Efficacy and safety of initial combination treatment with sitagliptin and pioglitazone--a factorial study

Initial Combination Therapy in Type 2 Diabetes

Type 2 diabetes (T2D) is a progressive disease in which it is challenging to achieve long-term durable glycemic control. However, intensive glycemic control is crucial for preventing diabetes-related complications. Previous studies showed that monotherapy with a stepwise add-on approach was seldom effective for long-term durable glycemic control. Combination therapy, which refers to the use of two or more drugs to control hyperglycemia, has multiple benefits, including the ability to target a variety of pathophysiological processes underlying hyperglycemia. In clinical trials, initial combination therapy showed better glycemic control than monotherapy or a stepwise approach. Emerging evidence indicates that initial combination therapy is associated with preserved β-cell function and fewer complications in T2D. However, cost-effectiveness and adverse events with combination therapy are issues that should be considered. Therefore, initial combination therapy is an important option for patients with T2D that clinicians should consider with a view toward balancing benefits and potential harms. In this review, we summarize the literature addressing initial combination therapy in T2D, and we suggest optimal strategies based on clinical situations and patient characteristics.

Dipeptidyl peptidase-4 inhibitors and gallbladder or biliary disease in type 2 diabetes: systematic review and pairwise and network meta-analysis of randomised controlled trials

OBJECTIVE

To examine the association between dipeptidyl peptidase-4 inhibitors and gallbladder or biliary diseases.

DESIGN

Systematic review and pairwise and network meta-analysis.

DATA SOURCES

PubMed, EMBASE, Web of Science, and CENTRAL from inception until 31 July 2021.

ELIGIBILITY CRITERIA

Randomised controlled trials of adult patients with type 2 diabetes who received dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors compared with placebo or other antidiabetes drugs.

MAIN OUTCOME MEASURES

Composite of gallbladder or biliary diseases, cholecystitis, cholelithiasis, and biliary diseases.

DATA EXTRACTION AND DATA SYNTHESIS

Two reviewers independently extracted the data and assessed the quality of the studies. The quality of the evidence for each outcome was assessed using the Grading of Recommendations, Assessment, Development and Evaluations framework (GRADE) approach. The meta-analysis used pooled odds ratios and 95% confidence intervals.

RESULTS

A total of 82 randomised controlled trials with 104 833 participants were included in the pairwise meta-analysis. Compared with placebo or non-incretin drugs, dipeptidyl peptidase-4 inhibitors were significantly associated with an increased risk of the composite of gallbladder or biliary diseases (odds ratio 1.22 (95%confidence interval 1.04 to 1.43); risk difference 11 (2 to 21) more events per 10 000 person years) and cholecystitis (odds ratio 1.43 (1.14 to 1.79); risk difference 15 (5 to 27) more events per 10 000 person years) but not with the risk of cholelithiasis and biliary diseases. The associations tended to be observed in patients with a longer duration of dipeptidyl peptidase-4 inhibitor treatment. In the network meta-analysis of 184 trials, dipeptidyl peptidase-4 inhibitors increased the risk of the composite of gallbladder or biliary diseases and cholecystitis compared with sodium-glucose cotransporter-2 inhibitors but not compared with glucagon-like peptide-1 receptor agonists.

CONCLUSIONS

Dipeptidyl peptidase-4 inhibitors increased the risk of cholecystitis in randomised controlled trials, especially with a longer treatment duration, which requires more attention from physicians in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021271647.

Effects of pioglitazone on cardiovascular events and all-cause mortality in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

AIM

In 2019, the Italian Society of Diabetology and the Italian Association of Clinical Diabetologists nominated an expert panel to develop guidelines for drug treatment of type 2 diabetes. After identifying the effects of glucose-lowering agents on major adverse cardiovascular events (MACEs), all-cause mortality, and hospitalization for heart failure (HHF) as critical outcomes, the experts decided to perform a systematic review and meta-analysis on the effect of pioglitazone with this respect.

DATA SYNTHESIS

A MEDLINE database search was performed to identify RCTs, up to June 1st, 2021, with duration≥52 weeks, in which pioglitazone was compared with either placebo or active comparators. The principal endpoints were MACE and HHF (restricted for RCT reporting MACEs within their outcomes), all-cause mortality (irrespective of the inclusion of MACEs among the pre-specified outcomes). Mantel-Haenszel odds ratio (MH-OR) with 95% Confidence Interval (95% CI) was calculated for all the endpoints considered. Eight RCTs were included in the analysis for MACEs and HF (5048 and 5117 patients in the pioglitazone and control group, respectively), and 24 in that for all-cause mortality (10,682 and 9674 patients). Pioglitazone neither significantly increased nor reduced the risk of MACE, all-cause mortality, and HHF in comparison with placebo/active comparators (MH-OR: 0.90, 95% CI 0.78-1.03, 0.91, 95% CI 0.77, 1.09, and 1.16, 95% CI 0.73, 1.83, respectively). Pioglitazone was associated with a significant reduction of MACE in patients with prior cardiovascular events (MH-OR 0.84, 95% CI 0.72-0.99).

CONCLUSIONS

This meta-analysis showed no significant effects of pioglitazone on incident MACE, all-cause mortality, and HHF.

Comparisons between dipeptidyl peptidase-4 inhibitors and other classes of hypoglycemic drugs using two distinct biomarkers of pancreatic beta-cell function: A meta-analysis

Background and objective

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been suggested to have pancreatic beta-cell preserving effect according to studies using homeostatic model of assessment for beta-cell function (HOMA-β). However, whether HOMA-β is a suitable biomarker for comparisons between hypoglycemic drugs with different mechanisms of action remains unclear. Therefore, we conducted a meta-analysis to compare the effects of DPP-4 inhibitors and other classes of hypoglycemic drugs on HOMA-β and proinsulin-to-insulin ratio (PIR).

Methods

We searched MEDLINE, CENTRAL, and Ichushi-web for the period of 1966 to May 2020. We collected randomized, controlled clinical trials in patients with type 2 diabetes mellitus comparing DPP-4 inhibitors and other classes of hypoglycemic agents [α-glucosidase inhibitors (α-GIs), glucagon-like peptide-1 (GLP-1) analogues, metformin, sodium-glucose cotransporter 2 (SGLT2) inhibitors, sulfonylureas, or thiazolidinediones]. Weighted mean differences and 95% confidence intervals of changes in HOMA-β or PIR during study periods were calculated for pairwise comparisons.

