Glucagon-like peptide-1 receptor agonists to improve cardiorenal outcomes: data from FLOW and beyond

PURPOSE OF REVIEW

Glucagon-like peptide-1 receptor agonists (GLP1RA), initially approved for glycemic control in type 2 diabetes mellitus (T2DM), have emerged as agents for weight loss, cardiovascular and kidney protection. This review summarizes the evidence supporting the benefits of these therapies on cardiorenal outcomes.

RECENT FINDINGS

Clinical trials have consistently demonstrated reductions in major adverse cardiovascular events with GLP1RA treatments. Recently, the FLOW trial revealed that semaglutide reduced the composite outcome of kidney failure, at least 50% decline in estimated glomerular filtration rate, kidney or cardiovascular mortality by 24% in patients with T2DM, thereby establishing GLP1RA as a pillar of therapy in this population. New evidence suggests favorable effects on kidney endpoints in nondiabetic individuals with overweight or obesity. Dedicated trials have also provided evidence for reduction in the risk for heart failure hospitalization and improvement in symptoms in individuals with heart failure with preserved ejection fraction. Subgroup analyses have suggested that GLP1RAs confer additive cardiorenal benefits irrespective of background medication use.

SUMMARY

There is increasing evidence that GLP1RA reduces the risk for cardiovascular events, chronic kidney disease progression, and heart failure hospitalizations. Further data on the effect of dual and triple GLP1-based therapies on cardiorenal outcomes is required.

Albumin-based delivery systems: Recent advances, challenges, and opportunities

Albumin and albumin-based biomaterials have been explored for various applications, including therapeutic delivery, as therapeutic agents, as components of tissue adhesives, and in tissue engineering applications. Albumin has been approved as a nanoparticle containing paclitaxel (Abraxane®), as an albumin-binding peptide (Victoza®), and as a glutaraldehyde-crosslinked tissue adhesive (BioGlue®). Albumin is also approved as a supportive therapy for various conditions, including hypoalbuminemia, sepsis, and acute respiratory distress syndrome (ARDS). However, no other new albumin-based systems in a hydrogel format have been used in the clinic. A review of publicly available clinical trials indicates that no new albumin drug delivery formats are currently in the clinical development pipeline. Although albumin has shown promise as a carrier of therapeutics for various diseases, including diabetes, cancers, and infectious diseases, its potential for treating blood-borne diseases such as HIV and leukemia has not been translated. This review offers a perspective on the use of albumin-based drug delivery systems for a broader range of disease applications, considering the protein properties and a review of the currently approved albumin-based technologies. This review supports ongoing efforts to advance biomedical research and clinical interventions through albumin-based delivery systems.

Optimized suction patch design for enhanced transbuccal macromolecular drug delivery

Peptides represent a rapidly expanding class of drugs with broad therapeutic potential. However, due to their large molecular weight and susceptibility to degradation in the gastrointestinal tract, most peptide drugs are administered via subcutaneous injections. Despite extensive research, a painless broad delivery platform for these drugs is still lacking. Recently, an octopus-inspired buccal patch has shown promise in addressing this challenge by leveraging a synergistic combination of mechanical stretching and permeation enhancers. In this study, the patch and the loaded formulation were optimized to improve ease of use, scalability, and efficacy. Through assessments of mechanical properties, finite element simulations, and ex vivo experiments, we evaluated the effects of patch design and material, as well as the drug matrix composition and the formulation preparation methods on the delivery performance. A patch with a > 9-fold larger effective surface area, produced via mold casting of medical-grade silicone (shore hardness 50) and loaded with a lyophilized drug matrix, emerged as the most promising system. In beagle dogs, 30-min application of this patch resulted in a 14.6 % bioavailability for teriparatide (4118 g mol-1), while bioavailability of semaglutide (4114 g mol-1) was 9.6 times higher than that of the commercial tablet. This work showcases how systematic optimization of this technology can improve and simplify the buccal administration of macromolecular drugs, facilitating the clinical translation of this non-invasive dosage form.

Real-world retrospective study in elderly patients aged 65 years and older with type 2 diabetes mellitus treated with daily oral semaglutide (SEMA-elderly)

AIM

This real-world, retrospective cohort study aimed to assess the efficacy, safety and tolerability of oral semaglutide-the first GLP-1 receptor agonist available in oral form-in patients aged 65 years and older with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline (V1) to six months (V3). Secondary endpoints included change in body weight, proportion of patients achieving HbA1c <7%, proportion of patients achieving both an HbA1c reduction of ≥1% and a body weight reduction of ≥5%. Exploratory endpoints were also assessed, including evaluations at three months (V2).

RESULTS

One hundred and one patients (mean age 74.7 ± 6.1 years) started oral semaglutide treatment. Mean HbA1c decreased significantly from V1 to V3 (change: -0.44%, p < 0.001), with reductions already evident at V2. The proportion of patients achieving an HbA1c ≤7% increased from 36.6% at V1 to 61.7% at V3. At V3, 9.6% of patients achieved an HbA1c reduction of ≥1% and a weight loss of ≥5%. Body weight decreased from a baseline mean of 76.8-73.7 kg at V3 (p < 0.001). Body mass index, waist circumference, total cholesterol, low-density lipoprotein cholesterol and systolic blood pressure decreased significantly from V1 to V3, with changes already evident at V2. Eleven patients (10.9%) reported adverse events. Seven patients (6.9%) discontinued treatment.

CONCLUSION

Oral semaglutide effectively improves glycaemic control and weight management in elderly patients with T2DM while improving lipid and cardiovascular parameters and proving to be safe and well tolerated.

Discovery of New Difluorocyclobutyl Derivatives as Effective Glucagon-Like Peptide-1 Receptor Agonists with Reduced hERG Inhibitory Activities

Danuglipron (PF-06882961), a small-molecule agonist of the glucagon-like peptide-1 receptor (GLP-1R) developed by Pfizer, has shown significant potential to reduce blood glucose levels and weight in patients with type 2 diabetes mellitus. However, it has moderate hERG inhibitory activities (IC50 = 4.3 μM), potentially conferring a risk for cardiac toxicity. Here, we report a new class of difluorocyclobutyl derivatives that can be used to reduce the potential hERG inhibition caused by the piperidine ring of danuglipron. After in vitro and in vivo screening, compound 73 was found to be the most potent GLP-1R agonist, with an EC50 of 0.048 nM. Furthermore, compound 73 showed preferable absorption and excellent β-arrestin pathway selectivity compared with danuglipron. In the glucose tolerance test, compound 73 effectively inhibited elevated blood glucose levels. These results indicate that compound 73 is a promising GLP-1R agonist.

Devices to overcome the buccal mucosal barrier to administer Therapeutic Peptides

Peptide therapeutics are important in healthcare owing to their high target specificity, therapeutic efficacy, and relatively low side effect profile. Injections of these agents have improved thetreatment of chronic diseases including autoimmune, metabolic disorders, and cancer. However, their administration via injections can prove a barrier to patient acceptability of treatments. While oral delivery of these molecules is preferable, oral peptide formulations are associated with limited bioavailability due to degradation in the intestine and low epithelial permeability. Buccal administration of peptides is a potential alternative to injections and oral formulations. Similar to the oral route, the buccal route can promote better patient adherence to dosing regimens, along with the added advantages of not requiring restriction on food or drink consumption before and after administration, as well as avoidance of the liver first-pass metabolism. However, like oral, effective buccal absorption of peptides is still challenging due to the high epithelial permeability barrier. We present a multidisciplinary approach to understanding the buccal physiological barrier to macromolecule permeation and discuss how engineered devices may overcome it. Selected examples of buccal devices can facilitate fast and efficient macromolecule absorption through multiple mechanisms including physical disruption of epithelia, convection-based mass transfer, and a combination of physicochemical strategies. Importantly, minimally invasive devices can be self-applied and are associated with the maintenance of the barrier after exposure. We analysed the critical attributes that are required forthe clinical translation of buccal peptide administration devices. These include performance-driven device development, manufacturing features, patient acceptability, and commercial viability.

Advances in incretin therapies for targeting cardiovascular disease in diabetes

The global prevalence of obesity is skyrocketing at an alarming rate, with recent data estimating that one-in-eight people are now living with the disease. Obesity is a chronic metabolic disorder that shares underlying pathophysiology with other metabolically-linked diseases such as type 2 diabetes mellitus, cardiovascular disease and diabetic cardiomyopathy. There is a distinct correlation between type 2 diabetes status and the likelihood of heart failure. Of note, there is an apparent sexual dimorphism, with women disproportionately affected with respect to the degree of severity of the cardiac phenotype of diabetic cardiomyopathy that results from diabetes. The current pharmacotherapies available for the attenuation of hyperglycaemia in type 2 diabetes are not always effective, and have varying degrees of efficacy in the setting of heart failure. Insulin can worsen heart failure prognosis whereas metformin, sodium-glucose cotransporter 2 inhibitors (SGLT2i) and more recently, glucagon-like peptide-1 receptor agonists (GLP-1RAs), have demonstrated cardioprotection with their administration. This review will highlight the advancement of incretin therapies for individuals with diabetes and heart failure and explore newly-reported evidence of the clinical usefulness of GLP-1R agonists in this distinct phenotype of heart failure.

