Discovery of the potent non-steroidal glucocorticoid receptor modulator BAY 1003803 as clinical candidate

We report on the discovery of the new clinical candidate BAY 1003803 as glucocorticoid receptor agonist for the topical treatment of psoriasis or severe atopic dermatitis. In the course of optimizing the amino alcohol series as a highly potent new non-steroidal lead structure, considerations were made as to how physicochemical properties and safety concerns relate to structural motifs. BAY 1003803 demonstrates strong anti-inflammatory activity in vitro paired with a pharmacokinetic profile suitable for topical application.     

Heterocyclic glucocorticoid receptor modulators with a 2,2-dimethyl-3-phenyl-N-(thiazol or thiadiazol-2-yl)propanamide core

A series of heterocyclic glucocorticoid receptor (GR) modulators with 2,2-dimethyl-3-phenyl-N-(thiazol or thiadiazol-2-yl)propanamide core are described. Structure–activity relationships suggest a combination of H-bond acceptor and a 4-fluorophenyl moiety as being important structural components contributing to the glucocorticoid receptor binding and functional activity for this series of GR modulators.     

Discovery of orally available tetrahydroquinoline-based glucocorticoid receptor agonists

A series of tetrahydroquinoline derivatives were synthesized and profiled for their ability to act as glucocorticoid receptor selective modulators. Structure-activity relationships of the tetrahydroquinoline B-ring lead to the discovery of orally available GR-selective agonists with high in vivo activity.     

Discovery and SAR study of novel dihydroquinoline-containing glucocorticoid receptor agonists

We have recently reported the discovery of a novel class of glucocorticoid receptor (GR) antagonists, exemplified by 3, containing a 1,2-dihydroquinoline molecular scaffold. Further SAR studies of these antagonists uncovered chemical modifications conveying agonist functional activity to this series. These agonists exhibit good GR binding affinity and are selective against other nuclear hormone receptors.     

Nonsteroidal 2,3-dihydroquinoline glucocorticoid receptor agonists with reduced PEPCK activation

Continuing studies based on dihydroquinoline glucocorticoid receptor agonists lead to the discovery of a series of C4-oxime analogs. Representative compounds exhibited potent transrepression activity with minimal transactivation of phosphoenolpyruvate caboxykinase (PEPCK), a key protein in the gluconeogenesis pathway. These compounds represent promising leads in identifying GR agonists with high anti-inflammatory activity and attenuated potential for glucose elevation.     

Paired Hormone Response Elements Predict Caveolin-1 as a Glucocorticoid Target Gene

Glucocorticoids act in part via glucocortocoid receptor binding to hormone response elements (HREs), but their direct target genes in vivo are still largely unknown. We developed the criterion that genomic occurrence of paired HREs at an inter-HRE distance less than 200 bp predicts hormone responsiveness, based on synergy of multiple HREs, and HRE information from known target genes. This criterion predicts a substantial number of novel responsive genes, when applied to genomic regions 10 kb upstream of genes. Multiple-tissue in situ hybridization showed that mRNA expression of 6 out of 10 selected genes was induced in a tissue-specific manner in mice treated with a single dose of corticosterone, with the spleen being the most responsive organ. Caveolin-1 was strongly responsive in several organs, and the HRE pair in its upstream region showed increased occupancy by glucocorticoid receptor in response to corticosterone. Our approach allowed for discovery of novel tissue specific glucocorticoid target genes, which may exemplify responses underlying the permissive actions of glucocorticoids.     

Characterization and immunocytochemical demonstration of glucocorticoid receptor using antisera specific to transformed receptor

Cytosolic and nuclear forms of the glucocorticoid receptor were characterized using immunochemical techniques. Antibodies were raised in rabbits to an M_r 58,000 fragment of the transformed (DNA-binding) glucocorticoid receptor purified from rat liver cytosol by DNA-cellulose chromatography and polyacrylamide gel electrophoresis. Antibodies reacted with the transformed receptor form in a radioimmunoassay for glucocorticoid receptor. Western blot analysis of antibody reactivity revealed a single M_r 185,000 receptor form in rat liver cytosol but a smaller M_r 85,000 form in nucleosol, indicating the M_r 85,000 form is the transformed receptor. Furthermore, western blot analysis indicates that the M_r 185,000 receptor undergoes proteolysis during receptor purification and in vitro transformation processes by generating immunochemically similar proteins of smaller molecular weights. An identical M_r 185,000 glucocorticoid receptor was detected in cytosols of four rat tissues; liver, brain, adrenal medulla, and thymus. The glucocorticoid receptor was localized to the cytoplasm and nucleus of rat adrenal medulla cells by immunohistochemistry, demonstrating the existence in vivo of the transformed receptor and translocation of the receptor from cytoplasm to nucleus.     

