piragliatin and Diabetes-Mellitus--Type-2

To determine the effect of piragliatin on the QTcS (QT-corrected study-specific) interval, a double-blind, double-dummy, placebo-controlled, active-comparator, 4-period, 4-treatment, 4-sequence randomized crossover trial was performed in 42 patients with type 2 diabetes mellitus who received 100 and 200 mg piragliatin twice daily, placebo, and 400 mg moxifloxacin (on day 1 and day 5 only) for 5 days. In the categorical analyses, piragliatin did not have a clinically significant effect on the QTcS interval at either dose, and the majority of patients were categorized with low risk for maximum change from baseline (≤30 milliseconds) and a maximum postbaseline QTcS interval as normal (≤450 milliseconds). However, in the analysis of variance model, both piragliatin doses crossed the 10-millisecond threshold (100 mg twice daily on day 5, hour 1; 200 mg twice daily on days 1 and 5, hours 1 and 2) with P values indicating statistical significance. Headache and mild hypoglycemia were the most frequent adverse events associated with piragliatin treatment. There appeared that the effect of piragliatin treatment on the QTc interval was dose/exposure dependent following short-term multiple doses. Longer-term monitoring of electrocardiograms with pharmacokinetic exposure should continue, especially at conditions for potentially higher pharmacokinetic exposure.

Topics: Adult; Aged; Benzeneacetamides; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Fluoroquinolones; Heart Rate; Humans; Male; Middle Aged; Moxifloxacin

To assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of piragliatin, a double-blind, randomized, placebo-controlled, multiple-ascending-doses study was conducted in patients with type 2 diabetes mellitus (T2D). Fifty-nine T2D patients were given piragliatin or placebo in a dose-escalation design as a single dose on day 1 followed by multiple doses on days 3 through 8 at doses of 10, 25, 50, 100, and 200 mg twice a day (BID) as well as 200 mg every day (QD). Blood and urine samples were collected for PK analysis. PD assessments included plasma glucose, insulin, C-peptide, glucagon, and GLP-1. Piragliatin exposure was dose proportional without appreciable accumulation or food effect. Piragliatin treatment at steady state yielded dose-dependent reductions up to 32.5% and 35.5% for the highest dose in fasting and postprandial plasma glucose. Piragliatin was well tolerated. Mild or moderate hypoglycemia with rapid recovery after sugar-containing drinks or scheduled meals was the only dose-limiting adverse event. It is concluded that multiple doses of piragliatin consistently showed rapid, dose-dependent glucose reduction of fasting and postprandial plasma glucose in T2D patients.

Topics: Adult; Aged; Benzeneacetamides; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Fasting; Female; Humans; Hypoglycemic Agents; Male; Middle Aged; Postprandial Period

Piragliatin is a CYP3A substrate; its inactive metabolite M4, formed through cytosolic reductase, is reversibly metabolized back to piragliatin through CYP3A. The impact of concomitant CYP3A modifiers thus cannot be predicted. Drinking alcohol under fasting conditions is associated with a recognized glucose-lowering effect, which might be synergistic with piragliatin's hypoglycemic effect. Two exploratory studies were conducted to examine these potential interactions in type 2 diabetes (T2D) patients: 16 completed an open-label, sequential 2-way crossover, 2-arm (randomized to ketoconazole and rifampicin) CYP3A study; another 18 participated in a double-blind, placebo-controlled, randomized 3-way crossover ethanol study. Administration of piragliatin (100-mg single dose) resulted in a 32% Cmax and 44% area under the curve (AUC∞ ) increase in piragliatin exposure without affecting glucose AUC0-6h following ketoconazole (400 mg QD × 5 days); 30% Cmax and 72% AUC∞ decrease in piragliatin exposure with a 13% increase in glucose AUC0-6h following rifampicin (600 mg QD × 5 days); and, unexpectedly, a 32% Cmax and 23% AUC0-6h decrease (no change in AUC∞ ) in piragliatin exposure with a 13% increase in glucose AUC0-6h following alcohol (40-g single dose). In conclusion, a strong CYP3A modifier or concomitant alcohol could lead to a change in exposure to piragliatin with a potential alteration in glucose-lowering effect.

Topics: Adult; Aged; Benzeneacetamides; Blood Glucose; Cross-Over Studies; Cytochrome P-450 CYP3A Inducers; Cytochrome P-450 CYP3A Inhibitors; Diabetes Mellitus, Type 2; Double-Blind Method; Ethanol; Female; Humans; Hypoglycemic Agents; Ketoconazole; Male; Middle Aged; Rifampin

