Efficacy and safety of linagliptin 2.5 mg twice daily versus 5 mg once daily in patients with type 2 diabetes inadequately controlled on metformin: a randomised, double-blind, placebo-controlled trial

Safety of Linagliptin in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Clinical Trials

BACKGROUND

Linagliptin is an oral dipeptidyl peptidase DPP-4 inhibitor, which is indicated for the treatment of Type 2 diabetes mellitus (T2DM) as monotherapy or add-on to therapy with other hypoglycemic drugs.

OBJECTIVES

We aimed to summarize the evidence from randomized controlled trials (RCTs) to assess the safety of linagliptin focusing on cardiovascular risks among subjects with type 2 diabetes mellitus.

METHODS

We conducted a systematic search across the following databases: Medline, Embase, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov from inception to November 2021. Randomized controlled trials (RCTs) of linagliptin compared to placebo in patients with Type 2 diabetes were included. The primary safety points were cardiovascular (CV) adverse events including non-fatal stroke, non-fatal myocardial infarction (MI), CV death, MI, stroke, and hospitalization for unstable angina. While, secondary safety points included 17 reported adverse events such as infections, hypoglycemia and abdominal pain. Three reviewers independently screened and reviewed each study to extract relevant information. Any discrepancies were resolved by consensus. We conducted a meta-analysis using the random effects model. Pooled risk ratios (RRs) of targeted adverse events with linagliptin compared to placebo were estimated using the Mantel-Haenszel test.

RESULTS

A total of 24 studies with 19,981 adult patients were included. There was no difference in the incidence of all CV adverse events or individual CV adverse events between linagliptin and the placebo arms. The pooled estimate of the risk of upper respiratory tract infection was reported in twelve trials with a 38% risk reduction among patients treated with the linagliptin group compared to the placebo group (RR = 0.62, 95% CI: 0.45-0.85, and I2 = 0%), while no difference was found in other infections. For gastrointestinal disorders, the risk of abdominal pain showed a 65% risk reduction among patients treated with the linagliptin group compared to the placebo group (RR = 0.35, 95% CI: 0.16-0.77, and I2 = 0%).

CONCLUSION

Our study showed an overall acceptable safety profile of linagliptin in patients with T2DM. Moreover, our study showed a risk reduction of upper respiratory tract infection and abdominal pain when using linagliptin compared to placebo.

Safety and tolerability of linagliptin in Asians with type 2 diabetes: a pooled analysis of 4457 patients from 21 randomized, double-blind, placebo-controlled clinical trials

BACKGROUND

Safety and tolerability of glucose-lowering drugs is a key consideration for use in type 2 diabetes (T2D). We evaluated the safety and tolerability of the dipeptidyl peptidase-4 inhibitor linagliptin in Asian patients with T2D.

RESEARCH DESIGN AND METHODS

This was a post-hoc, descriptive pooled analysis of 21 randomized, double-blind, placebo-controlled clinical trials of linagliptin in T2D patients lasting ≤52 weeks. We evaluated adverse events (AEs) and laboratory parameters in Asian participants living in Asia, both overall and in the East Asian subgroup.

RESULTS

This analysis included 4457 Asian patients overall (2712 receiving linagliptin; 1745 receiving placebo) and 3057 (68.6%) East Asians. AEs were reported in 1510 (55.7%) Asian patients receiving linagliptin and 1032 (59.1%) receiving placebo but were considered drug-related in only 13.0% of each group. Serious AEs occurred in 109 (4.0%) linagliptin patients and 90 (5.2%) placebo patients. The most common AEs were nasopharyngitis (6.4% linagliptin, 7.3% placebo), upper respiratory tract infection (5.7% linagliptin, 6.5% placebo), and hypoglycemia (7.3% linagliptin, 6.3% placebo). One linagliptin patient had pancreatitis; none had bullous pemphigoid. No clinically relevant mean changes in laboratory parameters occurred. These findings were consistent in East Asians.

CONCLUSIONS

Linagliptin is well tolerated in Asian T2D patients, including East Asians, with low risk for AEs.

Incretin mimetics and sodium-glucose co-transporter 2 inhibitors as monotherapy or add-on to metformin for treatment of type 2 diabetes: a systematic review and network meta-analysis

PURPOSE

Although there are many different methods of treating type 2 diabetes (T2D), it is still difficult to draw coincident conclusions concerning the efficacy and safety of different classes of new drugs, and the recommendation level of them has still kept uncertain as second anti-diabetic agents. Therefore, the aim of this study was to summarize evidence on the efficacy and safety of DPP-4is, GLP-1RAs and SGLT-2is as monotherapy or add-on to metformin (Met) for treatment of T2D.

