An assessment of adverse effects of vildagliptin versus comparators on the liver, the pancreas, the immune system, the skin and in patients with impaired renal function from a large pooled database of Phase II and III clinical trials

Dipeptidyl peptidase-4 inhibitors and the risk of infection: A systematic review and meta-analysis of cardiovascular outcome trials

BACKGROUND

Since adverse events during treatment affect adherence and subsequent glycemic control, understanding the safety profile of oral anti-diabetic drugs is imperative for type 2 diabetes mellitus (T2DM) therapy.

AIM

To evaluate the risk of infection in patients with T2DM treated with dipeptidyl-peptidase 4 (DPP-4) inhibitors.

METHODS

Electronic databases were searched. The selection criteria included randomized controlled trials focused on cardiovascular outcomes. In these studies, the effects of DPP-4 inhibitors were directly compared to those of either other active anti-diabetic treatments or placebo. Six trials involving 53616 patients were deemed eligible. We calculated aggregate relative risks employing both random-effects and fixed-effects approaches, contingent upon the context.

RESULTS

The application of DPP-4 inhibitors showed no significant link to the overall infection risk [0.98 (0.95, 1.02)] or the risk of serious infections [0.96 (0.85, 1.08)], additionally, no significant associations were found with opportunistic infections [0.69 (0.46, 1.04)], site-specific infections [respiratory infection 0.99 (0.96, 1.03), urinary tract infections 1.02 (0.95, 1.10), abdominal and gastrointestinal infections 1.02 (0.83, 1.25), skin structure and soft tissue infections 0.81 (0.60, 1.09), bone infections 0.96 (0.68, 1.36), and bloodstream infections 0.97 (0.80, 1.18)].

CONCLUSION

This meta-analysis of data from cardiovascular outcome trials revealed no heightened infection risk in patients undergoing DPP-4 inhibitor therapy compared to control cohorts.

Management of type 2 diabetes in patients with compensated liver cirrhosis: Short of evidence, plenty of potential

BACKGROUND AND AIMS

Treatment of type 2 diabetes (T2D) in patients with compensated cirrhosis is challenging due to hypoglycemic risk, altered pharmacokinetics, and the lack of robust evidence on the risk/benefit ratio of various drugs. Suboptimal glycemic control accelerates the progression of cirrhosis, while the frequent coexistence of nonalcoholic fatty liver disease (NAFLD) with T2D highlights the need for a multifactorial therapeutic approach.

METHODS

A literature search was performed in Medline, Google Scholar and Scopus databases till July 2023, using relevant keywords to extract studies regarding the management of T2D in patients with compensated cirrhosis.

RESULTS

Metformin, sodium-glucose co-transporter-2 inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RA) are promising treatment options for patients with T2D and compensated liver cirrhosis, offering good glycemic control with minimal risk of hypoglycemia, while their pleiotropic actions confer benefits on NAFLD and body weight, and decrease cardiorenal risk. Sulfonylureas cause hypoglycemia, thus should be avoided, while in specific studies, dipeptidyl peptidase-4 inhibitors have been correlated with increased risk of decompensation and variceal bleeding. Despite the benefits of thiazolidinediones in nonalcoholic steatohepatitis, concerns about edema and weight gain limit their use in compensated cirrhosis. Insulin does not exert hepatotoxic effects and can be administered safely in combination with other drugs; however, the risk of hypoglycemia should be considered.

CONCLUSIONS

The introduction of new hepatoprotective diabetes drugs into clinical practice, including tirzepatide, SGLT2i, and GLP-1 RA, sets the stage for future trials to investigate the ideal therapeutic regimen for people with T2D and compensated cirrhosis.

DPP-4 inhibitors for treating T2DM - hype or hope? an analysis based on the current literature

DPP-4 inhibition is an interesting line of therapy for treating Type 2 Diabetes Mellitus (T2DM) and is based on promoting the incretin effect. Here, the authors have presented a brief appraisal of DPP-4 inhibitors, their modes of action, and the clinical efficiency of currently available drugs based on DPP-4 inhibitors. The safety profiles as well as future directions including their potential application in improving COVID-19 patient outcomes have also been discussed in detail. This review also highlights the existing queries and evidence gaps in DPP-4 inhibitor research. Authors have concluded that the excitement surrounding DPP-4 inhibitors is justified because in addition to controlling blood glucose level, they are good at managing risk factors associated with diabetes.

Sustained-Release Vildagliptin 100 mg in Type 2 Diabetes Mellitus: A Review

Dipeptidyl peptidase-4 inhibitors (DPP4Is) were introduced into the management of type 2 diabetes mellitus (T2DM) as they are insulinotropic and have no inherent risk of hypoglycemia and no effect on body weight. Currently, 11 drugs in this class are available for the management of diabetes. Although they have a similar mechanism of action, they differ from one other in their binding mechanisms, which influences their therapeutic and pharmacological profiles. Vildagliptin's overall safety and tolerability profile was comparable to placebo throughout clinical studies, and real-world data in a large group of T2DM patients corroborated this finding. Therefore, DPP4Is like vildagliptin is a secure alternative for treating patients with T2DM. Vildagliptin treatment given as a once-daily (QD) 100 mg sustained release (SR) formulation fits the criteria of adherence and compliance. This SR formulation, given once daily has the potential to provide glycemic control like the vildagliptin 50 mg twice-daily (BD) formulation. This comprehensive review discusses the journey of vildagliptin as 50 mg BD therapy as well as 100 mg SR QD therapy.

Diabetes medications and risk of HCC

Type 2 diabetes mellitus is a recognized risk factor for HCC in patients with liver disease, independent from the etiology of their liver disease. Hence, prevention and treatment of type 2 diabetes mellitus and its underlying cause, insulin resistance, should be considered a treatment target for patients with liver disease. The drug armamentarium for diabetes is wide and consists of agents with insulin-sensitizing activity, agents that stimulate insulin secretion, insulin itself, and agents that reduce gastrointestinal and urinary glucose absorption. From an endocrinology perspective, the main goal of treatment is the achievement of euglycemia; however, in patients at risk of, or with known underlying liver disease, the choice of diabetic medication as it relates to potential hepatic carcinogenesis remains complex and should be carefully considered. In the last decade, increasing evidence has suggested that metformin may reduce the risk of HCC, whereas evidence for other classes of diabetic medications, particularly some of the newer agents including the sodium glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, is fewer and often inconsistent. In this review, we aim to summarize the current evidence on the potential effects of the most widely used diabetic agents on liver cancer tumorigenesis.

An Approach to the Management of Diabetes Mellitus in Cirrhosis: A Primer for the Hepatologist

The management of diabetes in cirrhosis and liver transplantation can be challenging. There is difficulty in diagnosis and monitoring of diabetes as fasting blood sugar values are low and glycosylated hemoglobin may not be a reliable marker. The challenges in the management of diabetes in cirrhosis include the likelihood of cognitive impairment, risk of hypoglycemia, altered drug metabolism, frequent renal dysfunction, risk of lactic acidosis, and associated malnutrition and sarcopenia. Moreover, calorie restriction and an attempt to lose weight in obese diabetics may be associated with a worsening of sarcopenia. Many commonly used antidiabetic drugs may be unsafe or be associated with a high risk of hypoglycemia in cirrhotics. Post-transplant diabetes is common and may be contributed by immunosuppressive medication. There is inadequate clinical data on the use of antidiabetic drugs in cirrhosis, and the management of diabetes in cirrhosis is hampered by the lack of guidelines focusing on this issue. The current review aims at addressing the practical management of diabetes by a hepatologist.

Dipeptidyl peptidase-4 inhibitor treatment and the risk of bullous pemphigoid and skin-related adverse events: A systematic review and meta-analysis of randomized controlled trials

AIMS

This meta-analysis aimed to evaluate the risk of developing bullous pemphigoid (BP) and other skin-related adverse events (AEs) in patients with type 2 diabetes (T2DM) undergoing dipeptidyl peptidase-4 inhibitor (DPP-4i) treatment in randomized controlled trials (RCTs).

METHODS

In this meta-analysis, the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for RCTs, which involve patients with T2DM reporting skin-related AEs. RCTs that comparatively evaluated the effects of DPP-4i treatment and placebo on patients with T2DM and reported skin-related AEs were included in the analysis. The odds ratio (OR) and 95% confidence interval (CI) were calculated using the Peto's methods. The GRADE approach was used to rate the quality of evidence.

