Glucagon-like peptide-1 receptor agonists in type 2 diabetes treatment: are they all the same?

Efficacy and safety of polyethylene glycol loxenatide monotherapy in type 2 diabetes patients: A multicentre, randomized, double-blind, placebo-controlled phase 3a clinical trial

AIM

To evaluate the efficacy and safety of polyethylene glycol loxenatide (PEX168) monotherapy in type 2 diabetes (T2D) patients in China.

MATERIALS AND METHODS

In a multicentred, randomized, double-blinded, placebo-controlled phase 3a clinical trial, 361 patients with inadequate glycaemic control (HbA1c 7.0%-10.5%, fasting plasma glucose <13.9 mmol/L) were randomized (1:1:1) for weekly subcutaneous injections: placebo, PEX168/100 μg or PEX168/200 μg. The 24-week treatment was followed by a 28-week extension, during which placebo-treated patients were randomly assigned to PEX168/100 μg or PEX168/200 μg. The primary efficacy endpoint was the HbA1c change from baseline to week 24.

RESULTS

The three groups had similar demographics and baseline characteristics. The HbA1c least-square mean (95% CI) change from baseline to week 24 was greater for PEX168/100 μg (-1.02% [-1.21%, -0.83%]) and PEX168/200 μg (-1.34% [-1.54%, -1.15%]) than for placebo (-0.17% [-0.36%, 0.02%]); (superiority: P < .0001). The proportions of patients with less than 7% HbA1c in the placebo, PEX168/100 μg and PEX168/200 μg groups were 15.7%, 34.7% and 46.6%, respectively. Common gastrointestinal adverse events (AEs) were nausea (5.6%, 10.0% and 0% for PEX168/100 μg, PEX168/200 μg and placebo, respectively) and vomiting (2.4%, 8.3% and 0% for PEX168/100 μg, PEX168/200 μg and placebo, respectively). Six (1.6%) patients (PEX168/100 μg: N = 2 [1.6%], PEX168/200 μg: N = 3 [2.5%] and placebo: N = 1 [0.8%]) discontinued treatment because of AEs. Four (1.2%) patients (PEX168/100 μg: N = 3 [2.5%] and PEX168/200 μg: N = 1 [0.9%]) developed PEX168 antidrug antibodies.

CONCLUSION

PEX168 monotherapy significantly improved glycaemic control in T2D patients with a safety profile resembling that of other glucagon-like peptide-1 receptor agonists.

Patient initiation and maintenance of GLP-1 RAs for treatment of obesity: a narrative review and practical considerations for primary care providers

Obesity is a chronic, relapsing metabolic disease, linked to a number of health risks and serious complications. Although highly prevalent in adults in the United States, it is underdiagnosed and untreated. Primary care providers (PCPs) are uniquely poised to diagnose and treat patients with obesity, using a selection of treatment strategies including lifestyle modifications and pharmacotherapies. As a physiological regulator of appetite and energy intake, the glucagon-like peptide-1 receptor agonist (GLP-1 RA) liraglutide 3.0 mg is approved for chronic weight management in individuals with overweight (pre-obesity) or obesity. In this review, we provide an overview of the clinical data supporting the use of liraglutide 3.0 mg, as well as practical advice for PCPs on the initiation and maintenance of treatment over the long term. This also covers the management of side effects and how to manage patient expectations over time.

The new type 2 diabetes mellitus therapy: comparison between the two classes of drugs GLPR (glucagon-like peptide receptor) agonists and SGLT2 (sodium-glucose cotransporter 2) inhibitors

Type 2 diabetes mellitus represents one of the most common chronic-degenerative diseases in modern society and is the cause of innumerable micro- and macrovascular complications that weigh on the national health system. Until a few years ago, there was no anti-diabetic drug that, in addition to lowering blood sugar, had an impact on cardiovascular risk in these patients. In this report, we will analyse the characteristics, contraindications, and evidence in favour of the use of two innovative categories of molecules that aim, for the first time in history, at controlling blood sugar levels and simultaneously lower cardiovascular risk in diabetics individuals: the glucagon-like peptide receptor agonists and the sodium–glucose cotransporter 2 inhibitors.

Where Does Metformin Stand in Modern Day Management of Type 2 Diabetes?

Metformin is the most commonly used glucose-lowering therapy (GLT) worldwide and remains the first-line therapy for newly diagnosed individuals with type 2 diabetes (T2D) in management algorithms and guidelines after the UK Prospective Diabetes Study (UKPDS) showed cardiovascular mortality benefits in the overweight population using metformin. However, the improved Major Adverse Cardiovascular Events (MACE) realised in some of the recent large cardiovascular outcomes trials (CVOTs) using sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have challenged metformin's position as a first-line agent in the management of T2D. Many experts now advocate revising the existing treatment algorithms to target atherosclerotic cardiovascular disease (ASCVD) and improving glycaemic control as a secondary aim. In this review article, we will revisit the major cardiovascular outcome data for metformin and include a critique of the UKPDS data. We then review additional factors that might be pertinent to metformin's status as a first-line agent and finally answer key questions when considering metformin's role in the modern-day management of T2D.

ZG02 Improved Hepatic Glucose Metabolism and Insulin Sensitivity via Activation of AMPK/Sirt1 Signaling Pathways in a High-fat Diet/Streptozotocin-induced Type 2 Diabetes Model

PURPOSE

The aim of the present study was to investigate the hypoglycemic activity and potential mechanism of tetrahydrocarbazole derivatives ZG02 in high-fat diet/streptozotocin-induced type 2 diabetes model.

METHODS

C57BL/6 mice (n=30) were randomly assigned to three groups: control group (n=10) was fed with normal diet, the diabetes group (n=10) was fed with high-fat diet for eight weeks followed by intraperitoneal injection of streptozotocin (25 mg/kg) and the ZG02 group (n=10) injected intraperitoneally with ZG02 (30 mg/kg/day) for two weeks after successful modeling. The changes of weight, fasting blood glucose, oral glucose tolerance and fasting blood insulin levels in each group were evaluated. In addition, we also assessed the expression level of total AMPK, phosphorylation AMPK, SIRT1, PGC-1 and the activity of G6PC in liver.

RESULTS

The results demonstrated that ZG02 could significantly antagonize the high-fat diet/streptozotocin-induced fasting hyperglycemia, restore fasting blood insulin levels and also improve activity of G6PC in liver. The results from Western blot indicated that ZG02 significantly restored the expression level of phosphorylation AMPK, Sirt1 and PGC-1.

CONCLUSION

ZG02 improve hepatic glucose metabolism and insulin sensitivity via activation AMPK/Sirt1 signaling pathways in type 2 diabetes mice model.

Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT) rationale and design

Cardiovascular disease (CVD) is a major cause of morbidity and mortality. Although it has been widely appreciated that obesity is a major risk factor for CVD, treatments that produce effective, durable weight loss and the impact of weight reduction in reducing cardiovascular risk have been elusive. Instead, progress in CVD risk reduction has been achieved through medications indicated for controlling lipids, hyperglycemia, blood pressure, heart failure, inflammation, and/or thrombosis. Obesity has been implicated as promoting all these issues, suggesting that sustained, effective weight loss may have independent cardiovascular benefit. GLP-1 receptor agonists (RAs) reduce weight, improve glycemia, decrease cardiovascular events in those with diabetes, and may have additional cardioprotective effects. The GLP-1 RA semaglutide is in phase 3 studies as a medication for obesity treatment at a dose of 2.4 mg subcutaneously (s.c.) once weekly. Semaglutide Effects on Heart Disease and Stroke in Patients with Overweight or Obesity (SELECT) is a randomized, double-blind, parallel-group trial testing if semaglutide 2.4 mg subcutaneously once weekly is superior to placebo when added to standard of care for preventing major adverse cardiovascular events in patients with established CVD and overweight or obesity but without diabetes. SELECT is the first cardiovascular outcomes trial to evaluate superiority in major adverse cardiovascular events reduction for an antiobesity medication in such a population. As such, SELECT has the potential for advancing new approaches to CVD risk reduction while targeting obesity.

The novel dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide transiently delays gastric emptying similarly to selective long-acting GLP-1 receptor agonists

The effect of dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist (RA) tirzepatide on gastric emptying (GE) was compared to that of GLP-1RAs in non-clinical and clinical studies. GE was assessed following acute and chronic treatment with tirzepatide in diet-induced obese mice versus semaglutide or long-acting GIP analogue alone. Participants [with and without type 2 diabetes (T2DM)] from a phase 1, 4-week multiple dose study received tirzepatide, dulaglutide or placebo. GE was assessed by acetaminophen absorption. In mice, tirzepatide delayed GE to a similar degree to that achieved with semaglutide; however, these acute inhibitory effects were abolished after 2 weeks of treatment. GIP analogue alone had no effect on GE or on GLP-1's effect on GE. In participants with and without T2DM, once-weekly tirzepatide (≥5 and ≥4.5 mg, respectively) delayed GE after a single dose. This effect diminished after multiple doses of tirzepatide or dulaglutide in healthy participants. In participants with T2DM treated with an escalation schedule of tirzepatide 5/5/10/10 or 5/5/10/15 mg, a residual GE delay was still observed after multiple doses. These data suggest that tirzepatide's activity on GE is comparable to that of selective GLP-1RAs.

PT320, Sustained-Release Exendin-4, Mitigates L-DOPA-Induced Dyskinesia in a Rat 6-Hydroxydopamine Model of Parkinson's Disease

Background

We previously demonstrated that subcutaneous administration of PT320, a sustained-release (SR) form of exendin-4, resulted in the long-term maintenance of steady-state exenatide (exendin-4) plasma and target levels in 6-hydroxydopamine (6-OHDA)-pretreated animals. Additionally, pre- or post-treatment with PT320 mitigated the early stage of 6-OHDA-induced dopaminergic neurodegeneration. The purpose of this study was to evaluate the effect of PT320 on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced abnormal involuntary movements (AIMs) in the rat 6-OHDA model of Parkinson’s disease.

Methods

Adult male Sprague–Dawley rats were unilaterally lesioned in the right medial forebrain bundle by 6-OHDA. L-DOPA and benserazide were given daily for 22 days, starting from 4 weeks after lesioning. PT320 was co-administered weekly for 3 weeks. AIM was evaluated on days 1, 16, and 22 after initiating L-DOPA/benserazide + PT320 treatment. Brain tissues were subsequently collected for HPLC measurements of dopamine (DA) and metabolite concentrations.

Results

L-DOPA/benserazide increased AIMs of limbs and axial as well as the sum of all dyskinesia scores (ALO) over 3 weeks. PT320 significantly reduced the AIM scores of limbs, orolingual, and ALO. Although PT320 did not alter DA levels in the lesioned striatum, PT320 significantly attenuated 6-OHDA-enhanced DA turnover.

Conclusion

PT320 attenuates L-DOPA/benserazide-induced dyskinesia in a 6-OHDA rat model of PD and warrants clinical evaluation to mitigate Parkinson’s disease in humans.

Drug Delivery System in the Treatment of Diabetes Mellitus

Diabetes mellitus has been described as a chronic endocrine and metabolic disease, which is characterized by hyperglycemia and the coexistence of multiple complications. At present, the drugs widely applied in clinical treatment of diabetes mellitus mainly include insulin, insulin analogs, non-insulin oral hypoglycemic drugs and genetic drugs. Nevertheless, there is still no complete therapy strategy for diabetes mellitus management by far due to the intrinsic deficiencies of drugs and limits in administration routes such as the adverse reactions caused by long-term subcutaneous injection and various challenges in oral administration, such as enzymatic degradation, chemical instability and poor gastrointestinal absorption. Therefore, it is remarkably necessary to develop appropriate delivery systems and explore complete therapy strategies according to the characters of drugs and diabetes mellitus. Delivery systems have been found to be potentially beneficial in many aspects for effective diabetes treatment, such as improving the stability of drugs, overcoming different biological barriers in vivo to increase bioavailability, and acting as an intelligent automatized system to mimic endogenous insulin delivery and reduce the risk of hypoglycemia. This review aims to provide an overview related with the research advances, development trend of drug therapy and the application of delivery systems in the treatment diabetes mellitus, which could offer reference for the application of various drugs in the field of diabetes mellitus treatment.

Status and future directions of clinical trials in Parkinson's disease

Novel therapies are needed to treat Parkinson's disease (PD) in which the clinical unmet need is pressing. Currently, no clinically available therapeutic strategy can either retard or reverse PD or repair its pathological consequences. l-DOPA (levodopa) is still the gold standard therapy for motor symptoms yet symptomatic therapies for both motor and non-motor symptoms are improving. Many on-going, intervention trials cover a broad range of targets, including cell replacement and gene therapy approaches, quality of life improving technologies, and disease-modifying strategies (e.g., controlling aberrant α-synuclein accumulation and regulating cellular/neuronal bioenergetics). Notably, the repurposing of glucagon-like peptide-1 analogues with potential disease-modifying effects based on metabolic pathology associated with PD has been promising. Nevertheless, there is a clear need for improved therapeutic and diagnostic options, disease progression tracking and patient stratification capabilities to deliver personalized treatment and optimize trial design. This review discusses some of the risk factors and consequent pathology associated with PD and particularly the metabolic aspects of PD, novel therapies targeting these pathologies (e.g., mitochondrial and lysosomal dysfunction, oxidative stress, and inflammation/neuroinflammation), including the repurposing of metabolic therapies, and unmet needs as potential drivers for future clinical trials and research in PD.

