Effects of saxagliptin added to sub-maximal doses of metformin compared with uptitration of metformin in type 2 diabetes: the PROMPT study

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.

Reduction in HbA1c with SGLT2 inhibitors vs. DPP-4 inhibitors as add-ons to metformin monotherapy according to baseline HbA1c: A systematic review of randomized controlled trials

AIMS

This study compared the reduction of glycated haemoglobin (HbA1c) with sodium-glucose cotransporter type-2 inhibitors (SGLT2is) vs. dipeptidyl peptidase-4 inhibitors (DPP-4is) as add-ons to metformin in patients with type 2 diabetes mellitus (T2DM), with a specific focus on HbA1c changes according to baseline HbA1c.

MATERIALS AND METHODS

Electronic databases were scrutinized for randomized controlled trials (RCTs) evaluating the reduction of HbA1c from baseline (Δ HbA1c) with an SGLT2i or DPP-4i in patients with T2DM not well controlled by metformin monotherapy. The endpoint was Δ HbA1c using both indirect and direct comparisons.

RESULTS

Overall, Δ HbA1c was slightly greater with SGLT2is (-0.80±0.20% from 8.03±0.35%; 44 analyses, 29 RCTs, 15 with two doses, n=9321) than with DPP-4is (-0.71±0.23% from 8.05±0.43%; 61 analyses, 59 RCTs, n=17,914; P=0.0354). When the mean baseline HbA1c was<8% ([64mmol/mol] 7.79±0.15% vs. 7.71±0.23%), Δ HbA1c averaged -0.735±0.17% vs. -0.62±0.16% (P=0.0117) with SGLT2is vs. DPP-4is, respectively. However, this difference vanished when the mean baseline HbA1c was≥8% (-0.87±0.22% from 8.27±0.32% with SGLT2is vs. -0.80±0.24% from 8.35±0.33% with DPP-4is; P=0.2756). The relationship between Δ HbA1c and baseline HbA1c was only slightly stronger with SGLT2is (slope: -0.39, r²=-0.43; P<0.0001) than with DPP-4is (slope: -0.26, r²=-0.25; P<0.0001).

CONCLUSION

Because of the small difference in Δ HbA1c whatever the baseline HbA1c level with SGLT2is vs. DPP-4is as add-ons to metformin, choosing between these glucose-lowering agents in clinical practice should be based on other efficacy criteria (such as weight and blood pressure changes, cardiovascular and renal protection) or on safety profiles rather than on HbA1c levels.

Comparative Effectiveness of Metformin Dosage Uptitration Versus Adding Another Antihyperglycemic Medication on Glycemic Control in Type 2 Diabetes Patients Failing Initial Metformin Monotherapy: A Retrospective Cohort Study

Metformin is recommended as first-line treatment for type 2 diabetes (T2D). A disadvantage of metformin is the possibility of gastrointestinal adverse effects in some patients. Many T2D patients are not able to achieve/maintain glycemic control from initial metformin treatment and receive treatment intensification by means of metformin dosage uptitration or addition of a T2D drug. This retrospective study evaluated the comparative effectiveness of these 2 treatment intensification strategies. The study cohort included T2D patients at a US integrated health care system who: were initiated on metformin monotherapy (MM) during January 2009 - September 2013; had an uncontrolled HbA1c (≥7%) after at least 90 days of MM; and received metformin dosage uptitration or an additional T2D medication within 6 months of the uncontrolled HbA1c reading. Statistical techniques included Kaplan-Meier curves and Cox proportional hazards regression. The study cohort included 1167 patients, 52.4% male and 65.1% white, with a mean age of 55.3 (±11.9) years. Of these, 49.1% received metformin dosage uptitration and 50.9% received an additional T2D medication. Metformin dosage uptitration was as effective as adding another T2D medication with the probability of not achieving glycemic control (P = 0.599) and rate of glycemic control (adjusted hazard ratio = 1.28, 95% confidence interval = 0.98-1.68) within 6 months of intensification not significantly different between the 2 groups. Metformin dosage uptitration could be a preferable initial intensification strategy in patients failing initial MM unless there is a concern for gastrointestinal adverse effects, in which case adding a T2D medication might be preferable.

Efficacy and safety of saxagliptin in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVE

To evaluate the comparative efficacy and safety of saxagliptin for type 2 diabetes (T2D).

