n-n--((5-(2-amino-5-(2-methylpropyl)-4-thiazolyl)-2-furanyl)phosphinylidene)bis(alanine)-diethyl-ester and Diabetes-Mellitus--Type-2

Fructose-1,6-bisphosphatase (FBPase), a rate-controlling enzyme of gluconeogenesis, has emerged as an important target for the treatment of type 2 diabetes due to the well-recognized role of excessive endogenous glucose production (EGP) in the hyperglycemia characteristic of the disease. Inhibitors of FBPase are expected to fulfill an unmet medical need because the majority of current antidiabetic medications act primarily on insulin resistance or insulin insufficiency and do not reduce gluconeogenesis effectively or in a direct manner. Despite significant challenges, potent and selective inhibitors of FBPase targeting the allosteric site of the enzyme were identified by means of a structure-guided design strategy that used the natural inhibitor, adenosine monophosphate (AMP), as the starting point. Oral delivery of these anionic FBPase inhibitors was enabled by a novel diamide prodrug class. Treatment of diabetic rodents with CS-917, the best characterized of these prodrugs, resulted in a reduced rate of gluconeogenesis and EGP. Of note, inhibition of gluconeogenesis by CS-917 led to the amelioration of both fasting and postprandial hyperglycemia without weight gain, incidence of hypoglycemia, or major perturbation of lactate or lipid homeostasis. Furthermore, the combination of CS-917 with representatives of the insulin sensitizer or insulin secretagogue drug classes provided enhanced glycemic control. Subsequent clinical evaluations of CS-917 revealed a favorable safety profile as well as clinically meaningful reductions in fasting glucose levels in patients with T2DM. Future trials of MB07803, a second generation FBPase inhibitor with improved pharmacokinetics, will address whether this novel class of antidiabetic agents can provide safe and long-term glycemic control.

Topics: Alanine; Animals; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Fructose-Bisphosphatase; Gluconeogenesis; Glucose; Humans; Hypoglycemic Agents; Organophosphonates; Organophosphorus Compounds; Signal Transduction

Metabasis Therapeutics Inc (formerly Gensia Sicor Inc, which became SICOR Inc), in collaboration with Daiichi Sankyo Co Ltd (formerly Sankyo Co Ltd) is developing the fructose-1,6-bisphosphatase inhibitor managlinat dialanetil, a low-molecular weight purine nucleotide analog that inhibits gluconeogenesis, for the potential treatment of type 2 diabetes. Phase II clinical trials of the compound are underway in Europe and the US.

Topics: Alanine; Animals; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Fructose-Bisphosphatase; Humans; Hypoglycemic Agents; Organophosphonates; Organophosphorus Compounds; Structure-Activity Relationship

Oral delivery of previously disclosed purine and benzimidazole fructose-1,6-bisphosphatase (FBPase) inhibitors via prodrugs failed, which was likely due to their high molecular weight (>600). Therefore, a smaller scaffold was desired, and a series of phosphonic acid-containing thiazoles, which exhibited high potency against human liver FBPase (IC(50) of 10-30 nM) and high selectivity relative to other 5'-adenosinemonophosphate (AMP)-binding enzymes, were discovered using a structure-guided drug design approach. The initial lead compound (30j) produced profound glucose lowering in rodent models of type 2 diabetes mellitus (T2DM) after parenteral administration. Various phosphonate prodrugs were explored without success, until a novel phosphonic diamide prodrug approach was implemented, which delivered compound 30j with good oral bioavailability (OBAV) (22-47%). Extensive lead optimization of both the thiazole FBPase inhibitors and their prodrugs culminated in the discovery of compound 35n (MB06322) as the first oral FBPase inhibitor advancing to human clinical trials as a potential treatment for T2DM.

