Clinical Impact of ITCA 650, a Novel Drug-Device GLP-1 Receptor Agonist, in Uncontrolled Type 2 Diabetes and Very High Baseline HbA1c: The FREEDOM-1 HBL (High Baseline) Study

Double layer spherical nanoparticles with hyaluronic acid coating to enhance oral delivery of exenatide in T2DM rats

Soybean phospholipid was used as an amphiphilic material to form reverse micelles (RMs) in medium glycerol monolinoleate (Maisine) with Exenatide (EXT.) encapsulated in the polar core formed by the hydrophilic part of phospholipid. Cremopher RH40 and caprylocaproyl macrogol-8 glycerides EP/caprylocaproyl polyoxyl-8 glycerides NF (Labrasol) were added as surfactants to prepare reverse micelles-self emulsifying drug delivery system (RMs-SEDDS). On this basis, oil in water (O/W) emulsion was further prepared. By adding DOTAP, the surface of the emulsion was positively charged. Finally, hyaluronic acid wrapping in the outermost layer by electrostatic adsorption and reverse micelles-O/W-sodium hyaluronate (RMs-O/W-HA) nanoparticles containing Exenatide were prepared. RMs-SEDDS was spherical with an average particle size of 213.6 nm and RMs-O/W-HA was double-layered spherical nanoparticle with an average particle size of 309.2 nm. HA coating enhanced the adhesion of nanoparticles (NPs), and RMs-O/W-HA increased cellular uptake through CD44-mediated endocytosis. Pharmacodynamics results showed that RMs-SEDDS and RMs-O/W-HA could reduce blood glucose in type 2 diabetic rats, protect pancreatic β cells to a certain extent, and relieve insulin resistance and hyperlipemia complications with good safety.

Leveraging the therapeutic, biological, and self-assembling potential of peptides for the treatment of viral infections

Peptides and peptide-based materials have an increasing role in the treatment of viral infections through their use as active pharmaceutical ingredients, targeting moieties, excipients, carriers, or structural components in drug delivery systems. The discovery of peptide-based therapeutic compounds, coupled with the development of new stabilization and formulation strategies, has led to a resurgence of antiviral peptide therapeutics over the past two decades. The ability of peptides to bind cell receptors and to facilitate membrane penetration and subsequent intracellular trafficking enables their use in various antiviral systems for improved targeting efficiency and treatment efficacy. Importantly, the self-assembly of peptides into well-defined nanostructures provides a vast library of discrete constructs and supramolecular biomaterials for systemic and local delivery of antiviral agents. We review here the recent progress in exploiting the therapeutic, biological, and self-assembling potential of peptides, peptide conjugates, and their supramolecular assemblies in treating human viral infections, with an emphasis on the treatment strategies for Human Immunodeficiency Virus (HIV).

Translating results from the cardiovascular outcomes trials with glucagon-like peptide-1 receptor agonists into clinical practice: Recommendations from a Eastern and Southern Europe diabetes expert group

Glucagon-like peptide-1 (GLP-1) receptor agonists mimic the action of the endogenous GLP-1 incretin hormone, improving glycaemic control in type 2 diabetes mellitus (T2DM) by increasing insulin secretion and decreasing glucagon secretion in a glucose-dependent manner. However, as cardiovascular (CV) morbidity and mortality is common in patients with T2DM, several trials with the use of GLP-1 receptor agonists (RAs) have been performed focusing on endpoints related to cardiovascular disease rather than metabolic control of T2DM. Following the positive cardiovascular effects of liraglutide, dulaglutide and semaglutide observed in these trials, major changes in T2DM management guidelines have occurred. This document from a Eastern and Southern European Diabetes Expert Group discusses the results of GLP-1 RA CV outcomes trials, their impact on recent clinical guidelines for the management of T2DM, and some selected combination regimens utilising GLP-1 RAs. We also propose an algorithm for guiding GLP-1 RA-based treatment according to patients' characteristics, which can be easily applied in every day clinical practice.