Results

Thirty-seven and 21 relevant trials were retrieved for comparisons of HOMA-β and PIR, respectively. HOMA-β and PIR consistently showed superiority of DPP-4 inhibitors compared with α-GIs. Both biomarkers consistently supported inferiority of DPP-4 inhibitors compared with GLP-1 analogues. However, PIR showed inferiority of DPP-4 inhibitors compared with metformin, and superiority compared with SGLT2 inhibitors, whereas HOMA-β showed no significant differences between DPP-4 inhibitors and the two other agents.

Conclusion

DPP-4 inhibitors appear to be superior to α-GIs but inferior to GLP-1 analogues in preservation of beta-cell function assessed by either HOMA-β or PIR. DPP-4 inhibitors seem to be superior to SGLT2 inhibitors but inferior to metformin on islet function assessed only by PIR. Because HOMA-β and PIR may indicate different aspects of beta-cell function, results of beta-cell function preserving effects of hypoglycemic agents should be interpreted with caution.

An Assessment of Pharmacokinetic Interaction Between Lobeglitazone and Sitagliptin After Multiple Oral Administrations in Healthy Men

PURPOSE

Patients with type 2 diabetes mellitus require strict blood glucose control, and combination therapy with a thiazolidinedione and dipeptidyl peptidase-4 inhibitors, such as lobeglitazone and sitagliptin, is one of the recommended treatments. The objective of this study was to investigate a possible pharmacokinetic interaction between lobeglitazone and sitagliptin after multiple oral administrations in healthy Korean men.

METHODS

Two randomized, open-label, multiple-dose, 2-way crossover studies were conducted simultaneously in healthy men. In study 1, men were randomly assigned to 1 of 2 sequences, and 1 of the following treatments was administered in each period: 1 tablet of lobeglitazone sulfate (0.5 mg) once daily for 5 days and or 1 tablet each of lobeglitazone sulfate (0.5 mg) and sitagliptin (100 mg) once daily for 5 days. In study 2, men were also randomly assigned to 1 of 2 sequences and the treatments were as follows: 1 tablet of sitagliptin (100 mg) once daily for 5 days or 1 tablet each of sitagliptin (100 mg) and lobeglitazone sulfate (0.5 mg) once daily for 5 days. Serial blood samples were collected up to 48 h after dosing on the fifth day. Plasma drug concentrations were measured by LC-MS/MS. Pharmacokinetic parameters, including C_max,ss and AUC_0-τ , were determined by noncompartmental analysis. The geometric least-square mean (GLSM) ratios and associated 90% CIs of log-transformed C_max,ss and AUC_0-τ for separate or coadministration were calculated to evaluate pharmacokinetic interactions.

FINDINGS

Nineteen men from study 1 and 17 from study 2 completed the pharmacokinetic sampling and were included in the analyses. The GLSM ratios of C_max,ss and AUC_0-τ were 0.9494 (95% CI, 0.8798-1.0243) and 1.0106 (95% CI, 0.9119-1.1198) for lobeglitazone (from study 1) and 1.1694 (95% CI, 1.0740-1.2732) and 1.0037 (95% CI, 0.9715-1.0369) for sitagliptin (from study 2), respectively.

IMPLICATIONS

Except for the slight 17% increase in the sitagliptin C_max,ss value, the pharmacokinetic parameters of lobeglitazone and sitagliptin met the pharmacokinetic equivalent criteria when administered separately or in combination. The increase in C_max of sitagliptin when coadministered with lobeglitazone would not be clinically significant in practice. ClinicalTrials.gov Identifier: NCT02824874 and NCT02827890.

Cardiovascular risk of sitagliptin in treating patients with type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (T2DM) have a very high risk of cardiovascular related events, and reducing complications is an important evaluation criterion of efficacy and safety of hypoglycemic drugs. Previous studies have shown that the dipeptidyl peptidase-4 (DPP-4) inhibitors (DPP4i), such as sitagliptin, might reduce the incidence of major cardiovascular events (MACEs). However, the safety and efficacy of sitagliptin remains controversial, especially the safety for cardiovascular related events. Here, a systematic review was conducted to assess the cardiovascular safety of sitagliptin in T2DM patients. The literature research dating up to October 2018 was performed in the electronic database. The clinical trials about sitagliptin for T2DM patients were included. Two reviewers independently screened literature according to the inclusion and exclusion criteria. The primary outcome was the MACE, and the secondary outcome was all-cause mortality. Finally, 32 clinical trials composed of 16082 T2DM patients were included in this meta-analysis. The results showed that: there was no significant difference between sitagliptin group and the control group on MACE (odds ratio (OR) = 0.85, 95% confidence intervals (CIs) = 0.63–1.15), myocardial infarction (MI) (OR = 0.66, 95% CI = 0.38–1.16), stroke (OR = 0.83, 95% CI = 0.44–1.54) and mortality (OR = 0.52, 95% CI = 0.26–1.07). These results demonstrated that sitagliptin did not increase the risk of cardiovascular events in patients with T2DM.

Comparison of dipeptidyl peptidase-4 inhibitors and pioglitazone combination therapy versus pioglitazone monotherapy in type 2 diabetes: A system review and meta-analysis

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitor and pioglitazone combination therapy have been widely used for patients with inadequate glycemic control on monotherapy. This meta-analysis assessed the efficacy and safety of this combination therapy in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched the MEDLINE, Embase, and Cochrane databases. Studies were eligible if they were randomized controlled trials (RCTs) on DPP-4 inhibitor and pioglitazone combination therapy in patients with T2DM through the end of February 2016, using the keywords "alogliptin," "dutogliptin, " "linagliptin," "saxagliptin," "sitagliptin," "vildagliptin," "gliptins," "DPP-4 inhibitor," and "pioglitazone." RCTs were selected if they compared DPP-4 inhibitors and pioglitazone as combination therapy; treatment duration was ≥12 weeks; and the reported data included hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG) change, total or any other system Adverse Events (AEs). We estimated effect size with random-effects or fixed-effects meta-analysis, I statistic was used to estimate heterogeneity of results.

RESULTS

Seven RCTs were included. Compared with pioglitazone monotherapy, combination DPP-4 inhibitor and pioglitazone therapy were associated with increased reduction in HbA1c ([MD]-0.64%;-0.73 to -0.55) and FPG ([MD] -0.94; -1.12 to -0.76) levels, more patients in the combination therapy groups versus pioglitazone monotherapy groups had an A1c of < 7% ([OR]2.52; 2.18, 3.17) at the end of the studies, but was not associated with further reduction in higher risk of hypoglycaemia, edema, or any other system AEs. We also noticed that DPP-4 inhibitor and pioglitazone combination therapy were associated with better improvement of pancreatic β-cell function.

