ABSTRACT
Our research on hydantoin based TNF-α converting enzyme (TACE) inhibitors led to fused bi-heteroaryl hydantoin series that demonstrate sub-nanomolar potency (Ki) as well as excellent activity in human whole blood (hWBA). However, lead compound 2 posed some formulation challenges which prevented it for further development. A prodrug approach was investigated to address this issue. The pivalate prodrug 3 can be formulated as stable neutral form and demonstrated improved DMPK properties when compared with parent compound.
Subject(s)
ADAM17 Protein/antagonists & inhibitors , Hydantoins/chemistry , Hydantoins/chemical synthesis , Hydantoins/pharmacology , Pentanoic Acids/chemistry , Prodrugs/chemical synthesis , Prodrugs/pharmacology , ADAM17 Protein/metabolism , Administration, Oral , Animals , Area Under Curve , Dogs , Enzyme Activation/drug effects , Half-Life , Haplorhini , Humans , Hydantoins/administration & dosage , Hydantoins/pharmacokinetics , Pentanoic Acids/administration & dosage , Pentanoic Acids/pharmacokinetics , Prodrugs/administration & dosage , Prodrugs/pharmacokinetics , ROC Curve , Rats , Structure-Activity RelationshipABSTRACT
We have identified a series of hydantoin-derived TNF-a converting enzyme (TACE) inhibitors containing a pendant fused bi-heteroaryl group, which demonstrate sub-nanomolar potency (Ki), excellent activity in human whole blood assay, and improved DMPK profiles over prior series.
Subject(s)
ADAM17 Protein/antagonists & inhibitors , Hydantoins/chemistry , Protease Inhibitors/chemistry , ADAM17 Protein/metabolism , Animals , Area Under Curve , Dogs , Enzyme Activation/drug effects , Half-Life , Haplorhini , Humans , Hydantoins/chemical synthesis , Hydantoins/pharmacology , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , ROC Curve , Rats , Structure-Activity RelationshipABSTRACT
IRAK4 has been identified as potential therapeutic target for inflammatory and autoimmune diseases. Herein we report the identification and initial SAR studies of a new class of pyrazole containing IRAK4 inhibitors designed to expand chemical diversity and improve off target activity of a previously identified series. These compounds maintain potent IRAK4 activity and desirable ligand efficiency. Rat clearance and a variety of off target activities were also examined, resulting in encouraging data with tractable SAR.
Subject(s)
Interleukin-1 Receptor-Associated Kinases/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Pyrazoles/chemistry , Animals , Binding Sites , Crystallography, X-Ray , Half-Life , Humans , Interleukin-1 Receptor-Associated Kinases/metabolism , Ligands , Molecular Dynamics Simulation , Protein Binding , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacokinetics , Protein Structure, Tertiary , Pyrazoles/metabolism , Pyrazoles/pharmacokinetics , Rats , Structure-Activity RelationshipABSTRACT
IRAK4 plays a key role in TLR/IL-1 signaling. Previous efforts identified a series of aminopyrimidine IRAK4 inhibitors that possess good potency, but modest kinase selectivity. Exploration of substituents at the C-2 and C-5 positions generated compounds that maintained IRAK4 potency and improved kinase selectivity. Additionally, it was found that the pyrimidine core could be replaced with a pyridine and still retain potency and kinase selectivity. The optimization efforts led to compound 26 which had an IRAK4 IC50 of 0.7 nM, an IC50 of 55 nM on THP-1 cells stimulated with LPS, a TLR4 agonist, and greater than 100-fold selectivity versus 96% of a panel of 306 kinases.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Interleukin-1 Receptor-Associated Kinases/antagonists & inhibitors , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cell Line , High-Throughput Screening Assays , Humans , Lipopolysaccharides/pharmacology , Structure-Activity Relationship , Substrate Specificity , Toll-Like Receptor 4/antagonists & inhibitorsABSTRACT
A unified strategy was conceived and implemented to deliver conformationally constrained anilides based on their preferred cis-amide conformers. The imidazole/triazole mimicing amide bonds were designed, building upon an earlier discovery of a novel series of tricyclic lactams MK2 kinase inhibitors. This approach enabled rapid, modular synthesis of structurally novel analogs. The efficient SAR development led to the discovery of low molecular weight and potent MK2 non-ATP competitive inhibitors with good ligand efficiency, which led to improved permeability and oral exposure in rats.