Topics: Administration, Oral; Alanine; Amides; Animals; Biological Availability; Blood Proteins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Fructose-Bisphosphatase; Humans; Hypoglycemic Agents; Male; Mice; Organophosphonates; Prodrugs; Protein Binding; Rats; Rats, Sprague-Dawley; Structure-Activity Relationship; Thiazoles

A novel sulfonylureido pyridine series exemplified by compound 19 yielded potent inhibitors of FBPase showing significant glucose reduction and modest glycogen lowering in the acute db/db mouse model for Type-2 diabetes. Our inhibitors occupy the allosteric binding site and also extend into the dyad interface region of tetrameric FBPase.

Topics: Administration, Oral; Allosteric Site; Aminopyridines; Animals; Crystallography, X-Ray; Diabetes Mellitus, Type 2; Disease Models, Animal; Enzyme Activation; Enzyme Inhibitors; Fructose-Bisphosphatase; Humans; Inhibitory Concentration 50; Liver; Mice; Molecular Structure

Contributions of gluconeogenesis suppression in liver, kidney, and intestine as major gluconeogenic organs to the glucose-lowering effect of CS-917, a fructose 1,6-bisphosphatase inhibitor, was evaluated in overnight-fasted Goto-Kakizaki (GK) rats. CS-917 decreased plasma glucose by suppressing glucose release and lactate uptake from liver but not from kidney and intestine. These results suggest that hepatic gluconeogenesis suppression predominantly contributes to the glucose-lowering effect of CS-917 in GK rats. Moreover, the mechanism by which CS-917 decreased plasma glucose more in overnight-fasted GK rats than in non-fasted ones was investigated. Lactate uptake from liver was suppressed by 15 mg/kg of CS-917 in both states, but glucose release from liver and plasma glucose were decreased only in the overnight-fasted state. CS-917 at 30 mg/kg decreased hepatic glycogen content in both states and depleted it in the overnight-fasted state. In the non-fasted GK rats, co-administration of CS-917 with CP-91149, a glycogen phosphorylase inhibitor, suppressed hepatic glycogen reduction by CS-917 and decreased plasma glucose more than single administration of CS-917. These results suggest that gluconeogenesis suppression by CS-917 was counteracted by hepatic glycogenolysis especially in the non-fasted state and that combination therapy with CS-917 and CP-91149 is efficacious to decrease plasma glucose in GK rats.

Topics: Alanine; Amides; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Fasting; Gluconeogenesis; Glucose; Glycogenolysis; Hypoglycemic Agents; Indoles; Lactic Acid; Male; Organophosphonates; Organophosphorus Compounds; Peptide Hydrolases; Rats

With the aim of exploring the effect of tricyclic-based FBPase inhibitors in cells and in vivo, a series of prodrugs of tricyclic phosphonates was designed and synthesized. Introducing prodrug moieties into tricyclic-based phosphonates led to the discovery of prodrug 15c, which strongly inhibited glucose production in monkey hepatocytes. Furthermore, prodrug 15c lowered blood glucose levels in fasted cynomolgus monkeys.

Topics: Administration, Oral; Animals; Blood Glucose; Cells, Cultured; Crystallography, X-Ray; Diabetes Mellitus, Type 2; Drug Design; Fructose-Bisphosphatase; Glucose; Hepatocytes; Humans; Macaca fascicularis; Models, Molecular; Organophosphonates; Prodrugs

Pancreatic β-cells can precisely sense glucose stimulation and accordingly adjust their insulin secretion. Fructose-1,6-bisphosphatase (FBPase) is a gluconeogenic enzyme, but its physiological significance in β-cells is not established. Here we determined its physiological role in regulating glucose sensing and insulin secretion of β-cells. Considerable FBPase mRNA was detected in normal mouse islets and β-cell lines, although their protein levels appeared to be quite low. Down-regulation of FBP1 in MIN6 cells by small interfering RNA could enhance the glucose-stimulated insulin secretion (GSIS), whereas FBP1-overexpressing MIN6 cells exhibited decreased GSIS. Inhibition of FBPase activity in islet β-cells by its specific inhibitor MB05032 led to significant increase of their glucose utilization and cellular ATP to ADP ratios and consequently enhanced GSIS in vitro. Pretreatment of mice with the MB05032 prodrug MB06322 could potentiate GSIS in vivo and improve their glucose tolerance. Therefore, FBPase plays an important role in regulating glucose sensing and insulin secretion of β-cells and serves a promising target for diabetes treatment.

