Changes in glucose-induced plasma active glucagon-like peptide-1 levels by co-administration of sodium-glucose cotransporter inhibitors with dipeptidyl peptidase-4 inhibitors in rodents.

We investigated whether structurally different sodium-glucose cotransporter (SGLT) 2 inhibitors, when co-administered with dipeptidyl peptidase-4 (DPP4) inhibitors, could enhance glucagon-like peptide-1 (GLP-1) secretion during oral glucose tolerance tests (OGTTs) in rodents. Three different SGLT inhibitors-1-(ß-d-Glucopyranosyl)-4-chloro-3-[5-(6-fluoro-2-pyridyl)-2-thienylmethyl]benzene (GTB), TA-1887, and canagliflozin-were examined to assess the effect of chemical structure. Oral treatment with GTB plus a DPP4 inhibitor enhanced glucose-induced plasma active GLP-1 (aGLP-1) elevation and suppressed glucose excursions in both normal and diabetic rodents. In DPP4-deficient rats, GTB enhanced glucose-induced aGLP-1 elevation without affecting the basal level, whereas metformin, previously reported to enhance GLP-1 secretion, increased both the basal level and glucose-induced elevation. Oral treatment with canagliflozin and TA-1887 also enhanced glucose-induced aGLP-1 elevation when co-administered with either teneligliptin or sitagliptin. These data suggest that structurally different SGLT2 inhibitors enhance plasma aGLP-1 elevation and suppress glucose excursions during OGTT when co-administered with DPP4 inhibitors, regardless of the difference in chemical structure. Combination treatment with DPP4 inhibitors and SGLT2 inhibitors having moderate SGLT1 inhibitory activity may be a promising therapeutic option for improving glycemic control in patients with type 2 diabetes mellitus.

Intestinal Sodium Glucose Cotransporter 1 Inhibition Enhances Glucagon-Like Peptide-1 Secretion in Normal and Diabetic Rodents.

The sodium glucose cotransporter (SGLT) 1 plays a major role in glucose absorption and incretin hormone release in the gastrointestinal tract; however, the impact of SGLT1 inhibition on plasma glucagon-like peptide-1 (GLP-1) levels in vivo is controversial. We analyzed the effects of SGLT1 inhibitors on GLP-1 secretion in normoglycemic and hyperglycemic rodents using phloridzin, CGMI [3-(4-cyclopropylphenylmethyl)-1-(ß-d-glucopyranosyl)-4-methylindole], and canagliflozin. These compounds are SGLT2 inhibitors with moderate SGLT1 inhibitory activity, and their IC50 values against rat SGLT1 and mouse SGLT1 were 609 and 760 nM for phloridzin, 39.4 and 41.5 nM for CGMI, and 555 and 613 nM for canagliflozin, respectively. Oral administration of these inhibitors markedly enhanced and prolonged the glucose-induced plasma active GLP-1 (aGLP-1) increase in combination treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP4) inhibitor, in normoglycemic mice and rats. CGMI, the most potent SGLT1 inhibitor among them, enhanced glucose-induced, but not fat-induced, plasma aGLP-1 increase at a lower dose compared with canagliflozin. Both CGMI and canagliflozin delayed intestinal glucose absorption after oral administration in normoglycemic rats. The combined treatment of canagliflozin and a DPP4 inhibitor increased plasma aGLP-1 levels and improved glucose tolerance compared with single treatment in both 8- and 13-week-old Zucker diabetic fatty rats. These results suggest that transient inhibition of intestinal SGLT1 promotes GLP-1 secretion by delaying glucose absorption and that concomitant inhibition of intestinal SGLT1 and DPP4 is a novel therapeutic option for glycemic control in type 2 diabetes mellitus.

The effect of combined treatment with canagliflozin and teneligliptin on glucose intolerance in Zucker diabetic fatty rats.

