Long-term safety of linagliptin monotherapy in Japanese patients with type 2 diabetes

A model-informed approach to accelerate the clinical development of cofrogliptin (HSK7653), a novel ultralong-acting dipeptidyl peptidase-4 inhibitor

AIM

To employ a model-informed drug development approach in facilitating decision making and expediting the clinical progress of cofrogliptin (HSK7653), a novel ultralong-acting dipeptidyl peptidase-4 (DPP-4) inhibitor, for the treatment of type 2 diabetes (T2D) via a biweekly dosing regimen.

METHODS

Firstly, a population pharmacokinetics and pharmacodynamics (PopPKPD) model was developed using PK and PD data from a single ascending dose study to simulate the PK and PD time profiles of HSK7653 after multiple doses. Secondly, model-based meta-analysis (MBMA) was performed on published clinical studies of Eastern Asian subjects for all DPP-4 inhibitors. We hypothesized a consistent relationship between PK and DPP-4 inhibition in both healthy individuals and in those with T2D, establishing a quantitative correlation between DPP-4 inhibition and HbA1c. Finally, the predicted PK/DPP-4 inhibition/HbA1c profiles were validated by T2D patients in late clinical trials.

RESULTS

The PK/DPP-4 inhibition/HbA1c profiles of T2D patients treated with HSK7653 matched the modelled data. Our PopPKPD and MBMA models predict multiple ascending dosing PK and PD characteristics from single ascending dosing data, as well as the long-term efficacy in T2D patients, based on healthy subjects.

CONCLUSIONS

Successful waiver approval for the phase 2b dose-finding study was achieved through model-informed recommendations, facilitating the clinical development of HSK7653 and other DPP-4 inhibitors.

In Silico Development of Combinatorial Therapeutic Approaches Targeting Key Signaling Pathways in Metabolic Syndrome

PURPOSE

Dysregulations of key signaling pathways in metabolic syndrome are multifactorial, eventually leading to cardiovascular events. Hyperglycemia in conjunction with dyslipidemia induces insulin resistance and provokes release of proinflammatory cytokines resulting in chronic inflammation, accelerated lipid peroxidation with further development of atherosclerotic alterations and diabetes. We have proposed a novel combinatorial approach using FDA approved compounds targeting IL-17a and DPP4 to ameliorate a significant portion of the clustered clinical risks in patients with metabolic syndrome. In our current research we have modeled the outcomes of metabolic syndrome treatment using two distinct drug classes.

METHODS

Targets were chosen based on the clustered clinical risks in metabolic syndrome: dyslipidemia, insulin resistance, impaired glucose control, and chronic inflammation. Drug development platform, BIOiSIM™, was used to narrow down two different drug classes with distinct modes of action and modalities. Pharmacokinetic and pharmacodynamic profiles of the most promising drugs were modeling showing predicted outcomes of combinatorial therapeutic interventions.

RESULTS

Preliminary studies demonstrated that the most promising drugs belong to DPP-4 inhibitors and IL-17A inhibitors. Evogliptin was chosen to be a candidate for regulating glucose control with long term collateral benefit of weight loss and improved lipid profiles. Secukinumab, an IL-17A sequestering agent used in treating psoriasis, was selected as a repurposed candidate to address the sequential inflammatory disorders that follow the first metabolic insult.

CONCLUSIONS

Our analysis suggests this novel combinatorial therapeutic approach inducing DPP4 and Il-17a suppression has a high likelihood of ameliorating a significant portion of the clustered clinical risk in metabolic syndrome.

