Review of head-to-head comparisons of glucagon-like peptide-1 receptor agonists

Cardiovascular Effects of Different GLP-1 Receptor Agonists in Patients with Type 2 Diabetes

PURPOSE OF REVIEW

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have positive effects on weight loss, blood pressure, hyperlipidemia, and glycemic control. They exhibit a broad range of effects on the cardiovascular system that are independent of changes in blood glucose. Cardiovascular outcome trials have demonstrated safety of GLP-1 RAs but results for cardiovascular efficacy were varied. The aim of the present review is the assessment of the effects of GLP-1 RAs on cardiovascular risk factors, and major cardiovascular events.

RECENT FINDINGS

Use of GLP-1 RAs was associated with relative risk reduction in cardiovascular mortality and all-cause mortality with no significant differences for the incidence of severe hypoglycemia, pancreatitis, pancreatic cancer, or medullary thyroid cancer when compared to placebo. Although there are differences between individual medications with respect to their effects on cardiovascular events, GLP-1 RAs offer a favorable risk-benefit profile. The present review confirms the cardiovascular safety and efficacy vs placebo of GLP-1 RAs in patients with type 2 diabetes at moderate-to-high atherosclerotic cardiovascular risk without significant side effects. Although professional guidelines recommend metformin as the sole first-line agent, GLP-1 RAs can be used as first-line therapy in individuals with type 2 diabetes who either are intolerant to metformin or have high cardiovascular risk factors.

Cardiovascular benefits of GLP-1 agonists in type 2 diabetes: a comparative review

Type 2 diabetes (T2D) carries risks of both cardiovascular (CV) (myocardial infarction, stroke, and peripheral vascular disease) and microvascular (retinopathy/nephropathy/neuropathy) complications. Glucose-lowering is an effective strategy for preventing microvascular complications, but the extent to which it can reduce CV complications is less certain. Glucagon-like peptide-1 (GLP-1) agonists are potent glucose-lowering agents but also have potentially beneficial effects on other traditional (body weight, blood pressure (BP), and LDL cholesterol) and non-traditional risk factors (low grade inflammation and endothelial dysfunction). The results of four large CV outcome trials with GLP-1 agonists are now available. These have compared lixisenatide (ELIXA), liraglutide (LEADER), semaglutide (SUSTAIN-6), and long-acting exenatide (EXSCEL) with placebo and standard of care over 2–4 years; four others (including with dulaglutide and albiglutide) are ongoing. LEADER and SUSTAIN-6 have demonstrated reductions in rates of major adverse CV events with active GLP-1 treatment but ELIXA and EXSCEL have not. In this review, we discuss the mechanisms by which GLP-1 receptor agonists act on the CV system and the design and conduct of these trials. Contrary to the assertions that (a) all GLP-1 agonists reduce CV disease in T2D but to different extents or (b) the magnitude of CV protection is predominantly related to glucose-lowering, we argue that CV benefit is specific to agents that provide longer acting agonism at the GLP-1 receptor. The mechanisms involve reduction in body weight and BP, and lowering of LDL-cholesterol and glucose, but pleiotropic effects—including suppression of low grade inflammation, vasodilation, and natriuresis—are also likely relevant.

Effect of once weekly dulaglutide by baseline beta-cell function in people with type 2 diabetes in the AWARD programme

Glucagon-like peptide-1 receptor agonists lower blood glucose in type 2 diabetes (T2D) partially through glucose-dependent stimulation of insulin secretion. The aim of this study was to investigate whether beta-cell function (as measured by HOMA2-%B) at baseline affects the glycaemic response to dulaglutide. Dulaglutide-treated patients from AWARD-1, AWARD-3 and AWARD-6 clinical studies were categorised based on their homeostatic model assessment of beta-cell function (HOMA2-%B) tertiles. Changes in glycaemic measures in response to treatment with once-weekly dulaglutide were evaluated in each HOMA2-%B tertile. Patients with low HOMA2-%B had higher baseline glycated haemoglobin (HbA1c), fasting and postprandial blood glucose, and longer duration of diabetes (P < .001, all) (mean low, middle and high tertiles with dulaglutide 1.5 mg: HOMAB-2%B, 31%, 58%, 109%; HbA1c, 8.7%, 7.7%, 7.3%, respectively). At 26 weeks, the low tertile experienced larger reductions in HbA1c compared to the high tertile with dulaglutide 1.5 mg (mean; -1.55% vs. -0.98% [-16.94 vs. -10.71 mmol/mol]). Differences between low and high tertiles disappeared when adjusted for baseline HbA1c (LSM; -1.00 vs. -1.18% [-10.93 vs. -12.90 mmol/mol]). Greater decreases in fasting blood glucose and greater increases in fasting C-peptide were observed in the low tertile. Similar increases in HOMA2-%B were observed in all tertiles. Dulaglutide demonstrated clinically relevant HbA1c reduction irrespective of estimated baseline beta-cell function.

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.

Plausibility criteria for putative pathophysiological mechanisms in functional gastrointestinal disorders: a consensus of experts

BACKGROUND AND AIMS

The functional gastrointestinal disorders (FGIDs) are extremely common conditions associated with a considerable personal, social and health economic burden. Managing FGIDs in clinical practice is challenging because of the uncertainty of symptom-based diagnosis, the high frequency of overlap between these conditions and the limited efficacy of available therapies. It has often been argued that successful drug development and management of FGIDs requires knowledge of the underlying pathophysiology. Numerous and highly variable candidate pathophysiological mechanisms have been implicated in the generation of FGID symptoms, but there is no current consensus on how to best define the relevance of these disturbances.

METHODS

A group of international experts on FGIDs developed plausibility criteria that should be fulfilled by relevant pathophysiological mechanisms in FGIDs.

RESULTS

Five criteria are proposed: (1) the presence of the abnormality in a subset of patients, (2) temporal association between proposed mechanism and symptom(s), (3) correlation between the level of impairment of the mechanism and symptom(s), (4) induction of the symptom(s) by provoking the pathophysiological abnormality in healthy subjects and (5) treatment response by a therapy specifically correcting the underlying disorder or congruent natural history of symptoms and dysfunction in the absence of specific therapy. Based on strength of evidence for these five criteria according to the Grading of Recommendations Assessment, Development and Evaluation system, a plausibility score can be calculated for each mechanism.

CONCLUSION

Evaluation of the strength of evidence for candidate pathophysiological abnormalities fulfilling these five plausibility criteria will help to identify the most relevant mechanisms to target for novel diagnostic approaches and for the development of new therapies.

Chemical Strategies for Half-Life Extension of Biopharmaceuticals: Lipidation and Its Alternatives

Strategies for half-life extension are often required in the design of new biopharmaceuticals. This Viewpoint focuses on chemical moieties that convey protraction by albumin binding or by self-assembly to form larger structures, with GLP-1 and insulin as examples.

Patients with Obesity Caused by Melanocortin-4 Receptor Mutations Can Be Treated with a Glucagon-like Peptide-1 Receptor Agonist

Pathogenic mutations in the appetite-regulating melanocortin-4 receptor (MC4R) represent the most common cause of monogenic obesity with limited treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) cause weight loss by reducing appetite. We assessed the effect of the GLP-1 RA liraglutide 3.0 mg for 16 weeks in 14 obese individuals with pathogenic MC4R mutations (BMI 37.5 ± 6.8) and 28 matched control participants without MC4R mutation (BMI 36.8 ± 4.8). Liraglutide decreased body weight by 6.8 kg ± 1.8 kg in individuals with pathogenic MC4R mutations and by 6.1 kg ± 1.2 kg in control participants. Total body fat, waist circumference, and fasting and postprandial glucose concentrations similarly decreased in both groups. Thus, liraglutide induced an equal, clinically significant weight loss of 6% in both groups, indicating that the appetite-reducing effect of liraglutide is preserved in MC4R causal obesity and that liraglutide acts independently of the MC4R pathway. Thus, liraglutide could be an effective treatment of the most common form of monogenic obesity.