RESULTS

A total of 46 randomized placebo-controlled trials, including 3 trials with reports of BP (n = 38 011), that reported skin-related AEs were included (n = 59 332). Compared to the placebo group, the risk of developing BP was significantly higher in the DPP-4i treatment group (OR = 7.38, 95% CI 2.00-27.25, I² = 0%, P = .003; quality rating: very low). Additionally, DPP-4i treatment was associated with an increased overall risk of developing skin-related AEs (OR = 1.22, 95% CI 1.02-1.46, I² = 32%, P = .03; quality rating: moderate).

CONCLUSIONS

This meta-analysis suggested that treatment with DPP-4is, including sitagliptin, saxagliptin, and linagliptin, was associated with an increased risk of developing BP. Additionally, the risk of developing skin-related AEs increased when all DPP-4is were combined. Skin lesion, especially BP, should be monitored in patients with diabetes undergoing DPP-4i treatment. Future studies should evaluate the susceptible population and develop strategies for early detection of skin-related AEs.

Dipeptidyl peptidase-4 inhibitors may accelerate cirrhosis decompensation in patients with diabetes and liver cirrhosis: a nationwide population-based cohort study in Taiwan

BACKGROUND/PURPOSE

Management of type 2 diabetes mellitus (T2DM) in patients with liver cirrhosis is complex and suboptimal, but no clinical trial has adequately investigated antidiabetic drug use for such patients. We evaluate the risk of mortality, cardiovascular events, and hepatic outcomes between dipeptidyl peptidase-4 (DPP-4) inhibitor users and nonusers in patients with type 2 diabetes mellitus (T2DM) and cirrhosis.

METHODS

We selected 2828 paired propensity score matched DPP-4 inhibitor users and nonusers from a cohort of T2DM with compensated liver cirrhosis between January 1, 2007, and December 31, 2012. Cox proportional hazards models were used to assess the risk of main outcomes for DPP-4 inhibitor users.

RESULTS

The incidence rate of decompensated cirrhosis during follow-up was 2.20 and 1.53 per 100 patient-years (adjusted hazard ratio [aHR] 1.35, 95% confidence interval [CI] 1.03-1.77) for DPP-4 inhibitor users and nonusers, respectively. The aHRs (95% CI) of variceal bleeding and hepatic failure were 1.67 (1.11-2.52) and 1.35 (1.02-1.79), respectively, for DPP-4 inhibitor users over nonusers. The risk of all-cause mortality, hepatocellular carcinoma, and major cardiovascular events between DPP-4 inhibitor users and nonusers were not statistically different.

CONCLUSIONS

This study found that DPP-4 inhibitor users were associated with higher risks of decompensated cirrhosis and hepatic failure than did nonusers among patients with T2DM and compensated liver cirrhosis. We must continue to search for appropriate antidiabetic drugs for patients with liver cirrhosis.

Dipeptidyl peptidase 4 inhibitors in the treatment of type 2 diabetes mellitus

Dipeptidyl peptidase 4 inhibitors (DPP4i) have been available for treating type 2 diabetes mellitus since 2006. Although they are a diverse group, DPP4i are all small, orally available molecules that interact with the catalytic site of DPP4 without disturbing any of its other known functions, including its effects on the immune system. DPP4i have no intrinsic glucose-lowering activity, so their efficacy as anti-diabetic agents is related directly to their ability to inhibit DPP4 activity and is mediated through the effects of the substrates they protect. Of these, the incretin hormone, glucagon-like peptide 1, is probably the most important. As the effects of glucagon-like peptide 1 are glucose-dependent, the risk of hypoglycaemia with DPP4i is low. Class effects, which are directly related to the mechanism of action, are common to all DPP4i; these include their overall good safety profile and tolerability, as well as their efficacy in improving glycaemic control, but also, potentially, a small increased risk of acute pancreatitis. Compound-specific effects are those related to their differing chemistries and/or pharmacokinetic profiles. These compound-specific effects could affect the way in which individual DPP4i are used therapeutically and potentially explain off-target adverse effects, such as hospitalization for heart failure, which is seen only with one DPP4i. Overall, DPP4i have a favourable therapeutic profile and are safe and effective in the majority of patients with type 2 diabetes mellitus.

Vildagliptin, a DPP-4 inhibitor, attenuates carbon tetrachloride-induced liver fibrosis by targeting ERK1/2, p38α, and NF-κB signaling

Mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-ĸB signaling have been recognized for their causal connection with liver fibrosis. Hence, it is encouraging to discover drugs that can modify the interactions between these signaling cascades. It has been suggested that glucagon-like peptide-1 receptors (GLP-1Rs) might have a role in the observed hepatoprotection of dipeptidyl peptidase-4 inhibitors other than vildagliptin (VLD). Consequently, we aimed to elucidate the mechanisms underlying its potential antifibrotic activity in a CCl₄-intoxicated mouse model. VLD increased the percentage of viable CCl₄-intoxicated primary rat hepatocytes in vitro. It also attenuated hepatic fibrosis, improved liver function, and prolonged survival of CCl₄-intoxicated mice in a dose-dependent manner. This hepatoprotection might be mediated mainly through interference with extracellular signal-regulated protein kinase 1/2 phosphorylation, the most downstream signal of the MAPK pathway. In addition, VLD hepatoprotective activity could be partially mediated through inhibition of p38α phosphorylation and phosphorylation-induced NF-ĸB activation. As a result, VLD downregulated profibrogenic mediators, such as tumor necrosis factor α, transforming growth factor β, tissue inhibitor of metalloproteinase 1 and platelet-derived growth factor BB. Consequently, decreased expression levels of fibrosis markers, such as hydroxyproline and α smooth muscle actin, were confirmed. VLD showed a strong trend toward increasing the antioxidant defense machinery of fibrotic tissue, and we confirmed that GLP-1Rs were not implicated in the observed hepatoprotection. Since VLD poses little risk of hypoglycemia and is a safe drug for patients with liver injury, it may be a hopeful candidate for adjuvant treatment of liver fibrosis in humans.

Association between dipeptidyl peptidase-4 inhibitor and aspiration pneumonia: disproportionality analysis using the spontaneous reporting system in Japan

PURPOSE

Dipeptidyl peptidase-4 inhibitor (DPP-4-Is), a kind of drug used for the treatment of diabetes, is considered to prevent the degradation of substance P that suppresses the occurrence of dysphagia. On the other hand, DPP-4 inhibitors are also known to act on the immune system. In this study, we used a spontaneous reporting system to evaluate the signals for dysphagia and aspiration pneumonia with DPP-4-Is.

METHODS

We calculated reporting odds ratio (ROR) and information coefficients (IC) as disproportionality analysis to evaluate DPP-4-Is induced dysphagia and aspiration pneumonia using the Japanese Adverse Drug Event Report (JADER) database.

RESULTS

For DPP-4-Is as a class, no signals were detected for dysphagia, but the signal for aspiration pneumonia was detected at ROR 1.67 (95% confidence interval [95% CI]: 1.20 to 2.34) and IC 0.70 (95% CI: 0.21 to 1.19). For aspiration pneumonia, trelagliptin was the only drug among the DPP-4-Is for which both ROR and IC signals were detected (ROR 9.99, 95% CI: 4.10 to 24.36; IC: 1.98, 95% CI: 0.78 to 3.18). ROR signals, but not IC signals, were detected for linagliptin (ROR 2.66, 95% CI: 1.19 to 5.94; IC: 1.09, 95% CI: - 0.004 to 2.19) and sitagliptin (ROR 1.84, 95% CI: 1.04 to 3.25; IC: 0.78, 95% CI: - 0.03 to 1.58).

CONCLUSION

Since DPP-4 inhibitors prevent the degradation of substance P involved in swallowing reflex, DPP-4 inhibitors were expected to prevent dysphagia and aspiration pneumonia. However, this study revealed that DPP-4 inhibitors strongly were associated with onset rather than preventing aspiration pneumonia. This result suggests that DPP-4 inhibitors may affect the immune function associated with the development of aspiration pneumonia. Furthermore, there is a possibility that the amount of DPP-4-Is used clinically cannot increase the amount of substance P in sufficient quantity to prevent aspiration pneumonia.

Antidiabetic agents in patients with hepatic impairment

Chronic liver disease (CLD) often coexists with type 2 diabetes mellitus, making diabetes management a challenge to the clinician. It is well known that liver is the major site of drug metabolism, and, therefore, its impairment affects hepatic metabolism of many antidiabetic agents. Furthermore, patients with CLD have serious comorbidities such as impaired renal function, hypoalbuminemia, lactic acidosis, hypoglycemia and malnutrition, making their treatment even more difficult. On the other hand, most of the antidiabetic agents, with the exception of insulin, need dosage titration due to alterations to their pharmacokinetics in patients with CLD. For well-established antidiabetic treatments, like metformin and sulfonylureas there are studies regarding their dosage chance in these patients. However, despite the growing problem of management of diabetes in patients with CLD the existing literature data, especially on newer antidiabetic agents, are limited and, furthermore, no direct guidelines exist. Therefore, in the present review article we try to summarize the existing literature data regarding management of diabetes in patients with CLD.