Safety and effectiveness of linagliptin in Korean patients with type 2 diabetes: A postmarketing surveillance study

We designed a postmarketing surveillance study of linagliptin for patients with type 2 diabetes (T2D) in Korea. This prospective, observational, multicentre study investigated the safety and glycaemic effectiveness of linagliptin as monotherapy or combination therapy with other antidiabetic drugs in routine clinical practice. Endpoints were the incidence of adverse drug reactions (ADRs) and the change in HbA1c. Overall, 3119 and 2171 patients were included in the safety and effectiveness analysis sets, respectively. A total of 56 patients (1.8%) experienced ADRs. The most common ADR was gastrointestinal disorders (0.7%), followed by metabolism and nutrition disorders (0.5%). ADRs of special interest, including pancreatic diseases, cardiac diseases and hypoglycaemia, occurred in 12 patients, 11 of whom had hypoglycaemia, while one had a skin lesion. Mean HbA1c change during the study period was -0.8%. Lower body mass index, shorter diabetes duration and higher baseline HbA1c were independently associated with a better effectiveness, while the presence of diabetic complications, dyslipidaemia and the use of sulphonylureas were associated with a poor response. In conclusion, linagliptin showed an excellent safety profile and glycaemic effectiveness in Korean patients with T2D.

Long-term safety and effectiveness of linagliptin as add-on therapy in Japanese patients with type 2 diabetes: final results of a 3-year post-marketing surveillance

BACKGROUND

We investigated the long-term safety and effectiveness of linagliptin in Japanese type 2 diabetes (T2D) patients starting linagliptin add-on therapy in routine clinical practice.

RESEARCH DESIGN AND METHODS

This 3-year prospective, observational, post-marketing surveillance (PMS) was conducted in Japanese patients starting linagliptin add-on therapy. The primary outcome was the incidence of adverse drug reactions (ADRs). The secondary outcome was the change from baseline in HbA1c.

RESULTS

The safety analysis set comprised of 3,372 patients. Mean ± standard deviation (SD) age was 66.5 ± 12.4 years. Most patients (63.2%) received linagliptin in combination with another antidiabetic drug, most commonly a sulfonylurea (38.6%). The incidence of ADRs was 11.39%; the most common ADRs according to MedDRA preferred terms were diabetes mellitus (1.25%), hypertension (0.83%), and hypoglycemia (0.80%). In the effectiveness analysis set (n = 3,029), mean ± SD HbA1c was 7.76 ± 1.37% at baseline and 7.26 ± 1.19% at last observation; mean change from baseline to last observation was - 0.49 ± 1.33%; sustained reductions in HbA1c were observed. These results were consistent across patient subgroups.

CONCLUSIONS

In this PMS, linagliptin add-on therapy for Japanese T2D patients had a safety profile consistent with its known profile and HbA1c reductions over 3 years were observed.

CLINICALTRIALS.GOV

NCT01904383.

Long-Term Safety and Effectiveness of Linagliptin in Japanese Patients with Type 2 Diabetes Mellitus: A 3-Year Post-Marketing Surveillance Study

INTRODUCTION

Clinical trials of linagliptin in Japanese patients conducted to date have had limited observational periods; therefore, there is a need for additional longer-term real-world data. The aim of this study was to investigate the long-term safety and effectiveness of linagliptin in routine clinical practice.

METHODS

This was a prospective, observational, post-marketing surveillance study conducted over 156 weeks in patients with type 2 diabetes mellitus who started linagliptin monotherapy. The primary endpoint was the incidence of adverse drug reactions (ADRs). The secondary endpoint was the change in glycated hemoglobin (HbA1c) from baseline to last available observation. Other effectiveness endpoints included the change in HbA1c and change in fasting plasma glucose (FPG) from baseline to week 26 and over the course of the treatment period.

RESULTS

Overall, 2235 and 2054 patients were included in the safety and effectiveness analysis sets, respectively. Patients were mostly male (58.4%), and the mean age was 66.7 years. The incidence of ADRs was 10.7% (n = 240). The most frequent ADRs according to MedDRA preferred terms were diabetes mellitus (n = 35 patients, 1.6%), constipation (n = 21, 0.9%), diabetes mellitus inadequate control (n = 13, 0.6%) and hypertension (n = 13, 0.6%). The mean change in HbA1c from baseline to last observation was - 0.67% [standard deviation (SD) 1.27%, 95% confidence interval - 0.72, - 0.61]. At week 26, HbA1c and FPG showed mean ± SD changes from baseline of - 0.73 ± 1.20% and - 21.02 ± 44.33 mg/dL, respectively, that were sustained until week 156.

