ABSTRACT
Progressive upregulation of checkpoints on tumor-infiltrating lymphocytes promotes an immunosuppressive tumor microenvironment, severely compromising tumor immunity. Lymphocyte activation gene-3 (LAG-3) is a coinhibitory receptor associated with impaired T-cell function and is frequently coexpressed with programmed cell death protein-1 (PD-1) in the context of human cancers. Targeting LAG-3 in conjunction with PD-1 thus represents a strategy to amplify and broaden the therapeutic impact of PD-1 blockade alone. We have generated a high affinity and selective humanized monoclonal IgG4 antibody, TSR-033, which binds human LAG-3 and serves as a functional antagonist, enhancing in vitro T-cell activation both in mixed lymphocyte reactions and staphylococcal enterotoxin B-driven stimulation assays. In a humanized mouse non-small cell lung carcinoma model, TSR-033 boosted the antitumor efficacy of PD-1 monotherapy, with a concomitant increase in immune activation. Analogous studies in a murine syngeneic tumor model using surrogate antibodies demonstrated significant synergy between LAG-3 and PD-1 blockade-combination treatment led to a marked improvement in therapeutic efficacy, increased T-cell proliferation, IFNγ production, and elicited durable immunologic memory upon tumor rechallenge. Taken together, the pharmacologic activity of TSR-033 demonstrates that it is a potent anti-LAG-3 therapeutic antibody and supports its clinical investigation in cancer patients.
Subject(s)
Antibodies, Monoclonal, Humanized , Antigens, CD/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Programmed Cell Death 1 Receptor/immunology , T-Lymphocytes/drug effects , Animals , Antibodies, Monoclonal, Humanized/immunology , Antibodies, Monoclonal, Humanized/pharmacology , Antigens, CD/immunology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/immunology , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Disease Models, Animal , Humans , Immunoglobulin G/immunology , Immunoglobulin G/pharmacology , Lymphocytes, Tumor-Infiltrating/drug effects , Mice , Mice, Transgenic , Programmed Cell Death 1 Receptor/antagonists & inhibitors , T-Lymphocytes/immunology , Tumor Microenvironment/drug effects , Tumor Microenvironment/immunology , Lymphocyte Activation Gene 3 ProteinABSTRACT
The insulin-like growth factor-1 receptor (IGF-1R) plays an important role in the regulation of cell growth and differentiation, and in protection from apoptosis. IGF-1R has been shown to be an appealing target for the treatment of human cancer. Herein, we report the synthesis, structure-activity relationships (SAR), X-ray cocrystal structure and in vivo tumor study results for a series of 2,4-bis-arylamino-1,3-pyrimidines.
Subject(s)
Protein Kinase Inhibitors/chemistry , Pyrimidines/chemistry , Quinolines/chemical synthesis , Receptor, IGF Type 1/antagonists & inhibitors , Animals , Binding Sites , Crystallography, X-Ray , Drug Evaluation, Preclinical , Humans , Mice , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Pyrimidines/chemical synthesis , Pyrimidines/pharmacokinetics , Quinolines/chemistry , Quinolines/pharmacokinetics , Receptor, IGF Type 1/metabolism , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
PURPOSE: Hepatocyte growth factor (HGF/SF) and its receptor c-Met have previously been shown to be up-regulated in multiple human cancers, including glioblastoma multiforme. To better understand if AMG 102, a fully human, anti-HGF/SF-neutralizing antibody, could be incorporated into current clinical practice, AMG 102 was tested preclinically in combination with temozolomide or docetaxel to determine if enhanced efficacy was observed compared with AMG 102 alone. EXPERIMENTAL DESIGN: The effects of AMG 102 were tested for antiproliferative activity in combination with temozolomide or docetaxel on U-87 MG cells in vitro and for antitumor activity in a U-87 MG xenograft model in vivo. Apoptotic activity was also measured for AMG 102 and docetaxel combined in vitro. RESULTS: Treatment with temozolomide combined with AMG 102 resulted in increased inhibition of cell growth in vitro compared with treatment with either single agent alone. In U-87 MG xenografts in vivo, AMG 102 combined with temozolomide or docetaxel significantly increased the inhibitory effect on tumor growth when compared with treatment with either agent alone (P < 0.0001 and P < 0.015, respectively). In vitro, docetaxel alone induced both caspase-3/7 activity as well as poly(ADP)ribose polymerase and caspase-7 cleavage in U-87 MG cells; these events were enhanced when used in combination with AMG 102. Importantly, there was no evidence of interference between AMG 102 and either temozolomide or docetaxel in vitro or in vivo. CONCLUSION: These studies support testing of AMG 102 in combination with temozolomide or docetaxel. Such combinations may represent promising, novel clinical therapeutic strategies for cancers that are dependent on the HGF/SF/SF:c-Met pathway in the oncology setting.