Subject(s)
Amides/chemistry , Azoles/pharmacology , Drug Discovery , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Azoles/chemical synthesis , Azoles/chemistry , Dose-Response Relationship, Drug , Intracellular Signaling Peptides and Proteins/metabolism , Molecular Conformation , Permeability/drug effects , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/metabolism , Rats , Structure-Activity RelationshipABSTRACT
Conformation restriction of linear N-alkylanilide MK2 inhibitors to their E-conformer was developed. This strategy enabled rapid advance in identifying a series of potent non-ATP competitive inhibitors that exhibited cell based activity in anti-TNFα assay.
Subject(s)
Anilides/chemistry , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Lactams/chemistry , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/antagonists & inhibitors , Adenosine Triphosphate/chemistry , Adenosine Triphosphate/metabolism , Anilides/chemical synthesis , Anilides/metabolism , Binding, Competitive , Drug Evaluation, Preclinical , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Lactams/chemical synthesis , Lactams/metabolism , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/metabolism , Protein Serine-Threonine Kinases/metabolism , Stereoisomerism , Structure-Activity RelationshipABSTRACT
The optimization of oxazole-based PDE4 inhibitor 1 has led to the identification of both oral (compound 16) and inhaled (compound 34) PDE4 inhibitors. Selectivity against PDE10/PDE11, off target screening, and in vivo activity in the rat are discussed.
Subject(s)
Cyclic Nucleotide Phosphodiesterases, Type 4/chemistry , Oxazoles/chemistry , Proline/analogs & derivatives , Quinolines/chemical synthesis , Administration, Oral , Animals , Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism , Drug Evaluation, Preclinical , Half-Life , Inhalation , Oxazoles/chemical synthesis , Oxazoles/pharmacokinetics , Phosphodiesterase 4 Inhibitors/chemical synthesis , Phosphodiesterase 4 Inhibitors/chemistry , Phosphodiesterase 4 Inhibitors/pharmacokinetics , Proline/chemical synthesis , Proline/chemistry , Proline/pharmacokinetics , Quinolines/chemistry , Quinolines/pharmacokinetics , Rats , Rats, Sprague-Dawley , Structure-Activity RelationshipABSTRACT
BACKGROUND: The CXCR3 receptor and its three interferon-inducible ligands (CXCL9, CXCL10 and CXCL11) have been implicated as playing a central role in directing a Th1 inflammatory response. Recent studies strongly support that the CXCR3 receptor is a very attractive therapeutic target for treating autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and psoriasis, and to prevent transplant rejection. We describe here the in vitro and in vivo pharmacological characterizations of a novel and potent small molecule CXCR3 antagonist, SCH 546738. RESULTS: In this study, we evaluated in vitro pharmacological properties of SCH 546738 by radioligand receptor binding and human activated T cell chemotaxis assays. In vivo efficacy of SCH 546738 was determined by mouse collagen-induced arthritis, rat and mouse experimental autoimmune encephalomyelitis, and rat cardiac transplantation models. We show that SCH 546738 binds to human CXCR3 with a high affinity of 0.4 nM. In addition, SCH 546738 displaces radiolabeled CXCL10 and CXCL11 from human CXCR3 with IC50 ranging from 0.8 to 2.2 nM in a non-competitive manner. SCH 546738 potently and specifically inhibits CXCR3-mediated chemotaxis in human activated T cells with IC90 about 10 nM. SCH 546738 attenuates the disease development in mouse collagen-induced arthritis model. SCH 546738 also significantly reduces disease severity in rat and mouse experimental autoimmune encephalomyelitis models. Furthermore, SCH 546738 alone achieves dose-dependent prolongation of rat cardiac allograft survival. Most significantly, SCH 546738 in combination with CsA supports permanent engraftment. CONCLUSIONS: SCH 546738 is a novel, potent and non-competitive small molecule CXCR3 antagonist. It is efficacious in multiple preclinical disease models. These results demonstrate that therapy with CXCR3 antagonists may serve as a new strategy for treatment of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis, and to prevent transplant rejection.