MATERIALS AND METHODS

We searched PubMed, Embase, Cochrane library and ClinicalTrials.gov for relevant articles in keeping with established methods using terms associated with anti-diabetic agents up to February, 2020, with no start date restriction. Weighted mean difference and risk ratios with 95% confidence intervals were calculated within traditional and network meta-analysis. Primary outcomes were the mean change in hemoglobin A1c (HbA1c), fasting plasma glucose (FPG) change and the frequency of hypoglycemic events from baseline after 12 weeks of treatment.

RESULTS

In total, 64 eligible studies comprising 37,780 patients and 7 treatment strategies were included. The results of primary outcomes showed that GLP-1RAs were significantly more effective than DPP-4is or SGLT-2is in reducing HbA1c when add-on to Met. For FPG, both GLP-1RAs and SGLT-2is significantly reduced FPG compared with DPP-4is whether add-on to Met or not. For hypoglycemia, monotherapy has a lower risk than combination therapy except for SGLT-2is. Ranking probability analysis indicated that GLP-1RAs and SGLT-2is, respectively, reduced HbA1c and FPG most when add-on to Met. Meanwhile, GLP-1RAs took the lowest risk to induce the hypoglycemia, whereas GLP-1RAs plus Met the highest.

CONCLUSIONS

Both GLP-1RAs and SGLT-2is have their own advantages in efficacy and safety. Monotherapy is beneficial for reducing the risk of hypoglycemia. The recommendation should be a patient-centered approach when selecting treatment choices.

Sensitive Simultaneous Measurement of Metformin and Linagliptin in Plasma Samples by Couple of Nano Graphene Oxide-based Dispersive Solid Phase Extraction Method and Liquid Chromatography

A simple, rapid, and ultra sensitive dispersive solid phase extraction based on nano graphene oxide was developed for simultaneous measurement of trace amounts of metformin (MET) and linagliptin (LIN) in plasma samples by HPLC-UV-Vis. Affecting factors on the extraction of these drugs, including adsorbent weight, extraction time, organic solvent type, desorption situations, and composition of solvent were examined and optimized. In optimum conditions, the LOD (limit of detection) and LOQ (limit of quantification) of the suggested technique were 2.0 ngmL^-1 and 6.1 (ngmL^-1) for LIN and 3.0 ngmL^-1 and 9.2 ngmL^-1 for MET, respectively. Suitable linear behavior in the considered ranges of concentration (10-2000 ngmL^-1) and good correlation coefficient of 0.9901 and 0.9903 (r²) for LIN and MET were obtained, respectively. The RSD (relative standard deviations) according to three replicate measurements at 2, 20, 200 ngmL^-1 levels of these drugs was less than 8.0%. In the last step, applicability of the suggested technique was examined by analyzing the drugs in plasma samples and reasonable results were achieved.

Age, sex, disease severity, and disease duration difference in placebo response: implications from a meta-analysis of diabetes mellitus

BACKGROUND

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

METHODS

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

RESULTS

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

CONCLUSION

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Formulation development of linagliptin solid lipid nanoparticles for oral bioavailability enhancement: role of P-gp inhibition

Linagliptin (LGP), a novel anti-diabetic drug, is a DPP-4 inhibitor used in the treatment of type II diabetes. One of the major disadvantages of LGP is its low oral bioavailability (29.5%) due to first-pass metabolism and P-gp efflux. In an attempt to increase the oral bioavailability, LGP solid lipid nanoparticles (LGP-SLNs) were developed with poloxamer 188 and Tween 80 as P-gp inhibitors. LGP-SLNs were formulated using palmitic acid, poloxamer 188 and Tween 80 as lipid, surfactant and co-surfactant, respectively, by hot homogenization ultrasonication method and optimized using 3² full factorial designs. Particle size, entrapment efficiency (%EE) and drug release at 24 h were evaluated as responses. An optimized batch of LGP-SLNs (L12) was evaluated for intestinal transport of LGP by conducting in situ single-pass intestinal perfusion (SPIP), everted gut sac and Caco-2 permeability study. The pharmacokinetic and pharmacodynamic evaluation of L12 was carried out in albino Wistar rats. The mean particle size, polydispersity index, zeta potential and %EE of L12 were found to be 225.96 ± 2.8 nm, 0.180 ± 0.034, - 5.4 ± 1.07 mV and 73.8 ± 1.73%, respectively. %CDR of 80.96 ± 3.13% was observed in 24 h. The permeability values of LGP-SLNs in the absorptive direction were 1.82-, 1.76- and 1.74-folds higher than LGP-solution (LGP-SOL) in SPIP, everted gut sac and Caco-2 permeability studies, respectively. LGP-SLNs exhibited relative bioavailability of 300% and better reduction in glucose levels in comparison with LGP-SOL in rats. The enhanced oral bioavailability exhibited by LGP-SLNs bioavailability may be due to P-gp efflux inhibition and lymphatic targeting. Improved bioabsorption can cause reduction in dose, dose-related side effects and frequency of administration. Thus, LGP-SLNs can be considered promising carriers for oral delivery but clinical studies are required to confirm the proof of concept.Graphical abstract.

