Efficacy and tolerability of vildagliptin vs. pioglitazone when added to metformin: a 24-week, randomized, double-blind study

Lobeglitazone: A Novel Thiazolidinedione for the Management of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and β-cell dysfunction. Among available oral antidiabetic agents, only the thiazolidinediones (TZDs) primarily target insulin resistance. TZDs improve insulin sensitivity by activating peroxisome proliferator-activated receptor γ. Rosiglitazone and pioglitazone have been used widely for T2DM treatment due to their potent glycemic efficacy and low risk of hypoglycemia. However, their use has decreased because of side effects and safety issues, such as cardiovascular concerns and bladder cancer. Lobeglitazone (Chong Kun Dang Pharmaceutical Corporation), a novel TZD, was developed to meet the demands for an effective and safe TZD. Lobeglitazone shows similar glycemic efficacy to pioglitazone, with a lower effective dose, and favorable safety results. It also showed pleiotropic effects in preclinical and clinical studies. In this article, we summarize the pharmacologic, pharmacokinetic, and clinical characteristics of lobeglitazone.

Effectiveness and Tolerability of Vildagliptin and the Single Pill Combination of Vildagliptin and Metformin in "Real-World" Management of Type 2 Diabetes Mellitus: The G-FORCE Study

INTRODUCTION

Randomized clinical trials showed that vildagliptin is well tolerated and leads to clinically meaningful decreases in glycated hemoglobin (HbA1c) and fasting plasma glucose (FPG) both in monotherapy and as add-on therapy in inadequately controlled type 2 diabetes mellitus (T2DM) patients. Nevertheless, there is an increased interest for real-life studies to confirm the clinical trial findings in the setting of a daily clinical practice. The aim of this study was to evaluate the effectiveness and tolerability of vildagliptin in a real-life clinical setting and to explore factors determining drug adherence and T2DM management.

METHODS

G-FORCE was a prospective, observational, open-label, multi-center study in which T2DM patients were prescribed de novo vildagliptin. Clinical effectiveness was determined by changes in HbA1c and FPG and by the proportion of patients reaching glycemic goal. Data were collected at baseline, after 105 ± 15 days and after 180 ± 15 days.

RESULTS

A total of 1230 patients were included in this analysis. Mean age was 63.9 ± 10.8 years, and mean HbA1c and FPG levels were 8.2 ± 1.3% and 171.0 ± 53.3 mg/dL, respectively. At 180 days of treatment, HbA1c and FPG levels decreased to 7.2 ± 1.0% and 141.1 ± 44.0 mg/dL, respectively, while the proportion of patients reaching HbA1c and FPG goals rose from 8.6 to 44.6% and from 14.2 to 42.8%, respectively.

CONCLUSION

In this real-world study, vildagliptin was an effective and safe treatment for T2DM patients already treated with metformin, while the single pill combination of vildagliptin and metformin provides a convenient alternative while ensuring comparable effectiveness and tolerability.

FUNDING

Novartis Pharma.

The Vildagliptin Experience - 25 Years Since the Initiation of the Novartis Glucagon-like Peptide-1 Based Therapy Programme and 10 Years Since the First Vildagliptin Registration

The discovery of the incretin hormone glucagon like peptide-1 (GLP-1), and its usefulness in the treatment of type 2 diabetes mellitus (T2DM) followed by the finding that dipeptidyl peptidase-4 (DPP-4) inhibition prevents GLP-1 inactivation, led to the discovery of DPP-728. In 1999, studies with DPP-728 established the first proof-of-concept that DPP-4 inhibition improves glycaemic control in patients with T2DM. Further efforts to improve the binding kinetics of DPP-728 resulted in the discovery of vildagliptin (LAF237). In the last 20 years, a plethora of studies conducted by Novartis in collaboration with external investigators has demonstrated the mechanism of action of vildagliptin and its efficacy as monotherapy and as an add-on therapy for patients with T2DM. The studies establish that vildagliptin is a selective DPP-4 inhibitor that blocks GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) inactivation, thereby prolonging their action, resulting in improved glycaemic control. This review aims to discuss the discovery and development of vildagliptin, with an emphasis on mechanism of action and clinical efficacy.

Metformin: clinical use in type 2 diabetes

Metformin is one of the most popular oral glucose-lowering medications, widely considered to be the optimal initial therapy for patients with type 2 diabetes mellitus. Interestingly, there still remains controversy regarding the drug's precise mechanism of action, which is thought to involve a reduction in hepatic glucose production. It is now recommended as first-line treatment in various guidelines, including that of the EASD and ADA. Its favoured status lies in its efficacy, low cost, weight neutrality and good safety profile. Other benefits have also been described, including improvements in certain lipids, inflammatory markers, and a reduction in cardiovascular events, apparently independent from the drug's glucose-lowering effect. Data have emerged questioning the previous reluctance to use this agent in those with mild to moderate chronic kidney disease. Regulations guiding its use in patients with stable, modest renal dysfunction have, as a result, become more lenient in recent years. With no long-term studies comparing it against newer glucose-lowering drugs, some of which have more robust evidence for cardioprotection, metformin's established role as 'foundation therapy' in type 2 diabetes may justifiably be challenged.

Targeting Peroxisome Proliferator-Activated Receptors Using Thiazolidinediones: Strategy for Design of Novel Antidiabetic Drugs

Thiazolidinediones are a class of well-established antidiabetic drugs, also named as glitazones. Thiazolidinedione structure has been an important structural domain of research, involving design and development of new drugs for the treatment of type 2 diabetes. Extensive research on the mechanism of action and the structural requirements has revealed that the intended antidiabetic activity in type 2 diabetes is due to their agonistic effect on peroxisome proliferator-activated receptor (PPAR) belonging to the nuclear receptor super family. Glitazones have specific affinity to PPARγ, one of the subtypes of PPARs. Certain compounds under development have dual PPARα/γ agonistic activity which might be beneficial in obesity and diabetic cardiomyopathy. Interesting array of hybrid compounds of thiazolidinedione PPARγ agonists exhibited therapeutic potential beyond antidiabetic activity. Pharmacology and chemistry of thiazolidinediones as PPARγ agonists and the potential of newer analogues as dual agonists of PPARs and other emerging targets for the therapy of type 2 diabetes are presented. This review highlights the possible modifications of the structural components in the general frame work of thiazolidinediones with respect to their binding efficacy, potency, and selectivity which would guide the future research in design of novel thiazolidinedione derivatives for the management of type 2 diabetes.

The role of various peroxisome proliferator-activated receptors and their ligands in clinical practice

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in several physiological processes including modulation of cellular differentiation, development, metabolism of carbohydrates, lipids, proteins, and tumorigenesis. The aim of this review is to examine how different PPAR ligands act, and discuss their use in clinical practice. PPAR ligands have a lot of effects and applications in clinical practice. Some PPAR ligands such as fibrates (PPAR-α ligands) are currently used for the treatment of dyslipidemia, while pioglitazone and rosiglitazone (PPAR-γ ligands) are anti-diabetic and insulin-sensitizing agents. Regarding new generation drugs, acting on both α/γ, β/δ, or α/δ receptors simultaneously, preliminary data on PPAR-α/γ dual agonists revealed a positive effect on lipid profile, blood pressure, atherosclerosis, inflammation, and anti-coagulant effects, while the overexpression of PPAR-β/δ seems to prevent obesity and to decrease lipid storage in cardiac cells. Finally, PPAR-α/δ dual agonist induces resolution of nonalcoholic steatohepatitis without fibrosis worsening.

Pattern of Onset and Risk Factors for Peripheral Oedema During Vildagliptin Use: Analysis from the Vildagliptin Prescription-Event Monitoring Study in England

INTRODUCTION

Clinical trials have identified peripheral oedema (PO) as an adverse event of vildagliptin (an oral anti-diabetic drug [OAD]). A post-marketing study (PMS) was conducted to advance the understanding of vildagliptin use and particular safety concerns identified within the risk-management plan. PMS objectives included comparing the hazards between vildagliptin monotherapy and combination therapy for selected a priori identified risks, including PO.

AIM

This study was a per-protocol supplementary analysis to investigate the pattern of onset and effect of vildagliptin combination therapy on PO risk.

METHODS

The PMS used an observational cohort design. OAD exposure, selected risk factors and outcome data were collected from general practitioners in England regarding vildagliptin users for the 6-month period after starting treatment. Data analysis comprised univariate case/non-case analysis, time-to-onset analysis and Cox proportional hazard models to estimate hazard ratios (HR) of PO adjusting for selected patients' baseline characteristics.