Glucagon-like peptide 1 in health and disease

In healthy individuals, the incretin hormone glucagon-like peptide 1 (GLP1) potentiates insulin release and suppresses glucagon secretion in response to the ingestion of nutrients. GLP1 also delays gastric emptying and increases satiety. In patients with type 2 diabetes mellitus (T2DM), supraphysiological doses of GLP1 normalize the endogenous insulin response during a hyperglycaemic clamp. Owing to the short plasma half-life of native GLP1, several GLP1 receptor agonists (GLP1RAs) with longer half-lives have been developed for the treatment of T2DM. These compounds vary in chemical structure, pharmacokinetics and size, which results in different clinical effects on hyperglycaemia and body weight loss; these variations might also explain the difference in cardiovascular effect observed in large-scale cardiovascular outcome trials, in which certain GLP1RAs were shown to have a positive effect on cardiovascular outcomes. Owing to their metabolic effects, GLP1RAs are also considered for the treatment of several other lifestyle-induced conditions, such as obesity, prediabetes and liver disease. This Review provides insights into the physiology of GLP1 and its involvement in the pathophysiology of T2DM and an overview of the currently available and emerging GLP1RAs. Furthermore, we review the results from the currently available large-scale cardiovascular outcome trials and the use of GLP1RAs for other indications.

Semaglutide: The Newest Once-Weekly GLP-1 RA for Type 2 Diabetes

OBJECTIVE

To review efficacy and safety of the glucagon-like peptide-1 receptor agonist (GLP-1 RA) semaglutide for type 2 diabetes (T2D).

DATA SOURCES

A literature search of PubMed/MEDLINE and EMBASE using the term semaglutide was completed through April 2018. A search of clinicaltrials.gov was also conducted.

STUDY SELECTION AND DATA EXTRACTION

English-language studies assessing the efficacy and/or safety of semaglutide were evaluated.

DATA SYNTHESIS

Semaglutide is a newly approved GLP-1 RA for the treatment of T2D. Administered once weekly at a dose of 0.5 or 1 mg, it has been compared with placebo, sitagliptin, insulin glargine, a combination of oral antidiabetic therapies, and 2 GLP-1 RAs, exenatide ER and dulaglutide, and demonstrated greater efficacy compared with these therapies. Published data from studies ranging from 30 to 104 weeks duration demonstrate efficacy with decreases in hemoglobin A1C (A1C) ranging from 1.1% to 2.2%. Studies show reductions in weight from 1.4 to 6.5 kg. Semaglutide demonstrated a reduction in the composite outcome of cardiovascular (CV) death, nonfatal myocardial infarction, or nonfatal stroke compared with placebo in patients at high risk of CV events (hazard ratio = 0.74; P = 0.02). Common adverse effects include nausea, vomiting, and diarrhea as seen with other GLP-1 RAs. Relevance to Patient Care and Clinical Practice: Semaglutide represents an attractive GLP-1 RA considering its A1C and weight reduction. It provides patient convenience and high patient satisfaction.

CONCLUSIONS

Semaglutide is an appealing option for the treatment of T2D as a once-weekly GLP-1 RA with established glycemic, CV, and weight benefits.

Molecular Mechanisms Underlying the Cardiovascular Benefits of SGLT2i and GLP-1RA

PURPOSE OF REVIEW

In addition to their effects on glycemic control, two specific classes of relatively new anti-diabetic drugs, namely the sodium glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have demonstrated reduced rates of major adverse cardiovascular events (MACE) in subjects with type 2 diabetes (T2D) at high risk for cardiovascular disease (CVD). This review summarizes recent experimental results that inform putative molecular mechanisms underlying these benefits.

RECENT FINDINGS

SGLT2i and GLP-1RA exert cardiovascular effects by targeting in both common and distinctive ways (A) several mediators of macro- and microvascular pathophysiology: namely (A1) inflammation and atherogenesis, (A2) oxidative stress-induced endothelial dysfunction, (A3) vascular smooth muscle cell reactive oxygen species (ROS) production and proliferation, and (A4) thrombosis. These agents also exhibit (B) hemodynamic effects through modulation of (B1) natriuresis/diuresis and (B2) the renin-angiotensin-aldosterone system. This review highlights that while GLP-1RA exert direct effects on vascular (endothelial and smooth muscle) cells, the effects of SGLT2i appear to include the activation of signaling pathways that prevent adverse vascular remodeling. Both SGLT2i and GLP-1RA confer hemodynamic effects that counter adverse cardiac remodeling.

Semaglutide: Review and Place in Therapy for Adults With Type 2 Diabetes

Guidelines increasingly highlight the importance of multifactorial management in type 2 diabetes, in contrast to the more traditional focus on glycemic control. Semaglutide, a recently approved glucagon-like peptide-1 receptor agonist, is indicated in Canada for adults with type 2 diabetes to improve glycemic control as monotherapy with diet and exercise when metformin is inappropriate or as an add-on to either metformin alone or metformin plus a sulfonylurea or basal insulin. The Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes (SUSTAIN) clinical trial program for semaglutide comprises 6 pivotal global phase 3a trials (SUSTAIN 1 through 6) and 2 Japanese phase 3a trials. Phase 3b trials include SUSTAIN 7, and SUSTAIN 8 and 9 (both ongoing). Results from the completed trials support the superiority of semaglutide for reduction of glycated hemoglobin levels and weight loss vs. placebo as well as active comparators, including sitagliptin, exenatide extended-release, dulaglutide and insulin glargine. SUSTAIN 6 trial data confirmed cardiovascular safety and demonstrated significant reductions in major cardiovascular events with semaglutide vs. placebo, an outcome that confirmed the noninferiority of semaglutide. The robust and sustained effects of semaglutide on glycated hemoglobin levels and weight loss vs. comparators, as well as its safety and possible cardiovascular benefit, address an unmet need in the treatment of type 2 diabetes. This article overviews data from across the semaglutide clinical trial program, including efficacy and safety results and findings from post hoc analyses. The potential place of semaglutide in clinical practice is discussed.

Semaglutide Added to Basal Insulin in Type 2 Diabetes (SUSTAIN 5): A Randomized, Controlled Trial

CONTEXT

Combination therapy with insulin and glucagon-like peptide-1 receptor agonists (GLP-1RAs) is important for treating type 2 diabetes (T2D). This trial assesses the efficacy and safety of semaglutide, a GLP-1RA, as an add-on to basal insulin.

OBJECTIVE

To demonstrate the superiority of semaglutide vs placebo on glycemic control as an add-on to basal insulin in patients with T2D.

DESIGN

Phase 3a, double-blind, placebo-controlled, 30-week trial.

SETTING

This study included 90 sites in five countries.

PATIENTS

We studied 397 patients with uncontrolled T2D receiving stable therapy with basal insulin with or without metformin.

INTERVENTIONS

Subcutaneous semaglutide 0.5 or 1.0 mg once weekly or volume-matched placebo.

MAIN OUTCOME MEASURES

Primary endpoint was change in glycated Hb (HbA1c) from baseline to week 30. Confirmatory secondary endpoint was change in body weight from baseline to week 30.

RESULTS

At week 30, mean HbA1c reductions [mean baseline value, 8.4% (67.9 mmol/mol)] with semaglutide 0.5 and 1.0 mg were 1.4% (15.8 mmol/mol) and 1.8% (20.2 mmol/mol) vs 0.1% (1.0 mmol/mol) with placebo [estimated treatment difference (ETD) vs placebo, -1.35 (14.8 mmol/mol); 95% CI, -1.61 to -1.10 and ETD, -1.75% (19.2 mmol/mol); 95% CI, -2.01 to -1.50; both P < 0.0001]. Severe or blood glucose-confirmed hypoglycemic episodes were reported in 11 patients (17 events) and 14 patients (25 events) with semaglutide 0.5 and 1.0 mg, respectively, vs seven patients (13 events) with placebo (estimated rate ratio vs placebo, 2.08; 95% CI, 0.67 to 6.51 and estimated rate ratio vs placebo, 2.41; 95% CI, 0.84 to 6.96 for 0.5 and 1.0 mg; both P = nonsignificant). Mean body weight decreased with semaglutide 0.5 and 1.0 mg vs placebo from baseline to end of treatment: 3.7, 6.4, and 1.4 kg (ETD, -2.31; 95% CI, -3.33 to -1.29 and ETD, -5.06; 95% CI, -6.08 to -4.04 kg; both P < 0.0001). Premature treatment discontinuation due to adverse events was higher for semaglutide 0.5 and 1.0 mg vs placebo (4.5%, 6.1%, and 0.8%), mainly due to gastrointestinal disorders.

