Evaluation of antisense oligonucleotide therapy targeting Hsd17b13 in a fibrosis mice model.

Human genetic evidence suggests a protective role of loss-of-function variants in 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) for liver fibrotic diseases. Although there is limited preclinical experimental data on Hsd17b13 antisense oligonucleotide (ASO) or siRNA in a fibrosis model, several ASO and siRNA approaches are being tested clinically as potential therapies for nonalcoholic steatohepatitis (NASH). The aim of this study was to assess the therapeutic potential of Hsd17b13 ASO in a preclinical advanced NASH-like hepatic fibrosis in vivo model. In vitro testing on primary hepatocytes demonstrated that Hsd17b13 ASO exhibited strong efficacy and specificity for knockdown of the Hsd17b13 gene. In choline-deficient, L-amino acid-defined, HFD (CDAHFD)-induced steatotic and fibrotic mice, therapeutic administration of Hsd17b13 ASO resulted in a significant and dose-dependent reduction of hepatic Hsd17b13 gene expression. The CDAHFD group exhibited considerably elevated liver enzyme levels, hepatic steatosis score, hepatic fibrosis, and increased fibrotic and inflammatory gene expression, indicating an advanced NASH-like hepatic fibrosis phenotype. Although Hsd17b13 ASO therapy significantly affected hepatic steatosis, it had no effect on hepatic fibrosis. Our findings demonstrate, for the first time, that Hsd17b13 ASO effectively suppressed Hsd17b13 gene expression both in vitro and in vivo, and had a modulatory effect on hepatic steatosis in mice, but did not affect fibrosis in the CDAHFD mouse model of NASH.

Optimization of physicochemical properties of pyrrolidine GPR40 AgoPAMs results in a differentiated profile with improved pharmacokinetics and reduced off-target activities.

GPR40 AgoPAMs are highly effective antidiabetic agents that have a dual mechanism of action, stimulating both glucose-dependent insulin and GLP-1 secretion. The early lipophilic, aromatic pyrrolidine and dihydropyrazole GPR40 AgoPAMs from our laboratory were highly efficacious in lowering plasma glucose levels in rodents but possessed off-target activities and triggered rebound hyperglycemia in rats at high doses. A focus on increasing molecular complexity through saturation and chirality in combination with reducing polarity for the pyrrolidine AgoPAM chemotype resulted in the discovery of compound 46, which shows significantly reduced off-target activities as well as improved aqueous solubility, rapid absorption, and linear PK. In vivo, compound 46 significantly lowers plasma glucose levels in rats during an oral glucose challenge yet does not demonstrate the reactive hyperglycemia effect at high doses that was observed with earlier GPR40 AgoPAMs.

MGAT2 inhibitor decreases liver fibrosis and inflammation in murine NASH models and reduces body weight in human adults with obesity.

Monoacylglycerol acyltransferase 2 (MGAT2) is an important enzyme highly expressed in the human small intestine and liver for the regulation of triglyceride absorption and homeostasis. We report that treatment with BMS-963272, a potent and selective MGAT2 inhibitor, decreased inflammation and fibrosis in CDAHFD and STAM, two murine nonalcoholic steatohepatitis (NASH) models. In high-fat-diet-treated cynomolgus monkeys, in contrast to a selective diacylglycerol acyltransferase 1 (DGAT1) inhibitor, BMS-963272 did not cause diarrhea. In a Phase 1 multiple-dose trial of healthy human adults with obesity (NCT04116632), BMS-963272 was safe and well tolerated with no treatment discontinuations due to adverse events. Consistent with the findings in rodent models, BMS-963272 elevated plasma long-chain dicarboxylic acid, indicating robust pharmacodynamic biomarker modulation; increased gut hormones GLP-1 and PYY; and decreased body weight in human subjects. These data suggest MGAT2 inhibition is a promising therapeutic opportunity for NASH, a disease with high unmet medical needs.

Combined Therapy with a CCR2/CCR5 Antagonist and FGF21 Analogue Synergizes in Ameliorating Steatohepatitis and Fibrosis.