RESULTS

The study cohort included 4828 patients (median age 63 years; interquartile range [IQR] 54-71), 2692 of whom were male (55.8 %). The crude cumulative hazard of PO was 19.09 cases (95 % confidence interval [CI] 13.54-26.10) per 1000 person-years; 50 % of cases occurred during the first 34 days of treatment. A significantly faster time to PO onset was observed in patients prescribed concomitant sulfonylureas versus other treatment combinations (log rank test [LRT] p = 0.0365); in patients with a prior history of PO (LRT p < 0.001), arrhythmia (LRT p = 0.0003) or hypertension (LRT p = 0.0125); and in patients aged ≥60 years (LRT p = 0.0047). Similarly, the case/non-case univariate analysis indicated that patients with PO were older; had a higher prevalence of a history of either arrhythmia, hypertension or PO; and frequently used a sulfonylurea in combination. In the hazard function analysis, only sex and prior PO history had a profound effect on risk of PO after starting vildagliptin. Furthermore, effect modification was observed between sex and prior PO history; in male patients of average age (62 years), the HR was 12.84 (95 % CI 4.96-33.23); in females, it was 1.44 (95 % CI 0.32-6.40).

CONCLUSIONS

In this planned supplementary analysis, the findings suggest that PO occurred most frequently within 1 month after starting treatment with vildagliptin, and previous PO history and male sex in elderly patients were important predictors of this risk. The observation that concomitant use of a sulfonylurea may also increase PO risk early after starting treatment should be taken into consideration if prescribing OADs in combination with vildagliptin.

Hypoglycaemia when adding sulphonylurea to metformin: a systematic review and network meta-analysis

AIMS

The risk of hypoglycaemia may differ among sulphonylureas (SUs), but evidence from head-to-head comparisons is sparse. Performing a network meta-analysis to use indirect evidence from randomized controlled trials (RCTs), we compared the relative risk of hypoglycaemia with newer generation SUs when added to metformin.

METHODS

A systematic review identified RCTs lasting 12-52 weeks and evaluating SUs added to inadequate metformin monotherapy (≥1000 mg/day) in type 2 diabetes. Adding RCTs investigating the active comparators from the identified SU trials, we established a coherent network. Hypoglycaemia of any severity was the primary end point.

RESULTS

Thirteen trials of SUs and 14 of oral non-SU antihyperglycaemic agents (16 260 patients) were included. All reported hypoglycaemia only as adverse events. Producing comparable reductions in HbA_1C of -0.66 to -0.84% (-7 to -9 mmol/mol), the risk of hypoglycaemia was lowest with gliclazide compared to glipizide (OR 0.22, CrI: 0.05 to 0.96), glimepiride (OR 0.40, CrI: 0.13 to 1.27), and glibenclamide (OR 0.21, CrI: 0.03 to 1.48). A major limitation is varying definitions of hypoglycaemia across studies.

CONCLUSIONS

When added to metformin, gliclazide was associated with the lowest risk of hypoglycaemia between the newer generation SUs. Clinicians should consider the risk of hypoglycaemia agent-specific when selecting an SU agent.

Differences in glycemic control across world regions: a post-hoc analysis in patients with type 2 diabetes mellitus on dual antidiabetes drug therapy

Objective:

This post-hoc analysis of the EDGE (Effectiveness of Diabetes control with vildaGliptin and vildagliptin/mEtformin) study assessed inter-regional differences in baseline characteristics and response to treatment intensification with dual oral antidiabetes drugs (OADs) in patients with type 2 diabetes mellitus (T2DM).

Methods:

Patients with T2DM inadequately controlled with first-line monotherapy were assigned to receive a dipeptidyl peptidase-4 (DPP-4) inhibitor, vildagliptin, or comparator OADs as add-on dual therapy. The primary effectiveness end point (PEP) was achieving glycated hemoglobin (HbA1c) reduction >0.3% without hypoglycemia, peripheral edema, discontinuation owing to gastrointestinal events or weight gain ⩾5% at 12 months. The secondary effectiveness end point (SEP) was achieving HbA1c of <7% without hypoglycemia or weight gain ⩾3% at 12 months.

Results:

Baseline characteristics of patients (N=43 791), including mean HbA1c (8.2%), varied across regions. Baseline age (62.3 years) and T2DM duration (6.3 years) were greater in patients from Europe than those from India and the Middle East (age: 51.8 and 52.1 years; T2DM duration: 4.3 and 4.2 years, respectively). The probability of achieving PEP with dual therapy was higher in India (odds ratio (OR): 1.5), Latin America (OR: 1.2) and Middle East (OR: 2.0) than in Europe (OR: 0.8) and East Asia (OR: 0.3). Achievement of SEP in patients receiving dual therapy was greater in Latin America (OR: 1.7) and Middle East (OR: 1.7). Vildagliptin add-on therapy allowed more patients to achieve SEP across regions. Women aged ⩾45 years less often attained glycemic target (HbA1c<7%) without significant weight gain ⩾5% compared with women aged <45 years (OR: 0.876, 95% confidence interval: 0.774, 0.992; P=0.037).

Conclusions:

Baseline HbA1c and T2DM duration differed considerably across all regions. Treatment intensification with second OAD, particularly with a DPP-4 inhibitor vildagliptin, resulted in good treatment response without tolerability issues despite delayed intensification of failing monotherapy across regions.

Comparison of Vildagliptin and Pioglitazone in Korean Patients with Type 2 Diabetes Inadequately Controlled with Metformin

BACKGROUND

We compared the efficacies of vildagliptin (50 mg twice daily) relative to pioglitazone (15 mg once daily) as an add-on treatment to metformin for reducing glycosylated hemoglobin (HbA1c) levels in Korean patients with type 2 diabetes.

METHODS

The present study was a multicenter, randomized, active-controlled investigation comparing the effects of vildagliptin and pioglitazone in Korean patients receiving a stable dose of metformin but exhibiting inadequate glycemic control. Each patient underwent a 16-week treatment period with either vildagliptin or pioglitazone as an add-on treatment to metformin.

RESULTS

The mean changes in HbA1c levels from baseline were -0.94% in the vildagliptin group and -0.6% in the pioglitazone group and the difference between the treatments was below the non-inferiority margin of 0.3%. The mean changes in postprandial plasma glucose (PPG) levels were -60.2 mg/dL in the vildagliptin group and -38.2 mg/dL in the pioglitazone group and these values significantly differed (P=0.040). There were significant decreases in the levels of total, low density lipoprotein, high density lipoprotein (HDL), and non-HDL cholesterol in the vildagliptin group but increases in the pioglitazone group. The mean change in body weight was -0.07 kg in the vildagliptin group and 0.69 kg in the pioglitazone group, which were also significantly different (P=0.002).

CONCLUSION

As an add-on to metformin, the efficacy of vildagliptin for the improvement of glycemic control is not inferior to that of pioglitazone in Korean patients with type 2 diabetes. In addition, add-on treatment with vildagliptin had beneficial effects on PPG levels, lipid profiles, and body weight compared to pioglitazone.

Clinical trial simulation methods for estimating the impact of DPP-4 inhibitors on cardiovascular disease

Introduction

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic agents for the treatment of type 2 diabetes mellitus, which lower blood glucose without causing severe hypoglycemia. However, the first cardiovascular (CV) safety trials have only recently reported their results, and our understanding of these therapies remains incomplete. Using clinical trial simulations, we estimated the effectiveness of DPP-4 inhibitors in preventing major adverse cardiovascular events (MACE) in a population like that enrolled in the SAVOR-TIMI (the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus – Thrombolysis in Myocardial Infarction) 53 trial.

Methods

We used the Archimedes Model to simulate a clinical trial of individuals (N=11,000) with diagnosed type 2 diabetes and elevated CV risk, based on established disease or multiple risk factors. The DPP-4 class was modeled with a meta-analysis of HbA_1c and weight change, pooling results from published trials of alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin. The study treatments were added-on to standard care, and outcomes were tracked for 20 years.

Results

The DPP-4 class was associated with an HbA_1c drop of 0.66% (0.71%, 0.62%) and a weight drop of 0.14 (−0.07, 0.36) kg. These biomarker improvements produced a relative risk (RR) for MACE at 5 years of 0.977 (0.968, 0.986). The number needed to treat to prevent one occurrence of MACE at 5 years was 327 (233, 550) in the elevated CV risk population.

Conclusion

Consistent with recent trial publications, our analysis indicates that DPP-4 inhibitors do not increase the risk of MACE relative to the standard of care. This study provides insights about the long-term benefits of DPP-4 inhibitors and supports the interpretation of the published CV safety trial results.

Dipeptidyl Peptidase 4: A New Link between Diabetes Mellitus and Atherosclerosis?

