Impact of GLP-1 receptor agonists on major gastrointestinal disorders for type 2 diabetes mellitus: a mixed treatment comparison meta-analysis

TLQP-21 facilitates diabetic wound healing by inducing angiogenesis through alleviating high glucose-induced injuries on endothelial progenitor cells

Diabetes mellitus (DM) is a metabolic disease with multiple complications, including diabetic cutaneous wounds, which lacks effective treating strategies and severely influences the patients' life. Endothelial progenitor cells (EPCs) are reported to participate in maintaining the normal function of blood vessels, which plays a critical role in diabetic wound healing. TLQP-21 is a VGF-derived peptide with promising therapeutic functions on DM. Herein, the protective effects of TLQP-21 on diabetic cutaneous wound and the underlying mechanism will be investigated. Cutaneous wound model was established in T2DM mice, followed by administering 120 nmol/kg and 240 nmol/kg TLQP-21 once a day for 12 days. Decreased wound closure, reduced number of capillaries and EPCs, declined tube formation function of EPCs, and inactivated PI3K/AKT/eNOS signaling in EPCs were observed in T2DM mice, which were sharply alleviated by TLQP-21. Normal EPCs were extracted from mice and stimulated by high glucose (HG), followed by incubated with TLQP-21 in the presence or absence of LY294002, an inhibitor of PI3K. The declined cell viability, increased apoptotic rate, reduced number of migrated cells, declined migration distance, repressed tube formation function, and inactivated PI3K/AKT/eNOS signaling observed in HG-treated EPCs were markedly reversed by TLQP-21, which were dramatically abolished by the co-culture of LY294002. Collectively, TLQP-21 facilitated diabetic wound healing by inducing angiogenesis through alleviating HG-induced injuries on EPCs.

Increased expression of glucagon-like peptide-1 and cystic fibrosis transmembrane conductance regulator in the ileum and colon in mouse treated with metformin

Metformin, an oral medication, is prescribed to patients with type 2 diabetes mellitus. Although the efficacy, safety, and low economic burden of metformin on patients have long been recognized, approximately 5% of the patients treated with this drug develop severe diarrhea and discontinue the treatment. We previously reported that 1,000 mg·kg^-1·day^-1 of metformin induced diarrhea in diabetic obese (db/db) mice and wood creosote (traditional medication for diarrhea) ameliorated the symptoms. In this study, we attempted to elucidate the molecular mechanisms by which metformin induces diarrhea. Cystic fibrosis transmembrane conductance regulator (CFTR) is a key ion (chloride) channel in cyclic adenosine monophosphate (cAMP)-induced diarrhea. Metformin treatment increased bile flow (bile acids and bilirubin) in the ileum of mice. In addition, the treatment was accompanied by an increase in mRNA and protein levels of CFTR in the mucosa of the ileum and colon in both wild-type (C57BL/6J) and db/db mice. Glucagon-like peptide-1 (GLP-1), as well as cholic acid, induces CFTR mRNA expression in human colon carcinoma Caco-2 cells through cAMP signaling. Although wood creosote (10 mg/kg) ameliorated diarrhea symptoms, it did not alter the mRNA levels of Glp-1 or Cftr. Similar to overeating, metformin upregulated GLP-1 and CFTR expression, which may have contributed to diarrhea symptoms in mice. Although we could not identify db/db mouse-specific factors associated with metformin-induced diarrhea, these factors may modulate colon function. Wood creosote may not interact with these factors but ameliorates diarrhea symptoms.

The correlations between steady-state concentration, duration of action and molecular weight of GLP-1RAs and their efficacy and gastrointestinal side effects in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

To assess the influence of steady-state concentration, duration of action and molecular weight of glucagon-like peptide-1 receptor (GLP-1RA) on efficacy and gastrointestinal (GI) side effects in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, the Cochrane Center Register of Controlled Trials for Studies and Clinicaltrial.gov were searched from inception to April 2022. Randomized controlled trials (RCTs) comparing GLP-1RA versus non-GLP-1RA agents in patients with T2DM were included. Sensitivity analyses on steady-state concentration, duration of action and molecular weight of GLP-1RA were conducted.

RESULTS

113 RCTs were included. Greater HbA1c reduction between GLP-1RA users versus non-GLP-1RA users was observed in the high-steady-state-concentration stratum and long-acting stratum compared with the low-steady-state-concentration stratum (P_{subgroup difference} = 0.0004) and short-acting stratum (P_{subgroup difference}<0.0001). The risk of GI adverse events in GLP-1RA users versus non-GLP-1RA users was decreased in the high-steady-state-concentration stratum, long-acting stratum and heavy-molecular-weight stratum compared with low-steady-state-concentration stratum (P_{subgroup difference}<0.0001), short-acting stratum (P_{subgroup difference} = 0.002) and light-molecular-weight stratum (P_{subgroup difference} = 0.0008).

CONCLUSION

GLP-1RA with high steady-state concentration and long duration of action showed better hypoglycemic effect. GLP-1RA with high steady-state concentration, long duration of action and heavy molecular weight was associated with lower risk of GI adverse events.

Effectiveness and safety of new oral and injectable agents for in-hospital management of type 2 diabetes in general wards: Systematic review and meta-analysis

BACKGROUND

Current guidelines recommend insulin alone for in-hospital management of diabetes, but growing information suggests that new oral or injectable agents may be as effective and safe.

METHODS

Systematic review and meta-analysis with evidence from randomized (RCT) and non-randomized (NRS) studies in PubMed, EMBASE and LILACS databases up to February 10, 2022, for studies including hospitalized type 2 diabetes patients, comparing dipeptidyl peptidase 4 inhibitors (DPP4i), sodium glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonist (GLP1Ra) with insulin alone for glycemic control and safety outcomes.