CONCLUSIONS

In Japanese patients with type 2 diabetes mellitus, linagliptin produced sustained reductions in HbA1c and had a safety profile consistent with the established safety profile of linagliptin.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01650259).

Linagliptin and cardiorenal outcomes in Asians with type 2 diabetes mellitus and established cardiovascular and/or kidney disease: subgroup analysis of the randomized CARMELINA® trial

Objective

Linagliptin, a dipeptidyl peptidase-4 inhibitor, demonstrated cardiovascular and renal safety in type 2 diabetes mellitus (T2DM) patients with established cardiovascular disease (CVD) with albuminuria and/or kidney disease in the multinational CARMELINA^® trial. We investigated the effects of linagliptin in Asian patients in CARMELINA^®.

Methods

T2DM patients with HbA1c 6.5-10.0% and established CVD with urinary albumin-to-creatinine ratio (UACR) > 30 mg/g, and/or prevalent kidney disease (estimated glomerular filtration rate [eGFR] 15-< 45 ml/min/1.73 m² or ≥ 45-75 with UACR > 200 mg/g), were randomized to linagliptin or placebo added to usual care. The primary endpoint was time to first occurrence of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke (3-point MACE).

Results

Of the 6979 patients, 555 (8.0%) were Asians living in Asia. During a median follow-up of 2.2 years, 3-point MACE occurred in 29/272 (10.7%) and 33/283 (11.7%) of linagliptin and placebo patients, respectively (hazard ratio [HR] 0.90; 95% confidence interval [CI] 0.55-1.48), consistent with the overall population (HR 1.02; 95% CI 0.89-1.17; P value for treatment-by-region interaction: 0.3349). Similar neutrality in Asian patients was seen for other cardiorenal events including the secondary kidney endpoint of death from renal failure, progression to end-stage kidney disease, or ≥ 40% eGFR decrease (HR 0.96; 95% CI 0.58-1.59). Linagliptin was associated with a nominal decrease in the risk of hospitalization for heart failure (HR 0.47; 95% CI 0.24-0.95). Overall in Asian patients, linagliptin had an adverse event rate similar to placebo, consistent with the overall population.

Conclusions

Linagliptin showed cardiovascular and renal safety in Asian patients with T2DM and established CVD with albuminuria and/or kidney disease.

Long-Term Efficacy and Safety of Linagliptin in a Japanese Population with Type 2 Diabetes Aged ≥ 60 Years Treated with Basal Insulin: A Randomised Trial

INTRODUCTION

An estimated 4.3 million people aged ≥ 65 years with diabetes live in Japan. We evaluated the efficacy and safety of linagliptin in older Japanese patients with poorly controlled type 2 diabetes (T2DM).

METHODS

In this phase 4, randomised, placebo-controlled national study (part of a global study) conducted in Japan over a period of 52 weeks, 102 patients on stable treatment with basal insulin ± metformin/alpha-glucosidase inhibitors were randomised (1:1) to receive linagliptin 5 mg qd or placebo. The primary end point was the change in glycated haemoglobin (HbA1c) after 24 weeks of treatment, with additional analyses at 52 weeks.

RESULTS

Mean age and HbA1c of the study population were 71 years and 8.1%, respectively. Approximately two-thirds of participants were aged ≥ 70 years, two-thirds had macrovascular complications, approximately half had a baseline estimated glomerular filtration rate < 60 ml/min/1.73 m², and two-thirds had a time since diagnosis of diabetes > 10 years. Significant HbA1c reductions with linagliptin vs. placebo were observed at 24 weeks, - 0.71% (95% CI - 0.96, - 0.45, p < 0.0001), and maintained at 52 weeks, - 0.58% (95% CI - 0.82, - 0.34, p < 0.0001). Linagliptin improved the chances of achieving a categorical HbA1c target (< 8.0% and < 7.0%) at 24 and 52 weeks in patients who were not at their respective target at the beginning of the study. Addition of linagliptin to insulin was associated with a numerical increase in the risk of any hypoglycaemia, but not in the risk of clinically significant hypoglycaemia, severe hypoglycaemia or recurring hypoglycaemia.