CONCLUSIONS

DPP-4 inhibitor and pioglitazone combination therapy provided better glycemic control, both according to HbA1c and FPG levels, than pioglitazone monotherapy. Safety analysis showed well tolerance of combination therapy, even in hypoglycemic and edema AEs. However, additional large-scale, high quality, long-term follow-up clinical trials are necessary to confirm its long-term effectiveness.

Differential effect of concomitant antidiabetic agents on carotid atherosclerosis: a subgroup analysis of the PROLOGUE study

Accumulated evidence shows that some antidiabetic agents attenuate the progression of carotid atherosclerosis assessed as intima-media thickness (IMT). Although some studies have demonstrated an inhibitory effect of dipeptidyl peptidase-4 inhibitors on carotid IMT progression, in the PROLOGUE study sitagliptin failed to slow progression relative to conventional therapy for 24 months. We hypothesized that differences in the concomitant antidiabetic agents between the groups have influenced the progression of carotid IMT. We performed a post hoc analysis of the PROLOGUE study using subgroups stratified by concomitant antidiabetic agents. Although no subgroup with any combination of agents in the overall patients showed a significant difference between sitagliptin group and conventional therapy group in the changes from baseline in mean common carotid artery (CCA)-IMT at 24 months, a significant attenuation of mean CCA-IMT progression was observed in the sitagliptin group relative to conventional therapy group only in three combination subgroups aged < 70 years, namely no thiazolidinedione; no thiazolidinedione or biguanide; and no thiazolidinedione, biguanide or α-glucosidase inhibitor, even after adjustment for multiple confounding factors. In the three subgroups, no significant difference between sitagliptin group and conventional therapy group in the changes from baseline in HbA1c at 24 months was detected. Our data suggest that some concomitant agents, whose prescription frequencies were increased in the conventional therapy group, may have masked the inhibitory effect of sitagliptin on carotid IMT progression in the PROLOGUE study.

Efficacy and Safety of Initial Combination Therapy in Treatment-Naïve Type 2 Diabetes Patients: A Systematic Review and Meta-analysis

INTRODUCTION

The aim of this study was to evaluate the efficacy and safety of initial combination therapy compared with monotherapy in drug-naïve type 2 diabetes patients.

METHODS

MEDLINE, Embase and the Cochrane Central Register of Controlled Trials were searched for randomized clinical trials of initial combination therapy with hypoglycemic agents compared with monotherapy. Those which satisfied the search criteria were included in the meta-analysis. Weighted mean difference and relative risks were calculated.

RESULTS

A total of 36 studies were included in the meta-analysis. Compared with metformin monotherapy, initial combination therapy with metformin plus another anti-diabetes drug exhibited significant reductions in glycated hemoglobin (HbA1c) (p < 0.001). Most of the combination therapies had a similar risk of hypoglycemia (p > 0.05), with the exception of combinations of sulfonylurea/glinide and metformin or combinations of thiazolidinedione and metformin. Compared with dipeptidyl peptidase-4 (DPP-4) inhibitor monotherapy, initial combination therapy with DPP-4 inhibitor plus another anti-diabetes drug showed a significant decrease in HbA1c (p < 0.001) and a similar risk of hypoglycemia (p > 0.05). Compared with monotherapy with other anti-diabetes drugs, initial combination therapies also resulted in significant HbA1c reductions, a similar risk of hypoglycemia and similar risks of other adverse events.

CONCLUSION

Compared with monotherapy, all initial combination therapies resulted in significant HbA1c reductions. Compared with metformin monotherapy, initial combination therapies with DPP-4 inhibitors plus metformin, sodium/glucose cotransporter 2 inhibitors and metformin, respectively, were associated with similar risks of hypoglycemia, but initial combination therapies with sulfonylurea plus metformin, thiazolidinedione and metformin, respectively, were associated with higher risks of hypoglycemia.

FUNDING

AstraZeneca Ltd. (China).

TRIAL REGISTRATION

Registration number CRD42017060717 in PROSPERO.

Incretin-based therapies and risk of pancreatic cancer in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

AIMS

To perform a meta-analysis of randomized controlled trials (RCTs), including 6 recently published large-scale cardiovascular outcome trials (CVOTs), to evaluate the risk of pancreatic cancer with incretin-based therapies in patients with type 2 diabetes (T2DM).

MATERIALS AND METHODS

For the period January 1, 2007 to May 1, 2017, the PubMed, Embase, Cochrane Central Register and ClininalTrials.gov databases were searched for RCTs in people with T2DM that compared incretin drugs with placebo or other antidiabetic drugs, with treatment and follow-up durations of ≥52 weeks. Two reviewers screened the studies, extracted the data and assessed the risk of bias independently and in duplicate.

RESULTS

A total of 33 studies (n = 79 971), including the 6 CVOTs, with 87 pancreatic cancer events were identified. Overall, the pancreatic cancer risk was not increased in patients administered incretin drugs compared with controls (Peto odds ratio [OR] 0.67, 95% confidence interval [CI] 0.44-1.02). In the 6 CVOTs, 79 pancreatic cancer events were identified in 55 248 participants. Pooled estimates of the 6 CVOTs showed an identical tendency (Peto OR 0.65, 95% CI 0.42-1.01). Notably, in the subgroup of participants who received treatment and follow-up for ≥104 weeks, 84 pancreatic cancer events were identified in 59 919 participants, and a lower risk of pancreatic cancer was associated with incretin-based therapies (Peto OR 0.62, 95% CI 0.41-0.95).

CONCLUSIONS

Treatment with incretin drugs was not associated with an increased risk of pancreatic cancer in people with T2DM. Instead, it might protect against pancreatic malignancy in patients treated for ≥104 weeks.