Peptide-Bound Aflibercept Eye Drops for Treatment of Neovascular Age-Related Macular Degeneration in Nonhuman Primates

The advent of biomacromolecules antagonizing vascular endothelial growth factor (VEGF) has revolutionized the treatment of neovascular age-related macular degeneration (nAMD). However, frequent intravitreal injections of these biomacromolecules impose an enormous burden on patients and create a massive workload for healthcare providers. This causes patients to abandon therapy, ultimately leading to progressive and irreversible vision loss. In order to address this unmet clinical need, a noninvasive treatment for nAMD is developed. An optimized cell-penetrating peptide derivative, bxyPenetratin (bxyWP), is used to non-covalently complex with the anti-VEGF protein aflibercept (AFL) via reversible hydrophobic interaction. The interaction is crucial for AFL delivery, neither impairing the affinity of AFL to pathological VEGF, nor being interfered by endogenous proteins in tear fluids. AFL/bxyWP eye drops exhibit prolonged retention on the eye and excellent absorption into the posterior ocular segment following topical administration, with significant drug distribution to the retina and choroid. In a laser-induced choroidal neovascularization model on cynomolgus monkeys, AFL/bxyWP eye drops efficiently reduce lesion size and leakage comparable to conventional intravitreal injection of AFL. These results suggest that AFL/bxyWP eye drops are feasible self-administered treatment for neovascular retinal diseases and potentially become a substitute for intravitreal injections.

From lead to market: chemical approaches to transform peptides into therapeutics

Peptides are a powerful drug modality with potential to access difficult targets. This recognition underlies their growth in the global pharmaceutical market, with peptides representing ~8% of drugs approved by the FDA over the past decade. Currently, the peptide therapeutic landscape is evolving, with high-throughput display technologies driving the identification of peptide leads with enhanced diversity. Yet, chemical modifications remain essential for improving the 'drug-like' properties of peptides and ultimately translating leads to market. In this review, we explore two recent therapeutic candidates (semaglutide, a peptide hormone analogue, and MK-0616, an mRNA display-derived candidate) as case studies that highlight general approaches to improving pharmacokinetics (PK) and potency. We also emphasize the critical link between advances in medicinal chemistry and the optimisation of highly efficacious peptide therapeutics.

pH Controlled Transient Cyclization of Peptides for Increased Stability towards Oral Delivery

Peptides are highly efficient for treatment of many diseases, especially in oncology and diabetes. Oral delivery of peptides is desirable, but is challenged by low bioavailability and new chemical methods to enable oral delivery are needed. Here, we developed pH responsive linearization as a strategy for transient protection of peptides to extend their half-life in model systems. Peptides were cyclized to increase their stability at the low pH in the stomach, while they linearize at neutral pH to form the active peptide. We developed ester based responsive linkers with a protonable amine for O-to-N acyl shift, which allowed linearization strategies based on pyroglutamoyl (pGlu) or diketopiperazine (DKP) formation. After coupling of the linker, peptides were cyclized by CuAAC. We studied the stability against simulated gastric fluid (SGF) at different pH and the ability of cyclic peptides to linearize. This led to PYY3-36 analogues with pH responsive linearization for increased stability.

GLP-1 receptor agonists, are we witnessing the emergence of a paradigm shift for neuro-cardio-metabolic disorders?

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as groundbreaking therapeutic agents in managing a spectrum of metabolic disorders, demonstrating remarkable efficacy across multiple organ systems and disease states. These compounds are not only well-established in the treatment of type 2 diabetes (T2D) and obesity-conditions for which they have received widespread approval-but also exhibit promising potential in addressing cardiovascular disease (CVD) and Metabolic dysfunction-associated steatotic liver disease (MASLD). Recent investigations have begun to illuminate the utility of GLP-1RAs in the management of type 1 diabetes (T1D), as well as neurodegenerative disorders such as Alzheimer's and Parkinson's disease and various behavioral disorders. A plethora of clinical trials have consistently validated the capacity of GLP-1RAs to improve glycemic control, promote weight loss, and mitigate cardiovascular risk factors in individuals with T2D and obesity. While their application in T1D remains limited due to safety concerns-particularly regarding the risks of hypoglycemia and hyperglycemic ketoacidosis-emerging data suggest that GLP-1RAs may offer hepatoprotective benefits, potentially reducing liver fat content and decelerating the progression of MASLD. The neuroprotective attributes of GLP-1 RAs have garnered significant interest, with research indicating their potential to alleviate cognitive decline associated with neurodegenerative diseases. Furthermore, preliminary findings highlight the role of GLP-1 RAs in addressing behavioral disorders, emphasizing their extensive therapeutic promise. This comprehensive review synthesizes the current evidence supporting the diverse therapeutic applications of GLP-1RAs, positioning them as "magic drug" therapies for metabolic and neurological disorders. As ongoing research continues to explore innovative applications and combinations of GLP-1RAs, the landscape of disease management in metabolic and neurological contexts is poised for transformative advancements. This review will also critically assess safety considerations and underscore the need for personalized treatment strategies to optimize patient outcomes in these complex and often comorbid conditions.

GLP-1-based therapies for type 2 diabetes: from single, dual and triple agonists to endogenous GLP-1 production and L-cell differentiation

Glucagon-like peptide-1 (GLP-1) is an incretin peptide hormone mainly secreted by enteroendocrine intestinal L-cells. GLP-1 is also secreted by α-cells of the pancreas and the central nervous system (CNS). GLP-1 secretion is stimulated by nutrient intake and exerts its effects on glucose homeostasis by stimulating insulin secretion, gastric emptying confiding the food intake, and β-cell proliferation. The insulinotropic effects of GLP-1, and the reduction of its effects in type 2 diabetes mellitus (T2DM), have made GLP-1 an attractive option for the treatment of T2DM. Furthermore, GLP-1-based medications such as GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, have been shown to improve diabetes control in preclinical and clinical trials with human subjects. Importantly, increasing the endogenous production of GLP-1 by different mechanisms or by increasing the number of intestinal L-cells that tend to produce this hormone may be another effective therapeutic approach to managing T2DM. Herein, we briefly describe therapeutic agents/compounds that enhance GLP-1 function. Then, we will discuss the approaches that can increase the endogenous production of GLP-1 through various stimuli. Finally, we introduce the potential of L-cell differentiation as an attractive future therapeutic approach to increase GLP-1 production as an attractive therapeutic alternative for T2DM.

Discovery of Selenium-Containing Derivatives as Potent and Orally Bioavailable GLP-1R Agonists

Glucagon-like peptide-1 receptor (GLP-1R) is a well-established target for the treatment of type 2 diabetes mellitus (T2DM) and obesity. The development of orally bioavailable and long-acting small-molecule GLP-1R agonists is a pursuit in both academia and industry. Herein, new selenium (Se)-containing compounds were designed using a Se-oxygen bioisostere strategy on the danuglipron scaffold. Among these, compound 21 was orally bioavailable and exhibited full agonistic efficacy in promoting cyclic adenosine monophosphate (cAMP) accumulation. In hGLP-1R knock-in mice, 21 effectively reduced blood glucose levels and food intake, with the duration of action slightly extended compared to that of danuglipron. Importantly, no significant adverse effects were observed in mice treated with 21 during the subacute toxicity studies. This study delineates the potential of Se-containing compounds as orally bioavailable GLP-1R agonists, with compound 21 emerging as a promising candidate for T2DM and obesity treatment.

Advances in Oral Biomacromolecule Therapies for Metabolic Diseases

Metabolic diseases like obesity and diabetes are on the rise, and therapies with biomacromolecules (such as proteins, peptides, antibodies, and oligonucleotides) play a crucial role in their treatment. However, these drugs are traditionally injected. For patients with chronic diseases (e.g., metabolic diseases), long-term injections are accompanied by inconvenience and low compliance. Oral administration is preferred, but the delivery of biomacromolecules is challenging due to gastrointestinal barriers. In this article, we introduce the available biomacromolecule drugs for the treatment of metabolic diseases. The gastrointestinal barriers to oral drug delivery and strategies to overcome these barriers are also explored. We then discuss strategies for alleviating metabolic defects, including glucose metabolism, lipid metabolism, and energy metabolism, with oral biomacromolecules such as insulin, glucagon-like peptide-1 receptor agonists, proprotein convertase subtilisin/kexin type 9 inhibitors, fibroblast growth factor 21 analogues, and peptide YY analogues.