METHODS

A systematic search of PubMed, Embase, the Cochrane Library, Web of Science, ClinicalTrials.gov and two Chinese databases for randomized controlled trials (RCTs) comparing saxagliptin with placebo or active comparators was performed up to July 2017. A complementary search was done to cover literature until March 2018. For continuous data, estimates were pooled using inverse variance methodology to calculate weighted mean differences (WMDs). Dichotomous data were presented as Mantel-Haenzel risk ratios (RRs).

RESULTS

Thirty-nine references of 30 RCTs involving 29,938 patients were analyzed. Compared with placebo, saxagliptin significantly reduced glycated hemoglobin (HbA1c, WMD -0.52%, 95% CI -0.60 to -0.44) and fasting plasma glucose (WMD -13.78 mg/dL, 95% CI -15.31 to -12.25), and increased the proportion of patients achieving HbA1c <7% (RR 1.64, 95% CI 1.53 to 1.75). When combined with submaximal-dose metformin, saxagliptin significantly increased the proportion of patients achieving HbA1c <7% compared with acarbose (RR 2.38, 95% CI 1.17 to 4.83) and uptitrated metformin (RR 1.30, 95% CI 1.04 to 1.63). Saxagliptin was similar to other DPP-4 inhibitors but inferior to liraglutide and dapagliflozin on glycemic control. Saxagliptin significantly decreased the incidences of overall adverse events compared with acarbose (RR 0.71, 95% CI 0.57 to 0.89) and liraglutide (RR 0.41, 95% CI 0.24 to 0.71) when added to metformin. Weight gain and hypoglycemia with saxagliptin was slightly but significantly higher than placebo and lower than sulfonylureas. Saxagliptin did not increase the risk of arthralgia, heart failure, pancreatitis and other adverse events.

CONCLUSIONS

Generally, saxagliptin has similar efficacy compared with most oral antidiabetic drugs and may be more effective than acarbose, while having a better safety profile than both acarbose and sulfonylureas.

Initiating therapy in patients newly diagnosed with type 2 diabetes: Combination therapy vs a stepwise approach

There is clear evidence that achieving glycaemic targets reduces the risk of developing complications as a result of type 2 diabetes (T2D). Many patients, however, continue to have suboptimal glycaemic control because of issues that include unclear advice on how to achieve these targets as well as clinical inertia. The two management approaches recommended for patients newly diagnosed with T2D are stepwise and combination therapy, each of which has advantages and disadvantages. Stepwise therapy may result in good patient adherence and allow greater individualization of therapy, and minimization of side effects and cost, and so may be appropriate for patients who are closer to goal. Stepwise therapy, however, may also lead to frequent delays in achieving glycaemic goals and longer exposure to hyperglycaemia. Combination therapy, which is now emerging as an important therapy option, has a number of potential advantages over stepwise therapy, including reduction in clinical inertia and earlier and more frequent achievement of glycated haemoglobin goals by targeting multiple pathogenic mechanisms simultaneously, which may more effectively delay disease progression. Compared with stepwise therapy, the disadvantages of combination therapy include reduced patient adherence resulting from complex, multi-drug regimens, difficulty determining the cause of poor efficacy and/or side effects, patient refusal to accept disease, and higher cost. Fixed-dose and fixed-ratio combinations are novel therapeutic approaches which may help address several issues of treatment complexity and patient burden associated with combination therapy comprising individual drugs. The choice of which drugs to administer and the decision to use stepwise vs combination therapy, however, should always be made on an individualized basis.

Understanding and overcoming metformin gastrointestinal intolerance

Metformin is the most widely prescribed drug for patients with type 2 diabetes mellitus and the first-line pharmacological option as supported by multiple international guidelines, yet a rather large proportion of patients cannot tolerate metformin in adequate amounts because of its associated gastrointestinal (GI) adverse events (AEs). GI AEs typically encountered with metformin therapy include diarrhoea, nausea, flatulence, indigestion, vomiting and abdominal discomfort, with diarrhoea and nausea being the most common. Although starting at a low dose and titrating slowly may help prevent some GI AEs associated with metformin, some patients are unable to tolerate metformin at all and it may also be difficult to convince patients to start metformin again after a bout of GI AEs. Despite this clinical importance, the underlying mechanisms of the GI intolerance associated with metformin are poorly known. In the present review, we discuss: the epidemiology of metformin-associated GI intolerance and its underlying mechanisms; genotype variability and associated factors affecting metformin GI intolerance, such as comorbidities, co-medications and bariatric surgery; clinical consequences and therapeutic strategies to overcome metformin GI intolerance. These strategies include appropriate titration of immediate-release metformin, use of extended-release metformin, the promise of delayed-release metformin and gut microbiome modulators, as well as alternative pharmacological therapies when metformin cannot be tolerated at all. Given the available data, all efforts should be made to maintain metformin before considering a shift to another drug therapy.

