Glucagon-Like Peptide-1 Receptor Agonists for Type 2 Diabetes: A Clinical Update of Safety and Efficacy

Glycemic control and cancer outcomes in oncologic patients with diabetes: an Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), Italian Society of Pharmacology (SIF) multidisciplinary critical view

BACKGROUND

 Increasing evidence suggests that diabetes increases the risk of developing different types of cancer. Hyperinsulinemia, hyperglycemia and chronic inflammation, characteristic of diabetes, could represent possible mechanisms involved in cancer development in diabetic patients. At the same time, cancer increases the risk of developing new-onset diabetes, mainly caused by the use of specific anticancer therapies. Of note, diabetes has been associated with a ∼10% increase in mortality for all cancers in comparison with subjects who did not have diabetes. Diabetes is associated with a worse prognosis in patients with cancer, and more recent findings suggest a key role for poor glycemic control in this regard. Nevertheless, the association between glycemic control and cancer outcomes in oncologic patients with diabetes remains unsettled and poorly debated.

PURPOSE

 The current review seeks to summarize the available evidence on the effect of glycemic control on cancer outcomes, as well as on the possibility that timely treatment of hyperglycemia and improved glycemic control in patients with cancer and diabetes may favorably affect cancer outcomes.

Drug repositioning in thyroid cancer treatment: the intriguing case of anti-diabetic drugs

Cancer represents the main cause of death worldwide. Thyroid cancer (TC) shows an overall good rate of survival, however there is a percentage of patients that do not respond or are refractory to common therapies. Thus new therapeutics strategies are required. In the past decade, drug repositioning become very important in the field of cancer therapy. This approach shows several advantages including the saving of: i) time, ii) costs, iii) de novo studies regarding the safety (just characterized) of a drug. Regarding TC, few studies considered the potential repositioning of drugs. On the other hand, certain anti-diabetic drugs, were the focus of interesting studies on TC therapy, in view of the fact that they exhibited potential anti-tumor effects. Among these anti-diabetic compounds, not all were judjed as appropriate for repositioning, in view of well documented side effects. However, just to give few examples biguanides, DPP-4-inhibitors and Thiazolidinediones were found to exert strong anti-cancer effects in TC. Indeed, their effects spaced from induction of citotoxicity and inhibition of metastatic spread, to induction of de-differentiation of TC cells and modulation of TC microenvironment. Thus, the multifacial anti-cancer effect of these compounds would make the basis also for combinatory strategies. The present review is aimed at discuss data from studies regarding the anti-cancer effects of several anti-diabetic drugs recently showed in TC in view of their potential repositioning. Specific examples of anti-diabetic repositionable drugs for TC treatment will also be provided.

Impact of Type 2 Diabetes Duration on the Efficacy and Safety of Add-on Lixisenatide in Asian Individuals Receiving Basal Insulin: A Pooled Analysis

INTRODUCTION

This analysis investigated the efficacy and safety of add-on lixisenatide by disease duration in Asian people with type 2 diabetes inadequately controlled with basal insulin ± oral antidiabetic drugs.

METHODS

Data for Asian participants in the GetGoal-Duo 1, GetGoal-L, and GetGoal-L-C studies were pooled and categorized by diabetes duration: < 10 years (group 1), 10 to < 15 years (group 2), and ≥ 15 years (group 3). Efficacy and safety of lixisenatide versus placebo were evaluated by subgroup. The potential influence of diabetes duration on efficacy was examined using multivariable regression analyses.

RESULTS

A total of 555 participants were included (mean age 53.9 years, 52.4% male). No significant differences in treatment effect between the duration subgroups were observed for the changes from baseline to 24 weeks in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial glucose (PPG), PPG excursion, body weight or body mass index, or the proportion of participants with HbA1c < 7% at 24 weeks (all P values for interaction > 0.1). Change in insulin dosage (U/day) was significantly different between subgroups (P = 0.038). Multivariable regression analysis showed participants in group 1 had a smaller change in body weight and basal insulin dose over the 24-week treatment period than participants in group 3 (P = 0.014 and 0.030, respectively) and were less likely to achieve an HbA1c < 7% than participants in group 2 (P = 0.047). No severe hypoglycemia was reported. A higher proportion of participants in group 3 versus the other groups had symptomatic hypoglycemia, for both lixisenatide and placebo, and T2D duration had a significant effect on hypoglycemia risk (P = 0.001).

CONCLUSIONS

Lixisenatide improved glycemic control in Asian individuals regardless of diabetes duration, without increasing the risk of hypoglycemia. Individuals with longer disease duration had a greater risk of symptomatic hypoglycemia than individuals with shorter disease duration regardless of treatment. No additional safety concerns were observed.

CLINICAL TRIAL REGISTRATION

GetGoal-Duo 1, ClinicalTrials.gov record NCT00975286; GetGoal-L, ClinicalTrials.gov record NCT00715624; GetGoal-L-C, ClinicalTrials.gov record NCT01632163.