CONCLUSION

Linagliptin was effective in improving glucose control in Japanese patients aged ≥ 60 years with T2DM on stable glucose-lowering therapy with basal insulin. Linagliptin was well tolerated and no new safety concerns were raised. The results presented here are highly consistent with the results from the global study, which was conducted over a 24-week period.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02240680.

FUNDING

Boehringer Ingelheim and Eli Lilly and Company Diabetes Alliance.

Linagliptin safety profile: A systematic review

OBJECTIVE

To describe the safety profile of linagliptin.

METHODOLOGY

Systematic review using PubMed/MEDLINE, BVS and Web of Science. The search strategy "Linagliptin" AND "safety" was used. The inclusion criteria were clinical trials with a control group composed of conventional DM2 pharmacotherapy.

RESULTS

We identified 16 studies, and the most frequent adverse events (AEs) were nasopharyngitis with linagliptin at 5 and 10mg in monotherapy (31.6% and 29.6%, respectively) and gastrointestinal events (>10.0%) with linagliptin in combination. Of the AEs, 14.9 (±3.1)% were associated with the use of linagliptin in monotherapy, and 17.6 (±6.0)% in combination. The linagliptin AEs have a varied occurrence and frequency, ranging from mild to moderate intensity.

A randomized, placebo- and sitagliptin-controlled trial of the safety and efficacy of omarigliptin, a once-weekly dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes

AIMS

To assess the safety and efficacy of omarigliptin in Japanese patients with type 2 diabetes (T2D).

METHODS

In a 24-week double-blind trial, 414 patients with T2D were randomized to omarigliptin 25 mg once weekly, sitagliptin 50 mg once daily or placebo. The double-blind period was followed by a 28-week open-label extension during which all patients received omarigliptin 25 mg once weekly. Efficacy endpoints were glycated haemoglobin (HbA1c), 2-hour postprandial glucose (PPG) and fasting plasma glucose (FPG) levels.

RESULTS

After 24 weeks, the least squares (LS) mean change from baseline in HbA1c was -0.66% for omarigliptin, -0.65% for sitagliptin and 0.13% for placebo. The difference in LS mean for omarigliptin vs placebo was -0.80% ( P  < .001). The difference in LS mean for omarigliptin vs sitagliptin was -0.02% (95% confidence interval -0.15, 0.12), which met the criterion for non-inferiority to sitagliptin. Both active treatments provided significant reductions in FPG and 2-hour PPG compared with placebo (P < .001). Over the 24-week double-blind period, there were no clinically meaningful differences in the incidence rates of adverse events among the treatment groups. There was 1 episode of symptomatic hypoglycaemia in the sitagliptin group and none in the omarigliptin or placebo groups. In the 28-week open-label period, omarigliptin provided persistent improvements in glycaemic control without notable change in safety profile compared with the double-blind period. Omarigliptin had no meaningful effect on body weight.

CONCLUSIONS

In Japanese patients with T2D, omarigliptin 25 mg once weekly provided significant glucose-lowering compared with placebo and was non-inferior to sitagliptin 50 mg once daily. Omarigliptin was generally well tolerated for up to 52 weeks.

Oral glucose lowering with linagliptin and metformin compared with linagliptin alone as initial treatment in Asian patients with newly diagnosed type 2 diabetes and marked hyperglycemia: Subgroup analysis of a randomized clinical trial

AIMS/INTRODUCTION

Type 2 diabetes mellitus is an epidemic in Asia, yet clinical trials of glucose-lowering therapies often enroll predominantly Western populations. We explored the initial combination of metformin and linagliptin, a dipeptidyl peptidase-4 inhibitor, in newly diagnosed type 2 diabetes mellitus patients in Asia with marked hyperglycemia.

MATERIALS AND METHODS

This was a post-hoc subgroup analysis of a multinational, parallel-group clinical trial in which 316 newly diagnosed type 2 diabetes mellitus patients with glycated hemoglobin A1c (HbA1c) 8.5-12.0% were randomized to double-blind oral treatment with linagliptin/metformin or linagliptin monotherapy. The primary end-point was the change from baseline in HbA1c at week 24. We evaluated data for the 125 participants from Asian countries.