Discovery of a potent series of non-steroidal non α-trifluoromethyl carbinol glucocorticoid receptor agonists with reduced lipophilicity

A novel series of indazole non-steroidal glucocorticoid receptor agonist has been discovered. This series features a sulfonamide central core and meta amides which interact with the extended ligand binding domain. This series has produced some of the most potent and least lipophilic agonists of which we are aware such as 20a (NFκB pIC₅₀ 8.3 (100%), c log P 1.9). Certain analogues in this series also display evidence for modulated pharmacology.     

The discovery of potent and selective non-steroidal glucocorticoid receptor modulators,suitable for inhalation

We report the discovery of highly potent and selective non-steroidal glucocorticoid receptor modulators with PK properties suitable for inhalation. A high throughput screen of the AstraZeneca compound collection identified sulfonamide 3 as a potent non-steroidal glucocorticoid receptor ligand. Further optimization of this lead generated indazoles 30 and 48 that were progressed to characterization in in vivo models. X-ray crystallography was used to gain further insight into the binding mode of selected ligands.     

The effect of pKa on pyrimidine/pyridine-derived histamine H4 ligands

During the course of our efforts toward the discovery of human histamine H₄ antagonists from a series of 2-aminiopyrimidines, it was noted that a 6-trifluoromethyl group dramatically reduced affinity of the series toward the histamine H₄ receptor. This observation was further investigated by synthesizing a series of ligands that varied in pK_a of the pyrimidine derived H₄ ligands by over five orders of magnitude and the effect on histamine H₄ affinity. This trend was then extended to the discovery of C-linked piperidinyl-2-amino pyridines as histamine H₄ receptor antagonists.     

Discovery of N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenol and -phenyl carboxamide series of μ-opioid receptor antagonists

Gastrointestinal dysfunction as a consequence of the use of opioid analgesics is of significant clinical concern. First generation drugs to treat these opioid-induced side-effects were limited by their negative impact on opioid receptor agonist-induced analgesia. Second generation therapies target a localized, peripherally-restricted, non-CNS penetrant drug distribution of opioid receptor antagonists. Herein we describe the discovery of the N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenol and -phenyl carboxamide series of μ-opioid receptor antagonists. This report highlights the discovery of the key μ-opioid receptor antagonist pharmacophore and the optimization of in vitro metabolic stability through the application of a phenol bioisostere. The compounds 27a and 31a with the most attractive in vitro profile, formed the basis for the application of Theravance Biopharma’s multivalent approach to drug discovery to afford the clinical compound axelopran (TD-1211), targeted for the treatment of opioid-induced constipation.     

Synthesis and in vitro biological evaluation of new pyrimidines as glucagon-like peptide-1 receptor agonists

The therapeutic success of peptide glucagon-like peptide-1 (GLP-1) receptor agonists for the treatment of type 2 diabetes mellitus has inspired discovery efforts aimed at developing orally available small-molecule GLP-1 receptor agonists. In this study, two series of new pyrimidine derivatives were designed and synthesized using an efficient route, and were evaluated in terms of GLP-1 receptor agonist activity. In the first series, novel pyrimidines substituted at positions 2 and 4 with groups varying in size and electronic properties were synthesized in a good yield (78–90%). In the second series, the designed pyrimidine templates included both urea and Schiff base linkers, and these compounds were successfully produced with yields of 77–84%. In vitro experiments with cultured cells showed that compounds 3a and 10a (10^?15–10^?9 M) significantly increased insulin secretion compared to that of the control cells in both the absence and presence of 2.8 mM glucose; compound 8b only demonstrated significance in the absence of glucose. These findings represent a valuable starting point for the design and discovery of small-molecule GLP-1 receptor agonists that can be administered orally.     