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent noncommunicable diseases in the past years. It is undoubtedly associated with atherosclerosis and increased risk for cardiovascular diseases. Incretins, which are intestinal peptides secreted during digestion, are able to increase insulin secretion and its impaired function and/or secretion is involved in the pathophysiology of T2DM. Dipeptidyl peptidase 4 (DPP4) is an ubiquitous enzyme that regulates incretins and consequently is related to the pathophysiology of T2DM. DPP4 is mainly secreted by endothelial cells and acts as a regulatory protease for cytokines, chemokines, and neuropeptides involved in inflammation, immunity, and vascular function. In T2DM, the activity of DPP4 seems to be increased and there are a growing number of in vitro and in vivo studies suggesting that this enzyme could be a new link between T2DM and atherosclerosis. Gliptins are a new class of pharmaceutical agents that acts by inhibiting DPP4. Thus, it is expected that gliptin represents a new pharmacological approach not only for reducing glycemic levels in T2DM, but also for the prevention and treatment of atherosclerotic cardiovascular disease in diabetic subjects. We aimed to review the evidences that reinforce the associations between DPP4, atherosclerosis, and T2DM.

The Place of Dipeptidyl Peptidase-4 Inhibitors in Type 2 Diabetes Therapeutics: A "Me Too" or "the Special One" Antidiabetic Class?

Incretin-based therapies, the most recent therapeutic options for type 2 diabetes mellitus (T2DM) management, can modify various elements of the disease, including hypersecretion of glucagon, abnormal gastric emptying, postprandial hyperglycaemia, and, possibly, pancreatic β cell dysfunction. Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) increase glucagon-like peptide-1 (GLP-1) availability and correct the "incretin defect" seen in T2DM patients. Clinical studies have shown good glycaemic control with minimal risk of hypoglycaemia or any other adverse effects, despite the reports of pancreatitis, whose association remains to be proved. Recent studies have been focusing on the putative ability of DPP-4 inhibitors to preserve pancreas function, in particular due to the inhibition of apoptotic pathways and stimulation of β cell proliferation. In addition, other cytoprotective effects on other organs/tissues that are involved in serious T2DM complications, including the heart, kidney, and retina, have been increasingly reported. This review outlines the therapeutic potential of DPP-4 inhibitors for the treatment of T2DM, focusing on their main features, clinical applications, and risks, and discusses the major challenges for the future, in particular the possibility of becoming the preferred therapy for T2DM due to their ability to modify the natural history of the disease and ameliorate nephropathy, retinopathy, and cardiovascular complications.

Comparative analysis of therapeutic efficiency and costs (experience in Bulgaria) of oral antidiabetic therapies based on glitazones and gliptins

Type 2 diabetes mellitus is a serious, chronic, progressive and widespread disease. Metformin is the most commonly prescribed initial therapy, but combination with other antidiabetic agents usually becomes necessary due to the progression of the disease. Pioglitazone is recommended as a second-line therapy because of its strong antihyperglycemic effect and its ability to reduce insulin resistance. Treatment with pioglitazone is associated with a significantly lower risk of cardiovascular complications and hypoglycemia, while simultaneously improving the lipid profile and the symptomatic and histological changes in the liver. Gliptins (sitagliptin and vildagliptin) are a new class of oral antidiabetic drugs which reduce glycated hemoglobin by a different mechanism. Although the efficacy of sitagliptin and vildagliptin is close to that of pioglitazone, the lack of long-term safety data and the higher price question their predominant use. The objective of this review is to highlight the advantages of mono- and combination therapy with pioglitazone in comparison with gliptins and to underline the inconsistencies in the medicinal and reimbursement policy in Bulgaria.

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.

Observational and clinical trial findings on the comparative effectiveness of diabetes drugs showed agreement

OBJECTIVES

This study compares an observational study of diabetes treatment effectiveness to randomized controlled trials to assess their convergent validity.

STUDY DESIGN AND SETTING

Multivariate models were developed using observational data to describe change in hemoglobin A1c (HbA1c; % unit) and weight (kilograms) after addition of a second-line oral diabetes drug to metformin monotherapy. Randomized trials of these scenarios were systematically identified. The models were used to simulate each trial, and simulated and actual results were compared by linear regression and meta-analysis.

RESULTS

Thirty-two randomized trials of second-line diabetes oral therapy were identified. For all outcomes and drugs studied, simulation and actual results correlated (P < 0.001). There were no statistically significant differences between meta-analyzed randomized and simulated results for effect on HbA1c. For effect on weight, results were qualitatively comparable, but for sulfonylureas, the simulated weight gain was nominally greater than seen in the randomized controlled trials.

CONCLUSION

An observational study of diabetes drug effectiveness showed convergent validity with randomized data. This supports cautious use of the observational research to draw conclusions about drug effectiveness in populations not studied in clinical trials. This approach may be useful in other situations where observational and randomized data need integration.

Achieving glycemic control in elderly patients with type 2 diabetes: a critical comparison of current options

The prevalence of type 2 diabetes mellitus (T2DM) is increasing in the elderly. Because of the unique characteristics of elderly people with T2DM, therapeutic strategy and focus should be tailored to suit this population. This article reviews the guidelines and studies related to older people with T2DM worldwide. A few important themes are generalized: 1) the functional and cognitive status is critical for older people with T2DM considering their life expectancy compared to younger counterparts; 2) both severe hypoglycemia and persistent hyperglycemia are deleterious to older adults with T2DM, and both conditions should be avoided when determining therapeutic goals; 3) recently developed guidelines emphasize the avoidance of hypoglycemic episodes in older people, even in the absence of symptoms. In addition, we raise the concern of glycemic variability, and discuss the rationale for the selection of current options in managing this patient population.

Efficacy of vildagliptin versus sulfonylureas as add-on therapy to metformin: comparison of results from randomised controlled and observational studies

AIMS/HYPOTHESIS

Randomised control trials (RCTs) do not always reflect real-life outcomes for glucose-lowering drugs. In this work we compared RCT and real-life data on the efficacy of the dipeptidyl peptidase-IV (DPP-4) inhibitor vildagliptin or sulfonylureas when added to metformin.

METHODS

Data were pooled from five RCTs examining vildagliptin (n = 2,788) and sulfonylureas (glimepiride [n = 1,259] or gliclazide [n = 433]), added to metformin. For real-life conditions, data were extracted from an observational study examining vildagliptin (n = 7,002) or sulfonylureas (n = 3,702), added to metformin monotherapy. Linear regression analyses were performed between the baseline HbA1c and the change in HbA1c (Δ HbA1c) after 24 weeks.

RESULTS

Baseline HbA1c correlated to Δ HbA1c (r (2) = 0.36, slope = -0.54 [95% CI -0.55, -0.53; p < 0.0001]) for both treatments. With sulfonylureas, the slope of the correlation was steeper in the observational study than in RCTs (interaction coefficient = -0.327, p < 0.001), whereas for vildagliptin, the slope was virtually identical in the observational study and the RCTs (interaction coefficient = 0.024, p = 0.175). For any given baseline HbA1c, Δ HbA1c with sulfonylureas was smaller in real life than in RCTs, whereas Δ HbA1c with vildagliptin was the same.

CONCLUSIONS/INTERPRETATIONS

When comparing RCT to real-life data, the decrease in HbA1c from baseline with sulfonylurea treatment is smaller in real life than in RCTs, whereas the reduction with vildagliptin is essentially the same, suggesting that the full power of treatment is retained in real life for vildagliptin but not for sulfonylureas, possibly due to fear of hypoglycaemia.

Comparative effectiveness of dipeptidylpeptidase-4 inhibitors in type 2 diabetes: a systematic review and mixed treatment comparison

OBJECTIVE

To compare the safety and efficacy of the dipeptidylpeptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes and inadequate glycemic control.

DESIGN

Systematic review of randomized controlled trials (RCTs), health economic evaluation studies, systematic reviews, and meta-analyses, followed by primary Bayesian mixed treatment comparison meta-analyses (MTCs), and secondary frequentist direct-comparison meta-analyses using a random-effects model. Outcomes were reported as weighted mean change from baseline, or odds ratio (OR) with 95% credible interval.

DATA SOURCES

MEDLINE, MEDLINE In-Process, EMBASE, and BIOSIS via Dialog ProQuest; Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews via EBSCO; four diabetes and two technical congress abstracts; and health technology assessment organization websites.

ELIGIBILITY CRITERIA

Patients with type 2 diabetes and inadequate glycemic control receiving any pharmacological anti-diabetic treatment.

DATA EXTRACTION AND ANALYSIS

Title/abstracts were reviewed for eligibility, followed by full-text review of publications remaining after first pass. A three-person team filtered articles and an independent reviewer checked a random selection (10%) of filtered articles. Data extraction and quality assessment of studies were also independently reviewed. Five DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin) were compared via meta-analysis (where data were available) as monotherapy, dual therapy (plus metformin, sulfonylurea, pioglitazone, or insulin), and triple therapy (plus metformin/sulfonylurea).

