Safety and efficacy of linagliptin as add-on therapy to metformin in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled study

Dipeptidyl peptidase-4 inhibitors and cardiovascular outcomes: meta-analysis of randomized clinical trials with 55,141 participants

AIMS

The association between glucose lowering in diabetes mellitus and major cardiovascular (CV) outcomes is weak; indeed, some oral hypoglycemic agents are associated with increased CV events. Dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) are a new class of oral hypoglycemic agent that may have beneficial CV effects. We undertook a systematic review and meta-analysis to appraise the CV safety and efficacy of DPP-4 inhibitors.

METHODS

Comprehensive search for prospective trials involving DPP-4 inhibitors. Trials included reported at least one of the outcomes examined, recruited minimum 100 patients and minimum follow-up 24 weeks. The risk ratio (RR) was calculated using the Mantel-Haenszel random-effects model for mortality and major cardiovascular (CV) outcomes.

RESULTS

Fifty trials enrolling 55,141 participants were included. Mean follow-up 45.3 weeks. DPP-4 inhibitors compared with all comparators (placebo and active) showed no difference in all-cause mortality (n = 50,982, RR = 1.01, 95% CI 0.91-1.13, P = 0.83), CV mortality (n = 48,151, RR = 0.97, 95% CI 0.85-1.11, P = 0.70), acute coronary syndrome (ACS) (n = 53,034 RR = 0.97, 95% CI 0.87-1.08, P = 0.59), or stroke (n = 42,737, RR = 0.98, 95% CI 0.81-1.18, P = 0.80), and a statistically significant increase in heart failure outcomes (n = 39,953, RR = 1.16, 95% CI 1.01-1.33, P = 0.04).

DISCUSSION

Treatment with DPP-4 inhibitors compared with placebo shows no increase in risk with regards to all-cause mortality, CV mortality, ACS, or stroke, but a statistically significant trend toward increased risk of HF outcomes.

CONCLUSION

These findings suggest no cardiovascular harm (or benefit) with DPP-4 inhibitors; further large-scale CV outcome studies will resolve the issue of excess HF risk.

Efficacy and safety of linagliptin co-administered with low-dose metformin once daily versus high-dose metformin twice daily in treatment-naïve patients with type 2 diabetes: a double-blind randomized trial

Introduction

The aim of this study was to investigate the efficacy and safety of linagliptin + low-dose (LD) metformin once daily versus high-dose (HD) metformin twice daily in treatment-naïve patients with type 2 diabetes.

Methods

Patients (n = 689) were randomized (1:1) to double-blind treatment with linagliptin 5 mg + LD metformin (1000 mg) or HD metformin (2000 mg) for 14 weeks. Metformin was initiated at 500 mg/day and up-titrated within 2 weeks; the dose then remained unchanged. The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline to Week 14 in patients who tolerated a daily metformin dose of ≥1000 mg after 2 weeks.

Results

At Week 14, HbA1c changed from a mean baseline of 8.0% (64 mmol/mol) by −0.99% (−11 mmol/mol) for linagliptin + LD metformin, and −0.98% (−11 mmol/mol) for HD metformin [treatment difference −0.01% (95% confidence interval −0.13, 0.12) (0 mmol/mol), P = 0.8924]. The proportion of patients who achieved HbA1c <7.0% (53 mmol/mol) without occurrence of moderate or severe gastrointestinal (GI) events (including abdominal pain, nausea, vomiting, diarrhea, and decreased appetite) was the same in both groups (51.3% for both). Although the occurrence of moderate or severe GI events was similar, the linagliptin + LD metformin group had fewer mild GI events (18.5% versus 24.3%). The incidence of hypoglycemia was low in both groups.

Conclusion

Linagliptin + LD metformin combination showed similar efficacy and safety to HD metformin. This combination may be an alternative treatment option in patients who may have difficulty tolerating metformin doses >1000 mg/day.

Funding

Boehringer Ingelheim.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0195-3) contains supplementary material, which is available to authorized users.

Combination of empagliflozin and linagliptin as second-line therapy in subjects with type 2 diabetes inadequately controlled on metformin

OBJECTIVE

To evaluate the efficacy and safety of combinations of empagliflozin/linagliptin as second-line therapy in subjects with type 2 diabetes inadequately controlled on metformin.

RESEARCH DESIGN AND METHODS

Subjects were randomized to a combination of empagliflozin 25 mg/linagliptin 5 mg (n = 137), empagliflozin 10 mg/linagliptin 5 mg (n = 136), empagliflozin 25 mg (n = 141), empagliflozin 10 mg (n = 140), or linagliptin 5 mg (n = 132) as add-on to metformin for 52 weeks. The primary end point was change from baseline in HbA1c at week 24.

RESULTS

At week 24, reductions in HbA1c (mean baseline 7.90-8.02% [62.8-64.1 mmol/mol]) with empagliflozin/linagliptin were superior to those with empagliflozin or linagliptin alone as add-on to metformin; adjusted mean (SE) changes from baseline were -1.19% (0.06) (-13.1 mmol/mol [0.7]) with empagliflozin 25 mg/linagliptin 5 mg, -1.08% (0.06) (-11.8 mmol/mol [0.7]) with empagliflozin 10 mg/linagliptin 5 mg, -0.62% (0.06) (-6.8 mmol/mol [0.7]) with empagliflozin 25 mg, -0.66% (0.06) (-7.2 mmol/mol [0.7]) with empagliflozin 10 mg, and -0.70% (0.06) (-7.6 mmol/mol [0.7]) with linagliptin 5 mg (P < 0.001 for all comparisons). In these groups, respectively, 61.8, 57.8, 32.6, 28.0, and 36.1% of subjects with baseline HbA1c ≥7% (≥53 mmol/mol) had HbA1c <7% (<53 mmol/mol) at week 24. Efficacy was maintained at week 52. The proportion of subjects with adverse events (AEs) over 52 weeks was similar across treatment arms (68.6-73.0%), with no hypoglycemic AEs requiring assistance.

CONCLUSIONS

Combinations of empagliflozin/linagliptin as second-line therapy for 52 weeks significantly reduced HbA1c compared with the individual components and were well tolerated.

Regardless of the degree of glycaemic control, linagliptin has lower hypoglycaemia risk than all doses of glimepiride, at all time points, over the course of a 2-year trial

AIM

To evaluate the risk of documented hypoglycaemia with glimepiride versus linagliptin.

METHODS

This was an exploratory analysis of data from a 2-year, randomized, double-blind study of the dipeptidyl peptidase-4 inhibitor linagliptin 5 mg once daily (n = 764) versus the sulphonylurea glimepiride 1-4 mg once daily (n = 755) in patients with type 2 diabetes uncontrolled by metformin. Patients randomized to glimepiride started on 1 mg and after 4 weeks were allowed to be individually uptitrated stepwise to glimepiride 4 mg if a fasting plasma glucose concentration ≤6.1 mmol/l was not achieved. Investigator-reported hypoglycaemia was evaluated by dose, over time, and by the degree of glycated haemoglobin (HbA1c) reduction.

RESULTS

The percentages of patients with at least one hypoglycaemic event at the individual maximum glimepiride dose were: 1 mg, 45.0%; 2 mg, 50.8%; 3 mg, 36.1%; and 4 mg, 27.7%. The incidence of hypoglycaemia was higher with glimepiride than with linagliptin (36.1 vs. 7.5%; p < 0.0001); after performing sensitivity analyses by excluding events during dose escalation (weeks 0-16), this difference remained significant (weeks 16-104: 25.8 vs. 5.9%; p < 0.0001). Notably, the incidence of hypoglycaemia was higher with glimepiride than with linagliptin in each quartile of HbA1c change from baseline (all p < 0.0001); the incidence of hypoglycaemic episodes was not increased with greater reductions in HbA1c in either group. In all 4-week intervals across the 2-year study, the incidence of hypoglycaemia was lower with linagliptin than with glimepiride.

CONCLUSION

Linagliptin was associated with a lower risk of hypoglycaemia than glimepiride at all dose levels and time intervals, and regardless of change in HbA1c level.

Linagliptin improves glycemic control after 1 year as add-on therapy to basal insulin in Asian patients with type 2 diabetes mellitus

OBJECTIVE

To evaluate the efficacy and long-term safety of linagliptin added to basal insulin in Asian patients with type 2 diabetes mellitus (T2DM) inadequately controlled by basal insulin with/without oral agents.

RESEARCH DESIGN AND METHODS

This was a post hoc analysis of Asian patients from a global ≥52 week study in which patients on basal insulin were randomized (1:1) to double-blind treatment with linagliptin 5 mg once daily or placebo (NCT00954447). Basal insulin dose remained stable for 24 weeks, after which adjustments could be made according to the investigator's discretion to improve glycemic control. The primary endpoint was the mean change in glycated hemoglobin (HbA1c) from baseline to 24 weeks.