FINDINGS

7 RCT and 3 NRTs were included. There were no differences in mean blood glucose, measurements within range or rate of hypoglycemia between DPP4i and insulin. We found a lower mean glucose for GLP1Ra plus insulin subgroup (-16.36 mg/dL, 95 % CI -27.31, -5.41; I² = 0 %) with lower incidence of hypoglycemia < 70 mg/dL with GLP1Ra (RR 0.31, CI 95 % 0.14-0.70, I² = 0 %). SGLT2i data was limited. Adverse events rates were similar between treatments.

CONCLUSION

Our review suggests that inpatient management in the general ward with DPP4i and GLP1Ra is as effective and safe as management with insulin. More randomized studies are required to support these findings before they could be recommended as usual practice.

Optimal dose of tirzepatide for type 2 diabetes mellitus: A meta-analysis and trial sequential analysis

Objective

The purpose of this study is to evaluate the optimal dose of tirzepatide (TZP) for the treatment of type 2 diabetes mellitus (T2DM) by meta-analysis and trial sequential analysis (TSA).

Methods

Clinical trials of TZP for T2DM were obtained by searching 8 databases with a time limit from database creation to May 2022. Mean differences (MD) and 95% confidence intervals (95%CI) were used for continuous variables, and relative risk (RR) and 95%CI were used for dichotomous variables.

Results

Compared with TZP 5 mg, meta-analysis showed that TZP 10 mg significantly reduced glycosylated hemoglobin type A1c (HbA1c) (MD −0.24, 95%CI −0.31~-0.17, P &lt; 0.00001), fasting serum glucose (FSG) (MD −5.82, 95%CI −8.35~-3.28, P &lt; 0.00001) and weight (MD −2.47, 95%CI −2.95~-1.98, P &lt; 0.00001), and TZP 15 mg significantly reduced HbA1c (MD −0.37, 95%CI −0.44~-0.29, P &lt; 0.00001), FSG (MD −8.52, 95%CI −11.07~-5.98, P &lt; 0.00001) and weight (MD −4.63, 95%CI −5.45~-3.81, P &lt; 0.00001). Compared with TZP 10 mg, TZP 15 mg dramatically reduced HbA1c (MD −0.12, 95%CI −0.19~-0.05, P = 0.001), FSG (MD −2.73, 95%CI −5.29~-0.17, P = 0.04) and weight (MD −2.18, 95%CI −2.67~-1.70, P &lt; 0.00001). The TSA indicated that the benefits observed in the current information set were conclusive, except for the FSG of “TZP 15 mg vs. TZP 10 mg”. In terms of safety endpoints, meta-analysis revealed that there was no significant difference in the serious adverse events (AEs), major adverse cardiovascular events-4 (MACE-4), cardiovascular death, hypertension, cancer and hypoglycemic of the three dose groups of TZP. Compared with TZP 5 mg, TZP 10 mg increased total adverse events (RR 1.06, 95%CI 1.01~1.11, P = 0.03) and gastrointestinal (GI) AEs (RR 1.17, 95%CI 1.03~1.33, P = 0.02), and TZP 15 mg increased total AEs (RR 1.10, 95%CI 1.05~1.15, P = 0.0001). There were no significant differences in total AEs and GI AEs for TZP 15 mg compared to TZP 10 mg. The TSA demonstrated that the total AEs of “TZP 15 mg vs. TZP 5 mg” were conclusive.

Conclusions

TZP 15 mg &gt;TZP 10 mg &gt; TZP 5 mg in terms of lowering glycemia and reducing weight. TZP 5 mg &gt; TZP 10 mg = TZP 15 mg in terms of safety. On this basis, we recommend TZP 5 mg as the first-choice dose for patients with T2DM to minimize AEs while reducing glycemia and weight. If patients cannot effectively control their glycemia after taking TZP 5 mg, it is recommended to take TZP 15 mg directly to achieve the best effect of glycemic reduction. However, most of the included studies have the background of basic medication, the independent efficacy and safety of different doses of TZP still need to be tested.

Systematic review registration

Unique Identifier: CRD42022341966.

Role of Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists in Hypoglycemia

A relatively recent addition to the arsenal of antidiabetic drugs used for the treatment of type 2 diabetes mellitus (T2DM) has been the “incretin mimetics,” a group of drugs that work on the glucagon-like peptide-1 (GLP-1) receptor and enhance insulin secretion from the pancreatic β-cells in a glucose-dependent manner, more potently in hyperglycemic conditions, while suppressing glucagon secretion at the same time. Therefore, it was assumed that this class of drugs would have a lower risk of hypoglycemia than insulin secretagogues like sulphonylureas. However, GLP-1 receptor agonists have been proposed to cause hypoglycemia in healthy normoglycemic subjects implying that their action is not as glucose-dependent as once thought. Other studies concluded that they might not induce hypoglycemia and the risk is dependent on other individual factors. However, the FDA announced that the 12 GLP-1 receptor agonists currently available on the market had potential safety signs and evaluated the need for regulatory action. This review provides an overview of the studies that investigated the possible hypoglycemic effect of GLP-1 receptor agonists. In addition, the current review describes other adverse effects of GLP-1 receptor agonist treatment.

Efficacy and safety of PEGylated exenatide injection (PB-119) in treatment-naive type 2 diabetes mellitus patients: a Phase II randomised, double-blind, parallel, placebo-controlled study

AIMS/HYPOTHESIS

Glucagon-like peptide 1 receptor agonists (GLP-1 RA) such as exenatide are used as monotherapy and add-on therapy for maintaining glycaemic control in patients with type 2 diabetes mellitus. The current study investigated the safety and efficacy of once-weekly PB-119, a PEGylated exenatide injection, in treatment-naive patients with type 2 diabetes.