(1) Background: With new potential drug targets emerging, combination therapies appear attractive to treat non-alcoholic steatohepatitis (NASH) and fibrosis. Chemokine receptor CCR2/5 antagonists can improve fibrosis by reducing monocyte infiltration and altering hepatic macrophage subsets. Fibroblast growth factor 21 (FGF21) may improve NASH by modulating lipid and glucose metabolism. We compared effects of single drug to combination treatment as therapeutic strategies against NASH. (2) Methods: We analyzed serum samples and liver biopsies from 85 nonalcoholic fatty liver disease (NAFLD) patients. A CCR2/5 inhibitor (BMS-687681-02-020) and a pegylated FGF21 agonist (BMS-986171) were tested in male C57BL/6J mice subjected to dietary models of NASH and fibrosis (choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) up to 12 weeks; short- (2w) or long-term (6w) treatment). (3) Results: In NAFLD patients, chemokine CCL2 and FGF21 serum levels correlated with inflammatory serum markers, only CCL2 was significantly associated with advanced liver fibrosis. In rodent NASH, CCR2/5 inhibition significantly reduced circulating Ly6C+ monocytes and hepatic monocyte-derived macrophages, alongside reduced hepatic inflammation and fibrosis. FGF21 agonism decreased body weight, liver triglycerides and histological NASH activity. Combination treatment reflected aspects of both compounds upon short- and long-term application, thereby amplifying beneficial effects on all aspects of steatohepatitis and fibrosis. (4) Conclusions: CCR2/5 inhibition blocks hepatic infiltration of inflammatory monocytes, FGF21 agonism improves obesity-related metabolic disorders. Combined therapy ameliorates steatohepatitis and fibrosis more potently than single drug treatment in rodent NASH, corroborating the therapeutic potential of combining these two approaches in NASH patients.

Evaluation of a PEGylated Fibroblast Growth Factor 21 Variant Using Novel Preclinical Magnetic Resonance Imaging and Magnetic Resonance Elastography in a Mouse Model of Nonalcoholic Steatohepatitis.

BACKGROUND: Treatments for nonalcoholic steatohepatitis (NASH) are urgently needed. Hepatic fat fraction and shear stiffness quantified by magnetic resonance imaging (MRI-HFF) and magnetic resonance elastography (MRE-SS), respectively, are biomarkers for hepatic steatosis and fibrosis. PURPOSE: This study assessed the longitudinal effects of fibroblast growth factor 21 variant (polyethylene glycol [PEG]-FGF21v) on MRI-HFF and MRE-SS in a NASH mouse model. STUDY TYPE: Preclinical. ANIMAL MODEL: This study included a choline-deficient, amino acid-defined, high-fat diet (CDAHFD) model and 6-week-old, male C57BL/6J mice (N = 78). FIELD STRENGTH/SEQUENCE: This study was performed using: 3T: gradient-echo two-point Dixon and spin-echo (SE) echo-planar imaging elastography (200 Hz) and 7T: SE two-point Dixon and SE elastography (200 Hz). ASSESSMENT: MRI and MRE were performed before control diet (CD) or CDAHFD (BD), before PEG-FGF21v dosing (baseline), and after PEG-FGF21v treatment (WK4/8). Regions of interest for MRI-HFF and MRE-SS were delineated by J.L. and H.T. (>5 years of experience each). Fibrosis and steatosis were measured histologically after picrosirius red and H&E staining. Alkaline phosphatase, alanine transaminase, bile acids, and triglycerides (TGs) were measured. STATISTICAL TESTS: Two-tailed Dunnett's tests were used for statistical analysis; untreated CDAHFD or baseline was used for comparisons. Imaging and histology/biochemistry data were determined using Spearman correlations. Bayesian posterior distributions for MRE-SS at WK8, posterior means, and 95% credible intervals were presented. RESULTS: CDAHFD significantly increased baseline MRI-HFF (3T: 21.97% ± 0.29%; 7T: 40.12% ± 0.35%) and MRE-SS (3T: 1.25 ± 0.02; 7T: 1.78 ± 0.06 kPa) vs. CD (3T: 3.45% ± 0.7%; 7T: 12.06% ± 1.4% and 3T: 1.01 ± 0.02; 7T: 0.89 ± 0.06 kPa). At 7T, PEG-FGF21v significantly decreased MRI-HFF (WK4: 28.97% ± 1.22%; WK8: 20.93% ± 1.15%) and MRE-SS (WK4: 1.57 ± 0.04; WK8: 1.36 ± 0.05 kPa) vs. untreated (WK4: 36.36% ± 0.62%; WK8: 30.58% ± 0.81% and WK4: 2.03 ± 0.06; WK8: 2.01 ± 0.04 kPa); 3T trends were similar. WK8 SS posterior mean percent attenuation ratios (RDI ) were -68% (-90%, -44%; 3T) and -64% (-78%, -52%; 7T). MRI-HFF was significantly correlated with H&E (3T, r = 0.93; 7T, r = 0.94) and TGs (both, r = 0.92). DATA CONCLUSIONS: MRI-HFF and MRE-SS showed PEG-FGF21v effects on hepatic steatosis and fibrosis across 3 and 7T, consistent with histological and biochemical data. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