Early Combination Therapy with Linagliptin and Metformin in People with Type 2 Diabetes Improves Glycemic Control to HbA1c ≤ 6.5% without Increasing Hypoglycemia: Pooled Analysis of Two Randomized Clinical Trials

INTRODUCTION

Clinical guidelines suggest a glycated hemoglobin A1c (HbA1c) target of ≤ 6.5% for type 2 diabetes patients with short duration of disease, few comorbidities and/or long life expectancy-provided this goal can be achieved safely. We explored whether initial combination treatment with the dipeptidyl peptidase-4 inhibitor linagliptin and metformin could provide better glycemic control (HbA1c ≤ 6.5%) than metformin alone without increasing hypoglycemia.

METHODS

We pooled and analyzed individual patient data from two randomized clinical trials of early combination therapy with linagliptin and metformin versus metformin monotherapy. The primary outcome in both trials was the change in HbA1c from baseline to week 24. We evaluated the percentage of patients who achieved HbA1c ≤ 6.5% at week 24 and the incidence of adverse events.

RESULTS

Most (> 70%) of the 1160 patients analyzed were treatment naive, and more than half had had diabetes for ≤ 1 year; mean baseline HbA1c was approximately 8.7%. Combination therapy with linagliptin and metformin resulted in more patients achieving HbA1c ≤ 6.5% than metformin alone, both for a metformin dose of 500 mg (40.1 vs. 22.9%, respectively, odds ratio [OR] 2.84, 95% confidence interval [CI] 1.87-4.32) and 1000 mg (49.5 vs. 35.4%, respectively, OR 2.28, 95% CI 1.54-3.40). Hypoglycemia occurred in < 3% of patients, with a comparable incidence between treatment groups. Other adverse events were also balanced between groups.

CONCLUSION

Early combination treatment with linagliptin and metformin can improve the chances of achieving tight glycemic control (HbA1c ≤ 6.5%) without increasing the risk of hypoglycemia or other adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00798161 and NCT01708902.

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.

Risk of any hypoglycaemia with newer antihyperglycaemic agents in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVES

For patients with type 2 diabetes, newer antihyperglycaemic agents (AHA), including the dipeptidyl peptidase IV inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA) and sodium glucose co-transporter 2 inhibitors (SGLT2i) offer a lower risk of hypoglycaemia relative to sulfonylurea or insulin. However, it is not clear how AHA compare to placebo on risk of any hypoglycaemia. This study evaluates the risk of any and severe hypoglycaemia with AHA and metformin relative to placebo.

DESIGN

A systematic review and meta-analysis was conducted of randomized, placebo-controlled trials ≥12 weeks in duration. MEDLINE, Embase and the Cochrane Library were searched up to April 16, 2019. Studies allowing use of other diabetes medications were excluded. Mantel-Haenszel risk ratio with 95% confidence intervals were used to pool estimates based on class of AHA and number of concomitant therapies used.

PATIENTS

Eligible studies enrolled patients with type 2 diabetes ≥18 years of age.

RESULTS

144 studies met our inclusion criteria. Any hypoglycaemia was not increased with AHA when used as monotherapy (DPP4i (RR 1.12; 95% CI 0.81-1.56), GLP1RA (1.77; 0.91-3.46), SGLT2i (1.34; 0.83-2.15)), or as add-on to metformin (DPP4i (0.95; 0.67-1.35), GLP1RA (1.24; 0.80-1.91), SGLT2i (1.29; 0.91-1.83)) or as triple therapy (1.13; 0.67-1.91). However, metformin monotherapy (1.73; 1.02-2.94) and dual therapy initiation (3.56; 1.79-7.10) was associated with an increased risk of any hypoglycaemia. Severe hypoglycaemia was rare not increased for any comparisons.