Emerging use of combination therapies for the management of type 2 diabetes - focus on saxagliptin and dapagliflozin

AIMS

The aim of this article is to review the safety and efficacy data of dapagliflozin, saxagliptin, and their combination in the management of patients with type 2 diabetes. Evidence for the use of the single-tablet combination formulation is also presented.

METHODS

A nonsystematic literature review was performed using the Ovid, PubMed, and Google Scholar databases.

RESULTS

The addition of dapagliflozin/saxagliptin to metformin can lower mean hemoglobin A1c by as much as 1.47% and lead to weight loss of 0.5-2.0 kg. The risk of genital infections with combination therapy is lower than observed with dapagliflozin alone, suggestive of a protective effect. Adverse event risk at 52-week follow-up was not increased beyond that seen with either monotherapy.

CONCLUSION

Dapagliflozin/saxagliptin combination is generally well tolerated and is an effective tool in helping patients with diabetes improve glycemic control.

NRF2 activation by antioxidant antidiabetic agents accelerates tumor metastasis

Cancer is a common comorbidity of diabetic patients; however, little is known about the effects that antidiabetic drugs have on tumors. We discovered that common classes of drugs used in type 2 diabetes mellitus, the hypoglycemic dipeptidyl peptidase-4 inhibitors (DPP-4i) saxagliptin and sitagliptin, as well as the antineuropathic α-lipoic acid (ALA), do not increase tumor incidence but increase the risk of metastasis of existing tumors. Specifically, these drugs induce prolonged activation of the nuclear factor E2-related factor 2 (NRF2)-mediated antioxidant response through inhibition of KEAP1-C151-dependent ubiquitination and subsequent degradation of NRF2, resulting in up-regulated expression of metastasis-associated proteins, increased cancer cell migration, and promotion of metastasis in xenograft mouse models. Accordingly, knockdown of NRF2 attenuated naturally occurring and DPP-4i-induced tumor metastasis, whereas NRF2 activation accelerated metastasis. Furthermore, in human liver cancer tissue samples, increased NRF2 expression correlated with metastasis. Our findings suggest that antioxidants that activate NRF2 signaling may need to be administered with caution in cancer patients, such as diabetic patients with cancer. Moreover, NRF2 may be a potential biomarker and therapeutic target for tumor metastasis.

Single nucleotide polymorphisms in the intergenic region between metformin transporter OCT2 and OCT3 coding genes are associated with short-term response to metformin monotherapy in type 2 diabetes mellitus patients

OBJECTIVES

High variability in clinical response to metformin is often observed in type 2 diabetes (T2D) patients, and it highlights the need for identification of genetic components affecting the efficiency of metformin therapy. Aim of this observational study is to evaluate the role of tagSNPs (tagging single nucleotide polymorphisms) from genomic regions coding for six metformin transporter genes with respect to the short-term efficiency.

DESIGN

102 tagSNPs in 6 genes coding for metformin transporters were genotyped in the group of 102 T2D patients treated with metformin for 3 months.

METHODS

Most significant hits were analyzed in the group of 131 T2D patients from Slovakia. Pharmacokinetic study in 25 healthy nondiabetic volunteers was conducted to investigate the effects of identified polymorphisms.

RESULTS

In the discovery group of 102 patients, minor alleles of rs3119309, rs7757336 and rs2481030 were significantly nominally associated with metformin inefficiency (P = 1.9 × 10^-6 to 8.1 × 10^-6). Effects of rs2481030 and rs7757336 did not replicate in the group of 131 T2DM patients from Slovakia alone, whereas rs7757336 was significantly associated with a reduced metformin response in combined group. In pharmacokinetic study, group of individuals harboring risk alleles of rs7757336 and rs2481030 displayed significantly reduced AUC_∞ of metformin in plasma.