Discovery of an Oxycyclohexyl Acid Lysophosphatidic Acid Receptor 1 (LPA1) Antagonist BMS-986278 for the Treatment of Pulmonary Fibrotic Diseases.

The oxycyclohexyl acid BMS-986278 (33) is a potent lysophosphatidic acid receptor 1 (LPA1) antagonist, with a human LPA1 Kb of 6.9 nM. The structure-activity relationship (SAR) studies starting from the LPA1 antagonist clinical compound BMS-986020 (1), which culminated in the discovery of 33, are discussed. The detailed in vitro and in vivo preclinical pharmacology profiles of 33, as well as its pharmacokinetics/metabolism profile, are described. On the basis of its in vivo efficacy in rodent chronic lung fibrosis models and excellent overall ADME (absorption, distribution, metabolism, excretion) properties in multiple preclinical species, 33 was advanced into clinical trials, including an ongoing Phase 2 clinical trial in patients with lung fibrosis (NCT04308681).

Transporter Activity Changes in Nonalcoholic Steatohepatitis: Assessment with Plasma Coproporphyrin I and III.

Expression and functional changes in the organic anion transporting polypeptide (OATP)-multidrug resistance-associated protein (MRP) axis of transporters are well reported in patients with nonalcoholic steatohepatitis (NASH). These changes can impact plasma and tissue disposition of endo- and exogenous compounds. The transporter alterations are often assessed by administration of a xenobiotic or by transporter proteomic analysis from liver biopsies. Using gene expression, proteomics, and endogenous biomarkers, we show that the gene expression and activity of OATP and MRP transporters are associated with disease progression and recovery in humans and in preclinical animal models of NASH. Decreased OATP and increased MRP3/4 gene expression in two cohorts of patients with steatosis and NASH, as well as gene and protein expression in multiple NASH rodent models, have been established. Coproporphyrin I and III (CP I and III) were established as substrates of MRP4. CP I plasma concentration increased significantly in four animal models of NASH, indicating the transporter changes. Up to a 60-fold increase in CP I plasma concentration was observed in the mouse bile duct-ligated model compared with sham controls. In the choline-deficient amino acid-defined high-fat diet (CDAHFD) model, CP I plasma concentrations increased by >3-fold compared with chow diet-fed mice. In contrast, CP III plasma concentrations remain unaltered in the CDAHFD model, although they increased in the other three NASH models. These results suggest that tracking CP I plasma concentrations can provide transporter modulation information at a functional level in NASH animal models and in patients. SIGNIFICANCE STATEMENT: Our analysis demonstrates that multidrug resistance-associated protein 4 (MRP4) transporter gene expression tracks with nonalcoholic steatohepatitis (NASH) progression and intervention in patients. Additionally, we show that coproporphyrin I and III (CP I and III) are substrates of MRP4. CP I plasma and liver concentrations increase in different diet- and surgery-induced rodent NASH models, likely explained by both gene- and protein-level changes in transporters. CP I and III are therefore potential plasma-based biomarkers that can track NASH progression in preclinical models and in humans.

Discovery of Potent and Orally Bioavailable Dihydropyrazole GPR40 Agonists.

G protein-coupled receptor 40 (GPR40) has become an attractive target for the treatment of diabetes since it was shown clinically to promote glucose-stimulated insulin secretion. Herein, we report our efforts to develop highly selective and potent GPR40 agonists with a dual mechanism of action, promoting both glucose-dependent insulin and incretin secretion. Employing strategies to increase polarity and the ratio of sp3/sp2 character of the chemotype, we identified BMS-986118 (compound 4), which showed potent and selective GPR40 agonist activity in vitro. In vivo, compound 4 demonstrated insulinotropic efficacy and GLP-1 secretory effects resulting in improved glucose control in acute animal models.

Lysophosphatidic Acid Receptor Antagonism Protects against Diabetic Nephropathy in a Type 2 Diabetic Model.