RESULTS

The review identified 6,601 articles; 163 met inclusion criteria and 85 publications from 83 RCTs contained sufficient or appropriate data for analysis. MTCs demonstrated no differences between DPP-4 inhibitors in mean change from baseline in glycosylated hemoglobin (HbA1c) or body weight, or the proportions of patients achieving HbA1c <7% or experiencing a hypoglycemic event, apart from in patients on alogliptin plus metformin, who achieved HbA1c <7% more frequently than those treated with saxagliptin plus metformin [OR 6.41 (95% CI 3.15-11.98) versus 2.17 (95% CI 1.56-2.95)].

CONCLUSIONS

This systematic review and MTC showed similar efficacy and safety for DPP-4 inhibitors as treatment for type 2 diabetes, either as monotherapy or combination therapy.

A randomized controlled clinical trial of vildagliptin plus metformin combination therapy in patients with type II diabetes mellitus

The aim of the present study was to assess the efficacy and safety of vildagliptin plus metformin combination therapy in patients with type II diabetes mellitus. Type II diabetic patients with poor glycemic control following at least three months of metformin treatment were selected and randomized into two groups. Vildagliptin or placebo was administered with metformin. Body weight, fasting blood glucose (FBG), postprandial glucose (PPG), glycated hemoglobin (HbA1c), blood lipid and hepatorenal function levels were analyzed in the patients prior to and 24-weeks after the trial. FBG, PPG and HbA1c levels of the patients in the vildagliptin group significantly decreased following the trial, whereas no statistically significant differences were observed in the various indicators of the placebo group prior to and following the trial. The FBG, PPG and HbA1c levels in the vildagliptin group were significantly lower compared with the placebo group 24-weeks after the trial. Comparisons of body weight, blood lipid and hepatorenal function between the groups prior to and following the trial exhibited no statistically significant differences. Therefore, vildagliptin plus metformin combination therapy effectively reduced FBG, PPG and HbA1c levels in patients with no risk of weight gain or hepatorenal dysfunction.

Effectiveness and tolerability of second-line therapy with vildagliptin vs. other oral agents in type 2 diabetes: a real-life worldwide observational study (EDGE)

AIM

Real-life studies are needed to confirm the clinical relevance of findings from randomised controlled trials (RCTs). This study aimed to assess the effectiveness and tolerability of vildagliptin add-on vs. other oral antihyperglycaemic drugs (OADs) added to OAD monotherapy in a real-life setting, and to explore the advantages and limitations of large-scale 'pragmatic' trials.

METHODS

EDGE was a prospective, 1-year, worldwide, real-life observational study in which 2957 physicians reported on the effects of second-line OADs in 45,868 patients with T2DM not reaching glycaemic targets with monotherapy. Physicians could add any OAD, and patients entered either vildagliptin or (pooled) comparator cohort. The primary effectiveness and tolerability end-point (PEP) evaluated proportions of patients decreasing HbA(1c) > 0.3%, without hypoglycaemia, weight gain, peripheral oedema or gastrointestinal side effects. The most clinically relevant secondary end-point (SEP 3) was attainment of end-point HbA(1c) < 7% without hypoglycaemia or ≥ 3% increase in body weight.

RESULTS

In this large group of T2DM patients, a second OAD was added at mean HbA(1c) of 8.2 ± 1.3%, with no baseline HbA(1c) difference between cohorts. Second-line OAD therapy attained the PEP in the majority of patients, with higher attainment in those prescribed a vildagliptin-based regimen. The adjusted odds ratio was 1.49 (95% CI: 1.42, 1.55; p < 0.001). In patients with baseline HbA(1c) ≥ 7%, SEP 3 was achieved by 35% of patients on a vildagliptin-based combination and by 23% of those receiving comparator combinations. The adjusted odds ratio was 1.96 (95% CI: 1.85, 2.07; p < 0.001). Safety events were reported infrequently and safety profiles of vildagliptin and other OADs were consistent with previous data.

CONCLUSION

EDGE demonstrates that in a 'real-life' setting, vildagliptin as second OAD can lower HbA(1c) to target without well-recognised OAD side effects, more frequently than comparator OADs. In addition, EDGE illustrates that conducting large-scale, prospective, real-life studies poses challenges but yields valuable clinical information complementary to RCTs.

Advances in pharmacologic therapies for type 2 diabetes

Type 2 diabetes (T2DM) is a multi-causal, heterogeneous and progressive cardiometabolic condition, with an increasing prevalence worldwide. T2DM is associated with multiple comorbidities that may impact patients' quality of life. Treatment is multifactorial, but pharmacologic treatment of hyperglycemia is still regarded as the mainstay of diabetes management. Current established therapies include metformin, sulfonylurea agents and insulin, the long-term use of which was associated with reduced micro- and macrovascular events in the United Kingdom Prospective Diabetes Study. Despite major recent advances in diabetes care, a large proportion of patients remain in poor glycemic control, necessitating the development of new therapeutic options. The recently published position statement of the American Diabetes Association and European Association for the Study of Diabetes for the management of hyperglycemia in T2DM has accommodated this wider range of therapy choices, as it is less prescriptive and advocates an individualized treatment approach, taking into account many relevant patient- and disease-related factors. This review summarizes the updates on various established agents as well as the recent developments with regard to incretin-based therapies, inhibitors of the renal tubular sodium-glucose-linked-transporter-2 and ultra-long acting basal insulin formulations.

A review of newer treatment approaches for type-2 diabetes: Focusing safety and efficacy of incretin based therapy

Diabetes resulting from both genetic and lifestyle factors causes high insulin deficiency or its resistance. As hyperglycemia and decreased insulin secretion and/or its sensitivity appear to be the primary defects associated with diabetes, available treatments focus on reducing those defects. A novel approach of treatment is to target the incretin mimetic hormones, which are secreted by intestinal cells in response to food intake, provoking glucose-dependent insulin secretion from the pancreas. Efficacy and safety studies of dipetidyl peptidase inhibitors (DPP-IV), sitagliptin, vildagliptin and linagliptin provide similar improvements in HbA1c levels when compared with metformin, sulfonylureas or glitazones without contributing to weight gain and hypoglycemia. Caution is required when choosing the gliptin in people with renal or hepatic impairment and with a risk of pancreatitis. The glucagon like peptide (GLP-1) analogues Exenatide and Liraglutide also have positive impact on glycemic control especially when used as a combination therapy. Another upcoming approach is using sodium-glucose co transporter two inhibitors in kidney, by exploring pathophysiology of renal glucose re absorption in the proximal tubule.

Profile of vildagliptin in type 2 diabetes: efficacy, safety, and patient acceptability

Vildagliptin is a selective and potent dipeptidyl peptidase-4 inhibitor that improves glycemic control by inhibiting the degradation of both endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide. This article is a comprehensive review of the safety and efficacy of vildagliptin in patients with type 2 diabetes. Clinical evidence has proven that it effectively decreases hemoglobin A_1c with a low risk of hypoglycemia and is weight neutral. The addition of vildagliptin to metformin improves glucose control and significantly reduces gastrointestinal adverse events, particularly in patients inadequately controlled with metformin monotherapy. Its long-term advantages include preservation of β-cell function, reduction in total cholesterol, decrease in fasting lipolysis in adipose tissue, and triglyceride storage in non-fat tissues. Vildagliptin is well tolerated with a low incidence of AEs, and it does not increase the risk of cardiovascular/cerebrovascular (CCV) events. It can be taken before or after meals, and has little drug interaction, thus it will be well accepted.

Effect of addition of either sitagliptin or pioglitazone in patients with uncontrolled type 2 diabetes mellitus on metformin: A randomized controlled trial

OBJECTIVE

To compare and study the dipeptidy1 peptidase-4 (DPP-4) inhibitors in combination with metformin against established combination therapies.

MATERIALS AND METHODS

This 16-week study was designed to compare sitagliptin versus pioglitazone as add-on therapy in patients of type 2 diabetes mellitus inadequately controlled with metformin alone. Fifty-two patients were randomized into two groups to receive either sitagliptin 100 mg (group 1) or pioglitazone 30 mg (group 2) in addition to metformin. The primary efficacy end point was change in HbA1c. Secondary end points included change in fasting plasma glucose (FPG), body weight and lipid profile. Treatment satisfaction was assessed using the Diabetes Treatment Satisfaction Questionnaire. Both the groups had a significant decrease in HbA1c.

RESULTS

There was no significant difference between mean reductions in FPG in both the groups. There was a significant decrease in the mean body weight and body mass index in group 1 in contrast to the significant increase in the same in group 2. Both the treatment groups reported a significant decrease in High-density lipoprotein (HDL-C) and Triglyceride.

CONCLUSION

Sitagliptin was well tolerated without any incidence of hypoglycemia. It was concluded that sitagliptin as an add-on to metformin is as effective and well tolerated as pioglitazone.

Predictive clinical parameters and glycemic efficacy of vildagliptin treatment in korean subjects with type 2 diabetes

BACKGROUND

The aims of this study are to investigate the glycemic efficacy and predictive parameters of vildagliptin therapy in Korean subjects with type 2 diabetes.