CONCLUSIONS

Semaglutide, added to basal insulin, significantly reduced HbA1c and body weight in patients with uncontrolled T2D vs placebo.

Pharmacokinetics and tolerability of semaglutide in people with hepatic impairment

AIMS

To investigate whether the pharmacokinetic characteristics of semaglutide were altered in people with hepatic impairment, assessed using Child-Pugh criteria, vs those with normal hepatic function.

METHODS

In this multicentre, open-label, parallel-group trial (sponsor Novo Nordisk, ClinicalTrials.gov ID NCT02210871), four groups of participants with normal hepatic function (n = 19) or mild (n = 8), moderate (n = 10) or severe (n = 7) hepatic impairment received a single, subcutaneous dose of 0.5 mg semaglutide. Semaglutide plasma concentrations were assessed frequently for 35 days after dosing. The primary endpoint was area under the semaglutide plasma concentration-time curve from time zero to infinity (AUC_0-∞ ). No effect of hepatic impairment was declared if the 90% confidence interval (CI) for the between-group ratio (hepatic impairment/normal function) was within the interval 0.70 to 1.43.

RESULTS

Semaglutide exposure was similar across all groups, with AUC_0-∞ treatment ratios for mild impairment/normal function of 0.95 (90% CI 0.77, 1.16), moderate impairment/normal function 1.02 (90% CI 0.93, 1.12), and severe impairment/normal function 0.97 (90% CI 0.84, 1.12). The maximum plasma semaglutide concentration (C_max ) did not appear to be influenced by hepatic function, with mild impairment/normal function treatment ratios of 0.99 (90% CI 0.80, 1.23), moderate impairment/normal function 1.02 (90% CI 0.88, 1.18) and severe impairment/normal function 1.15 (90% CI 0.89, 1.48; sensitivity analysis excluding one extreme semaglutide concentration: 1.05 [90% CI 0.88, 1.25]). In all, 10 participants reported 12 mild or moderate non-serious adverse events. No unexpected safety or tolerability issues were observed.

CONCLUSIONS

Semaglutide exposure did not appear to be affected by hepatic impairment, suggesting that dose adjustment may not be necessary in patients with hepatic impairment. Semaglutide was well tolerated and there were no unexpected safety issues.

Glucagon-like Peptide-1 Receptor Agonists and Cardiovascular Events: Class Effects versus Individual Patterns

Several new glucose-lowering medications have been approved, such as dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs), and sodium glucose cotransporter-2 inhibitors. Among GLP-1RAs, lixisenatide, a short-acting drug, did not show cardiovascular (CV) benefits in patients with Type 2 diabetes mellitus (T2D) and acute coronary syndrome. Extended-release exenatide was also not significantly better for CV outcomes. By contrast, once daily liraglutide and once weekly semaglutide, both long-acting GLP-1RAs, decreased the incidence of major adverse CV events and mortality. This Review attempts to explain favorable CV results with some, but not all, GLP-1RAs, to aid in their differential prescription with the aim of further reducing the adverse CV burden of T2D.

Newer GLP-1 receptor agonists and obesity-diabetes

Obesity is a major risk factor for type 2 diabetes and may complicate type 1 diabetes. In parallel with the global epidemic of obesity, the incidence of type 2 diabetes is increasing exponentially. To reverse these alarming trends, weight loss becomes a major therapeutic priority in prevention and treatment of type 2 diabetes. Given that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) improve glycaemic control and cause weight loss, they are receiving increasing attention for the treatment of diabetes-obesity. This review discusses current and emerging therapeutic options with GLP-1 RAs and considers the next generation of novel peptide co-agonists with the potential for improved therapeutic outcomes in obesity and type 2 diabetes.

Incretins: Beyond type 2 diabetes

While the use of incretins, including GLP-1 receptor agonists and PDD-IV inhibitors, is well established in the treatment of type 2 diabetes, many other aspects of these agents are yet to be discovered and utilized for their potential clinical benefit. These include the potential role of GLP-1 receptor agonists in the induction of weight loss, blood pressure reduction, anti-inflammatory and nephro- and cardio-protective actions. Their potential benefit in type 1 diabetes is also being investigated. This review will attempt to comprehensively describe novel discoveries in the field of incretin pathophysiology and pharmacology beyond their classical role in the treatment of type 2 diabetes.

A comparative safety review between GLP-1 receptor agonists and SGLT2 inhibitors for diabetes treatment

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium glucose cotransporter 2 inhibitors (SGLT2i) are of particular interest in type 2 diabetes treatment strategies, due to their efficacy in reducing HbA1c with a low risk of hypoglycaemia, to their positive effects on body weight and blood pressure and in light of their effects on cardiovascular risk and on nephroprotection emerged from the most recent cardiovascular outcome trials. Since it is therefore very likely that GLP-1RA and SGLT2i use will become more and more common, it is more and more important to gather and discuss information about their safety profile.

AREAS COVERED

Adverse events and the safety concerns most often emerged in trials with GLP-1RA namely, exenatide long acting release (LAR), dulaglutide, liraglutide, semaglutide, lixisenatide or SGLT2i, namely empagliflozin, dapagliflozin, canagliflozin and SGLT2i with an attempt at comparing the safety profiles of molecules of these two classes.

EXPERT OPINION

GLP-1RA and SGLT2i, although each associated with different specific side effects, share a 'similar' safety profile and are both drugs relatively easy to handle. The potentially complementary mechanisms of action, the cardio and nephroprotective effects demonstrated by molecules of both classes, make these drugs potentially useful even in add on to each other.

The GLP-1 response to glucose does not mediate beta and alpha cell dysfunction in Hispanics with abnormal glucose metabolism

AIMS

Glucagon-like peptide-1 (GLP-1) contributes to insulin secretion after meals. Though Hispanics have increased risk for type 2 diabetes mellitus, it is unknown if impaired GLP-1 secretion contributes to this risk. We therefore studied plasma GLP-1 secretion and action in Hispanic adults.

METHODS

Hispanic (H; n = 31) and non-Hispanic (nH; n = 15) participants underwent an oral glucose tolerance test (OGTT). All participants were categorized by glucose tolerance into four groups: normal glucose tolerant non-Hispanic (NGT-nH; n = 15), normal glucose tolerant Hispanic (NGT-H; n = 12), impaired glucose tolerant Hispanic (IGT-H; n = 11), or newly diagnosed type 2 diabetes mellitus, Hispanic (T2D-H; n = 8).

RESULTS

Glucose-induced increments in plasma GLP-1 (Δ-GLP-1) were not different in NGT-H and NGT-nH (p = .38), nor amongst Hispanic subgroups with varying degrees of glucose homeostasis (p = .6). In contrast, the insulinogenic index in T2D-H group was lower than the other groups (p = .016). Subjects with abnormal glucose homeostasis (AGH), i.e., T2D-H plus IGT-H, had a diminished glucagon suppression index compared to patients with normal glucose homeostasis (NGT-H plus NGT-nH) (p = .035).

CONCLUSIONS

GLP-1 responses to glucose were similar in Hispanic and Non-Hispanic NGT. Despite similar glucose-induced Δ-GLP-1, insulin and glucagon responses were abnormal in T2D-H and AGH, respectively. Thus, impaired GLP-1 secretion is unlikely to play a role in islet dysfunction in T2D. Although GLP-1 therapeutics enhance insulin secretion and glucagon suppression, it is likely due to pharmacological amplification of the GLP-1 pathways rather than treatment of hormonal deficiency.