Lysophosphatidic acid (LPA) functions through activation of LPA receptors (LPARs). LPA-LPAR signaling has been implicated in development of fibrosis. However, the role of LPA-LPAR signaling in development of diabetic nephropathy (DN) has not been studied. We examined whether BMS002, a novel dual LPAR1 and LPAR3 antagonist, affects development of DN in endothelial nitric oxide synthase-knockout db/db mice. Treatment of these mice with BMS002 from 8 to 20 weeks of age led to a significant reduction in albuminuria, similar to that observed with renin-angiotensin system inhibition (losartan plus enalapril). LPAR inhibition also prevented the decline in GFR observed in vehicle-treated mice, such that GFR at week 20 differed significantly between vehicle and LPAR inhibitor groups (P<0.05). LPAR inhibition also reduced histologic glomerular injury; decreased the expression of profibrotic and fibrotic components, including fibronectin, α-smooth muscle actin, connective tissue growth factor, collagen I, and TGF-ß; and reduced renal macrophage infiltration and oxidative stress. Notably, LPAR inhibition slowed podocyte loss (podocytes per glomerulus ±SEM at 8 weeks: 667±40, n=4; at 20 weeks: 364±18 with vehicle, n=7, and 536±12 with LPAR inhibition, n=7; P<0.001 versus vehicle). Finally, LPAR inhibition minimized the production of 4-hydroxynonenal (4-HNE), a marker of oxidative stress, in podocytes and increased the phosphorylation of AKT2, an indicator of AKT2 activity, in kidneys. Thus, the LPAR antagonist BMS002 protects against GFR decline and attenuates development of DN through multiple mechanisms. LPAR antagonism might provide complementary beneficial effects to renin-angiotensin system inhibition to slow progression of DN.

Discovery of Pyrrolidine-Containing GPR40 Agonists: Stereochemistry Effects a Change in Binding Mode.

A novel series of pyrrolidine-containing GPR40 agonists is described as a potential treatment for type 2 diabetes. The initial pyrrolidine hit was modified by moving the position of the carboxylic acid, a key pharmacophore for GPR40. Addition of a 4-cis-CF3 to the pyrrolidine improves the human GPR40 binding Ki and agonist efficacy. After further optimization, the discovery of a minor enantiomeric impurity with agonist activity led to the finding that enantiomers (R,R)-68 and (S,S)-68 have differential effects on the radioligand used for the binding assay, with (R,R)-68 potentiating the radioligand and (S,S)-68 displacing the radioligand. Compound (R,R)-68 activates both Gq-coupled intracellular Ca2+ flux and Gs-coupled cAMP accumulation. This signaling bias results in a dual mechanism of action for compound (R,R)-68, demonstrating glucose-dependent insulin and GLP-1 secretion in vitro. In vivo, compound (R,R)-68 significantly lowers plasma glucose levels in mice during an oral glucose challenge, encouraging further development of the series.

Utilization of the Zucker Diabetic Fatty (ZDF) Rat Model for Investigating Hypoglycemia-related Toxicities.

Glucokinase (GK) catalyzes the initial step in glycolysis and is a key regulator of glucose homeostasis. Therefore, glucokinase activators (GKa) have potential benefit in treating type 2 diabetes. Administration of a Bristol-Myers Squibb GKa (BMS-820132) to healthy euglycemic Sprague-Dawley (SD) rats and beagle dogs in 1 mo toxicology studies resulted in marked and extended hypoglycemia with associated clinical signs of toxicity and degenerative histopathological changes in the stomach, sciatic nerve, myocardium, and skeletal muscles at exposures comparable to those expected at therapeutic clinical exposures. To investigate whether these adverse effects were secondary to exaggerated pharmacology (prolonged hypoglycemia), BMS-820132 was administered daily to male Zucker diabetic fatty (ZDF) rats for 1 mo. ZDF rats are markedly hyperglycemic and insulin resistant. BMS-820132 did not induce hypoglycemia, clinical signs of hypoglycemia, or any of the histopathologic adverse effects observed in the 1 mo toxicology studies at exposures that exceeded those observed in SD rats and dogs. This indicates that the toxicity observed in euglycemic animals was secondary to the exaggerated pharmacology of potent GK activation. This study indicates that ZDF rats, with conventional toxicity studies, are a useful disease model for testing antidiabetic agents and determining toxicities that are independent of prolonged hypoglycemia.