METHODS

In this retrospective study, we retrieved data for subjects who were on twice-daily 50 mg vildagliptin for at least 6 months, and classified the subjects into five treatment groups. In three of the groups, we added vildagliptin to their existing medication regimen; in the other two groups, we replaced one of their existing medications with vildagliptin. We then analyzed the changes in glucose parameters and clinical characteristics.

RESULTS

Ultimately, 327 subjects were analyzed in this study. Vildagliptin significantly improved hemoglobin A1c (HbA1c) levels over 6 months. The changes in HbA1c levels (ΔHbA1c) at month 6 were -2.24% (P=0.000), -0.77% (P=0.000), -0.80% (P=0.001), -0.61% (P=0.000), and -0.34% (P=0.025) for groups 1, 2, 3, 4, and 5, respectively, with significance. We also found significant decrements in fasting plasma glucose levels in groups 1, 2, 3, and 4 (P<0.05). Of the variables, initial HbA1c levels (P=0.032) and history of sulfonylurea use (P=0.026) were independently associated with responsiveness to vildagliptin treatment.

CONCLUSION

Vildagliptin was effective when it was used in subjects with poor glycemic control. It controlled fasting plasma glucose levels as well as sulfonylurea treatment in Korean type 2 diabetic subjects.

Efficacy of vildagliptin in combination with insulin in patients with type 2 diabetes and severe renal impairment

Background

The purpose of this study was to evaluate the efficacy of vildagliptin 50 mg once daily in patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m²) and longstanding type 2 diabetes not adequately controlled with insulin therapy, which is a difficult-to-treat population, with limited therapeutic options and a high susceptibility to hypoglycemia.

Methods

This was a post hoc subanalysis of data obtained during a previously described randomized, double-blind, parallel-group, 24-week study comparing the efficacy and safety of vildagliptin 50 mg once daily versus placebo in patients with type 2 diabetes and moderate or severe renal impairment. The present data derive from 178 patients with severe renal impairment (baseline estimated glomerular filtration rate approximately 21 mL/min/1.73 m², 100 randomized to vildagliptin, 78 randomized to placebo), all of whom were receiving insulin therapy (alone or in combination with an oral antidiabetic agent) for longstanding type 2 diabetes (mean approximately 19 years).

Results

With vildagliptin in combination with insulin, the adjusted mean change (AMΔ) in HbA_1c from baseline (7.7% ± 0.1%) was −0.9% ± 0.4% and the between-treatment difference (vildagliptin – placebo) was −0.6% ± 0.2% (P < 0.001). The percentage of patients achieving endpoint HbA_1c < 7.0% was significantly higher with vildagliptin than placebo (45.2% versus 22.8%, P = 0.008). When added to insulin, vildagliptin and placebo had comparable hypoglycemic profiles and did not cause weight gain. Both treatments were similarly well tolerated, with comparable incidences of adverse events, serious adverse events, and deaths.

Conclusion

When added to insulin therapy in patients with severe renal impairment and longstanding type 2 diabetes, vildagliptin 50 mg once daily was efficacious, eliciting HbA_1c reductions consistent with those previously reported for a patient population with much more recent onset of type 2 diabetes and normal renal function, and had a hypoglycemic profile comparable with placebo. Accordingly, vildagliptin is a suitable treatment option for patients with advanced type 2 diabetes and impaired renal function who require insulin therapy and present a serious therapeutic challenge in clinical practice.

Challenges in achieving optimal glycemic control in type 2 diabetes patients with declining renal function: The Southeast Asia perspective

It is well recognised that Asia is at the epicenter of the global type 2 diabetes epidemic. Driven by socioeconomic changes involving industrialization, urbanization and adoption of Western lifestyles, the unprecedented increases in the prevalence of diabetes are particularly evident in Southeast Asia. The impact of diabetes is immense, and despite evidence of the benefit of optimal glucose control in reducing the risk of disease progression and development of macrovascular and microvascular complications, many individuals in this region remain poorly controlled. Chronic kidney disease (CKD) is an increasingly common diabetes-associated complication in Asian patients. Furthermore, Southeast Asia has one of the highest rates of end-stage renal disease (ESRD) in the world. Consequently, CKD in diabetes is associated with considerable morbidity and cardiovascular-related mortality, highlighting the need to screen and assess patients early in the course of the disease. The management of type 2 diabetes patients with declining renal function represents a significant challenge. Many of the older antidiabetic agents, such as metformin and sulfonylureas, are limited in their utility in CKD as a result of contraindications or hypoglycemic episodes. In contrast, dipeptidyl-peptidase IV inhibitors have provided a welcome addition to the therapeutic armamentarium for achieving glycemic control in these special populations. With comparable efficacy to and more favorable pharmacokinetic and side-effect profiles than traditional therapies, agents in this drug class, such as linagliptin, offer a more tailored approach to disease control in type 2 diabetes patients with declining renal function.

Impact of insulin resistance, body mass index, disease duration, and duration of metformin use on the efficacy of vildagliptin

INTRODUCTION

The optimal stage for dipeptidyl peptidase-4 (DPP-4) inhibitor therapy in the course of type 2 diabetes mellitus (T2DM) is still under discussion, with often a perception that treatment with these agents may be less beneficial with increasing disease progression, due to loss of beta-cell function, and with increasing insulin resistance (IR), where beta-cell function is less prominent. This work, therefore, aimed to assess the impact of such factors on the efficacy of the DPP-4 inhibitor, vildagliptin, in add-on therapy to metformin.

METHODS

A pooled analysis of 24-week efficacy data of vildagliptin 50 mg twice daily (b.i.d.) (n = 2,478) from four add-on to metformin studies was performed. Analyses for changes in hemoglobin A(1c) (HbA(1c)) were stratified according to baseline IR stage (homeostasis model assessment [Homa IR] <5, ≥5), body mass index (BMI) (<27, ≥27 to <30, ≥30 kg/m(2)), T2DM duration (0 to <1, ≥1 to <5, ≥5 years), and duration of metformin use (0 to <1, ≥1 to <5, ≥5 years). Data from patients treated with sulfonylureas (SUs) (n = 2,010) in the pooled studies are provided as reference.

RESULTS

Patients in the vildagliptin and SU groups had mean age, HbA(1c), BMI, Homa IR, duration of T2DM and metformin use of 58 years, 7.7%, 32 kg/m(2), 4.3, 5.9 years and 3.0 years, respectively. Reductions from baseline in HbA(1c) with vildagliptin were very similar across Homa IR (mean 2.8 and 8.6), BMI (mean 24.9, 28.5, and 35.3 kg/m(2)), T2DM duration (mean 0.6, 2.9, and 9.7 years), and duration of metformin use (mean 0.6, 2.6, and 7.9 years) categories, showing significant drops in HbA(1c) of approximately -0.7% (baseline 7.7%). The results in patients receiving SUs were comparable to those seen in the vildagliptin group.

CONCLUSION

Vildagliptin add-on therapy to metformin was efficacious independent of IR stage and BMI, as well as disease duration and duration of prior metformin use, indicating that, contrary to a not uncommon perception, more obese patients and patients with long-standing T2DM can benefit from treatment with the DPP-4 inhibitor, vildagliptin.

Incretin-based therapies

Incretin-based therapies have established a foothold in the diabetes armamentarium through the introduction of oral dipeptidyl peptidase-4 inhibitors and the injectable class, the glucagon-like peptide-1 receptor agonists. In 2009, the American Diabetes Association and European Association for the Study of Diabetes authored a revised consensus algorithm for the initiation and adjustment of therapy in Type 2 diabetes (T2D). The revised algorithm accounts for the entry of incretin-based therapies into common clinical practice, especially where control of body weight and hypoglycemia are concerns. The gut-borne incretin hormones have powerful effects on glucose homeostasis, particularly in the postprandial period, when approximately two-thirds of the β-cell response to a given meal is due to the incretin effect. There is also evidence that the incretin effect is attenuated in patients with T2D, whereby the β-cell becomes less responsive to incretin signals. The foundation of incretin-based therapies is to target this previously unrecognized feature of diabetes pathophysiology, resulting in sustained improvements in glycemic control and improved body weight control. In addition, emerging evidence suggests that incretin-based therapies may have a positive impact on inflammation, cardiovascular and hepatic health, sleep, and the central nervous system. In the present article, we discuss the attributes of current and near-future incretin-based therapies.