Combining SNAC and C10 in oral tablet formulations for gastric peptide delivery: A preclinical and clinical study

Current oral formulations of macromolecules including peptides typically rely on single permeation enhancer (PE) to promote absorption and thus bioavailability. In this work, we combined two PEs, namely sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) and sodium caprate (C10), in one tablet formulation to potentially gain a synergistic effect for enhanced gastric absorption of a GLP-1 analogue and a PCSK9 inhibitor. Permeability tests on a gastric organoids-based cell model showed that the combination of SNAC and C10 can significantly improve peptide permeability compared to either SNAC or C10 alone. Tablet formulations were then designed, adjusting the total PE amount, relative ratio between SNAC and C10, and the peptide dose. To facilitate drug and PE release, a diluent was added. Upon oral administration in beagle dogs, the lead formulations made of SNAC/C10/diluent demonstrated higher bioavailability than either SNAC, SNAC/diluent and C10/diluent formulations for both peptides. Finally, the SNAC/C10/diluent formulation with PCSK9 inhibitor was tested in human, where it displayed similar bioavailability to the SNAC/diluent reference, thereby suggesting a low translatability between pre-clinical and clinical data when C10 was involved. This may be attributed to the difference in physiology, gastric pH environment as well as C10 concentration and colloidal form in the gastric lumen between dogs and humans. Hence, additional studies are needed for a better understanding of the clinical translation of C10-based peptide formulations.

An oral liraglutide nanomicelle formulation conferring reduced insulin-resistance and long-term hypoglycemic and lipid metabolic benefits

Type 2 diabetes is a chronic disease characterized by insulin resistance and often worsened by obesity. Effective management involves the use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to assist with glycemic control and weight management. However, these drugs must be administered subcutaneously due to their low oral bioavailability. We developed an oral liraglutide (LRG) formulation by electrostatic complexation of GLP-1 RA with bile acid derivatives and nanomicelle (NM) formation, with non-ionic surfactant n-dodecyl-β-d-maltoside (DDM). The optimized formulation, LDD[1:2:4]-NM, had a mean particle size of 75.9 ± 5.60 nm and a permeability 1347 % higher than that of unformulated LRG when tested in Caco-2/HT29-MTX-E12 cell monolayers. In rats, oral bioavailability was 4.63-fold higher than that of unformulated LRG (1.11 ± 0.20 % vs. 5.14 ± 0.63 %). The absorption mechanism included clathrin-mediated endocytosis, macropinocytosis, and an ASBT-mediated pathway. A 12-week oral treatment consisting of a daily dose of 20 mg LDD[1:2:4]-NM/kg significantly reduced glycohemoglobin levels, a marker of diabetic control, and the HOMA-IR index, a marker of insulin resistance. The weight of epididymal and inguinal white adipose tissue and brown adipose tissue (BAT) was also reduced. Moreover, LDD[1:2:4]-NM had a greater impact on BAT activation, pro-inflammatory gene expression, and lipid metabolism than subcutaneous LRG. This study showed that an oral NM formulation can efficiently deliver LRG. Long-term treatment led to improved hyperglycemic effects, insulin resistance, and modulated lipid metabolism. LDD[1:2:4]-NM is thus a promising oral therapeutic option for the management of type 2 diabetes, potentially transforming treatment paradigms based on the availability of a more convenient administration route.

Non-clinical and first-in-human characterization of ECC5004/AZD5004, a novel once-daily, oral small-molecule GLP-1 receptor agonist

AIMS

GLP-1 receptor agonists (GLP-1 RAs) are proven therapies for type 2 diabetes mellitus (T2DM) and overweight or obesity. We performed non-clinical and first-in-human (FIH) evaluation of ECC5004/AZD5004, an oral small-molecule GLP-1 RA.

MATERIALS AND METHODS

ECC5004 was profiled in cell lines overexpressing human GLP-1R, in glucose-stimulated insulin secretion (GSIS) assays in a human β-cell line and non-human primates (NHPs). To evaluate safety, ECC5004 was orally administered to NHPs for 9 months and a phase I, double-blind, placebo-controlled FIH study was conducted. This study evaluated single doses of ECC5004 (1-300 mg) in healthy volunteers, and multiple daily doses (5, 10, 30 and 50 mg) in patients with T2DM for 28 days.

RESULTS

ECC5004 bound to the hGLP-1R (IC50 = 2.4 nM) augmented cAMP signalling without β-arrestin-2 recruitment or receptor internalization. ECC5004 potentiated GSIS in both EndoC-βH5 cells (EC50 = 5.9 nM) and in vivo in NHPs (EC50 = 0.022 nM). Dose-dependent body weight changes compared to control were seen in the 9-month NHP toxicity study. In the first-in-human study, ECC5004 was well tolerated with no serious adverse events. Dose-dependent reductions in glucose and body weight were observed with a dose-proportional exposure at doses ≥25 mg.

CONCLUSION

ECC5004 engaged the GLP-1R across the therapeutic dose range tested and had a safety and tolerability profile consistent with other GLP-1 RAs, along with a pharmacokinetic profile compatible with once-daily oral dosing. These data support continued development of ECC5004 as a potential therapy for T2DM and overweight or obesity.

CLINICAL TRIAL REGISTRATION

NCT05654831.

The Effects of Oral Semaglutide on Hepatic Fibrosis in Subjects with Type 2 Diabetes in Real-World Clinical Practice: A Post Hoc Analysis of the Sapporo-Oral SEMA Study

BACKGROUND/OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an important common comorbidity in subjects with type 2 diabetes, and liver fibrosis is a factor directly related to its prognosis. Glucagon-like peptide-1 receptor agonists are useful treatment options for MASLD; however, the efficacy of oral semaglutide in treating liver steatosis/fibrosis has not been fully elucidated.

METHODS

A secondary analysis of a multicenter, retrospective, observational study investigating the efficacy and safety of oral semaglutide in Japanese subjects with type 2 diabetes in a real-world clinical setting (the Sapporo-Oral SEMA study) was conducted. Subjects in the original cohort were divided into groups as follows: subjects with suspected MASLD (alanine aminotransferase > 30 U/L) were placed in an overall group; a subpopulation from an overall group at high risk for hepatic fibrosis (fibrosis-4 (FIB-4) index ≥ 1.3 or platelet count < 200,000/µL) was placed in a high-risk group; and the remaining subjects were placed in a low-risk group. Changes in the hepatic steatosis index and FIB-4 index after oral semaglutide induction were explored using a paired t-test or the Wilcoxon signed-rank test.

RESULTS

Overall, 169 subjects (including 131 that switched from other medications) were analyzed, and 67 and 102 subjects were selected for the high-risk and low-risk groups, respectively. Oral semaglutide significantly improved the hepatic steatosis index (from 46.1 to 44.6, p < 0.001) and FIB-4 index (from 1.04 to 0.96, p < 0.001) as well as several metabolic parameters in all cohorts. The efficacy of semaglutide in treating liver fibrosis was confirmed by the addition of, and switching from, existing agent groups. Furthermore, improvement in the FIB-4 index was significantly negatively correlated with the baseline FIB-4 index.

CONCLUSIONS

The induction of oral semaglutide might be a useful treatment option for subjects with type 2 diabetes at high risk for liver fibrosis, even when switching from conventional medications for diabetes.

Salcaprozate-based ionic liquids for GLP-1 gastric delivery: A mechanistic understanding of in vivo performance

Oral delivery of peptides requires formulations with high concentrations of permeation enhancer (PE) to promote absorption, and often necessitates fasting time between dosing and food ingestion. Improved formulations promoting a more rapid absorption would increase convenience of use but requires a faster onset of action. We have developed a salcaprozate-based ionic liquid (IL) formulation, namely choline salcaprozate (CHONAC), for oral delivery of a glucagon-like peptide-1 (GLP-1) analogue via gastric absorption. In vitro studies confirmed the higher amount of PE accommodated in the same volume of dosage form as well as faster release of the active pharmaceutical ingredient (API) and PE compared to the tablet reference. Storage stability of the CHONAC formulation was demonstrated for up to 3 weeks at 4 °C. The peptide absorption efficacy of the IL formulation was first evaluated in vivo in rats and anesthetized dogs, showing a faster absorption compared to the reference formulations. In awake dogs, while the CHONAC formulation still enabled earlier API absorption, its overall exposure was inferior to the tablet reference. This was attributed mostly to the gastric physiology, causing formulation dilution in the presence of additional fluid as well as fast transit of liquids into the duodenum, where peptides liable to proteolytic degradation such as the one used in this study showed a negligible absorption, potentially also due to a lower permeation-enhancing capability of CHONAC in the duodenal region. Exploring these issues, an in vivo study in anesthetized dogs involving repeated dosing of a liquid salcaprozate-based formulation in the stomach revealed the potential to sustain peptide absorption throughout the dosing period with a constant absorption rate. In conclusion, combining the advantages of high PE amounts and fast onset of action provided by the IL formulation, and ensuring a prolonged interaction of peptide and PE at a relevant concentration with the stomach epithelium, are necessary to enhance oral peptide bioavailability via gastric delivery.