RESULTS

After 24 weeks, the mean ± standard error reduction from baseline in HbA1c (mean 10.0%) was -2.99 ± 0.18% with linagliptin/metformin and -1.84 ± 0.18% with linagliptin; a treatment difference of -1.15% (95% confidence interval -1.65 to -0.66, P < 0.0001). HbA1c <7.0% was achieved by 60% of participants receiving linagliptin/metformin. The mean bodyweight change after 24 weeks was -0.45 ± 0.41 kg and 1.33 ± 0.45 kg in the linagliptin/metformin and linagliptin groups, respectively (treatment difference -1.78 kg [95% confidence interval -2.99 to -0.57, P = 0.0043]). Drug-related adverse events occurred in 9.7% of participants receiving linagliptin/metformin and 4.8% of those receiving linagliptin. Hypoglycemia occurred in 6.5% and 4.8% of the linagliptin/metformin and linagliptin groups, respectively, with no severe episodes. Gastrointestinal disorders occurred in 12.9% and 12.7% of the linagliptin/metformin and linagliptin groups, respectively, with no associated treatment discontinuations.

CONCLUSIONS

In people from Asia with newly diagnosed type 2 diabetes mellitus and marked hyperglycemia, the initial combination of linagliptin and metformin substantially improved glycemic control without weight gain and with infrequent hypoglycemia. Initial oral combination therapy might be a viable treatment for such individuals.

A Randomized, Placebo-Controlled Trial Evaluating the Safety and Efficacy of Adding Omarigliptin to Antihyperglycemic Therapies in Japanese Patients with Type 2 Diabetes and Inadequate Glycemic Control

INTRODUCTION

Daily dipeptidyl peptidase-4 (DPP-4) inhibitors are commonly used with other orally administered antihyperglycemic agents (AHA), as combination therapy, to treat Japanese patients with type 2 diabetes. When combination therapy is indicated, use of a once-weekly (q.w.) orally administered DPP-4 inhibitor might be an appropriate therapeutic option for some patients.

METHODS

A 52-week trial was conducted to assess the safety and tolerability (primary objectives) and glycemic efficacy (secondary objectives) of the q.w. DPP-4 inhibitor omarigliptin as add-on therapy to five different classes of orally administered AHA [sulfonylurea (SU), glinide (GL), biguanide (BG), thiazolidinedione (TZD), or α-glucosidase inhibitor (AGI)] commonly used in Japan and having different mechanisms of drug action from DPP-4 inhibitors. The trial consisted of an initial 24-week double-blind, placebo-controlled period during which patients (stratified by background AHA) were randomized to omarigliptin 25 mg q.w. or placebo, followed by a 28-week open-label period during which patients on placebo were switched to omarigliptin.

RESULTS

After 24 weeks, the percentages of patients with adverse events (AEs), serious AEs, drug-related AEs, AEs of symptomatic hypoglycemia, or who discontinued from trial medication because of an AE were generally similar in the omarigliptin and placebo groups, in all background AHA strata and in the overall population. From a mean baseline HbA1c of approximately 8.0%, the placebo-adjusted least-squares mean changes from baseline ranged from -0.80% (AGI stratum) to -1.16% (TZD stratum); p < 0.001 for all background AHA strata. During the open-label period, no safety signals emerged with longer-term treatment. At week 52, the change from baseline in HbA1c in the omarigliptin/omarigliptin group was similar to that of the placebo/omarigliptin group.

CONCLUSIONS

Addition of once-weekly omarigliptin to AHA therapy with an SU, GL, BG, TZD, or AGI for up to 52 weeks was generally safe and well tolerated, and provided persistent efficacy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT01697592.

FUNDING

MSD K.K., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.