METHODS

In this Phase II, randomised, placebo-controlled, double-blind study, we randomly assigned treatment-naive Chinese patients with type 2 diabetes in a 1:1:1:1 ratio to receive subcutaneous placebo or one of three subcutaneous doses of PB-119 (75, 150, and 200 μg) for 12 weeks. The primary endpoint was the change in HbA_1c from baseline to week 12, and other endpoints were fasting plasma glucose, 2 h postprandial glucose (PPG), and proportion of patients with HbA_1c < 53 mmol/mol (<7.0%) and ≤48 mmol/mol (≤6.5%) at 2, 4, 8 and 12 weeks of treatment. Safety was assessed in all patients who received at least one dose of study drug.

RESULTS

We randomly assigned 251 patients to one of the four treatment groups (n = 62 in placebo and 63 each in PB-119 75 μg, 150 μg and 200 μg groups). At the end of 12 weeks, mean differences in HbA_1c in the treatment groups were -7.76 mmol/mol (95% CI -9.23, -4.63, p < 0.001) (-0.72%, 95% CI -1.01, -0.43), -12.89 mmol/mol (95% CI -16.05, -9.72, p < 0.001) (-1.18%, 95% CI -1.47, -0.89) and -11.14 mmol/mol (95% CI -14.19, -7.97, p <0 .001) (-1.02%, 95% CI -1.30, -0.73) in the 75 μg, 150 μg and 200 μg PB-119 groups, respectively, compared with that in the placebo group after adjusting for baseline HbA_1c. Similar results were also observed for other efficacy endpoints across different time points. There was no incidence of treatment-emergent serious adverse event, severe hypoglycaemia or death.

CONCLUSIONS/INTERPRETATION

All tested PB-119 doses had superior efficacy compared with placebo and were safe and well tolerated over 12 weeks in treatment-naive Chinese patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03520972 FUNDING: The study was funded by National Major Scientific and Technological Special Project for Significant New Drugs Development and PegBio.

GLP-1 and Intestinal Diseases

Accumulating evidence implicates glucagon-like peptide-1 (GLP-1) to have, beyond glucose maintenance, a beneficial role in the gastrointestinal tract. Here, we review emerging data investigating GLP-1 as a novel treatment for intestinal diseases, including inflammatory bowel diseases, short-bowel syndrome, intestinal toxicities and coeliac disease. Possible beneficial mechanisms for these diseases include GLP-1′s influence on gastric emptying, its anti-inflammatory properties and its intestinotrophic effect. The current knowledge basis derives from the available GLP-1 agonist treatments in experimental animals and small clinical trials. However, new novel strategies including dual GLP-1/GLP-2 agonists are also in development for the treatment of intestinal diseases.

The Future of Incretin-Based Approaches for Neurodegenerative Diseases in Older Adults: Which to Choose? A Review of their Potential Efficacy and Suitability

The current treatment options for neurodegenerative diseases in older adults rely mainly on providing symptomatic relief. Yet, it remains imperative to identify agents that slow or halt disease progression to avoid the most disabling features often associated with advanced disease stages. A potential overlap between the pathological processes involved in diabetes and neurodegeneration has been established, raising the question of whether incretin-based therapies for diabetes may also be useful in treating neurodegenerative diseases in older adults. Here, we review the different agents that belong to this class of drugs (GLP-1 receptor agonists, dual/triple receptor agonists, DPP-4 inhibitors) and describe the data supporting their potential role in treating neurodegenerative conditions including Parkinson's disease and Alzheimer's disease. We further discuss whether there are any distinctive properties among them, particularly in the context of safety or tolerability and CNS penetration, that might facilitate their successful repurposing as disease-modifying drugs. Proof-of-efficacy data will obviously be of the greatest importance, and this is most likely to be demonstrable in agents that reach the central nervous system and impact on neuronal GLP-1 receptors. Additionally, however, the long-term safety and tolerability (including gastrointestinal side effects and unwanted weight loss) as well as the route of administration of this class of agents may also ultimately determine success and these aspects should be considered in prioritising which approaches to subject to formal clinical trial evaluations.

Safety, Pharmacokinetics and Pharmacodynamics of Multiple Escalating Doses of PEGylated Exenatide (PB-119) in Healthy Volunteers

BACKGROUND AND OBJECTIVE

At present, the deficiency of β-cell function is progressive in patients with type 2 diabetes mellitus. Exenatide cannot only control blood glucose well, but also promotes the regeneration and proliferation of islet β-cells and improves the function of β cells. However, it needs to be given twice a day, and there are many adverse reactions such as nausea. PEGylated exenatide (study code: PB-119) needs to be administered only once a week. The purpose of this experiment was to evaluate the safety, pharmacokinetics and pharmacodynamics of an escalating dose regimen of subcutaneous PEGylated exenatide injections in healthy subjects.

METHODS

Twelve healthy young adult subjects in each group received once-weekly subcutaneous injections of 165 μg, 330 μg, and 660 μg PEGylated exenatide for 6 weeks. Plasma drug concentration was determined in venous blood collected across selected time points. Safety and tolerability were evaluated by monitoring adverse events, laboratory parameters, and electrocardiogram. Blood glucose, insulin,  glucagon and C peptide were monitored at different time points to evaluate the pharmacodynamics of PEGylated exenatide.

