory tumor milieu that reinvigorates an effective T cell response in transplanted tumors that are either responsive or insensitive to immune checkpoint blockade. The central role of macrophages in regulating preexisting immunity is substantiated by depletion experiments, transcriptome analysis of ex vivo sorted TAMs, and gene expression profiling of whole tumor lysates at an early treatment time point. This approach enabled the identification of specific combination-induced changes among the pleiotropic activation spectrum of the CD40 agonist. In patients, CD40 expression on human TAMs was detected in mesothelioma and colorectal adenocarcinoma.


Subject(s)
Immunity , Macrophages/immunology , Neoplasms/immunology , Neoplasms/pathology , Animals , CD40 Antigens/agonists , CD40 Antigens/metabolism , CD8-Positive T-Lymphocytes/immunology , Female , Humans , Inflammation/pathology , Mice, Inbred BALB C , Mice, Inbred C57BL , Models, Biological , Phenotype , Receptor, Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptor, Macrophage Colony-Stimulating Factor/metabolism
2.
Mol Cancer Ther ; 15(5): 946-57, 2016 05.
Article in English | MEDLINE | ID: mdl-27037412

ABSTRACT

Dysregulated cellular apoptosis and resistance to cell death are hallmarks of neoplastic initiation and disease progression. Therefore, the development of agents that overcome apoptosis dysregulation in tumor cells is an attractive therapeutic approach. Activation of the extrinsic apoptotic pathway is strongly dependent on death receptor (DR) hyperclustering on the cell surface. However, strategies to activate DR5 or DR4 through agonistic antibodies have had only limited clinical success. To pursue an alternative approach for tumor-targeted induction of apoptosis, we engineered a bispecific antibody (BsAb), which simultaneously targets fibroblast-activation protein (FAP) on cancer-associated fibroblasts in tumor stroma and DR5 on tumor cells. We hypothesized that bivalent binding to both FAP and DR5 leads to avidity-driven hyperclustering of DR5 and subsequently strong induction of apoptosis in tumor cells but not in normal cells. Here, we show that RG7386, an optimized FAP-DR5 BsAb, triggers potent tumor cell apoptosis in vitro and in vivo in preclinical tumor models with FAP-positive stroma. RG7386 antitumor efficacy was strictly FAP dependent, was independent of FcR cross-linking, and was superior to conventional DR5 antibodies. In combination with irinotecan or doxorubicin, FAP-DR5 treatment resulted in substantial tumor regression in patient-derived xenograft models. FAP-DR5 also demonstrated single-agent activity against FAP-expressing malignant cells, due to cross-binding of FAP and DR5 across tumor cells. Taken together, these data demonstrate that RG7386, a novel and potent antitumor agent in both mono- and combination therapies, overcomes limitations of previous DR5 antibodies and represents a promising approach to conquer tumor-associated resistance to apoptosis. Mol Cancer Ther; 15(5); 946-57. ©2016 AACR.


Subject(s)
Antibodies, Bispecific/metabolism , Antibodies, Bispecific/pharmacology , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Gelatinases/metabolism , Membrane Proteins/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Serine Endopeptidases/metabolism , Animals , Antibodies, Bispecific/immunology , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Antibody Affinity/immunology , Antineoplastic Agents/immunology , Cell Line, Tumor , Disease Models, Animal , Dose-Response Relationship, Drug , Endopeptidases , Fibroblasts/drug effects , Fibroblasts/metabolism , Gelatinases/immunology , Humans , Membrane Proteins/immunology , Mice , Protein Binding/immunology , Receptors, TNF-Related Apoptosis-Inducing Ligand/immunology , Serine Endopeptidases/immunology , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
3.
MAbs ; 8(4): 811-27, 2016.
Article in English | MEDLINE | ID: mdl-26984378

ABSTRACT

The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the "knobs-into-holes" technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2-3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer.


