Vildagliptin is a potent selective inhibitor of dipeptidyl peptidase-4 (DPP-4) that improves glycaemic control by increasing islet alpha-cell and beta-cell responsiveness to glucose. The worldwide clinical development program for omarigliptin, O-QWEST (Omarigliptin Q Weekly Efficacy and Safety in Type 2 Diabetes), includes 10 Phase 3 clinical trials involving approximately 8,000 patients with type 2 diabetes. Various classes of structurally different DPP IV inhibitors are currently being explored and few of them such as Sitagliptin and Vildagliptin were successfully launched. Several DPP-4 inhibitors have been developed and all of them have been shown to be efficient in improving glycemia with a low risk for adverse events. Selection of study group was as follows: 1. In adults, type 2 diabetes (previously called non–insulin–dependent diabetes mellitus or adult–onset diabetes; T2DM) accounts for about 90–95% of all diagnosed cases of diabetes. Linagliptin is a novel DPP-4 inhibitor that, in contrast to the other members of this drug class, is eliminated by a biliary/hepatic route rather than by renal elimination.
However, five articles reported data from open-label RCTs [36, 47–50]. The incidence of investigator-reported hypoglycaemia was 21.4% with linagliptin and 25.7% with placebo. Indirect measures show a possible improvement of beta-cell function. Two review authors (GXY and CYF) independently extracted the following data from each publication using a standardized form: publication data (title, first author, year and source of publication), study design, baseline characteristics of the study population (sample size, gender, age, duration of T2DM, BMI and HbA1c), description of the study drugs and the dosages, treatment duration, and primary outcome measures (changes from baseline to study endpoint for HbA1c). Research has demonstrated that DPP-4 inhibitors portray a very low risk of hypoglycemia development. Unfortunately, data was not available to allow a normality test; however, the switching threshold has been tested in one-way sensitivity analysis and was found not to change the conclusion over the cost-effectiveness of DAPA + MET over DPP-4i + MET. Lancet 2009; 373: 1765–1772.
Amgen has also filed the drug in the US, where it is expecting a decision by August 27, as well as in the EU. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: Richard D. Carr owns shares in Merck Inc., (known as MSD in Europe). This does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials. Editor-in-chief Kelly Close wrote about her experience using the GLP-1 agonist Victoza (liraglutide) off-label in our test drive, and she found that it improved her glucose control, reduced her insulin doses, and gave her hope for the potential of these drugs for type 1 diabetes. Van der Werf F, Armstrong P.
Many pre-clinical studies support this hypothesis and demonstrate that such combinatory strategies achieve strong synergy, both by enhancing and extending therapeutic success while minimizing toxic events as dose reduction of anti-CD3 is possible , . Introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, which block the aminopeptidase DPP-4 and subsequently prevent the degradation of the gut-derived incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), in immunotherapies makes sense as this class of orally-active agents not only improves β-cell function, possibly through β-cell protection and preservation , but also stimulates β-cell mass through β-cell replication and neogenesis , . Considering that DPP-4 is found both as a soluble enzyme in biological fluids  and as a serine protease on the surface of a variety of cell types, DPP-4 inhibitors have the potential to be multi-target compounds with (metabolically) favorable effects not limited to pancreatic islet cells. DPP-4 is also known as CD26, a T-cell marker, with a co-stimulatory role in T-cell activation through an interaction with adenosine deaminase (ADA) or caveolin (on antigen-presenting cells) –. Of interest, type 1 diabetic patients have increased numbers of fully differentiated effector/memory CD8+ T cells expressing high levels of CD26 . CD26hi cells proliferate vigorously in response to soluble antigens, secrete T helper (Th1) cytokines (e.g. IL-2, IFN-γ), and have transendothelial migration potential .
12 (1): 103–9. Therefore, DPP-4 inhibitors are designed to protect people from hypoglycemia and should ideally act only in response to such large intakes. Pre-clinical studies demonstrate that DPP-4 inhibitors, alone or in combination with other drugs, can partially correct hyperglycemia in diabetic mice , –, although conflicting data have also been published –. included a control group without diabetes. A first study reported decreased insulin requirements in new-onset type 1 diabetics by addition of sitagliptin to exogenous insulin therapy (NCT01235819). Hence, the true DPP-4 activity in vivo may be higher than the measured values suggest. These include, but are not limited to, miRNA 200, 192, and 21.
Here, we investigate whether adding DPP-4 inhibition (MK626, a DPP-4 inhibitor with appropriate pharmacokinetic properties in mice) to a subtherapeutically low dose of monoclonal CD3 antibodies reverses diabetes in new-onset diabetic NOD mice and we provide insights in the mechanism of immunomodulation and β-cell repair/expansion by the combinatory immunotherapy. NOD mice, obtained from Prof. Wu (Beijing, China), were bred in our animal facility since 1989 under semi-barrier conditions. Mice were screened for glucosuria and considered diabetic if non-fasting blood glucose levels exceeded 200 mg/dl for 2 consecutive days (AccuCheck, Roche Diagnostics, Vilvoorde, Belgium). DPP-IV inhibitors are one of several new classes of antidiabetic medications in development for type 2 diabetes. All animal breeding and experiments were approved by the ethical committee of the Katholieke Universiteit Leuven (#087-2009).