Pharmacology of dipeptidyl peptidase-4 inhibitors: similarities and differences

The dipeptidyl peptidase (DPP)-4 inhibitors, which enhance glucose-dependent insulin secretion from pancreatic β cells by preventing DPP-4-mediated degradation of endogenously released incretin hormones, represent a new therapeutic approach to the management of type 2 diabetes mellitus. The 'first-in-class' DPP-4 inhibitor, sitagliptin, was approved in 2006; it was followed by vildagliptin (available in the EU and many other countries since 2007, although approval in the US is still pending), saxagliptin (in 2009), alogliptin (in 2010, presently only in Japan) and linagliptin, which was approved in the US in May 2011 and is undergoing regulatory review in Japan and the EU. As the number of DPP-4 inhibitors on the market increases, potential differences among the different members of the class become important when deciding which agent is best suited for an individual patient. The aim of this review is to provide a comprehensive and updated comparison of the pharmacodynamic and pharmacokinetic properties of DPP-4 inhibitors, and to pinpoint pharmacological differences of potential interest for their use in therapy. Despite their common mechanism of action, these agents show significant structural heterogeneity that could translate into different pharmacological properties. At the pharmacokinetic level, DPP-4 inhibitors have important differences, including half-life, systemic exposure, bioavailability, protein binding, metabolism, presence of active metabolites and excretion routes. These differences could be relevant, especially in patients with renal or hepatic impairment, and when considering combination therapy. At the pharmacodynamic level, the data available so far indicate a similar glucose-lowering efficacy of DPP-4 inhibitors, either as monotherapy or in combination with other hypoglycaemic drugs, a similar weight-neutral effect, and a comparable safety and tolerability profile. Data on nonglycaemic parameters are scant at present and do not allow a comparison among DPP-4 inhibitors. Several phase III trials of DPP-4 inhibitors are currently ongoing; these trials, along with post-marketing surveillance data, will hopefully increase our knowledge about the long-term efficacy and safety of DPP-4 inhibitor therapy, the effect on pancreatic cell function and peripheral glucose metabolism, and the effect on cardiovascular outcomes in patients with type 2 diabetes.

Consensus report: the current role of self-monitoring of blood glucose in non-insulin-treated type 2 diabetes

The Coalition for Clinical Research--Self-Monitoring of Blood Glucose Scientific Board convened a meeting in San Francisco, CA, July 20-21, 2011, to discuss the current practice of self-monitoring of blood glucose (SMBG) in non-insulin-treated (NIT) type 2 diabetes mellitus (T2DM). Twelve physician panel members from academia, practice, and government attended this meeting. These experts came from the United States, Brazil, Canada, France, Germany, Italy, and the United Kingdom. In addition, three consultants from Australia, Germany, and the United States contributed to the group's final report. This coalition was organized by Diabetes Technology Society. Self-monitoring of blood glucose was studied from eight perspectives related to patients with NIT T2DM: (1) epidemiological studies; (2) randomized controlled trials (RCT)s and meta-analyses; (3) targets, timing, and frequency of SMBG use; (4) incidence and role of SMBG in preventing hypoglycemia with single-drug regimens and combination regimens consisting of antihyperglycemic agents other than secretagogues and insulin; (5) comparison of SMBG with continuous glucose monitoring; (6) technological capabilities and limitations of SMBG; (7) barriers to appropriate use of SMBG; and (8) methods and end points for appropriate future clinical trials. The panel emphasized recent studies, which reflect the current approach for applying this intervention. Among the participants there was consensus that: SMBG is an established practice for patients with NIT T2DM, and to be most effective, it should be performed in a structured format where information obtained from this measurement is used to guide treatment; New, high-quality efficacy data from RCTs have demonstrated efficacy of SMBG in NIT T2DM in trials reported since 2008; Both patients and health care professionals require education on how to respond to the data for SMBG to be effective; and Additional well-defined studies are needed to assess the benefits and costs of SMBG with end points not limited to hemoglobin A1c.

Choosing a gliptin

The treatment of type 2 diabetes mellitus (T2DM) has included the use of metformin and sulfonylurea (SU) as first-line anti-diabetic therapies world over since years. This remains, despite the knowledge that the combination results in a progressive decline in [beta]-cell function and by 3 years up to 50% of diabetic patients can require an additional pharmacological agent to maintain the glycosylated hemoglobin (HbA1c) <7.0% (UKPDS). Gliptins represent a novel class of agents that improve beta cell health and suppress glucagon, resulting in improved post-prandial and fasting hyperglycemia. They function by augmenting the incretin system (GLP-1 and GIP) preventing their metabolism by dipeptidyl peptidase-4 (DPP-4). Not only are they efficacious but also safe (weight neutral) and do not cause significant hypoglycemia, making it a unique class of drugs. This review focuses on gliptins (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin) discussing pharmacokinetics, pharmacodynamics, efficacy, and safety.

Comparison of vildagliptin-metformin and glimepiride-metformin treatments in type 2 diabetic patients

BACKGROUND

The present study investigated the efficacy and safety of vildagliptin-metformin treatment compared to those of glimepiride-metformin treatment for type 2 diabetes.

METHODS

In a randomized, open-label, comparative study, 106 patients with type 2 diabetes were enrolled. The primary endpoint was a reduction in HbA1c from baseline and secondary endpoints included fasting plasma glucose (FPG) or 2-hour postprandial glucose (2h-PPG) reduction from baseline, as well as HbA1c responder rate and HbA1c reduction according to baseline HbA1c category.

RESULTS

Comparable HbA1c reduction was observed with a mean±standard deviation change from baseline to the 32-week endpoint of -0.94±1.15% in the vildagliptin group and -1.00±1.32% in the glimepiride group. A similar reduction in 2h-PPG (vildagliptin group 3.53±4.11 mmol/L vs. the glimepiride group 3.72±4.17 mmol/L) was demonstrated, and the decrements in FPG (vildagliptin group 1.54±2.41 mmol/L vs. glimepiride group 2.16±2.51 mmol/L) were not different between groups. The proportion of patients who achieved an HbA1c less than 7% at week 32 was 50.1% in the vildagliptin group and 56.0% in the glimepiride group. An average body weight gain of 2.53±1.21 kg in the glimepiride group was observed in contrast with the 0.23±0.69 kg weight gain noted in the vildagliptin group. A 10-fold lower incidence of hypoglycemia was demonstrated in the vildagliptin group, in addition to an absence of severe hypoglycemia.

CONCLUSION

Vildagliptin-metformin treatment provided blood glucose control efficacy comparable to that of glimepiride-metformin treatment and resulted in better adverse event profiles with lower risks of hypoglycemia and weight gain.

Vildagliptin: a review of its use in type 2 diabetes mellitus

Vildagliptin (Galvus®, Jalra®, Xiliarx®) is an orally administered dipeptidyl peptidase-4 (DPP-4) inhibitor. In patients with type 2 diabetes mellitus, vildagliptin 50 mg twice daily is indicated for use in combination with metformin or a thiazolidinedione, and vildagliptin 50 mg once daily is indicated for use in combination with a sulfonylurea. A fixed-dose combination of vildagliptin/metformin (Eucreas®, Icandra®, Zomarist®) is also available. This article reviews the clinical efficacy and tolerability of vildagliptin in patients with type 2 diabetes, as well as summarizing its pharmacological properties. The efficacy of monotherapy or combination therapy with oral vildagliptin in patients with type 2 diabetes has been examined in randomized, double-blind, multicentre trials. Monotherapy with vildagliptin 50 mg once or twice daily reduced glycosylated haemoglobin (HbA(1c)) from baseline to a significantly greater extent than placebo, according to the results of 12- to 52-week trials in patients with type 2 diabetes. In terms of the reduction from baseline in HbA(1c) seen in active comparator trials of 12-104 weeks' duration, the noninferiority of vildagliptin 50 mg twice daily was established versus acarbose or rosiglitazone, the noninferiority of vildagliptin 100 mg once daily (an off-label dosage) versus metformin was established in elderly patients and vildagliptin 50 mg twice daily was more effective than voglibose; however, the noninferiority of vildagliptin 50 mg twice daily versus metformin or gliclazide was not established in two other trials. Combination therapy with vildagliptin 50 mg twice daily plus metformin improved HbA(1c) to a significantly greater extent than monotherapy with metformin and/or vildagliptin alone in patients with type 2 diabetes whose disease was inadequately controlled by metformin monotherapy or who were treatment naive, according to the results of 12- or 24-week trials. In addition, vildagliptin 50 mg twice daily plus metformin demonstrated noninferiority to pioglitazone plus metformin, glimepiride plus metformin or gliclazide plus metformin in terms of the change from baseline in HbA(1c) after 24 or 52 weeks' therapy in patients with inadequately controlled type 2 diabetes. The addition of vildagliptin 50 mg twice daily to pioglitazone or vildagliptin 50 mg once daily to glimepiride improved HbA(1c) to a significantly greater extent than a thiazolidinedione or glimepiride alone in patients with type 2 diabetes whose disease was inadequately controlled, according to the results of 24-week trials. Oral vildagliptin 50 mg once or twice daily was generally well tolerated in patients with type 2 diabetes. In particular, vildagliptin was associated with a low risk of hypoglycaemia and was weight neutral. Increases in transaminase levels were sometimes observed with a vildagliptin dosage of 100 mg once daily in clinical trials, and liver function should be monitored in patients receiving vildagliptin. However, meta-analyses of clinical trial data suggested that vildagliptin 50 mg once or twice daily was not associated with an increased risk of hepatic adverse events, transaminase elevations ≥3 × the upper limit of normal, pancreatitis, cardiovascular or cerebrovascular events, infections or skin-related toxicity. In conclusion, vildagliptin is an important option for use in combination with metformin, a sulfonylurea or a thiazolidinedione in patients with type 2 diabetes who require combination therapy.

