Discovery of Heteroaryl Urea Isosteres for Formyl Peptide Receptor 2 Agonists.

Formyl peptide receptor 2 (FPR2) agonists have shown efficacy in inflammatory-driven animal disease models and have the potential to treat a range of diseases. Many reported synthetic agonists contain a phenylurea, which appears to be necessary for activity in the reported chemotypes. We set out to find isosteres for the phenylurea and focused our efforts on heteroaryl rings. The wide range of potencies with heterocyclic isosteres demonstrates how electronic effects of the heteroatom placement impact molecular recognition. Herein, we report our discovery of benzimidazole and aminophenyloxadiazole FPR2 agonists with low nanomolar activity.

Formyl peptide receptor 2 and heart disease.

Formyl peptide receptor type 2 (FPR2) regulates the initiation and resolution phases of the inflammatory response. In the setting of heart injury and disease, dysregulated inflammation can potentiate maladaptive healing and pathological remodeling of the heart leading to cardiac dysfunction and failure. The potential to regulate and resolve adverse inflammation is postulated to improve outcome in the setting of heart disease. This review covers emerging concepts on the role of FPR2 in heart disease and strategies to activate pro-resolution processes to limit disease progression. We summarize key preclinical studies that support use of FPR2 agonists in heart disease. Finally, we briefly discuss the status of FPR2 agonists under evaluation in the clinic.

Selective FPR2 Agonism Promotes a Proresolution Macrophage Phenotype and Improves Cardiac Structure-Function Post Myocardial Infarction.

Dysregulated inflammation following myocardial infarction (MI) leads to maladaptive healing and remodeling. The study characterized and evaluated a selective formyl peptide receptor 2 (FPR2) agonist BMS-986235 in cellular assays and in rodents undergoing MI. BMS-986235 activated G proteins and promoted ß-arrestin recruitment, enhanced phagocytosis and neutrophil apoptosis, regulated chemotaxis, and stimulated interleukin-10 and monocyte chemoattractant protein-1 gene expression. Treatment with BMS-986235 improved mouse survival, reduced left ventricular area, reduced scar area, and preserved wall thickness. Treatment increased macrophage arginase-1 messenger RNA and CD206 receptor levels indicating a proresolution phenotype. In rats following MI, BMS-986235 preserved viable myocardium, attenuated left ventricular remodeling, and increased ejection fraction relative to control animals. Therefore, FPR2 agonism improves post-MI healing, limits remodeling and preserves function, and may offer an innovative therapeutic option to improve outcomes.

Preservation of Post-Infarction Cardiac Structure and Function via Long-Term Oral Formyl Peptide Receptor Agonist Treatment.

Dysregulated inflammation following myocardial infarction (MI) promotes left ventricular (LV) remodeling and loss of function. Targeting inflammation resolution by activating formyl peptide receptors (FPRs) may limit adverse remodeling and progression towards heart failure. This study characterized the cellular and signaling properties of Compound 43 (Cmpd43), a dual FPR1/FPR2 agonist, and examined whether Cmpd43 treatment improves LV and infarct remodeling in rodent MI models. Cmpd43 stimulated FPR1/2-mediated signaling, enhanced proresolution cellular function, and modulated cytokines. Cmpd43 increased LV function and reduced chamber remodeling while increasing proresolution macrophage markers. The findings demonstrate that FPR agonism improves cardiac structure and function post-MI.

11ß-hydroxysteroid dehydrogenase type 1 gene knockout attenuates atherosclerosis and in vivo foam cell formation in hyperlipidemic apoE⁻/⁻ mice.

BACKGROUND: Chronic glucocorticoid excess has been linked to increased atherosclerosis and general cardiovascular risk in humans. The enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) increases active glucocorticoid levels within tissues by catalyzing the conversion of cortisone to cortisol. Pharmacological inhibition of 11ßHSD1 has been shown to reduce atherosclerosis in murine models. However, the cellular and molecular details for this effect have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: To examine the role of 11ßHSD1 in atherogenesis, 11ßHSD1 knockout mice were created on the pro-atherogenic apoE⁻/⁻ background. Following 14 weeks of Western diet, aortic cholesterol levels were reduced 50% in 11ßHSD1⁻/⁻/apoE⁻/⁻ mice vs. 11ßHSD1⁺/⁺/apoE⁻/⁻ mice without changes in plasma cholesterol. Aortic 7-ketocholesterol content was reduced 40% in 11ßHSD1⁻/⁻/apoE⁻/⁻ mice vs. control. In the aortic root, plaque size, necrotic core area and macrophage content were reduced ∼30% in 11ßHSD1⁻/⁻/apoE⁻/⁻mice. Bone marrow transplantation from 11ßHSD1⁻/⁻/apoE⁻/⁻ mice into apoE⁻/⁻ recipients reduced plaque area 39-46% in the thoracic aorta. In vivo foam cell formation was evaluated in thioglycollate-elicited peritoneal macrophages from 11ßHSD1⁺/⁺/apoE⁻/⁻ and 11ßHSD1⁻/⁻/apoE⁻/⁻ mice fed a Western diet for ∼5 weeks. Foam cell cholesterol levels were reduced 48% in 11ßHSD1⁻/⁻/apoE⁻/⁻ mice vs. control. Microarray profiling of peritoneal macrophages revealed differential expression of genes involved in inflammation, stress response and energy metabolism. Several toll-like receptors (TLRs) were downregulated in 11ßHSD1⁻/⁻/apoE⁻/⁻ mice including TLR 1, 3 and 4. Cytokine release from 11ßHSD1⁻/⁻/apoE⁻/⁻-derived peritoneal foam cells was attenuated following challenge with oxidized LDL. CONCLUSIONS: These findings suggest that 11ßHSD1 inhibition may have the potential to limit plaque development at the vessel wall and regulate foam cell formation independent of changes in plasma lipids. The diminished cytokine response to oxidized LDL stimulation is consistent with the reduction in TLR expression and suggests involvement of 11ßHSD1 in modulating binding of pro-atherogenic TLR ligands.