Adverse effects of incretin-based therapies on major cardiovascular and arrhythmia events: meta-analysis of randomized trials

BACKGROUND

Recent cardiovascular outcome trials of incretin-based therapies (IBT) in type 2 diabetes have not demonstrated either benefit or harm in terms of major adverse cardiovascular events (MACE). Earlier meta-analyses showed conflicting results but were limited in methodology. We aimed to perform an updated meta-analysis of all available incretin therapies on the incidence of MACE plus arrhythmia and heart failure.

METHODS

We identified studies published through November 2014 by searching electronic databases and reference lists. We included RCTs in which the intervention group received incretin-based therapies and the control group received placebo or standard treatment; enrolled >100 participants in each group; interventions lasted >24 weeks; and reported data on one or more primary major adverse cardiovascular events endpoints plus terms for arrhythmia and heart failure. We used the Peto method for each CV event for individual IBT treatment.

RESULTS

In this meta-analysis of 100 RCTs involving 54,758 incretin-based therapies users and 48,175 controls, exenatide was associated with increased risk of arrhythmia (OR 2.83; 95% CI, 1.06-7.57); saxagliptin was associated with an increased risk of heart failure (OR 1.23; 95% CI, 1.03-1.46), and sitagliptin was associated with a significantly decreased risk of all cause death compared to active controls (OR 0.39, 95% CI 0.18-0.82).

CONCLUSIONS

In type 2 diabetes, exenatide may increase the risk of arrhythmia, and sitagliptin may reduce the risk of all cause death; however, the subgroup of patients most likely to experience harm or benefit is unclear. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of linagliptin monotherapy compared with voglibose on postprandial blood glucose responses in Japanese patients with type 2 diabetes: Linagliptin Study of Effects on Postprandial blood glucose (L-STEP)

AIMS

To compare the efficacy on glycemic parameters between a 12-week administration of once-daily linagliptin and thrice-daily voglibose in Japanese patients with type 2 diabetes.

METHODS

In a multi-center, randomized, parallel-group study, 382 patients with diabetes were randomized to the linagliptin group (n=192) or the voglibose group (n=190). A meal tolerance test was performed at weeks 0 and 12. Primary outcomes were the change from baseline to week 12 in serum glucose levels at 2h during the meal tolerance test, HbA1c levels, and serum fasting glucose levels, which were compared between the 2 groups.

RESULTS

Whereas changes in serum glucose levels at 2h during the meal tolerance test did not differ between the groups, the mean change in HbA1c levels from baseline to week 12 in the linagliptin group (-0.5±0.5% [-5.1±5.4mmol/mol]) was significantly larger than in the voglibose group (-0.2±0.5% [-2.7±5.4mmol/mol]). In addition, there was significant difference in changes in serum fasting glucose levels (-0.51±0.95mmol/L in the linagliptin group vs. -0.18±0.92mmol/L in the voglibose group, P<0.001). The incidences of hypoglycemia, serious adverse events (AEs), and discontinuations due to AEs were low and similar in both groups. However, gastrointestinal AEs were significantly lower in the linagliptin group (1.05% vs. 5.85%; P=0.01).

CONCLUSIONS

These data suggested that linagliptin monotherapy had a stronger glucose-lowering effect than voglibose monotherapy with respect to HbA1c and serum fasting glucose levels, but not serum glucose levels 2h after the start of the meal tolerance test.

The clinical application of linagliptin in Asians

Asia has a growing diabetic population. Linagliptin, a member of dipeptidyl peptidase-4 inhibitor class, is unique in its nonlinear pharmacokinetics with the characteristics of rapid attainment of steady state, little accumulation, predominantly nonrenal route of elimination, prolonged terminal half-life, and sustained inhibition of dipeptidyl peptidase-4 enzyme. No clinically relevant difference in pharmacokinetics was observed between Asians and non-Asians. The management of type 2 diabetes is increasingly challenging with the progression of disease, especially with the requirements of minimal hypoglycemia, weight gain, fluid retention, and other adverse effects. Linagliptin was efficacious and well-tolerated in Asian type 2 diabetes patients with or without renal or hepatic dysfunctions, comparable to that in Caucasians. This review will focus on the usage of linagliptin in clinical studies in Asians.