To evaluate the potential pharmacokinetic (PK) and pharmacodynamic (PD, glucose-lowering effect) interaction between simvastatin and piragliatin, both CYP3A substrates, 30 patients with type 2 diabetes mellitus participated in this open-label, randomized, 6-sequence, 3-way crossover (William's design) study. During 3 periods, patients were randomized to receive a single dose of 80 mg simvastatin alone, a single dose of 100 mg piragliatin alone, as well as single doses of 80 mg simvastatin and 100 mg piragliatin together. Primary PK and PD parameters were AUCs on dosing days. The ratio of geometric means (90% confidence intervals) of the AUCinf of piragliatin coadministered with simvastatin compared with piragliatin alone was 0.98 (0.92-1.05), whereas that of the AUCinf of simvastatin acid (active metabolite) coadministered with piragliatin compared with simvastatin alone, was 1.02 (0.90-1.16), suggesting lack of pharmacokinetic interaction between piragliatin and simvastatin. Piragliatin's glucose-lowering effect was not affected by coadministration of simvastatin. Overall, administration of piragliatin with simvastatin was without additional clinically relevant adverse effects as well as abnormality in laboratory tests, vital signs, and electrocardiogram parameters. Concomitant administration of simvastatin and piragliatin, both CYP3A substrates, has no clinically relevant effect on the pharmacokinetics of either piragliatin or simvastatin or on the pharmacodynamics for piragliatin.

Topics: Adult; Aged; Benzeneacetamides; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Interactions; Drug Therapy, Combination; Enzyme Activators; Female; Glucokinase; Humans; Male; Middle Aged; Simvastatin

A glucokinase activator and a sulfonylurea might be coprescribed to synergize treatment success for type 2 diabetes (T2D). This clinical pharmacology study was designed to investigate the potential glucose-lowering effect or pharmacodynamic (PD), pharmacokinetic (PK), and safety/tolerability interactions between piragliatin and glyburide in T2D patients already taking glyburide but not adequately controlled. This was an open-label, multiple-dose, 3-period, single-sequence crossover design: on days -1, 6, and 12, PD and PK samples were drawn with glyburide alone (period 0), piragliatin + glyburide (period 1), and piragliatin alone (period 2) treatments. The glucose-lowering effect, including fasting plasma glucose (FPG), of piragliatin was more pronounced when it was administered concomitantly with glyburide as compared to piragliatin or glyburide administered alone. However, this enhancement cannot be explained by a potential PK interaction between piragliatin and glyburide. Other than hypoglycemia, there were no clinically relevant safety findings. Thus, the enhanced PD effect warrants further investigation to define the optimal dose combination between glucokinase activators and sulfonylureas with regard to efficacy, safety, and tolerability.

Topics: Adult; Aged; Benzeneacetamides; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Endpoint Determination; Enzyme Activators; Female; Glucokinase; Glyburide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Sitagliptin Phosphate

Glucokinase plays a key role in glucose homeostasis. Glucokinase activators can lower glucose levels in both animal and human type 2 diabetes, but their mechanism of action has never been explored in humans.. The objective of the study was to investigate the effects of the glucokinase activator piragliatin (RO4389620) on β-cell function and glucose fluxes in both fasting and fed (oral glucose tolerance test) states in patients with type 2 diabetes.. This was a phase Ib randomized, double-blind, placebo-controlled crossover trial of two (25 and 100 mg) doses of piragliatin.. This study was conducted at a clinical research center.. Patients included 15 volunteer ambulatory patients with mild type 2 diabetes.. Interventions included three 10-h (-300' to +300') studies, with an interval of at least 14 d. Administration of a single dose of placebo or piragliatin 25 mg or piragliatin 100 mg at -120'. Oral glucose tolerance test (at 0') with dual (iv and oral routes) tracer dilution technique was conducted.. The primary measure was plasma glucose concentration. The secondary measure was model assessed β-cell function and tracer-determined glucose fluxes.. Piragliatin caused a dose-dependent reduction of glucose levels in both fasting and fed states (P < 0.01). In the fasting state, piragliatin caused a dose-dependent increase in β-cell function, a fall in endogenous glucose output, and a rise in glucose use (all P < 0.01). In the fed state, the primary effects of piragliatin were on β-cell function (P < 0.01).. The glucokinase activator piragliatin has an acute glucose-lowering action in patients with mild type 2 diabetes, mainly mediated through a generalized enhancement of β-cell function and through fasting restricted changes in glucose turnover.

Topics: Analysis of Variance; Benzeneacetamides; Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucokinase; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells

Glucokinase (GK) is an enzyme that plays an important role as a glucose sensor while maintaining whole body glucose homeostasis. Allosteric activators of GK (GKAs) have the potential to treat type 2 diabetes mellitus. To identify novel GKAs, a series of compounds based on a thiophenyl-pyrrolidine scaffold were designed and synthesized. In this series, compound 38 was found to inhibit glucose excursion in an oral glucose tolerance test (OGTT) in mice. Optimization of 38 using a zwitterion approach led to the identification of the novel GKA 59. GKA 59 exhibited potent blood glucose control in the OGTT test as well as a favorable safety profile. Owing to low pancreatic distribution, compound 59 primarily activates GK in the liver. This characteristic could overcome limitations of other GKAs, such as hypoglycemia, increased plasma triglycerides, and loss of efficacy.