An Investigation on the Efficacy of Glucagon-Like Peptide 1 Receptor Agonists Drugs in Reducing Urine Albumin-to-Creatinine Ratio in Patients With Type 2 Diabetes: A Potential Treatment for Diabetic Nephropathy

As diabetes mellitus becomes increasingly prevalent globally, so does diabetic nephropathy, a complication leading to one of the world's leading causes of end-stage renal disease (ESRD). Current research has linked an increase in the urine albumin-to-creatinine ratio (UACR), a marker for kidney damage, to a greater risk of adverse renal outcomes and ESRD in patients with diabetes. Of the diabetes medications studied and implemented in clinical settings, glucagon-like peptide-1 receptor agonist (GLP1-RA) drugs have been shown to not only help control HbA1c in diabetes but have also demonstrated numerous cardiovascular, hepatic, and renal benefits. The objective of our study was to assess the efficacy of GLP1-RA drugs in reducing UACR in patients with type 2 diabetes mellitus (T2 DM) to determine if GLP1-RAs could be used to provide renoprotection in diabetic nephropathy in addition to their glucose-lowering effects. Upon a comprehensive review of the literature, we conducted a statistical analysis to determine the efficacy of GLP1-RA monotherapy and combination therapy in reducing UACR in comparison to placebo and insulin glargine. Of the studies analyzed, GLP1-RAs exhibited a statistically significant effect in reducing UACR in comparison to a placebo but not in comparison to insulin glargine. GLP1-RA combination therapy (GLP1-RA used with either insulin glargine, metformin, or dapagliflozin) did not exhibit statistically significant UACR reductions in comparison with insulin glargine. However, GLP1-RA combination therapy showed a trend suggestive of being more effective than insulin glargine in reducing UACR, but due to the limited literature studying this treatment method, further studies in a more focused group of patients with diabetic nephropathy may produce stronger and more definitive results. GLP1-RA monotherapy or combination therapy has been determined to be an effective method for reducing UACR and decreasing the incidence of adverse renal outcomes associated with diabetic kidney disease. GLP1-RA therapy could serve as an alternative treatment in diabetic nephropathy to insulin glargine, which carries a higher risk of hypoglycemia and unintentional weight gain while potentially being less cost-effective.

The anti-inflammatory feature of glucagon-like peptide-1 and its based diabetes drugs—Therapeutic potential exploration in lung injury

Since 2005, GLP-1 receptor (GLP-1R) agonists (GLP-1RAs) have been developed as therapeutic agents for type 2 diabetes (T2D). GLP-1R is not only expressed in pancreatic islets but also other organs, especially the lung. However, controversy on extra-pancreatic GLP-1R expression still needs to be further resolved, utilizing different tools including the use of more reliable GLP-1R antibodies in immune-staining and co-immune-staining. Extra-pancreatic expression of GLP-1R has triggered extensive investigations on extra-pancreatic functions of GLP-1RAs, aiming to repurpose them into therapeutic agents for other disorders. Extensive studies have demonstrated promising anti-inflammatory features of GLP-1RAs. Whether those features are directly mediated by GLP-1R expressed in immune cells also remains controversial. Following a brief review on GLP-1 as an incretin hormone and the development of GLP-1RAs as therapeutic agents for T2D, we have summarized our current understanding of the anti-inflammatory features of GLP-1RAs and commented on the controversy on extra-pancreatic GLP-1R expression. The main part of this review is a literature discussion on GLP-1RA utilization in animal models with chronic airway diseases and acute lung injuries, including studies on the combined use of mesenchymal stem cell (MSC) based therapy. This is followed by a brief summary.

Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes Mellitus and Cardiovascular Disease: The Past, Present, and Future

Type 2 diabetes mellitus (T2DM) is associated with high cardiovascular morbidity and mortality, and cardiovascular diseases are the leading causes of death and disability in people with T2DM. Unfortunately, therapies strictly aimed at glycemic control have poorly contributed to a significant reduction in the risk of cardiovascular events. On the other hand, randomized controlled trials have shown that five glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and one exendin-based GLP-1 RA reduced atherosclerotic cardiovascular events in patients with diabetes at high cardiovascular risk. Furthermore, a meta-analysis including these six agents showed a reduction in major adverse cardiovascular events as well as all-cause mortality compared with placebo, regardless of structural homology. Evidence has also shown that some drugs in this class have beneficial effects on renal outcomes, such as preventing the onset of macroalbuminuria. In addition to lowering blood pressure, these drugs also favorably impacted on body weight in large randomized controlled trials as in real-world studies, a result considered a priority in T2DM management; these and other factors may justify the benefits of GLP-1 RAs upon the cardiovascular system, regardless of glycemic control. Finally, studies showed safety with a low risk of hypoglycemia and no increase in pancreatitis events. Given these benefits, GLP-1 RAs were preferentially endorsed in the guidelines of the European and American societies for patients with these conditions. This narrative review provides a current and comprehensive overview of GLP-1 RAs as cardiovascular and renal protective agents, far beyond their use as glucose-lowering drugs, supporting their effectiveness in treating patients with T2DM at high cardiovascular risk.