Incretins and selective renal sodium-glucose co-transporter 2 inhibitors in hypertension and coronary heart disease

Hyperglycemia is associated with an increased risk of cardiovascular disease, and the consequences of intensive therapy may depend on the mechanism of the anti-diabetic agent(s) used to achieve a tight control. In animal models, stable analogues of glucagon-like peptide-1 (GLP-1) were able to reduce body weight and blood pressure and also had favorable effects on ischemia following coronary reperfusion. In a similar way, dipeptidyl peptidase IV (DPP-IV) showed to have favorable effects in animal models of ischemia/reperfusion. This could be due to the fact that DPP-IV inhibitors were able to prevent the breakdown of GLP-1 and glucose-dependent insulinotropic polypeptide, but they also decreased the degradation of several vasoactive peptides. Preclinical data for GLP-1, its derivatives and inhibitors of the DPP-IV enzyme degradation suggests that these agents may be able to, besides controlling glycaemia, induce cardio-protective and vasodilator effects. Notwithstanding the many favorable cardiovascular effects of GLP-1/incretins reported in different studies, many questions remain unanswered due the limited number of studies in human beings that aim to examine the effects of GLP-1 on cardiovascular endpoints. For this reason, long-term trials searching for positive cardiovascular effects are now in process, such as the CAROLINA and CARMELINA trials, which are supported by small pilot studies performed in humans (and many more animal studies) with incretin-based therapies. On the other hand, selective renal sodium-glucose co-transporter 2 inhibitors were also evaluated in the prevention of cardiovascular outcomes in type 2 diabetes. However, it is quite early to draw conclusions, since data on cardiovascular outcomes and cardiovascular death are limited and long-term studies are still ongoing. In this review, we will analyze the mechanisms underlying the cardiovascular effects of incretins and, at the same time, we will present a critical position about the real value of these compounds in the cardiovascular system and its protection.

Racial/ethnic disparities in prevalence and care of patients with type 2 diabetes mellitus

BACKGROUND

As of 2012, nearly 10% of Americans had diabetes mellitus. People with diabetes are at approximately double the risk of premature death compared with those in the same age groups without the condition. While the prevalence of diabetes has risen across all racial/ethnic groups over the past 30 years, rates are higher in minority populations. The objective of this review article is to evaluate the prevalence of diabetes and disease-related comorbidities as well as the primary endpoints of clinical studies assessing glucose-lowering treatments in African Americans, Hispanics, and Asians.

METHODS

As part of our examination of this topic, we reviewed epidemiologic and outcome publications. Additionally, we performed a comprehensive literature search of clinical trials that evaluated glucose-lowering drugs in racial minority populations. For race/ethnicity, we used the terms African American, African, Hispanic, and Asian. We searched PubMed for clinical trial results from 1996 to 2015 using these terms by drug class and specific drug. Search results were filtered qualitatively.

RESULTS

Overall, the majority of publications that fit our search criteria pertained to native Asian patient populations (i.e., Asian patients in Asian countries). Sulfonylureas; the α-glucosidase inhibitor, miglitol; the biguanide, metformin; and the thiazolidinedione, rosiglitazone have been evaluated in African American and Hispanic populations, as well as in Asians. The literature on other glucose-lowering drugs in non-white races/ethnicities is more limited.

CONCLUSIONS

Clinical data are needed for guiding diabetes treatment among racial minority populations. A multi-faceted approach, including vigilant screening in at-risk populations, aggressive treatment, and culturally sensitive patient education, could help reduce the burden of diabetes on minority populations. To ensure optimal outcomes, educational programs that integrate culturally relevant approaches should highlight the importance of risk-factor control in minority patients.

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.

The efficacy of vildagliptin concomitant with insulin therapy in type 2 diabetic subjects

BACKGROUND

In Japan, dipeptidyl peptidase 4 (DPP4) inhibitors have become standard therapeutic agents for type 2 diabetes, and numbers of patients receiving insulin therapy combined with DPP4 inhibitors, which is a highly effective regimen, are increasing.