RESULTS

A total of 11, 10, and 12 subjects completed the study in 165 µg, 330 µg, and 660 µg dose groups, respectively. After 6 consecutive weeks of administration, the t_1/2 in the 165 μg, 330 μg, and 660 µg dose groups was 55.67 ± 11.03 h, 56.99 ± 21.37 h, and 54.81 ± 13.87 h, respectively. The C_avg was 4.22 ± 0.78 ng/ml, 6.03 ± 1.43 ng/ml, and 10.50 ± 3.06 ng/ml, respectively. AUCss was 708.59 ± 131.87 h•ng/ml, 1012.63 ± 240.79 h•ng/ml, and 1763.81 ± 514.50 h•ng/ml, respectively. The accumulation index was 1.15 ± 0.07, 1.17 ± 0.11, and 1.14 ± 0.07. The CLss/F was 241.25 ± 51.13 ml/h, 341.53 ± 73.62 ml/h, and 450.06 ± 313.76 ml/h, respectively. A total of 10 of 36 (27.78%) subjects in the three dose groups developed specific antibodies after consecutive subcutaneous injections of PEGylated exenatide. The C_avg and C_max were higher than those of antibody-negative subjects. Furthermore, in antibody-positive subjects, CLss/F, t_1/2, AUC_τ, accumulation index, MRT_(0-inf) and other parameters were lower than those of antibody-negative subjects. In the 165 μg dose group, two subjects (16.67%) experienced 4 adverse events. In the 330 μg dose group, no subjects reported adverse events. In the 660 μg dose group, 8 subjects (66.67%) reported 16 adverse events, which were mostly gastrointestinal. There were no significant changes in the pharmacodynamic parameters except the glucagon level at day 36 in the 660 µg dose group, the 2h postprandial insulin and C peptide levels at day 36 and day 50 in the 165 μg dose group compared with baseline (- 1 day).

CONCLUSION

A once-weekly subcutaneous injection of 165 µg and 330 µg PEGylated exenatide is safe. No significant effects on blood glucose or pancreatic hormone levels were observed in the subjects within these dose groups. The pharmacokinetic parameters of PEGylated exenatide may be affected by immunogenicity.

CLINICAL TRIALS REGISTRATION

The study is registered at clinicaltrials.gov (No. NCT03062774).

Evaluation of Characteristics of Gastrointestinal Adverse Events with Once-Weekly Dulaglutide Treatment in Chinese Patients with Type 2 Diabetes: A Post Hoc Pooled Analysis of Two Randomized Trials

INTRODUCTION

Gastrointestinal (GI) events are a common side effect of glucagon-like peptide 1 (GLP-1) receptor agonists (RA) class. This post hoc analysis assessed the characteristics of GI adverse events in Chinese patients with type 2 diabetes (T2D) who were treated with once-weekly dulaglutide from two randomized clinical trials.

METHODS

Chinese patients with T2D, treated with once-weekly dulaglutide (1.5 mg and 0.75 mg) from two phase III multicenter trials (AWARD-CHN1 and AWARD-CHN2) were included. Descriptive statistics were used to present the data. The characteristics (incidence, severity, onset, duration, and time of occurrence) of GI adverse events reported through 26 weeks in a Chinese subpopulation from the two trials were investigated.

RESULTS

A total of 787 Chinese patients with T2D were included in this analysis. Up to week 26, 225 patients (28.6%) reported at least one GI treatment-emergent adverse event (TEAE). The most frequently reported GI TEAEs were diarrhea (13.1%), nausea (6.6%), abdominal distension (6.4%), and vomiting (3.0%), with most being categorized as mild to moderate in severity in proportions of 92%, 88%, 94%, and 83%, respectively. A total of 12 patients (1.5%) discontinued the dulaglutide treatment as a result of GI TEAEs. The median duration of the first reported GI TEAEs was 4.0, 5.0, 12.5, and 4.0 days for diarrhea, nausea, abdominal distension, and vomiting, respectively. The incidence of GI TEAEs was more frequent during the first 2 weeks of dulaglutide treatment; however, the incidence declined rapidly after 2 weeks and remained low until week 26.

CONCLUSIONS

Most of the GI TEAEs associated with once-weekly dulaglutide (1.5 mg and 0.75 mg) were mild to moderate in severity. The incidence of GI TEAEs was more pronounced during the first 2 weeks of dulaglutide treatment but declined rapidly as treatment continued, and was low at week 26, indicating that dulaglutide was well tolerated in Chinese patients with T2D.

TRIAL REGISTRATION

NCT01648582 and NCT01644500.

Glucagon-Like Peptide-1 Receptor Analogues in Type 2 Diabetes: Their Use and Differential Features

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are well established as effective adjuncts to lifestyle modification in the treatment of type 2 diabetes (T2D) as monotherapy or in combination with oral glucose-lowering drugs ± insulin. The six subcutaneous GLP-1RA formulations (i.e. twice-daily exenatide, once-daily liraglutide and lixisenatide, and once-weekly dulaglutide, exenatide and semaglutide) currently available in the EU and USA have many similarities, but also some unique features and properties. By stimulating GLP-1 receptors, GLP-1RAs increase insulin secretion and suppress glucagon release in a glucose-dependent manner, thereby improving clinical and patient-reported outcomes related to glycaemic control and weight. They also have been shown to reduce, or at least not increase, the risk of major cardiovascular outcomes. GLP-1RAs are generally well tolerated, with gastrointestinal and injection-site reactions being the most troublesome drug-related adverse events, and are associated with a very low intrinsic risk of hypoglycaemia. Treatment with GLP-1RAs should be customized to meet the clinical needs and personal preferences of the individual.

Engineering of a GLP-1 analogue peptide/anti-PCSK9 antibody fusion for type 2 diabetes treatment

Type 2 diabetes (T2D) is a complex and progressive disease requiring polypharmacy to manage hyperglycaemia and cardiovascular risk factors. However, most patients do not achieve combined treatment goals. To address this therapeutic gap, we have developed MEDI4166, a novel glucagon-like peptide-1 (GLP-1) receptor agonist peptide fused to a proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralising antibody that allows for glycaemic control and low-density lipoprotein cholesterol (LDL-C) lowering in a single molecule. The fusion has been engineered to deliver sustained peptide activity in vivo in combination with reduced potency, to manage GLP-1 driven adverse effects at high dose, and a favourable manufacturability profile. MEDI4166 showed robust and sustained LDL-C lowering in cynomolgus monkeys and exhibited the anticipated GLP-1 effects in T2D mouse models. We believe MEDI4166 is a novel molecule combining long acting agonist peptide and neutralising antibody activities to deliver a unique pharmacology profile for the management of T2D.