Second-line therapy in patients with type 2 diabetes inadequately controlled with metformin monotherapy: a systematic review and mixed-treatment comparison meta-analysis

BACKGROUND

Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the choice of second-line therapy once metformin is no longer effective. We conducted a systematic review and meta-analysis to assess the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

METHODS

MEDLINE, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to October 2009. Additional citations were obtained from grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected studies, extracted data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, quality of life, long-term diabetes-related complications, serious adverse drug events and mortality. Mixed-treatment comparison and pairwise meta-analyses were conducted to pool trial results, when appropriate.

RESULTS

We identified 49 active and non-active controlled randomized trials that compared 2 or more of the following classes of antihyperglycemic agents and weight-loss agents: sulfonylureas, meglitinides, thiazolidinediones (TZDs), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins, alpha-glucosidase inhibitors, sibutramine and orlistat. All classes of second-line antihyperglycemic therapies achieved clinically meaningful reductions in hemoglobin A1c (0.6% to 1.0%). No significant differences were found between classes. Insulins and insulin secretagogues were associated with significantly more events of overall hypoglycemia than the other agents, but severe hypoglycemia was rarely observed. An increase in body weight was observed with the majority of second-line therapies (1.8 to 3.0 kg), the exceptions being DPP-4 inhibitors, alpha-glucosidase inhibitors and GLP-1 analogues (0.6 to -1.8 kg). There were insufficient data available for diabetes complications, mortality or quality of life.

INTERPRETATION

DPP-4 inhibitors and GLP-1 analogues achieved improvements in glycemic control similar to those of other second-line therapies, although they may have modest benefits in terms of weight gain and overall hypoglycemia. Further long-term trials of adequate power are required to determine whether newer drug classes differ from older agents in terms of clinically meaningful outcomes.

Assessing the general safety and tolerability of vildagliptin: value of pooled analyses from a large safety database versus evaluation of individual studies

Aim:

Analyzing safety aspects of a drug from individual studies can lead to difficult-to-interpret results. The aim of this paper is therefore to assess the general safety and tolerability, including incidences of the most common adverse events (AEs), of vildagliptin based on a large pooled database of Phase II and III clinical trials.

Methods:

Safety data were pooled from 38 studies of ≥12 to ≥104 weeks’ duration. AE profiles of vildagliptin (50 mg bid; N = 6116) were evaluated relative to a pool of comparators (placebo and active comparators; N = 6210). Absolute incidence rates were calculated for all AEs, serious AEs (SAEs), discontinuations due to AEs, and deaths.

Results:

Overall AEs, SAEs, discontinuations due to AEs, and deaths were all reported with a similar frequency in patients receiving vildagliptin (69.1%, 8.9%, 5.7%, and 0.4%, respectively) and patients receiving comparators (69.0%, 9.0%, 6.4%, and 0.4%, respectively), whereas drug-related AEs were seen with a lower frequency in vildagliptin-treated patients (15.7% vs 21.7% with comparators). The incidences of the most commonly reported specific AEs were also similar between vildagliptin and comparators, except for increased incidences of hypoglycemia, tremor, and hyperhidrosis in the comparator group related to the use of sulfonylureas.

Conclusions:

The present pooled analysis shows that vildagliptin was overall well tolerated in clinical trials of up to >2 years in duration. The data further emphasize the value of a pooled analysis from a large safety database versus assessing safety and tolerability from individual studies.

Patient considerations and clinical utility of a fixed dose combination of saxagliptin/metformin in the treatment of type 2 diabetes

INTRODUCTION

Targeting glycated hemoglobin (HbA(1c)) levels below 7.0% is considered a primary goal of diabetes care, given its importance in obtaining a sustained reduction in microvascular, and possibly macrovascular complications.

AIM

The aim of this review was to evaluate the clinical utility of a fixed dose combination of saxagliptin/metformin in the treatment of type 2 diabetes.

EVIDENCE REVIEW

The combination of saxagliptin/metformin was well tolerated and produced sustained glycemic control for up to 76 weeks, with greater improvements in glycemic parameters compared with either drug alone. The saxagliptin/metformin combination also proved its non-inferiority compared with either sulfonylurea/metformin or sitagliptin/metformin combinations.

PLACE IN THERAPY

Clinical practice recommends lifestyle interventions together with starting metformin at the time that the type 2 diabetes mellitus is diagnosed. Once metformin fails to maintain glycemic control, the addition of DPP-4 inhibitors should be the logical choice because of their effects on HbA(1c) compared to the addition of a sulfonylurea or glitazone, and because of their positive effects on beta cell function and their neutral effects on body weight. Furthermore, DPP-4 inhibitors prevent the risk of hypoglycemia posed by sulfonylureas.

Comparative evaluation of incretin-based antidiabetic medications and alternative therapies to be added to metformin in the case of monotherapy failure

Aims/Introduction:  To compare clinical consequences of using inretin-based medications versus conventional antidiabetic agents as add-on to metformin in case of monotherapy failure in patients with type 2 diabetes.

MATERIALS AND METHODS

  The medical literature including recent abstracts from international diabetes conferences was searched for reports from clinical trials with incretin mimetics (GLP-1 receptor agonists), inhibitors of dipeptidyl peptidase-4 (DPP-4, incretin enhancers) and conventional antidiabtic drugs coadministered with metformin after monotherapy failure. A scoring system is suggested to compare the clinical utility of using incretin-based versus conventional antidiabetic agents in this situation.

RESULTS

  Incretin mimetics and DPP-4 inhibitors on top of metformin treatment help achieve glycaemic control comparable to other efficient antidiabetic drugs, both if separate or head-to-head trials were considered. Incretin-based antidiabetic drugs did not cause hypoglycaemia (different from sulfonylureas, meglitinides and insulin) and weight gain (different from sulfonylureas, meglitinides, thiazolidinediones, and insulin). DPP-4 inhibitors were weight neutral, incretin mimetics lead to weight loss. The clinical profile of incretin-based medications received the highest scores, followed by α-glucosidase inhibitors, with far lower scores assigned to insulin, glitazones, and sulfonyureas (in this order).

CONCLUSIONS

  Based on the results from clinical trials, incretin-based medications have been shown to be efficacious antidiabetic drugs with a favourable adverse event and tolerability profile. This leads to high scores using a novel system paying attention to multiple facets contributing to the selection of antidiabetic drugs for general recommendation and individual treatment choices.

Use of DPP-4 inhibitors in type 2 diabetes: focus on sitagliptin

Inhibition of dipeptidyl peptidase-4 (DPP-4) prevents the inactivation of glucagonlike peptide-1 (GLP-1). This increases circulating levels of active GLP-1, stimulates insulin secretion and inhibits glucagon secretion, which results in lowering of glucose levels and improvement of the glycemic control in patients with type 2 diabetes. This review summarizes experiences with DPP-4 inhibition in the treatment of type 2 diabetes, with a focus on sitagliptin. Sitagliptin has in several clinical studies been shown to improve metabolic control in type 2 diabetes, both when used as monotherapy and when used in combination with metformin, sulfonylurea, thiazolidinediones or insulin. The reduction in HbA(1c) is ≈ 0.6% to 1.0% from baseline levels of 7.5% to 8.7% over 6 to 12 months therapy. Sitagliptin has a favorable safety profile, is highly tolerable, and there is a minimal risk of hypoglycemia. Furthermore, sitagliptin is body weight neutral or induces a slight body weight reduction. Sitagliptin may be used in the early stages of type 2 diabetes in combination with metformin or other treatments in subjects with inadequate glycemic control on these treatments alone. Sitagliptin may also be used in monotherapy and, finally, sitagliptin may be used in combination with insulin in more advanced stages of the disease.

Effect of vildagliptin as add-on therapy to a low-dose metformin

AIM: To evaluate the efficacy and safety of the addition of vildagliptin to low-dose metformin and compare it to an uptitration of metformin in type 2 diabetes mellitus (T2DM) patients who have inadequate control with metformin monotherapy.

METHODS: Eligible patients were randomized to receive vildagliptin 100 mg qd or metformin (500 mg qd for 2 wk and then 500 mg bid) added to open label metformin 500 mg bid for the 24 wk. The primary endpoint was baseline to endpoint hemoglobin A_1c (HbA_1c) change.

