Liraglutide in oral antidiabetic drug combination therapy

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.

Quercetin and Kaempferol as Multi-Targeting Antidiabetic Agents against Mouse Model of Chemically Induced Type 2 Diabetes

Diabetes, a multifactorial metabolic disorder, demands the discovery of multi-targeting drugs with minimal side effects. This study investigated the multi-targeting antidiabetic potential of quercetin and kaempferol. The druggability and binding affinities of both compounds towards multiple antidiabetic targets were explored using pharmacokinetic and docking software (AutoDock Vina 1.1.2). Our findings showed that quercetin and kaempferol obey Lipinski's rule of five and exhibit desirable ADMET (absorption, distribution, metabolism excretion, and toxicity) profiles. Both compounds showed higher binding affinities towards C-reactive protein (CRP), interleukin-1 (IL-1), dipeptidyl peptidase-4 (DPP-IV), peroxisome proliferator-activated receptor gamma (PPARG), protein tyrosine phosphatase (PTP), and sodium-glucose co-transporter-1 (SGLT-1) compared to metformin (the positive control). Both quercetin and kaempferol inhibited α-amylase activity (in vitro) up to 20.30 ± 0.49 and 37.43 ± 0.42%, respectively. Their oral supplementation significantly reduced blood glucose levels (p < 0.001), improved lipid profile (p < 0.001), and enhanced total antioxidant status (p < 0.01) in streptozotocin-nicotinamide (STZ-NA)-induced diabetic mice. Additionally, both compounds significantly inhibited the proliferation of Huh-7 and HepG2 (cancer cells) (p < 0.0001) with no effect on the viability of Vero cell line (non-cancer). In conclusion, quercetin and kaempferol demonstrated higher binding affinities towards multiple targets than metformin. In vitro and in vivo antidiabetic potential along with the anticancer activities of both compounds suggest promise for further development in diabetes management. The combination of both drugs did not show a synergistic effect, possibly due to their same target on the receptors.

Comparative effects of glucagon-like peptide-1 receptors agonists, 4-dipeptidyl peptidase inhibitors, and metformin on metabolic syndrome

AIMS

To assess the comparative effects of glucagon-like peptide-1 receptor agonists (GLP-1RA), 4-dipeptidyl peptidase inhibitors (DPP-4I), and metformin treatment during one year on metabolic syndrome (MetS) components and severity in MetS patients.

METHODS

Prospective study (n = 6165 adults) within the frame of PREDIMED-Plus trial. The major end-point was changes on MetS components and severity after one- year treatment of GLP-1RA, DPP-4I, and metformin. Anthropometric measurements (weight, height and waist circumference), body mass index (BM), and blood pressure were registered. Blood samples were collected after overnight fasting. Plasma glucose, glycosylated hemoglobin (HbA1c), plasma triglycerides and cholesterol were measured. Dietary intakes as well as physical activity were assessed through validated questionnaires.

RESULTS

MetS parameters improved through time. The treated groups improved glycaemia compared with untreated (glycaemia ∆ untreated: -1.7 mg/dL(± 13.5); ∆ metformin: - 2.5(± 23.9) mg/dL; ∆ DPP-4I: - 4.5(± 42.6); mg/dL ∆ GLP-1RA: - 4.3(± 50.9) mg/dL; and HbA1c: ∆ untreated: 0.0(± 0.3) %; ∆ metformin: - 0.1(± 0.7) %; ∆ DPP-4I: - 0.1(± 1.0) %; ∆ GLP-1RA: - 0.2(± 1.2) %. Participants decreased BMI and waist circumference. GLP-1RA and DPP-4I participants registered the lowest decrease in BMI (∆ untreated: -0.8(± 1.6) kg/m²; ∆ metformin: - 0.8(± 1.5) kg/m²; ∆ DPP-4I: - 0.6(± 1.3) kg/m²; ∆ GLP-1RA: - 0.5(± 1.2) kg/m². and their waist circumference (∆ untreated: -2.8(± 5.2) cm; ∆ metformin: - 2.6(± 15.2) cm; ∆ DPP-4I: - 2.1(± 4.8) cm; ∆ GLP-1RA: - 2.4(± 4.1) cm.

CONCLUSION

In patients with MetS and healthy lifestyle intervention, those treated with GLP-1RA and DPP-4I obtained better glycemic profile. Anthropometric improvements were modest.