To assess the impact of concomitant inhibition of sodium-glucose cotransporter (SGLT) 2 and dipeptidyl peptidase IV (DPP4) for the treatment of type 2 diabetes mellitus (T2DM), the effect of combined treatment with canagliflozin, a novel SGLT2 inhibitor, and teneligliptin, a DPP4 inhibitor, on glucose intolerance was investigated in Zucker diabetic fatty (ZDF) rats. Canagliflozin potently inhibited human and rat SGLT2 and moderately inhibited human and rat SGLT1 activities but did not affect DPP4 activity. In contrast, teneligliptin inhibited human and rat DPP4 activities but not SGLT activities. A single oral treatment of canagliflozin and teneligliptin suppressed plasma glucose elevation in an oral glucose tolerance test in 13 week-old ZDF rats. This combination of agents elevated plasma active GLP-1 levels in a synergistic manner, probably mediated by intestinal SGLT1 inhibition, and further improved glucose intolerance. In the combination-treated animals, there was no pharmacokinetic interaction of the drugs and no further inhibition of plasma DPP4 activity compared with that in the teneligliptin-treated animals. These results suggest that the inhibition of SGLT2 and DPP4 improves glucose intolerance and that combined treatment with canagliflozin and teneligliptin is a novel therapeutic option for glycemic control in T2DM.

Analysis of the effect of canagliflozin on renal glucose reabsorption and progression of hyperglycemia in zucker diabetic Fatty rats.

Sodium-glucose cotransporter 2 (SGLT2) plays a major role in renal glucose reabsorption. To analyze the potential of insulin-independent blood glucose control, the effects of the novel SGLT2 inhibitor canagliflozin on renal glucose reabsorption and the progression of hyperglycemia were analyzed in Zucker diabetic fatty (ZDF) rats. The transporter activity of recombinant human and rat SGLT2 was inhibited by canagliflozin, with 150- to 12,000-fold selectivity over other glucose transporters. Moreover, in vivo treatment with canagliflozin induced glucosuria in mice, rats, and dogs in a dose-dependent manner. It inhibited apparent glucose reabsorption by 55% in normoglycemic rats and by 94% in hyperglycemic rats. The inhibition of glucose reabsorption markedly reduced hyperglycemia in ZDF rats but did not induce hypoglycemia in normoglycemic animals. The change in urinary glucose excretion should not be used as a marker to predict the glycemic effects of this SGLT2 inhibitor. In ZDF rats, plasma glucose and HbA1c levels progressively increased with age, and pancreatic ß-cell failure developed at 13 weeks of age. Treatment with canagliflozin for 8 weeks from the prediabetic stage suppressed the progression of hyperglycemia, prevented the decrease in plasma insulin levels, increased pancreatic insulin contents, and minimized the deterioration of islet structure. These results indicate that selective inhibition of SGLT2 with canagliflozin controls the progression of hyperglycemia by inhibiting renal glucose reabsorption in ZDF rats. In addition, the preservation of ß-cell function suggests that canagliflozin treatment reduces glucose toxicity via an insulin-independent mechanism.

Amiselimod, a novel sphingosine 1-phosphate receptor-1 modulator, has potent therapeutic efficacy for autoimmune diseases, with low bradycardia risk.

BACKGROUND AND PURPOSE: We conducted preclinical and clinical studies to examine the pharmacological, particularly cardiac, effects of amiselimod (MT-1303), a second-generation sphingosine 1-phosphate (S1P) receptor modulator, designed to reduce the bradycardia associated with fingolimod and other S1P receptor modulators. EXPERIMENTAL APPROACH: The selectivity of the active metabolite amiselimod phosphate (amiselimod-P) for human S1P receptors and activation of G-protein-coupled inwardly rectifying K+ (GIRK) channels in human atrial myocytes were assessed. Its cardiac distribution was determined in rats, and cardiovascular telemetry was assessed in monkeys. We also examined the pharmacokinetics, pharmacodynamics and safety of amiselimod in healthy humans. KEY RESULTS: Amiselimod-P showed potent selectivity for S1P1 and high selectivity for S1P5 receptors, with minimal agonist activity for S1P4 and no distinct agonist activity for S1P2 or S1P3 receptors and approximately five-fold weaker GIRK activation than fingolimod-P. After oral administration of amiselimod or fingolimod at 1 mg·kg-1 , the concentration of amiselimod-P in rat heart tissue was lower than that of fingolimod-P, potentially contributing to the minimal cardiac effects of amiselimod. A telemetry study in monkeys confirmed that amiselimod did not affect heart rate or ECG parameters. In healthy human subjects, peripheral blood lymphocyte counts gradually reduced over the 21 day dosing period, with similar lymphocyte count profiles with the highest doses by day 21, and no clinically significant bradycardia observed on day 1 or during the study. CONCLUSIONS AND IMPLICATIONS: Amiselimod exhibited potent therapeutic efficacy with minimal cardiac effects at the anticipated clinical dose and is unlikely to require dose titration.