ZY15557, a novel, long acting inhibitor of dipeptidyl peptidase-4, for the treatment of Type 2 diabetes mellitus

BACKGROUND AND PURPOSE

Dipeptidyl peptidase (DPP)-4 inhibitors increase levels of glucagon-like peptide-1 (GLP-1) and provide clinical benefit in the treatment of type 2 diabetes mellitus. As longer acting inhibitors have therapeutic advantages, we developed a novel DPP-4 inhibitor, ZY15557, that has a sustained action and long half-life.

EXPERIMENTAL APPROACH

We studied the potency, selectivity, efficacy and duration of action of ZY15557, in vitro, with assays of DPP-4 activity. In vivo, the pharmacodymamics and pharmacokinetics of ZY15557 were studied, using db/db mice and Zucker fatty rats, along with normal mice, rats, dogs and non-human primates.

KEY RESULTS

ZY15557 is a potent, competitive and long acting inhibitor of DPP-4 (K_i 5.53 nM; K_off 3.2 × 10^-4 ·s^-1 , half-life 35.8 min). ZY15557 treatment inhibited DPP-4 activity, and enhanced active GLP-1 and insulin in mice and rats, providing dose-dependent anti-hyperglycaemic effects. Anti-hyperglycaemic effects were also observed in db/db mice and Zucker fatty rats. Following oral dosing, ZY15557 significantly inhibited plasma DPP-4 activity, determined ex vivo, in mice and rats for more than 48 h, and for up to 168 h in dogs and non-human primates. Allometric scaling predicts a half-life for ZY15557 in humans of up to 60 h.

CONCLUSIONS AND IMPLICATIONS

ZY15557 is a potent, competitive and long acting DPP-4 inhibitor. ZY15557 showed similar DPP-4 inhibition across different species. ZY15557 showed excellent oral bioavailability in preclinical species. It showed a low plasma clearance (CL) and large volume of distribution (V_ss ) across species, resulting in an extended half-life.

Successful Glycemic Control Decreases the Elevated Serum FGF21 Level without Affecting Normal Serum GDF15 Levels in a Patient with Mitochondrial Diabetes

Mitochondrial diabetes mellitus is a subtype of diabetes linked to mutations in mitochondrial DNA. In patients with mitochondrial diabetes mellitus, the effect of glycemic control on the serum concentrations of fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15) has not been evaluated. FGF21 and GDF15 have been reported to be useful biomarkers for the diagnosis and severity assessment of mitochondrial diseases like mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Recent studies have shown FGF21 acts in an endocrine fashion to regulate glucose and lipid metabolism in type 2 diabetes mellitus, while the exact biological functions of GDF15 remain unknown. Although mitochondrial diabetes mellitus is commonly found in cases with mitochondrial diseases, the comparison of FGF21 and GDF15 levels between those with and without diabetes has not been performed. Here, we report a 24-year-old woman with mitochondrial diabetes mellitus, who showed a high level of serum FGF21, but not serum GDF15, at diagnosis. In our case, liraglutide, a glucagon-like peptide-1 receptor agonist, added to insulin glargine was effective for her glycemic control and showed no adverse effects, including gastrointestinal symptoms and hypoglycemia, during a 14-week observation. The successful glycemic control caused a decrease in the FGF21 level, without affecting the GDF15 level. Thus, we should consider patients' glycemic control levels in using FGF21 values for the diagnosis of mitochondrial diseases. In addition, sustained GDF15 levels during glycemic treatment in our case suggest the usefulness of GDF15 as a marker for clinical severity of muscle-manifested mitochondrial diseases.

Glucagon-like peptide-1 analogue, liraglutide, in experimental cerebral malaria: implications for the role of oxidative stress in cerebral malaria

BACKGROUND

Cerebral malaria from Plasmodium falciparum infection is major cause of death in the tropics. The pathogenesis of the disease is complex and the contribution of reactive oxygen and nitrogen species (ROS/RNS) in the brain is incompletely understood. Insulinotropic glucagon-like peptide-1 (GLP-1) mimetics have potent neuroprotective effects in animal models of neuropathology associated with ROS/RNS dysfunction. This study investigates the effect of the GLP-1 analogue, liraglutide against the clinical outcome of experimental cerebral malaria (ECM) and Plasmodium falciparum growth. Furthermore the role of oxidative stress on ECM pathogenesis is evaluated.

METHODS

ECM was induced in Plasmodium berghei ANKA-infected C57Bl/6j mice. Infected Balb/c (non-cerebral malaria) and uninfected C57Bl/6j mice were included as controls. Mice were treated twice-daily with vehicle or liraglutide (200 μg/kg). ROS/RNS were quantified with in vivo imaging and further analyzed ex vivo. Brains were assayed for cAMP, activation of cAMP response element binding protein (CREB) and nitrate/nitrite. Plasmodium falciparum was cultivated in vitro with increasing doses of liraglutide and growth and metabolism were quantified.

RESULTS

The development and progression of ECM was not affected by liraglutide. Indeed, although ROS/RNS were increased in peripheral organs, ROS/RNS generation was not present in the brain. Interestingly, CREB was activated in the ECM brain and may protect against ROS/RNS stress. Parasite growth was not adversely affected by liraglutide in mice or in P. falciparum cultures indicating safety should not be a concern in type-II diabetics in endemic regions.

CONCLUSIONS

Despite the breadth of models where GLP-1 is neuroprotective, ECM was not affected by liraglutide providing important insight into the pathogenesis of ECM. Furthermore, ECM does not induce excess ROS/RNS in the brain potentially associated with activation of the CREB system.