CONCLUSIONS

For the first time, we have identified an association between the lack of metformin response and SNPs rs3119309 and rs7757336 located in the 5' flanking region of the genes coding for Organic cation transporter 2 and rs2481030 located in the 5' flanking region of Organic cation transporter 3 that was supported by the results of a pharmacokinetic study on 25 healthy volunteers.

Effects of saxagliptin add-on therapy to insulin on blood glycemic fluctuations in patients with type 2 diabetes: A randomized, control, open-labeled trial

BACKGROUND

To investigate whether saxagliptin add-on therapy to continuous subcutaneous insulin infusion (CSII) further improve blood glycemic control than CSII therapy in patients with newly diagnosed type 2 diabetes (T2D).

METHODS

This was a single-center, randomized, control, open-labeled trial. Newly diagnosed T2D patients were recruited between February 2014 and December 2015. Subjects were divided into saxagliptin add-on therapy to CSII group (n = 31) and CSII therapy group (n = 38). The treatment was maintained for 4 weeks. Oral glucose tolerance test was performed at baseline. Serum samples were obtained before and 30 and 120 minutes after oral administration for glucose, insulin, and C-peptide determination. Continuous glucose monitoring (CGM) was performed before and endpoint.

RESULTS

A total of 69 subjects were admitted. After 4-week therapy, CGM data showed that patients with saxagliptin add-on therapy exhibited further improvement of mean amplitude glycemic excursion (MAGE), the incremental area under curve of plasma glucose >7.8 and 10 mmol/L compared with that of control group. In addition, the hourly mean blood glucose concentrations, especially between 0000 and 0600 in patient with saxagliptin add-on therapy, were significantly lower compared with that of the control patients. Furthermore, patients in saxagliptin add-on group needed lower insulin dose to maintain euglycemic control. In addition, severe hypoglycemic episode was not observed from any group.

CONCLUSION

Saxagliptin add-on therapy to insulin had the ability of further improve blood glycemic controlling, with lower insulin dose required by patients with T2D to maintain euglycemic controlling.

Efficacy, safety and impact on β-cell function of dipeptidyl peptidase-4 inhibitors plus metformin combination therapy in patients with type 2 diabetes and the difference between Asians and Caucasians: a meta-analysis

BACKGROUND

To assess the efficacy, safety and impact on β-cell function of DPP-4 inhibitors plus metformin in T2DM patients and their difference between Asians and Caucasians.

METHODS

We conducted a literature search (from 1 January 2000 to 14 April 2015) for RCTs of DPP-4 inhibitors plus metformin combination therapy in T2DM.

RESULTS

A total of 27 RCTs were included. Compared with metformin, DPP-4 inhibitor plus metformin therapy was associated with higher reduction in HbA1c [-0.61 %, -0.69 to -0.52], FPG [-1.10 mmol/l, -1.29 to -0.92], TC [-0.11 mmol/l, -0.20 to -0.02], TG [-0.21 mmol/l, -0.33 to -0.10], HOMA-IR [-0.19, -0.36 to -0.02], gastrointestinal adverse events [OR 0.86, 0.77-0.97] and higher increment in HOMA-β [10.21, 7.73-12.69]. Comparison of HbA1c, FPG, body weight and HOMA-IR changes between Asian and Caucasian patients did not show a significant between-group difference of -0.05 % (-0.30, 0.20; P = 0.69), 0.17 mmol/l (-0.52, 0.85; P = 0.62), -0.15 kg (-0.64, 0.35; P = 0.53) and 0.27 (-0.98, 1.53; P = 0.64) compared with metformin. Comparisons of HOMA-β between Asian and Caucasian patients showed a significant between-group difference of -7.68 (-14.95, -0.42; P = 0.04).

CONCLUSION

DPP-4 inhibitors and metformin therapy was effective and safe for T2DM patients. The glucose-lowering efficacy of DPP-4 inhibitors was same in Asian and Caucasian patients, although the effect on HOMA-β was inferior in Asian patients. The effect of DPP-4 inhibitors on HOMA-IR and body weight in Asian patients was comparable with that observed in Caucasian patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Utility of Saxagliptin in the Treatment of Type 2 Diabetes: Review of Efficacy and Safety

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a complex disease in which multiple organs and hormones contribute to the pathogenesis of disease. The intestinal hormone, glucagon-like peptide-1 (GLP-1), secreted in response to nutrient ingestion, increases insulin secretion from pancreatic β-cells and reduces glucagon secretion from pancreatic α-cells. GLP-1 is inactivated by the dipeptidyl peptidase-4 (DPP-4) enzyme. Saxagliptin is a DPP-4 inhibitor that prevents the degradation of endogenous GLP-1 and prolongs its actions on insulin and glucagon secretion. This article reviews the efficacy and safety of saxagliptin in patients with T2DM.