RESULTS: The adjusted mean change from baseline in HbA_1c at the 24th wk was -0.51% in the vildagliptin/metformin group (mean baseline HbA_1c: 7.4%) and -0.37% in the metformin monotherapy group (mean baseline HbA_1c: 7.3%). The mean difference was -0.14% with 95% Confidence Interval (-0.24%, -0.05%). As non-inferiority (margin of 0.4%) was achieved, a test for superiority was performed. This test showed statistically significant superiority of the combination over monotherapy group (P = 0.002). Gastrointestinal (GI) adverse events were significantly more frequent in the metformin group than the combination group (21.0% vs 15.4%, P = 0.032).

CONCLUSION: In patients with T2DM inadequately controlled with metformin up to 1000 mg daily, the addition of vildagliptin 100 mg daily achieved larger HbA_1c reduction with fewer GI events than with increasing the metformin dose.

Dipeptidyl peptidase-4 inhibitors in the management of type 2 diabetes: safety, tolerability, and efficacy

Although glycemic control is an important and effective way to prevent and minimize the worsening of diabetes-related complications, type 2 diabetes is a progressive disease which often proves difficult to manage. Most affected patients will eventually require therapy with multiple medications in order to reach appropriate glycemic targets. The dipeptidyl peptidase-4 (DPP-4) inhibitors constitute a relatively new class of oral medications for the treatment of type 2 diabetes, which has become widely incorporated into clinical practice. This review summarizes the available data on the efficacy, safety, and tolerability of these medications.

Incretin-based therapies: new treatments for type 2 diabetes in the new millennium

The advent of 'incretin-based therapies' - GLP-1 agonists and dipeptidyl-peptidase-4 inhibitors - which result in improvements in glycemic control comparable to those with existing oral hypoglycemic agents, and potentially improve cardiovascular and pancreatic beta-cell function, represents a major therapeutic advance in the management of type 2 diabetes. Gastrointestinal adverse effects occur commonly with GLP-1 agonists, and rarely with DPP-4 inhibitors, but are dose-dependent and usually transient. The low risk of hypoglycemia, and beneficial or neutral effects on body weight, render GLP-1 agonists and DPP-4 inhibitors suitable alternatives to insulin secretagogues and insulin in overweight and elderly patients. Incretin-based therapies also improve quality of life in patients with type 2 diabetes, and may be cost-effective in the long term.

Incretin-based therapies for type 2 diabetes mellitus

Incretin-based drugs, such as glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors, are now routinely used to treat type 2 diabetes mellitus. These agents regulate glucose metabolism through multiple mechanisms, their use is associated with low rates of hypoglycemia, and they either do not affect body weight (dipeptidyl peptidase 4 inhibitors), or promote weight loss (glucagon-like peptide-1 receptor agonists). The success of exenatide and sitagliptin, the first therapies in their respective drug classes to be based on incretins, has fostered the development of multiple new agents that are currently in late stages of clinical development or awaiting approval. This Review highlights our current understanding of the mechanisms of action of incretin-based drugs, with an emphasis on the emerging clinical profile of new agents.

Vildagliptin: a new oral treatment for type 2 diabetes mellitus

Vildagliptin is a new oral antidiabetic agent that enhances pancreatic islet cell responsiveness to glucose. An extensive clinical program involving approximately 22,000 patients and 7000 patient-years of exposure to vildagliptin has shown that the agent is well tolerated and efficacious in improving glycemic control in patients with type 2 diabetes mellitus (T2DM). Monotherapy trials have shown that significant HbA1c lowering is accompanied by body weight-neutral and lipid-neutral effects, low risk of edema, and low risk of hypoglycemia. These characteristics make vildagliptin a favorable partner for combination therapy. Studies of vildagliptin as an add-on to metformin have shown significant improvements in glycemic control (comparable to that of thiazolidinedione add-on), with the combination being well tolerated and associated with low risks for hypoglycemia and adverse effects on weight or lipid levels. Good tolerability and clinically relevant improvements in glycemic control have also been observed with vildagliptin as an add-on treatment to sulfonylurea, thiazolidinedione, or insulin treatment or in initial combination treatment with pioglitazone. Improved beta-cell function and glycemic control have been shown with vildagliptin in subjects with impaired glucose tolerance and in T2DM patients with mild hyperglycemia, with some evidence in the latter suggesting the potential for modifying disease course.

Islet G protein-coupled receptors as potential targets for treatment of type 2 diabetes

Islet dysfunction - characterized by a combination of defective insulin secretion, inappropriately high glucagon secretion and reduced beta-cell mass - has a central role in the pathophysiology of type 2 diabetes. Several G protein-coupled receptors (GPCRs) expressed in islet beta-cells are known to be involved in the regulation of islet function, and therefore are potential therapeutic targets. This is evident from the recent success of glucagon-like peptide 1 (GLP1) mimetics and dipeptidyl peptidase 4 (DPP4) inhibitors, which promote activation of the GLP1 receptor to stimulate insulin secretion and inhibit glucagon secretion, and also have the potential to increase beta-cell mass. Other islet beta-cell GPCRs that are involved in the regulation of islet function include the glucose-dependent insulinotropic peptide (GIP) receptor, lipid GPCRs, pleiotropic peptide GPCRs and islet biogenic amine GPCRs. This Review summarizes islet GPCR expression, signalling and function, and highlights their potential as targets for the treatment of type 2 diabetes.

Incretin-based therapies in type 2 diabetes mellitus

CONTEXT

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide are incretins secreted from enteroendocrine cells postprandially in part to regulate glucose homeostasis. Dysregulation of these hormones is evident in type 2 diabetes mellitus (T2DM). Two new drugs, exenatide (GLP-1 mimetic) and sitagliptin [dipeptidyl peptidase (DPP) 4 inhibitor], have been approved by regulatory agencies for treating T2DM. Liraglutide (GLP-1 mimetic) and vildagliptin (DPP 4 inhibitor) are expected to arrive on the market soon.

EVIDENCE ACQUISITION

The background of incretin-based therapy and selected clinical trials of these four drugs are reviewed. A MEDLINE search was conducted for published articles using the key words incretin, glucose-dependent insulinotropic polypeptide, GLP-1, exendin-4, exenatide, DPP 4, liraglutide, sitagliptin, and vildagliptin.

EVIDENCE SYNTHESIS

Exenatide and liraglutide are injection based. Three-year follow-up data on exenatide showed a sustained weight loss and glycosylated hemoglobin (HbA(1c)) reduction of 1%. Nausea and vomiting are common. Results from phase 3 studies are pending on liraglutide. Sitagliptin and vildagliptin are orally active. In 24-wk studies, sitagliptin reduces HbA(1c) by 0.6-0.8% as monotherapy, 1.8% as initial combination therapy with metformin, and 0.7% as add-on therapy to metformin. Vildagliptin monotherapy lowered HbA(1c) by 1.0-1.4% after 24 wk. Their major side effects are urinary tract and nasopharyngeal infections and headaches. Exenatide and liraglutide cause weight loss, whereas sitagliptin and vildagliptin do not.

CONCLUSIONS

The availability of GLP-1 mimetics and DPP 4 inhibitors has increased our armamentarium for treating T2DM. Unresolved issues such as the effects of GLP-1 mimetics and DPP 4 inhibitors on beta-cell mass, the mechanism by which GLP-1 mimetics lowers glucagon levels, and exactly how DPP 4 inhibitors lead to a decline in plasma glucose levels without an increase in insulin secretion, need further research.

Combination treatment in the management of type 2 diabetes: focus on vildagliptin and metformin as a single tablet

Vildagliptin is a potent and selective inhibitor of dipeptidyl peptidase-IV (DPP-4), orally active, that improves glycemic control in patients with type 2 diabetes (T2DM) primarily by enhancing pancreatic (alpha and beta) islet function. Thus vildagliptin has been shown both to improve insulin secretion and to suppress the inappropriate glucagon secretion seen in patients with T2DM. Vildagliptin reduces HbA(1c) when given as monotherapy, without weight gain and with minimal hypoglycemia, or in combination with the most commonly prescribed classes of oral hypoglycemic drugs: metformin, a sulfonylurea, a thiazolidinedione, or insulin. Metformin, with a different mode of action not addressing beta-cell dysfunction, has been used for about 50 years and still represents the universal first line therapy of all guidelines. However, given the multiple pathophysiological abnormalities in T2DM and the progressive nature of the disease, intensification of therapy with combinations is typically required over time. Recent guidelines imply that patients will require pharmacologic combinations much earlier to attain and sustain the increasingly stringent glycemic targets, with careful drug selection to avoid unwanted adverse events, especially hypoglycemia. The combination of metformin and vildagliptin offers advantages when compared to currently used combinations with additive efficacy and complimentary mechanisms of action, since it does not increase the risk of hypoglycemia and does not promote weight gain. Therefore, by specifically combining these agents in a single tablet, there is considerable potential to achieve better blood glucose control and to improve compliance to therapy.