Molecular simulation of zwitterionic polypeptides on protecting glucagon-like peptide-1 (GLP-1).

Owing to their anti-fouling properties, zwitterionic polypeptides demonstrate great advantage on protecting protein drugs. When conjugated to glucagon-like peptide-1 (GLP-1), a drug for type-II diabetes, zwitterionic polypeptides confer better pharmacokinetics than uncharged counterparts. However, its microscopic mechanism is still unclear due to the complicated conformational space. To address this challenge, this work explored the interaction modes of GLP-1 with the unconnected repeat units, instead of the full-length polypeptides. The three repeat units are two zwitterionic pentapeptides VPKEG and VPREG, and one uncharged control VPGAG. Our molecular simulations revealed that the helical conformation of GLP-1 was stabilized by adding 40 polypeptides. Both VPGAG and VPREG formed dense packing shells around GLP-1, but the driving forces were hydrophobic and electrostatic interactions, respectively. In contrast, the packing shell composed of VPKEG was most loose, while could still stabilize GLP-1. The moderate electrostatic interactions endowed VPKEG an anti-fouling property, thereby avoiding non-specific interaction with other amino acids. The strong electrostatic interactions exerted by arginine promoted atomic contacts between VPREG and other residues, making it as "hydrophobic" as VPGAG. In summary, the combination of hydrophobic and moderate electrostatic interactions in VPKEG brings about a subtle balance between stabilizing GLP-1 and avoiding non-specific interaction.

Albumin-binding domain extends half-life of glucagon-like peptide-1.

Glucagon-like peptide-1 (GLP-1) is considered to be a promising peptide for the treatment of type 2 diabetes mellitus (T2DM). However, the extremely short half-life of GLP-1 limits its clinical application. Albumin-binding domain (ABD) with high affinity for human serum albumin (HSA) has been used widely for half-life extension of therapeutic peptides and proteins. In the present study, novel GLP-1 receptor agonists were designed by genetic fusion of GLP-1 to three kinds of ABDs with different affinities for HSA: GA3, ABD035 and ABDCon. The bioactivities and half-lives of ABD-fusion GLP-1 proteins with different types and lengths of linkers were investigated in vitro and in vivo. The results demonstrated that ABD-fusion GLP-1 proteins could bind to HSA with high affinity. The blood glucose-lowering effect of GLP-1 was significantly improved and sustained by fusion to ABD. Meanwhile, the fusion proteins significantly inhibited food intake, which was beneficial for T2DM and obesity treatment. The half-life of GLP-1 was substantially extended by virtue of ABD. The in vivo results also showed that a longer linker inserted between GLP-1 and ABD resulted in a higher blood glucose-lowering effect. The fusion proteins generated by fusion of GLP-1 to GA3, ABD035 and ABDCon exhibited similar bioactivities and pharmacokinetics in vivo. These findings demonstrate that ABD-fusion GLP-1 proteins retain the bioactivities of natural GLP-1 and can be further developed for T2DM treatment and weight loss. It also indicates that the ABD-fusion strategy can be generally applicable to any peptide or protein, to improve pharmacodynamic and pharmacokinetic properties.

Pharmacokinetics of exogenous GIP(1-42) in C57Bl/6 mice; Extremely rapid degradation but marked variation between available assays.

Like other peptide hormones, glucose-dependent insulinotropic polypeptide (GIP) is rapidly cleared from the circulation. Dipeptidyl peptidase-4 (DPP-4) is known to be involved. Information on the overall pharmacokinetics of GIP in rodents is, however, lacking. We investigated the pharmacokinetics of exogenous GIP after intravenous, subcutaneous and intraperitoneal injection with and without DPP-4 inhibition in conscious female C57Bl/6 mice. Secondly, we compared total and intact GIP levels measured by an in-house RIA and commercially available ELISA kits to determine the suitability of these methods for in vivo and in vitro measurements. GIP half-life following intravenous injection amounted to 93 ± 2 s, which was extended to 5 ± 0.6 min by inhibition of DPP-4. Intact GIP levels following subcutaneous and intraperitoneal GIP administration were approximately 15 % of total GIP. The area under the curve of intact GIP (GIP exposure) following GIP injection was significantly increased by DPP-4 inhibition, whereas total GIP levels remained unchanged. We found significant variation between measurements of total, but not intact GIP performed with our in-house RIA and ELISAs in samples obtained after in vivo administration of GIP. Different preanalytical sample preparation (EDTA plasma, heparin plasma, assay buffer and PBS) significantly influenced results for all ELISA kits used. Thus, in experiments involving exogenous GIP(1-42) administration in mice, it is important to consider that this will result in a very low ratio of intact:total peptide but co-administration of a DPP-4 inhibitor greatly elevates this ratio. Furthermore, for comparison of GIP levels, it is essential to maintain uniformity concerning assay methodology and sample preparation.

