Mode of action and human relevance assessment of male CD-1 mouse renal adenocarcinoma associated with lifetime exposure to empagliflozin.

Inhibition of sodium-glucose cotransporter-2 (SGLT2) has been shown to be a safe and efficacious approach to support managing Type 2 diabetes. In the 2-year carcinogenicity study with the SGLT2 inhibitor empagliflozin in CD-1 mice, an increased incidence of renal tubular adenomas and carcinomas was identified in the male high-dose group but was not observed in female mice. An integrated review of available nonclinical data was conducted to establish a mode-of-action hypothesis for male mouse-specific tumorigenesis. Five key events were identified through systematic analysis to form the proposed mode-of-action: (1) Background kidney pathology in CD-1 mice sensitizes the strain to (2) pharmacology-related diuretic effects associated with SGLT2 inhib ition. (3) In male mice, metabolic demand increases with the formation of a sex- and species-specific empagliflozin metabolite. These features converge to (4) deplete oxidative stress handling reserve, driving (5) constitutive cellular proliferation in male CD-1 mice. The proposed mode of action requires all five key events for empagliflozin to present a carcinogenicity risk in the CD-1 mouse. Considering that empagliflozin is not genotoxic in the standard battery of genotoxicity tests, and not all five key events are present in the context of female mice, rats, or humans, nor for other osmotic diuretics or other SGLT2 inhibitors, the observed male mouse renal tumors are not considered relevant to humans.

Non-invasive assessment of exfoliated kidney cells extracted from urine using multispectral autofluorescence features.

Optimally preserved urinary exfoliated renal proximal tubule cells were assessed by multispectral imaging of cell autofluorescence. We demonstrated different multispectral autofluorescence signals in such cells extracted from the urine of patients with healthy or diseased kidneys. Using up to 10 features, we were able to differentiate cells from individuals with heathy kidneys and impaired renal function (indicated by estimated glomerular filtration rate (eGFR) values) with the receiver operating characteristic area under the curve (AUC) of 0.99. Using the same method, we were also able to discriminate such urine cells from patients with and without renal fibrosis on biopsy, where significant differences in multispectral autofluorescence signals (AUC = 0.90) were demonstrated between healthy and diseased patients (p < 0.05). These findings show that multispectral assessment of the cell autofluorescence in urine exfoliated proximal tubule kidney cells has the potential to be developed as a sensitive, non-invasive diagnostic method for CKD.

Nephrotoxicity and Kidney Transport Assessment on 3D Perfused Proximal Tubules.

Proximal tubules in the kidney play a crucial role in reabsorbing and eliminating substrates from the body into the urine, leading to high local concentrations of xenobiotics. This makes the proximal tubule a major target for drug toxicity that needs to be evaluated during the drug development process. Here, we describe an advanced in vitro model consisting of fully polarized renal proximal tubular epithelial cells cultured in a microfluidic system. Up to 40 leak-tight tubules were cultured on this platform that provides access to the basolateral as well as the apical side of the epithelial cells. Exposure to the nephrotoxicant cisplatin caused a dose-dependent disruption of the epithelial barrier, a decrease in viability, an increase in effluent LDH activity, and changes in expression of tight-junction marker zona-occludence 1, actin, and DNA-damage marker H2A.X, as detected by immunostaining. Activity and inhibition of the efflux pumps P-glycoprotein (P-gp) and multidrug resistance protein (MRP) were demonstrated using fluorescence-based transporter assays. In addition, the transepithelial transport function from the basolateral to the apical side of the proximal tubule was studied. The apparent permeability of the fluorescent P-gp substrate rhodamine 123 was decreased by 35% by co-incubation with cyclosporin A. Furthermore, the activity of the glucose transporter SGLT2 was demonstrated using the fluorescent glucose analog 6-NBDG which was sensitive to inhibition by phlorizin. Our results demonstrate that we developed a functional 3D perfused proximal tubule model with advanced renal epithelial characteristics that can be used for drug screening studies.

Sodium-glucose Cotransporter 2 Inhibitors (SGLT2i): Their Role in Cardiometabolic Risk Management.