Practical strategies for improving outcomes in T2DM: The potential role of pioglitazone and DPP4 inhibitors

T2DM is a complex disease underlined by multiple pathogenic defects responsible for the development and progression of hyperglycaemia. Each of these factors can now be tackled in a more targeted manner thanks to glucose-lowering drugs that have been made available in the past 2 to 3 decades. Recognition of the multiplicity of the mechanisms underlying hyperglycaemia calls for treatments that address more than 1 of these mechanisms, with more emphasis placed on the earlier use of combination therapies. Although chronic hyperglycaemia contributes to and amplifies cardiovascular risk, several trials have failed to show a marked effect from intensive glycaemic control. During the past 10 years, the effect of specific glucose-lowering agents on cardiovascular risk has been explored with dedicated trials. Overall, the cardiovascular safety of the new glucose-lowering agents has been proven with some of the trials summarized in this review, showing significant reduction of cardiovascular risk. Against this background, pioglitazone, in addition to exerting a sustained glucose-lowering effect, also has ancillary metabolic actions of potential interest in addressing the cardiovascular risk of T2DM, such as preservation of beta-cell mass and function. As such, it seems a logical agent to combine with other oral anti-hyperglycaemic agents, including dipeptidyl peptidase-4 inhibitors (DPP4i). DPP4i, which may also have a potential to preserve beta-cell function, is available as a fixed-dose combination with pioglitazone, and could, potentially, attenuate some of the side effects of pioglitazone, particularly if a lower dose of the thiazolidinedione is used. This review critically discusses the potential for early combination of pioglitazone and DPP4i.

Intensifying Treatment Beyond Monotherapy in Type 2 Diabetes Mellitus: Where Do Newer Therapies Fit?

PURPOSE OF REVIEW

Guidelines for a standard second diabetes medication for the treatment of type 2 diabetes (T2DM) have yet to be established. The rapid increase in the number of newer therapies available makes the choice more difficult. Thus, we reviewed clinical trial evidence evaluating newer therapies available for treatment intensification beyond monotherapy.

RECENT FINDINGS

Head-to-head studies comparing newer therapies versus traditional (i.e., sulfonylurea) approaches consistently find lower incidence of hypoglycemia and weight gain with newer therapies. Glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose co-transporter 2 (SGLT2) inhibitors demonstrate high glycemic efficacy, while merits of dipeptidyl peptidase-4 (DPP-4) inhibitors include their tolerability. Secondary effects (weight loss, cardiovascular outcomes, renal function) are of growing interest with newer therapies. Choices for treatment intensification in T2DM diabetes are numerous. Understanding the comparative evidence of newer treatment choices, as provided in this review, may help guide clinical decision making.

Dipeptidyl peptidase-4 inhibitors and the risk of heart failure: a systematic review and meta-analysis

BACKGROUND

Given recent discrepant results from randomized controlled trials (RCTs), we examined the totality of RCT evidence assessing the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and heart failure.

METHODS

MEDLINE, Embase and ClinicalTrials.gov were searched without language restrictions to August 2016 for RCTs comparing DPP-4 inhibitors to placebo or no therapy for a period of 24 weeks or more. We included all heart failure outcomes when listed either as a serious adverse event or adverse event. Pooled analyses used random-effects.

RESULTS

We identified 100 RCTs (n = 79 867) - 3 large cardiovascular-safety RCTs (SAVOR-TIMI 53[saxagliptin]/n = 16 492, EXAMINE[alogliptin]/n = 5380, and TECOS[sitagliptin]/n = 14 735), and 97 smaller RCTs with a primary outcome that was usually change in glycated hemoglobin. Virtually all RCTs were high-quality, multicentre, placebo-controlled trials. A total of 96% (1192/1244) of heart failure events were prespecified, blindly adjudicated and required hospital admission. Pooled results suggested a 13% increase in heart failure (relative risk [RR] 1.13, 95% confidence interval [CI] 1.01-1.26, I2 = 0%; 32 RCTs, n = 54 640, 1244 events). When including only the 3 large RCTs, the increase was similar, but not significant (RR 1.14, 95% CI 0.97-1.32; 3 RCTs, n = 36 543, 1169 adjudicated events; number needed to harm 246) owing to heterogeneity (I2 = 42%), which lead to wider CIs, because SAVOR-TIMI 53 showed increased heart failure (RR 1.26, 95% CI 1.06-1.49) and TECOS showed no effect (RR 1.00, 95% CI 0.83-1.19).

INTERPRETATION

Despite pooled data from 79 867 patients, whether DPP-4 inhibitors increase heart failure overall or exhibit within-class differences remains unresolved. Our results highlight the importance of ongoing trials that are comparing DPP-4 inhibitors to placebo, although no large cardiovascular-safety RCTs are comparing different DPP-4 inhibitors to each other; consequently, these will address the overall but not class-difference question.

Incretin-Based Therapy and Risk of Pancreatic Cancer in Patients with Type 2 Diabetes Mellitus: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The present study aims to evaluate the risk of pancreatic cancer with incretin-based therapy among patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched EMBASE, MEDLINE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for eligible studies published up to March 06 2016. This meta-analysis includes all studies reporting adverse events of pancreatic cancer with use of incretin-based therapies compared with placebo or non-incretin anti-diabetic drugs in patients with T2DM. We used fixed-effect model to compare pooled relative risk (RR) with related 95% confidence intervals (CI).

RESULTS

A total of 159 randomized trials were identified. Out of these, 135 studies were excluded as pancreatic cancer occurrence had not been included as an end point. The remaining 24 trials enrolling 47,904 participants were further assessed. Overall, no increased risk of pancreatic cancer were detected in association with incretin-based treatment (RR = 0.7, 95% CI 0.37-1.05). The incidence of pancreatic neoplasm was even lower among incretin-based groups than controls (RR = 0.50, 95% CI 0.29-0.87) in trials with duration more than 104 weeks. There was even decreased risk of pancreatic cancer within groups paralleled by incretin-matched placebos (RR = 0.55, 95% CI 0.32-0.93) than by non-incretin anti-diabetic drugs. Neither monotherapy (RR = 0.62, 95% CI 0.38-1.01) nor combination regimen (RR = 0.92, 95% CI 0.45-1.90) of incretin mimetics increased the risk of pancreatic cancer.

CONCLUSION

This meta-analysis shows that incretin-based therapies are not associated with increase in the risk of pancreatic cancer. Interestingly, subgroup analyses suggested lower risk of pancreatic cancer in incretin groups than placebo in long-term studies (>104 weeks). Considering the inconsistent results among randomized trials and previous epidemiological investigations, more such studies should be conducted to clarify the existence or non-existence of this association.

FUNDING

This work was supported by grants from the National Natural Science Foundation of China (Nos. 81270476 and 81470830).

Cardiovascular effects of dipeptidyl peptidase-4 inhibitor in diabetic patients with and without established cardiovascular disease: a meta-analysis and systematic review

OBJECTIVES

We aim to conduct a meta-analysis, by stratifying diabetic patients with or without clinical cardiovascular diseases (CVD), to explore whether there are different cardiovascular effects of dipeptidyl peptidase-4 inhibitors (DPP-4is) on these two different classes of diabetic patients.

