Leibel RL, Kussie P. Monoclonal antibody antagonists of hypothalamic FGFR1 cause potent but reversible hypophagia and weight loss in rodents and monkeys. Am J Physiol Endocrinol Metab 292: E964 -E976, 2007. First published November 28, 2006; doi:10.1152/ajpendo.00089.2006.-We generated three fully human monoclonal antibody antagonists against fibroblast growth factor receptor-1 (FGFR1) that potently block FGF signaling. We found that antibodies targeting the c-splice form of the receptor (FGFR1c) were anorexigenic when administered intraperitoneally three times weekly to mice, resulting in rapid, dose-dependent weight loss that plateaued (for doses Ͼ4 mg/kg) at 35-40% in 2 wk. Animals appeared healthy during treatment and regained their normal body weights and growth trajectories upon clearance of the antibodies from the bloodstream. Measurements of food consumption and energy expenditure indicated that the rapid weight loss was induced primarily by decreased energy intake and not by increased energy expenditure or cachexia and was accompanied by a greater reduction in fat than lean body mass. Hypophagia was not caused through malaise or illness, as indicated by absence of conditioned taste aversion, pica behavior, and decreased need-induced salt intake in rats. In support of a hypothalamic site of action, we found that, after intraperitoneal injections, anti-FGFR1c (IMC-A1), but not a control antibody, accumulated in the median eminence and adjacent mediobasal hypothalamus and that FGFR1c is enriched in the hypothalamus of mice. Furthermore, a single intracerebroventricular administration of 3 g of IMC-A1 via the 3rd ventricle to mice caused an ϳ36% reduction in food intake and an ϳ6% weight loss within the ensuing 24 h. Our data suggest that FGF signaling through FGFR1c may play a physiological role in hypothalamic feeding circuit and that blocking it leads to hypophagia and weight loss. energy homeostasis; hypothalamus; fibroblast growth factor receptor; food intake; obesity THE FGF-FGFR AXIS (fibroblast growth factor-fibroblast growth factor receptor) plays a central role in embryonic development, osteogenesis, tissue maintenance, and repair (24,42,46). FGF signaling is complex: at least 22 ligands are known that signal through four distinct cell surface receptors (FGFR1, -2, -3, and -4). Some FGF-knockouts (such as FGF4, -8, -9, -10, -18 and FGFR1) are embryonic lethal; others generate relatively mild phenotypes due to considerable redundancy in the signaling pathway(s) (10,24,42,46). Loss-of-function mutations in FGFR1 have been implicated in instances of hypogonadotropic hypogonadism (Kallmann syndrome), indicating a role for the receptor in human central nervous system (CNS)/hypothalamic development (45). FGF ligand-receptor binding induces receptor dimerization and autophosphorylation, leading to downstream activation of effector molecules such as mitogen-activating protein kinase (MAPK). In FGFR1, -2, and -3, alternative splicing of the exons encoding the third IgG-like domain produces either the b-or...
The programmed cell death protein 1 receptor (PD-1) and programmed death ligand 1 (PD-L1) coinhibitory pathway suppresses T-cell–mediated immunity. We hypothesized that cotargeting of PD-1 and PD-L1 with a bispecific antibody molecule could provide an alternative therapeutic approach, with enhanced antitumor activity, compared with monospecific PD-1 and PD-L1 antibodies. Here, we describe LY3434172, a bispecific IgG1 mAb with ablated Fc immune effector function that targets both human PD-1 and PD-L1. LY3434172 fully inhibited the major inhibitory receptor–ligand interactions in the PD-1 pathway. LY3434172 enhanced functional activation of T cells in vitro compared with the parent anti–PD-1 and anti–PD-L1 antibody combination or respective monotherapies. In mouse tumor models reconstituted with human immune cells, LY3434172 therapy induced dramatic and potent antitumor activity compared with each parent antibody or their combination. Collectively, these results demonstrated the enhanced immunomodulatory (immune blockade) properties of LY3434172, which improved antitumor immune response in preclinical studies, thus supporting its evaluation as a novel bispecific cancer immunotherapy.
Activating mutations in fibroblast growth factor receptor 3 (FGFR3) have been identified in multiple types of human cancer and in congenital birth defects. In human lung cancer, fibroblast growth factor 9 (FGF9), a high-affinity ligand for FGFR3, is overexpressed in 10% of primary resected non-small cell lung cancer (NSCLC) specimens. Furthermore, in a mouse model where FGF9 can be induced in lung epithelial cells, epithelial proliferation and ensuing tumorigenesis is dependent on FGFR3. To develop new customized therapies for cancers that are dependent on FGFR3 activation, we have used this mouse model to evaluate a human monoclonal antibody (D11) with specificity for the extracellular ligand-binding domain of FGFR3, that recognizes both human and mouse forms of the receptor. Here, we show that D11 effectively inhibits signaling through FGFR3 in vitro, inhibits the growth of FGFR3-dependent FGF9-induced lung adenocarcinoma in mice, and reduces tumor-associated morbidity. Given the potency of FGF9 in this mouse model and the absolute requirement for signaling through FGFR3, this study validates the D11 antibody as a potentially useful and effective reagent for treating human cancers or other pathologies that are dependent on activation of FGFR3.
BackgroundModulation of the PD-1/PD-L1 axis through antagonist antibodies that block either receptor or ligand has been shown to reinvigorate the function of tumor-specific T cells and unleash potent anti-tumor immunity, leading to durable objective responses in a subset of patients across multiple tumor types.ResultsHere we describe the discovery and preclinical characterization of LY3300054, a fully human IgG1λ monoclonal antibody that binds to human PD-L1 with high affinity and inhibits interactions of PD-L1 with its two cognate receptors PD-1 and CD80. The functional activity of LY3300054 on primary human T cells is evaluated using a series of in vitro T cell functional assays and in vivo models using human-immune reconstituted mice. LY3300054 is shown to induce primary T cell activation in vitro, increase T cell activation in combination with anti-CTLA4 antibody, and to potently enhance anti-tumor alloreactivity in several xenograft mouse tumor models with reconstituted human immune cells. High-content molecular analysis of tumor and peripheral tissues from animals treated with LY3300054 reveals distinct adaptive immune activation signatures, and also previously not described modulation of innate immune pathways.ConclusionsLY3300054 is currently being evaluated in phase I clinical trials for oncology indications.Electronic supplementary materialThe online version of this article (10.1186/s40425-018-0329-7) contains supplementary material, which is available to authorized users.
<p>Supplementary Figures 1-9 and Supplementary Tables 1-3</p>
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