Toxicology of Medications for Diabetes Mellitus

Medications used to treat diabetes mellitus are heterogeneous, with widely differing safety profiles in therapeutic use and in overdose. Insulin overdose may produce severe and prolonged hypoglycemia. Sulfonylurea poisoning should be treated with octreotide, sparing intravenous dextrose where possible. Acute metformin overdose may lead to life-threatening acidosis with elevated lactate concentrations, which may require hemodialysis. Glucagon-like peptide 1 agonists and dipeptidyl peptidase 4 inhibitors are benign in overdose in diabetic patients but may produce profound hypoglycemia in nondiabetic patients. Euglycemic diabetic ketoacidosis may develop in critically ill patients taking sodium-glucose co-transporter 2 inhibitors.

Lixisenatide is effective and safe as add-on treatment to basal insulin in Asian individuals with type 2 diabetes and different body mass indices: a pooled analysis of data from the GetGoal Studies

INTRODUCTION

This analysis aims to investigate the efficacy and safety of once-daily lixisenatide add-on treatment to basal insulin in Asian individuals with type 2 diabetes, by baseline body mass index (BMI).

RESEARCH DESIGN AND METHODS

Data from all Asian participants in the placebo-controlled GetGoal-Duo 1, GetGoal-L, and GetGoal-L-C Studies were pooled and categorized according to the following BMI subgroups:<25 kg/m², 25-<30 kg/m² and ≥30 kg/m². Efficacy and safety of lixisenatide versus placebo were evaluated among BMI subgroups. Multivariable regression analyses were also conducted to explore the potential influence of BMI on efficacy outcomes after adjusting for baseline characteristics.

RESULTS

555 participants were included (mean age 53.9 years, 52.4% men). No significant differences in treatment effect between the BMI subgroups were observed for the changes from baseline to 24 weeks in glycated hemoglobin (HbA1c), fasting plasma glucose, postprandial glucose (PPG), PPG excursion, body weight, BMI, and basal insulin dose with lixisenatide, as well as the change in basal insulin dose at study endpoint and the proportion of participants achieving an HbA1c <7% at 24 weeks (all p values for interaction >0.15). In the multivariable regression analysis, participants in the lowest BMI group had a smaller reduction in body weight over the 24-week treatment period relative to the highest BMI group (p=0.023).

CONCLUSIONS

This post hoc analysis indicates that lixisenatide improved glycemic control regardless of baseline BMI and was well tolerated in Asian individuals unable to achieve their HbA1c target on basal insulin±oral antidiabetic drugs.

Diabetes and Its Complications: Therapies Available, Anticipated and Aspired

Worldwide, diabetes ranks among the ten leading causes of mortality. Prevalence of diabetes is growing rapidly in low and middle income countries. It is a progressive disease leading to serious co-morbidities, which results in increased cost of treatment and over-all health system of the country. Pathophysiological alterations in Type 2 Diabetes (T2D) progressed from a simple disturbance in the functioning of the pancreas to triumvirate to ominous octet to egregious eleven to dirty dozen model. Due to complex interplay of multiple hormones in T2D, there may be multifaceted approach in its management. The 'long-term secondary complications' in uncontrolled diabetes may affect almost every organ of the body, and finally may lead to multi-organ dysfunction. Available therapies are inconsistent in maintaining long term glycemic control and their long term use may be associated with adverse effects. There is need for newer drugs, not only for glycemic control but also for prevention or mitigation of secondary microvascular and macrovascular complications. Increased knowledge of the pathophysiology of diabetes has contributed to the development of novel treatments. Several new agents like Glucagon Like Peptide - 1 (GLP-1) agonists, Dipeptidyl Peptidase IV (DPP-4) inhibitors, amylin analogues, Sodium-Glucose transport -2 (SGLT- 2) inhibitors and dual Peroxisome Proliferator-Activated Receptor (PPAR) agonists are available or will be available soon, thus extending the range of therapy for T2D, thereby preventing its long term complications. The article discusses the pathophysiology of diabetes along with its comorbidities, with a focus on existing and novel upcoming antidiabetic drugs which are under investigation. It also dives deep to deliberate upon the novel therapies that are in various stages of development. Adding new options with new mechanisms of action to the treatment armamentarium of diabetes may eventually help improve outcomes and reduce its economic burden.

GLP-1 Receptor Agonists: Beyond Their Pancreatic Effects

Glucagon like peptide-1 (GLP-1) is an incretin secretory molecule. GLP-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes (T2DM) due to their attributes such as body weight loss, protection of islet β cells, promotion of islet β cell proliferation and minimal side effects. Studies have found that GLP-1R is widely distributed on pancreatic and other tissues and has multiple biological effects, such as reducing neuroinflammation, promoting nerve growth, improving heart function, suppressing appetite, delaying gastric emptying, regulating blood lipid metabolism and reducing fat deposition. Moreover, GLP-1RAs have neuroprotective, anti-infectious, cardiovascular protective, and metabolic regulatory effects, exhibiting good application prospects. Growing attention has been paid to the relationship between GLP-1RAs and tumorigenesis, development and prognosis in patient with T2DM. Here, we reviewed the therapeutic effects and possible mechanisms of action of GLP-1RAs in the nervous, cardiovascular, and endocrine systems and their correlation with metabolism, tumours and other diseases.