RESULTS

Data were available for 154 Asian patients (80 linagliptin, 74 placebo). Baseline HbA1c (standard deviation [SD]) was 8.6 (0.9)% (70 [10] mmol/mol). The placebo-corrected mean change (standard error [SE]) in HbA1c from baseline was -0.9 (0.1)% (-10 [1] mmol/mol) (95% confidence interval [CI]: -1.2, -0.7; p<0.0001) at Week 24 and -0.9 (0.1)% (-10 [1] mmol/mol) (95% CI: -1.1, -0.6; p<0.0001) at Week 52. The frequency of adverse events (linagliptin 81.3%, placebo 91.9%) and hypoglycemia (Week 24: linagliptin 25.0%, placebo 25.7%; treatment end: linagliptin 28.8%, placebo 35.1%) was similar between groups. By Week 52, changes (SE) in mean body weight were similar in both groups (linagliptin -0.67 [0.26] kg, placebo -0.38 [0.25] kg).

CONCLUSIONS

This study was limited by the post hoc nature of the analysis and the small number of patients in the subgroup. However, the results suggest that linagliptin significantly improves glycemic control in Asian patients with T2DM inadequately controlled by basal insulin, without increasing the risk for hypoglycemia or weight gain. ClinicalTrials identifier: NCT00954447.

Pharmacologic treatment of type 2 diabetes: oral medications

OBJECTIVE

To review the oral and injectable pharmacologic treatment options for type 2 diabetes.

DATA SOURCES

A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included.

DATA SYNTHESIS

In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 9 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or those with a pending new drug application were highlighted.

CONCLUSION

There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Combination of linagliptin and metformin for the treatment of patients with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a progressive condition requiring long-term treatment. Most patients with T2DM are unable to maintain normoglycemia using metformin alone; thus, combination therapy is a pivotal part of disease management. Addition of the dipeptidyl peptidase-4 inhibitor linagliptin, with its proven efficacy, low propensity for hypoglycemia, and weight neutrality, has been shown to improve glycemic control for patients who are not well controlled with metformin. As patients often have other comorbidities requiring pharmacotherapy, an increase in pill number, different prescribing frequencies, and timing of medications may adversely impact patients’ adherence. Studies have shown that treatment nonadherence contributes to increased morbidity, mortality, and healthcare cost. In the United States, the single-pill combination (SPC) of linagliptin/metformin is available in three strengths approved for twice-daily administration: 2.5/500 mg, 2.5/850 mg, and 2.5/1000 mg. The SPC has the potential to reduce pill burden and simplify patients’ treatment regimens, thereby promoting improved adherence and efficacy.

Meta-analysis of studies examining medication adherence, persistence, and discontinuation of oral antihyperglycemic agents in type 2 diabetes

OBJECTIVE

To estimate overall rates of adherence, persistence, and discontinuation for patients with type 2 diabetes mellitus (T2DM) prescribed oral antihyperglycemic agents (OAHAs) by combining results of published studies.

RESEARCH DESIGN AND METHODS

A systematic literature review was conducted to identify articles published in English over the last 10 years evaluating the use of OAHAs for the treatment of T2DM. Databases searched included PubMed/MEDLINE, EMBASE, and the Cochrane Library. Seventy studies reporting adherence, persistence or discontinuation were identified by two independent reviewers and 40 reported relevant endpoints for the analysis. Outcomes included: (1) mean adherence defined as the average medication possession ratio (MPR); (2) proportion of adherent patients (MPR ≥ 80%); (3) discontinuation; and (4) persistence. Adherence and persistence were reported in observational studies only. Discontinuation was examined separately in randomized controlled trials (RCTs) and observational studies. Meta-analyses were conducted using both fixed and random effects models. When meta-analysis was not appropriate for a given outcome, descriptive statistics were provided.

RESULTS

The pooled mean MPR (95% confidence interval [CI]) was 75.3% (68.8%-81.7%; n = 13) and the proportion of adherent patients (95% CI) was 67.9% (59.6%-76.3%; n = 12). The discontinuation rate (95% CI) in RCTs was 31.8% (17.0%-46.7%; n = 7). Persistence and discontinuation were not assessed via meta-analysis for observational studies due to the limited number of available studies and differences in outcome definitions. In these studies, persistence estimates ranged from 41.0% to 81.1%, with a mean (95% CI) of 56.2% (46.1%-66.3%; n = 6), while discontinuation estimates ranged from 9.9% to 60.1%, with a mean (95% CI) of 31.4% (17.6%-45.3%; n = 6).

LIMITATIONS

Limitations include (1) the use of MPR as a proxy for adherence, (2) limited number of studies available, and (3) observed heterogeneity.

CONCLUSION

The results of the analysis demonstrate that medication adherence, persistence, and discontinuation rates are suboptimal in patients with T2DM prescribed OAHAs.

Incretin-based therapies

Incretin-based therapies are steadily gaining clinical popularity, with many more products in the developmental pipeline. Current treatment recommendations incorporate GLP-1 RAs and DPP-4 inhibitors as important agents for consideration in the treatment of T2DM owing to their low hypoglycemia risk, ability to address postprandial hyperglycemia (DPP-4 inhibitors and short-acting GLP-1 RAs), and potential for weight reduction (GLP-1 RAs). These properties may likewise prove advantageous in older adults in whom hypoglycemia is particularly undesirable, although older adults may be more prone to the nausea and vomiting associated with GLP-1 RA therapy. Other safety issues for incretin-based therapies, such as pancreatitis, C-cell hyperplasia, and renal failure, should be considered when choosing an appropriate patient to receive such therapies. Ongoing CV outcome studies will further inform the health care community regarding the CV safety of incretin-based therapies. The availability of both short-acting and long-acting GLP-1 RAs currently allows practitioners to consider individualized blood glucose trends and therapeutic needs when choosing an optimal agent.

Efficacy and safety of linagliptin as monotherapy or add-on treatment in Asian patients with suboptimal glycemic control: a pooled analysis

AIMS

To evaluate the efficacy and safety of the dipeptidyl peptidase (DPP)-4 inhibitor linagliptin in Asian patients with type 2 diabetes mellitus (T2DM), a rapidly increasing population.

METHODS

Data were pooled for Asian patients receiving linagliptin orally once daily, as monotherapy or added to existing oral antidiabetes therapies, in multinational randomized placebo-controlled clinical trials. Efficacy data were taken from four pivotal trials with 24-week durations to allow for robust efficacy assessment. Safety data were pooled from a wider group of 10 trials with varying durations to capture the largest possible incidence of adverse events (AEs). The primary efficacy endpoint was change from baseline to week 24 in HbA1c. AEs were analyzed descriptively.

RESULTS

Mean baseline HbA1c (±SD) in this population was 8.2 ± 0.9%. Placebo-corrected mean change in HbA1c after 24 weeks was -0.79% (95% confidence interval [CI]: -0.92 to -0.67; p < 0.0001). Placebo-corrected mean change in fasting plasma glucose was -17.8 ± 2.4 mg/dL (95% CI: -22.6, -13.0; p < 0.0001). In a small subgroup, mean post-prandial glucose was reduced by a placebo-corrected -56.9 ± 14.0 mg/dL (95% CI: -85.2, -28.5). AEs occurred in 58.0% of linagliptin patients (serious AEs in 2.4%) and 58.2% of placebo patients (serious AEs in 3.0%).

CONCLUSIONS

This study was limited by the post hoc nature of the analysis, and because the pooling did not differentiate between geographically distant Asian regions. Nonetheless, this analysis provides evidence that linagliptin was efficacious and well tolerated as monotherapy or added to other oral antidiabetes therapies in Asian patients with T2DM.

Linagliptin improved glycaemic control without weight gain or hypoglycaemia in patients with type 2 diabetes inadequately controlled by a combination of metformin and pioglitazone: a 24-week randomized, double-blind study

AIMS

To investigate the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with Type 2 diabetes mellitus inadequately controlled by a combination of metformin and pioglitazone.

METHODS

This was a multi-centre, phase 3, randomized, double-blind, placebo-controlled study comparing linagliptin 5 mg once daily (n = 183) and placebo (n = 89) as add-on to metformin and pioglitazone. The primary endpoint was the change from baseline in glycated haemoglobin (HbA1c ) after 24 weeks.

RESULTS

The placebo-corrected adjusted mean (se) change in HbA1c from baseline to 24 weeks was -6 (1) mmol/mol [-0.57 (0.13)%] (P < 0.0001). In patients with baseline HbA1c ≥ 53 mmol/mol (7.0%), 32.4% of patients in the linagliptin group and 13.8% in the placebo group achieved HbA1c < 53 mmol/mol (7.0%) (odds ratio 2.94; P = 0.0033). The placebo-corrected adjusted mean (se) change from baseline in fasting plasma glucose at week 24 was -0.57 (0.26) mmol/l [-10.4 (4.7) mg/dl] (P = 0.0280). The incidence of serious adverse events was 2.2% with linagliptin and 3.4% with placebo. Investigator-defined hypoglycaemia occurred in 5.5% of the linagliptin group and 5.6% of the placebo group. No meaningful changes in mean body weight were noted for either group.

CONCLUSIONS

Linagliptin as add-on therapy to metformin and pioglitazone produced significant and clinically meaningful improvements in glycaemic control, without an additional risk of hypoglycaemia or weight gain (Clinical Trials Registry No: NCT 00996658).

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.