Subject(s)
Antibodies, Bispecific/pharmacology , Antineoplastic Agents/pharmacology , ErbB Receptors/antagonists & inhibitors , Pancreatic Neoplasms/immunology , Receptor, IGF Type 1/antagonists & inhibitors , Animals , Antibodies, Bispecific/biosynthesis , Antibody Affinity , Antibody-Dependent Cell Cytotoxicity , CHO Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cricetinae , Cricetulus , Humans , Mice , Signal Transduction/drug effects , Xenograft Model Antitumor Assays
4.
Cancer Cell ; 25(6): 846-59, 2014 Jun 16.
Article in English | MEDLINE | ID: mdl-24898549

ABSTRACT

Macrophage infiltration has been identified as an independent poor prognostic factor in several cancer types. The major survival factor for these macrophages is macrophage colony-stimulating factor 1 (CSF-1). We generated a monoclonal antibody (RG7155) that inhibits CSF-1 receptor (CSF-1R) activation. In vitro RG7155 treatment results in cell death of CSF-1-differentiated macrophages. In animal models, CSF-1R inhibition strongly reduces F4/80(+) tumor-associated macrophages accompanied by an increase of the CD8(+)/CD4(+) T cell ratio. Administration of RG7155 to patients led to striking reductions of CSF-1R(+)CD163(+) macrophages in tumor tissues, which translated into clinical objective responses in diffuse-type giant cell tumor (Dt-GCT) patients.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/pharmacology , Colonic Neoplasms/therapy , Macrophages/drug effects , Macrophages/immunology , Receptor, Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptor, Macrophage Colony-Stimulating Factor/immunology , Animals , Antibodies, Monoclonal/pharmacokinetics , Antibodies, Monoclonal, Humanized , Cell Differentiation/physiology , Cell Line, Tumor , Clinical Trials, Phase I as Topic , Cohort Studies , Colonic Neoplasms/immunology , Colonic Neoplasms/metabolism , Female , Humans , Macaca fascicularis , Macrophages/cytology , Macrophages/metabolism , Male , Mice, Inbred C57BL , Models, Molecular , Receptor, Macrophage Colony-Stimulating Factor/metabolism
5.
J Biol Chem ; 289(27): 18693-706, 2014 Jul 04.
Article in English | MEDLINE | ID: mdl-24841203

ABSTRACT

In the present study, we have developed a novel one-arm single chain Fab heterodimeric bispecific IgG (OAscFab-IgG) antibody format targeting the insulin-like growth factor receptor type I (IGF-1R) and the epidermal growth factor receptor (EGFR) with one binding site for each target antigen. The bispecific antibody XGFR is based on the "knob-into-hole" technology for heavy chain heterodimerization with one heavy chain consisting of a single chain Fab to prevent wrong pairing of light chains. XGFR was produced with high expression yields and showed simultaneous binding to IGF-1R and EGFR with high affinity. Due to monovalent binding of XGFR to IGF-1R, IGF-1R internalization was strongly reduced compared with the bivalent parental antibody, leading to enhanced Fc-mediated cellular cytotoxicity. To further increase immune effector functions triggered by XGFR, the Fc portion of the bispecific antibody was glycoengineered, which resulted in strong antibody-dependent cell-mediated cytotoxicity activity. XGFR-mediated inhibition of IGF-1R and EGFR phosphorylation as well as A549 tumor cell proliferation was highly effective and was comparable with a combined treatment with EGFR (GA201) and IGF-1R (R1507) antibodies. XGFR also demonstrated potent anti-tumor efficacy in multiple mouse xenograft tumor models with a complete growth inhibition of AsPC1 human pancreatic tumors and improved survival of SCID beige mice carrying A549 human lung tumors compared with treatment with antibodies targeting either IGF-1R or EGFR. In summary, we have applied rational antibody engineering technology to develop a heterodimeric OAscFab-IgG bispecific antibody, which combines potent signaling inhibition with antibody-dependent cell-mediated cytotoxicity induction and results in superior molecular properties over two established tetravalent bispecific formats.


Subject(s)
Antibodies, Bispecific/immunology , ErbB Receptors/immunology , Immunoglobulin G/immunology , Protein Engineering , Receptor, IGF Type 1/immunology , Single-Chain Antibodies/immunology , Animals , Antibodies, Bispecific/chemistry , Antibodies, Bispecific/metabolism , Antibodies, Bispecific/pharmacology , Binding Sites , Cell Line, Tumor , Cell Proliferation/drug effects , ErbB Receptors/metabolism , Female , Gene Expression Regulation/drug effects , Glycosylation , Humans , Immunoglobulin G/chemistry , Immunoglobulin G/metabolism , Immunoglobulin G/pharmacology , Mice , Pancreatic Neoplasms/pathology , Protein Multimerization , Protein Structure, Quaternary , Protein Transport/drug effects , Receptor, IGF Type 1/metabolism , Signal Transduction/drug effects , Single-Chain Antibodies/chemistry , Single-Chain Antibodies/metabolism , Single-Chain Antibodies/pharmacology , Xenograft Model Antitumor Assays
6.
Arch Biochem Biophys ; 526(2): 206-18, 2012 Oct 15.
Article in English | MEDLINE | ID: mdl-22464987