Identification of a Novel Scaffold for Inhibition of Dipeptidyl Peptidase-4

Dipeptidyl peptidase-4 (DPP-4) is considered a major drug target for type 2 diabetes mellitus (T2DM). In addition to T2DM, a regulatory role of DPP-4 was also found in cardiovascular diseases. Existing DPP-4 inhibitors have been reported to have several adverse effects. In this study, a computer-aided drug design approach and its use to detect a novel class of inhibitor for DPP-4 are reported. Through structure and pharmacophore-based screening, we identified 13 hit compounds from an ∼4-million-compound library. Physical interactions of these hits with DPP-4 were studied using docking and explicit solvent molecular dynamics (MD) simulations. Later, MMPBSA binding energy was calculated for the ligand/protein simulation trajectories to determine the stability of compounds in the binding cavity. These compounds have a novel scaffold and exhibited a stable binding mode. "Best-in-screen" compounds (or their closest available analogs) were resourced and their inhibition of DPP-4 activity was experimentally validated using an in vitro enzyme activity assay in the presence of 100 and 10 μM compounds. These assays identified a compound with a spirochromanone center with 53% inhibition activity at a 100 μM concentration. A further five spirochromanone compounds were synthesized and examined in silico and in vitro; again, one compound showed 53% inhibitory activity action at 100 μM. Overall, this study identified two novel "spirochromanone" compounds that lowered DPP-4 activity by more than ∼50% at 100 μM. This study also showed the impact of fast in silico drug design techniques utilizing virtual screening and MD to identify novel scaffolds to bind and inhibit DPP-4. Spirochromanone motif identified here may be used to design molecules to achieve drug-like inhibitory action against DPP-4.

The Role of DPP-4 Inhibitors in the Treatment Algorithm of Type 2 Diabetes Mellitus: When to Select, What to Expect

Type 2 diabetes mellitus is a growing global public health problem, the prevalence of which is projected to increase in the succeeding decades. It is potentially associated with many complications, affecting multiple organs and causing a huge burden to the society. Due to its multi-factorial pathophysiology, its treatment is varied and based upon a multitude of pharmacologic agents aiming to tackle the many aspects of the disease pathophysiology (increasing insulin availability [either through direct insulin administration or through agents that promote insulin secretion], improving sensitivity to insulin, delaying the delivery and absorption of carbohydrates from the gastrointestinal tract, or increasing urinary glucose excretion). DPP-4 (dipeptidyl peptidase-4) inhibitors (or “gliptins”) represent a class of oral anti-hyperglycemic agents that inhibit the enzyme DPP-4, thus augmenting the biological activity of the “incretin” hormones (glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]) and restoring many of the pathophysiological problems of diabetes. They have already been used over more than a decade in the treatment of the disease. The current manuscript will review the mechanism of action, therapeutic utility, and the role of DPP-4 inhibitors for the treatment of type 2 diabetes mellitus.

Association between vildagliptin and risk of angioedema, foot ulcers, skin lesions, hepatic toxicity, and serious infections in patients with type 2 diabetes mellitus: A European multidatabase, noninterventional, postauthorization safety study

OBJECTIVES

This noninterventional, multidatabase, analytical cohort study explored whether vildagliptin is associated with an increased risk of specific safety events of interest, namely angioedema, foot ulcers, or skin lesions, adverse hepatic events, or serious infections compared with other noninsulin antidiabetic drugs (NIADs) using real-world data from five European electronic healthcare databases.

DESIGN

Patients with type 2 diabetes mellitus aged ≥18 years on NIAD treatment were included between January 2005 and June 2014. Adjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for the outcomes of interest were estimated using negative binomial regression.

PATIENTS

Approximately 2.8% of the included patients (n = 738 054) used vildagliptin at any time during the study, with an average follow-up time of 1.4 years.

RESULTS

The adjusted IRRs (vildagliptin vs. other NIADs) were in the range of 0.87-3.71 (angioedema), 0.73-1.19 (foot ulcers), 0.37-1.18 (skin lesions), 0.24-1.14 (composite of foot ulcer or skin lesions), 0.29-0.55 (serious hepatic events), and 0.59-1.04 (serious infections), with no lower bound of the 95% CIs > 1.

CONCLUSIONS

Overall, there was no increased risk of the events of interest in association with vildagliptin use compared with other NIADs.

Identification of Novel Metabolites of Vildagliptin in Rats: Thiazoline-Containing Thiol Adducts Formed via Cysteine or Glutathione Conjugation

Vildagliptin (VG), a dipeptidyl peptidase-4 inhibitor, is used for treating type 2 diabetes. On rare occasions, VG causes liver injury as an adverse reaction. One case report suggested the involvement of immune responses in the hepatotoxicity, but the underlying mechanisms are unknown. We recently reported that VG binds covalently in vitro to l-cysteine to produce a thiazoline acid metabolite, M407, implying that the covalent binding may trigger the immune-mediated hepatotoxicity. There was no evidence, however, that such a thiazoline acid metabolite was formed in vivo. In the present study, we administered a single oral dose of VG to male Sprague-Dawley rats, and detected M407 in plasma. The sum of urinary and fecal excretions of M407 reached approximately 2% of the dose 48 hours postdosing. Using bile duct-cannulated rats, we demonstrated that M407 was secreted into bile as a glucuronide, designated as M583. Another newly identified thiazoline metabolite of VG, the cysteinylglycine conjugate M464, was detected in urine, feces, and bile. The formation of M464 was confirmed by in vitro incubation of VG with glutathione even in the absence of metabolic enzymes. A glutathione adduct against the nitrile moiety M611 was also detected in vitro but not in vivo. In summary, we found three new thiazoline-containing thiol adduct metabolites in VG-administered rats. Nonenzymatic covalent binding of VG would likely occur in humans, and it may be relevant to predicting adverse reactions.

Comprehensive Evaluation of Combination Therapy with Basal Insulin and Either Lixisenatide or Vildagliptin in Japanese Patients with Type 2 Diabetes: A Randomized, Open-Label, Parallel-Group, Multicenter Study

INTRODUCTION

We comprehensively evaluated the effects of combination therapy with insulin glargine and the incretin-based drugs lixisenatide or vildagliptin in Japanese patients with type 2 diabetes.

METHODS

In this 12-week, randomized, open-label, parallel-group, multicenter study (GLP-ONE Kobe), the incretin-based drug sitagliptin was randomly switched to lixisenatide (20 μg/day, n = 18) or vildagliptin (100 mg/day, n = 20) in patients with inadequate glycemic control despite combination therapy with insulin glargine and sitagliptin. The dose of insulin glargine was titrated after the switch to maintain fasting blood glucose at approximately 110 mg/dL. The primary end points of the study were the change in glycosylated hemoglobin (HbA_1c) level between before and 12 weeks after the treatment switch, the proportion of patients achieving an HbA_1c level below 7.0%, and the postprandial increase in glucose concentration as assessed by self-monitoring of blood glucose.

RESULTS

The change in HbA_1c level from baseline to 12 weeks did not differ significantly between the lixisenatide and vildagliptin groups (- 0.6 ± 0.7% and - 0.6 ± 1.2%, respectively, P = 0.920). Neither the proportion of patients achieving an HbA_1c level below 7.0% nor the postprandial increase in glucose concentration was different between two groups. Body weight and serum low density lipoprotein (LDL) cholesterol level decreased significantly in the lixisenatide and vildagliptin groups, respectively. Both drugs were associated with mild gastrointestinal symptoms but not with severe hypoglycemia. Vildagliptin was associated with elevation of serum aspartate transaminase. Treatment satisfaction as assessed with the Diabetes Treatment Satisfaction Questionnaire did not differ significantly between the two groups.

CONCLUSION

The combinations of basal insulin and either lixisenatide or vildagliptin have similar efficacies with regard to improvement of glycemic control.

TRIAL REGISTRATION

This trial has been registered with UMIN (No. 000010769).

