ABSTRACT
BACKGROUND AND PURPOSE: Inhibition of the T- and B-cell interaction through the CD40/CD40 ligand (L) axis is a favourable approach for inflammatory disease treatment. Clinical studies of anti-CD40L molecules in autoimmune diseases have met challenges because of thromboembolic events and adverse haemostasis. VIB4920 (formerly MEDI4920) is a novel CD40L antagonist and Tn3 fusion protein designed to prevent adverse haemostasis and immunopharmacology. We evaluated the pharmacokinetics, activity and toxicity of VIB4920 in monkeys. EXPERIMENTAL APPROACH: Cynomolgus monkeys received i.v. or s.c. 5-300 mg·kg-1 VIB4920 or vehicle, once weekly for 1 month (Studies 1 and 2) or 28 weeks (Study 3). VIB4920 exposure and bioavailability were determined using pharmacokinetic analyses, and immune cell population changes via flow cytometry. Pharmacological activity was evaluated by measuring the animals' capacity to elicit an immune response to keyhole limpet haemocyanin (KLH) and tetanus toxoid (TT). KEY RESULTS: VIB4920 demonstrated linear pharmacokinetics at multiple doses. Lymphocyte, monocyte, cytotoxic T-cell and NK cell counts were not significantly different between treatment groups. B-cell counts reduced dose-dependently and the T-cell dependent antibody response to KLH was suppressed by VIB4920 dose-dependently. The recall response to TT was similar across treatment groups. No thromboembolic events or symptoms of immune system dysfunctionality were observed. CONCLUSIONS AND IMPLICATIONS: VIB4920 demonstrated an acceptable safety profile in monkeys. VIB4920 showed favourable pharmacokinetics, dose-dependent inhibition of a neoantigen-specific immune response and no adverse effects on immune function following long-term use. Our data support the use of VIB4920 in clinical trials.
Subject(s)
Autoimmune Diseases , CD40 Ligand , Animals , B-Lymphocytes , Macaca fascicularisABSTRACT
The CD40/CD40L axis plays a central role in the generation of humoral immune responses and is an attractive target for treating autoimmune diseases in the clinic. Here, we report the generation and clinical results of a CD40L binding protein, VIB4920, which lacks an Fc domain, therefore avoiding platelet-related safety issues observed with earlier monoclonal antibody therapeutics that targeted CD40L. VIB4920 blocked downstream CD40 signaling events, resulting in inhibition of human B cell activation and plasma cell differentiation, and did not induce platelet aggregation in preclinical studies. In a phase 1 study in healthy volunteers, VIB4920 suppressed antigen-specific IgG in a dose-dependent fashion after priming and boosting with the T-dependent antigen, KLH. Furthermore, VIB4920 significantly reduced circulating Ki67+ dividing B cells, class-switched memory B cells, and a plasma cell gene signature after immunization. In a phase 1b proof-of-concept study in patients with rheumatoid arthritis, VIB4920 significantly decreased disease activity, achieving low disease activity or clinical remission in more than 50% of patients in the two higher-dose groups. Dose-dependent decreases in rheumatoid factor autoantibodies and Vectra DA biomarker score provide additional evidence that VIB4920 effectively blocked the CD40/CD40L pathway. VIB4920 demonstrated a good overall safety profile in both clinical studies. Together, these data demonstrate the potential of VIB4920 to significantly affect autoimmune disease and humoral immune activation and to support further evaluation of this molecule in inflammatory conditions.
Subject(s)
Autoantibodies/metabolism , Autoimmunity/physiology , CD40 Ligand/metabolism , Cell Proliferation/physiology , Platelet Aggregation/physiology , Arthritis, Rheumatoid/metabolism , B-Lymphocytes/metabolism , CD40 Antigens/metabolism , Healthy Volunteers , HumansABSTRACT
Tn3 proteins are a novel class of binding molecules based on the third fibronectin type III domain of human tenascin C. Target-specific Tn3 proteins are selected from combinatorial libraries in which three surface-exposed loops have been diversified. Here, the cocrystallization of two different Tn3 proteins in complex with CD40L, a therapeutic target for immunological disease, is reported. These crystal structures are the first to be reported of Tn3 proteins and will help to reveal how these engineered molecules achieve specific recognition of a cognate target.