Major adverse cardiovascular event reduction with GLP-1 and SGLT2 agents: evidence and clinical potential

Treatment of patients with type 2 diabetes is directed against treating symptoms of hyperglycemia, minimizing the risk of hypoglycemia, and the risk of microvascular and macrovascular complications. The majority of patients with type 2 diabetes die from cardiovascular or cerebrovascular disease. Future therapies should therefore focus on reducing cardiovascular morbidity in this high-risk population. Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2-i) are two drug classes with proven antihyperglycemic effect in type 2 diabetes. However, these drugs seem to have other effects such as weight reduction, low risk of hypoglycemia, and blood pressure reduction. Emerging evidence suggests pleiotropic effects, which potentially could be important in reducing cardiovascular risk. Prompted by regulatory authorities demanding cardiovascular outcome trials (CVOTs) assessing the cardiovascular safety of new antihyperglycemic drug candidates, many CVOTs are ongoing and a few of these are finalized. Somewhat surprising recent CVOTs in both drug classes have shown promising data on cardiovascular morbidity and mortality in patients with a very high risk of cardiovascular events. It is uncertain whether this is a class effect of the two drug classes, and it is yet unproven whether long-term cardiovascular benefits of these drugs can be extrapolated to populations at lower risk of cardiovascular disease. The aim of the present review is to give an overview of our current knowledge of the GLP-1RA and SGLT2-i classes, with specific focus on mechanisms of action, effects on cardiovascular risk factors and cardiovascular morbidity and mortality from the CVOTs presently available. The clinical potential of these data is discussed.

Glucagon-Like Peptide-1 Receptor Agonists for the Treatment of Type 2 Diabetes Mellitus: A Position Statement of the Korean Diabetes Association

The glucagon-like peptide-1 receptor agonists (GLP-1RAs) were recommended as a monotherapy or combination therapy with oral hypoglycemic agents or basal insulin in the position statement of the Korean Diabetes Association 2017 for pharmacological therapy. Many randomized clinical trials and systematic reviews report that GLP-1RAs have considerable glucose-lowering effect and lead to weight reduction and low risk of hypoglycemia when used as a monotherapy or combination therapy. The cardiovascular safety of GLP-1RAs has been assessed in several randomized clinical trials and systematic reviews. The results of cardiovascular outcome trials of long-acting GLP-1RAs (liraglutide, semaglutide) demonstrated cardiovascular benefits in subjects with type 2 diabetes mellitus and a high risk of cardiovascular disease. The GLP-1RA may be a choice of therapy when weight control and avoidance of hypoglycemia are important, and patients with high risk of cardiovascular disease might also favor choosing GLP-1RA.

Personalizing Type 2 Diabetes Management: Use of a Patient-Centered Approach to Individualizing A1C Goals and Pharmacological Regimens

IN BRIEF Caring for people with type 2 diabetes requires a patient-centered approach to treatment targets and medication regimens. Focusing on patients' individual characteristics, needs, and treatment responses can improve compliance and clinical outcomes. Medication selection can be guided by the mechanisms of action, advantages, disadvantages, and costs of available options; patients' behavioral and psychological variables, personal preferences, and socioeconomic status also should be taken into account. This article provides an overview of patient-centered and individualized diabetes management, offers pharmacological recommendations for specific clinical scenarios, and describes a complicated case illustrating the patient-centered approach in clinical practice.

Comparison between insulin degludec/liraglutide treatment and insulin glargine/lixisenatide treatment in type 2 diabetes: a systematic review and meta-analysis

AIM

To evaluate the efficacy and adverse effects of IDegLira and IGlarLixi treatment and to perform a comparison between two strategies.

METHODS

The registration number is CRD42017053952. Randomized controlled trials of IGlarLixi treatment or IDegLira treatment compared with placebo or active hypoglycemic agents in type 2 diabetes were included.

RESULTS

Eight trials were included. The absolute HbA1c change relative to baseline after IGlarLixi treatment was -1.50% with significance (95% CI, -1.89% to -1.12%, p < 0.01); the absolute HbA1c change after IDegLira treatment was -1.89% with significance (95% CI, -2.04% to -1.73%, p < 0.01). Comparisons between IGlarLixi treatment and IDegLira treatment indicated no significant differences between groups. The absolute weight change after IGlarLixi treatment significantly decreased (weighted mean difference (WMD), -0.62 kg; 95% CI, -0.93 to -0.31 kg, p = < 0.01), but the absolute weight change after IDegLira treatment was not significantly changed (WMD, -0.81 kg; 95% CI, -3.26 to 1.65 kg, p = 0.52). There were no significant differences between groups.

CONCLUSION

Glucose control of IGlarLixi treatment or IDegLira treatment was significantly lower than that at baseline. Comparisons between the two treatment groups indicated no significant differences between groups in absolute HbA1c changes or body weight changes relative to baseline.

Protective effects of the GLP-1 mimetic exendin-4 in Parkinson's disease

There is increasing interest in the potential role of glucagon-like peptide-1 (GLP-1) receptor agonists as neuroprotective treatments in neurodegenerative diseases including Parkinson's disease following the publication of the results of the Exenatide-PD trial. Of the current GLP-1 receptor agonists already licensed to treat Type 2 diabetes several including exenatide, liraglutide and lixisenatide are the subject of ongoing clinical trials in PD. The underlying rationale for using drugs licensed and effective for T2DM in PD patients therefore needs to be scrutinized, and the results obtained to date critically reviewed. We review the relationship between insulin resistance and Parkinson's disease, the implications on pathogenesis and the efforts to reposition GLP-1 agonists as potential treatments for Parkinson's disease and give an overview of the pre-clinical and clinical data supporting the use of exenatide in Parkinson's disease with a discussion regarding possible mechanisms of action. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'

A Hydrogel-Microsphere Drug Delivery System That Supports Once-Monthly Administration of a GLP-1 Receptor Agonist

We have developed a chemically controlled very long-acting delivery system to support once-monthly administration of a peptidic GLP-1R agonist. Initially, the prototypical GLP-1R agonist exenatide was covalently attached to hydrogel microspheres by a self-cleaving β-eliminative linker; after subcutaneous injection in rats, the peptide was slowly released into the systemic circulation. However, the short serum exenatide half-life suggested its degradation in the subcutaneous depot. We found that exenatide undergoes deamidation at Asn²⁸ with an in vitro and in vivo half-life of approximately 2 weeks. The [Gln²⁸]exenatide variant and exenatide showed indistinguishable GLP-1R agonist activities as well as pharmacokinetic and pharmacodynamic effects in rodents; however, unlike exenatide, [Gln²⁸]exenatide is stable for long periods. Two different hydrogel-[Gln²⁸]exenatide conjugates were prepared using β-eliminative linkers with different cleavage rates. After subcutaneous injection in rodents, the serum half-lives for the released [Gln²⁸]exenatide from the two conjugates were about 2 weeks and one month. Two monthly injections of the latter in the Zucker diabetic fatty rat showed pharmacodynamic effects indistinguishable from two months of continuously infused exenatide. Pharmacokinetic simulations indicate that the delivery system should serve well as a once-monthly GLP-1R agonist for treatment of type 2 diabetes in humans.

COMPARING CLINICAL OUTCOMES AND COSTS FOR DIFFERENT TREATMENT INTENSIFICATION APPROACHES IN PATIENTS WITH TYPE 2 DIABETES UNCONTROLLED ON BASAL INSULIN: ADDING GLUCAGON-LIKE PEPTIDE 1 RECEPTOR AGONISTS VERSUS ADDING RAPID-ACTING INSULIN OR INCREASING BASAL INSULIN DOSE

OBJECTIVE

Not all patients with type 2 diabetes achieve recommended glycated hemoglobin A_1c (A1C) levels after adequate titration of basal insulin (BI). Current intensification approaches include addition of rapid-acting insulin (RAI) or a glucagon-like peptide 1 receptor agonist (GLP-1 RA), but it is not clear which strategy results in better long-term outcomes.

METHODS

This retrospective analysis of health insurance claims data in the U.S. MarketScan database compared glycemic control and healthcare resource utilization and costs 12 months after adding a GLP-1 RA to BI versus adding a RAI or increasing BI doses. Propensity score matching was used in the comparative effectiveness analysis.

RESULTS

A total of 8,034 patients underwent treatment intensification within 6 months of showing poor glycemic control; 4,134 patients had their BI dose adjusted, and 2,076 and 331 received RAI and GLP-1 RA, respectively. A1C changes were similar for the GLP-1 RA and RAI cohorts but higher for the GLP-1 RA versus the dose-adjustment group. The hypoglycemia rate was lower after adding GLP-1 RA versus RAI or increasing BI dose. No overall changes in utilization of healthcare resources or diabetes-related costs were observed between intensification strategies, although prescription costs were higher for the GLP-1 RA cohort.