Human receptor kinetics and lung tissue retention of the enhanced-affinity glucocorticoid fluticasone furoate

Fluticasone furoate (FF) – USAN approved name, a new topically active glucocorticoid has been recently identified. The aim of this study was to characterise the binding affinity of this compound to the human lung glucocorticoid receptor in relation to other glucocorticoids. Additionally, we sought to determine the binding behaviour of fluticasone furoate to human lung tissue. The glucocorticoid receptor binding kinetics of fluticasone furoate revealed a remarkably fast association and a slow dissociation resulting in a relative receptor affinity (RRA) of 2989 ± 135 with reference to dexamethasone (RRA: 100 ± 5). Thus, the RRA of FF exceeds the RRAs of all currently clinically used corticosteroids such as mometasone furoate (MF; RRA 2244), fluticasone propionate (FP; RRA 1775), ciclesonide's active metabolite (RRA 1212 – rat receptor data) or budesonide (RRA 855). FP and FF displayed pronounced retention in human lung tissue in vitro. Lowest tissue binding was found for MF. There was no indication of instability or chemical modification of FF in human lung tissue. These advantageous binding attributes may contribute to a highly efficacious profile for FF as a topical treatment for inflammatory disorders of the respiratory tract.     

The glucocorticoid receptor in the distal nephron is not necessary for the development or maintenance of dexamethasone-induced hypertension

Glucocorticoids are used as a treatment for a variety of conditions and hypertension is a well-recognized side effect of their use. The mechanism of glucocorticoid-induced hypertension is incompletely understood and has traditionally been attributed to promiscuous activation of the mineralocorticoid receptor by cortisol. Multiple lines of evidence, however, point to the glucocorticoid receptor as an important mediator as well. We have developed a mouse model of glucocorticoid-induced hypertension, which is dependent on the glucocorticoid receptor. To determine the site(s) of glucocorticoid receptor action relevant to the development of hypertension, we studied glucocorticoid-induced hypertension in a mouse with a tissue-specific knockout of the glucocorticoid receptor in the distal nephron. Although knockout mice had similar body weight, nephron number and renal histology compared to littermate controls, their baseline blood pressure was mildly elevated. Nevertheless, distal nephron glucocorticoid receptor knockout mice and controls had a similar hypertensive response to dexamethasone. Urinary excretion of electrolytes, both before and after administration of glucocorticoid was also indistinguishable between the two groups. We conclude that the glucocorticoid receptor in the distal nephron is not necessary for the development or maintenance of dexamethasone-induced hypertension in our model.     

Optimization of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepine-5-ylidene)acetamide derivatives as arginine vasopressin V2 receptor agonists and discussion of their binding modes

A series of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepine-5-ylidene)acetamide derivatives were optimized to achieve potent agonistic activity, both in vitro and in vivo, for the arginine vasopressin V₂ receptor, resulting in the eventual discovery of compound 1g. Molecular modeling of compound 1g with V₂ receptor was also examined to evaluate the binding mode of this series of compounds.     

Dual acting norepinephrine reuptake inhibitors and 5-HT2A receptor antagonists: Identification,synthesis and activity of novel 4-aminoethyl-3-(phenylsulfonyl)-1H-indoles

The discovery of a series of 4-aminoethyl-3-(phenylsulfonyl)-1H-indoles, dual acting norepinephrine reuptake inhibitors (NRIs) and 5-HT_2A receptor antagonists, is described. The synthesis and structure–activity relationship (SAR) of this novel series of compounds is also presented.     

Discovery of a potent and dissociated non-steroidal glucocorticoid receptor agonist containing an alkyl carbinol pharmacophore

Synthesis and structure–activity relationship (SAR) of a series of alkyl and cycloalkyl containing non-steroidal dissociated glucocorticoid receptor (GR) agonists is reported. This series of compounds was identified as part of an effort to replace the CF₃ group in a scaffold represented by 1a. The study culminated in the identification of compound 14, a t-butyl containing derivative, which has shown potent activity for GR, selectivity against the progesterone receptor (PR) and the mineralocorticoid receptor (MR), in vitro anti-inflammatory activity in an IL-6 transrepression assay, and dissociation in a MMTV transactivation counter-screen. In a collagen-induced arthritis mouse model, 14 displayed prednisolone-like efficacy, and lower impact on body fat and free fatty acids than prednisolone at an equivalent anti-inflammatory dose.     

Discovery of furan-2-carbohydrazides as orally active glucagon receptor antagonists

Furan-2-carbohydrazides were found as orally active glucagon receptor antagonists. Starting from the hit compound 5, we successfully determined the structure activity relationships of a series of derivatives obtained by modifying the acidity of the phenol. We identified the ortho-nitrophenol as a good scaffold for glucagon receptor inhibitory activity. Our efforts have led to the discovery of compound 7l as a potent glucagon receptor antagonist with good bioavailability and satisfactory long half-life.