Safety and efficacy of the dipeptidyl peptidase-4 inhibitor linagliptin in elderly patients with type 2 diabetes: a comprehensive analysis of data from 1331 individuals aged ≥ 65 years

AIMS

To investigate individual patient data from a comprehensive trials programme to evaluate the safety and efficacy of the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin across a range of glucose-lowering regimens in a large elderly population with type 2 diabetes mellitus (T2DM).

METHODS

Data were pooled from individuals aged ≥ 65 years, who participated in seven phase III, placebo-controlled clinical trials of linagliptin (24-52 weeks). Safety was assessed by incidence and severity of adverse events (AEs) with a focus on hypoglycaemia. The primary efficacy endpoint was change in glycated haemoglobin (HbA1c).

RESULTS

In total, 841 subjects received linagliptin 5 mg once a day and 490 received placebo. At baseline, the population had a mean ± s.d. age of 71.0 ± 4.6 years and a mean HbA1c concentration of 8.0 ± 0.8%; 63.5% of subjects received ≥ 2 antidiabetes drugs. Overall AEs and drug-related AEs were experienced by similar proportions of patients (linagliptin 71.3, placebo 73.3; linagliptin 18.1, placebo 19.8%, respectively). The incidence of investigator-reported hypoglycaemia was 21.4% with linagliptin and 25.7% with placebo. Severe hypoglycaemic events were rare and there were fewer in the linagliptin group (1.0 vs. 1.8%). At week 24, the placebo-corrected adjusted mean ± s.e. reduction in HbA1c with linagliptin was -0.62 ± 0.06% (95% CI: -0.73, -0.51).

CONCLUSIONS

Data from this large cohort show that linagliptin is a well-tolerated and efficacious therapy for elderly patients with T2DM. Treatment with linagliptin may support individualized treatment goals, while effectively managing the risk of hypoglycaemia or drug-related side effects.

Linagliptin for the treatment of type 2 diabetes mellitus: a drug safety evaluation

INTRODUCTION

Established treatments for type 2 diabetes mellitus (T2DM) have side effects that limit their use in specific populations. New therapies with improved safety profiles are needed, especially because of the chronic and progressive nature of T2DM.

AREAS COVERED

This review describes the overall safety and tolerability of linagliptin--a dipeptidyl peptidase-4 inhibitor that improves glycemic control without increasing risk for hypoglycemia and without weight gain. Specifically, the safety of linagliptin is evaluated in difficult-to-treat patients with T2DM, in relation to risk of cardiovascular (CV) events and acute pancreatitis, and in comparison with other antihyperglycemic drugs.

EXPERT OPINION

Linagliptin is generally well tolerated in a broad range of patient populations. It can be used in patients with renal impairment without dose titration and may be a rational alternative treatment in this vulnerable population. Ongoing long-term trials are fully evaluating the CV and renal safety profile of linagliptin.

Efficacy and safety of linagliptin in subjects with long-standing type 2 diabetes mellitus (>10 years): evidence from pooled data of randomized, double-blind, placebo-controlled, phase III trials

PURPOSE

Long duration of type 2 diabetes mellitus (T2DM) is associated with progressive β-cell loss and may pose a challenge to maintenance of good glycemic control. This study aimed to assess the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in an understudied population of patients with long-standing T2DM.

METHODS

Data from 202 individuals with T2DM for >10 years were pooled from 2 randomized, placebo-controlled, Phase III trials. Participants received either linagliptin 5 mg once daily (n = 122) or placebo (n = 80) for 24 weeks as an add-on to their current glucose-lowering therapy.

FINDINGS

Long-standing T2DM was associated with older age (mean [SD], 69.1 [10.0] years) and a high prevalence of diabetes-related complications (78% with diabetic kidney disease and 83% with macrovascular disease). The mean baseline glycosylated hemoglobin (HbA1c) level was 8.22% (1.08%), and mean baseline fasting plasma glucose level was 161.8 (49.2) mg/dL. Linagliptin significantly improved glycemic control after 24 weeks, with a placebo-adjusted mean change in HbA1c from baseline of -0.66% (95% CI, -0.95 to -0.38; P < 0.0001). This change was accompanied by a significant reduction in fasting plasma glucose, with a placebo-adjusted mean change from baseline of -15.5 mg/dL (95% CI, -29.6 to -1.3; P = 0.0323) at week 24. Overall, linagliptin was well tolerated, with drug-related adverse events in 21.3% and 16.3% of the linagliptin and placebo groups, respectively. Investigator-reported hypoglycemia occurred more often with linagliptin (25.4%) compared with placebo (12.5%). However, no severe hypoglycemic events were reported with linagliptin. Moreover, in patients not receiving concomitant sulfonylureas, the incidence of hypoglycemia with linagliptin (12.5%) was similar to that with placebo (12.2%). Patients' mean weight remained unchanged in both groups.

IMPLICATIONS

This pooled analysis found that linagliptin was well tolerated and significantly improved hyperglycemia in a clinically challenging population of patients with long-standing T2DM (>10 years). Although T2DM is commonly associated with diminished β-cell function, the extent of glucose lowering was similar to that in linagliptin trials, which largely included patients in earlier stages of the disease. Thus, this observation supports the hypothesis that regulation of glucagon release from pancreatic α cells may be of particular relevance for improving hyperglycemia in patients with long-term T2DM (NCT01194830 and NCT01084005).

Evidence-based practice use of incretin-based therapy in the natural history of diabetes

The incretin class of anti-hyperglycemic agents, including glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-inhibitors, is an important addition to the therapeutic armamentarium for the management of appropriate patients with type 2 diabetes mellitus as an adjunct to diet and exercise and/or with the agents metformin, sulfonylureas, thiazolidinediones, or any combination thereof. More recently, US Food and Drug Administration (FDA)-approved indications for incretins were expanded to include use with basal insulin. This review article takes an evidence-based practice approach in discussing the importance of aggressive treatment for diabetes, the principles of incretin physiology and pathophysiology, use of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, and patient types and contexts where incretin therapy has been found beneficial, from metabolic syndrome to overt diabetes.

Influence of TCF7L2 gene variants on the therapeutic response to the dipeptidylpeptidase-4 inhibitor linagliptin

AIMS/HYPOTHESIS

Individuals carrying variants of the transcription factor 7-like 2 gene (TCF7L2) are at increased risk for type 2 diabetes. These metabolic genetic risk factors have been linked to diminished pancreatic islet-cell responsiveness to incretins, thus pharmacological interventions aimed at amplifying endogenous incretin biology may be affected. However, clinical evidence from randomised controlled trials so far is lacking. We investigated the influence of TCF7L2 risk alleles on the response to treatment with the dipeptidylpeptidase-4 (DPP-4) inhibitor linagliptin from four 24 week, phase III, placebo-controlled trials.

METHODS

Pharmacogenomic samples and clinical data were available from 961 patients with type 2 diabetes. Whole-blood DNA samples were genotyped for TCF7L2 single-nucleotide polymorphisms in conjunction with assessments of 24 week changes in HbA1c.

RESULTS

Linagliptin lowered HbA1c meaningfully in all three genotypes of rs7903146 (non-risk variant carriers CC [n = 356]: -0.82% [-9.0 mmol/mol], p < 0.0001; heterozygous CT [n = 264]: -0.77% [-8.4 mmol/mol], p < 0.0001; homozygous risk variant carriers TT [n = 73]: -0.57% [-6.2 mmol/mol], p < 0.0006). No significant treatment differences were seen between CC and CT patients, although HbA1c response was reduced in TT compared with CC patients (~0.26% [~2.8 mmol/mol], p = 0.0182).

CONCLUSIONS/INTERPRETATION

Linagliptin significantly improved hyperglycaemia in patients with type 2 diabetes both with and without the TCF7L2 gene diabetes risk alleles. However, differences in treatment response were observed, indicating that diabetes susceptibility genes may be an important contributor to the inter-individual variability of treatment response.

Pharmacokinetics, safety, and efficacy of DPP-4 inhibitors and GLP-1 receptor agonists in patients with type 2 diabetes mellitus and renal or hepatic impairment. A systematic review of the literature

Renal or hepatic impairment, often encountered in patients with type 2 diabetes, influences the pharmacokinetics and bioavailability of antihyperglycemic agents. An emerging concern is whether pharmacotherapy with incretin-based agents, the most recent drug classes to be introduced for type 2 diabetes, can be safely used in patients with renal insufficiency or hepatic damage. This literature review examines the results of studies on these novel drug classes, with a view to provide the practitioner with a balanced, evidence-based position when considering incretin-based therapies in patients with type 2 diabetes and impaired kidney or liver function. All currently available dipeptidyl peptidase-4 (DPP-4) inhibitors appear to be appropriate pharmacotherapeutic choices in patients with declining renal function, with linagliptin affording the added advantage of not requiring dose adjustment or periodic monitoring of drug-related kidney function. In contrast, caution is warranted with the use of glucagon-like peptide-1 (GLP-1) receptor agonists in patients with moderate or severe renal impairment. The slightly wider evidence base for liraglutide than for exenatide or lixisenatide is not sufficient to support its use in severe renal impairment. What little evidence there is for incretin-based therapies in hepatic impairment has come from a few past hoc analysis of clinical trials, with most precautions and warnings reflecting the paucity of knowledge about incretin efficacy or safety in this condition.