METHODS

We searchedMedline,Embase, theCochrane Libraryand ClinicalTrials.gov for relevant randomized controlled trials (RCTs). The included trials are divided into CVD (+) trials (subjects with established CVD), and CVD (-) trials (subjects with no CVD). We use all-cause mortality and cardiovascular outcomes as primary endpoints.

RESULTS

(1) Three CVD (+) trials were included and 36,895 subjects were enrolled with a mean follow-up duration of 127.1 weeks. The pooled results showed that DPP-4is treatment, compared with the placebo, did not significantly affect all-cause mortality (RR, 1.03; 95% CI, 0.95 to 1.11), cardiovascular death (1.01, 0.91 to 1.12), myocardial infarction (0.98, 0.88 to 1.08) or stroke (1.02, 0.88 to 1.18) in diabetic patients with coexisting CVD history; however, it significantly increased the risk of heart failure (1.14, 1.01 to 1.27) in this population. 2) Thirty-five CVD (-) trials were included, and 29,600 patients were enrolled with a mean follow-up duration of 77.8 weeks. The analysis comparing DPP-4is with the placebo control showed that DPP-4is treatment did not significantly affect the risk of all-cause mortality or cardiovascular outcomes in diabetic patients free of CVD history. However, when compared with the active control, the pooling data showed that DPP-4is had a significant reduction on the risk of stroke (0.58, 0.34 to 0.99) but did not significantly affect the risk of all-cause mortality and other cardiovascular outcomes.

CONCLUSION

DPP-4is may have no cardiovascular protective effects in diabetic patients with coexisting CVD, while there is a lack of definitive evidence supporting the cardiovascular benefits of DPP-4is treatment among diabetic patients free of CVD history.

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.

Population pharmacodynamic analysis of hemoglobin A1c-lowering effects by adding treatment of DPP-4 inhibitors (sitagliptin) in type 2 diabetes mellitus patients based on electronic medical records

AIM

To develop a population pharmacodynamic (PPD) model describing the time course for the hemoglobin A1c (HbA1c)-lowering effects of adding treatment of DPP-4 inhibitors and to assess the efficacy of combination therapy in type 2 diabetes mellitus patients based on electronic medical records.

METHODS

Information on patients was collected retrospectively from electronic medical records. Of the 4 DPP-4 inhibitors used, we focused on sitagliptin as it had the best time-response relationships. A physiological indirect response model was developed to describe changes in HbA1c levels.

RESULTS

An indirect response model, based on the 1300 HbA1c levels of 160 patients, described the time course for the HbA1c-lowering effects of adding sitagliptin. The combination with pioglitazone decreased the HbA1c synthesis rate by 7.74% relative to without pioglitazone. Bayesian forecasting based on the final PDD model using the first two HbA1c observations, before and within 30days after the addition of sitagliptin, gave a precise prediction of HbA1c-lowering effects individually.

CONCLUSIONS

Our PPD model quantitatively described the beneficial effects of combination therapy with pioglitazone and sitagliptin. The proposal methodology is also expected to be applicable to other medicines based on electronic medical records in clinical practice.

Linagliptin and pioglitazone combination therapy versus monotherapy with linagliptin or pioglitazone: A randomised, double-blind, parallel-group, multinational clinical trial

Linagliptin plus pioglitazone single-pill combinations were evaluated. Patients (n = 936) with insufficient glycaemic control, despite lifestyle interventions, were randomised for 30 weeks to either monotherapy with linagliptin 5 mg; pioglitazone 15, 30 or 45 mg; or single-pill combination with linagliptin 5 mg plus pioglitazone 15, 30 or 45 mg. An extension (⩽54 weeks) planned to evaluate linagliptin plus pioglitazone 30 or 45 mg single-pill combinations was not completed due to a protocol amendment. Adjusted mean (95% confidence interval) differences in HbA1c change from baseline at week 30 for linagliptin plus pioglitazone 15, 30 and 45 mg were -0.17% (-0.41, 0.07), -0.37% (-0.60, -0.14) and -0.41% (-0.64, -0.18) versus pioglitazone monotherapies, respectively, and -0.44% (-0.67, -0.20), -0.68% (-0.91, -0.44) and -0.89% (-1.12, -0.66) versus linagliptin monotherapy, respectively. Single-pill combinations were generally well tolerated. Hypoglycaemia frequency was ⩽1.5% per group. Linagliptin plus pioglitazone combinations were efficacious, with safety profiles comparable to the individual monotherapies.

Prediction of the effect on antihyperglycaemic action of sitagliptin by plasma active form glucagon-like peptide-1

AIM: To investigate whether active glucagon-like peptide-1 (GLP-1) is a prediction Factor of Effect of sitagliptin on patients with type 2 diabetes mellitus (GLP-1 FEST:UMIN000010645).

METHODS: Seventy-six patients with type 2 diabetes, who had insufficient glycemic control [Hemoglobin A1c (HbA1c) ≥ 7%] in spite of treatment with metformin and/or sulfonylurea, were included in the investigation. Patients were divided into three groups by tertiles of fasting plasma active GLP-1 level, before the administration of 50 mg sitagliptin.

RESULTS: At baseline, body mass index, serum UA, insulin and HOMA-IR were higher in the high active GLP-1 group than in the other two groups. The high active GLP-1 group did not show any decline of HbA1c (7.6% ± 1.4% to 7.5% ± 1.5%), whereas the middle and low groups indicated significant decline of HbA1c (7.4 ± 0.7 to 6.8 ± 0.6 and 7.4 ± 1.2 to 6.9 ± 1.3, respectively) during six months. Only the low and middle groups showed a significant increment of active GLP-1, C-peptide level, a decreased log and proinsulin/insulin ratio after administration. In logistic analysis, the low or middle group is a significant explanatory variable for an HbA1c decrease of ≥ 0.5%, and its odds ratio is 4.5 (1.40-17.6) (P = 0.01) against the high active GLP-1 group. This remains independent when adjusted for HbA1c level before administration, patients’ medical history, medications, insulin secretion and insulin resistance.

CONCLUSION: Plasma fasting active GLP-1 is an independent predictive marker for the efficacy of dipeptidyl peptidase 4 inhibitor sitagliptin.