CONCLUSIONS

Metformin and the simultaneous initiation of dual therapy, but not AHA used alone or as single add-on combination therapy, was associated with an increased risk of any hypoglycaemia relative to placebo.

Comparison of Power, Prognosis, and Extrapolation Properties of Four Population Pharmacodynamic Models of HbA1c for Type 2 Diabetes

Reusing published models saves time; time to be used for informing decisions in drug development. In antihyperglycemic drug development, several published HbA1c models are available but selecting the appropriate model for a particular purpose is challenging. This study aims at helping selection by investigating four HbA1c models, specifically the ability to identify drug effects (shape, site of action, and power) and simulation properties. All models could identify glucose effect nonlinearities, although for detecting the site of action, a mechanistic glucose model was needed. Power was highest for models using mean plasma glucose to drive HbA1c formation. Insulin contribution to power varied greatly depending on the drug target; it was beneficial only if the drug target was insulin secretion. All investigated models showed good simulation properties. However, extrapolation with the mechanistic model beyond 12 weeks resulted in drug effect overprediction. This investigation aids drug development in decisions regarding model choice if reusing published HbA1c models.

Linagliptin versus sitagliptin in patients with type 2 diabetes mellitus: a network meta-analysis of randomized clinical trials

Background

Diabetes is one of the most common chronic and costly diseases worldwide and type 2 diabetes is the most common type which accounts for about 90% of cases with diabetes. New medication-therapy regimens such as those containing linagliptin alone or in combination with other medications (within the category of DDP-4 inhibitors) must be evaluated in terms of efficacy and compared with other currently used drugs and then enter the medication list of the country. Hence, this study aimed to compare the clinical efficacy of the two drugs, i.e. linagliptin and sitagliptin, in patients with type 2 diabetes.

Methods

A systematic review was conducted to identify all clinical trials published by 2015 which compared the two drugs in patients with type 2 diabetes. Using keywords such as “linagliptin”, “type 2 diabetes mellitus”, “sitagliptin” and related combinations, we searched databases including Scopus, PubMed, and Web of Science. The quality of the selected studies was evaluated using the Jadad score. Considering primary and secondary outcomes extracted from the reviewed studies, a network meta-analysis was used to conduct a systematic comparison between the two studied drugs.

Results

This network meta-analysis included 32 studies (Linagliptin vs PLB: n = 8, Sitagliptin vs PLB: n = 13, Linagliptin + MET vs PLB + MET: n = 4, and Sitagliptin + MET vs PLB + MET: n = 7) and a total of 13,747 patients. The results showed no significant difference between linagliptin and sitagliptin in terms of key efficacy and safety outcomes such as HbA1c changes from baseline, body weight change from baseline, percentage of patients achieving HbA1c <7, and percentage of patients experiencing hypoglycemic events (p > 0.05). The results showed that the efficacy of the two drug regimens was the same.

Conclusions

Based on the results, there was no significant difference between the two drugs, i.e. linagliptin and sitagliptin, in terms of efficacy; in other words, the efficacy of the two drugs was the same. Therefore, the use of these two drugs depends on their availability and cost.

Graphical abstract

Graphical abstract of the network meta-analysis performed to evaluate the alternatives under the study.

Electronic supplementary material

The online version of this article (10.1186/s40199-017-0189-6) contains supplementary material, which is available to authorized users.

Efficacy and Safety of Linagliptin in 2681 Asian Patients Stratified by Age, Obesity, and Renal Function: A Pooled Analysis of Randomized Clinical Trials

Introduction

Asian patients with type 2 diabetes (T2D) are younger, leaner, and more likely to develop renal dysfunction than White populations. In this multiethnic analysis of data from phase 3 trials, we investigated the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in Asians stratified by these subphenotypes.

Methods

Data from randomized, double-blind, placebo-controlled trials evaluating linagliptin (as monotherapy, add-on therapy to metformin ± sulfonylurea, combined with pioglitazone or added to insulin) were pooled with efficacy data from 11 randomized trials of at least 24 weeks and safety data from 15 trials of various durations.