Topics: Animals; Diabetes Mellitus, Type 2; Enzyme Activators; Glucokinase; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Liver; Male; Mice, Inbred C57BL; Pancreas; Pyrrolidines; Thiophenes

Ligand-target residence time is emerging as a key drug discovery parameter because it can reliably predict drug efficacy in vivo. Experimental approaches to binding and unbinding kinetics are nowadays available, but we still lack reliable computational tools for predicting kinetics and residence time. Most attempts have been based on brute-force molecular dynamics (MD) simulations, which are CPU-demanding and not yet particularly accurate. We recently reported a new scaled-MD-based protocol, which showed potential for residence time prediction in drug discovery. Here, we further challenged our procedure's predictive ability by applying our methodology to a series of glucokinase activators that could be useful for treating type 2 diabetes mellitus. We combined scaled MD with experimental kinetics measurements and X-ray crystallography, promptly checking the protocol's reliability by directly comparing computational predictions and experimental measures. The good agreement highlights the potential of our scaled-MD-based approach as an innovative method for computationally estimating and predicting drug residence times.

Topics: Crystallography, X-Ray; Diabetes Mellitus, Type 2; Glucokinase; Humans; Isoenzymes; Kinetics; Ligands; Models, Molecular; Molecular Dynamics Simulation; Molecular Structure; Structure-Activity Relationship; Time Factors

Glucokinase (GK) activation as a potential strategy to treat type 2 diabetes (T2D) is well recognized. Compound 1, a glucokinase activator (GKA) lead that we have previously disclosed, caused reversible hepatic lipidosis in repeat-dose toxicology studies. We hypothesized that the hepatic lipidosis was due to the structure-based toxicity and later established that it was due to the formation of a thiourea metabolite, 2. Subsequent SAR studies of 1 led to the identification of a pyrazine-based lead analogue 3, lacking the thiazole moiety. In vivo metabolite identification studies, followed by the independent synthesis and profiling of the cyclopentyl keto- and hydroxyl- metabolites of 3, led to the selection of piragliatin, 4, as the clinical lead. Piragliatin was found to lower pre- and postprandial glucose levels, improve the insulin secretory profile, increase β-cell sensitivity to glucose, and decrease hepatic glucose output in patients with T2D.

Topics: Animals; Benzeneacetamides; Diabetes Mellitus, Type 2; Dogs; Enzyme Activators; Female; Glucokinase; Glucose; Humans; Hypoglycemic Agents; Lipidoses; Liver; Macaca fascicularis; Male; Mice; Mice, Inbred C57BL; Postprandial Period; Rabbits; Rats; Rats, Wistar; Stereoisomerism; Structure-Activity Relationship

It was reported previously that isolated human islets from individuals with type 2 diabetes mellitus (T2DM) show reduced glucose-stimulated insulin release. To assess the possibility that impaired bioenergetics may contribute to this defect, glucose-stimulated respiration (Vo(2)), glucose usage and oxidation, intracellular Ca(2+), and insulin secretion (IS) were measured in pancreatic islets isolated from three healthy and three type 2 diabetic organ donors. Isolated mouse and rat islets were studied for comparison. Islets were exposed to a "staircase" glucose stimulus, whereas IR and Vo(2) were measured. Vo(2) of human islets from normals and diabetics increased sigmoidally from equal baselines of 0.25 nmol/100 islets/min as a function of glucose concentration. Maximal Vo(2) of normal islets at 24 mM glucose was 0.40 ± 0.02 nmol·min(-1)·100 islets(-1), and the glucose S(0.5) was 4.39 ± 0.10 mM. The glucose stimulation of respiration of islets from diabetics was lower, V(max) of 0.32 ± 0.01 nmol·min(-1)·100 islets(-1), and the S(0.5) shifted to 5.43 ± 0.13 mM. Glucose-stimulated IS and the rise of intracellular Ca(2+) were also reduced in diabetic islets. A clinically effective glucokinase activator normalized the defective Vo(2), IR, and free calcium responses during glucose stimulation in islets from type 2 diabetics. The body of data shows that there is a clear relationship between the pancreatic islet energy (ATP) production rate and IS. This relationship was similar for normal human, mouse, and rat islets and the data for all species fitted a single sigmoidal curve. The shared threshold rate for IS was ∼13 pmol·min(-1)·islet(-1). Exendin-4, a GLP-1 analog, shifted the ATP production-IS curve to the left and greatly potentiated IS with an ATP production rate threshold of ∼10 pmol·min(-1)·islet(-1). Our data suggest that impaired β-cell bioenergetics resulting in greatly reduced ATP production is critical in the molecular pathogenesis of type 2 diabetes mellitus.

Topics: Adult; Animals; Benzeneacetamides; Calcium Signaling; Cell Respiration; Diabetes Mellitus, Type 2; Enzyme Activators; Exenatide; Female; Glucagon-Like Peptide 1; Glucokinase; Glucose; Glycolysis; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Middle Aged; Oxidative Phosphorylation; Peptides; Rats; Species Specificity; Tissue Culture Techniques; Venoms