Zice Fu

Optimization of a series of quinazolinone-derived antagonists of CXCR3.

The evaluation of the CXCR3 antagonist AMG 487 in clinic trials was complicated due to the formation of an active metabolite. In this Letter, we will discuss the further optimization of the quinazolinone series that led to the discovery of compounds devoid of the formation of the active metabolite that was seen with AMG 487. In addition, these compounds also feature increased potency and good pharmacokinetic properties. We will also discuss the efficacy of the lead compound 34 in a mouse model of cellular recruitment induced by bleomycin.

Discovery and optimization of CRTH2 and DP dual antagonists

A series of phenylacetic acid derivatives was discovered as CRTH2 antagonists. Modification of the series led to compounds that are also antagonists of DP. Since activation of CRTH2 and DP are believed to play key roles in mediating responses of asthma and other immune diseases, this series was optimized to increase the dual antagonistic activities and improve pharmacokinetic properties. These efforts led to selection of AMG 009 as a clinical candidate.

Potent and Orally Bioavailable GPR142 Agonists as Novel Insulin Secretagogues for the Treatment of Type 2 Diabetes

GPR142 is a G protein-coupled receptor that is predominantly expressed in pancreatic β-cells. GPR142 agonists stimulate insulin secretion in the presence of high glucose concentration, so that they could be novel insulin secretagogues with reduced or no risk of hypoglycemia. We report here the optimization of HTS hit compound 1 toward a proof of concept compound 33, which showed potent glucose lowering effects during an oral glucose tolerance test in mice and monkeys.

Discovery of AMG 853, a CRTH2 and DP Dual Antagonist.

Prostaglandin D2 (PGD2) plays a key role in mediating allergic reactions seen in asthma, allergic rhinitis, and atopic dermatitis. PGD2 exerts its activity through two G protein-coupled receptors (GPCRs), prostanoid D receptor (DP or DP1), and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2 or DP2). We report the optimization of a series of phenylacetic acid derivatives in an effort to improve the dual activity of AMG 009 against DP and CRTH2. These efforts led to the discovery of AMG 853 (2-(4-(4-(tert-butylcarbamoyl)-2-(2-chloro-4-cyclopropylphenyl sulfonamido)phenoxy)-5-chloro-2-fluorophenyl)acetic acid), which is being evaluated in human clinical trials for asthma.

Phenylalanine derivatives as GPR142 agonists for the treatment of type II diabetes.

GPR142 is a novel GPCR that is predominantly expressed in pancreatic β-cells. GPR142 agonists potentiate glucose-dependent insulin secretion, and therefore can reduce the risk of hypoglycemia. Optimization of our lead pyridinone-phenylalanine series led to a proof-of-concept compound 22, which showed in vivo efficacy in mice with dose-dependent increase in insulin secretion and a decrease in glucose levels.

Aminopyrazole-Phenylalanine Based GPR142 Agonists: Discovery of Tool Compound and in Vivo Efficacy Studies.

Herein, we report the lead optimization of amrinone-phenylalanine based GPR142 agonists. Structure-activity relationship studies led to the discovery of aminopyrazole-phenylalanine carboxylic acid 22, which exhibited good agonistic activity, high target selectivity, desirable pharmacokinetic properties, and no cytochrome P450 or hERG liability. Compound 22, together with its orally bioavailable ethyl ester prodrug 23, were found to be suitable for in vivo proof-of-concept studies. Compound 23 displayed good efficacy in a mouse oral glucose tolerance test (OGTT). Compound 22 showed GPR142 dependent stimulation of insulin secretion in isolated mouse islets and demonstrated a statistically significant glucose lowering effect in a mouse model bearing transplanted human islets.

Discovery of potent and specific CXCR3 antagonists.

The optimization of a series of 8-aza-quinazolinone analogs for antagonist activity against the CXCR3 receptor is reported. Compounds were optimized to avoid the formation of active metabolites and time-dependent-inhibitors of CYP3A4. In addition, antagonists showed potent against CXCR3 activity in whole blood and optimized to avoid activity in the chromosomal aberration assay. Compound 25 was identified as having the optimal balance of CXCR3 activity and pharmacokinetic properties across multiple pre-clinical species, which are reported herein.

C5-Alkyl-2-methylurea-Substituted Pyridines as a New Class of Glucokinase Activators

Glucokinase (GK) activators represent a class of type 2 diabetes therapeutics actively pursued due to the central role that GK plays in regulating glucose homeostasis. Herein we report a novel C5-alkyl-2-methylurea-substituted pyridine series of GK activators derived from our previously reported thiazolylamino pyridine series. Our efforts in optimizing potency, enzyme kinetic properties, and metabolic stability led to the identification of compound 26 (AM-9514). This analogue showed a favorable combination of in vitro potency, enzyme kinetic properties, acceptable pharmacokinetic profiles in preclinical species, and robust efficacy in a rodent PD model.

Novel Series of Potent Glucokinase Activators Leading to the Discovery of AM-2394

Glucokinase (GK) catalyzes the phosphorylation of glucose to glucose-6-phosphate. We present the structure-activity relationships leading to the discovery of AM-2394, a structurally distinct GKA. AM-2394 activates GK with an EC50 of 60 nM, increases the affinity of GK for glucose by approximately 10-fold, exhibits moderate clearance and good oral bioavailability in multiple animal models, and lowers glucose excursion following an oral glucose tolerance test in an ob/ob mouse model of diabetes.

Optimization of phenylacetic acid derivatives for CRTH2 and DP selective antagonism.

We have previously reported that optimization of a series of phenylacetic acid derivatives led to the discovery of CRTH2 and DP dual antagonists, such as AMG 009 and AMG 853. During the optimization process, we discovered that minor structural modifications also afforded potent and selective CRTH2 or DP antagonists. Here we report the structure-activity relationship that led to the discovery of selective CRTH2 antagonists such as 2 and 17, and selective DP antagonists, such as 4 and 5.