Exenatide once weekly decreases urinary albumin excretion in patients with type 2 diabetes and elevated albuminuria: Pooled analysis of randomized active controlled clinical trials

AIMS

To examine the albuminuria-lowering effect of exenatide once weekly (EQW) compared with active glucose-lowering comparators in patients with type 2 diabetes and elevated urinary albumin-to-creatinine ratio (uACR).

METHODS

Six randomized double-blind and open-label phase III studies were pooled in a post hoc, exploratory analysis to evaluate the efficacy and safety of EQW versus non-glucagon-like peptide-1 receptor agonist comparators in patients with type 2 diabetes and baseline uACR ≥30 mg/g. Treatment groups were EQW versus all comparators pooled. Efficacy outcomes were percent change from baseline to week 26/28 in uACR and absolute change in glycated haemoglobin (HbA1c), systolic blood pressure (SBP), body weight and estimated glomerular filtration rate (eGFR).

RESULTS

Baseline characteristics were generally similar between the two treatment groups (EQW: N = 194, all comparators: N = 274). Relative to the comparator group, EQW changed albuminuria by -26.2% (95% confidence interval [CI] -39.5 to -10). Similar improvements were observed with EQW versus oral glucose-lowering drugs (-29.6% [95% CI -47.6 to -5.3) or insulin (-23.8% [95% CI -41.8 to -0.2]). The effect of EQW on uACR was independent of baseline renin-angiotensin system inhibitor usage. Adjusted mean decreases in HbA1c, SBP and body weight were more pronounced in the EQW versus the comparator group. Adjustment for changes in HbA1c, eGFR and SBP did not substantially affect the uACR-lowering effect of EQW. When also adjusting for changes in body weight, the uACR-lowering effect was reduced to (-13.0% [95% CI -29.9 to 7.8]).

CONCLUSION

Exenatide once weekly reduced uACR in patients with type 2 diabetes and elevated albuminuria compared to commonly used glucose-lowering drugs.

Pharmacokinetic and dose-finding studies on efpeglenatide in patients with type 2 diabetes

AIM

To assess the efficacy, safety and pharmacokinetic/pharmacodynamic properties of efpeglenatide, a long-acting glucagon-like peptide-1 receptor agonist, in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Two randomized, double-blind, placebo-controlled phase 2 trials were conducted. The single-dose study (n = 48) was a first-in-patient, sequential dose-escalation study. Patients received a single subcutaneous injection of efpeglenatide (2-100 μg/kg) or placebo. The repeated-dose study (n = 71) was a multiple-ascending-dose trial. Patients received weekly (1, 2 or 4 mg once weekly; 8-week period) or monthly (8, 12 or 16 mg once monthly; 9-week period) subcutaneous injections of efpeglenatide or placebo (without titration).

RESULTS

Both studies demonstrated dose-proportional increases in efpeglenatide serum concentrations. The median time to attain maximum serum concentration (t_max ) for efpeglenatide ranged from 72 to 144 hours in the single-dose study and from 48 to 120 hours in the repeated-dose study (following final dose). Geometric mean t_1/2 ranged from 135 to 180 hours across studies. Peak-to-trough ratios in the repeated-dose study ranged from 1.3 to 1.4 with once-weekly dosing and from 5.9 to 12.9 with once-monthly dosing. Following a single dose of efpeglenatide 14-100 μg/kg, fasting plasma glucose and postprandial plasma glucose levels were decreased at week 1 and remained below baseline levels for ≥3 weeks post-dosing. Repeated doses of efpeglenatide led to significant reductions in glycated haemoglobin vs placebo. In both studies, efpeglenatide was generally well tolerated. Gastrointestinal disorders were the most frequently reported treatment-emergent adverse events in efpeglenatide-treated patients.

CONCLUSIONS

The delayed t_max, long half-life, and low peak-to-trough ratios observed demonstrate potential for improved efficacy and dosing flexibility, with good tolerability of efpeglenatide in patients with T2D.

Efficacy and safety of once-monthly efpeglenatide in patients with type 2 diabetes: Results of a phase 2 placebo-controlled, 16-week randomized dose-finding study

AIMS

To determine the optimal dose(s) of once-monthly administration of efpeglenatide, a long-acting glucagon-like peptide-1 receptor agonist (GLP-1RA), in patients with type 2 diabetes (T2D) inadequately controlled on metformin.

MATERIALS AND METHODS

In this phase 2, randomized, placebo-controlled, double-blind trial (NCT02081118), patients were randomized 1:1:1:1 to subcutaneous efpeglenatide (8, 12 or 16 mg once monthly; n = 158) or placebo (n = 51). The 16-week treatment period included a 4-week titration phase with once-weekly efpeglenatide 4 mg, followed by one dose of efpeglenatide 8 mg once monthly and two doses of the assigned once-monthly dose. The primary endpoint was change in glycated haemoglobin (HbA1c) from baseline to week 17.