Zwitterionic Polymer Conjugated Glucagon-like Peptide-1 for Prolonged Glycemic Control.

Glucagon-like peptide-1 (GLP-1) is of particular interest for treating type 2 diabetes mellitus (T2DM), as it induces insulin secretion in a glucose-dependent fashion and has the potential to facilitate weight control. However, native GLP-1 is a short incretin peptide that is susceptible to fast proteolytic inactivation and rapid clearance from the circulation. Various GLP-1 analogs and bioconjugation of GLP-1 analogs have been developed to counter these issues, but these modifications are frequently accompanied by the sacrifice of potency and the induction of immunogenicity. Here, we demonstrated that with the conjugation of a zwitterionic polymer, poly(carboxybetaine) (pCB), the pharmacokinetic properties of native GLP-1 were greatly enhanced without serious negative effects on its potency and secondary structure. The pCB conjugated GLP-1 further provided glycemic control for up to 6 days in a mouse study. These results illustrate that the conjugation of pCB could realize the potential of using native GLP-1 for prolonged glycemic control in treating T2DM.

Prolonged half-life of small-sized therapeutic protein using serum albumin-specific protein binder.

Many small-sized proteins and peptides, such as cytokines and hormones, are clinically used for the treatment of a variety of diseases. However, their short half-life in blood owing to fast renal clearance usually results in a low therapeutic efficacy and frequent dosing. Here we present the development of a human serum albumin (HSA)-specific protein binder with a binding affinity of 4.3nM through a phage display selection and modular evolution approach to extend the blood half-life of a small-sized therapeutic protein. As a proof-of-concept, the protein binder composed of LRR (Leucine-rich repeat) modules was genetically fused to the N-terminus of Glucagon-like Peptide-1 (GLP-1). The fused GLP-1 was shown to have a significantly improved pharmacokinetic property: The terminal half-life of the fused GLP-1 increased to approximately 10h, and the area under the curve was 5-times higher than that of the control. The utility and potential of our approach was demonstrated by the efficient control of the blood glucose level in type-2 diabetes mouse models using the HSA-specific protein binder-fused GLP-1 over a prolonged time period. The present approach can be effectively used in enhancing the efficacy of small-sized therapeutic proteins and peptides through an enhanced blood circulation time.

Sustained release and pharmacologic evaluation of human glucagon-like peptide-1 and liraglutide from polymeric microparticles.

The GLP1-receptor agonists exert regulatory key roles in diabetes, obesity and related complications. Here we aimed to develop polymeric microparticles loaded with homologous human GLP1 (7-37) or the analogue liraglutide. Peptide-loaded microparticles were prepared by a double emulsion and solvent evaporation process with a set of eight polymers based on lactide (PLA) or lactide-glycolide (PLGA), and evaluated for particle-size distribution, morphology, in vitro release and pharmacologic activity in mice. The resulting microparticles showed size distribution of about 30-50 µm. The in vitro kinetic release assays showed a sustained release of the peptides extending up to 30-40 days. In vivo evaluation in Swiss male mice revealed a similar extension of glycemic and body weight gain modulation for up to 25 days after a single subcutaneous administration of either hGLP1-microparticles or liraglutide-microparticles. Microparticles-loaded hGLP1 shows equivalent in vivo pharmacologic activity to the microparticles-loaded liraglutide.

