ABSTRACT
Preclinical and clinical studies conducted in the mid-1990s reported strong association and causality between the T-cell helper (T(H)) 1 inductor cytokine interleukin (IL)-12 and numerous immune-mediated disorders, which spurred the development of therapeutic agents targeting IL-12 function. One of the first to enter the clinic, ustekinumab, is a human monoclonal antibody (mAb) that binds to the p40 subunit of IL-12. Subsequent to the generation of ustekinumab, it was discovered that IL-23 also contains the p40 subunit. Thus, although ustekinumab was designed to target IL-12, it also modulates IL-23, a cytokine important to the development and/or maintenance of T(H)17 cells. Clinical observations established that IL-12/23p40 is integral to the pathologies of psoriasis, psoriatic arthritis and Crohn's disease. The molecular and cellular evaluations conducted in ustekinumab clinical programs have provided numerous insights into the pathologic processes of these disorders, illustrating how a novel molecular entity can contribute to our understanding of disease. The individual contributions of these cytokines to specific pathologies require investigation and clinical evaluation of the role of IL-12- and IL-23-specific inhibitors.
Subject(s)
Antibodies, Monoclonal/pharmacology , Drug Delivery Systems/methods , Interleukin-12/antagonists & inhibitors , Interleukin-23/antagonists & inhibitors , Signal Transduction/physiology , Animals , Antibodies, Monoclonal, Humanized , Humans , Signal Transduction/drug effects , UstekinumabABSTRACT
Rational design based on a pharmacophore of CCR2 antagonists reported in the literature identified lead compound 9a with potent inhibitory activity against human CCR2 (hCCR2) but moderate activity against murine CCR2 (mCCR2). Modification on 9a led to the discovery of a potent CCR2 antagonist 21 (INCB3344) with IC(50) values of 5.1 nM (hCCR2) and 9.5 nM (mCCR2) in binding antagonism and 3.8 nM (hCCR2) and 7.8 nM (mCCR2) in antagonism of chemotaxis activity. INCB3344 exhibited >100-fold selectivity over other homologous chemokine receptors, a free fraction of 24% in human serum and 15% in mouse serum, and an oral bioavailability of 47% in mice, suitable as a tool compound for target validation in rodent models.
Subject(s)
Pyrrolidines/chemistry , Receptors, CCR2/antagonists & inhibitors , Administration, Oral , Animals , Drug Evaluation, Preclinical , Humans , Mice , Protein Binding , Pyrrolidines/chemical synthesis , Pyrrolidines/pharmacokinetics , Rats , Receptors, CCR2/metabolism , Structure-Activity RelationshipABSTRACT
This report describes the characterization of INCB3344, a novel, potent and selective small molecule antagonist of the mouse CCR2 receptor. The lack of rodent cross-reactivity inherent in the small molecule CCR2 antagonists discovered to date has precluded pharmacological studies of antagonists of this receptor and its therapeutic relevance. In vitro, INCB3344 inhibits the binding of CCL2 to mouse monocytes with nanomolar potency (IC(50) = 10 nM) and displays dose-dependent inhibition of CCL2-mediated functional responses such as ERK phosphorylation and chemotaxis with similar potency. Against a panel of G protein-coupled receptors that includes other CC chemokine receptors, INCB3344 is at least 100-fold selective for CCR2. INCB3344 possesses good oral bioavailability and systemic exposure in rodents that allows in vivo pharmacological studies. INCB3344 treatment results in a dose-dependent inhibition of macrophage influx in a mouse model of delayed-type hypersensitivity. The histopathological analysis of tissues from the delayed-type hypersensitivity model demonstrates that inhibition of CCR2 leads to a substantial reduction in tissue inflammation, suggesting that macrophages play an orchestrating role in immune-based inflammatory reactions. These results led to the investigation of INCB3344 in inflammatory disease models. We demonstrate that therapeutic dosing of INCB3344 significantly reduces disease in mice subjected to experimental autoimmune encephalomyelitis, a model of multiple sclerosis, as well as a rat model of inflammatory arthritis. In summary, we present the first report on the pharmacological characterization of a selective, potent and rodent-active small molecule CCR2 antagonist. These data support targeting this receptor for the treatment of chronic inflammatory diseases.
Subject(s)
Pyrrolidines/pharmacology , Receptors, Chemokine/antagonists & inhibitors , Animals , Arthritis, Experimental/drug therapy , Cell Line , Chemotaxis, Leukocyte/drug effects , Chemotaxis, Leukocyte/immunology , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Encephalomyelitis, Autoimmune, Experimental/prevention & control , Female , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Monocytes/drug effects , Protein Binding/drug effects , Protein Binding/immunology , Pyrrolidines/pharmacokinetics , Rats , Rats, Inbred Lew , Receptors, CCR2 , Receptors, Chemokine/deficiency , Receptors, Chemokine/genetics , Structure-Activity RelationshipABSTRACT
Inflammatory diseases affect a significant portion of the population worldwide and have been intensely studied for several decades. The advent of transgenic technology has allowed researchers to study individual gene contributions to the pathogenesis of these diseases. This has been done using standard inflammatory disease models in transgenic animals and by identifying novel models through the spontaneous generation of disease in the transgenic animal. Recent advances have been made in the understanding of rheumatoid arthritis, pulmonary inflammation, multiple sclerosis and inflammatory bowel disease through the use of transgenic animals in models of human inflammatory disease.