RESULTS

All efpeglenatide doses significantly reduced HbA1c versus placebo (P < 0.0001 for all). Overall, the least squares mean difference in HbA1c reductions between efpeglenatide and placebo was -7.7 mmol/mol (-0.71%; baseline to week 17). At week 17, a significantly greater proportion of efpeglenatide patients had an HbA1c level <53 mmol/mol (<7%) versus placebo (48.7% vs. 30.6%; P = 0.0320). Significant body weight loss occurred across all efpeglenatide doses (placebo-corrected reduction -2.0 kg [efpeglenatide overall]; P = 0.0003). The safety profile was consistent with GLP-1RAs, with gastrointestinal (GI) disorders being the most common treatment-emergent adverse events. Fluctuations in effects on glucose levels and rates of GI events occurred between peak and trough efpeglenatide concentrations.

CONCLUSIONS

Efpeglenatide once monthly (following once-weekly titration) has significant benefits with regard to HbA1c and weight reduction versus placebo in patients with T2D. Further studies are needed to evaluate the long-term efficacy and safety of efpeglenatide once monthly.

Review: Diabetes, Obesity, and Cancer-Pathophysiology and Clinical Implications

Obesity and diabetes have both been associated with an increased risk of cancer. In the face of increasing obesity and diabetes rates worldwide, this is a worrying trend for cancer rates. Factors such as hyperinsulinemia, chronic inflammation, antihyperglycemic medications, and shared risk factors have all been identified as potential mechanisms underlying the relationship. The most common obesity- and diabetes-related cancers are endometrial, colorectal, and postmenopausal breast cancers. In this review, we summarize the existing evidence that describes the complex relationship between obesity, diabetes, and cancer, focusing on epidemiological and pathophysiological evidence, and also reviewing the role of antihyperglycemic agents, novel research approaches such as Mendelian Randomization, and the methodological limitations of existing research. In addition, we also describe the bidirectional relationship between diabetes and cancer with a review of the evidence summarizing the risk of diabetes following cancer treatment. We conclude this review by providing clinical implications that are relevant for caring for patients with obesity, diabetes, and cancer and provide recommendations for improving both clinical care and research for patients with these conditions.

Body weight management and safety with efpeglenatide in adults without diabetes: A phase II randomized study

AIM

To evaluate the safety of efpeglenatide, a long-acting glucagon-like peptide-1 receptor agonist (GLP-1RA), and its effects on body weight management in adults without diabetes.

MATERIALS AND METHODS

In this phase II, randomized, placebo-controlled, double-blind trial, participants with a body mass index (BMI) ≥30 kg/m² or ≥27 kg/m² with comorbidity were randomized 1:1:1:1:1 to efpeglenatide (4 mg once weekly, 6 mg once weekly, 6 mg once every 2 wk, or 8 mg once every 2 wk; n = 237) or placebo (n = 60) in combination with a hypocaloric diet. The primary endpoint was body weight change from baseline after 20 wk of treatment, assessed using a mixed-effect model with repeated measures with an unstructured covariance matrix over all post-screening visits; treatment comparisons were based on least squares mean estimates.

RESULTS

Over 20 wk, all doses of efpeglenatide significantly reduced body weight from baseline versus placebo (P < 0.0001), with placebo-adjusted reductions ranging between -6.3 kg (6 mg once every 2 wk) and -7.2 kg (6 mg once weekly). Greater proportions of efpeglenatide-treated participants had body weight loss of ≥5% or ≥10% versus placebo (P < 0.01, all comparisons). Efpeglenatide led to significant improvements in glycaemic variables (fasting plasma glucose and glycated haemoglobin) and lipid profiles (cholesterol, triglycerides) versus placebo. Rates of study discontinuations as a result of adverse events ranged from 5% to 19% with efpeglenatide. Gastrointestinal effects were the most common treatment-emergent adverse events.

CONCLUSIONS

Efpeglenatide once weekly and once every 2 wk led to significant body weight reduction and improved glycaemic and lipid variables versus placebo. It was also well tolerated for weight management in adults without diabetes.

Initial injectable therapy in type 2 diabetes: Key considerations when choosing between glucagon-like peptide 1 receptor agonists and insulin

Managing type 2 diabetes is complex and necessitates careful consideration of patient factors such as engagement in self-care, comorbidities and costs. Since type 2 diabetes is a progressive disease, many patients will require injectable agents, usually insulin. Recent ADA-EASD guidelines recommend glucagon-like peptide 1 receptor agonists (GLP-1 RAs) as first injectable therapy in most cases. The basis for this recommendation is the similar glycemic efficacy of GLP-1 RAs and insulin, but with GLP-1 RAs promoting weight loss instead of weight gain, at lower hypoglycemia risk, and with cardiovascular benefits in patients with pre-existing cardiovascular disease. GLP-1 RAs also reduce burden of glucose self-monitoring. However, tolerability and costs are important considerations, and notably, rates of drug discontinuation are often higher for GLP-1 RAs than basal insulin. To minimize risk of gastrointestinal symptoms patients should be started on lowest doses of GLP-1 RAs and up-titrated slowly. Overall healthcare costs may be lower with GLP-1 RAs compared to insulin. Though patient-level costs may still be prohibitive, GLP-1 RAs can replace 50-80 units of insulin daily and reduce costs associated with glucose self-monitoring. Decisions regarding initiating injectable therapy should be individualized. This review provides a framework to guide decision-making in the real-world setting.