METHODS

A PubMed literature search was conducted to identify relevant, peer-reviewed saxagliptin clinical trial articles published between January 2008 and June 2015. Search terms included "saxagliptin" and "DPP-4 inhibitors".

RESULTS

In clinical trials, saxagliptin significantly improved glycemic control when used as monotherapy or as add-on therapy to other antidiabetes agents and was associated with a low risk of hypoglycemia. In a large cardiovascular (CV) outcomes trial (SAVOR) in patients with T2DM and with established CV disease or multiple CV risk factors, saxagliptin neither increased nor decreased CV risk compared with placebo as assessed by the composite end point of death from CV causes, nonfatal myocardial infarction, or nonfatal stroke. Unexpectedly, more patients in the saxagliptin (3.5%) than in the placebo group (2.8%) were hospitalized for heart failure.

CONCLUSION

Saxagliptin demonstrated statistically significant and clinically meaningful improvements in glycemic control and a low risk of hypoglycemia in patients with T2DM. However, this positive profile needs to be tempered by the observation of an increased risk of hospitalization for heart failure in the SAVOR trial. Results from ongoing CV outcome trials with other DPP-4 inhibitors may provide additional data on how best to manage patients with T2DM who are at risk for heart failure.

FUNDING

AstraZeneca LP.

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.

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

AIMS

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

METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

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

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

Saxagliptin efficacy and safety in patients with type 2 diabetes receiving concomitant statin therapy

AIMS

To examine whether concomitant statin therapy affects glycemic control with saxagliptin 2.5 and 5mg/d in patients with type 2 diabetes mellitus (T2DM).

METHODS

Efficacy and safety were analyzed post hoc for pooled data from 9 saxagliptin randomized, placebo-controlled trials with a primary 24-week treatment period (4 monotherapy, 2 add-on to metformin, 1 each add-on to a sulfonylurea, thiazolidinedione, or insulin±metformin). Safety was also assessed in an 11-study, 24-week pool and an extended 20-study pool, which included 9 additional 4- to 52-week randomized studies. Comparisons were performed for patient groups defined by baseline statin use.

RESULTS

Saxagliptin produced greater mean reductions in glycated hemoglobin than placebo, with no interaction between treatment and baseline statin use (P=0.47). In patients receiving saxagliptin 2.5 and 5mg and placebo, the proportion of patients with ≥1 adverse event (AE) was 78.1%, 64.0%, and 63.2%, respectively, in patients with any statin use and 70.6%, 57.9%, and 55.0% in patients with no statin use. Serious AEs, deaths, and symptomatic confirmed hypoglycemia (fingerstick glucose ≤50mg/dL) were few and similar, irrespective of baseline statin use.

CONCLUSIONS

Saxagliptin improves glycemic control and is generally well tolerated in patients with T2DM, irrespective of concomitant statin therapy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A randomized controlled trial of the efficacy and safety of twice-daily saxagliptin plus metformin combination therapy in patients with type 2 diabetes and inadequate glycemic control on metformin monotherapy

BACKGROUND

To compare the safety and efficacy of saxagliptin 2.5 mg twice daily (BID) versus placebo add-on therapy to metformin immediate release (IR) in patients with type 2 diabetes and inadequate glycemic control with metformin alone.

METHODS

This multicenter, 12-week, double-blind, parallel-group trial enrolled adult outpatients with type 2 diabetes (glycated hemoglobin [HbA1c] 7.0%-10.0%) on stable metformin IR monotherapy (≥1500 mg, BID for ≥8 weeks). Patients were randomized to double-blind saxagliptin 2.5 mg BID or placebo added on to metformin IR following a 2-week, single-blind, placebo add-on therapy lead-in period. The primary end point was the change from baseline to week 12 in HbA1c. Key secondary end points included change from baseline to week 12 in fasting plasma glucose (FPG) and the proportion of patients achieving HbA1c <7.0% or HbA1c ≤ 6.5% at week 12. Efficacy was analyzed in all patients who received randomized study drug with ≥1 postbaseline assessment. Safety was assessed in all treated patients.

