The dipeptidyl peptidase (DPP)-4 inhibitors for type 2 diabetes mellitus in challenging patient groups

Using DPP-4 inhibitors to modulate beta cell function in type 1 diabetes and in the treatment of diabetic kidney disease

INTRODUCTION

DPP-4 inhibitors have pleomorphic effects that extend beyond the anti-hyperglycemic labeled use of the drug. DPP-4 inhibitors have demonstrated promising renal protective effects in T2DM and T1DM and protective effects against immune destruction of pancreatic beta-cells in T1DM.

AREAS COVERED

The efficacy of DPP-4 inhibitors in the treatment of diabetic kidney disease and possible adjunct with insulin in the treatment of T1DM to preserve beta-cell function. Pertinent literature was identified through Medline, PubMed and ClinicalTrials.gov (1997-November 2018) using the search terms T1DM, sitagliptin, vildagliptin, linagliptin, beta-cell function, diabetic nephropathy. Only articles are written in the English language, and clinical trials evaluating human subjects were used.

EXPERT OPINION

DPP-4 inhibitors can be used safely in patients with diabetic kidney disease and do not appear to exacerbate existing diabetic nephropathy. Linagliptin reduces albuminuria and protects renal endothelium from the deleterious effects of hyperglycemia. The effects of DPP-4 inhibitors on preserving beta-cell function in certain subtypes of T1DM [e.g. Latent Autoimmune Diabetes in Adult (LADA) and Slowly Progressive Type 1 Diabetes (SPIDDM)] are encouraging and show promise.

Understanding the Gap Between Efficacy in Randomized Controlled Trials and Effectiveness in Real-World Use of GLP-1 RA and DPP-4 Therapies in Patients With Type 2 Diabetes

OBJECTIVE

The objective of this study was to estimate and explain the gap between clinical efficacy and real-world (RW) effectiveness of type 2 diabetes medications.

RESEARCH DESIGN AND METHODS

This mixed-methods quasi-experimental study used retrospective claims (Optum/Humedica) to compare the change in HbA_1c of RW patients with type 2 diabetes 12 months after starting a glucagon-like peptide 1 receptor agonist (GLP-1 RA) or dipeptidyl peptidase 4 (DPP-4) inhibitor with published findings from randomized controlled trials (RCTs) evaluating these drugs. Selected RW patients were similar to RCT patients, and regression analysis was used in the RW data to adjust for differences between poorly adherent and adherent patients to explain why RCT and RW findings may differ.

RESULTS

RW patients initiating a GLP-1 RA (n = 221) or a DPP-4 (n = 652) experienced smaller reductions in HbA_1c (GLP-1 RA: -0.52% [-6 mmol/mol], DPP-4: -0.51% [-6 mmol/mol])than reported in RCTs (-1.30% [-14 mmol/mol] from seven GLP-1 RA RCTs, n = 2,600; -0.68% [-8 mmol/mol] from four DPP-4 RCTs, n = 1,889). Baseline HbA_1c, additional medications, and adherence were significant explanatory factors in the RW HbA_1c change. Modeled estimates of RCT efficacy (-1.04% GLP-1 RA [-12 mmol/mol], -0.69% DPP-4 [-8 mmol/mol]) were within the RCTs' reported range (GLP-1 RA: -0.84% to -1.60% [-9 to -18 mmol/mol], DPP-4: -0.47% to -0.90% [-5 to -10 mmol/mol]). Poor medication adherence accounted for approximately three-fourths of the gap between RW and expected RCT results (gap = 0.51% [6 mmol/mol] GLP-1 RA; 0.18% [3 mmol/mol] DPP-4).

CONCLUSIONS

Poor medication adherence is primarily why RW effectiveness is significantly less than RCT efficacy, suggesting an urgent need to effectively address adherence among patients with type 2 diabetes.

Short-term, high-fat overfeeding impairs glycaemic control but does not alter gut hormone responses to a mixed meal tolerance test in healthy, normal-weight individuals

Obesity is undoubtedly caused by a chronic positive energy balance. However, the early metabolic and hormonal responses to overeating are poorly described. This study determined glycaemic control and selected gut hormone responses to nutrient intake before and after 7 d of high-fat overfeeding. Nine healthy individuals (five males, four females) performed a mixed meal tolerance test (MTT) before and after consuming a high-fat (65 %), high-energy (+50 %) diet for 7 d. Measurements of plasma glucose, NEFA, acylated ghrelin, glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and serum insulin were taken before (fasting) and at 30-min intervals throughout the 180-min MTT (postprandial). Body mass increased by 0·79 (sem 0·14) kg after high-fat overfeeding (P<0·0001), and BMI increased by 0·27 (sem 0·05) kg/m2 (P=0·002). High-fat overfeeding also resulted in an 11·6 % increase in postprandial glucose AUC (P=0·007) and a 25·9 % increase in postprandial insulin AUC (P=0·005). Acylated ghrelin, GLP-1 and GIP responses to the MTT were all unaffected by the high-fat, high-energy diet. These findings demonstrate that even brief periods of overeating are sufficient to disrupt glycaemic control. However, as the postprandial orexigenic (ghrelin) and anorexigenic/insulintropic (GLP-1 and GIP) hormone responses were unaffected by the diet intervention, it appears that these hormones are resistant to short-term changes in energy balance, and that they do not play a role in the rapid reduction in glycaemic control.

Pharmacokinetic and pharmacodynamic interactions between metformin and a novel dipeptidyl peptidase-4 inhibitor, evogliptin, in healthy subjects

Evogliptin is a newly developed dipeptidyl peptidase-4 (DPP-4) inhibitor, which is expected to be combined with metformin for treating type 2 diabetes mellitus. We investigated the potential pharmacokinetic and pharmacodynamic interactions between evogliptin and metformin. A randomized, open-label, multiple-dose, six-sequence, three-period crossover study was conducted in 36 healthy male subjects. All subjects received three treatments, separated by 7-day washout intervals: evogliptin, 5 mg od for 7 days (EVO); metformin IR, 1,000 mg bid for 7 days (MET); and the combination of EVO and MET (EVO + MET). After the last dose in a period, serial blood samples were collected for 24 hours for pharmacokinetic assessments. During steady state, serial blood samples were collected for 2 hours after an oral glucose tolerance test, and DPP-4, active glucagon-like peptide-1, glucose, glucagon, insulin, and C-peptide were measured to assess pharmacodynamic properties. EVO + MET and EVO showed similar steady state maximum concentration and area under the concentration-time curve at steady state values for evogliptin; the geometric mean ratios (90% confidence interval) were 1.06 (1.01-1.12) and 1.02 (0.99-1.06), respectively. EVO + MET slightly reduced steady state maximum concentration and area under the concentration-time curve at steady state values for metformin compared to MET, with geometric mean ratios (90% confidence interval) of 0.84 (0.79-0.89) and 0.94 (0.89-0.98), respectively. EVO + MET and EVO had similar DPP-4 inhibition efficacy, but EVO + MET increased active glucagon-like peptide-1 and reduced glucose to larger extents than either EVO or MET alone. Our results suggested that EVO+MET could provide therapeutic benefits without clinically significant pharmacokinetic interactions. Thus, the EVO + MET combination is a promising option for treating type 2 diabetes mellitus.

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

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

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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