Comparison of ELISA and HPLC-MS methods for the determination of exenatide in biological and biotechnology-based formulation matrices

The development of biotechnology-based active pharmaceutical ingredients, such as GLP-1 analogs, brought changes in type 2 diabetes treatment options. For better therapeutic efficiency, these active pharmaceutical ingredients require appropriate administration, without the development of adverse effects or toxicity. Therefore, it is required to develop several quantification methods for GLP-1 analogs products, in order to achieve the therapeutic goals, among which ELISA and HPLC arise. These methods are developed, optimized and validated in order to determine GLP-1 analogs, not only in final formulation of the active pharmaceutical ingredient, but also during preclinical and clinical trials assessment. This review highlights the role of ELISA and HPLC methods that have been used during the assessment for GLP-1 analogs, especially for exenatide.

Change in HbA1c Across the Baseline HbA1c Range in Type 2 Diabetes Patients Receiving Once-Weekly Dulaglutide Versus Other Incretin Agents

INTRODUCTION

This exploratory post hoc analysis investigated the relative changes in glycated haemoglobin (HbA_1c) in patients with type 2 diabetes mellitus (T2DM) treated with dulaglutide versus active comparators across a continuous range of baseline HbA_1c values using data from three phase III randomised controlled trials.

METHODS

Data from patients receiving once-weekly dulaglutide 0.75 and 1.5 mg, once-daily sitagliptin 100 mg, once-daily liraglutide 1.8 mg or twice-daily exenatide 10 μg in the intent-to-treat populations in the AWARD-5, AWARD-6 and AWARD-1 trials were analysed using last observation carried forward analysis of covariance. Starting with the predefined statistical model from each study, the type of association between HbA_1c baseline and change at 26 weeks was modelled. Consistency of treatment effect was assessed via treatment-by-baseline HbA_1c interaction terms.

RESULTS

Improvements in HbA_1c occurred in all treatment groups across the entire baseline HbA_1c range. The relationship between HbA_1c baseline and magnitude of change was linear in all treatment groups, with greater reductions in patients with higher baseline HbA_1c values. Across the continuum of baseline HbA_1c values, patients treated with dulaglutide 1.5 mg achieved a similar mean HbA_1c reduction to patients receiving liraglutide 1.8 mg and a greater reduction than patients receiving twice-daily exenatide or sitagliptin. In AWARD-5, the treatment-by-baseline HbA_1c interaction P value (0.001) demonstrated progressively greater HbA_1c reduction in dulaglutide-treated compared with sitagliptin-treated patients as baseline HbA_1c increased.

CONCLUSION

Our results suggest that dulaglutide is an appropriate therapeutic option for patients with T2DM across a wide range of baseline HbA_1c values, including those with poor metabolic control.

FUNDING

Eli Lilly and Company. Plain language summary available for this article.

Bacterial Protein Mimetic of Peptide Hormone as a New Class of Protein- based Drugs

Specific peptide molecules classified as hormones, neuropeptides and cytokines are involved in intercellular signaling regulating various physiological processes in all organs and tissues. This justifies the peptidergic signaling as an attractive pharmacological target. Recently, a protein mimetic of a peptide hormone has been identified in Escherichia coli suggesting the potential use of specific bacterial proteins as a new type of peptide-like drugs. We review the scientific rational and technological approaches leading to the identification of the E. coli caseinolytic protease B (ClpB) homologue protein as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a melanocortin peptide critically involved in the regulation of energy homeostasis in humans and animals. Theoretical and experimental backgrounds for the validation of bacterial ClpB as a potential drug are discussed based on the known E. coli ClpB amino acid sequence homology with α-MSH. Using in silico analysis, we show that other protein sources containing similar to E. coli ClpB α-MSH-like epitopes with potential biological activity may exist in Enterobacteriaceae and in some Brassicaceae. Thus, the original approach leading to the identification of E. coli ClpB as an α-MSH mimetic protein can be applied for the identification of mimetic proteins of other peptide hormones and development of a new type of peptide-like protein-based drugs.