Identification of a novel metabolite of vildagliptin in humans: Cysteine targets the nitrile moiety to form a thiazoline ring

The dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin (VG) is used to treat type 2 diabetes. In rare cases, VG-induced liver injury has been reported. One case report suggested that immune responses were involved in the hepatotoxicity. However, the underlying mechanisms of VG-induced hepatotoxicity are uncertain. In the present study, we investigated whether VG has the potential to covalently bind to macromolecules in cells, a process that could initiate immune-mediated hepatotoxicity. For comparison, M20.7, a major metabolite of VG, and other DPP-4 inhibitors were also evaluated. We found that VG and anagliptin (ANG), which both contain a cyanopyrrolidine moiety, rapidly reacted in non-enzymatic manners on co-incubation with l-cysteine. Both VG and ANG had half-lives of 20-30 min. In contrast, incubation with GSH, rather than l-cysteine, failed to decrease the concentrations of VG or ANG. M20.7, sitagliptin, linagliptin, and alogliptin, having no cyanopyrrolidine moiety, were stable on incubation with l-cysteine or GSH. Structural analysis of the VG- and ANG-cysteine adducts, designated M407 and M487, respectively, revealed that the nitrile moieties of VG and ANG were irreversibly converted to a thiazoline acid. In conclusion, we found that VG and ANG have the potential to covalently bind to a thiol residue of l-cysteine in proteins. Such binding may lead to unpredictable immune responses in humans. l-Cysteine, rather than GSH, would likely be useful to detect the potential for covalent binding that could initiate immune-mediated hepatotoxicity.

Vildagliptin loaded triangular DNA nanospheres coated with eudragit for oral delivery and better glycemic control in type 2 diabetes mellitus

Diabetes mellitus type 2 is a multidimensional disease associated with poor glycemic control through compromised sensitivity of pancreatic islet α and β cells against glucose and dwindled secretion of insulin which is linked with the quantity of incretin hormones that are abridged by dipeptidyl peptidase-4 (DPP-4) in diseased condition. Vildagliptin (VG) inhibits DPP-4 therefore regulates the incretins that conversely maintains glycemic control. The safe reach and absorption of VG from intestine was dubious. Therefore we used Electrostatic Attraction Method to develop drug loaded DNA nanotechnology triangles coated by Eudragit (Eud) to make stable nanospheres of Vildagliptin (VG). We further analyzed the formulated nanospheres by AFM, XRD, DSC, SEM, TGA, ATR-FTIR and native PAGE. Additionally the efficacy of formulated nanospheres for drug release and glycemic control was assessed in Db/Db mouse. Our results showed that formulated nanospheres are smooth, spherical, stable and uniform in size ranging from 500 to 2000 nm with drug entrapment efficiency up to 95 ± 2% and extended drug release up to 15 ± 2 h. FTIR and DSC results confirmed the absence of VG-DNA-Eud interaction and XRD studies revealed a change in the crystalline status of the VG in nanospheres. Ex-vivo studies indicate that Eud-DNA-VG nanospheres effectively bypasses the acidic pH of the stomach and enhances glycemic control in Db/Db mouse without any risk of pancreatitis or pancreatic cancer. To the best of our knowledge, this is the first study conclusively reporting that VG loaded DNA Nano-architects coated with Eudragit are stable, safe and may improve therapeutic outcomes after oral delivery.

Clinical Safety and Tolerability of Vildagliptin - Insights from Randomised Trials, Observational Studies and Post-marketing Surveillance

Vildagliptin is one of the most extensively studied dipeptidyl peptidase-4 (DPP-4) inhibitors in terms of its clinical utility. Over the last decade, a vast panorama of evidence on the benefit-risk profile of vildagliptin has been generated in patients with type 2 diabetes mellitus (T2DM). In this article, we review the cumulative evidence on the safety of vildagliptin from the clinical development programme, as well as reports of rare adverse drug reactions detected during the post-marketing surveillance of the drug. Across clinical studies, the overall safety and tolerability profile of vildagliptin was similar to placebo, and it was supported by real-world data in a broad population of patients with T2DM, making DPP-4 inhibitors, like vildagliptin, a safe option for managing patients with T2DM.

Consensus Statement on Dose Modifications of Antidiabetic Agents in Patients with Hepatic Impairment

Liver disease is an important cause of mortality in type 2 diabetes mellitus (T2DM). It is estimated that diabetes is the most common cause of liver disease in the United States. Virtually, entire spectrum of liver disease is seen in T2DM including abnormal liver enzymes, nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, and acute liver failure. The treatment of diabetes mellitus (DM) in cirrhotic patients has particular challenges as follows: (1) about half the patients have malnutrition; (2) patients already have advanced liver disease when clinical DM is diagnosed; (3) most of the oral antidiabetic agents (ADAs) are metabolized in the liver; (4) patients often have episodes of hypoglycemia. The aim of this consensus group convened during the National Insulin Summit 2015, Puducherry, was to focus on the challenges with glycemic management, with particular emphasis to safety of ADAs across stages of liver dysfunction. Published literature, product labels, and major clinical guidelines were reviewed and summarized. The drug classes included are biguanides (metformin), the second- or third-generation sulfonylureas, alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and currently available insulins. Consensus recommendations have been drafted for glycemic targets and dose modifications of all ADAs. These can aid clinicians in managing patients with diabetes and liver disease.

Drug Hepatotoxicity: Newer Agents

Idiosyncratic hepatotoxicity is one of the most common reasons for an approved drug being restricted. This article focuses on hepatotoxicity of selected and recently introduced agents, such as, tyrosine kinase inhibitors, monoclonal antibodies, novel oral anticoagulants, newer antiplatelets, antibiotics, anti-diabetics, anti-epileptics, anti-depressants, anti-psychotics and anti-retrovirals. Overall, the incidence of clinically relevant hepatotoxicity from newer agents seems to be lower than that of the older agents. Nevertheless, cases of severe hepatotoxicity have been reported due to some of these newer agents, including, trastuzumab, ipilimumab, infliximab, imatinib, bosutinib, dasatinib, gefitinib, erlotinib, sunitinib, ponatinib, lapatinib, vemurafenib, dabigatran, rivaroxaban, felbamate, lamotrigine, levetiracetam, venlafaxine, duloxetine, darunavir, and maraviroc.

Diabetes mellitus and the skin

Diabetes is a debilitating, life-threatening disease accounting in 2015 for the death of 5 million people worldwide. According to new estimations, 415 million adults currently suffer from the disease, and this number is expected to rise to 642 million by 2040. High glucose blood levels also affect the skin among systemic organs, and skin disorders can often predict the onset of this metabolic disorder. In this review, we address the pathomechanistic effects of diabetes on the skin and give an overview on the most common skin diseases associated with diabetes.

DPP-4 inhibitors and risk of infections: a meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the risk of infections in the treatment of type 2 diabetes patients with dipeptidyl-peptidase 4 (DPP-4) inhibitors.

METHODS

A literature search was conducted through electronic databases. The inclusion criteria included study duration of no less than 12 weeks developed in type 2 diabetes patients, the use of a randomized control group receiving a DPP-4 inhibitor and the availability of outcome data for infections. Out of 2181 studies, 74 studies were finally included.

RESULTS

The risk of overall infection for DPP-4 inhibitors treatment was comparable to placebo (odds ratio (OR) = 0.97, 95% confidence interval (CI), 0.91 to 1.04, p = 0.40), metformin treatment (OR = 1.22, 95% CI, 0.95 to 1.56, p = 0.12), sulphonylurea treatment (OR = 1.09, 0.93 to 1.29, p = 0.29), thiazolidinedione treatment (OR = 0.86, 95% CI, 0.65 to 1.14, p = 0.29) and alpha glucosidase inhibitor treatment (OR = 1.03, 95% CI, 0.33 to 3.22, p = 0.96). When compared different DPP-4 inhibitors with placebo treatment, risks of infections were comparable for alogliptin, linagliptin, sitagliptin, saxagliptin and vildagliptin. Compared with placebo or active comparator treatment, risks of infection in different systems for DPP-4 inhibitors were all comparable.

CONCLUSIONS

The overall risk of infections of DPP-4 inhibitor was not increased compared with control groups.

Dipeptidyl peptidase-4 inhibition in chronic kidney disease and potential for protection against diabetes-related renal injury

AIMS

Type 2 diabetes mellitus (T2DM) is associated with a high risk of chronic kidney disease (CKD). About 20% of patients with T2DM have CKD of stage ≥ 3; up to 40% have some degree of CKD. Beyond targeting all renal risk factors together, renin-angiotensin-aldosterone system blockers are to date the only effective mainstay for the treatment of diabetic kidney disease (DKD). Indeed, several potentially nephroprotective agents have been in use, which have been unsuccessful. Some glucose-lowering agents, including dipeptidyl peptidase-4 inhibitors (DPP-4i), have shown promising results. Here, we discuss the evidence that glucose lowering with DPP-4i may be an option for protecting against diabetes-related renal injury.