Subcutaneous infusion of exenatide and cardiovascular outcomes in type 2 diabetes: a non-inferiority randomized controlled trial

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) injected periodically have been shown to not increase and, for some members of this class, decrease the risk of cardiovascular events. The cardiovascular safety of delivering a continuous subcutaneous infusion of the GLP-1RA exenatide (ITCA 650) is unknown. Here, we randomly assigned patients with type 2 diabetes with, or at risk for, atherosclerotic cardiovascular disease (ASCVD) to receive ITCA 650 or placebo to assess cardiovascular safety in a pre-approval trial ( NCT01455896 ). The primary outcome was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke or hospitalization for unstable angina. On the basis of 2008 guidance from the US Food and Drug Administration, a non-inferiority margin of 1.8 for the upper bound of the 95% confidence interval (CI) of the hazard ratio (HR) was used. We randomized 4,156 patients (2,075 assigned to receive ITCA 650 and 2,081 assigned to receive placebo) who were followed for a median of 16 months. The primary outcome occurred in 4.6% (95/2,075) of patients in the ITCA 650 group and 3.8% (79/2,081) of patients in the placebo group, meeting the pre-specified non-inferiority criterion (HR = 1.21, 95% CI, 0.90-1.63, P_{non-inferiority} = 0.004). Serious adverse events were similar between the two groups. Adverse events were more frequent in the ITCA 650 group (72%, 1,491/2,074) than in the placebo group (63.9%, 1,325/2,070), mainly due to an increase in gastrointestinal events and disorders while on ITCA 650. In patients with type 2 diabetes with, or at risk for, ASCVD, ITCA 650 was non-inferior to placebo. A larger and longer-duration cardiovascular outcomes trial is needed to define more precisely the cardiovascular effects of ITCA 650 in this population.

A 28-Day Toxicity Study of Tenofovir Alafenamide Hemifumarate by Subcutaneous Infusion in Rats and Dogs

The toxicity of tenofovir alafenamide (TAF) hemifumarate (HF) was evaluated when administered by continuous subcutaneous (s.c.) infusion via an external infusion pump for 28 days to rats and dogs. The toxicokinetics of TAF and two metabolites, tenofovir (TFV) and tenofovir diphosphate (TFV-DP) were also evaluated. After administration of TAF HF in rats and dogs, primary systemic findings supported an inflammatory response that was considered minimal to mild. Gross pathology and histopathologic evaluation of tissue surrounding the s.c. infusion site revealed signs of inflammation, including edema, mass formation, fibrosis, and mononuclear cell inflammation in groups receiving ≥300 μg/kg/day in rats and ≥25 μg/day in dogs. Although these changes were observed in animals receiving vehicle, the severity was greater in animals receiving TAF HF. Changes in the local tissue were considered a TAF HF-mediated exacerbation of an inflammatory response to the presence of the catheter. In rats, systemic and local findings were considered not adverse due to their low severity and reversibility; therefore, the "no observed adverse effect level" (NOAEL) was set at 1,000 μg/kg/day. Because none of the systemic findings were related to systemic exposure to TAF, the systemic NOAEL was set at 250 μg/kg/day in dogs. Due to the severity of the observations noted, a NOAEL for local toxicity could not be established. Although these results might allow for exploration of tolerability and pharmacokinetics of s.c. administered TAF HF in humans, data suggest a local reaction may develop in humans at doses below a clinically relevant dose. IMPORTANCE Human immunodeficiency virus (HIV) infection continues to be a serious global human health issue, with ∼38 million people living with HIV worldwide at the end of 2019. HIV preexposure prophylaxis (PrEP) has introduced the use of antiretroviral therapies as another helpful tool for slowing the spread of HIV worldwide. One possible solution to the problem of inconsistent access and poor adherence to HIV PrEP therapies is the development of subcutaneous (s.c.) depots or s.c. implantable devices that continuously administer protective levels of an HIV PrEP therapy for weeks, months, or even years at a time. We evaluate here the toxicity of tenofovir alafenamide, a potent inhibitor or HIV replication, after continuous s.c. infusion in rats and dogs for HIV PrEP.

Heterogeneity amongst GLP-1 RA cardiovascular outcome trials results: can definition of established cardiovascular disease be the missing link?

Atherosclerotic cardiovascular diseases are the leading cause of adverse outcomes in patients with type 2 diabetes, and all new anti-diabetic agents are mandated to undergo cardiovascular outcome trials (CVOTs). Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are incretin mimetics that reduce blood glucose levels with a low associated risk of hypoglycaemia. CVOTs with different GLP-1 RAs yielded different results in terms of major cardiovascular composite outcome (MACE), with some trials showing superiority in the treatment arm, whereas other simply displayed non-inferiority. More importantly, the significance of each component of MACE varied between drugs. This begs the question of whether these differences are due to dissimilarities between drugs or other factors, namely trial design, are at the root of these differences. We analyse the trial designs for all CVOTs with GLP-1 RAs and highlight important differences between them, namely in terms of definition of established cardiovascular disease, and discuss how these differences might explain the disparate results of the trials and preclude direct comparisons between them. We conclude that a fair comparison between GLP-1 RA CVOTs would involve post-hoc analysis re-grouping the patients into different cardiovascular risk categories based upon their baseline clinical parameters, in order to even out the criteria used to classify patients.