Bioinspired orthogonal-shaped protein-biometal nanocrystals enable oral protein absorption

With the growing number of marketed biological drugs, the development of technological strategies for their oral systemic absorption, becomes increasingly important. The harsh gastrointestinal environment and low permeability of the intestinal epithelium, represent a huge challenge for their systemic delivery. Herein, bioinspired in the physiological insulin-Zn interaction, the design of orthogonal-shaped protein-biometal hybrid nanocrystals, further enveloped by a bilayer of functional biomaterials, is reported. The nanocrystals exhibited a size of 80 nm, a neutral surface charge and a high insulin loading. In vitro studies showed the capacity of the nanocomplexes to control the release of the associated insulin, while preserving its stability. In vivo evaluation showed sustained blood glucose reductions in both healthy and diabetic rats (up to 40 % and 80 %, respectively), while chronic immunotoxicity studies in mice indicated no toxicity effect. Preliminary efficacy studies in healthy awake pigs following oral capsule administration showed over 20 % absolute bioavailability.

Molecular Investigation of SNAC as an Oral Peptide Permeation Enhancer in Lipid Membranes via Solid-State NMR

Oral peptide therapeutics are increasingly favored in the pharmaceutical industry for their ease of use and better patient adherence. However, they face challenges with poor oral bioavailability due to their high molecular weight and surface polarity. Permeation enhancers (PEs) like salcaprozate sodium (SNAC) have shown promise in clinical trials, achieving about 1% bioavailability. One proposed mechanism for enhancing permeation is membrane perturbation or fluidization, though direct experimental proof and quantitative analysis of these effects are still needed. This study employs solid-state NMR (ssNMR) to investigate how SNAC interacts with hydrated DMPC liposomes, measuring enhancements in membrane fluidity across interfacial and transmembrane regions. The methodology involves analyzing phosphate lipid headgroups and acyl chains using static 31P chemical shift anisotropy and 2H quadrupolar coupling measurements alongside 1H and 13C magic angle spinning NMR for motional averaging of 1H-1H and 1H-13C dipolar couplings. Our findings indicate an overall increase in the uniaxial motion of phospholipids with SNAC in a PE concentration-dependent manner. It boosts lipid headgroup dynamics and enhancement plateaus at 25% between 24 and 72 mM concentrations. SNAC effectively enhances the fluidity of the hydrophobic center by 43% at 72 mM PE concentration, more significantly than the interfacial region. It is worth noting that the extent of liposome dissolution and conversion to micelles increases as SNAC concentration rises. Including a model peptide drug, octreotide, introduces a competitive equilibrium in this complex PE-lipid-peptide system, further influencing membrane dynamics for peptide permeation. Interestingly, the membrane enhancement does not show the expected plateau, and a less significant lipid mobility increase is observed in the presence of octreotide, suggesting a less substantial impact compared to peptide-free systems, which is likely due to peptide-PE interactions that consume monomeric SNAC, reducing its interaction with the lipid membrane. This study provides the first quantitative and site-specific ssNMR measurements of membrane mobility influenced by one representative PE as a snapshot of PE lipid interaction in a liposome model, demonstrating how peptide drugs modulate competitive equilibria and PE-induced lipid dynamics.

Advances in the transport of oral nanoparticles in gastrointestinal tract

Biological barriers in the gastrointestinal tract (GIT) prevent oral absorption of insoluble drugs. Recently, significant progress has been made in the development of various nanoparticles (NPs) designed to enhance the efficacy of oral drugs. However, the mechanism underlying the intracellular transport of NPs remains unclear, and there are still limitations to improving the oral bioavailability of drugs. This article reviews the challenges faced in the absorption of oral NPs, proposes strategies to overcome these barriers, and discusses the future prospects.

Changes in food preferences after oral semaglutide administration in Japanese patients with type 2 diabetes: KAMOGAWA-DM cohort

BACKGROUND

This study aimed to investigate the effects of oral semaglutide on the changes in food preference of Japanese patients with type 2 diabetes.

METHODS

This retrospective multicenter study included 75 patients with type 2 diabetes who received oral semaglutide. The primary outcome was the change in the score of brief-type self-administered diet history questionnaire (BDHQ) score 3 months after the initiation of oral semaglutide treatment. The secondary outcome was the change in the Control of Eating Questionnaire (CoEQ), HbA1c, and body mass index (BMI) after 3 months.

RESULTS

The median age, BMI, and HbA1c of the 23 participants were 64.0 years, 26.9 kg/m2, and 7.6% (59 mmol/mol). The BDHQ results showed total energy was significantly reduced. Among the individual nutrients, carbohydrates most decreased. The CoEQ results particularly showed declines in cravings for something sweet, chocolate or chocolate flavored foods, and starchy foods, satisfaction at meals, frequency and intensity of food craving, difficulty of resisting the craving for food, and frequency of eating in response to cravings for food were significantly lower after 3 months. The mean HbA1c and BMI significantly decreased.

CONCLUSIONS

In Japanese patients with type 2 diabetes, oral semaglutide treatment decreased total energy intake and changed food preferences.

Advanced microbiome therapeutics as a novel modality for oral delivery of peptides to manage metabolic diseases

The rising prevalence of metabolic diseases calls for innovative treatments. Peptide-based drugs have transformed the management of conditions such as obesity and type 2 diabetes. Yet, challenges persist in oral delivery of these peptides. This review explores the potential of 'advanced microbiome therapeutics' (AMTs), which involve engineered microbes for delivery of peptides in situ, thereby enhancing their bioavailability. Preclinical work on AMTs has shown promise in treating animal models of metabolic diseases, including obesity, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease. Outstanding challenges toward realizing the potential of AMTs involve improving peptide expression, ensuring predictable colonization control, enhancing stability, and managing safety and biocontainment concerns. Still, AMTs have potential for revolutionizing the treatment of metabolic diseases, potentially offering dynamic and personalized novel therapeutic approaches.

Neo-Glycolipid Oximes as Intestinal Permeation Enhancers for Peptide Hormone PYY3-36

Herein, we describe the design and synthesis of 16 neo-glycolipids that are potential permeation enhancers for oral drug delivery of peptide therapeutics. These amphiphilic neo-glycolipids are composed of fatty acids and various carbohydrates (d-glucose, lactose, cellobiose, maltose) via an oxime linker. The ability of the synthesized neo-glycolipids to enhance permeation of fluorescein-labelled dextran (4 kDa) or 3H-mannitol across intestinal epithelium was investigated in vitro using monolayers of human epithelial Caco-2 cells. Their effects were compared with (pre-)clinically known enhancers as reference compounds; sodium salts of octanoic, decanoic, and dodecanoic acid, and sodium salcaprozate (SNAC). Most neo-glycolipids increased the permeation of the model compounds, proving that neo-glycolipids, which possess vastly different properties from the reference compounds, e. g., in terms of clogD and polar surface area, are effective permeation enhancers. The neo-glycolipid based on decanoic acid and glucose was more potent than related compounds based on disaccharides. Significant differences in solubility and cellular compatibility were found for neo-glyolipids based on different carbohydrates. Finally, neo-glycolipids were evaluated as permeation enhancers for the peptide hormone PYY3-36. Glucose- and maltose-derived neo-glycolipids based on decanoic and dodecanoic acid showed promising enhancements in PYY3-36 permeation in vitro while maintaining good cellular compatibility, relevant for oral delivery of obesity treatments.

Cephalopod-inspired jetting devices for gastrointestinal drug delivery

Needle-based injections currently enable the administration of a wide range of biomacromolecule therapies across the body, including the gastrointestinal tract1-3, through recent developments in ingestible robotic devices4-7. However, needles generally require training, sharps management and disposal, and pose challenges for autonomous ingestible systems. Here, inspired by the jetting systems of cephalopods, we have developed and evaluated microjet delivery systems that can deliver jets in axial and radial directions into tissue, making them suitable for tubular and globular segments of the gastrointestinal tract. Furthermore, they are implemented in both tethered and ingestible formats, facilitating endoscopic applications or patient self-dosing. Our study identified suitable pressure and nozzle dimensions for different segments of the gastrointestinal tract and applied microjets in a variety of devices that support delivery across the various anatomic segments of the gastrointestinal tract. We characterized the ability of these systems to administer macromolecules, including insulin, a glucagon-like peptide-1 (GLP1) analogue and a small interfering RNA (siRNA) in large animal models, achieving exposure levels similar to those achieved with subcutaneous delivery. This research provides key insights into jetting design parameters for gastrointestinal administration, substantially broadening the possibilities for future endoscopic and ingestible drug delivery devices.