Safety and Tolerability of Linagliptin in Patients With Type 2 Diabetes: A Comprehensive Pooled Analysis of 22 Placebo-controlled Studies

PURPOSE

Dipeptidyl peptidase (DPP)-4 inhibitors are an increasingly used antihyperglycemic therapy for patients with type 2 diabetes mellitus (T2DM). Linagliptin, an orally administered DPP-4 inhibitor, has demonstrated favorable efficacy/safety in clinical trials. The aim of this post hoc pooled analysis was to expand current knowledge of the safety of linagliptin.

METHODS

Safety data for once-daily linagliptin 5 mg (1 study of linagliptin 2.5 mg twice daily) were analyzed from 22 randomized, double-blind, Phase I-III, placebo-controlled clinical trials of ≤102 weeks' duration. Assessments of pooled data included incidence of patient-reported adverse events (AEs).

FINDINGS

Data from 7400 patients (linagliptin, 4810; placebo, 2590) were pooled. Most patients (58.4%) had T2DM diagnosis for >5 years; approximately 75% were receiving ≥1 type of background therapy in addition to linagliptin/placebo. Overall exposure to the study drug was 2412.8 years for linagliptin and 1481.4 years for placebo (mean [SD], 183 [120] days and 209 [150] days, respectively). Overall frequencies of AEs were similar for linagliptin- and placebo-treated patients (57.3% and 61.8%, respectively). The incidence of neoplastic AEs was low (0.6% and 0.9%, respectively); there were no reports of pancreatic neoplasia. Pancreatitis was observed in 2 linagliptin-treated patients (<0.1%) and 1 placebo-treated patient (<0.1%). The occurrence of cardiac disorder AEs was similar in linagliptin- and placebo-treated patients (3.2% [n = 153] and 3.3% [n = 83], respectively); the incidence of heart failure AEs for linagliptin- and placebo-treated patients was 0.2% (n = 11) and 0.3% (n = 7), respectively. Overall, linagliptin was weight neutral. Occurrence of investigator-defined hypoglycemic AEs was low for both linagliptin and placebo (11.5% vs 14.0%). In patients receiving concomitant sulfonylurea therapy, investigator-defined hypoglycemic AEs were more frequent with linagliptin versus placebo (22.1% [238/1079] vs 14.5% [61/421], respectively). Subgroup analyses showed similar frequencies of AEs for linagliptin- and placebo-treated patients across different age groups and renal function levels.

IMPLICATIONS

This updated and expanded pooled, post hoc analysis of 22 placebo-controlled trials of linagliptin 5 mg daily supports previous findings of the acceptable overall safety/tolerability profile of linagliptin when administered to a broad range of patients with T2DM. Linagliptin-treated patients demonstrated a low overall risk of hypoglycemia (risk increased by concomitant sulfonylurea therapy). As with all pooled analyses, this study is limited by the use of data from different studies, and the relatively short duration of some included studies, although use of individual patient data from consistently designed trials should minimize methodological differences between trials. Results from ongoing clinical trials will provide additional insight into the long-term safety/tolerability of linagliptin.

Dipeptidyl peptidase-4 inhibitors and heart failure: a meta-analysis of randomized clinical trials

BACKGROUND & AIMS

Recently, the SAVOR TIMI-53 (Saxagliptin Assessment of Vascular Outcomes Recorded in patients with diabetes mellitus--Thrombolysis in Myocardial Infarction-53) reported a significant increase in the risk of hospitalizations for heart failure in patients treated with saxagliptin in comparison with placebo. Aim of the present meta-analysis is the systematic collection and synthesis of information on treatment-emergent cases of acute heart failure described in randomized clinical trials with DPP4.

DATA SOURCES

An extensive Medline, Embase, and Cochrane Database search for "vildagliptin", "sitagliptin", "saxagliptin", "alogliptin", "linagliptin", and "dutogliptin" was performed, collecting all randomized clinical trials on humans up to October 1st, 2013. Studies were included if they satisfied the following criteria: i) randomized trials, ii) duration ≥24 weeks; iii) on type 2 diabetes; iv) comparison of DPP4i with placebo or active drugs. The principal outcome was the effect of DPP4i on the incidence of acute heart failure. A total of 84 eligible trials was identified. The overall risk of acute heart failure was higher in patients treated with DPP4i in comparison with those treated with placebo/active comparators (MH-OR: 1.19[1.03; 1.37]; p = 0.015). When trials with non-cardiovascular outcomes were analysed separately no signal of risk was detectable.

CONCLUSION

Available data from RCTs suggest that DPP4i could be associated with an increased risk of heart failure, without any clear evidence of differences among drugs of the class. Although it is plausible that the risk is greater in some sub-populations of patients, current evidence is not yet sufficient to identify susceptible patients.

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.

Meta-analysis of the cardiovascular outcomes with dipeptidyl peptidase 4 inhibitors: validation of the current FDA mandate

BACKGROUND

Earlier meta-analyses have demonstrated a significant reduction in major adverse cardiovascular events (MACE) with dipeptidyl peptidase 4-inhibitor (DPPI) use, as compared with placebo or alternative anti-diabetic therapies. However, the large phase III/IV trials, namely SAVOR-TIMI 53 and the EXAMINE trials, failed to demonstrate any significant differences in MACE between DPPI and placebo. We aimed to perform an updated meta-analysis of randomized controlled trials (RCTs) to investigate the differences in cardiovascular death, myocardial infarction (MI), and stroke between DPPI and placebo/alternative agents.

METHODS

We searched the MEDLINE, EMBASE, and Cochrane databases for relevant phase III/IV RCTs. Unpublished trials with results available on national clinical trials registers were also included. RCTs with follow-up duration ≥24 weeks were included if they compared DPPI with placebo or an alternative anti-diabetic agent.

RESULTS

A total of 82 RCTs including 73,678 patients were included. We did not observe any significant difference in the pooled odds of cardiovascular death, MI, or stroke in the composite DPPI arm as compared with the control arm. Similarly, the pooled odds of all-cause death and MACE were statistically similar between the two groups. None of the clinical outcomes studied demonstrated evidence of statistical heterogeneity or publication bias. Due to a larger sample size and a longer duration of follow-up, both SAVOR-TIMI 53 and EXAMINE trials had a considerably larger contribution to the pooled estimates in our meta-analysis, driving the updated pooled estimates towards null for all clinical outcomes assessed.

CONCLUSIONS

DPPI use was not associated with increased incidence of cardiovascular mortality, MI, stroke, or MACE compared with placebo or alternative anti-diabetic agents.

Linagliptin treatment in subjects with type 2 diabetes with and without mild-to-moderate renal impairment

AIMS

Renal disease is a frequent comorbidity of type 2 diabetes mellitus (T2DM) and an important factor complicating the choice of glucose-lowering drugs. The aim of this analysis was to evaluate the efficacy and safety of the dipeptidyl peptidase (DPP)-4 inhibitor linagliptin (5 mg/day) in mono, dual or triple oral glucose-lowering regimens in subjects with T2DM and mild or moderate renal impairment (RI).

METHODS

In this pooled analysis of three 24-week, placebo-controlled, phase 3 trials, subjects with mild (estimated glomerular filtration rate (eGFR) 60-<90 ml/min/1.73 m(2) , n = 838) or moderate RI (30-<60 ml/min/1.73 m(2), n = 93) were compared with subjects with normal renal function (≥90 ml/min/1.73 m(2), n = 1212).

RESULTS

Subjects with RI were older, had longer duration of diabetes, and increased prevalence of diabetes-related comorbidities. After 24 weeks, linagliptin achieved consistent placebo-corrected mean glycated haemoglobin (HbA1c) changes across the three renal function categories: normal (-0.63%; p < 0.0001), mild RI (-0.67%; p < 0.0001) and moderate RI (-0.53%; p < 0.01), with no inter-group difference (p = 0.74). Renal function with linagliptin remained stable across all categories. In linagliptin-treated subjects, overall adverse event (AE) rates and serious AE rates were similar to placebo. The incidence of hypoglycaemia with linagliptin and placebo was 11.1 versus 6.9%, 11.9 versus 9.0% and 15.9 versus 12.0% in the normal, mild RI and moderate RI categories, respectively.

CONCLUSIONS

This pooled analysis provides evidence that linagliptin is an effective, well-tolerated and convenient treatment in subjects with T2DM and mild or moderate RI.

Linagliptin: from bench to bedside

PURPOSE

The nature of biomedical research affords a broad range of investigational topics at the preclinical stage, not all of which may be explored in subsequent clinical studies. To provide a comprehensive perspective on the physiologic effects of the dipeptidyl peptidase-4 inhibitor linagliptin, this review will discuss the results of both preclinical and clinical research, summarizing data describing outcomes associated with its use.