BACKGROUND: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a novel category of oral antidiabetic drugs that inhibit renal glucose reabsorption and increase renal glucose excretion, thus lowering plasma glucose levels. This unique mechanism of SGLT2i action is insulin independent, thus improving glycemic control without promoting hypoglycemia in the absence of exogenously administered insulin. METHODS: The present narrative review addresses the putative associations between SGLT2i and several cardiovascular (CV) and microvascular risk factors, as well as their effects on cardiac and renal function. RESULTS: SGLT2i improve several CV risk factors, including fasting and postprandial plasma glucose levels, lipids, blood pressure, body weight, serum uric acid and arterial stiffness. These drugs may also favorably modulate cardiac and renal function via their effects on inflammation, oxidative stress, diuresis, fluid and sodium retention, myocardial function, vascular resistance and 'fuel' metabolism. In the EMPA-REG OUTCOME study, the first published large CV outcome SGLT2i trial, empagliflozin significantly reduced the primary composite outcome (i.e. CV death, nonfatal myocardial infarction or stroke) and all-cause death as well as hospitalization for heart failure. In addition, empagliflozin was associated with a slower progression of kidney disease and lower rates of clinically relevant renal events than was placebo when added to standard care in patients at high CV risk. CONCLUSION: Multiple metabolic benefits may account for the positive clinical outcomes in the EMPA-REG OUTCOME study. Ongoing CV outcome trials involving other SGLT2i will help establish whether the reported CV and microvascular risk benefits are compound-specific or drug class effects.

From the past to future: from energy expenditure to energy intake to energy expenditure.

Although most recent research on energy balance focusses on energy intake (EI) there is still need to think about both sides of the energy balance. Current research on energy expenditure (EE) relates to metabolic adaptation to negative energy balance, mitochondrial metabolism associated with aging, obesity and type 2 diabetes mellitus, the role of EE in hunger and appetite control, non-shivering thermogenesis and brown adipose tissue activity, cellular bioenergetics as a target of obesity treatment and the evolutionary and ecological determinants of EE in humans and other primates. As far as regulation of energy balance is concerned there is recent evidence that EE rather than body weight is under tight control. Biologically, EE is maintained within a narrow physiological range. An EE-set point has been proposed as the width between the upper and lower boundaries of the individual EE range. Regulation of EE may fail in very obese patients with an EI above their upper boundary and after drastic weight loss when patients may go far below their lower EE boundary and thus are loosing control. In population studies, fat-free mass (FFM) and its composition (that is, the proportion of high to low metabolic rate organs) are major determinants of EE. It is tempting to speculate that tight biologic control of EE is related to brain energy need, which is preserved at the cost of peripheral metabolism. There is a moderate heritability of EE, which is independent of the heritability of FFM. In future, metabolic phenotyping should focus on the EE-FFM relationship rather than on EE-values alone.

SGLT2 inhibitors or GLP-1 receptor agonists as second-line therapy in type 2 diabetes: patient selection and perspectives.

Controversy exists regarding the selection of second-line therapy for patients with type 2 diabetes mellitus (T2DM) who are unable to achieve glycemic control with metformin therapy alone. Newer pharmacologic treatments for T2DM include glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors. Both the classes of medication are efficacious, exhibit positive effects on weight, and are associated with minimal risk of hypoglycemia. The purpose of this review is to compare the clinical trial and real-world effectiveness data of glucagon-like peptide-1 receptor agonists versus sodium-glucose cotransporter 2 inhibitors related to A1c reduction, weight loss, cost-effectiveness, cardiovascular outcomes, and safety in patients with T2DM. This review summarizes comparative evidence for providers who are determining which of the two classes may be the most appropriate for a specific patient.

Dapagliflozin, a Sodium-Glucose Co-Transporter 2 Inhibitor, Acutely Reduces Energy Expenditure in BAT via Neural Signals in Mice.