DATA SYNTHESIS

A comprehensive search was performed of the literature using the terms "alogliptin," "linagliptin," "saxagliptin," "sitagliptin," and "vildagliptin" for original articles and reviews addressing this topic. DPP-4i are an effective, well-tolerated treatment option for T2DM with any degree of renal impairment. Preclinical observations and clinical studies suggest that DPP-4i might also be a promising strategy for the treatment of DKD. The available data are in favor of saxagliptin and linagliptin, but the consistency of results points to the possible nephroprotective effect of DPP-4i. This property appears to be independent of glucose lowering and can potentially complement other therapies that preserve renal function. Larger prospective clinical trials are ongoing, which might strengthen these hypothesis-generating findings.

CONCLUSIONS

The improvement in albuminuria associated with DPP-4i suggests that these agents may provide renal benefits beyond their glucose-lowering effects, thus offering direct protection from DKD. These promising results must be interpreted with caution and need to be confirmed in forthcoming studies.

Comparative review of dipeptidyl peptidase-4 inhibitors and sulphonylureas

Type 2 diabetes (T2DM) is a progressive disease, and pharmacotherapy with a single agent does not generally provide durable glycaemic control over the long term. Sulphonylurea (SU) drugs have a history stretching back over 60 years, and have traditionally been the mainstay choice as second-line agents to be added to metformin once glycaemic control with metformin monotherapy deteriorates; however, they are associated with undesirable side effects, including increased hypoglycaemia risk and weight gain. Dipeptidyl peptidase (DPP)-4 inhibitors are, by comparison, more recent, with the first compound being launched in 2006, but the class now globally encompasses at least 11 different compounds. DPP-4 inhibitors improve glycaemic control with similar efficacy to SUs, but do not usually provoke hypoglycaemia or weight gain, are relatively free from adverse side effects, and have recently been shown not to increase cardiovascular risk in large prospective safety trials. Because of these factors, DPP-4 inhibitors have become an established therapy for T2DM and are increasingly being positioned earlier in treatment algorithms. The present article reviews these two classes of oral antidiabetic drugs (DPP-4 inhibitors and SUs), highlighting differences and similarities between members of the same class, as well as discussing the potential advantages and disadvantages of the two drug classes. While both classes have their merits, the choice of which to use depends on the characteristics of each individual patient; however, for the majority of patients, DPP-4 inhibitors are now the preferred choice.

Incretin therapies: highlighting common features and differences in the modes of action of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors

Over the last few years, incretin-based therapies have emerged as important agents in the treatment of type 2 diabetes (T2D). These agents exert their effect via the incretin system, specifically targeting the receptor for the incretin hormone glucagon-like peptide 1 (GLP-1), which is partly responsible for augmenting glucose-dependent insulin secretion in response to nutrient intake (the 'incretin effect'). In patients with T2D, pharmacological doses/concentrations of GLP-1 can compensate for the inability of diabetic β cells to respond to the main incretin hormone glucose-dependent insulinotropic polypeptide, and this is therefore a suitable parent compound for incretin-based glucose-lowering medications. Two classes of incretin-based therapies are available: GLP-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1RAs promote GLP-1 receptor (GLP-1R) signalling by providing GLP-1R stimulation through 'incretin mimetics' circulating at pharmacological concentrations, whereas DPP-4 inhibitors prevent the degradation of endogenously released GLP-1. Both agents produce reductions in plasma glucose and, as a result of their glucose-dependent mode of action, this is associated with low rates of hypoglycaemia; however, there are distinct modes of action resulting in differing efficacy and tolerability profiles. Furthermore, as their actions are not restricted to stimulating insulin secretion, these agents have also been associated with additional non-glycaemic benefits such as weight loss, improvements in β-cell function and cardiovascular risk markers. These attributes have made incretin therapies attractive treatments for the management of T2D and have presented physicians with an opportunity to tailor treatment plans. This review endeavours to outline the commonalities and differences among incretin-based therapies and to provide guidance regarding agents most suitable for treating T2D in individual patients.

Comparison of vildagliptin and sitagliptin in patients with type 2 diabetes and severe renal impairment: a randomised clinical trial

AIMS/HYPOTHESIS

There are limited data comparing dipeptidyl peptidase-4 (DPP-4) inhibitors directly. We compared the safety and efficacy of vildagliptin and sitagliptin in patients with type 2 diabetes and severe renal impairment (RI).

METHODS

This study was a parallel-arm, randomised, multicentre, double-blind, 24 week study conducted in 87 centres across Brazil and the USA. Patients with type 2 diabetes, either drug naive or treated with any glucose-lowering agents, who had inadequate glycaemic control (HbA1c 6.5-10.0% [48-86 mmol/mol]) and an estimated GFR <30 ml min(-1) [1.73 m](-2) were randomised (via interactive voice response technology) to vildagliptin 50 mg once daily or sitagliptin 25 mg once daily. These doses are recommended in this patient population and considered maximally effective. Participants, investigators and the sponsor were blinded to group assignment. Efficacy endpoints included change in HbA1c and fasting plasma glucose (FPG) at all visits and the primary safety endpoint was assessment of treatment-emergent adverse events.

RESULTS

In total, 148 patients were randomised, 83 to vildagliptin and 65 to sitagliptin. All patients were analysed. After 24 weeks, the adjusted mean change in HbA1c was -0.54% (5.9 mmol/mol) from a baseline of 7.52% (59 mmol/mol) with vildagliptin and -0.56% (6.1 mmol/mol) from a baseline of 7.80% (62 mmol/mol) with sitagliptin (p = 0.874). FPG decreased by 0.47 ± 0.37 mmol/l with vildagliptin and increased by 0.16 ± 0.43 mmol/l with sitagliptin (p = 0.185). Both treatments were well tolerated with overall similar safety profiles.

CONCLUSIONS/INTERPRETATION

At their recommended doses for severe RI, vildagliptin (50 mg once daily) compared with sitagliptin (25 mg once daily) demonstrated similar efficacy and both drugs were well tolerated. This study provides further support for the use of DPP-4 inhibitors in patients with severe RI.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00616811 (completed)

FUNDING

This study was planned and conducted by Novartis.

Pharmacokinetics and clinical use of incretin-based therapies in patients with chronic kidney disease and type 2 diabetes

The prevalence of chronic kidney disease (CKD) of stages 3-5 (glomerular filtration rate [GFR] <60 mL/min) is about 25-30 % in patients with type 2 diabetes mellitus (T2DM). While most oral antidiabetic agents have limitations in patients with CKD, incretin-based therapies are increasingly used for the management of T2DM. This review analyses (1) the influence of CKD on the pharmacokinetics of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists; and (2) the efficacy/safety profile of these agents in clinical practice when prescribed in patients with both T2DM and CKD. Most DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin) are predominantly excreted by the kidneys. Thereby, pharmacokinetic studies showed that total exposure to the drug is increased in proportion to the decline of GFR, leading to recommendations for appropriate dose reductions according to the severity of CKD. In these conditions, clinical studies reported a good efficacy and safety profile in patients with CKD. In contrast, linagliptin is eliminated by a predominantly hepatobiliary route. As a pharmacokinetic study showed only minimal influence of decreased GFR on total exposure, no dose adjustment of linagliptin is required in the case of CKD. The experience with GLP-1 receptor agonists in patients with CKD is more limited. Exenatide is eliminated by renal mechanisms and should not be given in patients with severe CKD. Liraglutide is not eliminated by the kidney, but it should be used with caution because of the limited experience in patients with CKD. Only limited pharmacokinetic data are also available for lixisenatide, exenatide long-acting release (LAR) and other once-weekly GLP-1 receptor agonists in current development. Several case reports of acute renal failure have been described with GLP-1 receptor agonists, probably triggered by dehydration resulting from gastrointestinal adverse events. However, increasing GLP-1 may also exert favourable renal effects that could contribute to reducing the risk of diabetic nephropathy. In conclusion, the already large reassuring experience with DPP-4 inhibitors in patients with CKD offers new opportunities to the clinician, whereas more caution is required with GLP-1 receptor agonists because of the limited experience in this population.

Diabetes therapies in hemodialysis patients: Dipeptidase-4 inhibitors

Although several previous studies have been published on the effects of dipeptidase-4 (DPP-4) inhibitors in diabetic hemodialysis (HD) patients, the findings have yet to be reviewed comprehensively. Eyesight failure caused by diabetic retinopathy and aging-related dementia make multiple daily insulin injections difficult for HD patients. Therefore, we reviewed the effects of DPP-4 inhibitors with a focus on oral antidiabetic drugs as a new treatment strategy in HD patients with diabetes. The following 7 DPP-4 inhibitors are available worldwide: sitagliptin, vildagliptin, alogliptin, linagliptin, teneligliptin, anagliptin, and saxagliptin. All of these are administered once daily with dose adjustments in HD patients. Four types of oral antidiabetic drugs can be administered for combination oral therapy with DPP-4 inhibitors, including sulfonylureas, meglitinide, thiazolidinediones, and alpha-glucosidase inhibitor. Nine studies examined the antidiabetic effects in HD patients. Treatments decreased hemoglobin A1c and glycated albumin levels by 0.3% to 1.3% and 1.7% to 4.9%, respectively. The efficacy of DPP-4 inhibitor treatment is high among HD patients, and no patients exhibited significant severe adverse effects such as hypoglycemia and liver dysfunction. DPP-4 inhibitors are key drugs in new treatment strategies for HD patients with diabetes and with limited choices for diabetes treatment.