The Role of Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes in Asia

The improvement of glycemic control in patients with type 2 diabetes (T2D) is an urgent need in Asia. East Asian T2D patients have distinct characteristics, including relatively low body weight, early impairment of islet beta cell function with reduced insulin secretion and a marked increase in postprandial blood glucose levels. Control of postprandial hyperglycemia and beta cell preservation are key elements of the therapeutic strategy for these patients. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduce HbA1c, fasting plasma glucose, and (in particular) postprandial glucose levels, and slow gastric emptying, while minimizing the risk of hypoglycemia and weight gain. Compared with long-acting GLP-1RAs, short-acting GLP-1RAs produce greater slowing of gastric emptying (which is a key factor driving the reduction of postprandial glycemia) and induce beta cell rest rather than promoting postprandial insulin secretion when used under physiological conditions. GLP-1RAs have greater efficacy in Asian than Caucasian patients. GLP-1RA add-on therapy provides clinically meaningful reductions in HbA1c and postprandial glucose in Asians with T2D inadequately controlled by oral antidiabetic drugs (OADs) or basal insulin ± OADs. Premixed insulin is often prescribed for T2D patients in China. A short-acting GLP-1RA plus basal insulin is an alternative to premixed insulin, resulting in better efficacy and a lower risk of hypoglycemia and weight gain. In conclusion, GLP-1RAs, especially short-acting GLP-1RAs, are a practical treatment option for East Asian patients with T2D inadequately controlled by OADs or basal insulin.Funding: Sanofi.

Structural Modeling and in Silico Screening of Potential Small-Molecule Allosteric Agonists of a Glucagon-like Peptide 1 Receptor

The glucagon-like peptide 1 receptor (GLP-1R) belongs to the pharmaceutically important class B family of G-protein-coupled receptors (GPCRs), and its incretin peptide ligand GLP-1 analogs are adopted drugs for the treatment of type 2 diabetes. Despite remarkable antidiabetic effects, GLP-1 peptide-based drugs are limited by the need of injection. On the other hand, developing nonpeptidic small-molecule drugs targeting GLP-1R remains elusive. Here, we first constructed a three-dimensional structure model of the transmembrane (TM) domain of human GLP-1R using homology modeling and conformational sampling techniques. Next, a potential allosteric binding site on the TM domain was predicted computationally. In silico screening of druglike compounds against this predicted allosteric site has identified nine compounds as potential GLP-1R agonists. The independent agonistic activity of two compounds was subsequently confirmed using a cAMP response element-based luciferase reporting system. One compound was also shown to stimulate insulin secretion through in vitro assay. In addition, this compound synergized with GLP-1 to activate human GLP-1R. These results demonstrated that allosteric regulation potentially exists in GLP-1R and can be exploited for developing small-molecule agonists. The success of this work will help pave the way for small-molecule drug discovery targeting other class B GPCRs through allosteric regulations.

Effect of incretin-based therapies on cancers of digestive system among 101 595 patients with type 2 diabetes mellitus: a systematic review and network meta-analysis combining 84 trials with a median duration of 30 weeks

OBJECTIVES

To evaluate the risk of cancers of digestive system with incretin-based therapies among patients with type 2 diabetes mellitus.

RESEARCH DESIGN AND METHODS

Medline, Embase, Cochrane Library and ClinicalTrials.gov databases were searched for randomized controlled clinical trials that compared incretin-based drugs with placebo or other antidiabetic drugs. Paired reviewers independently screened citations, extracted data and assessed risk of bias of included studies. Network meta-analysis was performed, followed by subgroup analysis. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence.

RESULTS

A total of 84 studies (n=101 595) involving cancers of digestive system were identified (a median follow-up of 30 weeks). The risk of cancers of digestive system with incretin-based therapies was comparable with insulin (OR: 0.86, 95% CI 0.27 to 2.69), metformin (OR: 0.32, 95% CI 0.07 to 1.38), sodium-glucose co-transporter 2 (OR: 5.26, 95% CI 0.58 to 47.41), sulfonylureas (OR: 1.27, 95% CI 0.68 to 2.39), thiazolidinediones (OR: 0.42, 95% CI 0.13 to 1.42), alpha-glucosidase inhibitors (OR: 2.98, 95% CI 0.12 to 73.80), and placebo (OR: 0.87, 95% CI 0.71 to 1.05). The results of subgroup analysis based on the type of digestive system cancers indicated that incretin-based therapies did not increase the risk of gastrointestinal cancers, respectively. The results of subgroup analysis based on age, duration, mean HbA1c, trial duration, and sample size did not indicate the risk of digestive system cancers.

CONCLUSIONS

Moderate to high Grading of Recommendations Assessment, Development and Evaluation evidence suggests that incretin-based therapies were not associated with an increased risk of cancer of digestive system in patients with type 2 diabetes mellitus.

Exenatide has a pronounced effect on energy intake but not energy expenditure in non-diabetic subjects with obesity: A randomized, double-blind, placebo-controlled trial

AIMS

Exenatide is a glucagon-like peptide 1 (GLP-1) mimetic which induces weight loss predominantly, it is presumed, via decreased food intake. However, circulating GLP-1 is also a determinant of energy expenditure. We sought to quantify the effect of exenatide on energy expenditure (EE) and energy intake.

MATERIALS AND METHODS

In this single-center, randomized double-blind placebo controlled trial, we randomized 80 healthy, non-diabetic volunteers with obesity (46 women, age: 34.4 ± 8.7 y, body fat by DXA: 44.2 ± 7.8%) to subcutaneous exenatide 10 μg twice daily or placebo. Subjects were admitted to our clinical research unit for measurement of 24 h-EE in a whole-room indirect calorimeter and ad libitum food intake using an automated vending machine paradigm before and after randomization. Furthermore, energy expenditure and ad libitum food intake measures were repeated at 24-week after readmission for 7-day inpatient stay. Body weight was obtained weekly for up to 5 weeks and was recorded at each monthly follow up visit up to 24 weeks.