Roles of Noncoding RNAs in Islet Biology

The discovery that most mammalian genome sequences are transcribed to ribonucleic acids (RNA) has revolutionized our understanding of the mechanisms governing key cellular processes and of the causes of human diseases, including diabetes mellitus. Pancreatic islet cells were found to contain thousands of noncoding RNAs (ncRNAs), including micro-RNAs (miRNAs), PIWI-associated RNAs, small nucleolar RNAs, tRNA-derived fragments, long non-coding RNAs, and circular RNAs. While the involvement of miRNAs in islet function and in the etiology of diabetes is now well documented, there is emerging evidence indicating that other classes of ncRNAs are also participating in different aspects of islet physiology. The aim of this article will be to provide a comprehensive and updated view of the studies carried out in human samples and rodent models over the past 15 years on the role of ncRNAs in the control of α- and β-cell development and function and to highlight the recent discoveries in the field. We not only describe the role of ncRNAs in the control of insulin and glucagon secretion but also address the contribution of these regulatory molecules in the proliferation and survival of islet cells under physiological and pathological conditions. It is now well established that most cells release part of their ncRNAs inside small extracellular vesicles, allowing the delivery of genetic material to neighboring or distantly located target cells. The role of these secreted RNAs in cell-to-cell communication between β-cells and other metabolic tissues as well as their potential use as diabetes biomarkers will be discussed. © 2020 American Physiological Society. Compr Physiol 10:893-932, 2020.

Acute Effects of Lixisenatide on Energy Intake in Healthy Subjects and Patients with Type 2 Diabetes: Relationship to Gastric Emptying and Intragastric Distribution

Glucagon-like peptide-1 receptor agonists induce weight loss, which has been suggested to relate to the slowing of gastric emptying (GE). In health, energy intake (EI) is more strongly related to the content of the distal, than the total, stomach. We evaluated the effects of lixisenatide on GE, intragastric distribution, and subsequent EI in 15 healthy participants and 15 patients with type 2 diabetes (T2D). Participants ingested a 75-g glucose drink on two separate occasions, 30 min after lixisenatide (10 mcg) or placebo subcutaneously, in a randomised, double-blind, crossover design. GE and intragastric distribution were measured for 180 min followed by a buffet-style meal, where EI was quantified. Relationships of EI with total, proximal, and distal stomach content were assessed. In both groups, lixisenatide slowed GE markedly, with increased retention in both the proximal (p < 0.001) and distal (p < 0.001) stomach and decreased EI (p < 0.001). EI was not related to the content of the total or proximal stomach but inversely related to the distal stomach at 180 min in health on placebo (r = -0.58, p = 0.03) but not in T2D nor after lixisenatide in either group. In healthy and T2D participants, the reduction in EI by lixisenatide is unrelated to changes in GE/intragastric distribution, consistent with a centrally mediated effect.

Assessing the Continuation of Glucagon-Like Peptide-1 Receptor Agonists When Weight and HBA1C Are Not Reduced

Background: Glucagon-like peptide-1 agonists (GLP-1) reportedly lower HbA1c and promote weight reduction and improve cardiovascular outcomes. The primary objective of this study was to evaluate the use of GLP-1 agents in patients and changes in HbA1c, weight loss, blood pressure, and lipoid profiles. Methods: Patient information was extracted from a regional Veteran Affairs data mart. Patients were included if they had prescriptions for at least 90 days of a GLP-1 between April 1, 2005, and December 1, 2016, and HbA1Cs and weights at both baseline and within first 15 months of therapy. Blood pressure and lipids were also measured. Pearson's correlation and multiple regression analysis were used. Results: Three hundred twenty-two patients met inclusion criteria. Average HbA1c decreased by 0.81% and weight by 4.4 kg. At 1 year, 160 patients had both weight and HbA1c measured, and of those, 92 (58%) patients had HbA1c reduction of at least 0.5% and 94 (59%) patients had <-2 kg change in weight. Fifty-seven (36%) patients met both of those outcomes. Veterans who met both weight and HbA1c outcomes were slightly, but significantly, older than those who did not meet both. No correlation was found between weight and HbA1c change at each quarter (P > 0.05); however, weight change was correlated with systolic blood pressure change (P = 0.03). Multiple regression for meeting weight and HbA1c target outcomes, and changes at quarters 1-3, all correlated to success at 1 year (P < 0.05). Conclusions: Weight change was independent of HbA1c changes in patients receiving GLP-1s for diabetes control. Weight loss was associated with decreases in systolic BP.

Connecting the Dots Between Inflammatory Bowel Disease and Metabolic Syndrome: A Focus on Gut-Derived Metabolites

The role of the microbiome in health and disease has gained considerable attention and shed light on the etiology of complex diseases like inflammatory bowel disease (IBD) and metabolic syndrome (MetS). Since the microorganisms inhabiting the gut can confer either protective or harmful signals, understanding the functional network between the gut microbes and the host provides a comprehensive picture of health and disease status. In IBD, disruption of the gut barrier enhances microbe infiltration into the submucosae, which enhances the probability that gut-derived metabolites are translocated from the gut to the liver and pancreas. Considering inflammation and the gut microbiome can trigger intestinal barrier dysfunction, risk factors of metabolic diseases such as insulin resistance may have common roots with IBD. In this review, we focus on the overlap between IBD and MetS, and we explore the role of common metabolites in each disease in an attempt to connect a common origin, the gut microbiome and derived metabolites that affect the gut, liver and pancreas.

Liraglutide accelerates colonic transit in people with type 1 diabetes and polyneuropathy: A randomised, double-blind, placebo-controlled trial

BACKGROUND

Glucagon-like peptide-1 receptor agonists, such as liraglutide, reduce hyperglycaemia and induce weight loss and are used as a treatment in diabetes. However, common adverse effects include nausea, loss of appetite and prolonged gastric emptying. It is not known whether these changes are centrally generated or if liraglutide alters the enteric motility.

OBJECTIVE

To investigate the effects of liraglutide on gastrointestinal function and symptoms.

METHODS

A total of 48 adults with type 1 diabetes and confirmed distal symmetric polyneuropathy were randomised to receive liraglutide 1.8 mg/day or placebo for 26 weeks. Regional transit times and motility indexes were assessed with a wireless motility capsule, whereas symptoms were evaluated using the validated gastroparesis cardinal symptom index.

RESULTS

Liraglutide treatment reduced large bowel transit time (31.7%, p = 0.04) and decreased motility index (6.1%, p = 0.04) compared to placebo, whereas the groups did not differ in gastric emptying or small-bowel transit times. Liraglutide increased postprandial fullness with 29% (p = 0.01). Increased small bowel transit time was associated with decreased bloating (p = 0.008).

CONCLUSION

Liraglutide accelerates large bowel transit and decreases motility index, which may indicate better coordination of propulsive motility. This potentially improves the function of the enteric nervous system, leading to normalised colonic function and positive effects in type 1 diabetes.

Novel glucose lowering agents are associated with a lower risk of cardiovascular and adverse events in type 2 diabetes: A population based analysis

BACKGROUND

Recent randomized control trials have described a protective cardiovascular effect of novel glucose lowering drugs in patients at high cardiovascular risk. Whether these second-line agents have similar effects in the general population is unknown. We aimed to compare the risk of major cardiovascular and adverse events in new users of sodium-glucose cotransporter-2 inhibitors (SGLT-2i), dipeptidyl peptidase-4 inhibitor (DPP-4i), glucagon-like peptide 1 agonist (GLP-1a), and sulfonylurea in T2DM patients not controlled on metformin therapy.