SUMMARY

Clinical studies demonstrate an overall favorable safety profile, low risk for hypoglycemia, weight neutrality, primarily nonrenal clearance, and efficacy for glycosylated hemoglobin reduction, typically ranging from 0.6% to 0.8% depending on baseline levels. In addition to these characteristics, preclinical research on linagliptin has yielded several interesting findings such as improved wound healing, reduced hepatic fat content, decreased infarct size following myocardial infarction or intracranial stroke, and improved vascular function with decreased oxidative stress. In accordance with its preclinical profile, linagliptin is unique among available dipeptidyl peptidase-4 compounds because it does not require dose adjustment when used in patients with renal dysfunction. Reduction of albuminuria with linagliptin on top of inhibitors of the renin-angiotensin-aldosterone system in both preclinical and post hoc clinical analysis serves as the foundation for ongoing clinical trials.

CONCLUSION

In addition to its efficacy for glycemic control, current literature points to other potential opportunities associated with linagliptin therapy. These results warrant further investigation and underscore the importance of translational study based on findings from preclinical research. Moving forward, we can expect that future research on linagliptin and other incretin-based therapies will continue to expand their applications beyond the maintenance of glycemic control in patients with type 2 diabetes.

The safety of dipeptidyl peptidase-4 (DPP-4) inhibitors or sodium-glucose cotransporter 2 (SGLT-2) inhibitors added to metformin background therapy in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

The aim of the present meta-analysis was to assess the safety profile of dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium-glucose cotransporter 2 (SGLT-2) inhibitors in comparison with placebo as add-on to metformin therapy in patients with type 2 diabetes. Randomized controlled trials and controlled clinical trials were identified by searching Pubmed, Embase and the Cochrane Central Register of Controlled Trials database until 15 July 2013. All included studies were critically appraised and analysed with the use of Review Manager 5.1.0 software according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement protocol. Twenty randomized and double-blinded studies published in 22 articles fulfilled the inclusion criteria for meta-analysis. The overall results demonstrated that the use of oral antidiabetic agents (analysed separately and together) was not associated with any significantly increased risk of any serious adverse events including hypoglycaemia and gastrointestinal disorders. Moreover, the use of DPP-4 or SGLT-2 inhibitors significantly decreased risk of diarrhoea compared with placebo, when given concomitantly with metformin. However, we found that the SGLT-2 inhibitors were more likely to cause a genital infection. Despite some limitations, the findings of this meta-analysis indicate that DPP-4 or SGLT-2 inhibitors have favourable safety profile, and such therapy, when combined with metformin is well tolerated.

Novel hydrazine derivatives as selective DPP-IV inhibitors: findings from virtual screening and validation through molecular dynamics simulations

The present study demonstrates and validates the discovery of two novel hydrazine derivatives as selective dipeptidyl peptidase-IV (DPP-IV) inhibitors. Virtual screening (VS) of publicly available databases was performed using virtual screening workflow (VSW) of Schrödinger software against DPP-IV and the most promising hits were selected. Selectivity was further assessed by docking the hits against homology modeled structures of DPP8 and DPP9. Two novel hydrazine derivatives were selected for further studies based on their selectivity threshold. To assess their correct binding modes and stability of their complexes with enzyme, molecular dynamic (MD) simulation studies were performed against the DPP-IV protein and the results revealed that they had a better binding affinity towards DPP-IV as compared to DPP 8 and DPP 9. The binding poses were further validated by docking these ligands with different softwares (Glide and Gold). The proposed binding modes of hydrazines were found to be similar to sitagliptine and alogliptine. Thus, the study reveals the potential of hydrazine derivatives as highly selective DPP-IV inhibitors.

The long-term efficacy and safety of DPP-IV inhibitors monotherapy and in combination with metformin in 18,980 patients with type-2 diabetes mellitus--a meta-analysis

PURPOSE

To assess the long-term efficacy and safety of DPP-IV inhibitors therapy versus comparators in patients with T2DM.

METHODS

A comprehensive search for randomized controlled trials (RCTs; ≥24 weeks) was performed. RCTs had to compare DPP-IV inhibitors therapy with placebo, metformin and sulphonylureas + metformin. Inverse variance mean difference (IV-MD) with 95%CI was calculated for the mean HbA1c changes (%) from baseline to (imputed) endpoint. Mantel-Haenszel odds ratio (MH-OR) with 95%CI was calculated for side reactions.

RESULTS

Twenty-three RCTs were included. The mean HbA1c changes (%) were as follows: IV-MD, 95%CI = -0.35 [-0.51, -0.19], p < 0.0001 for DPP-IV inhibitors therapy versus comparators, and IV-MD, 95%CI = 0.11 [0.04, 0.18], p = 0.002 for DPP-IV inhibitors + met versus su + met. For hypoglycaemia, MH-OR, 95%CI = 0.13 [0.09, 0.19], p < 0.00001(DPP-IV inhibitors + met vs. su + met). For diarrhoea, MH-OR, 95%CI = 0.77 [0.64, 0.93], p = 0.008 (DPP-IV inhibitors + met vs. met). By comparing DPP-IV inhibitors therapy with comparators, we found 95%CI = 0.00 [-0.01, 0.01], p = 0.49, for the upper respiratory tract infection MH-OR; 95%CI = 0.97 [0.70, 1.34], p = 0.83 for the urinary tract infection MH-OR; and 95%CI = 1.07 [0.94, 1.21], p = 0.30 for nasopharyngitis MH-OR.

CONCLUSIONS

DPP-IV inhibitors could achieve a long-term effective and safe glycaemic control for use as monotherapy or in combination with metformin. They have low incidences of hypoglycaemia and gastrointestinal side effects. There is no evidence that DPP-IV inhibitors increase the risk of infections.

Optimal therapy of type 2 diabetes: a controversial challenge

Type 2 diabetes mellitus (T2DM) is one of the most common chronic disorders in older adults and the number of elderly diabetic subjects is growing worldwide. Nonetheless, the diagnosis of T2DM in elderly population is often missed or delayed until an acute metabolic emergency occurs. Accumulating evidence suggests that both aging and environmental factors contribute to the high prevalence of diabetes in the elderly. Clinical management of T2DM in elderly subjects presents unique challenges because of the multifaceted geriatric scenario. Diabetes significantly lowers the chances of "successful" aging, notably it increases functional limitations and impairs quality of life. In this regard, older diabetic patients have a high burden of comorbidities, diabetes-related complications, physical disability, cognitive impairment and malnutrition, and they are more susceptible to the complications of dysglycemia and polypharmacy. Several national and international organizations have delivered guidelines to implement optimal therapy in older diabetic patients based on individualized treatment goals. This means appreciation of the heterogeneity of the disease as generated by life expectancy, functional reserve, social support, as well as personal preference. This paper will review current treatments for achieving glycemic targets in elderly diabetic patients, and discuss the potential role of emerging treatments in this patient population.

Insulin plus incretin: A glucose-lowering strategy for type 2-diabetes

There are many advantages of combining incretin therapy [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] with insulin therapy as a glucose-lowering strategy in type 2 diabetes. One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy. Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin. Several clinical trials have studied the addition of GLP-1 receptor agonists [exenatide BID (twice daily), lixisenatide, albiglutide] or DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, alogliptin, linagliptin) to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist (liraglutide). These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin. This article reviews the background and clinical studies on this combination.

Systematic review and meta-analysis of efficacy and safety of combinational therapy with metformin and dipeptidyl peptidase-4 inhibitors

Combinational therapies are often required in the management of type 2 diabetes mellitus (T2DM). Among the important candidates, dipeptidyl peptidase-4 inhibitors (DPPIs) and metformin combination (DPPI-MET) have shown promising endeavors. In order to examine the efficacy and safety of such a combination therapy in T2DM patients finding inadequate control with metformin, this systematic review and meta-analysis has been conducted. Literature search was made in multiple electronic databases. Inclusion criteria included; RCTs examining the efficacy and safety of DPPI-MET against placebo-MET or MET-only groups of T2DM patients by observing changes in disease endpoints including HbA1c and FPG, and the length of trial be at least 12 weeks. Mean differences based meta-analyses were performed and heterogeneity assessment was carried out. Nineteen studies were selected and included in the meta-analyses. DPPI-MET significantly improved all disease endpoints and the difference could be noticed up to 2 years in the majority of outcome measures. In comparison with PBO-MET, the DPPI-MET combinational therapy resulted in the percent HbA1c changes from baseline with a mean difference [95% CI] of −0.77 [−0.86, −0.69] in 3-month (P < 0.00001), −0.67 [−0.76, −0.59] in 6-month (P < 0.00001), −0.67 [−0.88, −0.47] in 1-year (P < 0.00001) and −0.36 [−0.53, −0.20] in 2-year trials (P < 0.0003). Reduction in body weight and safety profile in the treated and control groups were not different. A combinational therapy with DPPI and metformin significantly improves diabetes clinical indicators and this effect has been observed for up to 2 years herein. Safety and tolerability of DPPI-MET combination have been found well-manageable with a very similar adverse event profile in both treated and control groups.