CONCLUSION

BI in combination with GLP-1 RAs appears to be an effective intensification strategy, further reducing A1C levels and hypoglycemia frequency compared to increasing BI doses. GLP-1 RA addition also decreases hypoglycemia frequency versus BI dose increases and RAI addition, without raising overall healthcare costs.

ABBREVIATIONS

A1C = hemoglobin A_1c; BI = basal insulin; CAD = coronary artery disease; ED = emergency department; FPG = fasting plasma glucose; GLP-1 RA = glucagon-like peptide 1 receptor agonist; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; NPH = neutral protamine Hagedorn; OAD = oral antidiabetes drug; PSM = propensity score matching; RAI = rapid-acting insulin; T2D = type 2 diabetes.

Effects of semaglutide on beta cell function and glycaemic control in participants with type 2 diabetes: a randomised, double-blind, placebo-controlled trial

AIMS/HYPOTHESIS

Semaglutide is a glucagon-like peptide-1 analogue in development for the treatment of type 2 diabetes. Its effects on first- and second-phase insulin secretion and other measures of beta cell function and glycaemic control were assessed.

METHODS

In this single-centre, double-blind, placebo-controlled, parallel-group trial, conducted at the Profil Institut für Stoffwechselforschung, Germany, 75 adult (aged 18-64 years) participants with type 2 diabetes (eligibility: HbA1c of 6.5-9.0% (47.5-74.9 mmol/mol); BMI 20.0-35.0 kg/m2; and treatment with diet and exercise and/or metformin monotherapy with a dose unchanged in the 30 days prior to screening) were randomised (1:1) to once-weekly s.c. semaglutide 1.0 mg (0.25, 0.5, 1.0 mg escalated) or placebo for 12 weeks. Co-primary endpoints were changes from baseline to end of treatment in the first (AUC0-10 min) and second (AUC10-120 min) insulin secretion phases, as measured by the IVGTT. An arginine stimulation test (AST) and a 24 h meal stimulation test were also conducted. A graded glucose infusion test (GGIT) assessed insulin secretion rate (ISR) in treated participants and a group of untreated healthy participants. Safety endpoints were also assessed.

RESULTS

In total, 37 participants received semaglutide and 38 received placebo. Following IVGTT, for insulin, both AUC0-10min and AUC10-120min were significantly increased with semaglutide (estimated treatment ratio [95% CI] 3.02 [2.53, 3.60] and 2.10 [1.86, 2.37], respectively; p < 0.0001). The 24 h meal test showed reduced fasting, postprandial and overall (AUC0-24h) glucose and glucagon responses with semaglutide (p < 0.0001). The AST showed that maximal insulin capacity increased following semaglutide treatment. During GGIT, semaglutide significantly increased ISR to levels similar to those in healthy participants. Semaglutide was well tolerated.

CONCLUSIONS/INTERPRETATION

Twelve weeks of once-weekly treatment with semaglutide significantly improved beta cell function and glycaemic control in participants with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02212067 FUNDING: The study was funded by Novo Nordisk A/S.

The safety of albiglutide for the treatment of type 2 diabetes

INTRODUCTION

Albiglutide is a marketed long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection. It has significantly less gastrointestinal side effects than other GLP-1 RAs in current use but does not improve HbA1c or promote weight loss to the same extent as competitor agents such as liraglutide. Area Covered: The safety of albiglutide is discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents. Expert Opinion: Unlike competitor agents, the gastrointestinal side effects of albiglutide are not much greater than placebo. It has been studied and appears safe at all stages of renal failure. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long term study now underway will determine if albiglutide, with its relatively favorable GI tolerance, has a place in the treatment of patients with increased risk of cardiovascular events.

Glucose kinetics: an update and novel insights into its regulation by glucagon and GLP-1

PURPOSE OF REVIEW

Glucagon and GLP-1 share the same origin (i.e., proglucagon); primarily GLP-1 is generated from intestinal L-cells and glucagon from pancreatic α-cell, but intestinal glucagon and pancreatic GLP-1 secretion is likely. Glucose kinetics are tightly regulated by pancreatic hormones insulin and glucagon, but other hormones, including glucagon-like peptide-1 (GLP-1), also play an important role. The purpose of this review is to describe the recent findings on the mechanisms by which these two hormones regulate glucose kinetics.

RECENT FINDINGS

Recent findings showed new important mechanisms of action of glucagon and GLP-1 in the regulation of glucose metabolism. Knock out of glucagon receptors protects against hyperglycemia without causing hypoglycemia. GLP-1 not only stimulates insulin secretion, but it has also an independent effect on the liver and inhibits glucose production. Moreover, when coinfused with glucagon, GLP-1 limits the hyperglycemic effects. Both hormones have also central effects on gastric emptying (delayed), intestinal motility (reduced), and satiety (increased).

SUMMARY

The implications of these findings are very important for the management of type 2 diabetes given that GLP-1 receptor agonist are currently approved for the treatment of hyperglycemia and glucagon receptor antagonists and GLP-1/glucagon dual agonists are under development.

No cognitive-enhancing effect of GLP-1 receptor agonism in antipsychotic-treated, obese patients with schizophrenia

OBJECTIVE

Schizophrenia is associated with profound cognitive and psychosocial impairments. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used for diabetes and obesity treatment, and animal studies have indicated cognitive-enhancing effects. In this investigator-initiated, double-blind, randomized, placebo-controlled trial, we tested non-metabolic effects of exenatide once-weekly (Bydureon™) in obese, antipsychotic-treated patients with schizohrenia spectrum disorder.

METHOD

Before and after 3 months of exenatide (N = 20) or placebo (N = 20) treatment, patients were assessed with the following: Brief Assessment of Cognition in Schizophrenia (BACS), Rey-Osterreith complex figure test (REY), Short-Form Health Survey (SF-36), Personal and Social Performance Scale (PSP) and the Positive and Negative Syndrome Scale (PANSS). We used BACS composite score as the main outcome measure.

RESULTS

Repeated measures analysis of variance on BACS composite score showed significant effect of 'Time' (P < 0.001), no effect of 'Group' (P = 0.64) and no 'Time*Group' interaction (P = 0.77). For REY, SF-36, PSP and PANSS, only significant 'Time' effects were found.

CONCLUSION

The non-significant results of this first clinical trial exploring non-metabolic effects of a long-acting GLP-1RA in patients with schizophrenia could reflect a general problem of translating cognitive-enhancing effects of GLP-1RAs from animals to humans or be explained by factors specifically related to schizophrenia spectrum patients with obesity such as antipsychotic treatment.

Effect of Liraglutide Treatment on Prediabetes and Overweight or Obesity in Clozapine- or Olanzapine-Treated Patients With Schizophrenia Spectrum Disorder: A Randomized Clinical Trial

Importance

Compared with the general population, patients with schizophrenia have a 2- to 3-fold higher mortality rate primarily caused by cardiovascular disease. Previous interventions designed to counteract antipsychotic-induced weight gain and cardiometabolic disturbances reported limited effects.

Objectives

To determine the effects of the glucagon-like peptide-1 receptor agonist liraglutide added to clozapine or olanzapine treatment of schizophrenia spectrum disorders.

Design, Setting, and Participants

This randomized clinical double-blind trial enrolled participants at 2 clinical sites in Denmark. Of 214 eligible participants with a schizophrenia spectrum disorder, 103 were randomized to liraglutide or placebo. Participants received stable treatment with clozapine or olanzapine, were overweight or obese, and had prediabetes. Data were collected from May 1, 2013, through February 25, 2016.

Interventions

Treatment for 16 weeks with once-daily subcutaneous injection of liraglutide or placebo. Trial drug therapy was titrated during the first 2 weeks of the study.

Main Outcomes and Measures

The primary end point was change in glucose tolerance estimated by a 75-g oral glucose tolerance test result. Secondary end points included change in body weight and cardiometabolic parameters.