DPP-4 inhibitor therapy and bone fractures in people with Type 2 diabetes - A systematic review and meta-analysis

AIM

Fracture risk is higher in older adults with Type 2 diabetes mellitus (T2DM). Oral glucose-lowering medications have different effects on bone metabolism. The purpose of this study is to appraise the evidence from literature and determine the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor on the risk of developing bone fractures.

METHODS

Using Boolean search terms, the search strategy combined synonyms of 'fracture' and 'DPP-4 inhibitor'. Comprehensive electronic databases which include EMBASE, MEDLINE, the EMA and the WHO ICTRP databases were searched for randomised controlled trial (RCT) studies which compared a DPP-4 inhibitor with an active comparator or placebo amongst patients with T2DM. Meta-analysis was performed to compare DPP-4 inhibitor with either an active comparator or a placebo. The outcome measure was the presence or absence of fracture.

RESULTS

The search yielded 5061 records relating to fractures and DPP-4 inhibitor, from which 51 eligible RCTs were selected for meta-analysis (N=36,402). Thirty-seven (37) studies compared DPP-4 inhibitor with placebo (n=23,974), while fourteen (14) studies (n=12,428) compared DPP-4 inhibitor with an active comparator. The mean age of patients was 57.5±5.4years, the average glycated haemoglobin (HbA1c) was 8.2%, while the average BMI was 30±2kg/m(2). Overall, there was no significant association of fracture events with the use of DPP-4 inhibitor when compared with placebo (OR; 0.82, 95% CI 0.57-1.16, P=0.9) or when DPP-4 inhibitor was compared against an active comparator (OR; 1.59, 95% CI 0.91-2.80, P=0.9).

CONCLUSION

This study offers a larger, up-to-date review of the subject. The meta-analysis showed that there was no significant association between DPP-4 inhibitor use and the incidence of fractures.

Dipeptidyl peptidase-4 inhibitors and risk of heart failure in type 2 diabetes: systematic review and meta-analysis of randomised and observational studies

OBJECTIVES

To examine the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and the risk of heart failure or hospital admission for heart failure in patients with type 2 diabetes.

DESIGN

Systematic review and meta-analysis of randomised and observational studies.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov searched up to 25 June 2015, and communication with experts.

ELIGIBILITY CRITERIA

Randomised controlled trials, non-randomised controlled trials, cohort studies, and case-control studies that compared DPP-4 inhibitors against placebo, lifestyle modification, or active antidiabetic drugs in adults with type 2 diabetes, and explicitly reported the outcome of heart failure or hospital admission for heart failure.

DATA COLLECTION AND ANALYSIS

Teams of paired reviewers independently screened for eligible studies, assessed risk of bias, and extracted data using standardised, pilot tested forms. Data from trials and observational studies were pooled separately; quality of evidence was assessed by the GRADE approach.

RESULTS

Eligible studies included 43 trials (n=68,775) and 12 observational studies (nine cohort studies, three nested case-control studies; n=1,777,358). Pooling of 38 trials reporting heart failure provided low quality evidence for a possible similar risk of heart failure between DPP-4 inhibitor use versus control (42/15,701 v 33/12,591; odds ratio 0.97 (95% confidence interval 0.61 to 1.56); risk difference 2 fewer (19 fewer to 28 more) events per 1000 patients with type 2 diabetes over five years). The observational studies provided effect estimates generally consistent with trial findings, but with very low quality evidence. Pooling of the five trials reporting admission for heart failure provided moderate quality evidence for an increased risk in patients treated with DPP-4 inhibitors versus control (622/18,554 v 552/18,474; 1.13 (1.00 to 1.26); 8 more (0 more to 16 more)). The pooling of adjusted estimates from observational studies similarly suggested (with very low quality evidence) a possible increased risk of admission for heart failure (adjusted odds ratio 1.41, 95% confidence interval 0.95 to 2.09) in patients treated with DPP-4 inhibitors (exclusively sitagliptin) versus no use.

CONCLUSIONS

The relative effect of DPP-4 inhibitors on the risk of heart failure in patients with type 2 diabetes is uncertain, given the relatively short follow-up and low quality of evidence. Both randomised controlled trials and observational studies, however, suggest that these drugs may increase the risk of hospital admission for heart failure in those patients with existing cardiovascular diseases or multiple risk factors for vascular diseases, compared with no use.

Determinants of Glycemic Response to Add-On Therapy with a Dipeptidyl Peptidase-4 Inhibitor: A Retrospective Cohort Study Using a United Kingdom Primary Care Database

BACKGROUND

Apart from baseline glycated hemoglobin (HbA1c), little is known about clinical parameters that affect glycemic response to a dipeptidyl peptidase-4 (DPP4) inhibitor when used in routine clinical practice. We aimed to use a large primary care database to assess the variability in response to a DPP4 inhibitor when used as add-on therapy.

MATERIALS AND METHODS

Data on 25,386 patients with type 2 diabetes, newly treated with a DPP4 inhibitor (2007-2013), were sourced from a United Kingdom general practice database via the Health Improvement Network database. Baseline clinical parameters of patients (n = 13,525) for whom a DPP4 inhibitor was added because of suboptimal glucose control (HbA1c >7%) were compared with 12-month follow-up data. An optimum response to the DPP4 inhibitor was defined as an HbA1c level of <7.0% at 12 months. Descriptive analyses and unadjusted comparisons using χ(2) and t tests were carried out to ascertain glycemic and body weight responses to treatment intensification with a DPP4 inhibitor. Predictor of response analyses were performed using multivariate logistic regression.

RESULTS

Overall, 1,708 (13%) of our study population achieved an HbA1c level of <7%. Intensification with a DPP4 inhibitor was associated with significant reductions in HbA1c (-0.5%), body weight (-0.9 kg), and total cholesterol (-0.1 mmol/L) (P < 0.001). Independent predictors of achieving optimal HbA1c target of <7% included the use of metformin (adjusted odds ratio [OR] = 2.58; 95% confidence interval [CI], 2.18-3.04) and use of metformin plus sulfonylurea (1.42; 95% CI, 1.21-1.68) as opposed to no use. The independent predictors of suboptimal glucose control included a higher baseline HbA1c level (OR = 0.64; 95% CI, 0.61-0.68) (i.e., 1% increase in HbA1c was associated with a 36% reduced likelihood of response), longer diabetes duration (per every year increase) (OR = 0.85; 95% CI, 0.83-0.88), and intensification therapy below 9 months compared with 9-12 months.

CONCLUSIONS

There is a significant variability in glycemic response to a DPP4 inhibitor in routine practice. The best effect is achieved as add-on to metformin and metformin plus sulfonylurea, but responses are significantly lower with increased diabetes duration and among patients with high HbA1c levels at baseline.