N-aryl-oxazolidin-2-imine muscle selective androgen receptor modulators enhance potency through pharmacophore reorientation.

A novel selective androgen receptor modulator (SARM) scaffold was discovered as a byproduct obtained during synthesis of our earlier series of imidazolidin-2-ones. The resulting oxazolidin-2-imines are among the most potent SARMs known, with many analogues exhibiting sub-nM in vitro potency in binding and functional assays. Despite the potential for hydrolytic instability at gut pH, compounds of the present class showed good oral bioavailability and were highly active in a standard rodent pharmacological model.

Tandem optimization of target activity and elimination of mutagenic potential in a potent series of N-aryl bicyclic hydantoin-based selective androgen receptor modulators.

Pharmacokinetic studies in cynomolgus monkeys with a novel prototype selective androgen receptor modulator revealed trace amounts of an aniline fragment released through hydrolytic metabolism. This aniline fragment was determined to be mutagenic in an Ames assay. Subsequent concurrent optimization for target activity and avoidance of mutagenicity led to the identification of a pharmacologically superior clinical candidate without mutagenic potential.

Pharmacological and x-ray structural characterization of a novel selective androgen receptor modulator: potent hyperanabolic stimulation of skeletal muscle with hypostimulation of prostate in rats.

A novel, highly potent, orally active, nonsteroidal tissue selective androgen receptor (AR) modulator (BMS-564929) has been identified, and this compound has been advanced to clinical trials for the treatment of age-related functional decline. BMS-564929 is a subnanomolar AR agonist in vitro, is highly selective for the AR vs. other steroid hormone receptors, and exhibits no significant interactions with SHBG or aromatase. Dose response studies in castrated male rats show that BMS-564929 is substantially more potent than testosterone (T) in stimulating the growth of the levator ani muscle, and unlike T, highly selective for muscle vs. prostate. Key differences in the binding interactions of BMS-564929 with the AR relative to the native hormones were revealed through x-ray crystallography, including several unique contacts located in specific helices of the ligand binding domain important for coregulatory protein recruitment. Results from additional pharmacological studies effectively exclude alternative mechanistic contributions to the observed tissue selectivity of this unique, orally active androgen. Because concerns regarding the potential hyperstimulatory effects on prostate and an inconvenient route of administration are major drawbacks that limit the clinical use of T, the potent oral activity and tissue selectivity exhibited by BMS-564929 are expected to yield a clinical profile that provides the demonstrated beneficial effects of T in muscle and other tissues with a more favorable safety window.

Discovery of potent, orally-active, and muscle-selective androgen receptor modulators based on an N-aryl-hydroxybicyclohydantoin scaffold.

A novel, N-aryl-bicyclohydantoin selective androgen receptor modulator scaffold was discovered through structure-guided modifications of androgen receptor antagonists. A prototype compound (7R,7aS)-10b from this series is a potent and highly tissue-selective agonist of the androgen receptor. After oral dosing in a rat atrophied levator ani muscle model, (7R,7aS)-10b demonstrated efficacy at restoring levator ani muscle mass to that of intact controls and exhibited >50-fold selectivity for muscle over prostate.

Inhibition of disease progression by a novel retinoid antagonist in animal models of arthritis.

OBJECTIVE: To investigate the usefulness of a novel retinoic acid receptor (RAR) antagonist (BMS-189453) in animal models of arthritis. METHODS: BMS-189453 was tested in HIG-82 rabbit synovial fibroblasts to determine its ability to repress collagenase (matrix metalloproteinase-1, MMP-1) mRNA expression in vitro. Cells were stimulated with phorbol myristate acetate or interleukin 1 beta and mRNA quantified by slot-blot analysis. In vivo, BMS-189453 was evaluated in 2 animal models of arthritis: collagen induced arthritis (CIA) in mice and streptococcal cell wall induced arthritis (SCWA) in rats. Clinical scores for arthritis were recorded weekly. At the end of each study, limbs were evaluated histologically. In CIA, these results were correlated with mRNA levels for collagenase-3 (MMP-13) and stromelysin-1 (MMP-3) as determined by Northern blot. RESULTS: BMS-189453 reduced MMP-1 expression in HIG-82 synovial fibroblasts in culture. BMS-189453 treatment blocked the clinical progression of arthritis beyond soft tissue inflammation in the CIA model. In the SCWA model, BMS-189453 treatment resulted in significantly reduced swelling with no notable progression to joint distortion/destruction. Histological evaluation of the joints from animals in both models confirmed this result. Analysis of mRNA from the CIA paws showed that BMS-189453 prevented the overexpression of MMP-13 and MMP-3 in arthritic joints. CONCLUSION: Improvement in clinical and histologic variables in 2 separate animal models, along with simultaneous reduction in MMP expression in the affected joint, suggests that RAR antagonists such as BMS-189453 may be useful as agents to treat rheumatoid arthritis and for determining the role of MMP in disease progression. This is the first study to show the clinical potential of RAR antagonists in arthritis.