Subject(s)
Autoimmune Diseases/drug therapy , Chemotaxis, Leukocyte/drug effects , Graft Rejection/prevention & control , Graft Survival/drug effects , Heart Transplantation , Piperazines/pharmacology , Pyrazinamide/analogs & derivatives , Receptors, CXCR3/antagonists & inhibitors , T-Lymphocytes/drug effects , Animals , Arthritis, Experimental/drug therapy , Arthritis, Experimental/immunology , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/immunology , Autoimmune Diseases/immunology , Chemotaxis, Leukocyte/immunology , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Encephalomyelitis, Autoimmune, Experimental/immunology , Graft Rejection/immunology , Humans , In Vitro Techniques , Mice , Multiple Sclerosis/drug therapy , Multiple Sclerosis/immunology , Protein Binding , Pyrazinamide/pharmacology , Radioligand Assay , Rats , T-Lymphocytes/immunologyABSTRACT
Protein ectodomain shedding is crucial for cell-cell interactions because it controls the bioavailability of soluble tumor necrosis factor-α (TNFα) and ligands of the epidermal growth factor (EGF) receptor, and the release of many other membrane proteins. Various stimuli can rapidly trigger ectodomain shedding, yet much remains to be learned about the identity of the enzymes that respond to these stimuli and the mechanisms underlying their activation. Here, we demonstrate that the membrane-anchored metalloproteinase ADAM17, but not ADAM10, is the sheddase that rapidly responds to the physiological signaling pathways stimulated by thrombin, EGF, lysophosphatidic acid and TNFα. Stimulation of ADAM17 is swift and quickly reversible, and does not depend on removal of its inhibitory pro-domain by pro-protein convertases, or on dissociation of an endogenous inhibitor, TIMP3. Moreover, activation of ADAM17 by physiological stimuli requires its transmembrane domain, but not its cytoplasmic domain, arguing against inside-out signaling via cytoplasmic phosphorylation as the underlying mechanism. Finally, experiments with the tight binding hydroxamate inhibitor DPC333, used here to probe the accessibility of the active site of ADAM17, demonstrate that this inhibitor can quickly bind to ADAM17 in stimulated, but not quiescent cells. These findings support the concept that activation of ADAM17 involves a rapid and reversible exposure of its catalytic site.
Subject(s)
ADAM Proteins/metabolism , Tissue Inhibitor of Metalloproteinase-3/metabolism , ADAM17 Protein , Animals , COS Cells , Catalytic Domain , Cells, Cultured , Chlorocebus aethiops , Down-Regulation , Humans , Metalloproteases/antagonists & inhibitors , Metalloproteases/metabolism , Mice , Phosphorylation , Signal Transduction , TransfectionABSTRACT
A three-step protocol for SAR development was introduced and applied to the SAR studies of the MK2 inhibitor program. Following this protocol, key conformational features and functional groups for improving MK2 inhibitor activity were quickly identified. Through this effort, the initial gap observed between in vitro binding activity and cellular activity in the lead identification stage was very much reduced. Compound 28 was identified with single digit binding activity (IC(50)=8 nM) and good cellular activity (EC(50)=310 nM). This provides further evidence that non-ATP-competitive binding MK2 inhibitors are feasible by targeting the outside ATP pocket.
