Carboxylated, heteroaryl-substituted chalcones as inhibitors of vascular cell adhesion molecule-1 expression for use in chronic inflammatory diseases.

Starting from a simple chalcone template, structure-activity relationship (SAR) studies led to a series of carboxylated, heteroaryl-substituted chalcone derivatives as novel, potent inhibitors of vascular cell adhesion molecule-1 (VCAM-1) expression. Correlations between lipophilicity determined by calculated logP values and inhibitory efficacy were observed among structurally similar compounds of the series. Various substituents were found to be tolerated at several positions of the chalcone backbone as long as the compounds fell into the right range of lipophilicity. The chalcone alpha,beta-unsaturated ketone moiety seemed to be the pharmacophore required for inhibition of VCAM-1 expression. Compound 19 showed significant antiinflammatory effects in a mouse model of allergic inflammation, indicating that this series of compounds might have therapeutic value for human asthma and other inflammatory disorders.

Atherosclerosis is an inflammatory disorder after all.

Inflammation has been increasingly recognized as an important player in the pathophysiology of numerous human disorders. Accumulating evidence has led to the conclusion that atherosclerosis is an inflammatory disease, although it was believed to be a disorder of high cholesterol levels in the bloodstream for over a century. Cholesterol does contribute to the pathogenesis of atherosclerosis, but through inflammatory mechanisms. Statins lower cholesterol levels and hence reduce inflammation in the vasculature and prevent heart disease. Statins may also exert anti-inflammatory effects through mechanisms independent of cholesterol lowering. Adhesion molecules, cytokines, oxidative stress, etc. appear to contribute to the inflammatory state of atherosclerosis and therapeutic approaches directed toward these markers or targets have the potential to be effective in reducing inflammation and treating atherosclerosis.

AGIX-4207 [2-[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenoxy]acetic acid], a novel antioxidant and anti-inflammatory compound: cellular and biochemical characterization of antioxidant activity and inhibition of redox-sensitive inflammatory gene expression.

The pathogenesis of chronic inflammatory diseases, including rheumatoid arthritis, is regulated, at least in part, by modulation of oxidation-reduction (redox) homeostasis and the expression of redox-sensitive inflammatory genes including adhesion molecules, chemokines, and cytokines. AGIX-4207 [2-[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenoxy]acetic acid] is a novel, orally active, phenolic antioxidant and anti-inflammatory compound with antirheumatic properties. To elucidate its anti-inflammatory mechanisms, we evaluated AGIX-4207 for a variety of cellular, biochemical, and molecular properties. AGIX-4207 exhibited potent antioxidant activity toward lipid peroxides in vitro and displayed enhanced cellular uptake relative to a structurally related drug, probucol. This resulted in potent inhibition of cellular levels of reactive oxygen species in multiple cell types. AGIX-4207 selectively inhibited tumor necrosis factor (TNF)-alpha-inducible levels of the redox-sensitive genes, vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, with less inhibition of E-selectin, and no effect on intracellular adhesion molecule-1 expression in endothelial cells. In addition, AGIX-4207 inhibited cytokine-induced levels of monocyte chemoattractant protein-1, interleukin (IL)-6, and IL-8 from endothelial cells and human fibroblast-like synoviocytes as well as lipopolysaccharide-induced release of TNF-alpha, IL-1beta, and IL-6 from human peripheral blood mononuclear cells. AGIX-4207 did not inhibit TNF-alpha-induced nuclear translocation of nuclear factor of the kappa-enhancer in B cells (NF-kappaB), suggesting that the mechanism of action is independent of this redox-sensitive transcription factor. Taken together, these results provide a mechanistic framework for understanding the anti-inflammatory and antirheumatic activity of AGIX-4207 and provide further support for the view that inhibition of redox-sensitive inflammatory gene expression is an attractive approach for the treatment of chronic inflammatory diseases.

Inflammation in atherosclerosis: new opportunities for drug discovery.

Many lines of evidence indicate that inflammation is the ultimate cause of atherosclerosis; high cholesterol levels cause atherosclerosis through mechanism of inflammation. Drugs designed to address inflammatory aspects of atherosclerosis will likely be more effective than current therapies in treating and preventing coronary artery disease.

Discovery of novel phenolic antioxidants as inhibitors of vascular cell adhesion molecule-1 expression for use in chronic inflammatory diseases.

Vascular cell adhesion molecule-1 (VCAM-1) mediates recruitment of leukocytes to endothelial cells and is implicated in many inflammatory conditions. Since part of the signal transduction pathway that regulates the activation of VCAM-1 expression is redox-sensitive, compounds with antioxidant properties may have inhibitory effects on VCAM-1 expression. Novel phenolic compounds have been designed and synthesized starting from probucol (1). Many of these compounds demonstrated potent inhibitory effects on cytokine-induced VCAM-1 expression and displayed potent antioxidant effects in vitro. Some of these derivatives (4o, 4p, 4w, and 4x) inhibited lipopolysaccharide (LPS)-induced secretion of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-6 from human peripheral blood mononuclear cells (hPBMCs) in a concentration-dependent manner in vitro and showed antiinflammatory effects in an animal model. Compounds 4ad and 4ae are currently in clinical trials for the treatment of rheumatoid arthritis (RA) and prevention of chronic organ transplant rejection, respectively.

Discovery of novel heteroaryl-substituted chalcones as inhibitors of TNF-alpha-induced VCAM-1 expression.

Novel chalcone derivatives have been discovered as potent inhibitors of TNF-alpha-induced VCAM-1 expression. Thienyl or benzothienyl substitution at the meta-position of ring B helps boost potency while large substitution at the para-position on ring B is detrimental. Various substitutions are tolerated on ring A. A lipophilicity-potency relationship has been observed in several sub-series of compounds.