Topics: Alanine; Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Fructose-Bisphosphatase; Gene Knockdown Techniques; Glucose; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Organophosphonates; Organophosphorus Compounds; RNA, Small Interfering; Thiazoles; Transfection; Up-Regulation

Metformin is an anti-diabetic agent that has been reported to decrease plasma glucose by multiple mechanisms, such as decreasing hepatic glucose production and activating peripheral glucose utilization. In order to elucidate the primary glucose-lowering mechanism of metformin, the present study focused on a comparison of the acute effect between metformin and CS-917 as a direct gluconeogenesis inhibitor. We examined the effect of metformin and CS-917 on glucose turnover in intravenous glucose-loaded Goto-Kakizaki (GK) rats, and on gluconeogenesis and glucose utilization in rat hepatocytes. Moreover, the glucose-lowering effect of metformin and CS-917 was compared in a fed and a fasted state in GK rats. In intravenous glucose-loaded GK rats, metformin and CS-917 lowered plasma glucose by increasing the glucose disappearance rate and by decreasing the glucose appearance rate, respectively. In rat hepatocytes, CS-917 but not metformin suppressed gluconeogenesis (IC(50)=0.136microM). Instead, metformin dose-dependently increased glucose uptake and the following lactate production at 30 to 100microM. Metformin decreased plasma glucose more in a fed state than in a fasted state in GK rats. CS-917, however, decreased plasma glucose more in a fasted state. These results confirm that metformin primarily decreases plasma glucose not by gluconeogenesis inhibition but by activating glucose utilization in GK rats. Moreover, metformin and CS-917 have different glucose-lowering effects depending on the nutrient state, which may be related to differences in their mechanisms of action. Such differences in action may have implications for metformin and CS-917 in the treatment of type 2 diabetes patients.

Topics: Alanine; Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Fructose-Bisphosphatase; Gluconeogenesis; Glucose; Hepatocytes; Hypoglycemic Agents; Inhibitory Concentration 50; Insulin; Lactic Acid; Male; Metformin; Organophosphonates; Organophosphorus Compounds; Radioisotope Dilution Technique; Rats; Rats, Mutant Strains; Rats, Wistar

Postprandial hyperglycemia is one of the features of type 2 diabetes. Increased hepatic gluconeogenesis is a predominant cause of postprandial hyperglycemia in type 2 diabetes. In this study, we evaluated the effect of gluconeogenesis inhibition on postprandial hyperglycemia using CS-917, a novel inhibitor of fructose 1,6-bisphphosphatase (FBPase) which is one of the rate-limiting enzymes of gluconeogenesis. The suppressive effect of CS-917 on postprandial hyperglycemia was evaluated in a meal loading test in Goto-Kakizaki (GK) rats, non-obese type 2 diabetic animal model characterized by impaired insulin secretion. In addition, we describe acute effect of CS-917 on fasting hyperglycemia in overnight-fasted GK rats and chronic effect of CS-917 in multiple dosing GK rats.CS-917 suppressed plasma glucose elevation after meal loading in a dose-dependent manner at doses ranging from 10 to 40 mg/kg. In an overnight-fasted state, CS-917 decreased the plasma glucose levels dose-dependently at doses ranging from 2.5 to 40 mg/kg. Consistent with the inhibition of FBPase, glucose-lowering was associated with an accumulation of hepatic d-fructose 1,6-bisphosphate and a reduction in hepatic d-fructose 6-phosphate. Chronic treatment of CS-917 decreased plasma glucose significantly, and no significant increase in plasma lactate and no profound elevation in plasma triglycerides were observed by both acute and chronic treatment of CS-917 in GK rats.These findings suggest that enhanced gluconeogenesis contributes to hyperglycemia in postprandial conditions as well as in fasting conditions, and that CS-917 as an FBPase inhibitor corrects postprandial hyperglycemia as well as fasting hyperglycemia.