Discovery of 5-chloro-4-((1-(5-chloropyrimidin-2-yl)piperidin-4-yl)oxy)-1-(2-fluoro-4-(methylsulfonyl)phenyl)pyridin-2(1H)-one (BMS-903452), an antidiabetic clinical candidate targeting GPR119.

G-protein-coupled receptor 119 (GPR119) is expressed predominantly in pancreatic ß-cells and in enteroendocrine cells in the gastrointestinal tract. GPR119 agonists have been shown to stimulate glucose-dependent insulin release by direct action in the pancreas and to promote secretion of the incretin GLP-1 by action in the gastrointestinal tract. This dual mechanism of action has generated significant interest in the discovery of small molecule GPR119 agonists as a potential new treatment for type 2 diabetes. Herein, we describe the discovery and optimization of a new class of pyridone containing GPR119 agonists. The potent and selective BMS-903452 (42) was efficacious in both acute and chronic in vivo rodent models of diabetes. Dosing of 42 in a single ascending dose study in normal healthy humans showed a dose dependent increase in exposure and a trend toward increased total GLP-1 plasma levels.

Genetic control of obesity and gut microbiota composition in response to high-fat, high-sucrose diet in mice.

Obesity is a highly heritable disease driven by complex interactions between genetic and environmental factors. Human genome-wide association studies (GWAS) have identified a number of loci contributing to obesity; however, a major limitation of these studies is the inability to assess environmental interactions common to obesity. Using a systems genetics approach, we measured obesity traits, global gene expression, and gut microbiota composition in response to a high-fat/high-sucrose (HF/HS) diet of more than 100 inbred strains of mice. Here we show that HF/HS feeding promotes robust, strain-specific changes in obesity that are not accounted for by food intake and provide evidence for a genetically determined set point for obesity. GWAS analysis identified 11 genome-wide significant loci associated with obesity traits, several of which overlap with loci identified in human studies. We also show strong relationships between genotype and gut microbiota plasticity during HF/HS feeding and identify gut microbial phylotypes associated with obesity.

Diabetic nephropathy and long-term treatment effects of rosiglitazone and enalapril in obese ZSF1 rats.

Diabetic nephropathy (DN) is a major cause of end-stage renal disease. Yet the pathogenic mechanisms underlying the development of DN are not fully defined, partially due to lack of suitable models that mimic the complex pathogenesis of renal disease in diabetic patients. In this study, we describe early and late renal manifestations of DN and renal responses to long-term treatments with rosiglitazone or high-dose enalapril in ZSF1 rats, a model of metabolic syndrome, diabetes, and chronic renal disease. At 8 weeks of age, obese ZSF1 rats developed metabolic syndrome and diabetes (hyperglycemia, glucosuria, hyperlipidemia, and hypertension) and early signs of renal disease (proteinuria, glomerular collagen IV deposition, tubulointerstitial inflammation, and renal hypertrophy). By 32 weeks of age, animals developed renal histopathology consistent with DN, including mesangial expansion, glomerulosclerosis, tubulointerstitial inflammation and fibrosis, tubular dilation and atrophy, and arteriolar thickening. Rosiglitazone markedly increased body weight but reduced food intake, improved glucose control, and attenuated hyperlipidemia and liver and kidney injury. In contrast, rosiglitazone markedly increased cardiac hypertrophy via a blood pressure-independent mechanism. High-dose enalapril did not improve glucose homeostasis, but normalized blood pressure, and nearly prevented diabetic renal injury. The ZSF1 model thus detects the clinical observations seen with rosiglitazone and enalapril in terms of primary and secondary endpoints of cardiac and renal effects. This and previous reports indicate that the obese ZSF1 rat meets currently accepted criteria for progressive experimental diabetic renal disease in rodents, suggesting that this may be the best available rat model for simulation of human DN.

Gene expression analysis in rats treated with experimental acetyl-coenzyme A carboxylase inhibitors suggests interactions with the peroxisome proliferator-activated receptor alpha pathway.