BO-653. Chugai.

BO-653 is an antioxidant under development by Chugai for the potential treatment of atherosclerosis and the prevention of restenosis. By November 2001, BO-653 was in phase II trials for restenosis in post-percutaneous transluminal coronary angioplasty in the US, and by April 2002, the compound was in phase I trials for the same indication in Japan.

AGI-1067: a multifunctional phenolic antioxidant, lipid modulator, anti-inflammatory and antiatherosclerotic agent.

To explore the therapeutic efficacy and potential mechanisms of action of a new class of antiatherosclerotic drugs, AGI-1067 [mono[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenyl] ester] (butanedioc acid) was tested in several animal models of atherosclerosis. AGI-1067, a novel phenolic antioxidant, was well tolerated in a 1-year study in hypercholesterolemic cynomolgus monkeys. It lowered low-density lipoprotein cholesterol (LDLc) by 41 and 90% at oral doses of 50 and 150 mg/kg, respectively and increased high-density lipoprotein cholesterol (HDLc) by 107% at the higher dose. In contrast, another phenolic antioxidant, probucol, had a modest LDLc-lowering effect (15% at 250 mg/kg) while decreasing HDLc (37% at 150 mg/kg). Histopathology of the aortas and coronary arteries revealed no atherosclerosis in the AGI-1067 (150 mg/kg) group and minimal-to-moderate atherosclerosis in the vehicle and probucol (150 mg/kg) groups. AGI-1067 also inhibited atherosclerosis in LDL receptor-deficient (LDLr -/-) mice and apolipoprotein E-deficient (ApoE -/-) mice even in the absence of a lipid-lowering effect. In LDLr -/- mice, AGI-1067 reduced aortic atherosclerosis by 49%. In ApoE -/- mice, AGI-1067 reduced atherosclerosis by 25, 41, and 49% in the arch, thoracic, and abdominal regions of the aorta. AGI-1067 also reduced vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) mRNA levels in lungs of lipopolysaccharide-stimulated mice. At the cellular level, AGI-1067 inhibited tumor necrosis factor-alpha-inducible expression of VCAM-1, MCP-1, and E-selectin in human aortic endothelial cells (IC50 values = 6, 10, and 25 microM, respectively). These data show that AGI-1067 can inhibit atherosclerosis not only via its lipid-lowering effects but also by having direct anti-inflammatory effects on the vessel wall and suggest that it may be a novel therapeutic agent for coronary artery disease.

Lead discovery of alpha,beta-unsaturated sulfones from a combinatorial library as inhibitors of inducible VCAM-1 expression.

alpha,beta-Unsaturated sulfones have been discovered from a combinatorial library as leads for a new series of inhibitors of inducible VCAM-1 expression. Although not essential, further conjugation of the sulfonyl group to another vinyl group or a phenyl group increases the potency dramatically.

Chemistry and pharmacology of vascular protectants: a novel approach to the treatment of atherosclerosis and coronary artery disease.

This review addresses the role of oxidative stress in the pathology of atherosclerosis and why it is now believed that atherosclerosis is not only a disease of oxidative stress but also of chronic inflammation. Perhaps more importantly, this review also describes the vascular protectant (V-protectant) technology platform originated at AtheroGenics, Inc., from which a series of inhibitory compounds has emerged to treat a number of chronic inflammatory diseases, including atherosclerosis. In atherosclerosis, these drugs not only act as antioxidants, but also as lipid modulators, inhibitors of inflammation, and inhibitors of gene expression. It is also important to understand the basis for considering vascular cell adhesion molecule-1 (VCAM-1) as a reduction-oxidation-sensitive protein, which has a key role in the early phases of atherosclerosis. The review concludes with a description of the design and chemistry of AtheroGenics' lead clinical development compound, AGI-1067, and an analysis of its preclinical in vitro and in vivo profile. AGI-1067 is a novel, potent antioxidant with anti-inflammatory properties. It inhibits gene expression of VCAM-1 and monocyte chemoattractant protein-1, decreases low-density lipoprotein cholesterol levels, and prevents atherosclerosis in a number of animal models. AGI-1067 is currently undergoing clinical trials as an antiatherosclerotic agent.

Novel phenolic antioxidants as multifunctional inhibitors of inducible VCAM-1 expression for use in atherosclerosis.

A series of novel phenolic compounds has been discovered as potent inhibitors of TNF-alpha-inducible expression of vascular cell adhesion molecule-1 (VCAM-1) with concurrent antioxidant and lipid-modulating properties. Optimization of these multifunctional agents led to the identification of 3a (AGI-1067) as a clinical candidate with demonstrated efficacies in animal models of atherosclerosis and hyperlipidemia.

Ezetimibe. Schering-Plough.

Ezetimibe (Sch-58235) is a cholesterol absorption inhibitor under development by Schering-Plough (SP), in collaboration with Merck, for the potential treatment of hypercholesterolemia. In late December 2001, the companies filed an NDA in the US for this indication. SP is studying ezetimibe as a monotherapy for lowering lipid levels, and also in combination with commonly used statins therapies. The company believes that ezetimibe will have additive effects with the statins, inhibiting the absorption of cholesterol in the intestine, while the statins work by inhibiting the production of cholesterol in the liver. In May 2000, SP and Merck signed an agreementfor the codevelopment of ezetimibe covering its uses as a monotherapy, in combination with statins, and as a fixed combination with simvastatin. In December 2001, Merck and SP expanded their partnership launched in the US in 2000, to develop and market ezetimibe. In August and September 2001, Credit Suisse First Boston predicted ezetimibe sales of US $420 million in 2003 and US $959 million in 2004. Analysts at Salomon Smith Barney predicted in November 2001 that the product would be launched in 2003.