Results

In the efficacy set, 1404 Asian patients received linagliptin [mean (standard deviation) age 54.5 (10.1) years; body mass index (BMI) 26.0 (3.9) kg/m²] and 661 received placebo [age 55.0 (9.7) years; BMI 26.1 (3.9) kg/m²] with the same glycated hemoglobin (HbA1c): 8.2 (0.9)% in both groups. At 24 weeks, the placebo-corrected adjusted mean ± standard error change from baseline in HbA1c with linagliptin was −0.73 ± 0.04% (95% confidence interval −0.81, −0.65; P < 0.0001). Reductions in HbA1c were similar upon stratification by age [<65 years, −0.71 ± 0.05% (−0.80, −0.62; P < 0.0001); ≥65 years, −0.81 ± 0.10% (−1.01, −0.60; P < 0.0001)], BMI (<25 kg/m², −0.82 ± 0.06% [−0.94, −0.70; P < 0.0001]; ≥25 kg/m², −0.65 ± 0.06% [−0.76, −0.54; P < 0.0001]) and estimated glomerular filtration rate [<90 mL/min/1.73 m², −0.71 ± 0.06% (−0.82, −0.60; P < 0.0001); ≥90 mL/min/1.73 m², −0.75 ± 0.06% (−0.87, −0.64; P < 0.0001)]. In the safety set (linagliptin, n = 1842; placebo, n = 839), 52.2% and 54.6% of patients, respectively, experienced adverse events. The rates of drug-related adverse events were 10.9% in the linagliptin group and 10.4% in the placebo group. The respective rates of hypoglycemia were 8.3% and 9.5%, mainly among patients treated with sulfonylurea or insulin. Severe hypoglycemia was rare (<1.0% in either group).

Conclusion

Linagliptin effectively reduced hyperglycemia in Asian patients with uncontrolled T2D, irrespective of age, BMI, renal function, or ethnic subgroups, and was well tolerated.

Funding

Boehringer Ingelheim, Eli Lilly and Company, and the Diabetes Alliance.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0595-7) contains supplementary material, which is available to authorized users.

Cardiovascular Safety of Dipeptidyl-Peptidase IV Inhibitors: A Meta-Analysis of Placebo-Controlled Randomized Trials

BACKGROUND

Large randomized trials have shown conflicting evidence regarding the cardiovascular safety of dipeptidyl-peptidase 4 (DPP-4) inhibitors. Systematic reviews have been limited by incomplete data and inclusion of observational studies. This study aimed to systematically evaluate the cardiovascular safety of DPP-4 inhibitors in patients with type 2 diabetes.

METHODS

Electronic databases were searched for randomized trials that compared DPP-4 inhibitors versus placebo and reported cardiovascular outcomes. The main outcome assessed in this analysis was heart failure. Other outcomes included all-cause mortality, cardiovascular mortality, myocardial infarction, and ischemic stroke. Summary odds ratios (ORs) were primarily constructed using Peto's model.

RESULTS

A total of 90 trials with 66,730 patients were included. Compared with placebo, DPP-4 inhibitors were associated with a non-significant increased risk of heart failure [OR 1.11, 95% confidence interval (CI) 0.99-1.25, P = 0.07] at a mean of 108 weeks. The risk of all-cause mortality (OR 1.03, 95% CI 0.94-1.12, P = 0.53), cardiovascular mortality (OR 1.02, 95% CI 0.92-1.14, P = 0.72), myocardial infarction (OR 0.98, 95% CI 0.88-1.09, P = 0.69), and ischemic stroke (OR 0.99, 95% CI 0.85-1.15, P = 0.92) was similar between both groups.

CONCLUSION

In patients with type 2 diabetes, the safety profile of DPP-4 inhibitors is similar to placebo. As a class, there is only weak evidence for an increased risk of heart failure.

Efficacy and safety of linagliptin in type 2 diabetes patients with self-reported hepatic disorders: A retrospective pooled analysis of 17 randomized, double-blind, placebo-controlled clinical trials

AIMS

Liver disease is highly prevalent among people with type 2 diabetes mellitus (T2DM). We evaluated the dipeptidyl peptidase-4 inhibitor linagliptin in subjects with T2DM and hepatic disorders.

METHODS

Data were pooled from 17 randomized, double-blind, placebo-controlled clinical trials of linagliptin in T2DM subjects that included individuals with self-reported history of hepatic disorders at baseline. The primary endpoint was change in HbA1c from baseline to week 24.