Adverse Effects Associated With Newer Diabetes Therapies

The increasing number of newer type 2 diabetes therapies has allowed providers an increased armamentarium for the optimal management of patients with diabetes. In fact, these newer agents have unique benefits in the management of type 2 diabetes. However, they are also associated with certain adverse effects. This review article aims to describe the notable adverse effects of these newer antidiabetic therapies including the glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase-4 inhibitors, and the sodium-glucose cotransporter 2 inhibitors. The adverse effects reviewed herein include pancreatitis, medullary thyroid carcinoma, heart failure, gastrointestinal disturbances, renal impairment, and genitourinary infections. More clinical data are necessary to solidify the association of some of these adverse effects with the newer diabetes agents. However, it is important for health care practitioners to be well informed and prepared to properly monitor patients for these adverse effects.

GLP-1 based therapies: clinical implications for gastroenterologists

The gut-derived incretin hormone, glucagon-like peptide 1 (GLP-1) lowers postprandial blood glucose levels by stimulating insulin and inhibiting glucagon secretion. Two novel antihyperglycaemic drug classes augment these effects; GLP-1 receptor agonists and inhibitors of the GLP-1 degrading enzyme dipeptidyl peptidase 4. These so called GLP-1 based or incretin based drugs are increasingly used to treat type 2 diabetes, because of a low risk of hypoglycaemia and favourable effect on body weight, blood pressure and lipid profiles. Besides glucose control, GLP-1 functions as an enterogastrone, causing a wide range of GI responses. Studies have shown that endogenous GLP-1 and its derived therapies slow down digestion by affecting the stomach, intestines, exocrine pancreas, gallbladder and liver. Understanding the GI actions of GLP-1 based therapies is clinically relevant; because GI side effects are common and need to be recognised, and because these drugs may be used to treat GI disease.

A systematic review of the safety of incretin-based therapies in type 2 diabetes

INTRODUCTION

Large randomized clinical trials have demonstrated that incretin-based therapies provide effective glycemic control in type 2 diabetes. Long-term safety assessments are ongoing.

METHODS

This systematic review of incretin-based therapy safety is based on 112 randomized clinical trials of duration ≥26 weeks published between January 2000 and February 2015 in patients with type 2 diabetes.

RESULTS

As expected, hypoglycemia rates were lower with dipeptidyl peptidase-4 inhibitors (DPP-4is) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) versus other oral antidiabetic drugs and insulin. The most common adverse events were infection and infestation (DPP-4is) and gastrointestinal (GLP-1 RAs). Pancreatitis cases were rare across all studies and, in the SAVOR-TIMI and EXAMINE trials, pancreatitis rates were similar in DPP-4i- and placebo-treated patients. No thyroid tumors were reported, and increased risk of cardiovascular events was not associated with DPP-4is in SAVOR-TIMI and EXAMINE, albeit over a short follow-up period.

CONCLUSIONS

Overall, incretin-based therapies were well tolerated; however, their long-term safety profile should continue to be periodically assessed.

Gastrointestinal actions of glucagon-like peptide-1-based therapies: glycaemic control beyond the pancreas

The gastrointestinal hormone glucagon-like peptide-1 (GLP-1) lowers postprandial glucose concentrations by regulating pancreatic islet-cell function, with stimulation of glucose-dependent insulin and suppression of glucagon secretion. In addition to endocrine pancreatic effects, mounting evidence suggests that several gastrointestinal actions of GLP-1 are at least as important for glucose-lowering. GLP-1 reduces gastric emptying rate and small bowel motility, thereby delaying glucose absorption and decreasing postprandial glucose excursions. Furthermore, it has been suggested that GLP-1 directly stimulates hepatic glucose uptake, and suppresses hepatic glucose production, thereby adding to reduction of fasting and postprandial glucose levels. GLP-1 receptor agonists, which mimic the effects of GLP-1, have been developed for the treatment of type 2 diabetes. Based on their pharmacokinetic profile, GLP-1 receptor agonists can be broadly categorized as short- or long-acting, with each having unique islet-cell and gastrointestinal effects that lower glucose levels. Short-acting agonists predominantly lower postprandial glucose excursions, by inhibiting gastric emptying and intestinal glucose uptake, with little effect on insulin secretion. By contrast, long-acting agonists mainly reduce fasting glucose levels, predominantly by increased insulin and reduced glucagon secretion, with potential additional direct inhibitory effects on hepatic glucose production. Understanding these pharmacokinetic and pharmacodynamic differences may allow personalized antihyperglycaemic therapy in type 2 diabetes. In addition, it may provide the rationale to explore treatment in patients with no or little residual β-cell function.

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

A meta-analysis was conducted to assess the clinical efficacy and safety of dulaglutide in patients with type 2 diabetes mellitus (T2DM). Medline, Embase, Cochrane Library and www. clinicaltrials. gov (up to February 15^th, 2015) were searched. Randomized controlled trials comparing dulaglutide to other drugs for T2DM were collected. Twelve RCTs were included, and the overall bias was low. As the monotherapy, compared with control (placebo, metformin and liraglutide), dulaglutide resulted in a significant reduction in HbA1c (WMD, −0.68%; 95% CI, −0.95 to −0.40), FPG (WMD, −0.90 mmol/L; 95% CI, −1.28 to −0.52), a similar risk of hypoglycemia (7.8% vs. 10.6%), less body weight loss (WMD, 0.51 kg; 95% CI, 0.27 to 0.75). As an add-on intervention with oral antihyperglycemic medication (OAM) and insulin, compared with control (placebo, sitagliptin, exenatide, liraglutide and glargine), dulaglutide lowered HbA1c (WMD, −0.51%; 95% CI, −0.68 to −0.35) and body weight significantly (WMD, −1.30 kg, 95% CI, −1.85 to −1.02) notably, and elicited a similar reduction in FPG (WMD, −0.19 mmol/L; 95% CI, −1.20 to 0.82), an similar incidence of hypoglycemia (24.5% vs. 24.5%). This meta-analysis revealed the use of dulaglutide as a monotherapy or an add-on to OAM and lispro appeared to be effective and safe for adults with T2DM.