Adherence and treatment discontinuation of oral semaglutide and once-weekly semaglutide injection at 12 month follow-up: Japanese real-world data

Adherence and treatment continuation rates of the glucagon-like peptide-1 receptor agonist (GLP-1RA) semaglutide for both oral (O-SEMA) and subcutaneous injection (SEMA-SC) remain unknown in real-world clinical practice. This retrospective observational study compared the 12 month adherence and treatment discontinuation of O-SEMA and once-weekly SEMA-SC in patients with type 2 diabetes using a real-world claims database. SEMA-SC initiators were 1:1 propensity score-matched to O-SEMA initiators. Non-adherence was defined as <0.8 of the proportion of days covered. SEMA-SC had a significantly higher odds ratio (OR) for non-adherence than O-SEMA (OR: 1.39). The hazard ratio for treatment discontinuation, using O-SEMA as the reference, was 1.45 for SEMA-SC, although the discontinuation rate of O-SEMA was higher during the early stage. O-SEMA initiators showed significantly higher adherence and greater persistence in therapy than SEMA-SC initiators at 12 months, which could lead to earlier initiation of GLP-1RA treatment.

Development of 3D-Printed Two-Compartment Capsular Devices for Pulsatile Release of Peptide and Permeation Enhancer

OBJECTIVE

The oral absorption of a peptide is driven by a high local concentration of a permeation enhancer (PE) in the gastrointestinal tract. We hypothesized that a controlled release of both PE and peptide from a solid formulation, capable of maintaining an effective co-localized concentration of PE and peptide could enhance oral peptide absorption. In this study, we aimed to develop a 3D-printed two-compartment capsular device with controlled pulsatile release of peptide and sodium caprate (C10).

METHODS

3D-printed two-compartment capsular device was fabricated using a fused deposition modeling method. This device was then filled with LY peptide and C10. The release profile was modulated by changing the thickness and polymer type of the capsular device. USP apparatus II dissolution test was used to evaluate the impacts of device thickness and polymer selection on release profile in vitro. An optimal device was then enteric coated with HPMCAS.

RESULTS

A strong linear relationship between the thickness of capsular devices and the delay in the release onset time was observed. An increase in the device thickness or the use of PLA decreased the release rate. The capsular device with compartment 1, compartment 2 and fence thickness of 0.4; 0.95 and 0.5 mm, respectively, and the use of PVA achieved desired pulsatile release profiles of both peptide and C10. Furthermore, enteric-coated capsular devices with HPMCAS had similar pulsatile release profiles compared to non-enteric coated devices.

CONCLUSION

These findings suggest potential application of 3D-printing techniques in the formulation development for complex modified drug release products.

Therapeutic peptides in the treatment of digestive inflammation: Current advances and future prospects

Digestive inflammation is a widespread global issue that significantly impacts quality of life. Recent advances have highlighted the unique potential of therapeutic peptides for treating this condition, owing to their specific bioactivity and high specificity. By specifically targeting key proteins involved in the pathological process and modulating biomolecular functions, therapeutic peptides offer a novel and promising approach to managing digestive inflammation. This review explores the development history, pharmacological characteristics, clinical applications, and regulatory mechanisms of therapeutic peptides in treating digestive inflammation. Additionally, the review addresses pharmacokinetics and quality control methods of therapeutic peptides, focusing on challenges such as low bioavailability, poor stability, and difficulties in delivery. The role of modern biotechnologies and nanotechnologies in overcoming these challenges is also examined. Finally, future directions for therapeutic peptides and their potential impact on clinical applications are discussed, with emphasis placed on their significant role in advancing medical and therapeutic practices.

Peptide GLP-1 receptor agonists: From injection to oral delivery strategies

Peptide glucagon-like peptide-1 receptor agonists (GLP-1RAs) are effective drugs for treating type 2 diabetes (T2DM) and have been proven to benefit the heart and kidney. Apart from oral semaglutide, which does not require injection, other peptide GLP-1RAs need to be subcutaneously administered. However, oral semaglutide also faces significant challenges, such as low bioavailability and frequent gastrointestinal discomfort. Thus, it is imperative that advanced oral strategies for peptide GLP-1RAs need to be explored. This review mainly compares the current advantages and disadvantages of various oral delivery strategies for peptide GLP-1RAs in the developmental stage and discusses the latest research progress of peptide GLP-1RAs, providing a useful guide for the development of new oral peptide GLP-1RA drugs.

Intestinal Lymphatic Biology, Drug Delivery, and Therapeutics: Current Status and Future Directions

Historically, the intestinal lymphatics were considered passive conduits for fluids, immune cells, dietary lipids, lipid soluble vitamins, and lipophilic drugs. Studies of intestinal lymphatic drug delivery in the late 20th century focused primarily on the drugs' physicochemical properties, especially high lipophilicity, that resulted in intestinal lymphatic transport. More recent discoveries have changed our traditional view by demonstrating that the lymphatics are active, plastic, and tissue-specific players in a range of biological and pathological processes, including within the intestine. These findings have, in turn, inspired exploration of lymph-specific therapies for a range of diseases, as well as the development of more sophisticated strategies to actively deliver drugs or vaccines to the intestinal lymph, including a range of nanotechnologies, lipid prodrugs, and lipid-conjugated materials that "hitchhike" onto lymphatic transport pathways. With the increasing development of novel therapeutics such as biologics, there has been interest in whether these therapeutics are absorbed and transported through intestinal lymph after oral administration. Here we review the current state of understanding of the anatomy and physiology of the gastrointestinal lymphatic system in health and disease, with a focus on aspects relevant to drug delivery. We summarize the current state-of-the-art approaches to deliver drugs and quantify their uptake into the intestinal lymphatic system. Finally, and excitingly, we discuss recent examples of significant pharmacokinetic and therapeutic benefits achieved via intestinal lymphatic drug delivery. We also propose approaches to advance the development and clinical application of intestinal lymphatic delivery strategies in the future. SIGNIFICANCE STATEMENT: This comprehensive review details the understanding of the anatomy and physiology of the intestinal lymphatic system in health and disease, with a focus on aspects relevant to drug delivery. It highlights current state-of-the-art approaches to deliver drugs to the intestinal lymphatics and the shift toward the use of these strategies to achieve pharmacokinetic and therapeutic benefits for patients.

Bioengineered Nanomedicines Targeting the Intestinal Fc Receptor Achieve the Improved Glucoregulatory Effect of Semaglutide in a Type 2 Diabetic Mice Model

The oral administration of the glucagon-like peptide-1 analogue, semaglutide, remains a hurdle due to its limited bioavailability. Herein, neonatal Fc receptor (FcRn)-targeted nanoparticles (NPs) were designed to enhance the oral delivery of semaglutide. The nanocarriers were covalently linked to the FcRn-binding peptide FcBP or the affibody molecule ZFcRn that specifically binds to the human FcRn (hFcRn) in a pH-dependent manner. These FcRn-targeted ligands were selected over the endogenous ligands of the receptor (albumin and IgG) due to their smaller size and simpler structure, which could facilitate the transport of functionalized NPs through the tissues. The capacity of FcRn-targeted semaglutide-NPs in controlling the blood glucose levels was evaluated in an hFcRn transgenic mice model, where type 2 diabetes mellitus (T2DM) was induced via intraperitoneal injection of nicotinamide followed by streptozotocin. The encapsulation of semaglutide into FcRn-targeted NPs was translated in an improved glucoregulatory effect in T2DM-induced mice when compared to the oral free semaglutide or nontargeted NP groups, after daily oral administrations for 7 days. Notably, a similar glucose-lowering response was observed between both FcRn-targeted NPs and the subcutaneous semaglutide groups. An increase in insulin pancreatic content and a recovery in β cell mass were visualized in the mice treated with FcRn-targeted semaglutide-NPs. The biodistribution of fluorescently labeled NPs through the gastrointestinal tract demonstrated that the nanosystems targeting the hFcRn are retained longer in the ileum and colorectum, where the expression of FcRn is more prevalent, than nontargeted NPs. Therefore, FcRn-targeted nanocarriers proved to be an effective platform for improving the pharmacological effect of semaglutide in a T2DM-induced mice model.