Pharmacokinetics in patients with chronic liver disease and hepatic safety of incretin-based therapies for the management of type 2 diabetes mellitus

Patients with type 2 diabetes mellitus have an increased risk of chronic liver disease (CLD) such as non-alcoholic fatty liver disease and steatohepatitis, and about one-third of cirrhotic patients have diabetes. However, the use of several antidiabetic agents, such as metformin and sulphonylureas, may be a concern in case of hepatic impairment (HI). New glucose-lowering agents targeting the incretin system are increasingly used for the management of type 2 diabetes. Incretin-based therapies comprise oral inhibitors of dipeptidyl peptidase-4 (DPP-4) (gliptins) or injectable glucagon-like peptide-1 (GLP-1) receptor agonists. This narrative review summarises the available data regarding the use of both incretin-based therapies in patients with HI. In contrast to old glucose-lowering agents, they were evaluated in specifically designed acute pharmacokinetic studies in patients with various degrees of HI and their hepatic safety was carefully analysed in large clinical trials. Only mild changes in pharmacokinetic characteristics of DPP-4 inhibitors were observed in patients with different degrees of HI, presumably without major clinical relevance. GLP-1 receptor agonists have a renal excretion rather than liver metabolism. Specific pharmacokinetic data in patients with HI are only available for liraglutide. No significant changes in liver enzymes were reported with DPP-4 inhibitors or GLP-1 receptor agonists, alone or in combination with various other glucose-lowering agents, in clinical trials up to 2 years in length. On the contrary, preliminary data suggested that incretin-based therapies may be beneficial in patients with CLD, more particularly in the presence of non-alcoholic fatty liver disease. Nevertheless, caution should be recommended, especially in patients with advanced cirrhosis, because of a lack of clinical experience with incretin-based therapies in these vulnerable patients.

Real-life safety and efficacy of vildagliptin as add-on to metformin in patients with type 2 diabetes in Turkey--GALATA study

OBJECTIVE

To evaluate tolerability/safety and the efficacy of the combination of vildagliptin plus metformin in a real-life population of patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

This multicenter, single-arm, 6 month, observational, prospective cohort study was conducted at 39 centers across Turkey. T2DM patients on vildagliptin and metformin for ≤4 weeks were enrolled regardless of their previous antidiabetic therapy.

MAIN OUTCOME MEASURES

Efficacy was evaluated by measuring hemoglobin A1c (HbA1c) levels. Tolerability/safety parameters evaluated included hypoglycemic events, gastrointestinal events, peripheral edema and weight gain.

RESULTS

This study enrolled 665 patients with a mean ± standard deviation (SD) age of 55.1 ± 10.2 years and female predominance (n = 394, 59.2%). Safety was assessed in all enrolled patients. Hypoglycemia was reported in 10 (1.5%) patients (95% confidence interval = 0.8-2.7%). Efficacy was assessed in 289 (43.5%) patients treated for 6 ± 1 months; these patients showed a mean decrease in HbA1c of 0.8% from baseline value of 7.8% (p < 0.001). The percentages of patients who achieved HbA1c targets of ≤6.5% and ≤7.0% were significantly increased, from 10.7% to 33.6% and from 22.1% to 52.6%, respectively (p < 0.001 each). The decrease in HbA1c was independent of baseline HbA1c (≤8% vs. 8-10% vs. ≥10%), age (≤65 vs. >65 years) and body mass index (<30 vs. ≥30 kg/m(2)) (p < 0.001 each). In total, 136 adverse events (AEs) were observed in 71 (10.7%) patients; 10 (1.5%) patients experienced hypoglycemia and gastrointestinal AEs were most commonly reported (n = 29, 4.4%).

CONCLUSIONS

In a 'real-life' setting, the vildagliptin and metformin combination was associated with significant improvements in reaching target HbA1c levels, even in elderly and obese patients with T2DM. Moreover, vildagliptin and metformin demonstrated a good overall tolerability/safety profile.

DPP-4 inhibitors: pharmacological differences and their clinical implications

INTRODUCTION

Recently, incretin-based therapy was introduced for the treatment of type 2 diabetes (T2D). In particular, dipeptidyl peptidase-4 inhibitors (DPP-4i) (sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin) play an increasing role in the management of T2D.

AREAS COVERED

An extensive literature search was performed to analyze the pharmacological characteristics of DPP-4i and their clinical implications.

EXPERT OPINION

DPP-4i present significant pharmacokinetic differences. They also differ in chemical structure, in the interaction with distinct subsites of the enzyme and in different levels of selectivity and potency of enzyme inhibition. Moreover, disparities in the effects on glycated hemoglobin, glucagon-like peptide-1 and glucagon levels and on glucose variability have been observed. However, indirect comparisons indicate that all DPP-4i have a similar safety and efficacy profiles. DPP-4i are preferred in overweight/obese and elderly patients because of the advantages of minimal or no influence on weight gain and low risk of hypoglycemia. For the same reasons, DPP-4i can be safely combined with insulin. However, currently cardiovascular outcomes related to DPP-4i are widely debated and the available evidence is controversial. Today, long-term studies are still in progress and upcoming results will allow us to better define the strengths and limits of this therapeutic class.

Effectiveness and tolerability of second-line treatment with vildagliptin versus other oral drugs for type 2 diabetes in a real-world setting in the Middle East: results from the EDGE study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic progressive disease that requires treatment intensification with antihyperglycemic agents due to progressive deterioration of β-cell function. A large observational study of 45,868 patients with T2DM across 27 countries (EDGE) assessed the effectiveness and safety of vildagliptin as add-on to other oral antidiabetic drugs (OADs) versus other comparator OAD combinations. Here, we present results from the Middle East countries (Bahrain, Jordan, Kuwait, Lebanon, Oman, Palestine, and the United Arab Emirates).

METHODS

Patients inadequately controlled with OAD monotherapy were eligible after the add-on treatment was chosen by the physician based on clinical judgment and patient need. Patients were assigned to either vildagliptin or comparator OADs (sulfonylureas, thiazolidinediones, glinides, α-glucosidase inhibitors, or metformin, except incretin-based therapies) based on the add-on therapy. The primary endpoint was the proportion of patients achieving a glycated hemoglobin (HbA1c) reduction of >0.3% without peripheral edema, hypoglycemia, discontinuation due to a gastrointestinal event, or weight gain≥5%. One of the secondary endpoints was the proportion of patients achieving HbA1c<7% without hypoglycemia or weight gain. Change in HbA1c from baseline to study endpoint and safety were also assessed.

RESULTS

Of the 4,780 patients enrolled in the Middle East, 2,513 received vildagliptin and 2,267 received other OADs. Overall, the mean (±standard deviation) age at baseline was 52.1±10.2 years, mean HbA1c was 8.5%±1.3%, and mean T2DM duration was 4.2±4.0 years. The proportion of patients achieving the primary (76.1% versus 61.6%, P<0.0001) and secondary (54.8% versus 29.9%, P<0.0001) endpoints was higher with vildagliptin than with the comparator OADs. The unadjusted odds ratios for the primary and secondary endpoints were 1.98 (95% confidence interval 1.75-2.25) and 2.8 (95% confidence interval 2.5-3.2), respectively, in favor of vildagliptin. Vildagliptin achieved a numerically greater reduction in HbA1c (1.7%) from baseline versus comparator OADs (1.4%). The overall incidence of adverse events was comparable between studied cohorts.

CONCLUSION

In real life, treatment with vildagliptin was associated with a higher proportion of patients with T2DM achieving better glycemic control without tolerability issues in the Middle East.

Safety of dipeptidyl peptidase-4 inhibitors for treating type 2 diabetes

INTRODUCTION

Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) occupy a growing place in the armamentarium of drugs used for the management of hyperglycemia in type 2 diabetes, although some safety concerns have been raised in recent years.

AREAS COVERED

An updated review providing an analysis of available safety data (meta-analyses, randomized controlled trials, observational cohort and case-control studies and pharmacovigilance reports) with five commercialized DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin, linagliptin). A special focus is given to overall safety profile; pancreatic adverse events (AEs) (acute pancreatitis, pancreatic cancer); overall cardiovascular safety (myocardial infarction and stroke); congestive heart failure concern and finally, safety in special populations (elderly, renal impairment).