RESULTS

Of the 7009 participants (56% white, 39% Asian), 574 had hepatic disorders, most commonly hepatic steatosis (60%). At week 24, adjusted mean±standard error (SE) change in HbA1c from baseline in those with hepatic disorders was -0.75%±0.05 with linagliptin and -0.20%±0.08 with placebo [treatment difference: -0.54% (95% confidence interval-0.72 to -0.36); P<.0001]. There was no significant difference in HbA1c reduction between subjects with or without baseline hepatic disorders (P=.4042). Among subjects with hepatic disorders, 13.5% and 14.8% of the linagliptin and placebo groups, respectively, reported drug-related adverse events while 10.4% and 15.9%, respectively, reported hypoglycemia. Overall, adverse event rates were similar in individuals with or without hepatic disorders.

CONCLUSIONS

This large pooled analysis suggests that linagliptin is effective and well tolerated in people with T2DM and liver disease.

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.

Pharmacokinetic and pharmacodynamic evaluation of linagliptin for the treatment of type 2 diabetes mellitus, with consideration of Asian patient populations

Our aims were to summarize the clinical pharmacokinetics and pharmacodynamics of the dipeptidyl‐peptidase‐4 inhibitor, linagliptin, and to consider how these characteristics influence its clinical utility. Differences between linagliptin and other dipeptidyl‐peptidase‐4 inhibitors were also considered, in addition to the influence of Asian race on the pharmacology of linagliptin. Linagliptin has a xanthine‐based structure, a difference that might account for some of the pharmacological differences observed with linagliptin versus other dipeptidyl‐peptidase‐4 inhibitors. The long terminal half‐life of linagliptin results from its strong binding to dipeptidyl‐peptidase‐4. Despite this, linagliptin shows a short accumulation half‐life, as a result of saturable, high‐affinity binding to dipeptidyl‐peptidase‐4. The pharmacokinetic characteristics of linagliptin make it suitable for once‐daily dosing in a broad range of patients with type 2 diabetes mellitus. Unlike most other dipeptidyl‐peptidase‐4 inhibitors, linagliptin has a largely non‐renal excretion route, and dose adjustment is not required in patients with renal impairment. Furthermore, linagliptin exposure is not substantially altered in patients with hepatic impairment, and dose adjustment is not necessary for these patients. The 5‐mg dose is also suitable for patients of Asian ethnicity. Linagliptin shows unique pharmacological features within the dipeptidyl‐peptidase‐4 inhibitor class. Although most clinical trials of linagliptin have involved largely Caucasian populations, data on the pharmacokinetic/pharmacodynamic properties of linagliptin show that these features are not substantially altered in Asian populations. The 5‐mg dose of linagliptin is suitable for patients with type 2 diabetes mellitus irrespective of their ethnicity or the presence of renal or hepatic impairment.

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.

Cardiovascular Effect of Incretin-Based Therapy in Patients with Type 2 Diabetes Mellitus: Systematic Review and Meta-Analysis

BACKGROUND

To assess the cardiovascular (CV) risk associated with the use of incretin-based therapy in adult patients with type 2 diabetes mellitus (T2DM) primary prevention group with low CV risks.

METHODS

The clinical studies on incretin-based therapy published in medical journals until August 2014 were comprehensively searched using MEDLINE, EMBASE and CENTRAL with no language restriction. The studies were systemically reviewed and evaluated for CV risks using a meta-analysis approach and where they meet the following criteria: clinical trial, incidence of predefined CV disease, T2DM with no comorbidities, age > 18 years old, duration of at least 12 weeks, incretin-based therapy compared with other antihyperglycaemic agents or placebo. Statistical analyses were performed using a Mantel-Haenszel (M-H) test. The odds ratios (OR) and their 95% confidence interval (CI) were estimated and displayed for comparison.

RESULTS

A total of 75 studies comprising 45,648 patients with T2DM were selected. The pooled estimate demonstrated no significance in decreased CV risk with incretin-based therapy versus control (M-H OR, 0.90; 95% CI, 0.81-1.00).

CONCLUSIONS

This meta-analysis suggests that incretin-based therapy show no significant protective effect on CV events in T2DM primary prevention group with low CV risks. Prospective randomized controlled trials are required to confirm the results of this analysis.

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.

Comparative efficacy and safety of antidiabetic drug regimens added to metformin monotherapy in patients with type 2 diabetes: a network meta-analysis

Introduction

When first line therapy with metformin is insufficient for patients with type 2 diabetes (T2D), the optimal adjunctive therapy is unclear. We assessed the efficacy and safety of adjunctive antidiabetic agents in patients with inadequately controlled T2D on metformin alone.