METHODS

Retrospective cohort study using the MarketScan database (2011-2015). We selected T2DM individuals who were newly dispensed sulfonylureas, SGLT-2i, DPP-4i, or GLP-1a, as second-line therapy, added to metformin. Cohort entry was defined by date of first prescription of the second-line agent. Time to first non-fatal cardiovascular or adverse event was compared using Cox regression models adjusted for confounders.

RESULTS

Among 118,341 T2DM patients using metformin (mean age: 56), most were at low cardiovascular risk (4% with previous cardiovascular or cerebrovascular event). During a median follow-up of 10 months compared with sulfonylureas users, cardiovascular risk was lower in users of SGLT-2i (aHR = 0.61; 95% CI: 0.40-0.97), DPP-4i (aHR = 0.79; 95% CI: 0.69-0.90) and GLP-1a (aHR = 0.65; 95% CI: 0.48-0.89). Serious adverse events were rare but compared with sulfonylurea, the risk was lower in new users of novel glucose lowering agents.

CONCLUSION

In our analyses, which included patients with and without prior cardiovascular disease, initiating novel glucose lowering drugs as second-line therapy for T2DM was associated with a lower risk of cardiovascular and adverse events than sulfonylurea initiation.

Recent advances in understanding the role of glucagon-like peptide 1

The discovery that glucagon-like peptide 1 (GLP-1) mediates a significant proportion of the incretin effect during the postprandial period and the subsequent observation that GLP-1 bioactivity is retained in type 2 diabetes (T2D) led to new therapeutic strategies being developed for T2D treatment based on GLP-1 action. Although owing to its short half-life exogenous GLP-1 has no use therapeutically, GLP-1 mimetics, which have a much longer half-life than native GLP-1, have proven to be effective for T2D treatment since they prolong the incretin effect in patients. These GLP-1 mimetics are a desirable therapeutic option for T2D since they do not provoke hypoglycaemia or weight gain and have simple modes of administration and monitoring. Additionally, over more recent years, GLP-1 action has been found to mediate systemic physiological beneficial effects and this has high clinical relevance due to the post-diagnosis complications of T2D. Indeed, recent studies have found that certain GLP-1 analogue therapies improve the cardiovascular outcomes for people with diabetes. Furthermore, GLP-1-based therapies may enable new therapeutic strategies for diseases that can also arise independently of the clinical manifestation of T2D, such as dementia and Parkinson's disease. GLP-1 functions by binding to its receptor (GLP-1R), which expresses mainly in pancreatic islet beta cells. A better understanding of the mechanisms and signalling pathways by which acute and chronic GLP-1R activation alleviates disease phenotypes and induces desirable physiological responses during healthy conditions will likely lead to the development of new therapeutic GLP-1 mimetic-based therapies, which improve prognosis to a greater extent than current therapies for an array of diseases.

Liraglutide Protects Against Brain Amyloid-β1-42 Accumulation in Female Mice with Early Alzheimer's Disease-Like Pathology by Partially Rescuing Oxidative/Nitrosative Stress and Inflammation

Alzheimer’s disease (AD) is the most common form of dementia worldwide, being characterized by the deposition of senile plaques, neurofibrillary tangles (enriched in the amyloid beta (Aβ) peptide and hyperphosphorylated tau (p-tau), respectively) and memory loss. Aging, type 2 diabetes (T2D) and female sex (especially after menopause) are risk factors for AD, but their crosslinking mechanisms remain unclear. Most clinical trials targeting AD neuropathology failed and it remains incurable. However, evidence suggests that effective anti-T2D drugs, such as the GLP-1 mimetic and neuroprotector liraglutide, can be also efficient against AD. Thus, we aimed to study the benefits of a peripheral liraglutide treatment in AD female mice. We used blood and brain cortical lysates from 10-month-old 3xTg-AD female mice, treated for 28 days with liraglutide (0.2 mg/kg, once/day) to evaluate parameters affected in AD (e.g., Aβ and p-tau, motor and cognitive function, glucose metabolism, inflammation and oxidative/nitrosative stress). Despite the limited signs of cognitive changes in mature female mice, liraglutide only reduced their cortical Aβ_1–42 levels. Liraglutide partially attenuated brain estradiol and GLP-1 and activated PKA levels, oxidative/nitrosative stress and inflammation in these AD female mice. Our results support the earlier use of liraglutide as a potential preventive/therapeutic agent against the accumulation of the first neuropathological features of AD in females.

Efficacy and Safety of Once-Weekly Dulaglutide in Type 2 Diabetes Patients Using Insulin: Exploratory Subgroup Analysis by Insulin Regimen

PURPOSE

In East Asian patients, type 2 diabetes mellitus (T2DM) is characterized primarily by β-cell dysfunction, with lower insulin secretion than in Caucasian individuals. Therefore, bolus insulin and premixed insulin containing a bolus insulin component are important therapeutic tools in Japan, in addition to basal insulin. This subgroup analysis is stratified by insulin regimen and uses data from a phase 4, randomized, placebo-controlled, double-blind and subsequent open-label study in Japan to assess the efficacy and safety of once-weekly dulaglutide combined with various insulin therapies.

METHODS

This multicenter study enrolled Japanese patients with T2DM and inadequate glycemic control [glycated hemoglobin A1c (HbA1c) ≥ 7.5% to ≤ 10.5%] on insulin therapy [basal (B), premixed (PM), or basal bolus (BB)] in combination with or without one or two oral antidiabetic agents. Randomized participants received once-weekly dulaglutide 0.75 mg (n = 120) or placebo (n = 39) during a 16-week double-blind treatment period, and dulaglutide during a 36-week open-label extension. In this subgroup analysis, efficacy measures were changes from baseline in HbA1c, 7-point self-monitored blood glucose profiles, and body weight. Safety measures were incidence of adverse events and hypoglycemia during the first 16 weeks.

RESULTS

At week 16, least squares mean differences (95% CI) regarding changes from baseline in HbA1c for each insulin regimen versus placebo were: B: - 1.62% (- 1.96, - 1.28), PM: - 1.78% (- 2.25, - 1.30), and BB: - 1.15% (- 1.54, - 0.77); p < 0.001 dulaglutide vs. placebo for each subgroup. No significant differences in body weight changes were observed between dulaglutide and placebo for any insulin regimen. Gastrointestinal symptoms were the most commonly observed adverse events in dulaglutide-treated patients. Hypoglycemia incidence rates were: B: dulaglutide 38.5% vs. placebo 23.5%; PM: dulaglutide 38.5% vs. placebo 44.4%; BB: dulaglutide 50.0% vs. placebo 30.8%.

CONCLUSIONS

Overall, dulaglutide was generally well tolerated and improved glycemic control significantly versus placebo, regardless of insulin regimen.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02750410.