Results

Of the 103 patients undergoing randomization (60 men [58.3%] and 43 women [41.7%]), 97 were included in the efficacy analysis, with a mean (SD) age of 42.5 (10.5) years and mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 33.8 (5.9). The liraglutide and placebo groups had comparable characteristics (mean [SD] age, 42.1 [10.7] vs 43.0 [10.5] years; 30 men in each group; mean [SD] body mass index, 33.7 [5.1] vs 33.9 [6.6]). A total of 96 randomized participants (93.2%) completed the trial. Glucose tolerance improved in the liraglutide group compared with the placebo group (P < .001). Altogether, 30 liraglutide-treated participants (63.8%) developed normal glucose tolerance compared with 8 placebo-treated participants (16.0%) (P < .001; number needed to treat, 2). Body weight decreased with liraglutide compared with placebo (-5.3 kg; 95% CI, -7.0 to -3.7 kg). Reductions in waist circumference (-4.1 cm; 95% CI, -6.0 to -2.3 cm), systolic blood pressure (-4.9 mm Hg; 95% CI, -9.5 to -0.3 mm Hg), visceral fat (-250.19 g; 95% CI, -459.9 to -40.5 g), and low-density lipoprotein levels (-15.4 mg/dL; 95% CI, -23.2 to -7.7 mg/dL) occurred with liraglutide compared with placebo. Adverse events with liraglutide affected mainly the gastrointestinal tract.

Conclusions and Relevance

Liraglutide significantly improved glucose tolerance, body weight, and cardiometabolic disturbances in patients with schizophrenia spectrum disorders treated with clozapine or olanzapine.

Trial Registration

clinicaltrials.gov Identifier: NCT01845259.

Pharmacologic Management of Type 2 Diabetes Mellitus: Available Therapies

Choices for the treatment of type 2 diabetes mellitus (T2DM) have multiplied as our understanding of the underlying pathophysiologic defects has evolved. Treatment should target multiple defects in T2DM and follow a patient-centered approach that considers factors beyond glycemic control, including cardiovascular risk reduction. The American Association of Clinical Endocrinologists/American College of Endocrinology and the American Diabetes Association recommend an initial approach consisting of lifestyle changes and monotherapy, preferably with metformin. Therapy choices are guided by glycemic efficacy, safety profiles, particularly effects on weight and hypoglycemia risk, tolerability, patient comorbidities, route of administration, patient preference, and cost. Balancing management of hyperglycemia with the risk of hypoglycemia and consideration of the effects of pharmacotherapy on weight figure prominently in US-based T2DM recommendations, whereas less emphasis has been placed on the ability of specific medications to affect cardiovascular outcomes. This is likely because, until recently, specific glucose-lowering agents have not been shown to affect cardiorenal outcomes. The Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME), the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial, and the Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes 6 (SUSTAIN-6) recently showed a reduction in overall cardiovascular risk with empagliflozin, liraglutide, and semaglutide treatment, respectively. Moreover, empagliflozin has become the first glucose-lowering agent indicated to reduce the risk of cardiovascular death in adults with T2DM and established cardiovascular disease. Results from cardiovascular outcomes trials have prompted an update to the 2017 American Diabetes Association standards of care, which now recommend consideration of empagliflozin or liraglutide for patients with suboptimally controlled long-standing T2DM and established atherosclerotic cardiovascular disease because these agents have been shown to reduce cardiovascular and all-cause mortality when added to standard care.

Short-acting glucagon-like peptide-1 receptor agonists as add-on to insulin therapy in type 1 diabetes: A review

A large proportion of patients with type 1 diabetes do not reach their glycaemic target of glycated hemoglobin (HbA1c) <7.0% (53 mmol/mol) and, furthermore, an increasing number of patients with type 1 diabetes are overweight and obese. Treatment of type 1 diabetes is based on insulin therapy, which is associated with well-described and unfortunate adverse effects such as hypoglycaemia and increased body weight. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are the focus of increasing interest as a possible adjunctive treatment to insulin in type 1 diabetes because of their glucagonostatic and extrapancreatic effects. So far, the focus has mainly been on the long-acting GLP-1RAs, but the risk-benefit ratio emerging from studies evaluating the effect of long-acting GLP-1RAs as adjunctive therapy to insulin therapy in patients with type 1 diabetes has been disappointing. This might be attributable to a lack of glucagonostatic effect of these long-acting GLP-1RAs in type 1 diabetes, alongside development of tachyphylaxis to GLP-1-induced retardation of gastric emptying. In contrast, the short-acting GLP-1RAs seem to have a preserved and sustained effect on glucagon secretion and gastric emptying in patients with type 1 diabetes, which could translate into effective lowering of postprandial glucose excursions; however, these observations regarding short-acting GLP-1RAs are all derived from small open-label trials and should thus be interpreted with caution. In the present paper we review the potential role of GLP-1RAs, in particular short-acting GLP-1RAs, as add-on to insulin in the treatment of type 1 diabetes.

Pharmacologic Management of Type 2 Diabetes Mellitus: Available Therapies

Choices for the treatment of type 2 diabetes mellitus (T2DM) have multiplied as our understanding of the underlying pathophysiologic defects has evolved. Treatment should target multiple defects in T2DM and follow a patient-centered approach that considers factors beyond glycemic control, including cardiovascular risk reduction. The American Association of Clinical Endocrinologists/American College of Endocrinology and the American Diabetes Association recommend an initial approach consisting of lifestyle changes and monotherapy, preferably with metformin. Therapy choices are guided by glycemic efficacy, safety profiles, particularly effects on weight and hypoglycemia risk, tolerability, patient comorbidities, route of administration, patient preference, and cost. Balancing management of hyperglycemia with the risk of hypoglycemia and consideration of the effects of pharmacotherapy on weight figure prominently in US-based T2DM recommendations, whereas less emphasis has been placed on the ability of specific medications to affect cardiovascular outcomes. This is likely because, until recently, specific glucose-lowering agents have not been shown to affect cardiorenal outcomes. The Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME), the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial, and the Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes 6 (SUSTAIN-6) recently showed a reduction in overall cardiovascular risk with empagliflozin, liraglutide, and semaglutide treatment, respectively. Moreover, empagliflozin has become the first glucose-lowering agent indicated to reduce the risk of cardiovascular death in adults with T2DM and established cardiovascular disease. Results from cardiovascular outcomes trials have prompted an update to the 2017 American Diabetes Association standards of care, which now recommend consideration of empagliflozin or liraglutide for patients with suboptimally controlled long-standing T2DM and established atherosclerotic cardiovascular disease because these agents have been shown to reduce cardiovascular and all-cause mortality when added to standard care.

Efficacy and safety of once-weekly semaglutide versus once-daily insulin glargine as add-on to metformin (with or without sulfonylureas) in insulin-naive patients with type 2 diabetes (SUSTAIN 4): a randomised, open-label, parallel-group, multicentre, multinational, phase 3a trial

BACKGROUND

Several pharmacological treatment options are available for type 2 diabetes; however, many patients do not achieve optimum glycaemic control and therefore new therapies are necessary. We assessed the efficacy and safety of semaglutide, a glucagon-like peptide-1 (GLP-1) analogue in clinical development, compared with insulin glargine in patients with type 2 diabetes who were inadequately controlled with metformin (with or without sulfonylureas).

METHODS

We did a randomised, open-label, non-inferiority, parallel-group, multicentre, multinational, phase 3a trial (SUSTAIN 4) at 196 sites in 14 countries. Eligible participants were insulin-naive patients with type 2 diabetes, aged 18 years and older, who had insufficient glycaemic control with metformin either alone or in combination with a sulfonylurea. We randomly assigned participants (1:1:1) to either subcutaneous once-weekly 0·5 mg or 1·0 mg semaglutide (doses reached after following a fixed dose-escalation regimen) or once-daily insulin glargine (starting dose 10 IU per day, then titrated weekly to a pre-breakfast self-measured plasma glucose target of 4·0-5·5 mmol/L [72-99 mg/dL]) for 30 weeks. In all treatment groups, previous background metformin and sulfonylurea treatment was continued throughout the trial. We did the randomisation using an interactive voice or web response system. The primary endpoint was change in mean HbA_1c from baseline to week 30 and the confirmatory secondary endpoint was the change in mean bodyweight from baseline to week 30. We assessed efficacy and safety in the modified intention-to-treat population (mITT; all randomly assigned participants who were exposed to at least one dose of study drug) and used a margin of 0·3% to establish non-inferiority in HbA_1c reduction. This trial is registered with ClinicalTrials.gov, number NCT02128932.