Subject(s)
Chemistry, Pharmaceutical/methods , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Adenosine Triphosphate/chemistry , Animals , Drug Design , Humans , Inhibitory Concentration 50 , Mice , Models, Chemical , Molecular Conformation , Protein Binding , Structure-Activity RelationshipABSTRACT
TNF-α converting enzyme (TACE) inhibitors are promising agents to treat inflammatory disorders and cancer. We have investigated novel tartrate diamide TACE inhibitors where the tartrate core binds to zinc in a unique tridentate fashion. Incorporating (R)-2-(2-N-alkylaminothiazol-4-yl)pyrrolidines into the left hand side amide of the tartrate scaffold led to the discovery of potent and selective TACE inhibitors, some of which exhibited good rat oral bioavailability.
Subject(s)
ADAM Proteins/antagonists & inhibitors , Amides/pharmacology , Enzyme Inhibitors/pharmacology , Pyrrolidines/chemistry , Tartrates/chemistry , ADAM17 Protein , Amides/chemical synthesis , Amides/chemistry , Animals , Biological Availability , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Molecular Structure , RatsABSTRACT
Neutrophils and monocytes are abundantly represented in the synovial fluid and tissue in rheumatoid arthritis patients. We therefore explored the effects of small molecule chemokine receptor antagonists to block migration of these cells in anti-collagen antibody-induced arthritis. Targeting neutrophil migration with the CXCR2/CXCR1 antagonist SCH563705 led to a dose-dependent decrease in clinical disease scores and paw thickness measurements and clearly reduced inflammation and bone and cartilage degradation based on histopathology and paw cytokine analyses. In contrast, targeting monocyte migration with the CCR2 antagonist MK0812 had no effect on arthritis disease severity. The pharmacodynamic activities of both SCH563705 and MK0812 were verified by assessing their effects on the peripheral blood monocyte and neutrophil populations. SCH563705 selectively reduced the peripheral blood neutrophil frequency, and caused an elevation in the CXCR2 ligand CXCL1. MK0812 selectively reduced the peripheral blood monocyte frequency, and caused an elevation in the CCR2 ligand CCL2. The much greater impact of CXCR2/CXCR1 antagonism relative to CCR2 antagonism in this model of arthritis highlights the therapeutic potential for targeting CXCR2/CXCR1 in human arthritides.
Subject(s)
Arthritis, Rheumatoid/immunology , Cell Movement/drug effects , Neutrophils/drug effects , Receptors, CCR2/antagonists & inhibitors , Receptors, Interleukin-8B/antagonists & inhibitors , Animals , Disease Models, Animal , Female , Mice , Mice, Inbred BALB C , Neutrophils/immunology , Receptors, CCR2/physiology , Receptors, Interleukin-8B/physiology , Synovial Fluid/drug effects , Synovial Fluid/immunologyABSTRACT
We report further expansion of the structure activity relationship (SAR) on the triaryl bis sulfone class of compounds (I), which are potent CB(2) receptor ligands with excellent selectivity over the CB(1) receptor. This study was extended to B ring changes, followed by simultaneous optimization of the A-, B-, and C-rings. Compound 42 has excellent CB(2) potency, selectivity and rat exposure.
Subject(s)
Receptor, Cannabinoid, CB2/drug effects , Sulfones/chemistry , Sulfones/pharmacology , Animals , Ligands , Rats , Receptor, Cannabinoid, CB2/metabolism , Structure-Activity Relationship , Sulfones/metabolismABSTRACT
The triaryl bis-sulfone 1 was modified by converting the aryl A-ring to a piperidine ring. The piperidine ring was further elaborated to a spirocyclopropyl piperidine moiety. The effect on CB2 binding potency, rat calcium channel affinity, and CYP 2C9 inhibition is described.