Dipeptidyl peptidase-4 inhibitors as a third-line oral antihyperglycaemic agent in patients with type 2 diabetes mellitus: the impact of ethnicity

Aims. The aim of this study is to examine the efficacy of adding a dipeptidyl peptidase-4 (DPP-4) inhibitor to patients with type 2 diabetes inadequately controlled by metformin and sulphonylurea combination treatment. The response of Asian and non-Asian patients to this regimen was also examined. Methods. The medical and computerized records of 80 patients were examined. These patients had baseline HbA1c levels ranging from 7.0 to 12.5% and had a DPP-4 inhibitor add-on therapy for a minimum period of 12 weeks. The primary endpoint was the change in HbA1c level before and after DPP-4 inhibitor treatment. Results. During oral triple therapy, there was a reduction of HbA1c from 8.3% (7.7-8.9) to 7.2% (6.8-7.6) and 26 patients (32.5%) achieved an HbA1c <7%. Poor baseline glycaemic control, lower BMI, and younger age were associated with a better response, but duration of diabetes and gender did not affect outcome. The HbA1c reduction was not different between Asians and non-Asians group [-1.00% (0.6-1.3) vs -0.90% (0.4-1.6)]. Conclusions. DPP-4 inhibitor as a third-line add-on therapy can achieve significant glycaemic improvement in patients with type 2 diabetes inadequately controlled on the combination of metformin and sulphonylurea. The improvement in HbA1c was similar between Asian and non-Asian patients.

Efficacy and safety of dipeptidyl peptidase-4 inhibitors and metformin as initial combination therapy and as monotherapy in patients with type 2 diabetes mellitus: a meta-analysis

AIMS

This meta-analysis was performed to provide an update on the efficacy and safety of dipeptidyl peptidase-4 (DPP-4) inhibitors and metformin as initial combination therapy and as monotherapy in patients with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a search on MEDLINE, Embase and Cochrane Collaborative database for randomized controlled trials (RCTs) of DPP-4 inhibitors and metformin as initial combination therapy or as monotherapy in patients with T2DM by the end of December 2012, using the key words 'alogliptin', 'dutogliptin', 'linagliptin', 'saxagliptin', 'sitagliptin', 'vildagliptin' and 'metformin'. RCTs were selected for meta-analysis if (1) they were RCTs comparing DPP-4 inhibitors plus metformin as initial combination therapy or DPP-4 inhibitor monotherapy to metformin monotherapy, (2) duration of treatment was ≥12 weeks and (3) reported data on haemoglobin A1c (HbA1c) change, fasting plasma glucose (FPG) change, weight change, adverse cardiovascular (CV) events, hypoglycaemia or gastrointestinal adverse events (AEs).

RESULTS

A total of eight RCTs were included. Compared with metformin monotherapy, DPP-4 inhibitors monotherapy was associated with lower reduction in HbA1c level [weighted mean differences (MD) = 0.28, 95% confidence intervals (CIs) (0.17, 0.40), p < 0.00001], lower reduction in FPG level [MD = 0.81, 95% CI(0.60, 1.02), p <0.00001], lower weight loss [MD = 1.51, 95% CI (0.89, 2.13), p < 0.00001], but lower risk of adverse CV events [risk ratio (RR) = 0.36, 95% CI (0.15, 0.85), p = 0.02], lower risk of hypoglycaemia [RR = 0.44, 95% CI (0.27, 0.72), p = 0.001] and lower risk of gastrointestinal AEs [RR = 0.63, 95% CI(0.55, 0.70), p <0.00001]. Compared with metformin monotherapy, DPP-4 inhibitors plus metformin as initial combination therapy was associated with higher reduction in HbA1c level [MD = -0.49, 95% CI (-0.57, -0.40), p < 0.00001], higher reduction in FPG level [MD = -0.80, 95% CI (-0.87, -0.74), p < 0.00001], lower weight loss [MD = 0.44, 95% CI (0.22, 0.67), p = 0.0001]; but was not associated with a further reduction in adverse CV events [RR=0.54, 95% CI (0.25, 1.19), p = 0.13], nor the higher risk of hypoglycaemia [RR = 1.04, 95% CI (0.72, 1.50), p = 0.82], nor the prolonged risk of gastrointestinal AEs [RR = 0.98, 95% CI (0.88, 1.10), p = 0.77].

CONCLUSIONS

DPP-4 inhibitors, which are safe and effective in controlling the blood glucose, may possibly decrease the risk of CV events in patients with T2DM. It could be a credible alternative for T2DM patients who, for some reason, cannot use metformin, or are in high risk of CV exposure. High-quality, large sample and long-term follow-up clinical trails are needed to confirm the long-term conclusions.

Efficacy and safety of linagliptin in Hispanic/Latino patients with type 2 diabetes mellitus: a pooled analysis from six randomized placebo-controlled phase 3 trials

OBJECTIVE

The number of individuals diagnosed with type 2 diabetes mellitus is expected to rise disproportionately in Hispanic/Latino populations. We therefore aimed to assess the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin specifically in Hispanic/Latino patients with type 2 diabetes mellitus.

RESEARCH DESIGN AND METHODS

Data from 745 patients who self-identified their ethnicity as Hispanic or Latino were pooled from six randomized, placebo-controlled phase 3 trials. Participants received linagliptin (5 mg/day) or placebo as monotherapy, or in combination with other oral antidiabetes drugs for 18 or 24 weeks.

RESULTS

The placebo-adjusted mean change (95% CI) in glycated hemoglobin from baseline (mean 8.2%) was -0.63% (-0.77 to -0.48; p<0.0001) at week 18, and -0.58% (-0.74 to -0.42; p<0.0001) at week 24. The placebo-adjusted mean change (95% CI) in fasting plasma glucose from baseline was -11.7 mg/dL (-19.3 to -4.0; p=0.0028) at week 18 and -14.1 mg/dL (-22.0 to -6.3; p=0.0004) at week 24. Hypoglycemia incidence was 17.4% with linagliptin and 21% with placebo. In patients not receiving concomitant sulfonylurea, the hypoglycemia incidence was 10.1% with linagliptin and 19.4% with placebo. The overall incidence of adverse events (AEs), drug-related AEs, and serious AEs with linagliptin was similar to placebo (AEs 67.6% vs 68.9%; drug-related AEs 15.1% vs 18.7%; serious AEs 3.6% vs 3.0%). The mean body weight remained unchanged in both groups.

CONCLUSIONS

In Hispanic/Latino patients with inadequately controlled type 2 diabetes mellitus, linagliptin provided clinically meaningful improvements in glycemic control without weight gain or increased risk of hypoglycemia.

Linagliptin added to sulphonylurea in uncontrolled type 2 diabetes patients with moderate-to-severe renal impairment

Glucose-lowering treatment options are limited for uncontrolled type 2 diabetes mellitus (T2DM) patients with advanced stages of renal impairment (RI). This retrospective analysis evaluated glycaemic efficacy and tolerability of the dipeptidyl peptidase-4 inhibitor linagliptin added to sulphonylurea. Three randomized phase 3 studies (n = 619) including T2DM subjects with moderate or severe RI [estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²] were analysed; only sulphonylurea-treated subjects who received additional linagliptin (n = 58) or placebo (n = 33) were evaluated. Linagliptin provided meaningful placebo-adjusted HbA1c reductions of -0.68% (95% confidence interval: -1.19, -0.17), -1.08% (-2.02, -0.14) and -0.62% (-1.25, 0.01) after 24, 18 and 12 weeks, respectively. There was a similar incidence of overall adverse events (linagliptin: 79.3%, placebo: 75.8%) and hypoglycaemia (linagliptin: 37.9%, placebo: 39.4%). Severe hypoglycaemia was more common with placebo (linagliptin: 1.7%, placebo: 6.1%). These data suggest that linagliptin is a safe and effective glucose-lowering treatment in T2DM patients with moderate-to-severe RI for whom sulphonylurea treatment is no longer sufficient.

Pathogenesis and management of postprandial hyperglycemia: role of incretin-based therapies

Postprandial plasma glucose concentrations are an important contributor to glycemic control. There is evidence suggesting that postprandial hyperglycemia may be an independent risk factor for cardiovascular disease. Glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are antidiabetic agents that predominantly reduce postprandial plasma glucose levels. DPP-4 inhibitors are associated with fewer gastrointestinal side effects than GLP-1 receptor agonists and are administered orally, unlike GLP-1 analogs, which are administered as subcutaneous injections. GLP-1 receptor agonists are somewhat more effective than DPP-4 inhibitors in reducing postprandial plasma glucose and are usually associated with significant weight loss. For these reasons, GLP-1 receptor agonists are generally preferred over DPP-4 inhibitors as part of combination treatment regimens in patients with glycated hemoglobin levels above 8.0%. This article reviews the pathogenesis of postprandial hyperglycemia, the mechanisms by which GLP-1 receptor agonists and DPP-4 inhibitors reduce postprandial plasma glucose concentrations, and the results of recent clinical trials (ie, published 2008 to October 2012) that evaluated the effects of these agents on postprandial plasma glucose levels when evaluated as monotherapy compared with placebo or as add-on therapy to metformin, a sulfonylurea, or insulin. Findings from recent clinical studies suggest that both GLP-1 receptor agonists and DPP-4 inhibitors could become valuable treatment options for optimizing glycemic control in patients unable to achieve glycated hemoglobin goals on basal insulin, with the added benefits of weight loss and a low risk of hypoglycemia.

Initial combination of linagliptin and metformin in patients with type 2 diabetes: efficacy and safety in a randomised, double-blind 1-year extension study

OBJECTIVE

To determine the efficacy and safety of linagliptin in initial combination with metformin in patients with type 2 diabetes.