GLP-1 physiology in obesity and development of incretin-based drugs for chronic weight management

The introduction of the highly potent incretin receptor agonists semaglutide and tirzepatide has marked a new era in the treatment of type 2 diabetes and obesity. With normalisation of glycated haemoglobin levels and weight losses around 15-25%, therapeutic goals that were previously unrealistic are now within reach, and clinical trials have documented that these effects are associated with reduced risk of cardiovascular events and premature mortality. Here, I review this remarkable development from the earliest observations of glucose lowering and modest weight losses with native glucagon-like peptide (GLP)-1 and short acting compounds, to the recent development of highly active formulations and new molecules. I will classify these agents as GLP-1-based therapies in the understanding that these compounds or combinations may have actions on other receptors as well. The physiology of GLP-1 is discussed as well as its mechanisms of actions in obesity, in particular, the role of sensory afferents and GLP-1 receptors in the brain. I provide details regarding the development of GLP-1 receptor agonists for anti-obesity therapy and discuss the possible mechanism behind their beneficial effects on adverse cardiovascular events. Finally, I highlight new pharmacological developments, including oral agents, and discuss important questions regarding maintenance therapy.

Efficacy and Safety of Oral Semaglutide in the Treatment of Type 2 Diabetes: A Meta-Analysis

This study aims to systematically review the efficacy and safety of oral semaglutide in the treatment of type 2 diabetes mellitus (T2DM) and provide a basis for the rational use of the drug in clinical practice. From the database's inception until February 2023, a systematic search was conducted in PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Database, and China Science and Technology Journal Database to identify randomized controlled trials (RCTs) comparing the efficacy of oral semaglutide at dosages of 3, 7, and 14 mg (trial group) against placebo or other positive control drugs (control group) for the treatment of T2DM. Following literature screening and data extraction, the bias risk assessment tool in the Cochrane reviewer handbook 5.1.0 was used to evaluate the literature quality. Meta-analysis was carried out with RevMan 5.4 software. A total of 10 RCTs with 9541 patients were included. The meta-analysis results revealed that compared with placebo or positive control drugs (empagliflozin, sitagliptin, liraglutide, and dulaglutide), oral semaglutide significantly reduced the hemoglobin A1c (HbA1c) in patients (compared to placebo, 3 mg [MD = -0.61%, 95% CI (-0.89, -0.34)], 7 mg [MD = -1.12%, 95% CI (-1.45, -0.79)], 14 mg [MD = -1.08%, 95% CI (-1.32, -0.85)]; compared to positive control drugs (7 mg [MD = -0.26%, 95% CI (-0.38, -0.15)], 14 mg [MD = -0.37%, 95% CI (-0.52, -0.23)]). Oral semaglutide also showed certain advantages over placebo or positive control drugs in terms of weight loss, HbA1c reduction achievement rate, fasting plasma glucose level, and body mass index with overall dose-dependent efficacy. The incidence of nausea, diarrhea, and vomiting caused by oral semaglutide was higher than that of the placebo or positive control drugs, and the incidence of appetite decrease or constipation was higher than that of the placebo. Severe or symptomatic hypoglycemic episodes were reduced compared to positive control drugs. Oral semaglutide has definite clinical benefits of reducing blood glucose, body weight, reducing the risk of hypoglycemia, and with good safety.

Binding sites and design strategies for small molecule GLP-1R agonists

Glucagon-like peptide-1 receptor (GLP-1R) is a pivotal receptor involved in blood glucose regulation and influencing feeding behavior. It has received significant attention in the treatment of obesity and diabetes due to its potent incretin effect. Peptide GLP-1 receptor agonists (GLP-1RAs) have achieved tremendous success in the market, driving the vigorous development of small molecule GLP-1RAs. Currently, several small molecules have entered the clinical research stage. Additionally, recent discoveries of GLP-1R positive allosteric modulators (PAMs) are also unveiling new regulatory patterns and treatment methods. This article reviews the structure and functional mechanisms of GLP-1R, recent reports on small molecule GLP-1RAs and PAMs, as well as the optimization process. Furthermore, it combines computer simulations to analyze structure-activity relationships (SAR) studies, providing a foundation for exploring new strategies for designing small molecule GLP-1RAs.

Approved and Emerging Hormone-Based Anti-Obesity Medications: A Review Article

Obesity is a heterogeneous, complex, and chronic disease that has a detrimental impact on disability-adjusted life years across the globe. Recent advancements in our understanding of gut-brain communication at the molecular level have driven the development of next-generation anti-obesity medications (AOMs). Glucagon-like peptide-1 receptor agonists (GLP1RAs) remain the front-runners in this rapidly evolving landscape of hormone-based AOMs. Two GLP1RAs, namely Liraglutide and Semaglutide, have been approved by the Food and Drug Administration (FDA) and European Medicine Agency (EMA) for use in clinical practice for weight loss. Three oral GLP1RAs, namely Semaglutide, Danuglipron, and Orforglipron, are undergoing advanced clinical trials in individuals with obesity. Amylin receptor agonist (AMYRA) Cagrilintide, when used alone or in combination with Semaglutide, has demonstrated substantial weight reduction in clinical trials. Tirzepatide, a dual agonist for the glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptors, has been observed to be associated with a significant placebo-subtracted weight reduction of 17.8% in a 72-week randomized controlled trial. Novel approaches targeting glucagon signalling have also yielded promising preliminary results. Three long-acting GLP1R/glucagon receptor (GCGR) dual agonists, namely Survodutide, Mazdutide, and Pemvidutide, exhibited significant weight loss in clinical trials. Retatrutide, a GLP1R/GCGR/GIPR tri-agonist, has been associated with a placebo-subtracted weight reduction of -22.1% in a 48-week phase-II trial. As a note of caution, long-term data on such medications' safety and cardiovascular benefits is yet to be ascertained. Our review provides a comprehensive overview of the approved and emerging hormone-based AOMs, highlighting the diversity of options that might become available in the near future.

The role of glucagon-like peptide-1 receptor agonists (GLP1-RAs) in the management of the hypertensive patient with metabolic syndrome: a position paper from the Korean society of hypertension

Obesity is the one of the most important components of metabolic syndrome. Because obesity related hypertension accounts for two thirds of essential hypertension, managing obesity and metabolic syndrome is a crucial task in the management of hypertension. However, the current non-pharmacological therapies have limitations for achieving or maintaining ideal body weight. Recently, glucagon-like peptide-1 receptor agonists (GLP1-RAs) have demonstrated excellent weight control effects, accompanied by corresponding reductions in blood pressure. GLP1-RAs have shown cardiovascular and renal protective effects in cardiovascular outcome trials both in primary and secondary prevention. In this document, the Korean Society of Hypertension intends to remark the current clinical results of GLP1-RAs and recommend the government and health-policy makers to define obesity as a disease and to establish forward-looking policies for GLP1-RA treatment for obesity treatment, including active reimbursement policies.

Gastrointestinal Permeation Enhancers Beyond Sodium Caprate and SNAC - What is Coming Next?

Oral peptide delivery is trending again. Among the possible reasons are the recent approvals of two oral peptide formulations, which represent a huge stride in the field. For the first time, gastrointestinal (GI) permeation enhancers (PEs) are leveraged to overcome the main limitation of oral peptide delivery-low permeability through the intestinal epithelium. Despite some success, the application of current PEs, such as salcaprozate sodium (SNAC), sodium caprylate (C8), and sodium caprate (C10), is generally resulting in relatively low oral bioavailabilities (BAs)-even for carefully selected therapeutics. With several hundred peptide-based drugs presently in the pipeline, there is a huge unmet need for more effective PEs. Aiming to provide useful insights for the development of novel PEs, this review summarizes the biological hurdles to oral peptide delivery with special emphasis on the epithelial barrier. It describes the concepts and action modes of PEs and mentions possible new targets. It further states the benchmark that is set by current PEs, while critically assessing and evaluating emerging PEs regarding translatability, safety, and efficacy. Additionally, examples of novel PEs under preclinical and clinical evaluation and future directions are discussed.

Suitability and Usefulness of a Flexible Dosing Timing of Oral Semaglutide to Maximize Benefit in Clinical Practice: An Expert Panel

From clinical trials and observational data, oral semaglutide has proven to be the most effective second-line oral therapy for the management of patients with type 2 diabetes. This review aims to describe the perspective of an Italian expert panel that addressed the potential challenges arising during the use of oral semaglutide in the free-living conditions of routine clinical care. A group of Italian experts discussed and generated insights into the use of oral semaglutide in clinical practice. Key topics included the effectiveness of oral semaglutide in clinical practice, the positioning of the agent to optimize the treatment benefits, the possibility to adopt flexibility in the administration schedule, critical issues encountered, the role of patient communication and information in the importance of dose escalation and management of adverse events. Available data on efficacy and effectiveness of oral semaglutide from randomized clinical trials and real-world studies were reported, along with factors that determine tolerability and persistence on treatment. The debate over a fixed versus a flexible dosing schedule was critically addressed, providing anecdotical clues from a small case series and a real-world database. Additionally, a set of recommendations for clinicians to consider when prescribing oral semaglutide and during the process of patient monitoring were provided.