Development and Regulatory Challenges for Peptide Therapeutics

There has been an increased interest in and activity for the use of peptide therapeutics to treat a variety of human diseases. The number of peptide drugs entering clinical development and the market has increased significantly over the past decade despite inherent challenges of peptide therapeutic discovery, development, and patient-friendly delivery. Disparities in interpretation and application of existing regulatory guidances to innovative synthetic and conjugated peptide assets have resulted in challenges for both regulators and sponsors. The Symposium on Development and Regulatory Challenges for Peptide Therapeutics at the 40th Annual Meeting of the American College of Toxicology held in November of 2019 focused on the following specific topics: (1) peptide therapeutic progress and future directions, and approaches to discover, optimize, assess, and deliver combination peptide therapeutics for treatment of diseases; (2) toxicological considerations to advance peptide drug-device combination products for efficient development and optimal patient benefit and adherence; (3) industry and regulatory perspectives on the regulation of synthetic and conjugated peptide products, including exploration of regulatory classifications, interpretations, and application of the existing guidances International Council for Harmonisation (ICH) M3(R2) and ICH S6(R1) in determining nonclinical study recommendations; and (4) presentation of the 2016 Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee working group assessment of genotoxicity testing requirements. Perspectives were shared from industry and regulatory scientists working in the peptide therapeutics field followed by an open forum panel discussion to discuss questions drafted for the peptide therapeutics scientific community, which will be discussed in more detail.

Gut Peptide Agonism in the Treatment of Obesity and Diabetes

Obesity is a global healthcare challenge that gives rise to devastating diseases such as the metabolic syndrome, type-2 diabetes (T2D), and a variety of cardiovascular diseases. The escalating prevalence of obesity has led to an increased interest in pharmacological options to counteract excess weight gain. Gastrointestinal hormones such as glucagon, amylin, and glucagon-like peptide-1 (GLP-1) are well recognized for influencing food intake and satiety, but the therapeutic potential of these native peptides is overall limited by a short half-life and an often dose-dependent appearance of unwanted effects. Recent clinical success of chemically optimized GLP-1 mimetics with improved pharmacokinetics and sustained action has propelled pharmacological interest in using bioengineered gut hormones to treat obesity and diabetes. In this article, we summarize the basic biology and signaling mechanisms of selected gut peptides and discuss how they regulate systemic energy and glucose metabolism. Subsequently, we focus on the design and evaluation of unimolecular drugs that combine the beneficial effects of selected gut hormones into a single entity to optimize the beneficial impact on systems metabolism. © 2020 American Physiological Society. Compr Physiol 10:99-124, 2020.

Incretins in obesity and diabetes

Incretins are hormones secreted from enteroendocrine cells after nutrient intake that stimulate insulin secretion from β cells in a glucose-dependent manner. Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the only two known incretins. Dysregulation of incretin secretion and actions are noted in diseases such as obesity and diabetes. In this review, we first summarize our traditional understanding of the physiology of GIP and GLP-1, and our current knowledge of the relationships between GIP and GLP-1 and obesity and diabetes. Next, we present the results from major randomized controlled trials on the use of GLP-1 receptor agonists for managing type 2 diabetes, and emerging data on treating obesity and prediabetes. We conclude with a glimpse of the future with possible complex interactions between nutrients, gut microbiota, the endocannabinoid system, and enteroendocrine cells.

Molecular and Materials Engineering for Delivery of Peptide Drugs to Treat Type 2 Diabetes

Type 2 diabetes is exploding globally. Despite numerous treatment options, nearly half of type 2 diabetics are unsuccessful at properly managing the disease, primarily due to a lack of patient compliance, driven by adverse side effects as well as complicated and frequent dosing schedules. Improving the delivery of type 2 diabetes drugs has the potential to increase patient compliance and thus, greatly enhance health outcomes and quality of life. This review focuses on molecular and materials engineering strategies that have been implemented to improve the delivery of peptide drugs to treat type 2 diabetes. Peptide drugs benefit from high potency and specificity but suffer from instability and short half-lives that limit their utility as therapeutics and pose a significant delivery challenge. Several approaches have been developed to improve the availability and efficacy of antidiabetic peptides and proteins in vivo. These methods are reviewed herein and include devices, which sustain the release of peptides in long term, and molecular engineering strategies, which prolong circulation time and slow the release of therapeutic peptides. By optimizing the delivery of these peptides and proteins using these approaches, long-term glucose control can be achieved in type 2 diabetes patients.