Acetyl CoA carboxylase (ACC) 2, which catalyzes the carboxylation of acetyl-CoA to form malonyl-CoA, has been identified as a potential target for type 2 diabetes and obesity. Small-molecule inhibitors of ACC2 would be expected to reduce de novo lipid synthesis and increase lipid oxidation. Treatment of ob/ob mice with compound A-908292 (S) ({(S)-3-[2-(4-isopropoxy-phenoxy)-thiazol-5-yl]-1-methyl-prop-2-ynyl}-carbamic acid methyl ester), a small-molecule inhibitor with an IC(50) of 23 nM against ACC2, resulted in a reduction of serum glucose and triglyceride levels. However, compound A-875400 (R) ({(R)-3-[2-(4-isopropoxy-phenoxy)-thiazol-5-yl]-1-methyl-prop-2-ynyl}-carbamic acid methyl ester), an inactive enantiomer of A-908292 (S) with approximately 50-fold less activity against ACC2, also caused a similar reduction in glucose and triglycerides, suggesting that the glucose-lowering effects in ob/ob mice may be mediated by other metabolic pathways independent of ACC2 inhibition. To characterize the pharmacological activity of these experimental compounds at a transcriptional level, rats were orally dosed for 3 days with either A-908292 (S) or A-875400 (R), and gene expression analysis was performed. Gene expression analysis of livers showed that treatment with A-908292 (S) or A-875400 (R) resulted in gene expression profiles highly similar to known peroxisome proliferator-activated receptor (PPAR)-alpha activators. The results suggest that, in vivo, both A-908292 (S) and A-875400 (R) stimulated the PPAR-alpha-dependent signaling pathway. These results were further supported by both an in vitro genomic evaluation using rat hepatocytes and immunohistochemical evaluation using 70-kDa peroxisomal membrane protein. Overall, the gene expression analysis suggests a plausible mechanism for the similar pharmacological findings with active and inactive enantiomers of an ACC2 inhibitor.

Liver-selective glucocorticoid receptor antagonism decreases glucose production and increases glucose disposal, ameliorating insulin resistance.

It is unclear how hepatic glucocorticoid receptor (GR) function and hypothalamic-pituitary-adrenal axis tone contribute to the diabetic state and in particular whole-body glucose fluxes. We have previously demonstrated that long-term exposure to hepatic GR inhibition lowers glucose levels in ob/ob mice (J Pharmacol Exp Ther 2005;314:191). The purpose of this study was to determine the effects of a novel GR antagonist (A-348441) on whole-body glucose fluxes in a model of insulin resistance, the Zucker fatty (fa/fa) rat. After an overnight fast, euglycemic-hyperinsulinemic clamp studies were performed 2 hours after single oral dosing as follows: (1) A-348441 at 100 mg/kg or (2) vehicle. Furthermore, effects of 1 week of treatment with either vehicle or A-348441 (3, 10, 30, or 100 mg/kg PO, once per day) were investigated in separate groups of rats fasted overnight and given a final dose of their respective compound, followed 2 hours later by a euglycemic-hyperinsulinemic clamp. One week after catheter implantation, body weight returned to presurgery levels, with no difference between groups. A single, 100-mg/kg dose of A-348441 significantly increased glucose infusion rate 4-fold (P < .05) and reduced endogenous glucose production by 37% (P < .05) but did not change glucose disposal. After 1 week of sub-long-term dosing, fasting glucose levels were reduced dose-dependently with A-348441 vs vehicle (-8%, not significant; -14%, -20%, and -25%, P < .05, at 3, 10, 30, and 100 mg/kg, respectively) with no observed hypoglycemia or change in fasting insulin levels. A-348441 increased the glucose infusion rates after 1-week treatment by 1.3-, 5.7-, 7.3-, and 6.4-fold (P < .05). Endogenous glucose production was decreased (-25%, -44%, -50%, and -61%, P < .05), whereas glucose disposal was increased (29% and 13%, not significant; 23% and 34%, P < .05), with A-348441. In summary, single-dose treatment with the liver-selective GR antagonist A-348441 decreases glucose production with no effect on glucose disposal or fasting glucose levels. After 1 week of treatment with A-348441, (1) there was no effect on body weight, (2) fasting glucose levels decreased, (3) both glucose disposal and glucose infusion rate increased during clamping, and (4) endogenous glucose production was greatly reduced. In addition, hepatic glucose production was highly correlated with fasting glucose levels (r = 0.97). In conclusion, these results indicate that A-348441 increases insulin sensitivity at both the liver and peripheral tissues, leading toward a normalization of the insulin resistant state. Furthermore, with 1-week vs single-dose liver-selective glucocorticoid antagonism, we have determined that the peripheral effect is secondary to the primary event of reduced hepatic glucose production. The approach of inhibiting the hepatic GR may be an advantageous treatment paradigm for individuals with type 2 diabetes mellitus.