METHODS

This 1-year randomised, double-blind study was an extension of a 6-month randomised controlled trial, in which adults with type 2 diabetes received one of six treatment regimens (linagliptin 2.5 mg plus metformin 500 mg bid, linagliptin 2.5 mg plus metformin mg 1000 bid, metformin 1000 mg bid, metformin 500 mg bid, linagliptin 5 mg qd or placebo). In the extension, patients in the first three treatment groups continued their regimen (non-switched group, n = 333) while the metformin 500 mg bid, linagliptin 5 mg qd and placebo groups were re-randomised to one of the three continuing regimens (switched group, n = 233).

RESULTS

All three non-switched groups maintained reductions in glycosylated haemoglobin (HbA1c; mean ± standard deviation reductions across the 1.5-year period: linagliptin 2.5 plus metformin 1000 bid, -1.63 ± 1.05%; linagliptin 2.5 plus metformin 500 bid, -1.32 ± 1.06%; metformin 1000 bid, -1.25 ± 0.91%) while the switched groups showed additional HbA1c reductions. During the extension, there were no clinically meaningful changes in body weight in any group. Adverse event rates were similar between groups, with most events being mild or moderate, and the incidence of investigator-defined hypoglycaemia was low, with no severe events.

DISCUSSION

Initial combination of linagliptin and metformin was well tolerated over the 1-year extension period, with low risk of hypoglycaemia, and improved glycaemic control vs. metformin alone.

CONCLUSION

The initial combination of linagliptin and metformin appears to provide a useful treatment option in patients whose blood glucose levels are increased to an extent that metformin monotherapy may not achieve treatment targets.

Incretin-based therapies: focus on effects beyond glycemic control alone

Type 2 diabetes is associated with a high prevalence of comorbidities resulting from hypertension, dyslipidemia, and hyperglycemia. Inadequate management of these risk factors will eventually result in detrimental health consequences. Thus, the effect of a drug on factors such as weight, cardiovascular (CV) risk factors, and adherence is important to consider. A review was undertaken of the recent medical literature describing the extraglycemic characteristics of the two classes of incretin-based therapies-glucagon-like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 (DPP-4) inhibitors. PubMed searches were performed to identify published data on incretin therapies that describe their effects on CV risk factors, CV events, and factors related to medication adherence. The maintenance or loss of weight associated with the use of GLP-1RAs and DPP-4 inhibitors is well described in the medical literature. These agents also appear to be associated with a modest decrease in blood pressure and a reduced risk of CV events. In addition, several characteristics of incretin therapies may improve rates of medication adherence, such as generally favorable tolerability profiles (particularly with DPP-4 inhibitors), the availability of formulations that simplify treatment regimens, and a low risk for hypoglycemia. The literature on incretin therapies describes a number of clinical characteristics that are relevant to the management of extraglycemic risk factors. As part of a holistic treatment strategy, these properties constitute important considerations for tailoring therapy to individual patients with type 2 diabetes.

Linagliptin lowers albuminuria on top of recommended standard treatment in patients with type 2 diabetes and renal dysfunction

OBJECTIVE

Preclinical data suggest that linagliptin, a dipeptidyl peptidase-4 inhibitor, may lower urinary albumin excretion. The ability of linagliptin to lower albuminuria on top of renin-angiotensin-aldosterone system (RAAS) inhibition in humans was analyzed by pooling data from four similarly designed, 24-week, randomized, double-blind, placebo-controlled, phase III trials.

RESEARCH DESIGN AND METHODS

A pooled analysis of four completed studies identified 217 subjects with type 2 diabetes and prevalent albuminuria (defined as a urinary albumin-to-creatinine ratio [UACR] of 30-3,000 mg/g creatinine) while receiving stable doses of RAAS inhibitors. Participants were randomized to either linagliptin 5 mg/day (n = 162) or placebo (n= 55). The primary end point was the percentage change in geometric mean UACR from baseline to week 24.

RESULTS

UACR at week 24 was reduced by 32% (95% CI -42 to -21; P < 0.05) with linagliptin compared with 6% (95% CI -27 to +23) with placebo, with a between-group difference of 28% (95% CI -47 to -2; P = 0.0357). The between-group difference in the change in HbA1c from baseline to week 24 was -0.61% (-6.7 mmol/mol) in favor of linagliptin (95% CI -0.88 to -0.34% [-9.6 to -3.7 mmol/mol]; P < 0.0001). The albuminuria-lowering effect of linagliptin, however, was not influenced by race or HbA1c and systolic blood pressure (SBP) values at baseline or after treatment.

CONCLUSIONS

Linagliptin administered in addition to stable RAAS inhibitors led to a significant reduction in albuminuria in patients with type 2 diabetes and renal dysfunction. This observation was independent of changes in glucose level or SBP. Further research to prospectively investigate the renal effects of linagliptin is underway.

Linagliptin for patients aged 70 years or older with type 2 diabetes inadequately controlled with common antidiabetes treatments: a randomised, double-blind, placebo-controlled trial

BACKGROUND

A substantial proportion of patients with type 2 diabetes are elderly (≥65 years) but this group has been largely excluded from clinical studies of glucose-lowering drugs. We aimed to assess the effectiveness of linagliptin, a dipeptidyl peptidase-4 inhibitor, in elderly patients with type 2 diabetes.

METHODS

In this randomised, double-blind, parallel-group, multinational phase 3 study, patients aged 70 years or older with type 2 diabetes, glycated haemoglobin A1c (HbA1c) of 7·0% or more, receiving metformin, sulfonylureas, or basal insulin, or combinations of these drugs, were randomised (by computer-generated randomisation sequence, concealed with a voice-response system, stratified by HbA1c level [<8·5% vs ≥8·5%] and insulin use [yes vs no], block size four) in a 2:1 ratio to once-daily oral treatment with linagliptin 5 mg or matching placebo for 24 weeks. Investigators and participants were masked to assignment throughout the study. The primary endpoint was change in HbA1c from baseline to week 24. This trial is registered with ClinicalTrials.gov, number NCT01084005.

FINDINGS

241 community-living outpatients were randomised (162 linagliptin, 79 placebo). Mean age was 74·9 years (SD 4·3). Mean HbA1c was 7·8% (SD 0·8). At week 24, placebo-adjusted mean change in HbA1c with linagliptin was -0·64% (95% CI -0·81 to -0·48, p<0·0001). Overall safety and tolerability were much the same between the linagliptin and placebo groups; 75·9% of patients in both groups had an adverse event (linagliptin n=123, placebo n=60). No deaths occurred. Serious adverse events occurred in 8·6% (14) of patients in the linagliptin group and 6·3% (five) patients in the placebo group; none were deemed related to study drug. Hypoglycaemia was the most common adverse event in both groups, but did not differ between groups (24·1% [39] in the linagliptin group, 16·5% [13] in the placebo group; odds ratio 1·58, 95% CI 0·78-3·78, p=0·2083).

INTERPRETATION

In elderly patients with type 2 diabetes linagliptin was efficacious in lowering glucose with a safety profile similar to placebo. These findings could inform treatment decisions for achieving individualised glycaemic goals with minimal risk in this important population of patients.

FUNDING

Boehringer Ingelheim.

Novel therapies for the management of type 2 diabetes mellitus: Part 2. Addressing the incretin defect in the clinical setting in 2013

The present short review summarizes and updates clinical experience with two classes of drugs introduced for the management of type 2 diabetes mellitus over the past 8 years: (i) the glucagon-like peptide-1 receptor agonists; and (ii) the dipeptidyl peptidase 4 inhibitors. Both classes of agents address the so called "incretin defect" in patients with T2DM.

Linagliptin provides effective, well-tolerated add-on therapy to pre-existing oral antidiabetic therapy over 1 year in Japanese patients with type 2 diabetes

AIMS

To evaluate the long-term safety and efficacy of linagliptin as add-on therapy to one approved oral antidiabetic drug (OAD) in Japanese patients with type 2 diabetes mellitus and insufficient glycaemic control.

METHODS

This 52-week, multicentre, open-label, parallel-group study evaluated once-daily linagliptin 5 mg as add-on therapy to one OAD [biguanide, glinide, glitazone, sulphonylurea (SU) or α-glucosidase inhibitors (A-GI)] in 618 patients. After a 2-week run-in, patients on SU or A-GI were randomized to either linagliptin (once daily, 5 mg) or metformin (twice or thrice daily, up to 2250 mg/day) as add-on therapy. Patients receiving the other OADs received linagliptin add-on therapy (non-randomized).

RESULTS

Adverse events were mostly mild or moderate, and rates were similar across all groups. Hypoglycaemic events were rare, except in the SU group. Overall, 26 (5.8%) hypoglycaemic events were reported in patients receiving linagliptin (non-randomized). Hypoglycaemic events were similar for linagliptin and metformin added to A-GI (1/61 vs. 2/61, respectively) or SU (17/124 vs. 10/63, respectively). Significant reductions in glycated haemoglobin (HbA1c) levels (between -0.7 and -0.9%) occurred throughout the study period for the background therapy groups that received linagliptin (baseline HbA1c 7.9-8.1%). The decline in HbA1c levels was indistinguishable between linagliptin and metformin groups when administered as add-on therapy to A-GI or SU.