Subject(s)
CD40 Ligand/chemistry , Fibronectins/chemistry , Peptides/chemistry , Amino Acid Sequence , Binding Sites , CD40 Ligand/genetics , CD40 Ligand/isolation & purification , Crystallography, X-Ray , Escherichia coli/genetics , Fibronectins/genetics , Gene Expression , Humans , Molecular Sequence Data , Peptide Library , Peptides/genetics , Peptides/isolation & purification , Protein Binding , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Sequence AlignmentABSTRACT
Increased concentrations of DNA-containing immune complexes in the serum are associated with systemic autoimmune diseases such as lupus. Stimulation of Toll-like receptor 9 (TLR9) by DNA is important in the activation of plasmacytoid dendritic cells and B cells. Here we show that HMGB1, a nuclear DNA-binding protein released from necrotic cells, was an essential component of DNA-containing immune complexes that stimulated cytokine production through a TLR9-MyD88 pathway involving the multivalent receptor RAGE. Moreover, binding of HMGB1 to class A CpG oligodeoxynucleotides considerably augmented cytokine production by means of TLR9 and RAGE. Our data demonstrate a mechanism by which HMGB1 and RAGE activate plasmacytoid dendritic cells and B cells in response to DNA and contribute to autoimmune pathogenesis.
Subject(s)
HMGB1 Protein/physiology , Lupus Erythematosus, Systemic/immunology , Oligodeoxyribonucleotides/immunology , Receptor for Advanced Glycation End Products/physiology , Toll-Like Receptor 9/metabolism , Animals , Antigen-Antibody Complex , B-Lymphocytes , CpG Islands , DNA-Binding Proteins/immunology , Dendritic Cells/cytology , Dendritic Cells/metabolism , HMGB1 Protein/biosynthesis , Lupus Erythematosus, Systemic/metabolism , Lupus Erythematosus, Systemic/pathology , Mice , Mice, Inbred C57BL , Receptor for Advanced Glycation End Products/biosynthesis , Receptors, Cell Surface/metabolism , Toll-Like Receptor 9/physiologyABSTRACT
The identification and optimization of a series of acylguanidine-based melanocortin-4 receptor antagonists is discussed.
Subject(s)
Guanidine/chemistry , Receptor, Melanocortin, Type 4/antagonists & inhibitors , Sulfhydryl Compounds/chemistry , Animals , Binding Sites , Brain/metabolism , Guanidine/analogs & derivatives , Guanidine/pharmacology , Inhibitory Concentration 50 , Mice , Plasma/metabolism , Structure-Activity Relationship , Sulfhydryl Compounds/pharmacology , Time FactorsABSTRACT
A novel series of imidazole-based small molecule antagonists of the melanocortin 4 receptor (MC4-R) is reported. Members of this series have been identified, which exhibit sub-micromolar binding affinity for the MC4-R, functional potency <100nM, and good oral exposure in rat. Antagonists of the MC4-R are potentially useful in the therapeutic treatment of involuntary weight loss due to advanced age or disease (e.g. cancer or AIDS), an area of large, unmet medical need.
Subject(s)
Body Weight/drug effects , Imidazoles/chemical synthesis , Receptor, Melanocortin, Type 4/antagonists & inhibitors , Animals , Binding Sites , Body Weight/physiology , Cells, Cultured , Imidazoles/pharmacology , Rats , Receptor, Melanocortin, Type 4/metabolism , Structure-Activity RelationshipABSTRACT
The melanocortin 4 receptor (MC4R) plays an important role in body weight regulation and energy homeostasis. Administration of peptidic MC4R antagonists (usually by intracerebro ventricular injection) has been shown in the literature to increase body weight and/or food intake in several rodent models. We report here the identification of a novel nonpeptidic MC4R antagonist and its effects on tumor-induced weight loss in mice following peripheral administration.