Selective sodium glucose cotransporter-2 inhibitor (SGLT2i) treatment promotes urinary glucose excretion, thereby reducing blood glucose as well as body weight. However, only limited body weight reductions are achieved with SGLT2i treatment. Hyperphagia is reportedly one of the causes of this limited weight loss. However, the effects of SGLT2i treatment on systemic energy expenditure have not been fully elucidated. Herein, we investigated the acute effects of dapagliflozin, a SGLT2i, on systemic energy expenditure in mice. Eighteen hours after dapagliflozin treatment oxygen consumption and brown adipose tissue (BAT) expression of ucp1, a thermogenesis-related gene, were significantly decreased as compared to those after vehicle treatment. In addition, dapagliflozin significantly suppressed norepinephrine (NE) turnover in BAT and c-fos expression in the rostral raphe pallidus nucleus (rRPa) which contains the sympathetic premotor neurons responsible for thermogenesis. These findings indicate that the dapagliflozin-mediated acute decrease in energy expenditure involves a reduction in BAT thermogenesis via decreased sympathetic nerve activity from the rRPa. Furthermore, common hepatic branch vagotomy abolished the reductions in ucp1 expression and NE contents in BAT and c-fos expression in the rRPa. In addition, alterations in hepatic carbohydrate metabolism, such as decreases in glycogen contents and upregulation of phosphoenolpyruvate carboxykinase, manifested prior to the suppression of BAT thermogenesis, e.g. 6 hours after dapagliflozin treatment. Collectively, these results suggest that SGLT2i treatment acutely suppresses energy expenditure in BAT via regulation of an inter-organ neural network consisting of the common hepatic vagal branch and sympathetic nerves.

Diabetic Ketoacidosis in a Patient with Type 2 Diabetes After Initiation of Sodium-Glucose Cotransporter 2 Inhibitor Treatment.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were recently introduced for the treatment of type 2 diabetes (T2D). SGLT2i lower plasma glucose by inhibiting the renal reuptake of glucose leading to glucosuria. Generally, these drugs are considered safe to use. However, recently, SGLT2i have been suggested to predispose to ketoacidosis. Here, we present a case of diabetic ketoacidosis (DKA) developed in an obese, poorly controlled male patient with T2D treated with the SGLT2i dapagliflozin. He was admitted with DKA 5 days after the initiation of treatment with the SGLT2i dapagliflozin. On admission, the primary symptoms were nausea and dizziness, and he was hypertensive (170/103) and tachycardic (119 bpm) and had mild hyperglycaemia (15.3 mmol/l), severe ketonuria and severe metabolic acidosis (pH 7.08). He responded well to infusions of insulin, glucose and saline and was discharged after 72 hr with insulin as the only glucose-lowering therapy. After 1 month, dapagliflozin was reintroduced as add-on to insulin with no recurrent signs of ketoacidosis. During acute illness or other conditions with increased insulin demands in diabetes, SGLT2i may predispose to the formation of ketone bodies and ensuing acidosis.

Demographic and Clinical Profiles of Type 2 Diabetes Mellitus Patients Initiating Canagliflozin Versus DPP-4 Inhibitors in a Large U.S. Managed Care Population.