The chronic administration of two novel long-acting Xenopus glucagon-like peptide-1 analogs xGLP159 and xGLP296 potently improved systemic metabolism and glycemic control in rodent models.

We here reported 2 novel Xenopus glucagon-like peptide-1 (xGLP-1) analogs, xGLP159 and xGLP296, whose therapeutic effects on metabolic efficacy and glycemic control were evaluated in rodents. The in vitro potency of xGLP159 and xGLP296 were investigated on human embryonic kidney 293 cells. The acute glucose-lowering and insulinotropic effects of xGLP159 and xGLP296 were assessed in the Institute of Cancer Research, Kunming, and diabetic (db/db) mice. The pharmacokinetic profiles of xGLP159 and xGLP296 were confirmed on Sprague-Dawley (SD) rats and their long-acting hypoglycemic and anorectic effects were evaluated in db/db mice. Chronic treatment effects of xGLP159 and xGLP296 were evaluated in diet-induced obese (DIO) mice and db/db mice. The results showed that xGLP159 and xGLP296 exhibited comparable receptor activation potency, hypoglycemic effect, and insulinotropic activity to liraglutide. The enhanced half-lives of xGLP159 and xGLP296 in SD rats (5.1 and 5.8 h, respectively) resulted in prolonged anti-db/db durations in db/db mice. Three weeks' administration of xGLP159 and xGLP296 normalized glucose tolerance and adiposity in DIO mice. Furthermore, 11-wk treatment of xGLP159 and xGLP296 corrected hyperglycemia and improved pancreatic function in db/db mice. These preclinical studies supported xGLP159 and xGLP296 as promising candidates for the treatment of metabolic diseases.-Han, J., Meng, T., Chen, X., Han, Y., Fu, J., Zhou, F., Fei, Y., Li, C. The chronic administration of two novel long-acting Xenopus glucagon-like peptide-1 analogs xGLP159 and xGLP296 potently improved systemic metabolism and glycemic control in rodent models.

Peptide-oligourea hybrids analogue of GLP-1 with improved action in vivo.

Peptides have gained so much attention in the last decade that they are now part of the main strategies, with small molecules and biologics, for developing new medicines. Despite substantial progress, the successful development of peptides as drugs still requires a number of limitations to be addressed, including short in vivo half-lives and poor membrane permeability. Here, we describe the use of oligourea foldamers as tool to improve the pharmaceutical properties of GLP-1, a 31 amino acid peptide hormone involved in metabolism and glycemic control. Our strategy consists in replacing four consecutive amino acids of GLP-1 by three consecutive ureido residues by capitalizing on the structural resemblance of oligourea and α-peptide helices. The efficacy of the approach is demonstrated with three GLP-1-oligourea hybrids showing prolonged activity in vivo. Our findings should enable the use of oligoureas in other peptides to improve their pharmaceutical properties and may provide new therapeutic applications.

Effective nose-to-brain delivery of exendin-4 via coadministration with cell-penetrating peptides for improving progressive cognitive dysfunction.

In a recent study, we demonstrated the potential of a cell-penetrating peptide (CPP) penetratin to deliver the peptide drug insulin to the brain via nasal administration, and its pharmacological effect on the mild cognitive dysfunction in senescence-accelerated mouse (SAMP8). However, the therapeutic potential of intranasal insulin administration was attenuated when applied to the aged SAMP8 with severe cognitive dysfunction. The present study, therefore, aimed to overcome the difficulty in treating severe cognitive dysfunction using insulin by investigating potential alternatives, glucagon-like peptide-1 (GLP-1) receptor agonists such as exendin-4. Examination using normal ddY mice demonstrated that the distribution of exendin-4 throughout the brain was dramatically increased by intranasal coadministration with the L-form of penetratin. The activation of hippocampal insulin signaling after the simultaneous nose-to-brain delivery of exendin-4 and an adequate level of insulin were confirmed by analyzing the phosphorylation of Akt. Furthermore, spatial learning ability, evaluated in the Morris water maze test after daily administration of exendin-4 with L-penetratin and supplemental insulin for 4 weeks, suggested therapeutic efficacy against severe cognitive dysfunction. The present study suggests that nose-to-brain delivery of exendin-4 with supplemental insulin, mediated by CPP coadministration, shows promise for the treatment of progressive cognitive dysfunction in SAMP8.