METHODS

In this study, we evaluated the efficacy of vildagliptin administered at the dose of 100 mg twice daily in 57 patients with type 2 diabetes already receiving insulin treatment.

RESULTS

The 36 patients who simply received add-on vildagliptin showed a 0.6% decrease in HbA1c levels, despite a marked insulin dose reduction, mainly bolus insulin, of approximately 8.3 units. In addition, body mass index exhibited a significant negative correlation with the efficacy of vildagliptin, i.e., ΔHbA1c. On the other hand, the 21 patients switched from 50 mg of sitagliptin to vildagliptin showed HbA1c decreases approaching 0.7%.

CONCLUSION

Taking into consideration that twice-daily oral vildagliptin has already been reported to be advantageous in reducing postprandial hyperglycemia, this drug was suggested to be more effective in reducing HbA1c than sitagliptin under conditions in which it is used as a supplement to basal insulin, as in this study.

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.

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

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

Incretin treatment and risk of pancreatitis in patients with type 2 diabetes mellitus: systematic review and meta-analysis of randomised and non-randomised studies

OBJECTIVE

To investigate the risk of pancreatitis associated with the use of incretin-based treatments in patients with type 2 diabetes mellitus.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov.

ELIGIBILITY CRITERIA

Randomised and non-randomised controlled clinical trials, prospective or retrospective cohort studies, and case-control studies of treatment with glucagon-like peptide-1 (GLP-1) receptor agonists or dipeptidyl peptidase-4 (DPP-4) inhibitors in adults with type 2 diabetes mellitus compared with placebo, lifestyle modification, or active anti-diabetic drugs.

DATA COLLECTION AND ANALYSIS

Pairs of trained reviewers independently screened for eligible studies, assessed risk of bias, and extracted data. A modified Cochrane tool for randomised controlled trials and a modified version of the Newcastle-Ottawa scale for observational studies were used to assess bias. We pooled data from randomised controlled trials using Peto odds ratios, and conducted four prespecified subgroup analyses and a post hoc subgroup analysis. Because of variation in outcome measures and forms of data, we describe the results of observational studies without a pooled analysis.

RESULTS

60 studies (n=353,639), consisting of 55 randomised controlled trials (n=33,350) and five observational studies (three retrospective cohort studies, and two case-control studies; n=320,289) were included. Pooled estimates of 55 randomised controlled trials (at low or moderate risk of bias involving 37 pancreatitis events, raw event rate 0.11%) did not suggest an increased risk of pancreatitis with incretins versus control (odds ratio 1.11, 95% confidence interval 0.57 to 2.17). Estimates by type of incretin suggested similar results (1.05 (0.37 to 2.94) for GLP-1 agonists v control; 1.06 (0.46 to 2.45) for DPP-4 inhibitors v control). Analyses according to the type of control, mode, duration of treatment, and individual incretin agents suggested no differential effect by subgroups, and sensitivity analyses by alternative statistical modelling and effect measures did not show important differences in effect estimates. Three retrospective cohort studies (moderate to high risk of bias, involving 1466 pancreatitis events, raw event rate 0.47%) also did not suggest an increased risk of pancreatitis associated with either exenatide (adjusted odds ratios 0.93 (0.63 to 1.36) in one study and 0.9 (0.6 to 1.5) in another) or sitagliptin (adjusted hazard ratio 1.0, 0.7 to 1.3); a case-control study at moderate risk of bias (1003 cases, 4012 controls) also suggested no significant association (adjusted odds ratio 0.98, 0.69 to 1.38). Another case-control study (1269 cases, 1269 controls) at moderate risk of bias, however, suggested that the use of either exenatide or sitagliptin was associated with significantly increased odds of acute pancreatitis (use within two years v no use, adjusted odds ratio 2.07, 1.36 to 3.13).

CONCLUSIONS

The available evidence suggests that the incidence of pancreatitis among patients using incretins is low and that the drugs do not increase the risk of pancreatitis. Current evidence, however, is not definitive, and more carefully designed and conducted observational studies are warranted to definitively establish the extent, if any, of increased risk.