Subject(s)
Receptor, Cannabinoid, CB2/antagonists & inhibitors , Sulfonamides/chemical synthesis , Sulfones/chemistry , Sulfones/chemical synthesis , Animals , Calcium Channels/metabolism , Cytochrome P-450 Enzyme System , Drug Inverse Agonism , Humans , Piperidines/chemistry , Rats , Receptor, Cannabinoid, CB2/metabolism , Structure-Activity Relationship , Sulfonamides/chemistry , Sulfonamides/pharmacokinetics , Sulfones/pharmacokineticsABSTRACT
We disclose further optimization of hydantoin TNF-alpha convertase enzyme (TACE) inhibitors. SAR with respect to the non-prime region of TACE active site was explored. A series of biaryl substituted hydantoin compounds was shown to have sub-nanomolar K(i), good rat PK, and good selectivity versus MMP-1, -2, -3, -7, -9, and -13.
Subject(s)
ADAM Proteins/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , ADAM17 Protein , Animals , Rats , Structure-Activity RelationshipABSTRACT
The syntheses and structure-activity relationships of the tartrate-based TACE inhibitors are discussed. The optimization of both the prime and non-prime sites led to compounds with picomolar activity. Several analogs demonstrated good rat pharmacokinetics.
Subject(s)
ADAM Proteins/antagonists & inhibitors , Protease Inhibitors/chemistry , Tartrates/chemistry , ADAM Proteins/metabolism , ADAM17 Protein , Animals , Binding Sites , Computer Simulation , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacokinetics , Rats , Structure-Activity Relationship , Tartrates/chemical synthesis , Tartrates/pharmacokineticsABSTRACT
Our research on hydantoin based TNF-α converting enzyme (TACE) inhibitors has led to an acetylene containing series that demonstrates sub-nanomolar potency (K(i)) as well as excellent activity in human whole blood. These studies led to the discovery of highly potent TACE inhibitors with good DMPK profiles.
Subject(s)
ADAM Proteins/antagonists & inhibitors , Anti-Inflammatory Agents/chemistry , Arthritis, Rheumatoid/drug therapy , Protease Inhibitors/chemistry , ADAM Proteins/metabolism , ADAM17 Protein , Acetylene/analogs & derivatives , Acetylene/pharmacokinetics , Acetylene/therapeutic use , Animals , Anti-Inflammatory Agents/pharmacokinetics , Anti-Inflammatory Agents/therapeutic use , Dogs , Haplorhini , Humans , Protease Inhibitors/pharmacokinetics , Protease Inhibitors/therapeutic use , RatsABSTRACT
A novel series of TNF-alpha convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.
Subject(s)
ADAM Proteins/antagonists & inhibitors , ADAM Proteins/metabolism , Drug Discovery , Protease Inhibitors/chemistry , Tartrates/chemistry , Tumor Necrosis Factor-alpha/metabolism , ADAM17 Protein , Binding Sites , Combinatorial Chemistry Techniques , Crystallography, X-Ray , Drug Discovery/methods , Humans , Protease Inhibitors/metabolism , Protease Inhibitors/pharmacology , Tartrates/metabolism , Tartrates/pharmacologyABSTRACT
We disclose inhibitors of TNF-alpha converting enzyme (TACE) designed around a hydantoin zinc binding moiety. Crystal structures of inhibitors bound to TACE revealed monodentate coordination of the hydantoin to the zinc. SAR, X-ray, and modeling designs are described. To our knowledge, these are the first reported X-ray structures of TACE with a hydantoin zinc ligand.
Subject(s)
ADAM Proteins/antagonists & inhibitors , Drug Discovery , Enzyme Inhibitors/pharmacology , Hydantoins/pharmacology , ADAM17 Protein , Enzyme Inhibitors/chemistry , Hydantoins/chemistry , Hydrogen Bonding , Models, Molecular , Structure-Activity Relationship , X-Ray DiffractionABSTRACT
A series of potent and selective 3,4-diamino-1,2,5-thiadiazoles were prepared and found to show excellent binding affinities towards CXCR2 receptor.