FINDINGS

Between Aug 4, 2014, and Sept 3, 2015, we randomly assigned 1089 participants to treatment; the mITT population consisted of 362 participants assigned to 0·5 mg semaglutide, 360 to 1·0 mg semaglutide, and 360 to insulin glargine. 49 (14%) participants assigned to 0·5 mg semaglutide discontinued treatment prematurely, compared with 55 (15%) assigned to 1·0 mg semaglutide, and 26 (7%) assigned to insulin glargine. Most discontinuations were due to adverse events-mostly gastrointestinal with semaglutide, and others such as skin and subcutaneous tissue disorders (eg, rash, pruritus, and urticaria) with insulin glargine. From a mean baseline HbA_1c of 8·17% (SD 0·89), at week 30, 0·5 and 1·0 mg semaglutide achieved reductions of 1·21% (95% CI 1·10-1·31) and 1·64% (1·54-1·74), respectively, versus 0·83% (0·73-0·93) with insulin glargine; estimated treatment difference versus insulin glargine -0·38% (95% CI -0·52 to -0·24) with 0·5 mg semaglutide and -0·81% (-0·96 to -0·67) with 1·0 mg semaglutide (both p<0·0001). Mean bodyweight at baseline was 93·45 kg (SD 21·79); at week 30, 0·5 and 1·0 mg semaglutide achieved weight losses of 3·47 kg (95% CI 3·00-3·93) and 5·17 kg (4·71-5·66), respectively, versus a weight gain of 1·15 kg (0·70-1·61) with insulin glargine; estimated treatment difference versus insulin glargine -4·62 kg (95% CI -5·27 to -3·96) with 0·5 mg semaglutide and -6·33 kg (-6·99 to -5·67) with 1·0 mg semaglutide (both p<0·0001). Severe or blood glucose-confirmed hypoglycaemia was reported by 16 (4%) participants with 0·5 mg semaglutide and 20 (6%) with 1·0 mg semaglutide versus 38 (11%) with insulin glargine (p=0·0021 and p=0·0202 for 0·5 mg and 1·0 mg semaglutide vs insulin glargine, respectively). Severe hypoglycaemia was reported by two (<1%) participants with 0·5 mg semaglutide, five (1%) with 1·0 mg semaglutide, and five (1%) with insulin glargine. Six deaths were reported: four (1%) in the 0·5 mg semaglutide group (three cardiovascular deaths, one pancreatic carcinoma, which was assessed as being possibly related to study medication) and two (<1%) in the insulin glargine group (both cardiovascular death). The most frequently reported adverse events were nausea with semaglutide, reported in 77 (21%) patients with 0·5 mg and in 80 (22%) with 1·0 mg, and nasopharyngitis reported in 44 (12%) patients with insulin glargine.

INTERPRETATION

Compared with insulin glargine, semaglutide resulted in greater reductions in HbA_1c and weight, with fewer hypoglycaemic episodes, and was well tolerated, with a safety profile similar to that of other GLP-1 receptor agonists.

FUNDING

Novo Nordisk A/S.

Efficacy and safety of once-weekly semaglutide versus once-daily sitagliptin as an add-on to metformin, thiazolidinediones, or both, in patients with type 2 diabetes (SUSTAIN 2): a 56-week, double-blind, phase 3a, randomised trial

BACKGROUND

Semaglutide is a novel glucagon-like peptide-1 (GLP-1) analogue, suitable for once-weekly subcutaneous administration, in development for treatment of type 2 diabetes. We assessed the efficacy and safety of semaglutide versus the dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin in patients with type 2 diabetes inadequately controlled on metformin, thiazolidinediones, or both.

METHODS

We did a 56-week, phase 3a, randomised, double-blind, double-dummy, active-controlled, parallel-group, multinational, multicentre trial (SUSTAIN 2) at 128 sites in 18 countries. Eligible patients were aged at least 18 years (or at least 20 years in Japan) and diagnosed with type 2 diabetes, with insufficient glycaemic control (HbA_1c 7·0-10·5% [53·0-91·0 mmol/mol]) despite stable treatment with metformin, thiazolidinediones, or both. We randomly assigned participants (2:2:1:1) using an interactive voice or web response system to 56 weeks of treatment with subcutaneous semaglutide 0·5 mg once weekly plus oral sitagliptin placebo once daily, subcutaneous semaglutide 1·0 mg once weekly plus oral sitagliptin placebo once daily, oral sitagliptin 100 mg once daily plus subcutaneous semaglutide placebo 0·5 mg once weekly, or oral sitagliptin 100 mg once daily plus subcutaneous semaglutide placebo 1·0 mg once weekly. The two oral sitagliptin 100 mg groups (with semaglutide placebo 0·5 mg and 1·0 mg) were pooled for the analyses. The primary endpoint was change in HbA_1c from baseline to week 56, assessed in the modified intention-to-treat population (all randomly assigned participants who received at least one dose of study drug); change in bodyweight from baseline to week 56 was the confirmatory secondary endpoint. Safety endpoints included adverse events and hypoglycaemic episodes. This trial is registered with ClinicalTrials.gov, number NCT01930188.

FINDINGS

Between Dec 2, 2013, and Aug 5, 2015, we randomly assigned 1231 participants; of the 1225 included in the modified intention-to-treat analysis, 409 received semaglutide 0·5 mg, 409 received semaglutide 1·0 mg, and 407 received sitagliptin 100 mg. Mean baseline HbA_1c was 8·1% (SD 0·93); at week 56, HbA_1c was reduced by 1·3% in the semaglutide 0·5 mg group, 1·6% in the semaglutide 1·0 mg group, and 0·5% with sitagliptin (estimated treatment difference vs sitagliptin -0·77% [95% CI -0·92 to -0·62] with semaglutide 0·5 mg and -1·06% [-1·21 to -0·91] with semaglutide 1·0 mg; p<0·0001 for non-inferiority and for superiority, for both semaglutide doses vs sitagliptin). Mean baseline bodyweight was 89·5 kg (SD 20·3); at week 56, bodyweight reduced by 4·3 kg with semaglutide 0·5 mg, 6·1 kg with semaglutide 1·0 mg, and 1·9 kg with sitagliptin (estimated treatment difference vs sitagliptin -2·35 kg [95% CI -3·06 to -1·63] with semaglutide 0·5 mg and -4·20 kg [-4·91 to -3·49] with semaglutide 1·0 mg; p<0·0001 for superiority, for both semaglutide doses vs sitagliptin). The proportion of patients who discontinued treatment because of adverse events was 33 (8%) for semaglutide 0·5 mg, 39 (10%) for semaglutide 1·0 mg, and 12 (3%) for sitagliptin. The most frequently reported adverse events in both semaglutide groups were gastrointestinal in nature: nausea was reported in 73 (18%) who received semaglutide 0·5 mg, 72 (18%) who received semaglutide 1·0 mg, and 30 (7%) who received placebo, and diarrhoea was reported in 54 (13%) who received semaglutide 0·5 mg, 53 (13%) who received semaglutide 1·0 mg, and 29 (7%) who received placebo. Seven (2%) patients in the semaglutide 0·5 mg group, two (<1%) in the semaglutide 1·0 mg group, and five (1%) in the sitagliptin group had blood-glucose confirmed hypoglycaemia. There were six fatal events (two in the semaglutide 0·5 mg group, one in the semaglutide 1·0 mg group, and three in the sitagliptin group); none were considered likely to be related to the trial drugs.

INTERPRETATION

Once-weekly semaglutide was superior to sitagliptin at improving glycaemic control and reducing bodyweight in participants with type 2 diabetes on metformin, thiazolidinediones, or both, and had a similar safety profile to that of other GLP-1 receptor agonists. Semaglutide seems to be an effective add-on treatment option for this patient population.

FUNDING

Novo Nordisk A/S.

Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options

The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.