CONCLUSIONS

Once-daily linagliptin showed safety and tolerability over 1 year and provided effective add-on therapy leading to significant HbA1c reductions, similar to metformin, over 52 weeks in Japanese patients.

Clinical utility of the dipeptidyl peptidase-4 inhibitor linagliptin

INTRODUCTION

Dipeptidyl peptidase-4 (DPP-4) inhibitors have emerged as new options in the management of type 2 diabetes mellitus, demonstrating meaningful antihyperglycemic effects and good tolerability profiles. Glycemic control is improved by preventing the DPP-4-mediated degradation of incretin hormones, with a resulting increase in insulin secretion and inhibition of glucagon secretion.

PURPOSE

This article provides a discussion of the clinical utility of linagliptin.

RESULTS AND CONCLUSION

Linagliptin is a xanthine-based, oral DPP-4 inhibitor that has been approved in the United States and Europe. It has been evaluated extensively in clinical trials, and results in improved glycemic control when used as monotherapy, initial combination therapy with metformin or pioglitazone, add-on therapy to metformin and/or a sulfonylurea, or add-on therapy to basal insulin (with or without oral antidiabetic drugs). Consistent with other members of its class, the benefits of linagliptin also include a low risk of hypoglycemia and weight gain. However, linagliptin is the first DPP-4 inhibitor to be approved as a once-daily, 5-mg dose and, due to its primarily non-renal route of excretion, no dosage adjustment is required for patients with renal or hepatic impairment. The pharmacokinetics and pharmacodynamics of linagliptin are not affected to a clinically meaningful degree by race or ethnicity and linagliptin has very low potential for drug-drug interactions.

Liraglutide achieves A1C targets more often than sitagliptin or exenatide when added to metformin in patients with type 2 diabetes and a baseline A1C <8.0%

OBJECTIVE

Compare the safety and efficacy of liraglutide to that of sitagliptin or exenatide as add-on to metformin in patients with type 2 diabetes (T2D) and glycated hemoglobin (A1C) <8.0%.

METHODS

Post hoc analysis of 26-week data from liraglutide 1.8 mg once daily (OD) versus exenatide 10 μg twice daily (LEAD-6) and liraglutide 1.8 mg OD versus sitagliptin 100 mg OD (LIRA-DPP-4); only patients treated as add-on to metformin with baseline A1C <8.0% were included. Efficacy analysis was performed on the intention-to-treat population with missing values imputed by last observation carried forward.

RESULTS

More patients achieved A1C targets (<7.0% and ≤6.5%) with liraglutide versus exenatide or sitagliptin; the difference was greatest for A1C ≤6.5% (LEAD-6: 65% versus 35%; odds ratio [OR]=3.37, 95% confidence interval [CI]: 1.31-8.63; P = .01 or LIRA-DPP-4: 53% versus 19%; OR = 4.78, 95% CI 2.10 to 10.87; P = .0002). Significantly more patients achieved a composite endpoint of A1C <7.0% with no weight gain or hypoglycemia with liraglutide compared with exenatide (78% versus 42%; OR = 4.99, 95% CI: 1.77 to 14.04; P = .0023) or sitagliptin (61% versus 21%; OR = 5.95, 95% CI: 2.66 to 13.29; P<.0001). All treatments were well tolerated, there was no major hypoglycemia and few patients (8 to 10%) experienced minor hypoglycemia.

CONCLUSION

When added to metformin in patients with an A1C <8.0%, more patients using liraglutide 1.8 mg reached A1C targets than with exenatide or sitagliptin. Sitagliptin had particularly low efficacy in this analysis. These data support the use of liraglutide 1.8 mg as a safe and effective alternative to sitagliptin or exenatide following metformin failure in patients with an A1C <8.0%.

New and Future Medications for the Treatment of Type 2 Diabetes Mellitus

With almost 30 million individuals predicted to be diagnosed by the year 2025, type 2 diabetes mellitus (T2DM) has become one of the most prevalent diseases in the United States. Because of the progressive dysfunction of the pancreatic β-cells and increasing insulin resistance over time, the need for treatments with different mechanisms or addition of medications to a regimen is becoming commonplace. Because of this, developing new medications to treat T2DM has been the focus of a lot of recent research and drug development. Molecular substrates such as glucagon-like peptide-1 (GLP-1), dipeptidyl peptidase-4 (DPP-4), and the sodium glucose transporter-2 (SGLT2) have all become new therapeutic targets. GLP-1 agonists and DPP-4 inhibitors are 2 of the newest classes of Food and Drug Administration–approved medications for diabetes. By increasing GLP-1 to supraphysiologic levels (GLP-1 agonists) and delaying endogenous GLP-1 degradation (DPP-4 inhibitors), these drugs increase insulin secretion and decrease glucagon production. SGLT2 inhibitors, the newest antihyperglycemic class, promote glycosuria by inhibiting sodium and glucose reabsorption in the proximal tubule of the renal nephron. Other novel agents for the treatment of diabetes include the use of the dopamine agonist bromocriptine, the cholesterol medication colesevelam, and a new form of inhaled insulin.

Efficacy and safety of linagliptin added to metformin and sulphonylurea in Chinese patients with type 2 diabetes: a sub-analysis of data from a randomised clinical trial

OBJECTIVES

To evaluate the efficacy and safety of linagliptin in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin and sulphonylurea.

RESEARCH DESIGN AND METHODS

Data for a pre-defined Chinese subgroup who participated in a Phase III randomised, placebo-controlled, 24 week trial (NCT00602472) were analysed. The primary endpoint was change in HbA1c from baseline to 24 weeks. Apart from safety endpoints, secondary endpoints included changes in FPG and measures of insulin secretion and resistance.

RESULTS

A total of 192 Chinese patients with T2DM participated in the pre-defined analysis; 144 and 48 patients received linagliptin or placebo, respectively, added to metformin and sulphonylurea. Baseline characteristics (mean [±SD]) for linagliptin and placebo were similar: HbA1c: 8.1% (±0.85) and 8.1% (±0.84); body mass index: 25.9 (±3.2) and 25.6 (±3.4) kg/m², respectively. Placebo-corrected mean (±SE) change in HbA1c from baseline at 24 weeks was -0.68% (0.14) with linagliptin-based treatment (95% CI: -0.96 to -0.39; P<0.0001). Placebo-corrected mean (±SE) change in FPG from baseline at 24 weeks with linagliptin was -18.8 (6.5) mg/dL (-1.0 [0.4] mmol/L; 95% CI: -31.7 to -5.9; P=0.0044). Overall adverse event (AE) rates with linagliptin and placebo including background medication were similar (38.9% and 43.8%, respectively). Drug-related AEs were reported by 12.5% and 2.1% of linagliptin and placebo patients, respectively. Differences were due to hypoglycaemia (10.4% and 0.0%, respectively). No severe hypoglycaemia was reported in either group of this sub-population.

CONCLUSION

Linagliptin in combination with metformin and sulphonylurea has a favourable safety profile and is an efficacious and well tolerated treatment option for Chinese patients with inadequately controlled T2DM. Reduction of sulphonylurea dose should be considered to minimise risk of hypoglycaemia. Although the findings of this pre-specified sub-analysis may be limited by the number of patients in the subgroup, the results were generally consistent with those for the overall population. CLINICALTRIALS IDENTIFIER: NCT00602472.

The DPP-4 inhibitor linagliptin restores β-cell function and survival in human isolated islets through GLP-1 stabilization

CONTEXT

Inhibition of dipeptidyl peptidase-4 (DPP-4) is a potent strategy to increase glucose-dependent insulinotropic polypeptide and glucagon like peptide 1 (GLP-1) induced insulin secretion in diabetes. It is important to know whether new drugs approved for the treatment of type 2 diabetes have direct effects on the β-cell.

OBJECTIVE

Herein we investigated the effect of linagliptin, a novel DPP-4 inhibitor, on β-cell function and survival.

DESIGN

Human islets were exposed to a diabetic milieu (11.1-33.3 mM glucose, 0.5 mM palmitate, the mixture of 2 ng/mL IL-1β+1000 U/mL interferon-γ, or 50 μM H₂O₂) with or without 500 ng/mL IL-1 receptor antagonist (IL-1Ra) or 30-50 nM linagliptin.

RESULTS

Linagliptin restored β-cell function and turnover, which was impaired when islets were exposed to elevated glucose, palmitate, cytokines, or H₂O₂. Pretreatment with IL-1Ra was similarly effective, except against H₂O₂ treatment. Nitrotyrosine concentrations in islet lysates, an indicator of oxidative stress, were highly elevated under diabetic conditions but not in islets treated with linagliptin or IL-1Ra. Linagliptin also reduced cytokine secretion and stabilized GLP-1 in islet supernatants.

CONCLUSIONS

We show that the novel DPP-4 inhibitor linagliptin protected from gluco-, lipo-, and cytokine-toxicity and stabilized active GLP-1 secreted from human islets. This provides a direct GLP-1 mediated protective effect of linagliptin on β-cell function and survival.