Therapeutic medications against diabetes: What we have and what we expect

Diabetes has become one of the largest global health and economic burdens, with its increased prevalence and high complication ratio. Stable and satisfactory blood glucose control are vital to reduce diabetes-related complications. Therefore, continuous attempts have been made in antidiabetic drugs, treatment routes, and traditional Chinese medicine to achieve better disease control. New antidiabetic drugs and appropriate combinations of these drugs have increased diabetes control significantly. Besides, novel treatment routes including oral antidiabetic peptide delivery, nanocarrier delivery system, implantable drug delivery system are also pivotal for diabetes control, with its greater efficiency, increased bioavailability, decreased toxicity and reduced dosing frequency. Among these new routes, nanotechnology, artificial pancreas and islet cell implantation have shown great potential in diabetes therapy. Traditional Chinese medicine also offer new options for diabetes treatment. Our paper aim to overview these therapeutic methods for diabetes therapy. Proper combinations of these existing anti-diabetic medications and searching for novel routes are both necessary for better diabetes control.

Mitral cells and the glucagon-like peptide 1 receptor: The sweet smell of success?

The olfactory bulb (OB) is often affected at very early stages of neurodegenerative disorders, in the so-called "prodromal" phase. In Parkinson's disease (PD), olfactory disturbances appear years before motor symptoms arise. Additionally, pathological alpha-synuclein aggregates are found in olfactory regions before spreading to other areas of the brain. Being positioned at the frontier between the brain and a potentially hostile environment, could explain the particular vulnerability of the OB. Mitral cells (MCs), the principal projecting neurons of the olfactory system, are involved in the pathogenesis and in the prion-like progression of PD. They are affected by Lewy pathology and are thought to contribute to the axonal transport of misfolded alpha-synuclein to other regions of the brain. Here, we first describe the main markers reported to distinguish MCs from other olfactory neurons. We focus on the glucagon-like peptide 1 receptor (GLP-1R), a membrane protein specifically expressed in MCs. After summarizing OB pathology, we explore the idea of targeting specifically MCs with GLP-1 or its analogues. Exenatide has shown great promise as a neuroprotective and neurorestorative agent and has been used in a clinical trial for clinical PD. Since GLP-1R activation has the ability to mitigate many facets of prodromal PD pathology, we postulate that once a robust biomarker is in place that is capable of identifying individuals in the prodromal phase of PD, homing in on GLP-1R could assist in deferring, or eradicating to a significant degree, the clinical manifestation of this debilitating human disorder.

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.

The Clinical Impact of GLP-1 Receptor Agonists in Type 2 Diabetes: Focus on the Long-Acting Analogs

GLP-1 receptor agonists (GLP-1 RAs), introduced for clinical use in 2005, have excellent potency in reducing HbA_1c and mean glucose, improving fasting plasma glucose, inducing weight loss or protecting against the weight gain associated with insulin therapy, reducing appetite, and delaying gastric emptying. Two of these medications, liraglutide and semaglutide, appear to have cardioprotective effects as reflected in cardiovascular outcomes studies. The GLP-1 RAs are associated with gastrointestinal side effects that tend to diminish over time. They have very low risk of hypoglycemia unless used in conjunction with insulin or insulin secretagogues. Two coformulations of GLP-1 RAs together with long-acting basal insulin are available for daily use. The original GLP-1 RA, exenatide, requires twice-daily injections; two short-acting analogs are given once daily. Three currently available long-acting GLP-1 RAs are injected once weekly, providing greater convenience and potentially improving patient adherence. Semaglutide appears to be the most effective in terms of HbA_1c reduction and weight loss. GLP-1 RAs can be combined with all classes of antihyperglycemic agents except DPP-4 inhibitors. Current studies are exploring the use of an implantable osmotic pump for long-term administration of a rapid acting analog (exenatide), an oral preparation of semaglutide, benefits for management of obesity and nonalcoholic steatohepatitis, and mechanisms of cardioprotective effects.