EXPERT OPINION

The good tolerance/safety profile of DPP-4 inhibitors has been largely confirmed, including in more fragile populations (elderly, renal impairment) with almost no increased risk of infection or gastrointestinal AEs, no weight gain and a minimal risk of hypoglycemia. Although an increased risk of acute pancreatitis and pancreatic cancer was suspected, the complete set of available data appears reassuring so far. Cardiovascular safety of DPP-4 inhibitors has been proven but an unexpected increased risk of heart failure has been reported which should be confirmed in ongoing trials and better understood. Further postmarketing surveillance is recommended.

Overview of saxagliptin efficacy and safety in patients with type 2 diabetes and cardiovascular disease or risk factors for cardiovascular disease

Most individuals with type 2 diabetes mellitus have or will develop multiple independent risk factors for cardiovascular disease, particularly coronary artery disease (CAD). CAD is the leading cause of morbidity and mortality among individuals with type 2 diabetes mellitus, and treating these patients is challenging. The risk of hypoglycemia, weight gain, or fluid retention with some diabetes medications should be considered when developing a treatment plan for individuals with a history of CAD or at risk for CAD. Dipeptidyl peptidase-4 inhibitors are oral antihyperglycemic agents that inhibit the breakdown of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, resulting in increased glucose-dependent insulin secretion and suppression of glucagon secretion. Saxagliptin is a potent and selective dipeptidyl peptidase-4 inhibitor that improves glycemic control and is generally well tolerated when used as monotherapy and as add-on therapy to other antihyperglycemic medications. This review summarizes findings from recently published post hoc analyses of saxagliptin clinical trials that have been conducted in patients with and without a history of cardiovascular disease and in patients with and without various risk factors for cardiovascular disease. The results show that saxagliptin was generally well tolerated and consistently improved glycemic control, as assessed by reductions from baseline in glycated hemoglobin, fasting plasma glucose concentration, and postprandial glucose concentration, regardless of the presence or absence of baseline cardiovascular disease, hypertension, statin use, number of cardiovascular risk factors, or high Framingham 10-year cardiovascular risk score.

Effectiveness and Tolerability of Second-Line Therapy with Vildagliptin Versus Other Oral Agents in Type 2 Diabetes (EDGE): Post Hoc Sub-Analysis of Bulgarian Data

OBJECTIVES

Metformin is an established first-line treatment for type 2 diabetes mellitus (T2DM) patients but intensification of oral anti-diabetic therapy is usually required over time. The effectiveness of diabetes control with vildaGliptin and vildagliptin/mEtformin (EDGE) study compared effectiveness and safety of vildagliptin and other oral anti-diabetic drugs (OAD) in 45,868 patients worldwide with inadequately controlled T2DM by monotherapy under real-life conditions. Here, we present effectiveness results for patients receiving vildagliptin (vildagliptin cohort) or another OAD (comparator cohort) add-on to monotherapy in Bulgaria.

METHODS

The eligible diabetes patients inadequately controlled with current monotherapy were assigned to add-on treatment, which was chosen by the physician based on patient's need. Effectiveness was assessed by glycated hemoglobin (HbA1c) drop and by means of a composite endpoint assessing the proportion of patients responding to treatment (HbA1c <7%) without proven hypoglycemic event and significant weight gain (>5%) after 12 months of treatment.

RESULTS

In total, 754 patients were enrolled in Bulgaria, 384 in the vildagliptin cohort and 369 in the comparator cohort. Mean HbA1c change from baseline was significantly higher with vildagliptin compared to the comparator (-1.35% in the vildagliptin cohort and -0.55% in the comparator cohort, P < 0.001). In the vildagliptin cohort, a higher proportion of patients reached the composite endpoint (HbA1c <7%, no hypoglycemic events, no weight gain) when compared to the comparator cohort (vildagliptin: 32.3%; comparator: 8.4%; P < 0.001). Overall, vildagliptin was well tolerated with similarly low incidences of total adverse events (3.4% versus 1.9% in the comparator group) and serious adverse events (2.3% versus 1.1% in the comparator group).

CONCLUSIONS

In real-life clinical practice in Bulgaria, vildagliptin is associated with a greater HbA1c drop, and a higher proportion of patients reaching target HbA1c without hypoglycemia and weight gain compared to comparator.

Vildagliptin , a DPP-4 inhibitor for the twice-daily treatment of type 2 diabetes mellitus with or without metformin

INTRODUCTION

Dipeptidyl peptidase-4 inhibitors increase circulating levels of glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide regulating glucose-dependent insulin secretion. In addition, GLP-1 suppresses glucagon secretion, delays gastric emptying and increases satiety. The combination of vildagliptin with the biguanide metformin is of particular interest because of its complementary mode of action, addressing insulin resistance, alpha- and beta cell function in the islet of the pancreas.

AREAS COVERED

Because of the abundance of data supporting the use of vildagliptin alone and in combination with metformin, the present paper aims at giving an overview on the current evidence for its use in patients with type 2 diabetes mellitus.

EXPERT OPINION

The data suggest that vildagliptin offers similar glycemic control compared to sulfonylureas and thiazolidinediones, while having the benefit of being associated with fewer cases of hypoglycemia and less body weight gain. There is increasing evidence that compared with sulfonylureas, vildagliptin has favorable effects on pancreatic alpha- and beta-cell function. Vildagliptin in combination with metformin, improve glycemic control with a favorable safety and tolerability profile, making it an attractive therapeutic option in patients where metformin monotherapy alone is not sufficient.

Safety of saxagliptin: events of special interest in 9156 patients with type 2 diabetes mellitus

BACKGROUND

A post hoc pooled analysis was undertaken to evaluate the safety of saxagliptin in patients with type 2 diabetes mellitus, with attention to events of special interest for dipeptidyl peptidase-4 inhibitors.

METHODS

Pooled analyses were performed for 20 randomized controlled studies (N = 9156) of saxagliptin as monotherapy or add-on therapy, and a subset of 11 saxagliptin + metformin studies. Adverse events and events of special interest (gastrointestinal adverse events, infections, hypersensitivity, pancreatitis, skin lesions, lymphopenia, thrombocytopenia, hypoglycaemia, bone fracture, severe cutaneous adverse reactions, opportunistic infection, angioedema, malignancy, worsening renal function, and specific laboratory events) were assessed; incidence rates (events/100 person-years) and incidence rates ratios (saxagliptin/control) were calculated (Mantel-Haenszel method).

RESULTS

In both pooled datasets, the incidence rates for deaths, serious adverse events, discontinuations due to adverse events, pancreatitis, malignancy, and most other events of special interest, excepting bone fractures and hypersensitivity, were similar between treatments, with 95% confidence intervals (CIs) for incidence rates ratios including 1. In the 20-study pool, the incidence rates per 100 person-years was higher with saxagliptin versus control for bone fractures [1.1 vs 0.6; incidence rates ratio (95% CI), 1.81 (1.04-3.28)] and hypersensitivity adverse events [1.3 vs 0.8; 1.67 (1.01-2.87)].

CONCLUSIONS

Pooled data from 20 studies confirm that saxagliptin has a favourable safety and benefit-risk profile.

Dipeptidyl peptidase-4 inhibitors: pharmacokinetics, efficacy, tolerability and safety in renal impairment

The dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of blood glucose-lowering therapy with proven efficacy, tolerability and safety. Four of the five commercially available DPP-4 inhibitors are subject to significant renal clearance, and pharmacokinetic studies in people with renal impairment have led to lower recommended doses based on creatinine clearance in order to prevent drug accumulation. Data from these pharmacokinetic studies and from supratherapeutic doses in healthy individuals and people with uncomplicated diabetes during development suggest, however, that there is a wide therapeutic margin. This should protect against toxicity if people with renal impairment are inadvertently prescribed higher doses than recommended. Doses appropriate to renal function are associated with reductions in HbA1c that are equivalent to those observed in people with type 2 diabetes who do not have renal impairment. Recent large-scale cardiovascular safety trials of saxagliptin and alogliptin have identified heart failure as a potential concern and renal impairment may increase the risk of this complication. Although the incidence of pancreatitis does not appear to be significantly increased by DPP-4 inhibitor therapy, renal impairment is also an independent risk factor. Additional data from other ongoing DPP-4 inhibitor cardiovascular safety trials should provide a more precise assessment of the risks of these uncommon complications, including in people with renal impairment.