Pyrrolidine-constrained phenethylamines: The design of potent, selective, and pharmacologically efficacious dipeptidyl peptidase IV (DPP4) inhibitors from a lead-like screening hit.

A novel series of pyrrolidine-constrained phenethylamines were developed as dipeptidyl peptidase IV (DPP4) inhibitors for the treatment of type 2 diabetes. The cyclohexene ring of lead-like screening hit 5 was replaced with a pyrrolidine to enable parallel chemistry, and protein co-crystal structural data guided the optimization of N-substituents. Employing this strategy, a >400x improvement in potency over the initial hit was realized in rapid fashion. Optimized compounds are potent and selective inhibitors with excellent pharmacokinetic profiles. Compound 30 was efficacious in vivo, lowering blood glucose in ZDF rats that were allowed to feed freely on a mixed meal.

Discovery of ((4R,5S)-5-amino-4-(2,4,5- trifluorophenyl)cyclohex-1-enyl)-(3- (trifluoromethyl)-5,6-dihydro- [1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone (ABT-341), a highly potent, selective, orally efficacious, and safe dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes.

Dipeptidyl peptidase IV (DPP4) deactivates glucose-regulating hormones such as GLP-1 and GIP, thus, DPP4 inhibition has become a useful therapy for type 2 diabetes. Optimization of the high-throughput screening lead 6 led to the discovery of 25 (ABT-341), a highly potent, selective, and orally bioavailable DPP4 inhibitor. When dosed orally, 25 dose-dependently reduced glucose excursion in ZDF rats. Amide 25 is safe in a battery of in vitro and in vivo tests and may represent a new therapeutic agent for the treatment of type 2 diabetes.

Discovery of 2-[4-{{2-(2S,5R)-2-cyano-5-ethynyl-1-pyrrolidinyl]-2-oxoethyl]amino]- 4-methyl-1-piperidinyl]-4-pyridinecarboxylic acid (ABT-279): a very potent, selective, effective, and well-tolerated inhibitor of dipeptidyl peptidase-IV, useful for the treatment of diabetes.

Dipeptidyl peptidase-IV (DPP-IV) inhibitors are poised to be the next major drug class for the treatment of type 2 diabetes. Structure-activity studies of substitutions at the C5 position of the 2-cyanopyrrolidide warhead led to the discovery of potent inhibitors of DPP-IV that lack activity against DPP8 and DPP9. Further modification led to an extremely potent (Ki(DPP)(-)(IV) = 1.0 nM) and selective (Ki(DPP8) > 30 microM; Ki(DPP9) > 30 microM) clinical candidate, ABT-279, that is orally available, efficacious, and remarkably safe in preclinical safety studies.

Selective antagonism of the hepatic glucocorticoid receptor reduces hepatic glucose production.

A liver-selective glucocorticoid (GC) receptor antagonist (A-348441) was used to determine the effect of reduced hepatic GC signaling on hepatic glucose production. Fasted conscious dogs were studied in the presence (GRA, n = 6) or absence (CON, n = 6) of the intraduodenally administered GC receptor antagonist (100 mg/kg). All dogs were maintained on a pancreatic clamp and in a euglycemic state for 7 hours to ensure that any changes in glucose metabolism were the direct result of the effects of A-348441, which was given at the start of a 5-hour experimental period. In the GRA group, the arterial plasma insulin level was 4.6 +/- 0.7 and 4.8 +/- 0.6 microU/mL during the basal and the last 30 minutes of the experimental periods, respectively. In the CON group, it was 4.0 +/- 0.3 and 4.5 +/- 0.5 microU/mL in the 2 periods, respectively. The arterial plasma glucagon level was 49 +/- 4 and 46 +/- 3 pg/mL in the 2 periods in the GRA group, and 45 +/- 3 and 42 +/- 3 pg/mL in the CON group. Net hepatic glucose balance progressively decreased in the GRA group from 1.31 +/- 0.18 to 0.49 +/- 0.30 mg/kg per minute, whereas in the CON group, net hepatic glucose balance was 1.17 +/- 0.09 and 1.43 +/- 0.18 mg/kg per minute during the basal and last 30 minutes of the experimental periods, respectively. No significant change in net renal or gut glucose balance or nonhepatic glucose uptake was observed in either group. This study demonstrates that the GC receptor plays an important role in the regulation of basal hepatic glucose production and represents a significant potential therapeutic target.