Glucagon-like Peptide-1 Receptor Agonist Treatment Attributes Important to Injection-Naïve Patients with Type 2 Diabetes Mellitus: A Multinational Preference Study

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) differ in efficacy, side effects, dosing frequency, and device-related attributes. This study assessed the relative importance of treatment-related attributes in influencing preferences for GLP-1RAs among injection-naïve patients with type 2 diabetes mellitus (T2DM).

METHODS

Injection-naïve T2DM patients from five countries completed a Web-based discrete choice experiment (DCE) survey. Patients chose between hypothetical treatment profiles reflecting important and differentiating attributes of GLP-1RAs. Eight attributes were included: efficacy, side effects, device size, needle size, titration, preparation, evidence of long-term efficacy/safety, and dosing frequency. Odds ratios (ORs) and 95% confidence intervals were calculated using a conditional logit model to indicate the likelihood of choosing a treatment with a given attribute level versus a reference attribute level. The influence of individual attributes when considering full treatment profiles was examined using exenatide once weekly (QW) and liraglutide once daily (QD) as case examples.

RESULTS

A total of 1482 patients with T2DM completed the DCE survey. Side effects, efficacy, and dosing frequency were the three most important attributes influencing preferences; needle size, device size, and required preparation were least important. Total sample analysis indicated that a profile of GLP-1RA approximating exenatide QW (single pen) was preferred over a profile approximating liraglutide QD (OR 3.36; p < 0.001), when efficacy was assumed to be equal.

CONCLUSION

The most influential drivers of treatment preferences for a hypothetical GLP-RA profile were side effects, efficacy, and dosing frequency among injection-naïve T2DM patients. Preference elicitation can promote patient-centered care and inform new generations of T2DM treatments, which can lead to improved adherence and health outcomes.

Glucagon-Like Peptide-1 Receptor Agonist Treatment Attributes Important to Injection-Experienced Patients with Type 2 Diabetes Mellitus: A Preference Study in Germany and the United Kingdom

INTRODUCTION

This study assessed the relative importance of treatment-related attributes in influencing patient preferences for glucagon-like peptide-1 receptor agonists (GLP-1RAs) among injection-experienced type 2 diabetes mellitus (T2DM) patients in Germany and the United Kingdom.

METHODS

T2DM patients experienced with injecting once-weekly (QW) exenatide or once-daily (QD) liraglutide completed an online discrete-choice experiment (DCE) survey. Patients chose between hypothetical blinded treatment profiles reflecting attributes of GLP-1RAs. The DCE survey included eight attributes: efficacy, side effects, device size, needle size, titration, injection preparation, long-term efficacy/safety, and dosing frequency. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a conditional logit model indicating the likelihood of choosing a treatment with a given attribute level versus a reference attribute level.

RESULTS

510 GLP-1RA injection-experienced patients completed the survey; 45.3% respondents were being treated with exenatide QW and 54.7% respondents were being treated with liraglutide QD. In terms of GLP-1RA attributes, patients indicated a preference for a treatment with greater efficacy (i.e., a 1.5-point improvement in HbA1c) (OR 2.58; 95% CI 2.37, 2.80; p < 0.001), fewer side effects (OR 2.67; 95% CI 2.52, 2.82; p < 0.001), once-weekly rather than once-daily administration (OR 2.26; 95% CI 2.13, 2.39; p < 0.001), and the preparation required for a multi-use pen (OR 1.71; 95% CI 1.55, 1.88; p < 0.001). Needle size, device size, and titration were not significant drivers of patient preference.

CONCLUSIONS

Among GLP-1RA injection-experienced patients, key drivers of treatment preference for a hypothetical GLP-RA profile were side effects, efficacy, dosing frequency, and required preparation. Understanding patient preferences is important for optimizing treatment decision-making and improving treatment adherence.

FUNDING

AstraZeneca.

Oxyntomodulin analog and exendin-4 derivative lower plasma glucose in cattle

The present study was undertaken with the aim of examining whether and how exendin-4 (1-3) fragment, ie, Ex-4 (1-3) fragment, contributes to the regulation of glucose. An analog of oxyntomodulin (OXM) ([Gly², Glu³]-OXM), a glucagon analog ([Gly², Glu³]-glucagon), and two derivatives of Ex-4 (glucandin and [Gly², Glu³]-glucandin) were synthesized by substituting with Gly², Glu³ at the N-terminuses of OXM and glucagon and/or by attaching Ex-4 (30-39) amide at the C-terminus of glucagon. Effects of these peptides on plasma insulin and glucose concentrations were investigated in cattle by conducting 3 in vivo experiments. In all 3 experiments, 0.1% BSA saline was injected as a control. In experiment 1, glucandin (amino acid sequence was glucagon [1-29]-Ex-4 [30-39] amide) and [Gly², Glu³]-glucandin were injected at the dose rates of 5 μg/kg BW in 4-mo-old Holstein steers. Results showed that glucoregulatory effects of glucandin were similar to those of glucagon. [Gly², Glu³]-glucandin stimulated insulin secretion at 2 to 10 min and lowered glucose concentrations at 15 to 75 min. Experiment 2 was carried out to better understand the glucose-lowering potency of [Gly², Glu³]-glucandin, in comparison with Ex-4 and glucagon-like peptide-1 (GLP-1), using 4.5-mo-old Holstein steers. [Gly², Glu³]-glucandin was injected at dose rates of 0.3 μg/kg BW, 1.0 μg/kg BW, 3.2 μg/kg BW, and 6.4 μg/kg BW. Ex-4 and GLP-1 were injected at dose rates of 0.3 μg/kg BW. Results showed that the insulinotropic and glucose-lowering effects of [Gly², Glu³]-glucandin were not as potent as for Ex-4 and GLP-1, and the minimum effective dose of [Gly², Glu³]-glucandin to regulate plasma glucose concentrations was 3.2 μg/kg BW. In experiment 3, [Gly², Glu³]-OXM and [Gly², Glu³]-glucagon were injected at dose rates of 5 μg/kg BW in 5-mo-old Holstein steers. Both [Gly², Glu³]-OXM and [Gly², Glu³]-glucagon increased insulin concentration. [Gly², Glu³]-OXM potently lowered plasma glucose, but [Gly², Glu³]-glucagon did not change it. In summary, our findings clearly demonstrate that Ex-4 (1-3) fragment contributes to the regulation of glucose. [Gly², Glu³]-OXM and [Gly², Glu³]-glucandin are insulinotropic and glucose-lowering peptides. It was of interest that the substitution of the first 3 amino acids of OXM with Ex-4 (1-3) could reverse the upregulation of glucose by OXM into downregulation of glucose. In lowering glycemia, [Gly², Glu³]-OXM seemed almost as effective as Ex-4, and [Gly², Glu³]-glucandin was less profound than Ex-4. These findings contributed new insights into the hormonal regulation of glucose in ruminants. The action of [Gly², Glu³]-OXM and [Gly², Glu³]-glucandin might provide an advantage in glycemic control of insulin resistance in cattle and humans.

Novel strategies in the oral delivery of antidiabetic peptide drugs - Insulin, GLP 1 and its analogs

As diabetes is a complex disorder being a major cause of mortality and morbidity in epidemic rates, continuous research has been done on new drug types and administration routes. Up to now, a large number of therapeutic peptides have been produced to treat diabetes including insulin, glucagon-like peptide-1 (GLP-1) and its analogs. The most common route of administration of these antidiabetic peptides is parenteral. Due to several drawbacks associated with this invasive route, delivery of these antidiabetic peptides by the oral route has been a goal of pharmaceutical technology for many decades. Dosage form development should focus on overcoming the limitations facing oral peptides delivery as degradation by proteolytic enzymes and poor absorption in the gastrointestinal tract (GIT). This review focuses on currently developed strategies to improve oral bioavailability of these peptide based drugs; evaluating their advantages and limitations in addition to discussing future perspectives on oral peptides delivery. Depending on the previous reports and papers, the area of nanocarriers systems including polymeric nanoparticles, solid lipid nanoparticles, liposomes and micelles seem to be the most promising strategy that could be applied for successful oral peptides delivery; but still further potential attempts are required to be able to achieve the FDA approved oral antidiabetic peptide delivery system.