Differential indication for SGLT-2 inhibitors versus GLP-1 receptor agonists in patients with established atherosclerotic heart disease or at risk for congestive heart failure

SGLT-2 inhibitors and most GLP-1 receptor agonists demonstrated cardiovascular superiority and reduction of cardiovascular and overall mortality. These results stand as a turning point in the management of diabetes, shifting the focus from controlling glucose levels to mastering the extra-glycemic effects of these new drugs. This narrative review will discuss recent CVOT with focus on SGLT-2 inhibitors and GLP-1 receptor agonists to distinguish relevant patients' characteristics as potential predictors for therapeutic efficacy. It will also examine their efficacy and safety, the differences in their cardiovascular and renal benefits, aiming to convey clinical suggestions for everyday practice.

Selection and progression of unimolecular agonists at the GIP, GLP-1, and glucagon receptors as drug candidates

The continued global growth in the prevalence of obesity coupled with the limited number of efficacious and safe treatment options elevates the importance of innovative pharmaceutical approaches. Combinatorial strategies that harness the metabolic benefits of multiple hormonal mechanisms have emerged at the preclinical and more recently clinical stages of drug development. A priority has been anti-obesity unimolecular peptides that function as balanced, high potency poly-agonists at two or all the cellular receptors for the endocrine hormones glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon. This report reviews recent progress in this area, with emphasis on what the initial clinical results demonstrate and what remains to be addressed.

Once-Weekly Dulaglutide with Insulin Therapy for Type 2 Diabetes: Efficacy and Safety Results from a Phase 4, Randomized, Placebo-Controlled Study

INTRODUCTION

Although global studies have investigated the combination of dulaglutide with insulin in patients with type 2 diabetes mellitus (T2DM), differences in lean body mass and dulaglutide dosing can complicate the extrapolation of global study results to Japanese patients. This phase 4, randomized, placebo-controlled, double-blind, and subsequent open-label study aimed to assess the efficacy and safety of once-weekly dulaglutide 0.75 mg in combination with insulin therapy in patients with T2DM.

METHODS

Patients enrolled in this multicenter study were Japanese with T2DM who had inadequate glycemic control (HbA1c 7.5-10.5%) with insulin therapy (basal insulin, premixed insulin, or basal/mealtime insulin) in combination with or without one or two oral antidiabetic agents (OADs). Patients were randomized in a 3:1 ratio to dulaglutide or placebo. The first 16 weeks was the double-blind period with stable insulin dosing, and patients taking placebo were switched to dulaglutide for an additional 36-week open-label period in which all patients took dulaglutide (52 weeks total).

RESULTS

Patients (N = 159) were randomized to dulaglutide (n = 120) or placebo (n = 39). The least-squares (LS) mean changes from baseline in HbA1c at week 16 were dulaglutide - 1.45% and placebo 0.06%. The LS mean and 95% confidence interval for the difference were - 1.50% (- 1.73%, - 1.28%) and dulaglutide was superior to placebo. There were no significant differences between treatment groups in changes from baseline in body weight and insulin dose. The most frequently observed treatment-emergent adverse events in dulaglutide were nasopharyngitis, constipation, abdominal discomfort, nausea, and decreased appetite. The incidence rates of hypoglycemic events by week 16 were dulaglutide 42.5% and placebo 30.8% (P = 0.258).

CONCLUSION

Once-weekly dulaglutide 0.75 mg was superior to once-weekly placebo in glycemic control improvement and well tolerated in patients with T2DM in combination with insulin therapy with or without OADs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02750410.

FUNDING

Eli Lilly and Company.

The Effects of DPP-4 Inhibitors, GLP-1RAs, and SGLT-2/1 Inhibitors on Heart Failure Outcomes in Diabetic Patients With and Without Heart Failure History: Insights From CVOTs and Drug Mechanism

Patients with type 2 diabetes (T2D) have a higher risk of heart failure (HF) than healthy people, and the prognosis of patients with diabetes and current or previous HF is worse than that of patients with only diabetes. We reviewed the HF outcomes in recently published cardiovascular outcome trials (CVOTs) of three new classes of anti-diabetic agents, namely, dipeptidyl peptidase-4 inhibitors (DPP-4is), glucagon-like-peptide 1 receptor agonists (GLP-1RAs), and sodium glucose cotransporter-2 inhibitors (SGLT-2is) or SGLT-2 and SGLT-1 dual inhibitors and divided the patients into two groups based on the history of HF (with or without) and analyzed their risks of HHF based on the receipt of the aforementioned anti-diabetes drug types. Since the follow-up period differed among the trials, we expressed the rate of HHF as events/1,000 person-years to describe the HF outcome. At last we pooled the data and analyzed their different effects and mechanisms on heart failure outcomes. Although DPP-4is did not increase the risk of HHF in T2D patients with a history of HF, they were associated with a significantly higher risk of HHF among patients without history of HF. Some GLP-1RAs reduced the risk of macrovascular events, but none of these drugs reduced the risk of HHF in patients with T2D irrespective of their HF history. It was not clarified whether SGLT-1/2is can improve the prognosis of macrovascular events in patients with T2D, but these drugs reduced the risk of HHF regardless of patients' histories of HF. This information may be useful or referential for the "precise" selection of hyperglycemic medications. Further researches still needed to clarify the mechanisms of these anti-diabetic medications.

Renal Benefits of SGLT 2 Inhibitors and GLP-1 Receptor Agonists: Evidence Supporting a Paradigm Shift in the Medical Management of Type 2 Diabetes

Diabetic nephropathy (DN) is one of the most perilous side effects of diabetes mellitus type 1 and type 2 (T1DM and T2DM).). It is known that sodium/glucose cotransporter 2 inhibitors (SGLT 2i) and glucagone like peptide-1 receptor agonists (GLP-1 RAs) have renoprotective effects, but the molecular mechanisms are still unknown. In clinical trials GLP-1 analogs exerted important impact on renal composite outcomes, primarily on macroalbuminuria, possibly through suppression of inflammation-related pathways, however enhancement of natriuresis and diuresis is also one of possible mechanisms of nephroprotection. Dapagliflozin, canagliflozin, and empagliflozin are SGLT2i drugs, useful in reducing hyperglycemia and in their potential renoprotective mechanisms, which include blood pressure control, body weight loss, intraglomerular pressure reduction, and a decrease in urinary proximal tubular injury biomarkers. In this review we have discussed the potential synergistic and/or additive effects of GLP 1 RA and SGLT2 inhibitors on the primary onset and progression of kidney disease, and the potential implications on current guidelines of diabetes type 2 management.