Risk of pancreatic adverse events associated with the use of glucagon-like peptide-1 receptor agonist and dipeptidyl peptidase-4 inhibitor drugs: A systematic review and meta-analysis of randomized trials

AIM: To systematically assess risk of pancreatic adverse events with glucagon-like peptide-1 (GLP-1) receptor agonist and dipeptidyl peptidase-4 (DPP-4) inhibitor drugs.

METHODS: We searched PubMed, Embase, CINAHL, Cochrane review of clinical trials, pharmaceutical company clinical trials register, United States Food and Drug Administration website, European Medicines Agency website and ClinicalTrials.gov for randomized controlled trials from inception to October 2013. Randomized control trial studies were selected for inclusion if they reported on pancreatic complication events and/or changes in pancreatic enzyme levels (serum amylase and serum lipase) as adverse events or as serious adverse events for patients who were on GLP-1 receptor agonist and DPP-4 inhibitor drugs. Two independent reviewers extracted data directly. We performed Peto odds ratio (OR) fixed effect meta-analysis of pancreatic adverse events a, and assessed heterogeneity with the I² statistic.

RESULTS: Sixty-eight randomized controlled trials were eligible. A total of 60720 patients were included in our analysis of the association of risk of pancreatic complication events with GLP-1 agents. A total of 89 pancreatic related adverse events occurred among the GLP-1 agents compared to 74 events among the controls. There was a statistically significant increased risk of elevation of pancreatic enzymes associated with GLP-1 agents compared with control (Peto OR = 3.15, 95%CI: 1.56-6.39, P = 0.001, I² = 0%). There was no statistically significant difference in the risk of pancreatic adverse event associated with GLP-1 agent compared with controls (Peto OR = 1.00, 95%CI: 0.73-1.37, P = 1.00, I² = 0%). There were a total of 71 pancreatitis events in patients on GLP-1 agents and 56 pancreatitis events occurred in the control patients. There were 36 reports of pancreatic cancer in these studies. Of these cases, 2 used linagliptin, 2 used alogliptin, 1 used vildagliptin, 7 used saxagliptin while 6 used sitagliptin. The remaining 18 cases occurred among controls.

CONCLUSION: Although GLP-1 based agents are associated with pancreatic enzyme elevation, we were unable to confirm a significant risk of pancreatitis or pancreatic cancer.

Four-Year Durability of Initial Combination Therapy with Sitagliptin and Metformin in Patients with Type 2 Diabetes in Clinical Practice; COSMIC Study

OBJECTIVES

We investigated the efficacy of initial combination therapy with sitagliptin and metformin in patients with type 2 diabetes for 4 years in clinical practice.

METHODS

Between 2009 and 2010, we reviewed 1,178 patients with type 2 diabetes (HbA1c ≥7.5% or 58 mmol/mol) prescribed initial combination therapy with sitagliptin and metformin. After excluding 288 patients without a second follow-up, 890 individuals (age, 58.0 ± 12.5 years; BMI, 25.4 ± 3.5 kg/m2; HbA1c, 8.6 ± 1.1%) were followed up with every 3-6 months for 4 years. Homeostasis model assessments for insulin resistance and β-cell function (HOMA-β) were recorded at baseline. The response criterion was HbA1c reduction by ≥0.8% from baseline or attainment of the target HbA1c (≤7.0% or 53 mmol/mol). At the end of every year of treatment, changes in HbA1c from the baseline were assessed.

RESULTS

After 1 year, 72.2% of patients with initial combination therapy had responded, defined as HbA1c reduction ≥0.8% or attainment of the target HbA1c ≤7.0%. After 4 years, 35.4% of the patients still showed a response, with an HbA1c level of 7.0 ± 0.9%. A high HbA1c level at baseline was the most significant independent predictor of the long-term response (P<0.001). In addition, low HOMA-β was a significant predictor of a greater reduction in HbA1c. This treatment was generally well tolerated over the 4-year follow-up period, without any serious adverse events.

CONCLUSIONS

This real-world follow-up study shows a persistent glucose-reducing effect of initial combination therapy with sitagliptin and metformin for up to 4 years.

A comparison of glycaemic effects of sitagliptin and sulfonylureas in elderly patients with type 2 diabetes mellitus

INTRODUCTION

In the USA, 45% of patients with type 2 diabetes mellitus (T2DM) are elderly (≥ 65 years old). In general, use of sulfonylurea increases with patient age as does the associated risk for hypoglycaemia, and the consequences of hypoglycaemia can be more pronounced in elderly patients. Sitagliptin, a DPP-4 inhibitor, improves glycaemic control in adult patients of all ages with T2DM, with a low risk of hypoglycaemia when used alone or in combination with other antidiabetic agents that are not generally associated with hypoglycaemia when used independently.

METHODS

In a post hoc analysis, pooled data from elderly patients who participated in one of three double-blind studies comparing the effects of therapy with sitagliptin (100 mg/day) vs. sulfonylurea (in titrated doses) were analysed for changes from baseline in HbA1c, fasting plasma glucose (FPG), and body weight and for the incidence of reported symptomatic hypoglycaemia. In these studies, patients on diet alone or metformin were randomised to sitagliptin or glipizide for 104 weeks (studies 1 and 2) or glimepiride for 30 weeks (study 3). The analysis included 372 elderly patients who completed a trial through 25 or 30 weeks.

RESULTS

Both HbA1c and FPG decreased from baseline with each treatment, with no statistically significant differences between treatments. A significantly lower incidence of reported hypoglycaemia was observed with sitagliptin compared with sulfonylurea (6.2% vs. 27.8%; p < 0.001). Body weight decreased significantly with sitagliptin but not with sulfonylurea. Significantly more patients on sitagliptin than on sulfonylureas achieved a composite end-point of >0.5% HbA1c reduction with no reported hypoglycaemia or increase in body weight (44.1% vs. 16.0%; p < 0.001).

CONCLUSION

In this analysis of elderly patients with T2DM, compared with sulfonylurea, sitagliptin provided similar glycaemic efficacy with less hypoglycaemia and with body weight loss.

Pharmacokinetics and clinical evaluation of the alogliptin plus pioglitazone combination for type 2 diabetes

INTRODUCTION

Type 2 diabetes is a complex disease with multiple defects, which generally requires a combination of several pharmacological approaches to reach glucose control targets. A unique fixed-dose combination combines a thiazolidinedione (pioglitazone) and a dipeptidyl peptidase-4 inhibitor (alogliptin).