Clinical Considerations When Initiating and Titrating Insulin Degludec/Liraglutide (IDegLira) in People with Type 2 Diabetes

Therapeutic inertia is a substantial obstacle to the initiation of insulin therapy in people with uncontrolled type 2 diabetes (T2D). This effect has in part been perpetuated by concerns over the impact of a burdensome regimen and the increased risk of hypoglycemia and body weight gain often associated with insulin use. An effective, yet simple, less burdensome regimen with a lower risk of body weight gain and hypoglycemia compared with an insulin-only regimen, may help to address these concerns more effectively. We review the available clinical and real-world data on IDegLira, a once-daily, injectable, fixed-ratio combination of insulin degludec (degludec) and the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide, in people with T2D. Evidence from the comprehensive DUAL clinical trial program suggests an advantage of IDegLira over traditional insulin therapies in a number of clinical outcomes, including maintenance of glycemic control, achievement of glycemic targets, reducing the risk of hypoglycemia, and body weight loss. These findings were demonstrated in participants with T2D irrespective of prior GLP-1RA and insulin use. Furthermore, the individual components of IDegLira have confirmed safety (degludec) or significant benefit in terms of improvement of cardiovascular risk (liraglutide). As an injectable therapy that is simple to titrate, IDegLira has the potential to optimize the ability to achieve relevant glycemic targets, and offers a suitable treatment option for people with T2D requiring insulin therapy who are at risk of hypoglycemia or weight gain.

Gene therapy of type 2 diabetes mellitus: state of art

Type 2 diabetes mellitus (T2DM) and other metabolic diseases are essential links in the structure of morbidity and mortality in the modern world. The accepted strategy for the correction of T2DM and insulin resistance is drug therapy aimed at delivering insulin from the outside, stimulating the secretion of own insulin and reducing the concentration of blood glucose. However, modern studies demonstrate a great potential for the use of gene therapy approaches for the correction of T2DM and insulin resistance. In the present review, the main variants of plasmid gene therapy of T2DM using the genes of adiponectin and type 1 glucagon-like peptide, as well as the main variants of viral gene therapy of T2DM using the genes of type 1 and leptin are considered. T2DM gene therapy is currently not ready to enter into routine clinical practice, but, subject to improvements in delivery systems, it can be a powerful link in combination therapy for diabetes.

Insulin degludec/liraglutide (IDegLira) for the treatment of type 2 diabetes

The progressive nature of type 2 diabetes necessitates that treatment is intensified as the disease advances. Several studies have shown that basal insulin and glucagon-like peptide-1 receptor agonists (GLP-1RAs) can be used in combination to successfully improve glycemic control and this combination is increasingly being considered as an alternative to intensification with prandial insulin. Insulin degludec/liraglutide (IDegLira) is the first fixed-ratio combination of a basal insulin and a GLP-1RA in a single formulation. Here we consider the benefits and potential limitations of such a combination, focusing on the unique modes of action of insulin degludec and the once-daily GLP-1RA liraglutide. IDegLira offers an efficacious combination therapy (mean end-of-trial HbA_1c was 6.4-6.9% across the five completed Phase 3 trials), which was well-tolerated in clinical trials. The complementary modes of action resulted in a low rate of hypoglycemia and no weight gain in insulin-treated patients. As a once-daily injection with effects on both fasting and post prandial hyperglycemia, IDegLira has the potential to help many patients reach glycemic target (60-81% of patients achieved HbA_1c <7% in clinical trials).

Pharmacological characterization and antidiabetic activity of a long-acting glucagon-like peptide-1 analogue conjugated to an antithrombin III-binding pentasaccharide

AIMS

To examine the biological characteristics of a novel glucagon-like peptide-1 (GLP-1) conjugate, in which an antithrombin III (ATIII)-binding pentasaccharide is conjugated to d-Ala(8) GLP-1 using a tetraethylene glycol linker.

METHODS

We assessed GLP-1 receptor binding, cAMP generation and insulin secretory activity of the GLP-1 conjugate in vitro. Circulating half-life, glucose homeostatic and subchronic therapeutic effectiveness were then examined in vivo.

RESULTS

The half-life of the GLP-1 conjugate in mice was ∼11 h. In vitro insulin secretion from clonal β cells and islets was increased (p < 0.001) by the conjugate. The conjugate had half maximum effective concentration values of 1.3 × 10(-7) and 9.9 × 10(-8)  M for displacement of (125) I-GLP-1 in competitive GLP-1 receptor binding and cAMP generation, respectively. Glucose tolerance in normal mice, immediately and 4 h after conjugate injection, resulted in significant (p < 0.001) improvements in blood glucose. These effects persisted for >48 h after administration. Daily treatment (21 days) of high-fat-fed and ob/ob mice with 25 nmol/kg conjugate resulted in significant improvement in glucose tolerance (p < 0.001) and reductions in glycated haemoglobin (HbA1c; p < 0.01) equivalent to or better than with exenatide or liraglutide. Treatment of C57BL/KsJ db/db mice for 15 days with 100 nmol/kg conjugate significantly (p < 0.001) reduced glucose and raised plasma insulin. Oral glucose tolerance was significantly (p < 0.001) improved and both 24-h glucose profile (p < 0.001) and HbA1c levels (p < 0.001) were reduced. Islet size (p < 0.001) and pancreatic insulin content were increased without change of islet cell proliferation or apoptosis.

CONCLUSION

These data show that d-Ala(8) GLP-1(Lys(37) ) pentasaccharide exerts significant antidiabetic actions and has a projected pharmacokinetic/pharmacodynamic profile that merits further evaluation in humans for a possible once-weekly dosing regimen.