Incretin therapies in the management of patients with type 2 diabetes mellitus and renal impairment

Renal impairment (RI) is common among patients with type 2 diabetes mellitus (T2DM), and these patients also experience an age-related decline in renal function. At the same time, treatment options are more limited and treatment is more complex, particularly in patients with moderate or severe RI due to contraindications, need for dose adjustment and/or regular monitoring, and side effects, such as fluid retention and hypoglycemia, which are a more serious concern in this patient population. Incretin therapies, consisting of the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and the oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are a promising new class of antihyperglycemic drugs. In the overall population, they improve glycemic control in a glucose-dependent manner and are not likely to cause hypoglycemia, representing a clear advantage in at-risk populations. Data regarding use of these agents in renally impaired patients have started to emerge, and the objective of this article is to provide an overview of the currently available data and the potential role of these novel agents in the management of patients with T2DM and RI. Data for the GLP-1 receptor agonists in patients with moderate or severe RI are still limited, with no trials dedicated to these populations currently published. In addition, their potential to cause gastrointestinal side effects may limit use in patients with RI due to the risk of dehydration and hypovolemia. The use of GLP-1 receptor agonists in patients with moderate or severe RI is therefore, at present, underlying caution and/or restrictions. On the other hand, data from specific trials in patients with moderate or severe RI are now becoming available for most of the DPP-4 inhibitors. These studies demonstrate good efficacy and tolerability of the DPP-4 inhibitors in patients with moderate or severe RI, thus opening a place for these therapies in the treatment of populations with T2DM and RI. Several of the DPP-4 inhibitors are already approved for use in patients with moderate or severe RI, including for those with end-stage renal disease. While discussing the advantages related to their common mechanism of action, this article also describes differences among the DPP-4 inhibitors (eg, related to their pharmacokinetic properties and the available clinical data). In conclusion, while initial data for these new therapies are promising, further experience is needed to fully assess the risk-benefit balance and clinical positioning of these agents in RI populations.

Safety of dipeptidyl peptidase 4 inhibitors: a perspective review

Dipeptidyl peptidase 4 (DPP-4) inhibitors are a relatively new class of oral antihyperglycemic agent that enhance insulin secretion by reducing degradation of endogenous glucagon-like peptide 1. Currently, sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin have been approved by the US Food and Drug Administration or the European Medicines Agency for use in patients with type 2 diabetes. Their glycemic efficacy has been well documented; however, data regarding their long-term safety are as yet inconclusive. While preclinical studies have indicated a potential cardioprotective effect of DPP-4 inhibitors, current clinical data from cardiovascular safety trials suggest a neutral effect on cardiovascular outcomes. Moreover, postmarketing experience has given rise to concerns about specific adverse events, including pancreatitis and hypersensitivity reactions. This review summarizes available evidence regarding safety of DPP-4 inhibitors. Overall, DPP-4 inhibitors appear to be a safe option for patients with type 2 diabetes. However, close pharmacovigilance is necessary to address the uncertainty regarding pancreas-related adverse events, while their potential impact on cardiovascular outcomes will be further elucidated after completion of more long-term studies.

Clinical practice considerations and review of the literature for the Use of DPP-4 inhibitors in patients with type 2 diabetes and chronic kidney disease

OBJECTIVE

Many commonly prescribed agents for the treatment of type 2 diabetes (T2DM) have important restrictions on use in patients with renal impairment. Prescribing information and published data on dipeptidyl peptidase-4 (DPP-4) inhibitors indicate that these agents are suitable for use in this patient population. However, a recent database analysis indicated prevalent underrecognition of renal impairment and limited awareness of prescription considerations associated with DPP-4 inhibitor use in patients with renal impairment. Thus, this article reviews recent literature on the safety, efficacy, pharmacokinetics, and clinical use of DPP-4 inhibitors in patients with renal impairment and T2DM.

METHODS

PubMed searches were conducted for literature describing the use of DPP-4 inhibitors in patients with renal impairment.

RESULTS

Most DPP-4 inhibitors are characterized by significant renal clearance. As a result, pharmacokinetics are measurably affected by the presence of renal impairment; plasma exposure of DPP-4 inhibitors and their metabolites may increase by up to sevenfold in severe impairment/end-stage renal disease. The exception in this case is linagliptin, which is eliminated predominantly via the hepatobiliary system. Our search identified several studies that evaluated specific doses of DPP-4 inhibitors in patients with renal impairment and reported positive safety and efficacy results.

CONCLUSIONS

Overall, DPP-4 inhibitors are an effective means of controlling blood glucose in patients with T2DM and renal impairment. Considering the restrictions associated with many other antihyperglycemic agents when used in patients with renal impairment, DPP-4 inhibitors should be a considered as a treatment option in this patient population.

Randomized controlled clinical trial of a combination therapy of vildagliptin plus an α-glucosidase inhibitor for patients with type II diabetes mellitus

The aim of this study was to assess the efficacy of a combination therapy of vildagliptin plus an α-glucosidase inhibitor for patients with type II diabetes mellitus. Type II diabetic patients exhibiting poor glycemic control following α-glucosidase inhibitor treatment for at least two months were selected and randomly distributed into vildagliptin and placebo groups. The body weight, fasting blood glucose (FBG), postprandial glucose (PPG), glycated hemoglobin (HBA1c) and blood lipid levels and hepatorenal functions of the patients were determined before and 12 weeks after the trial. Following the trial, the FBG, PPG, HbA1c, cholesterol (CHOL) and triglyceride (TG) levels in the vildagliptin group were significantly decreased compared with the pretreatment levels (P<0.05), whereas only the PPG level in the placebo group decreased (P<0.05). The FBG, PPG and HbA1c levels in the vildagliptin group were markedly lower than those in the placebo group 12 weeks after the trial. A comparison of the body weights and hepatorenal functions before and after the trial or between groups did not show statistically significant differences. The combination therapy of vildagliptin plus an α-glucosidase inhibitor effectively reduced the FBG, PPG and HbA1c levels in patients without inducing weight gain or hepatorenal dysfunction. However, the therapy may have caused a reduction in the blood lipid levels.

The pharmacokinetic considerations and adverse effects of DPP-4 inhibitors [corrected]

INTRODUCTION

Dipeptidyl-peptidase-4 (DPP-4) inhibitors are a class of anti-hyperglycemic agents with proven efficacy in patients with type 2 diabetes mellitus (T2DM).

AREAS COVERED

This review considers the pharmacokinetic profile, adverse effects and drug interactions of DPP-4 inhibitors. DPP-4 inhibitors have certain differences in their structure, metabolism, route of elimination and selectivity for DPP-4 over structurally related enzymes, such as DPP-8/DPP-9. They have a low potential for drug interactions, with the exception of saxagliptin that is largely metabolized by cytochrome CYP3A4/A5. Reports of pancreatitis and pancreatic cancer have raised concerns regarding the safety of DPP-4 inhibitors and are under investigation. Post-marketing surveillance has revealed less common adverse effects, especially a number of skin- and immune-related adverse effects. These issues are covered in the present review.

EXPERT OPINION

DPP-4 inhibitors are useful and efficient drugs. DPP-4 inhibitors have similar mechanism of action and similar efficacy. However, DPP-4 inhibitors have certain differences in their pharmacokinetic properties that may be associated with different clinical effects and adverse event profiles. Although clinical trials indicated a favorable safety profile, post-marketing reports revealed certain safety aspects that need further investigation. Certainly, more research is needed to clarify if the differences among DPP-4 inhibitors could lead to a different clinical and safety profile.

Pharmacokinetic and toxicological considerations for the treatment of diabetes in patients with liver disease

INTRODUCTION

Patients with type 2 diabetes have an increased risk of chronic liver disease (CLD) such as non-alcoholic fatty liver disease and steatohepatitis and about one-third of cirrhotic patients have diabetes. However, the use of several antidiabetic agents may be a cause for concern in the case of hepatic impairment (HI).

AREAS COVERED

An extensive literature search was performed to analyze the influence of HI on the pharmacokinetics (PK) of glucose-lowering agents and the potential consequences for clinical practice as far as the efficacy/safety balance of their use in diabetic patients with CLD is concerned.

EXPERT OPINION

Almost no PK studies have been published regarding metformin, sulfonylureas, thiazolidinediones and α-glucosidase inhibitors in patients with HI. Only mild changes in PK of glinides, dipeptidyl peptidase-4 inhibitors and sodium glucose cotransporters type 2 inhibitors were observed in dedicated PK studies in patients with various degrees of HI, presumably without major clinical relevance although large clinical experience is lacking. Glucagon-like peptide-1 receptor agonists have a renal excretion rather than liver metabolism. Rare anecdotal case reports of hepatotoxicity have been described with various glucose-lowering agents contrasting with numerous reassuring data. Nevertheless, caution should be recommended, especially in patients with advanced cirrhosis, including with the use of metformin.