ABSTRACT

In this study we present novel bispecific antibodies that simultaneously target the insulin-like growth factor receptor type I (IGF-1R) and epidermal growth factor receptor (EGFR). For this purpose disulfide stabilized scFv domains of the EGFR/ADCC antibody GA201 were fused via serine-glycine connectors to the C-terminus of the heavy (XGFR2) or light chain (XGFR4), or the N-termini of the light (XGFR5) or heavy chain (XGFR3) of the IGF-1R antibody R1507 as parental IgG1 antibody. The resulting bispecific IGF-1R-EGFR antibodies XGFR2, XGFR3 and XGFR4 were successfully generated with yields and stability comparable to conventional IgG1 antibodies. They effectively inhibited IGF-1R and EGFR phosphorylation and 3D proliferation of H322M and H460M2 tumor cells, induced strong down-modulation of IGF-1R as well as enhanced EGFR down-modulation compared to the parental EGFR antibody GA201 and were ADCC competent. The bispecific XGFR derivatives showed a strong format dependent influence of N- or C-terminal heavy and light chain scFv attachment on ADCC activity and an increase in receptor downregulation over the parental combination in vitro. XGFR2 and XGFR4 were selected for in vivo evaluation and showed potent anti-tumoral efficacy comparable to the combination of monospecific IGF-1R and EGFR antibodies in subcutaneous BxPC3 and H322M xenograft models. In summary, we have managed to overcome issues of stability and productivity of bispecific antibodies, discovered important antibody fusion protein design related differences on ADCC activity and receptor downmodulation and show that IGF-1R-EGFR antibodies represent an attractive therapeutic strategy to simultaneously target two key components de-regulated in multiple cancer types, with the ultimate goal to avoid the formation of resistance to therapy.


Subject(s)
Antibodies, Bispecific/immunology , Antibodies, Bispecific/therapeutic use , ErbB Receptors/immunology , Immunoglobulin G/immunology , Immunoglobulin G/therapeutic use , Neoplasms/therapy , Receptor, IGF Type 1/immunology , Animals , Antibodies, Bispecific/genetics , Antibody Affinity , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , Cloning, Molecular , ErbB Receptors/metabolism , Female , Humans , Immunoglobulin G/genetics , Immunotherapy , Mice , Mice, SCID , Models, Molecular , Neoplasms/immunology , Neoplasms/metabolism , Phosphorylation/drug effects , Protein Engineering , Receptor, IGF Type 1/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Recombinant Proteins/therapeutic use , Single-Chain Antibodies/genetics , Single-Chain Antibodies/immunology , Single-Chain Antibodies/therapeutic use
7.
J Pathol ; 224(1): 56-66, 2011 May.
Article in English | MEDLINE | ID: mdl-21480230

ABSTRACT

The tumour-modulating effects of the endogenous adaptive immune system are rather paradoxical. Whereas some clinical and experimental observations offer compelling evidence for the existence of immunosurveillance, other studies have revealed promoting effects of the adaptive immune system on primary cancer development and metastatic disease. We examined the functional significance of the adaptive immune system as a regulator of spontaneous HER2(+) breast tumourigenesis and pulmonary metastasis formation, using the MMTV-NeuT mouse model in which mammary carcinogenesis is induced by transgenic expression of the activated HER2/neu oncogene. Although T and B lymphocytes infiltrate human and experimental HER2(+) breast tumours, genetic elimination of the adaptive immune system does not affect development of premalignant hyperplasias or primary breast cancers. In addition, we demonstrate that pulmonary metastasis formation in MMTV-NeuT mice is not dependent on the adaptive immune system. Thus, our findings reveal that spontaneous HER2-driven mammary tumourigenesis and metastasis formation are neither suppressed, nor altered by immunosurveillance mechanisms, nor promoted by the adaptive immune system.


Subject(s)
Lung Neoplasms/secondary , Mammary Neoplasms, Experimental/immunology , Receptor, ErbB-2/metabolism , Adaptive Immunity/immunology , Animals , Cell Transformation, Neoplastic/immunology , Female , Humans , Immune Tolerance/immunology , Immunologic Surveillance/immunology , Lung Neoplasms/immunology , Lymphocyte Subsets/immunology , Mammary Neoplasms, Experimental/metabolism , Mice , Mice, Transgenic , Neoplasm Transplantation , Tumor Microenvironment/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...