AREA COVERED

An extensive literature search was performed to analyze the pharmacokinetics of pioglitazone and alogliptin when used separately and in combination as well as to summarize clinical and toxicological considerations about the combined therapy.

EXPERT OPINION

Pioglitazone, a potent insulin sensitizer, and alogliptin, an incretin-based agent that potentiates post-meal insulin secretion and reduces glucagon secretion, have complementary mechanisms of action. The clinical efficacy of a combined therapy is superior to any single therapy in patients treated with diet or with metformin (with or without sulphonylurea). These two drugs can be administered once daily, with or without a meal. No clinically relevant pharmacokinetic interactions between the two agents have been described and the fixed-dose combination has shown bioequivalence with alogliptin and pioglitazone given separately. Combining alogliptin with pioglitazone does not alter the safety profile of each compound. Weight gain observed with pioglitazone may be limited with the addition of alogliptin. The concern of an increased risk of heart failure remains to be better investigated.

Combination Therapy When Metformin Is Not an Option for Type 2 Diabetes

Objective: Consensus on combination options for patients with type 2 diabetes mellitus (T2DM) unable to use metformin is lacking. This review summarizes data describing–non-metformin based combination therapy. Data Sources: PubMed searches (January 1990 to August 2014) were conducted with terms for newer drug therapies alone and with the term combination; filters were applied for Clinical Trial, Meta Analysis, and English language. Study Selection and Data Extraction: Results were reviewed for multicenter, randomized controlled trials of non-metformin–based combination therapy conducted in the past 5 years and specific to the US or multinational populations. Data Synthesis: Although multiple injectable and oral agents have been studied in combination with metformin for management of T2DM, data are more limited for combinations without metformin. Combinations of incretins (injectable glucagon-like peptide-1 receptor agonists or oral dipeptidyl peptidase-4 [DPP-4] inhibitors) with a sulfonylurea, thiazolidinedione, or insulin are well studied and provide greater glucose-lowering efficacy than monotherapy. Incretins are associated with a low risk of hypoglycemia when used as monotherapy; the dosage of sulfonylurea or insulin should be reduced when used in combination. Newer studies are investigating the combined use of an oral sodium-glucose cotransporter 2 inhibitor and a DPP-4 inhibitor. In a recent study, reductions in glycated hemoglobin (A1C) of 1.1% to 1.2% and reduced weight with no additive risk of hypoglycemia were observed. Conclusions: Selecting the most appropriate combination therapy for patients with T2DM requires balancing clinical benefits with the risks, such as weight gain and hypoglycemia. Treatment approaches should be individualized for vulnerable patient populations for whom metformin is not appropriate.

Safety of sitagliptin in elderly patients with type 2 diabetes: a pooled analysis of 25 clinical studies

OBJECTIVE

The aim of this study was to evaluate the safety and tolerability of sitagliptin 100 mg/day in elderly patients with type 2 diabetes.

DESIGN

A post hoc pooled analysis of 25 randomized, double-blind, parallel group clinical studies with results available as of 1 December 2011.

SETTING

Multicenter, international clinical trials.

SUBJECTS

Patients with type 2 diabetes aged 65 years or older.

INTERVENTIONS

Patients were randomized to sitagliptin 100 mg/day (n = 1,261) or a comparator (n = 1,185) for 12 weeks to 2 years.

MAIN OUTCOME MEASURES

In each study, investigators reported serious and non-serious adverse events that occurred during the study, and serious adverse events occurring within 14 days following the last dose of study drug. This analysis used patient-level data from each study to assess the exposure-adjusted incidence rates of specific adverse events that occurred following initiation of study drug.

RESULTS

Summary measures of adverse events overall were similar between the sitagliptin and non-exposed (active comparator or placebo) groups, except for higher incidences of deaths and drug-related adverse events in the non-exposed group. Incidence rates of specific adverse events were generally similar between the two groups, with the exception of hypoglycemia. A lower incidence rate of hypoglycemia was observed in the sitagliptin group compared with the non-exposed group [7.0 vs. 14.3 per 100 patient-years; difference -7.6 (95 % CI -11.2 to -4.3]), primarily due to greater use of sulfonylureas in the non-exposed group.

CONCLUSIONS

In this pooled safety analysis of elderly patients with type 2 diabetes, treatment with sitagliptin 100 mg/day was generally well tolerated for up to 2 years.

Cardiovascular safety of sitagliptin in patients with type 2 diabetes mellitus: a pooled analysis

Objective

To compare the incidence of cardiovascular events and mortality in patients with type 2 diabetes mellitus treated with sitagliptin or non-sitagliptin comparators.

Methods

A post hoc assessment of cardiovascular safety in 14,611 patients was performed by pooling data from 25 double-blind studies, which randomised patients at baseline to sitagliptin 100 mg/day or a non-sitagliptin comparator (i.e., non-exposed). Included studies were limited to those at least 12 weeks in duration (range: 12 to 104 weeks). Patient-level data were used in this analysis of major adverse cardiovascular events (MACE) including ischaemic events and cardiovascular deaths. Analyses were performed in three cohorts: the entire 25-study cohort, the cohort from placebo-controlled portions of studies (n=19), and the cohort from studies comparing sitagliptin to a sulphonylurea (n=3).

Results

In the entire cohort analysis, 78 patients had at least 1 reported MACE-related event, with 40 in the sitagliptin group and 38 in the non-exposed group. The exposure-adjusted incidence rate was 0.65 per 100 patient-years in the sitagliptin group and 0.74 in the non-exposed group (incidence rate ratio = 0.83 [95% confidence interval (CI): 0.53, 1.30]). In the analysis comparing sitagliptin to placebo, the exposure-adjusted incidence rate was 0.80 per 100-patient-years with sitagliptin and 0.76 with placebo (incidence rate ratio = 1.01 [95% CI: 0.55, 1.86]). In the analysis comparing sitagliptin to sulphonylurea, the exposure-adjusted incidence rate was 0.00 per 100 patient-years with sitagliptin and 0.86 with sulphonylurea (incidence rate ratio = 0.00 [95% CI: 0.00, 0.31]).

Conclusion

A pooled analysis of 25 randomised clinical trials does not indicate that treatment with sitagliptin increases cardiovascular risk in patients with type 2 diabetes mellitus. In a subanalysis, a higher rate of cardiovascular-related events was associated with sulphonylurea relative to sitagliptin.