Pharmacokinetics of Exenatide in nonhuman primates following its administration in the form of sustained-release PT320 and Bydureon

The time-dependent (30 min - day 84) plasma profile of PT320, a sustained-release (SR)-Exenatide formulation under clinical development for treatment of neurodegenerative disorders, was evaluated in nonhuman primates after a single subcutaneous dose and was compared to Bydureon. Exenatide release from PT320 exhibited a triphasic pharmacokinetic profile. An initial peak occurred at 3 hr post-administration, a secondary peak at 5 days, and achievement of Exenatide steady-state plasma levels from day 10–28. Systemic exposure increased across PT320 doses, and Exenatide levels were maintained above the therapeutic threshold prior to achieving a steady-state. In contrast, Exenatide release from Bydureon exhibited a biphasic profile, with an initial plasma peak at 3 hr, followed by a rapid decline to a sub-therapeutic concentration, and a gradual elevation to provide a steady-state from day 35–49. Exenatide total exposure, evaluated from the area under the time-dependent Exenatide concentration curve, was similar for equivalent doses of PT320 and Bydureon. The former, however, reached and maintained steady-state plasma Exenatide levels more rapidly, without dipping to a sub-therapeutic concentration. Both SR-Exenatide formulations proved well-tolerated and, following a well-regulated initial release burst, generated steady-state plasma levels of Exenatide, but with PT320 producing continuous therapeutic Exenatide levels and more rapidly reaching a steady-state.

The Effects of a Whey Protein and Guar Gum-Containing Preload on Gastric Emptying, Glycaemia, Small Intestinal Absorption and Blood Pressure in Healthy Older Subjects

A whey protein/guar gum preload reduces postprandial glycaemia in type 2 diabetes through slowing gastric emptying. However, gastric emptying has previously been assessed using a stable isotope breath test technique, which cannot discriminate between slowing of gastric emptying and small intestinal absorption. This preload also may be useful in the management of postprandial hypotension. We evaluated the effects of a whey protein/guar preload on gastric emptying, glucose absorption, glycaemic/insulinaemic and blood pressure (BP) responses to an oral glucose load. Eighteen healthy older participants underwent measurements of gastric emptying (scintigraphy), plasma glucose and insulin, glucose absorption, superior mesenteric artery (SMA) flow, BP and heart rate (HR) after ingesting a 50 g glucose drink, with or without the preload. The preload reduced plasma glucose (p = 0.02) and serum 3-O-methylglucose (3-OMG) (p = 0.003), and increased plasma insulin (p = 0.03). There was no difference in gastric emptying or BP between the two days. The reduction in plasma glucose on the preload day was related to the reduction in glucose absorption (r = 0.71, p = 0.002). In conclusion, the glucose-lowering effect of the preload may relate to delayed small intestinal glucose absorption and insulin stimulation, rather than slowing of gastric emptying.

GLP-1 receptor agonists and risk of cancer in type 2 diabetes: an updated meta-analysis of randomized controlled trials

PURPOSE

Some preliminary studies reported a link between GLP-1 receptor agonists (GLP-1RAs) and thyroid/pancreatic neoplasms, while its human relevance remained undetermined. The present meta-analysis was performed to collect information on cancers associated with GLP-1RAs in patients with type 2 diabetes mellitus (T2DM).

METHODS

Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and ClinicalTrials.gov were extensively searched to identify randomized controlled trials that reported cancer events in T2DM patients treated with GLP-1RAs for at least 52 weeks, up to March 18, 2019. Odds ratio (OR) with 95% Confidence Interval (CI) was calculated for overall cancer (primary outcome), thyroid and pancreatic cancer.

RESULTS

A total of 37 eligible trials were identified. The OR for overall cancer associated with GLP-1RAs was 1.03 (95% CI 0.95-1.12; p = 0.41) compared with comparators. Subgroup analyses showed that treatment with albiglutide was associated with a lower risk of overall cancer (OR 0.76 [95% CI 0.60-0.97]; p = 0.03), and no elevated risk of overall cancer was identified for other GLP-1RAs. No significant differences in the risks of thyroid nor pancreatic cancer were disclosed between GLP-1RAs and comparators.

CONCLUSIONS

This meta-analysis did not suggest any increased risk of cancers associated with GLP-1RAs use in T2DM. The reduction in the risk of overall cancer associated with albiglutide needs to be examined further.

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

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

Combination therapy with SGLT-2 inhibitors and GLP-1 receptor agonists as complementary agents that address multi-organ defects in type 2 diabetes

Type 2 diabetes (T2D) has a complex pathophysiology composed of multiple underlying defects that lead to impaired glucose homeostasis and the development of macrovascular and microvascular complications. Of the currently available glucose-lowering therapies, sodium-glucose cotransporter-2 inhibitors (SGLT-2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) both provide effective glycemic control and have been shown to reduce cardiovascular (CV) events in patients with T2D and a high CV risk or established CV disease. Because these agents have complementary mechanisms of action, they are able to act on multiple defects of T2D when used in combination. This review discusses the rationale for and potential benefits of SGLT-2i plus GLP-1RA combination therapy in patients with T2D. A search of the PubMed database was conducted for studies and reviews describing the combined use of SGLT-2is and GLP-1RAs, with a specific focus on identifying clinical studies of combination therapy in patients with T2D. In clinical studies, glycated hemoglobin (A1c) was significantly reduced over 28-52 weeks with SGLT-2i plus GLP-1RA therapy versus the individual agents or baseline. Several CV risk factors, including body weight, blood pressure, and lipid parameters, were also improved. SGLT-2i plus GLP-1RA therapy was generally well tolerated, with a low risk of hypoglycemia and no unexpected findings. Taken together with results from large CV outcomes trials of SGLT-2is and GLP-1RAs, combination therapy with these agents potentially provides effective durable glycemic control and CV benefits due to their complementary actions on the defects of T2D.

Glucagon-like peptide-1 receptor agonists and risk of bone fracture in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

AIMS

To evaluate the association between glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and the risk of bone fracture in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

We conducted a systematic literature search in PubMed, Embase, the Cochrane Library, and Web of Science from inception to 28 February 2018 and identified eligible randomized controlled trials. The following data were extracted from each study: first author, year of publication, sample size, patient characteristics, study design, intervention drug, control drug, follow-up time, and incident bone fracture events. A meta-analysis was conducted using Review Manager 5.3 software to calculate the odds ratio (OR) and 95% confidence intervals (CI) for dichotomous variables.

RESULTS

A total of 38 studies with 39 795 patients with T2DM were included. There were 241 incident bone fracture cases (107 in the GLP-1 RAs group and 134 in the control group). Compared with patients who received placebo and other anti-diabetic drugs, those who received GLP-1 RAs treatment showed a pooled OR of 0.71 (95% CI, 0.56-0.91) for bone fracture. Subgroup analysis showed that treatments with liraglutide and lixisenatide were associated with significantly reduced risk of bone fractures (ORs, 0.56; 95% CI, 0.38-0.81 and 0.55; 95% CI, 0.31-0.97, respectively). However, other GLP-1 RAs did not show superiority to placebo or other anti-diabetic drugs. Moreover, these beneficial effects were dependent on the duration of GLP-1 RAs treatment, only a GLP-1 RAs treatment period of more than 52 weeks could significantly lower the risk of bone fracture in patients with T2DM (OR, 0.71; 95% CI, 0.56-0.91).

CONCLUSIONS

Compared with placebo and other anti-diabetic drugs, liraglutide and lixisenatide were associated with a significant reduction in the risk of bone fractures, and the beneficial effects were dependent on the duration of treatment.

Cardiovascular Outcome Trials in Type 2 Diabetes: What Do They Mean for Clinical Practice?