Review of ionic liquid and ionogel-based biomaterials for advanced drug delivery

Ionic liquids (ILs) play a crucial role in the design of novel materials. The ionic nature of ILs provides numerous advantages in drug delivery, acting as a green solvent or active ingredient to enhance the solubility, permeability, and binding efficiency of drugs. They could also function as a structuring agent in the development of nano/micro particles for drug delivery, including micelles, vesicles, gels, emulsion, and more. This review summarize the ILs and IL-based gel structures with their advanced drug delivery applications. The first part of review focuses on the role of ILs in drug formulation and the applications of ILs in drug delivery. The second part of review offers a comprehensive overview of recent drug delivery applications of IL-based gel. It aims to offer new perspectives and attract more attention to open up new avenues in the biomedical applications of ILs and IL-based gels.

Efficacy and tolerability of oral semaglutide in Japanese patients with type 2 diabetes mellitus: Analysis report from diabetes specialist clinics

INTRODUCTION

Glucagon-like peptide 1 receptor agonists (GLP1Ras) have emerged as pivotal agents in diabetes management and organ protection. However, their use is limited due to the necessity for injectable administration. The advent of the first oral GLP1Ra (oral semaglutide) in Japan since 2021 is expected to expand its usage. The aim of this study is to survey the efficacy and tolerability of oral semaglutide in clinical practice.

MATERIALS AND METHODS

We retrospectively analyzed 120 outpatients diagnosed with type 2 diabetes mellitus who had received oral semaglutide for >6 months. Changes in clinical parameters during oral semaglutide treatment from baseline to 12 months were analyzed. The inverse probability weighting method using the propensity score was used to evaluate the differences in clinical parameters at 6 months after treatment, based on the patients' obesity levels.

RESULTS

Body weight (BW), glycated hemoglobin A1c (HbA1c), and alanine aminotransferase (ALT) levels at baseline decreased significantly after treatment compared with those at 12 months (P < 0.001, P < 0.001, and P = 0.03, respectively). The patients were divided into two groups using a cutoff baseline body mass index (BMI) of 30.3 kg/m2. Although no significant difference was observed, changes in body weight and HbA1c indicated a potentially greater decrease in the BMI ≧ 30.3 group than that in the BMI < 30.3 group (P = 0.07 and 0.13, respectively). Among 206 registered patients, 25 (12.1%) discontinued oral-semaglutide treatment owing to adverse effects, including gastrointestinal symptoms.

CONCLUSIONS

Oral semaglutide treatment demonstrates efficacy and tolerability for managing type 2 diabetes mellitus in Japan. Significant improvements in metabolic factors induced by oral semaglutide are anticipated, particularly in obese patients.

Tuning the double lipidation of salmon calcitonin to introduce a pore-like membrane translocation mechanism

A widespread strategy to increase the transport of therapeutic peptides across cellular membranes has been to attach lipid moieties to the peptide backbone (lipidation) to enhance their intrinsic membrane interaction. Efforts in vitro and in vivo investigating the correlation between lipidation characteristics and peptide membrane translocation efficiency have traditionally relied on end-point read-out assays and trial-and-error-based optimization strategies. Consequently, the molecular details of how therapeutic peptide lipidation affects it's membrane permeation and translocation mechanisms remain unresolved. Here we employed salmon calcitonin as a model therapeutic peptide and synthesized nine double lipidated analogs with varying lipid chain lengths. We used single giant unilamellar vesicle (GUV) calcein influx time-lapse fluorescence microscopy to determine how tuning the lipidation length can lead to an All-or-None GUV filling mechanism, indicative of a peptide mediated pore formation. Finally, we used a GUVs-containing-inner-GUVs assay to demonstrate that only peptide analogs capable of inducing pore formation show efficient membrane translocation. Our data provided the first mechanistic details on how therapeutic peptide lipidation affects their membrane perturbation mechanism and demonstrated that fine-tuning lipidation parameters could induce an intrinsic pore-forming capability. These insights and the microscopy based workflow introduced for investigating structure-function relations could be pivotal for optimizing future peptide design strategies.

Efficacy and Safety of Escalating the Dose of Oral Semaglutide from 7 to 14 mg: A Single-Center, Retrospective Observational Study

INTRODUCTION

The efficacy and safety of oral semaglutide, the first glucagon-like peptide 1 receptor agonist available in tablet form for the treatment of type 2 diabetes, were established in the phase 3a PIONEER program. However, evidence regarding the titration of oral semaglutide in real-world clinical settings remains insufficient. This study aimed to elucidate the therapeutic advantages of escalating the dose of oral semaglutide from 7 to 14 mg through clinical data analysis.

METHODS

This retrospective observational study was conducted at a single center in Japan, focusing on adults with type 2 diabetes who were initiated on 14 mg oral semaglutide. The primary endpoint was the alteration in HbA1c levels 24 weeks after the initial prescription of 14 mg oral semaglutide. Secondary endpoints included changes in metabolic parameters and the incidence of adverse events.

RESULTS

Data from 66 patients who met the inclusion criteria were analyzed. The mean change in HbA1c levels from baseline to 24 weeks following dose escalation was - 0.5 ± 0.8% [from 7.4 ± 1.0% at baseline to 7.0 ± 0.9% at 24 weeks (p < 0.01)]. Moreover, a significant reduction in body weight of - 2.0 ± 4.4 kg was observed at 24 weeks [from 90.0 ± 20.5 kg at baseline to 88.2 ± 21.4 kg at 24 weeks (p < 0.01)], with 41% of patients achieving at least a 3% reduction compared to baseline. Gastrointestinal disorders emerged as the most prevalent adverse event (10.6%), particularly nausea (7.6%), although predominantly of mild or moderate severity, with no instances of serious adverse events necessitating drug discontinuation.

CONCLUSION

Escalating the dose of oral semaglutide to 14 mg could be an effective approach for enhancing glycemic control and managing body weight in individuals with type 2 diabetes.

Subcutaneous Semaglutide during Breastfeeding: Infant Safety Regarding Drug Transfer into Human Milk

Postpartum mothers and their healthcare providers often face the challenge of limited data regarding the safety of drug therapies during lactation. Pregnancy can lead to sustained weight gain, and obesity can negatively impact both physical and psychological well-being. The introduction of GLP-1 agonists to augment weight loss has become a topic of interest for many postpartum mothers. Our study aims to investigate the transmission of semaglutide into human milk in the first steps to ensure the safety and health of both lactating mothers and their breastfed infants. Semaglutide quantification was performed using high-resolution liquid chromatography-mass spectrometry. InfantRisk Center Human Milk biorepository released milk samples from eight women collected at 0, 12 and 24 h post-semaglutide administration. Semaglutide was extracted using protein precipitation in methanol, followed by chromatographic separation. Linear calibration curves for the method ranged between 2.5-30 ng/mL, with a limit of detection of 1.7 ng/mL and a limit of quantification of 5.7 ng/mL (LLOQ). Semaglutide was not detected in any of the collected human milk samples. A worst-case scenario of the relative infant dose (RID) was calculated using the LLOQ as the drug concentration in milk when considering semaglutide's bioavailability and long-acting dose profile. The maximum RID projected was 1.26%, far below the standard 10% safety threshold. While questions about long-term infant outcomes, the safety of maternal nutrient intake, and the nutrient content of breast milk remain, our findings suggest that semaglutide concentrations in human milk are unlikely to pose clinical concerns for breastfed infants. These results support healthcare providers in making informed decisions regarding postpartum therapeutic interventions.

The Synthesis of SNAC Phenolate Salts and the Effect on Oral Bioavailability of Semaglutide

PURPOSE

Sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) is a well-known penetration enhancer widely used in commercial applications. This study aims to broaden its properties through a novel strategy of converting it into its phenolate salts. The objective is to investigate the synthesis of SNAC phenolate salts, specifically SNAC-choline (SNAC-CH), SNAC-sodium (SNAC-Na), and SNAC-phosphatidylcholine (SNAC-PC), and to explore their potential application in improving the oral absorption of semaglutide.

METHODS

The synthesis of SNAC phenolate salts was confirmed through 1H-NMR, FTIR, and an elemental analysis of C, H, N, and O. In vivo testing was conducted to assess the oral delivery of semaglutide using these synthesized SNAC phenolate salts. Pharmacokinetic (PK) values were measured to evaluate the impact on drug absorption.