Albiglutide: Is a better hope against diabetes mellitus?

Type-2 diabetes mellitus (T2DM) is the chronic metabolic disorder which provokes several pitfall signalling. Though, a series of anti-diabetic drugs are available in the market but T2DM is still a huge burden on the developed and developing countries. Numerous studies and survey predict the associated baleful circumstances in near future due to incessant increase in this insidious disorder. The novelty of recent explored anti-diabetic drugs including glitazone, glitazaar and gliflozines seems to be vanished due to their associated toxic side effects. Brown and Dryburgh (1970) isolated an intestinal amino acid known as gastric inhibitory peptide (GIP) which had insulinotropic activity. Subsequently in 1985, another incretin glucagon likes peptide 1 (GLP-1) having potent insulinotropic properties was discovered by Schmidt and his co-workers. On the basis of results' obtained by Phase III Harmony program FDA approved (14 April, 2014) new GLP-1 agonist 'Albiglutide (ALB)', in addition to exiting components Exenatide (Eli Lilly, 2005) and Liraglutide (Novo Nordisk, 2010). ALB stimulates the release of protein kinase A (PKA) via different mechanisms which ultimately leads to increase in intracellular Ca(2+) levels. This increased intracellular Ca(2+) releases insulin vesicle from β-cells. In-addition, ALB being resistant to degradation by dipeptidyl peptidase-4 (DPP-4) and has longer half life. DPP-4 can significantly degrade the level of GLP-1 agonist by hydrolysis. In spite of potent anti-hypergycemic activity, ALB has pleiotropic action of improving cardiovascular physiology. In light of these viewpoints we reveal the individual pharmacological profile of ALB and the critical analyse about its future perspective in present review.

Effects of three injectable antidiabetic agents on glycaemic control, weight change and drop-out in type 2 diabetes suboptimally controlled with metformin and/or a sulfonylurea: A network meta-analysis

AIMS

The objective of this review was to assess glucagon-like peptide-1 receptor agonists (GLP-1 RAs), basal insulin, and premixed insulin among participants with type 2 diabetes inadequately controlled with metformin and/or a sulfonylurea.

METHODS

We searched PubMed, EmBase, and the Cochrane Library to identify eligible randomized controlled trials (RCTs) for a network meta-analysis.

RESULTS

A total of 17 RCTs involving 5874 adult individuals were included. Compared with placebo, all three therapies showed a significant effect on achieving target glycated hemoglobin (HbA1c) (GLP-1 RAs: 31.7%, 95% CI, 24.7-38.6%; premixed insulin: 31.1%, 95% CI, 20.4-41.8%; basal insulin: 26.0%, 95% CI, 16.4-35.7%). However, there was no significant difference between the three therapies. A similar result was found in HbA1c reduction. The use of GLP-1 RAs resulted in significant body weight loss (-3.73 kg, 95% CI, -4.52 to -2.95 kg vs. basal insulin and -5.27 kg, 95% CI, -6.17 to -4.36 kg vs. premixed insulin) but there was a higher drop-out rate of participants. Premixed insulin seemed associated with more severe hypoglycemic episodes.

CONCLUSIONS

The three injectables had similar impact on glycemic control but other differentiating features relevant to the management of type 2 diabetes with GLP-1 RAs having the most favorable profile.

The Role of Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes: Understanding How Data Can Inform Clinical Practice in Korea

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduce glycosylated hemoglobin (HbA1c, 0.5% to 1.0%), and are associated with moderate weight loss and a relatively low risk of hypoglycemia. There are differences between Asian and non-Asian populations. We reviewed available data on GLP-1RAs, focusing on Korean patients, to better understand their risk/benefit profile and help inform local clinical practice. Control of postprandial hyperglycemia is important in Asians in whom the prevalence of post-challenge hyperglycemia is higher (vs. non-Asians). The weight lowering effects of GLP-1RAs are becoming more salient as the prevalence of overweight and obesity among Korean patients increases. The higher rate of gastrointestinal adverse events amongst Asian patients in clinical trials may be caused by higher drug exposure due to the lower body mass index of the participants (vs. non-Asian studies). Data on the durability of weight loss, clinically important health outcomes, safety and optimal dosing in Korean patients are lacking. Use of GLP-1RAs is appropriate in several patient groups, including patients whose HbA1c is uncontrolled, especially if this is due to postprandial glucose excursions and patients who are overweight or obese due to dietary problems (e.g., appetite control). The potential for gastrointestinal adverse events should be explained to patients at treatment initiation to facilitate the promotion of better compliance.