BACKGROUND: Canagliflozin is the first sodium-glucose co-transporter-2 (SGLT-2) inhibitor-a new class of oral antidiabetic (OAD) medication-approved for type 2 diabetes mellitus (T2DM) treatment in the United States. Approved less than 2 years ago, use of canagliflozin is largely uncharacterized. OBJECTIVE: To investigate and compare baseline demographic, clinical, and economic characteristics of patients initiating canagliflozin and dipeptidyl peptidase-4 (DPP-4) inhibitors in the real-world setting. METHODS: Using administrative claims data from a large, geographically diverse U.S. managed care organization, this retrospective study assessed adult T2DM patients (aged ≥ 18 years) initiating treatment with canagli-flozin or DPP-4 agents. Eligible patients had ≥1 medical claim with a T2DM diagnosis and ≥ 1 outpatient pharmacy claim for canagliflozin or a DPP-4 agent between January 1, 2011, and September 30, 2013. Patients with ≥ 1 canagliflozin fill were selected first and assigned to the canagliflozin cohort following a hierarchical approach; the date of the earliest canagliflozin fill was defined as the index date. Remaining patients with DPP-4 fills were then assigned to the DPP-4 cohort, with the index date as the first DPP-4 fill. Only patients with at least 12 months of pre-index (baseline) enrollment were included. Patients with fills for their cohort-defining drug over 3 months before the index date were excluded in order to focus on new initiators. A subset of patients with ≥ 3 months of continuous enrollment following their index dates was used to examine medication patterns after initiation. Patients with hyperglycemia; type 1, gestational, or nonclinical diabetes; or diabetes with hyperosmolar coma were excluded. Demographic, clinical, and economic characteristics were assessed over baseline and compared using two-sample t-tests or chi-square/Fisher's exact tests. Multivariable logistic regression models were built to assess baseline factors associated with initiation of canagliflozin versus DPP-4. RESULTS: Overall, 1,566 patients initiated canagliflozin, and 26,224 patients initiated DPP-4 treatment. Males constituted slightly more than 60% of each treatment group; mean age was approximately 55 years in each cohort. A significantly smaller proportion of canagliflozin patients (41.3%) initiated treatment with endocrinologists compared with DPP-4 patients (69.2%, P less than 0.001), and canagliflozin patients were more likely (29.4%) to initiate treatment with a primary care physician compared with DPP-4 patients (9.9%, P less than 0.001). Comorbidities were present more frequently in canagliflozin initiators: nephropathy (10.6% vs. 7.0%), retinopathy (10.4% vs. 7.5%), dyslipidemia (82.4% vs. 72.2%), and obesity (24.9% vs. 15.6%), respectively (P less than 0.001 for all comparisons). The mean (SD) Quan-Charlson Comorbidity Index score was greater for canagliflozin, 1.05 (1.7), compared with DPP-4 initiators, 0.92 (1.6), P = 0.002. Among the subset of patients with available hemoglobin A1c (A1c) results, a significantly smaller proportion of canagliflozin initiators (16.5%) versus DPP-4 initiators (26.7%) were at the A1c less than 7% treatment goal at baseline (P less than 0.001). Among patients with 3 months follow-up, 89.2% of canagliflozin and 75.1% of DPP-4 initiators had ≥ 1 fill for their index drugs over this time frame. Canagliflozin initiators had significantly greater baseline utilization of office visits, endocrinologist and outpatient services, and more prescription fills. Total diabetes-related medical costs at baseline ($3,025 vs. $3,477 for canagliflozin and DPP-4 initiators) were not significantly different, while mean diabetes-related pharmacy costs were higher in the canagliflozin group ($4,037 vs. $1,411, P less than 0.001). Regression analysis indicated that baseline insulin and glucagon-like peptide-1 use, as well as comorbid dyslipidemia and obesity, were significantly associated with the initiation of canagliflozin versus DPP-4 agents. CONCLUSIONS: In this sample of commercially insured patients within a large managed care plan, canagliflozin was often initiated as second- or third-line therapy, with a relatively high share of patients receiving concomitant antidiabetic injectables, compared with DPP-4 initiators. Canagliflozin initiators had highly elevated A1c levels and were frequently diagnosed with other metabolic conditions. Baseline pharmacy utilization and costs were higher among canagliflozin patients. Future research is needed to assess real-world clinical outcomes after canagliflozin initiation, while taking these baseline differences into account.

Effect of food on the pharmacokinetics of canagliflozin, a sodium glucose co-transporter 2 inhibitor, and assessment of dose proportionality in healthy participants.

Canagliflozin, an orally active inhibitor of sodium glucose co-transporter 2, is approved for the treatment of type-2 diabetes mellitus. The effect of food on the pharmacokinetics of 300 mg canagliflozin, and dose proportionality of 50, 100, and 300 mg canagliflozin, were evaluated, in two studies, in healthy participants. Study 1 used a randomized, 2-way crossover design: canagliflozin 300 mg/day was administered under fasted (Period-1) and fed (Period-2) conditions or vice versa. Study 2 was a 3-way crossover: participants were randomized to receive three single-doses of canagliflozin (50, 100, and 300 mg), one in each period. In both studies, treatment periods were separated by washout intervals of 10-14 days, and pharmacokinetics assessed up to 72 hours postdose of each treatment period. No clinically relevant food effects on canagliflozin exposure parameters were observed: 90% confidence intervals (CIs) for the fed/fasted geometric mean ratios of AUC∞ (ratio: 100.51; 90% CI: 89.47-112.93) and Cmax (ratio: 108.09; 90% CI: 103.45-112.95) were entirely within bioequivalence limits (80-125%). Plasma canagliflozin exposures were dose-proportional as the 90% CI of the slope of the regression line for dose-normalized AUC∞ and Cmax fell entirely within the prespecified limits of -0.124 to 0.124. No clinically significant safety issues were noted, and canagliflozin was generally well-tolerated.