Topics: Alanine; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Enzyme Inhibitors; Fructose-Bisphosphatase; Fructosediphosphates; Fructosephosphates; Gluconeogenesis; Hyperglycemia; Liver; Male; Organophosphonates; Organophosphorus Compounds; Rats; Rats, Wistar

Gluconeogenesis is increased in type 2 diabetes and contributes significantly to fasting and postprandial hyperglycemia. We recently reported the discovery of the first potent and selective inhibitors of fructose 1,6-bisphosphatase (FBPase), a rate-controlling enzyme of gluconeogenesis. Herein we describe acute and chronic effects of the lead inhibitor, MB06322 (CS-917), in rodent models of type 2 diabetes. In fasting male ZDF rats with overt diabetes, a single dose of MB06322 inhibited gluconeogenesis by 70% and overall endogenous glucose production by 46%, leading to a reduction in blood glucose of >200 mg/dl. Chronic treatment of freely feeding 6-week-old male Zucker diabetic fatty (ZDF) rats delayed the development of hyperglycemia and preserved pancreatic function. Elevation of lactate ( approximately 1.5-fold) occurred after 4 weeks of treatment, as did the apparent shunting of precursors into triglycerides. Profound glucose lowering ( approximately 44%) and similar metabolic ramifications were associated with 2-week intervention therapy of 10-week-old male ZDF rats. In high-fat diet-fed female ZDF rats, MB06322 treatment for 2 weeks fully attenuated hyperglycemia without evidence of metabolic perturbation other than a modest reduction in glycogen stores ( approximately 20%). The studies confirm that excessive gluconeogenesis plays an integral role in the pathophysiology of type 2 diabetes and suggest that FBPase inhibitors may provide a future treatment option.

Topics: Alanine; Animals; Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Type 2; Eating; Female; Fructose-Bisphosphatase; Gluconeogenesis; Glucose; Hyperglycemia; Insulin; Ketone Bodies; Lactic Acid; Male; Molecular Structure; Organophosphonates; Organophosphorus Compounds; Pancreas; Rats; Rats, Zucker; Triglycerides

In type 2 diabetes, the liver produces excessive amounts of glucose through the gluconeogenesis (GNG) pathway and consequently is partly responsible for the elevated glucose levels characteristic of the disease. In an effort to find safe and efficacious GNG inhibitors, we targeted the AMP binding site of fructose 1,6-bisphosphatase (FBPase). The hydrophilic nature of AMP binding sites and their widespread use for allosteric regulation of enzymes in metabolic pathways has historically made discovery of AMP mimetics suitable for drug development difficult. By using a structure-based drug design strategy, we discovered a series of compounds that mimic AMP but bear little structural resemblance. The lead compound, MB05032, exhibited high potency and specificity for human FBPase. Oral delivery of MB05032 was achieved by using the bisamidate prodrug MB06322 (CS-917), which is converted to MB05032 in two steps through the action of an esterase and a phosphoramidase. MB06322 inhibited glucose production from a variety of GNG substrates in rat hepatocytes and from bicarbonate in male Zucker diabetic fatty rats. Analysis of liver GNG pathway intermediates confirmed FBPase as the site of action. Oral administration of MB06322 to Zucker diabetic fatty rats led to a dose-dependent decrease in plasma glucose levels independent of insulin levels and nutritional status. Glucose lowering occurred without signs of hypoglycemia or significant elevations in plasma lactate or triglyceride levels. The findings suggest that potent and specific FBPase inhibitors represent a drug class with potential to treat type 2 diabetes through inhibition of GNG.

Topics: Adenosine Monophosphate; Alanine; Analysis of Variance; Animals; Carbon Radioisotopes; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Design; Fructose-Bisphosphatase; Gluconeogenesis; Humans; Liver; Male; Molecular Mimicry; Organophosphonates; Organophosphorus Compounds; Rats; Rats, Sprague-Dawley; Rats, Zucker; Spectrophotometry; Thiazoles