IN BRIEF Cardiovascular disease is the leading cause of morbidity and mortality in people with diabetes, and deaths from heart disease are two to four times higher among adults with type 2 diabetes. Trials such as the U.K. Prospective Diabetes Study, ACCORD (Action to Control Cardiovascular Risk in Diabetes), ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation), and VADT (Veteran's Affairs Diabetes Trial) produced mixed findings regarding whether intensive glycemic control results in improved cardiovascular (CV) outcomes for patients with diabetes. In response to concerns, including the CV safety of the thiazolidinedione rosiglitazone, the U.S. Food and Drug Administration and subsequently the European Medicines Agency issued guidance that trials should be conducted to prove that antihyperglycemic agents have acceptable CV risk profiles. In this article, the authors review the study designs and results of CV outcomes trials conducted with sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists and discuss how these may affect clinical practice.

Controlling Obesity and Metabolic Diseases by Hydrodynamic Delivery of a Fusion Gene of Exendin-4 and α1 Antitrypsin

Obesity and associated metabolic comorbidities represent a growing public health problem. In this study, we demonstrate the use of a newly created fusion gene of exendin-4 and α1-antitrypsin to control obesity and obesity-associated metabolic disorders including insulin resistance, fatty liver and hyperglycemia. The fusion gene encodes a protein with exendin-4 peptide placed at the N-terminus of human α-1 antitrypsin, and is named EAT. Hydrodynamic transfer of the EAT gene to mice prevents high-fat diet-induced obesity, insulin resistance and fatty liver development. In diet-induced obese mice, expression of EAT gene induces weight loss, improves glucose homeostasis, and attenuates hepatic steatosis. In ob/ob mice, EAT gene transfer suppresses body weight gain, maintains metabolic homeostasis, and completely blocks fatty liver development. Six-month overexpression of the EAT fusion gene in healthy mice does not lead to any detectable toxicity. Mechanistic study reveals that the resulting metabolic benefits are achieved by a reduced food take and down-regulation of transcription of pivotal genes responsible for lipogenesis and lipid droplet formation in the liver and chronic inflammation in visceral fat. These results validate the feasibility of gene therapy in preventing and restoring metabolic homeostasis under diverse pathologic conditions, and provide evidence in support of a new strategy to control obesity and related metabolic diseases.

Once-Weekly Efpeglenatide Dose-Range Effects on Glycemic Control and Body Weight in Patients With Type 2 Diabetes on Metformin or Drug Naive, Referenced to Liraglutide

OBJECTIVE

To explore the efficacy, safety, and tolerability of once-weekly efpeglenatide, a long-acting glucagon-like peptide 1 receptor agonist (GLP-1 RA), in early type 2 diabetes (T2D) (drug naive or on metformin monotherapy).

RESEARCH DESIGN AND METHODS

EXCEED 203 was a 12-week, randomized, placebo-controlled, double-blind, parallel-group, dose-ranging study of efpeglenatide once weekly referenced to open-label liraglutide 1.8 mg (exploratory analysis). Participants, ∼90% on metformin monotherapy, were randomized to one of five efpeglenatide doses (0.3, 1, 2, 3, or 4 mg q.w.; n = 181), placebo (n = 37), or liraglutide (≤1.8 mg daily; n = 36). The primary efficacy end point was change in HbA_1c from baseline to week 13.

RESULTS

From a baseline HbA_1c of 7.7-8.0% (61.0-63.9 mmol/mol), all efpeglenatide doses ≥1 mg significantly reduced HbA_1c versus placebo (placebo-adjusted least squares [LS] mean changes 0.6-1.2%, P < 0.05 for all) to a final HbA_1c of 6.3-6.8% (45.4-50.6 mmol/mol); masked efpeglenatide 4 mg was noninferior to open-label liraglutide. Greater proportions treated with efpeglenatide ≥1 mg than placebo achieved HbA_1c <7% (61-72% vs. 24%, P < 0.05 for all), and greater reductions in body weight were observed with efpeglenatide 3 and 4 mg versus placebo (placebo-adjusted LS mean differences -1.4 and -2.0 kg, respectively, P < 0.05 for both). Rates of nausea and vomiting were consistent with other GLP-1 RAs and rapidly subsided after the initial 2 weeks. No neutralizing antibodies were detected with efpeglenatide.

CONCLUSIONS

Efpeglenatide once weekly led to significant reductions in HbA_1c and weight, with a safety profile consistent with the GLP-1 RA class in patients with early T2D mostly on metformin monotherapy.

Heterogeneity and Similarities in GLP-1 Receptor Agonist Cardiovascular Outcomes Trials

The latest recommendations from the American Diabetes Association and the European Association for the Study of Diabetes prioritize the use of drugs with proven cardiovascular (CV) benefit in patients with established CV disease. Especially among the glucagon-like peptide (GLP)-1 receptor agonists (GLP-1RA) class, results of cardiovascular outcomes trials (CVOT) have been heterogeneous. Baseline characteristics of the population, study design, drugs in the control arm, modifications of CV risk factors, including glycemic control, reduction of hypoglycemia, and the GLP-1RA direct effects on CV cells and tissues, were considered. Ultimately, the time of exposure to the GLP-1RA appears to be the factor most prominently explaining trial heterogeneity. Thus, the CV benefit should be regarded as a class effect of GLP-1RA, as largely similar results are seen for drugs sharing a common mechanism of action.

GLP-1 RA Treatment and Dosing Patterns Among Type 2 Diabetes Patients in Six Countries: A Retrospective Analysis of Pharmacy Claims Data

INTRODUCTION

The glucagon-like peptide-1 receptor agonist (GLP-1 RA) class is evolving and expanding. This retrospective database study evaluated recent real-world treatment and dosing patterns of patients with type 2 diabetes (T2D) initiating GLP-1 RAs in Belgium (BE), France (FR), Germany (DE), Italy (IT), the Netherlands (NL), and Canada (CA).

METHODS

Adult T2D patients initiating GLP-1 RA therapy (dulaglutide [DULA], exenatide twice daily [exBID], exenatide once weekly [exQW], liraglutide [LIRA], or lixisenatide [LIXI]) from 2015 to 2016 were identified using the IQVIA (IQVIA, Durham, NC, and Danbury, CT, USA) Real-World Data Adjudicated Pharmacy Claims. The therapy initiation date was termed the 'index date.' Eligible patients had ≥ 180 days pre-index and ≥ 360 days post-index. Persistence (until discontinuation or switch) was evaluated over the variable follow-up using Kaplan-Meier (KM) survival analysis. Average daily dose (ADD) was calculated until discontinuation or switch.