RESULTS

The synthesis of SNAC phenolate salts (SNAC-CH, SNAC-Na, and SNAC-PC) was successfully achieved under appropriate conditions, and their structures were confirmed using analytical techniques such as IR, NMR, and CHN elemental analysis. The paradigm of their use was evaluated through an oral pharmacokinetic (PK) in vivo study using SNAC phenolate salts, which did not impair the original SNAC PK values. This suggests that this strategy holds promise as a potential new effective enhancer for oral absorption.

CONCLUSIONS

The utilization of SNAC phenolate salts presents a novel and promising strategy for extending the verity of penetration enhancers' molecules and properties. Synthesizing phenolate salts represents a new chemical strategy that may open new avenues in molecular development. This approach holds future potential to enhance the oral delivery of peptide drugs like semaglutide without compromising therapeutic efficacy. Overall, it offers significant advancements in the field by providing a potential alternative to injectable peptides through oral delivery systems.

Oral Semaglutide in Type 2 Diabetes: Clinical-Metabolic Outcomes and Quality of Life in Real-World Practice

Background: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a novel class of incretin mimetics for treating type 2 diabetes (T2D). This study evaluated the impact of semaglutide, the first oral GLP-1RA, on glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and body composition and anthropometric parameters. Additionally, the effects on cardiovascular risk factors and quality of life (QoL) in T2D patients were assessed. Methods: A prospective observational study with a six-month follow-up was conducted. Clinical parameters, including HbA1c, FPG, anthropometric measurements, blood pressure, cardiovascular risk factors, Diabetes Treatment Satisfaction Questionnaire (DTSQ) responses, and Short Form (36) Health Survey (SF-36) responses, were collected at baseline (T0) and at six months (T1). Results: Sixty-one subjects were enrolled, with there being an average T2D duration of 4.67 ± 3.93 years. Significant decreases were observed in HbA1c (µ = -1.24; SD = 1.33; p < 0.05), FPG (µ = -31.01 mg/dL; SD = 41.71; p < 0.05), body composition and anthropometric parameters (p < 0.05), and cardiovascular risk factors (p < 0.05), with an increase in DTSQ scores (p < 0.05). Conclusions: The administration of 14 mg/day oral semaglutide improved several clinical parameters after six months of treatment. These findings suggest semaglutide is effective in improving glycemic control, weight management, and some cardiovascular risk factors in T2D patients.

Head-to-Head Comparison of Caco-2 Transwell and Gut-on-a-Chip Models for Assessing Oral Peptide Formulations

Oral delivery of potent peptide drugs provides key formulation challenges in the pharmaceutical industry: stability, solubility, and permeability. Intestinal permeation enhancers (PEs) can overcome the low oral bioavailability by improving the drug permeability. Conventional in vitro and ex vivo models for assessing PEs fail to predict efficacy in vivo. Here, we compared Caco-2 cells cultured in the conventional static Transwell model to a commercially available continuous flow microfluidic Gut-on-a-Chip model. We determined baseline permeability of FITC-Dextan 3 kDa (FD3) in Transwell (5.3 ± 0.8 × 10-8 cm/s) vs Chip (3.2 ± 1.8 × 10-7 cm/s). We screened the concentration impact of two established PEs sodium caprate and sucrose monolaurate and indicated a requirement for higher enhancer concentration in the Chip model to elicit equivalent efficacy e.g., 10 mM sodium caprate in Transwells vs 25 mM in Chips. Fasted and fed state simulated intestinal fluids (FaSSIF/FeSSIF) were introduced into the Chip and increased basal FD3 permeability by 3-fold and 20-fold, respectively, compared to 4-fold and 4000-fold in Transwells. We assessed the utility of this model to peptides (Insulin and Octreotide) with PEs and observed much more modest permeability enhancement in the Chip model in line with observations in ex vivo and in vivo preclinical models. These data indicate that microfluidic Chip models are well suited to bridge the gap between conventional in vitro and in vivo models.

Targeting the incretin system in obesity and type 2 diabetes mellitus

Obesity and type 2 diabetes mellitus (T2DM) are widespread, non-communicable diseases that are responsible for considerable levels of morbidity and mortality globally, primarily in the form of cardiovascular disease (CVD). Changes to lifestyle and behaviour have insufficient long-term efficacy in most patients with these diseases; metabolic surgery, although effective, is not practically deliverable on the scale that is required. Over the past two decades, therapies based on incretin hormones, spearheaded by glucagon-like peptide 1 (GLP1) receptor agonists (GLP1RAs), have become the treatment of choice for obesity and T2DM, and clinical evidence now suggests that these agents have benefits for CVD. We review the latest advances in incretin-based pharmacotherapy. These include 'GLP1 plus' agents, which combine the known advantages of GLP1RAs with the activity of additional hormones, such as glucose-dependent insulinotropic peptide, glucagon and amylin, to achieve desired therapeutic goals. Second-generation non-peptidic oral GLP1RAs promise to extend the benefits of GLP1 therapy to those who do not want, or cannot have, subcutaneous injection therapy. We conclude with a discussion of the knowledge gaps that must be addressed before incretin-based therapies can be properly deployed for maximum benefit in the treatment of obesity and T2DM.

A phase 1, randomized, double-blind, placebo-controlled trial investigating the pharmacokinetics, pharmacodynamics, safety and tolerability of oral semaglutide in healthy Chinese subjects

AIM

The trial (NCT04016974) investigated the pharmacokinetics, pharmacodynamics, safety and tolerability of oral semaglutide, the first orally administered glucagon-like peptide-1 analogue for type 2 diabetes, in healthy Chinese subjects.

MATERIALS AND METHODS

This single-centre, multiple-dose, placebo-controlled trial randomized 32 healthy Chinese adults to once-daily oral semaglutide (3 mg escalating to 14 mg) or placebo for 12 weeks. Blood samples were collected regularly during treatment and follow-up. The primary endpoint was the area under the semaglutide concentration-time curve over a dosing interval (0-24 h) at steady state (AUC0-24h,sema,SS). Secondary pharmacokinetic endpoints included the maximum observed semaglutide plasma concentration at steady state (Cmax,sema,SS). Supportive secondary pharmacodynamics endpoints included changes in body weight and fasting plasma glucose.

RESULTS

Treatment with all oral semaglutide doses showed dose-dependent increases in semaglutide exposure in healthy Chinese subjects at steady state, determined by AUC0-24h,sema,SS (233, 552 and 1288 h·nmol/L for 3, 7 and 14 mg of oral semaglutide, respectively) and Cmax,sema,SS. Oral semaglutide treatment was associated with significant reductions in body weight (p = .0001) and fasting plasma glucose (p = .0011) versus placebo at the end of treatment. The safety and tolerability of oral semaglutide were consistent with the known profile of glucagon-like peptide-1 receptor agonists, with no severe or blood-glucose-confirmed symptomatic hypoglycaemic events, serious adverse events or deaths. The most frequent adverse events were gastrointestinal disorders.

CONCLUSIONS

At steady state, oral semaglutide exposure was dose dependent and close to dose proportionality in healthy Chinese subjects. This is consistent with previous clinical pharmacology results for oral semaglutide.

Mechanisms of action and therapeutic applications of GLP-1 and dual GIP/GLP-1 receptor agonists

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are two incretins that bind to their respective receptors and activate the downstream signaling in various tissues and organs. Both GIP and GLP-1 play roles in regulating food intake by stimulating neurons in the brain's satiety center. They also stimulate insulin secretion in pancreatic β-cells, but their effects on glucagon production in pancreatic α-cells differ, with GIP having a glucagonotropic effect during hypoglycemia and GLP-1 exhibiting glucagonostatic effect during hyperglycemia. Additionally, GIP directly stimulates lipogenesis, while GLP-1 indirectly promotes lipolysis, collectively maintaining healthy adipocytes, reducing ectopic fat distribution, and increasing the production and secretion of adiponectin from adipocytes. Together, these two incretins contribute to metabolic homeostasis, preventing both hyperglycemia and hypoglycemia, mitigating dyslipidemia, and reducing the risk of cardiovascular diseases in individuals with type 2 diabetes and obesity. Several GLP-1 and dual GIP/GLP-1 receptor agonists have been developed to harness these pharmacological effects in the treatment of type 2 diabetes, with some demonstrating robust effectiveness in weight management and prevention of cardiovascular diseases. Elucidating the underlying cellular and molecular mechanisms could potentially usher in the development of new generations of incretin mimetics with enhanced efficacy and fewer adverse effects. The treatment guidelines are evolving based on clinical trial outcomes, shaping the management of metabolic and cardiovascular diseases.