Synthesis and Evaluation of a Series of Long-Acting Glucagon-Like Peptide-1 (GLP-1) Pentasaccharide Conjugates for the Treatment of Type 2 Diabetes

The present study details the development of a family of novel D-Ala(8) glucagon-like peptide-1 (GLP-1) peptide conjugates by site specific conjugation to an antithrombin III (ATIII) binding carrier pentasaccharide through tetraethylene glycol linkers. All conjugates were found to possess potent insulin-releasing activity. Peptides with short linkers (<25 atoms) conjugated at Lys(34) and Lys(37) displayed strong GLP-1 receptor (GLP-1-R) binding affinity. All D-Ala(8) GLP-1 conjugates exhibited prominent glucose-lowering action. Biological activity of the Lys(37) short-linker peptide was evident up to 72 h post-injection. In agreement, the pharmacokinetic profile of this conjugate (t1/2 , 11 h) was superior to that of the GLP-1-R agonist, exenatide. Once-daily injection of the Lys(37) short-linker peptide in ob/ob mice for 21 days significantly decreased food intake and improved HbA1c and glucose tolerance. Islet size was decreased, with no discernible change in islet number. The beneficial effects of the Lys(37) short-linker peptide were similar to or better than either exenatide or liraglutide, another GLP-1-R agonist. In conclusion, GLP-1 peptides conjugated to an ATIII binding carrier pentasaccharide have a substantially prolonged bioactive profile compatible for possible once-weekly treatment of type 2 diabetes in humans.

Regulation of glucose homeostasis by GLP-1

Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics.

Regulation of glucose homeostasis by GLP-1

Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics.

The design of the liraglutide clinical trial programme

Liraglutide is a once-daily human glucagon-like peptide-1 analogue used in the treatment of type 2 diabetes (T2D). It has been prospectively investigated in a series of multinational, randomised, controlled phase 3 trials (the Liraglutide Effect and Action in Diabetes programme), as well as in an additional direct head-to-head study with sitagliptin. These trials were designed to clarify the use and safety of liraglutide in clinical practice across the treatment continuum of T2D, and consequently involved a large number and diverse range of patients. These studies also included active comparisons against antidiabetic agents including metformin, rosiglitazone, glimepiride, insulin glargine, exenatide and sitagliptin, and therefore have helped to examine clinical differences and similarities between liraglutide and these commonly used agents.

Non-glycaemic effects mediated via GLP-1 receptor agonists and the potential for exploiting these for therapeutic benefit: focus on liraglutide

The glucagon-like peptide-1 receptor agonists (GLP-1 RAs) liraglutide and exenatide can improve glycaemic control by stimulating insulin release through pancreatic β-cells in a glucose-dependent manner. GLP-1 receptors are not restricted to the pancreas; therefore, GLP-1 RAs cause additional non-glycaemic effects. Preclinical and clinical trial data suggest a multitude of additional beneficial effects related to GLP-1 RA therapy, including improvements in β-cell function, systolic blood pressure and body weight. These effects are of a particular advantage to patients with type 2 diabetes, as most are affected by β-cell dysfunction, obesity and hypertension. Transient gastrointestinal adverse events, such as nausea and diarrhoea, are also common. To improve gastrointestinal tolerability, an incremental dosing approach is used with liraglutide and exenatide twice daily. A potential protective role for GLP-1 RAs in the cardiovascular and central nervous systems has been suggested from animal studies and short-term clinical trials. These effects and other safety aspects of GLP-1 therapy are currently being investigated in ongoing long-term clinical studies.

Liraglutide: from clinical trials to clinical practice

Liraglutide, a once-daily glucagon-like peptide-1 receptor agonist, is approved for use as monotherapy in the USA and Japan (but not in Europe or Canada) and in combination with selected oral agents (all regions) for the treatment of patients with type 2 diabetes. Guidance from local advisory bodies is emerging on the most appropriate place for liraglutide in the treatment pathway. It is apparent from its phase 3 clinical trial programme that liraglutide provides superior glycaemic control compared with that achieved with other antidiabetic agents used early in the treatment pathway (e.g. glimepiride and sitagliptin). Key additional benefits include a low incidence of hypoglycaemia and clinically relevant weight loss, although these benefits may be ameliorated by concomitant sulphonylurea (SU) treatment and, in the case of hypoglycaemia, reduction of the SU dose may be necessary. Overall, the profile of liraglutide is similar and, in some aspects, superior to twice-daily exenatide. The implementation of liraglutide therapy is straightforward, with simple dose titration from the starting dose of 0.6 to 1.2 mg/day after 1 week; some patients may benefit from additional titration to 1.8 mg/day. Treatment is self-administered by subcutaneous injection. This contrasts with other agents used early in the treatment pathway, but clinical data suggest patients' overall treatment satisfaction with liraglutide is similar (1.2 mg) or better (1.8 mg) than that with sitagliptin despite differing administration methods. Some patients may experience nausea when initiating liraglutide treatment, but the titration regimen is designed to improve tolerability and clinical data indicate nausea is transient.