Adverse Effects of GLP-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of injective anti-diabetic drugs that improve glycemic control and many other atherosclerosis-related parameters in patients with type 2 diabetes (T2D). However, the use of this relatively new class of drugs may be associated with certain adverse effects. Concerns have been expressed regarding the effects of these drugs on pancreatic and thyroid tissue, since animal studies and analyses of drug databases indicate an association of GLP-1 receptor agonists with pancreatitis, pancreatic cancer, and thyroid cancer. However, several meta-analyses failed to confirm a cause-effect relation between GLP-1 receptor agonists and the development of these adverse effects. One benefit of GLP-1 receptor agonists is that they do not cause hypoglycemia when combined with metformin or thiazolidinediones, but the dose of concomitant sulphonylurea or insulin may have to be decreased to reduce the risk of hypoglycemic episodes. On the other hand, several case reports have linked the use of these drugs, mainly exenatide, with the occurrence of acute kidney injury, primarily through hemodynamic derangement due to nausea, vomiting, and diarrhea. The most common symptoms associated with the use of GLP-1 receptor agonists are gastrointestinal symptoms, mainly nausea. Other common adverse effects include injection site reactions, headache, and nasopharyngitis, but these effects do not usually result in discontinuation of the drug. Current evidence shows that GLP-1 receptor agonists have no negative effects on the cardiovascular risk of patients with T2D. Thus, GLP-1 receptor agonists appear to have a favorable safety profile, but ongoing trials will further assess their cardiovascular effects. The aim of this review is to analyze critically the available data regarding adverse events of GLP-1 receptor agonists in different anatomic systems published in Pubmed and Scopus. Whenever possible, certain differences between GLP-1 receptor agonists are described. The review also provides the reader with structured data that compare the rates of the most common adverse effects for each of the various GLP-1 receptor agonists.

Adverse drug reactions associated with the use of liraglutide in patients with type 2 diabetes--focus on pancreatitis and pancreas cancer

INTRODUCTION

The glucagon-like peptide-1 (GLP-1) receptor agonist, liraglutide , is a widely used drug for the treatment of type 2 diabetes. Liraglutide is one of several incretin-based agents that have been suggested to be associated with pancreatitis and pancreas cancer. The suspicion accelerated after publication of an autopsy study claiming increased incidences of several pathological changes in pancreata from patients with diabetes treated with incretin-based drugs.

AREAS COVERED

The aim of the present review is to give an overview of the pharmacology of liraglutide and provide a review of adverse reactions associated with liraglutide with a focus on the risk of pancreatitis and pancreas cancer.

EXPERT OPINION

When comprehensively reviewing the available literature, no clear and significant associations between liraglutide and pancreatitis and/or pancreas cancer seem evident. However, a recently published analysis suggests a trend toward a slightly elevated risk of pancreatitis with GLP-1 receptor agonists (including liraglutide), which may become statistical significant as more data become available. Well-established side effects are of gastrointestinal origin, typical mild-to-moderate and of transient character. The risk of hypoglycemia associated with liraglutide treatment is low.

TLQP-21 protects human umbilical vein endothelial cells against high-glucose-induced apoptosis by increasing G6PD expression

Hyperglycemia causes oxidative stress that could damage vascular endothelial cells, leading to cardiovascular complications. The Vgf gene was identified as a nerve growth factor-responsive gene, and its protein product, VGF, is characterized by the presence of partially cleaved products. One of the VGF-derived peptides is TLQP-21, which is composed of 21 amino acids (residues 556-576). Past studies have reported that TLQP-21 could stimulate insulin secretion in pancreatic cells and protect these cells from apoptosis, which suggests that TLQP-21 has a potential function in diabetes therapy. Here, we explore the protective role of TLQP-21 against the high glucose-mediated injury of vascular endothelial cells. Using human umbilical vascular endothelial cells (HUVECs), we demonstrated that TLQP-21 (10 or 50 nM) dose-dependently prevented apoptosis under high-glucose (30 mmol/L) conditions (the normal glucose concentration is 5.6 mmol/L). TLQP-21 enhanced the expression of NAPDH, resulting in upregulation of glutathione (GSH) and a reduction in the levels of reactive oxygen species (ROS). TLQP-21 also upregulated the expression of glucose-6-phosphate dehydrogenase (G6PD), which is known as the main source of NADPH. Knockdown of G6PD almost completely blocked the increase of NADPH induced by TLQP-21, indicating that TLQP-21 functions mainly through G6PD to promote NADPH generation. In conclusion, TLQP-21 could increase G6PD expression, which in turn may increase the synthesis of NADPH and GSH, thereby partially restoring the redox status of vascular endothelial cells under high glucose injury. We propose that TLQP-21 is a promising drug for diabetes therapy.

Detection, evaluation and treatment of diabetes mellitus in chronic pancreatitis: recommendations from PancreasFest 2012

DESCRIPTION

Diabetes and glucose intolerance are common complications of chronic pancreatitis, yet clinical guidance on their detection, classification, and management is lacking.

METHODS

A working group reviewed the medical problems, diagnostic methods, and treatment options for chronic pancreatitis-associated diabetes for a consensus meeting at PancreasFest 2012.

RESULTS

Guidance Statement 1.1: Diabetes mellitus is common in chronic pancreatitis. While any patient with chronic pancreatitis should be monitored for development of diabetes, those with long-standing duration of disease, prior partial pancreatectomy, and early onset of calcific disease may be at higher risk. Those patients developing diabetes mellitus are likely to have co-existing pancreatic exocrine insufficiency. Guidance Statement 1.2: Diabetes occurring secondary to chronic pancreatitis should be recognized as pancreatogenic diabetes (type 3c diabetes). Guidance Statement 2.1: The initial evaluation should include fasting glucose and HbA1c. These tests should be repeated annually. Impairment in either fasting glucose or HbA1c requires further evaluation. Guidance Statement 2.2: Impairment in either fasting glucose or HbA1c should be further evaluated by a standard 75 g oral glucose tolerance test. Guidance Statement 2.3: An absent pancreatic polypeptide response to mixed-nutrient ingestion is a specific indicator of type 3c diabetes. Guidance Statement 2.4: Assessment of pancreatic endocrine reserve, and importantly that of functional beta-cell mass, should be performed as part of the evaluation and follow-up for total pancreatectomy with islet autotransplantation (TPIAT). Guidance Statement 3: Patients with pancreatic diabetes shall be treated with specifically tailored medical nutrition and pharmacologic therapies.

CONCLUSIONS

Physicians should evaluate and treat glucose intolerance in patients with pancreatitis.