Materials and Methods

A search of MEDLINE and CENTRAL, clinicaltrials.gov, regulatory websites was performed. We included randomized controlled trials of 3–12 months duration, evaluating Food and Drug Administration or European Union approved agents (noninsulin and long acting, once daily basal insulins) in patients experiencing inadequate glycemic control with metformin monotherapy (≥1500 mg daily or maximally tolerated dose for ≥4 weeks). Random-effects network meta-analyses were used to compare the weighted mean difference for changes from baseline in HbA1c, body weight (BW) and systolic blood pressure (SBP), and the risk of developing hypoglycemia, urinary (UTI) and genital tract infection (GTI).

Results

Sixty-two trials evaluating 25 agents were included. All agents significantly reduced HbA1c vs. placebo; albeit not to the same extent (range, 0.43% for miglitol to 1.29% for glibenclamide). Glargine, sulfonylureas (SUs) and nateglinide were associated with increased hypoglycemia risk vs. placebo (range, 4.00–11.67). Sodium glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 analogs, miglitol and empagliflozin/linagliptin significantly reduced BW (range, 1.15–2.26kg) whereas SUs, thiazolindinediones, glargine and alogliptin/pioglitazone caused weight gain (range, 1.19–2.44kg). SGLT2 inhibitors, empagliflozin/linagliptin, liraglutide and sitagliptin decreased SBP (range, 1.88–5.43mmHg). No therapy increased UTI risk vs. placebo; however, SGLT2 inhibitors were associated with an increased risk of GTI (range, 2.16–8.03).

Conclusions

Adding different AHAs to metformin was associated with varying effects on HbA1c, BW, SBP, hypoglycemia, UTI and GTI which should impact clinician choice when selecting adjunctive therapy.

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

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

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

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

OBJECTIVE

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

DESIGN

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

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

DATA EXTRACTION AND ANALYSIS

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

RESULTS

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

CONCLUSIONS

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

Linagliptin: from bench to bedside

PURPOSE

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

SUMMARY

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

CONCLUSION

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

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

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

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

OBJECTIVE

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

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

RESULTS

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

CONCLUSIONS

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

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

A novel model-based meta-analysis to indirectly estimate the comparative efficacy of two medications: an example using DPP-4 inhibitors, sitagliptin and linagliptin, in treatment of type 2 diabetes mellitus

OBJECTIVES

To develop a longitudinal statistical model to indirectly estimate the comparative efficacies of two drugs, using model-based meta-analysis (MBMA). Comparison of two oral dipeptidyl peptidase (DPP)-4 inhibitors, sitagliptin and linagliptin, for type 2 diabetes mellitus (T2DM) treatment was used as an example.

DESIGN

Systematic review with MBMA.

DATA SOURCES

MEDLINE, EMBASE, http://www.ClinicalTrials.gov, Cochrane review of DPP-4 inhibitors for T2DM, sitagliptin trials on Food and Drug Administration website to December 2011 and linagliptin data from the manufacturer.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Double-blind, randomised controlled clinical trials, ≥12 weeks' duration, that analysed sitagliptin or linagliptin efficacies as changes in glycated haemoglobin (HbA1c) levels, in adults with T2DM and HbA1c >7%, irrespective of background medication. MODEL DEVELOPMENT AND APPLICATION: A Bayesian model was fitted (Markov Chain Monte Carlo method). The final model described HbA1c levels as function of time, dose, baseline HbA1c, washout status/duration and ethnicity. Other covariates showed no major impact on model parameters and were not included. For the indirect comparison, a population of 1000 patients was simulated from the model with a racial composition reflecting the average racial distribution of the linagliptin trials, and baseline HbA1c of 8%.

RESULTS

The model was developed using longitudinal data from 11 234 patients (10 linagliptin, 15 sitagliptin trials), and assessed by internal evaluation techniques, demonstrating that the model adequately described the observations. Simulations showed both linagliptin 5 mg and sitagliptin 100 mg reduced HbA1c by 0.81% (placebo-adjusted) at week 24. Credible intervals for participants without washout were -0.88 to -0.75 (linagliptin) and -0.89 to -0.73 (sitagliptin), and for those with washout, -0.91 to -0.76 (linagliptin) and -0.91 to -0.75 (sitagliptin).

CONCLUSIONS

This study demonstrates the use of longitudinal MBMA in the field of diabetes treatment. Based on an example evaluating HbA1c reduction with linagliptin versus sitagliptin, the model used seems a valid approach for indirect drug comparisons.