RESULTS

Prior to randomization, participants over ate during the 3-day vending machine period in the whole study group (114.6 ± 35.2%), expressed as percentage of weight maintaining energy needs (WMEN) with those who were eventually randomized to exenatide overeating more (121.6 ± 37.7%) compared to placebo group (107.6 ± 31.5%). In the exenatide group, ad libitum absolute energy intake decreased by 1016.1 ± 724.5 kcal/day (95% CI: -1250.9 to -781.2) versus a 245.1 ± 710.5 kcal/day (95% CI: -475.4 to -14.7) decrease in placebo (Δ = -624.8 Kcal/day, p < 0.0001) whereas the reduction in ad libitum caloric intake relative to WMEN was a more modest 366.8 ± 752.1 kcal/day (95% CI: -614.0 to -119.6) decrease compared to 8.0 ± 860.1 kcal/day (95% CI: -286.8 to 270.8) reduction in placebo (Δ = -382.3 Kcal/day, p = 0.03). The decrease was uniform across all macronutrients groups. No differences in 24hEE or substrate oxidation rates were found. In the exenatide group, body weight decreased more over the 5 weeks (β = -0.039 kg/week, p = 0.02) and was lower compared to placebo at the end of fifth week (-1.48 ± 0.77 kg; 95% CI: -3.02 to 0.05, p = 0.06). At the 24-week follow up, there was no difference in energy intake between exenatide group and placebo group and the treatment group decreased 24-h EE more compared to placebo (β = -160.6 Kcal/day, 95% CI: -307.6 to 13.6, p = 0.03) compared to their pre-randomization measurement. However, this reduction was not present after adjustment for changes in FM and FFM (β = -87 kcal/day, p = 0.14). No difference was observed in body weight (Δ = -1.72 kg, 95% CI: -5.77 to 2.30, p = 0.39) in exenatide versus placebo over 24 weeks.

CONCLUSION

Compared with placebo, exenatide decreased early ad libitum energy intake but did not change 24 h-EE. However, the reduction was more modest in relative versus absolute terms (i.e. below that needed for WMEN). Thus, although rate of weight change was greater in the exenatide treated subjects at 5 weeks, the absolute difference in weight was not significant. These findings indicate that although exenatide reduces food intake, it may be more beneficial in blunting overeating and thus may serve to more prevent weight regain following initial weight loss.

Synergistic anti-tumor effects of liraglutide with metformin on pancreatic cancer cells

Either metformin or liraglutide has been reported to have anti-tumor effects on pancreatic cancer cells. However, it is not clear whether their combined treatment has additive or synergistic anti-tumor effects on pancreatic cancer cells. In this study, the human pancreatic cancer cell line MiaPaca-2 was incubated with liraglutide and/or metformin. The cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and wound-healing and transwell migration assays were used to detect cell viability, clonogenic survival, cell cycle and cell migration, respectively. RT-PCR and western blot analyses were used to determine the mRNA and protein levels of related molecules. Results showed that combination treatment with liraglutide (100 nmol/L) and metformin (0.75 mmol/L) significantly decreased cell viability and colony formation, caused cell cycle arrest, upregulated the level of pro-apoptotic proteins Bax and cleaved caspase-3, and inhibited cell migration in the cells, although their single treatment did not exhibit such effects. Combination index value for cell viability indicated a synergistic interaction of liraglutide and metformin. Moreover, the combined treatment with liraglutide and metformin could activate the phosphorylation of AMP-activated protein kinase (AMPK) more potently than their single treatment in the cells. These results suggest that liraglutide in combination with metformin has a synergistic anti-tumor effect on the pancreatic cancer cells, which may be at least partly due to activation of AMPK signaling. Our study provides new insights into the treatment of patients with type 2 diabetes and pancreatic cancer.

Allostery and Biased Agonism at Class B G Protein-Coupled Receptors

Class B G protein-coupled receptors (GPCRs) respond to paracrine or endocrine peptide hormones involved in control of bone homeostasis, glucose regulation, satiety, and gastro-intestinal function, as well as pain transmission. These receptors are targets for existing drugs that treat osteoporosis, hypercalcaemia, Paget's disease, type II diabetes, and obesity and are being actively pursued as targets for numerous other diseases. Exploitation of class B receptors has been limited by difficulties with small molecule drug discovery and development and an under appreciation of factors governing optimal therapeutic efficacy. Recently, there has been increasing awareness of novel attributes of GPCR function that offer new opportunity for drug development. These include the presence of allosteric binding sites on the receptor that can be exploited as drug binding pockets and the ability of individual drugs to enrich subpopulations of receptor conformations to selectively control signaling, a phenomenon termed biased agonism. In this review, current knowledge of biased signaling and small molecule allostery within class B GPCRs is discussed, highlighting areas that have progressed significantly over the past decade, in addition to those that remain largely unexplored with respect to these phenomena.