RESULTS

In total, 74 patients were randomized to double-blind saxagliptin add-on therapy and 86 to placebo add-on therapy. At week 12, least-squares mean changes (95% CI) from baseline HbA1c (adjusted for baseline HbA1c) were significantly greater (P = 0.006) in the saxagliptin + metformin group -0.56% (-0.74% to -0.38%) versus the placebo + metformin group -0.22% (-0.39% to -0.06%). Adjusted mean changes from baseline in FPG were numerically greater with saxagliptin versus placebo; the difference (95% CI) -9.5 mg/dL (-21.7 to 2.7) was not statistically significant (P = 0.12). A numerically greater proportion of patients in the saxagliptin group than the placebo group achieved HbA1c < 7.0% (37.5% vs 24.2%) or HbA1c ≤6.5% (24.6% vs 10.7%). There were no unexpected safety findings. Hypoglycemia occurred in 4 patients (5.4%) in the saxagliptin group and 1 patient (1.2%) in the placebo group; confirmed hypoglycemia (symptoms plus fingerstick glucose ≤50 mg/dL) occurred in 1 patient in the placebo group.

CONCLUSIONS

Addition of saxagliptin 2.5 mg BID to metformin therapy in patients with type 2 diabetes and inadequate glycemic control on metformin monotherapy reduced HbA1c compared with placebo added to metformin, with an adverse events profile similar to placebo and no unexpected safety findings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00885378.

Assessment of the cardiovascular safety of saxagliptin in patients with type 2 diabetes mellitus: pooled analysis of 20 clinical trials

BACKGROUND

It is important to establish the cardiovascular (CV) safety profile of novel antidiabetic drugs.

METHODS

Pooled analyses were performed of 20 randomized controlled studies (N = 9156) of saxagliptin as monotherapy or add-on therapy in patients with type 2 diabetes mellitus (T2DM) as well as a subset of 11 saxagliptin + metformin studies. Adjudicated major adverse CV events (MACE; CV death, myocardial infarction [MI], and stroke) and investigator-reported heart failure were assessed, and incidence rates (IRs; events/100 patient-years) and IR ratios (IRRs; saxagliptin/control) were calculated (Mantel-Haenszel method).

RESULTS

In pooled datasets, the IR point estimates for MACE and individual components of CV death, MI, and stroke favored saxagliptin, but the 95% CI included 1. IRR (95% CI) for MACE in the 20-study pool was 0.74 (0.45, 1.25). The Cox proportional hazard ratio (95% CI) was 0.75 (0.46, 1.21), suggesting no increased risk of MACE in the 20-study pool. In the 11-study saxagliptin + metformin pool, the IRR for MACE was 0.93 (0.44, 1.99). In the 20-study pool, the IRR for heart failure was 0.55 (0.27, 1.12).

CONCLUSIONS

Analysis of pooled data from 20 clinical trials in patients with T2DM suggests that saxagliptin is not associated with an increased CV risk.

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

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

Clinical utility in the treatment of type 2 diabetes with the saxagliptin/metformin fixed combination

Fixed-dose combination (FDC) products represent a widely accepted approach to type 2 diabetes treatment, given that monotherapies sometimes fail to meet the treatment targets - obtaining a sustained reduction in micro- and macrovascular complications. Saxagliptin (SAXA)/metformin (MET) FDC tablets can be used either alone or in combination with glyburide, thiazolidinediones, or insulin. It has been proven that the SAXA/MET combination leads to a significant improvement in glycemic control compared to placebo in patients with type 2 diabetes that is inadequately controlled with MET alone. In addition, this FDC has been proven to be safe for people with diabetes mellitus and established cardiovascular disease, elderly patients, and patients with impaired renal function (>30 mL/minute), with dosage modification. Patient compliance, adherence, and persistence to the therapeutic regimen has been shown to be very good, while the titration of each compound according to the patient's profile is easy, given the availability of different formulations. The SAXA/MET FDC is a patient-friendly, dosage-flexible, and hypoglycemia-safe regimen with very few adverse events and a neutral or even favorable effect on body weight. It achieves significant glycosylated hemoglobin A1c reduction helping the patient to achieve his/her individual glycemic goals.