RESULTS

A total of 34,649 DULA, 3616 exBID, 11,138 exQW, 48,317 LIRA, and 2,204 LIXI patients were included in the analysis (34.9-63.2% female; median age range 53-62 years; median follow-up 16-30 months). Proportion persistent at 1-year post-index was 36.8-67.2% for DULA, 5.9-44.4% for exBID, 24.7-44.2% for exQW, 22.2-57.5% for LIRA, and 15.5-40.0% for LIXI. Median time persistent (days) was 245-381 for DULA, 62-243 for exBID, 121-319 for exQW, 103-507 for LIRA, and 99-203 for LIXI. Mean ADD was 13.21-20.43 µg for exBID, 1.44-1.68 mg for LIRA, and 19.88-20.54 µg for LIXI. Mean average weekly dose (AWD) ranged from 2.03 to 2.14 mg for exQW. Mean AWD for DULA was 1.25 mg in Canada and ranged from 1.43 to 1.53 mg in the other countries.

CONCLUSION

Across six countries, persistence was highest among DULA patients and generally lowest among exBID patients. ADD/AWD for all GLP-1 RAs was in line with the recommended label. Longer-term data would be useful to obtain a better understanding of GLP-1 RA treatment patterns over time.

FUNDING

Eli Lilly and Company, Indianapolis, IN, USA.

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.

Central GLP-1 receptors: Novel molecular targets for cocaine use disorder

Given that the search for effective pharmacotherapies for cocaine use disorder has, thus far, been fruitless, there remains a critical need for conceptually innovative approaches toward identifying new medications to treat this disease. A better understanding of the neurocircuits and neurobiological mechanisms underlying cocaine taking and seeking may identify molecular substrates that could serve as targets for novel pharmacotherapies to treat cocaine use disorder. Recent preclinical evidence suggests that glucagon-like peptide-1 (GLP-1) receptor agonists could be re-purposed to treat cocaine craving-induced relapse. This review endeavors to comprehensively summarize the current literature investigating the efficacy of GLP-1 receptor agonists in reducing the rewarding and reinforcing effects of cocaine in animal models of cocaine use disorder. The role of central endogenous GLP-1 circuits in voluntary cocaine taking and seeking is also discussed. Behavioral, neurochemical, electrophysiological and molecular biology studies indicate that central GLP-1 receptor activation functionally modulates the mesolimbic reward system and decreases addiction-like phenotypes in rodents. Overall, an emerging preclinical literature provides compelling evidence to advance GLP-1 receptor agonists into clinical trials testing the efficacy of these medications in preventing cocaine craving-induced relapse.

Understanding the Mechanism of Action and Clinical Implications of Anti-Obesity Drugs Recently Approved in Korea

The Korean Ministry of Food and Drug Safety has approved three anti-obesity drugs for long-term management in the past decade. In addition, since 2019, bariatric surgery has been financially supported by National Health Insurance Service in Korea. In this review, the mechanisms of action and the clinical implications of the recently approved anti-obesity drugs, lorcaserin, naltrexone/bupropion, and liraglutide are explained. Lorcaserin stimulates proopiomelanocortin (POMC)/cocaine- and amphetamine-regulated transcript (CART) neurons and inhibits neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons, which results in the activation of melanocortin 3/4 receptors. Naltrexone/bupropion stimulates POMC neurons through bupropion; this stimulation is augmented by blocking the autoinhibitory mechanism of POMC with naltrexone. The hypophagic effect of liraglutide is mediated through the direct activation of POMC/CART neurons and the indirect suppression of NPY/AgRP neurons through γ-aminobutyric acid-dependent signaling, with adjunctive suppression of the mesolimbic dopamine reward system. In addition to liraglutide, another glucagon-like peptide-1 receptor agonist, semaglutide, is expected to be added to the list of anti-obesity drugs in the near future. In patients with obesity and high cardiovascular risk, lorcaserin was considered neutral and liraglutide was considered favorable, whereas inconclusive results were obtained for naltrexone/bupropion.

Diabetes pharmacotherapy and effects on the musculoskeletal system

Persons with type 1 or type 2 diabetes have a significantly higher fracture risk than age-matched persons without diabetes, attributed to disease-specific deficits in the microarchitecture and material properties of bone tissue. Therefore, independent effects of diabetes drugs on skeletal integrity are vitally important. Studies of incretin-based therapies have shown divergent effects of different agents on fracture risk, including detrimental, beneficial, and neutral effects. The sulfonylurea class of drugs, owing to its hypoglycemic potential, is thought to amplify the risk of fall-related fractures, particularly in the elderly. Other agents such as the biguanides may, in fact, be osteo-anabolic. In contrast, despite similarly expected anabolic properties of insulin, data suggests that insulin pharmacotherapy itself, particularly in type 2 diabetes, may be a risk factor for fracture, negatively associated with determinants of bone quality and bone strength. Finally, sodium-dependent glucose co-transporter 2 inhibitors have been associated with an increased risk of atypical fractures in select populations, and possibly with an increase in lower extremity amputation with specific SGLT2I drugs. The role of skeletal muscle, as a potential mediator and determinant of bone quality, is also a relevant area of exploration. Currently, data regarding the impact of glucose lowering medications on diabetes-related muscle atrophy is more limited, although preclinical studies suggest that various hypoglycemic agents may have either aggravating (sulfonylureas, glinides) or repairing (thiazolidinediones, biguanides, incretins) effects on skeletal muscle atrophy, thereby influencing bone quality. Hence, the therapeutic efficacy of each hypoglycemic agent must also be evaluated in light of its impact, alone or in combination, on musculoskeletal health, when determining an individualized treatment approach. Moreover, the effect of newer medications (potentially seeking expanded clinical indication into the pediatric age range) on the growing skeleton is largely unknown. Herein, we review the available literature regarding effects of diabetes pharmacotherapy, by drug class and/or by clinical indication, on the musculoskeletal health of persons with diabetes.

Lixisenatide enhances mitochondrial biogenesis and function through regulating the CREB/PGC-1α pathway

Mitochondrial dysregulation has been associated with vascular endothelial dysfunction and pathophysiological development of cardiovascular diseases. Lixisenatide is a drug approved by the US Food and Drug Administration for the treatment of type 2 diabetes (T2D). Little information regarding the effects of lixisenatide on mitochondrial function in endothelial cells has been reported before. In the current study, we found that treatment with lixisenatide significantly increased the expression of PGC-1α, a "molecular switch" of mitochondrial biogenesis in human umbilical vein endothelial cells (HUVECs). Lixisenatide treatment also promoted the expressions of NRF1 and TFAM, which are the target genes of PGC-1α and executors of mitochondrial biogenesis. Importantly, our results indicate that lixisenatide treatment promoted mitochondrial biogenesis by elevating the ratio of mitochondrial-to-nuclear DNA (mtDNA/nDNA), mitochondrial mass, cytochrome B expression, and citrate synthase activity in HUVECs. Correspondingly, we found that lixisenatide treatment led to a functional gain and improvement in mitochondria by increasing the mitochondrial respiration rate and ATP generation. Mechanistically, lixisenatide treatment induced the phosphorylation of CREB at Ser133. Blockage of CREB phosphorylation using its inhibitor H89 abolished the effects of lixisenatide on the activation of PGC-1α/NRF-1/TFAM as well as the increase in mtDNA/nDNA. These findings suggest that lixisenatide promoted mitochondrial biogenesis in endothelial cells through activating the PGC-1α signaling pathway, which is mediated by the transcriptional factor CREB.