Emerging sodium/glucose co-transporter 2 inhibitors for type 2 diabetes.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a public health challenge globally. Numerous treatments are available which can improve insulin sensitivity or stimulate its secretion including biguanides, sulphonylureas and glitazones, as well as insulin, GLP-1 agonists and DPP-IV inhibitors. These are usually unable to halt progression with high resulting morbidity and mortality. New therapies are, therefore, being developed; inhibition of glucose reabsorption from the renal filtrate has been proposed as a novel therapeutic target, and sodium/glucose co-transporter 2 (SGLT2) inhibitors have been developed accordingly. AREAS COVERED: This review summarises the challenge that T2DM poses and describes established therapies. The market for these therapies and likely changes are examined, as well as the scientific rationale behind the development of SGLT2 inhibitors. SGLT2 inhibitors in clinical trials worldwide are reviewed and issues affecting their development are discussed. EXPERT OPINION: SGLT2 inhibitors offer a novel therapeutic approach to the management of T2DM; advantages over other agents include weight loss and blood pressure lowering with a low intrinsic risk of hypoglycaemia. The main adverse effects likely to be seen in clinical practice are a very small increase in risk of urinary tract infections, and a modest risk of developing genital fungal infections - which appear more common in the first few months of treatment. Meta-analyses suggest no increased risk of cardiovascular disease, but longer duration outcome studies are essential to prove long-term safety and efficacy.

Assessment of the drug interaction risk for remogliflozin etabonate, a sodium-dependent glucose cotransporter-2 inhibitor: evidence from in vitro, human mass balance, and ketoconazole interaction studies.

Remogliflozin etabonate is the ester prodrug of remogliflozin, a selective sodium-dependent glucose cotransporter-2 inhibitor. This work investigated the absorption, metabolism, and excretion of [(14)C]remogliflozin etabonate in humans, as well as the influence of P-glycoprotein (Pgp) and cytochrome P450 (P450) enzymes on the disposition of remogliflozin etabonate and its metabolites to understand the risks for drug interactions. After a single oral 402 ± 1.0 mg (106 ± 0.3 µCi) dose, [(14)C]remogliflozin etabonate is rapidly absorbed and extensively metabolized. The area under the concentration-time curve from 0 to infinity [AUC((0-∞))] of plasma radioactivity was approximately 14-fold higher than the sum of the AUC((0-∞)) of remogliflozin etabonate, remogliflozin, and 5-methyl-4-({4-[(1-methylethyl)oxy]phenyl}methyl)-1H-pyrazol-3-yl-ß-d-glucopyranoside (GSK279782), a pharmacologically active N-dealkylated metabolite. Elimination half-lives of total radioactivity, remogliflozin etabonate, and remogliflozin were 6.57, 0.39, and 1.57 h, respectively. Products of remogliflozin etabonate metabolism are eliminated primarily via renal excretion, with 92.8% of the dose recovered in the urine. Three glucuronide metabolites made up the majority of the radioactivity in plasma and represent 67.1% of the dose in urine, with 5-methyl-1-(1-methylethyl)-4-({4-[(1-methylethyl)oxy]phenyl}methyl)-1H-pyrazol-3-yl-ß-d-glucopyranosiduronic acid (GSK1997711) representing 47.8% of the dose. In vitro studies demonstrated that remogliflozin etabonate and remogliflozin are Pgp substrates, and that CYP3A4 can form GSK279782 directly from remogliflozin. A ketoconazole clinical drug interaction study, along with the human mass balance findings, confirmed that CYP3A4 contributes less than 50% to remogliflozin metabolism, demonstrating that other enzyme pathways (e.g., P450s, UDP-glucuronosyltransferases, and glucosidases) make significant contributions to the drug's clearance. Overall, these studies support a low clinical drug interaction risk for remogliflozin etabonate due to the availability of multiple biotransformation pathways.