Clinical overview of linagliptin, a dipeptidyl peptidase-4 inhibitor, in patients with Type 2 diabetes mellitus

Linagliptin is a pharmacologically unique, orally active, once-daily dipeptidyl peptidase-4 inhibitor indicated for the treatment of hyperglycemia in patients with Type 2 diabetes mellitus. Compared with other dipeptidyl peptidase-4 inhibitors, linagliptin has a favorable pharmacokinetic profile with a primarily nonrenal route of elimination that avoids the need for dose adjustment in patients with renal impairment. When administered as monotherapy or in combination with other antihyperglycemic drugs, linagliptin treatment leads to clinically meaningful reductions in glycated hemoglobin, fasting plasma glucose and postprandial plasma glucose levels. In addition, pancreatic β-cell function is enhanced. Linagliptin treatment is well tolerated, with weight-neutral effects and no increased risk of hypoglycemia. Of note, linagliptin treatment was associated with a significantly reduced risk of cardiovascular events in clinical trials of ≤2 years, although this finding remains to be confirmed in larger and longer clinical outcomes studies.

Linagliptin/Metformin fixed-dose combination treatment: a dual attack to type 2 diabetes pathophysiology

Combination therapies are a widely accepted approach to type 2 diabetes treatment, considering that monotherapies fail to provide adequate glycemic control in the majority of cases. The combination of oral antidiabetic agents into a single tablet would significantly simplify the therapeutic regimen and maximize patients' adherence to treatment. Recently, a fixed-dose, single-tablet, combined formulation of linagliptin (a dipeptidyl peptidase-4 inhibitor) and metformin has been approved for use in type 2 diabetic patients, and is indicated as an adjunct to diet and exercise for those patients who remain inadequately controlled despite maximal tolerated doses of metformin, metformin and sulfonylurea, or linagliptin and metformin monotherapies. The combination tablet is administered twice daily and can be used either alone or combined with sulfonylureas. Clinical trials suggest that this fixed-dose combination provides significantly superior glycemic control compared to linagliptin and metformin monotherapy, in terms of improving key parameters of glucose homeostasis such as glycosylated hemoglobin, fasting and postprandial glucose levels. It also exhibits an excellent tolerability profile, without promoting weight gain and hypoglycemic episodes. The compounds of this formulation do not display clinically relevant pharmacokinetic interactions with each other, and exert synergistic (complementary) pharmacodynamic effects, including an enhanced incretin effect, suppressed hepatic glucose production, and improved peripheral insulin sensitivity. As a result, a linagliptin/metformin fixed-dose combination offers the potential to address multiple defects of type 2 diabetes pathophysiology (pancreatic islet dysfunction, insulin resistance, increased hepatic glucose output), and most importantly, in the context of a safe, efficacious, flexible, and convenient therapeutic regimen.

Initial combination of linagliptin and metformin improves glycaemic control in type 2 diabetes: a randomized, double-blind, placebo-controlled study

AIMS

To evaluate the efficacy and safety of initial combination therapy with linagliptin plus metformin versus linagliptin or metformin monotherapy in patients with type 2 diabetes.

METHODS

In this 24-week, double-blind, placebo-controlled, Phase III trial, 791 patients were randomized to one of six treatment arms. Two free combination therapy arms received linagliptin 2.5 mg twice daily (bid) + either low (500 mg) or high (1000 mg) dose metformin bid. Four monotherapy arms received linagliptin 5 mg once daily, metformin 500 mg or 1000 mg bid or placebo. Patients with haemoglobin A1c (HbA1c) ≥11.0% were not eligible for randomization and received open-label linagliptin + high-dose metformin.

RESULTS

The placebo-corrected mean (95% confidence interval) change in HbA1c from baseline (8.7%) to week 24 was -1.7% (-2.0, -1.4) for linagliptin + high-dose metformin, -1.3% (-1.6, -1.1) for linagliptin + low-dose metformin, -1.2% (-1.5, -0.9) for high-dose metformin, -0.8% (-1.0, -0.5) for low-dose metformin and -0.6 (-0.9, -0.3) for linagliptin (all p < 0.0001). In the open-label arm, the mean change in HbA1c from baseline (11.8%) was -3.7%. Hypoglycaemia occurred at a similar low rate with linagliptin + metformin (1.7%) as with metformin alone (2.4%). Adverse event rates were comparable across treatment arms. No clinically significant changes in body weight were noted.

CONCLUSIONS

Initial combination therapy with linagliptin plus metformin was superior to metformin monotherapy in improving glycaemic control, with a similar safety and tolerability profile, no weight gain and a low risk of hypoglycaemia.