The Pharmacokinetic Properties of Glucagon-like Peptide-1 Receptor Agonists and Their Mode and Mechanism of Action in Patients with Type 2 Diabetes.

Once-weekly (OW) glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have demonstrated improved glycemic control in patients with type 2 diabetes (T2D), and some have a number of other benefits, including weight loss, improvements in blood pressure and lipid profiles, and cardiovascular protection. They also provide a therapy option with a low risk of hypoglycemia, an attractive choice for many patients. Molecular structure and pharmacokinetic properties vary among GLP-1 RAs, with some more closely related than others to native glucagon-like peptide-1 (GLP-1). OW GLP-1 RAs have various modifications to their molecular structure that make the molecules resistant to degradation by dipeptidyl peptidase-4 (DPP-4), increasing the half-life of these drugs and making them suitable for OW administration. These differences in the molecular structures and pharmacokinetic properties between the various OW GLP-1 RAs help to explain the differences in efficacy, mechanisms, and safety profiles among the drugs, and these considerations can help primary care physicians to optimize prescribing practices.

Long-Acting Release Microspheres Containing Novel GLP-1 Analog as an Antidiabetic System.

Glucagon-like peptide 1 (GLP-1) has recently received significant attention as an efficacious way to treat diabetes mellitus. However, the short half-life of the peptide limits its clinical application in diabetes. In our previous study, a novel GLP-1 analog (PGLP-1) with a longer half-life was synthesized and evaluated. Herein, we prepared the PGLP-1-loaded poly(d,l-lactide- co-glycolide) microspheres to achieve long-term effects on blood glucose control. The incorporation of zinc ion into the formulation can effectively decrease the initial burst release, and a uniform drug distribution was obtained, in contrast to native PGLP-1 encapsulated microspheres. We demonstrated that the solubility of the drug encapsulated in microspheres played an important role in in vitro release behavior and drug distribution inside the microspheres. The Zn-PGLP-1 microspheres had a prominent acute glucose reduction effect in the healthy mice. A hypoglycemic effect was observed in the streptozotocin (STZ) induced diabetic mice through a 6-week treatment of Zn-PGLP-1-loaded microspheres. Meanwhile, the administration of Zn-PGLP-1 microspheres led to the ß-cell protection and stimulation of insulin secretion. The novel GLP-1 analog-loaded sustained microspheres may greatly improve patient compliance along with a desirable safety feature.

Is glucagon-like peptide-1 fully protected by the dipeptidyl peptidase 4 inhibitor sitagliptin when administered to patients with type 2 diabetes?

AIM: To evaluate the relationship between plasma dipeptidyl-peptidase 4 (DPP-4) activity and its protection of glucagon-like peptide-1 (GLP-1) using the DPP-4 inhibitor sitagliptin. METHODS: On four separate days, patients with type 2 diabetes (T2D) (n = 8; age: 59.9 ±10.8 [mean ±SD] years; body mass index [BMI]: 28.8 ±4.6 kg/m2 ; glycated haemoglobin A1c [HbA1c]: 43.1 ±0.5 mmol/mol [6.6% ±1.7%]) received a 380-minute continuous intravenous infusion of GLP-1 (1.0 pmol × kg bodyweight-1 × minutes-1 ) and a double-blind, single-dose oral administration of sitagliptin in doses of 0 (placebo), 25, 100 and 200 mg. RESULTS: Plasma DPP-4 activity decreased compared to baseline (placebo) with increasing doses of sitagliptin (P < .01), reaching a maximal inhibition with the 100 mg dose. Levels of intact GLP-1 increased with increasing doses of sitagliptin from placebo to 100 mg (area under curve [AUC] 7.2 [95%, CI; 12.1, 16.4] [placebo], 10.7 [16.1, 21.4] [25 mg], 11.7 [17.8, 23.6] [100 mg] nmol/L × 360 minutes [P < .01]), but no further increase in intact GLP-1 levels was observed with 200 mg of sitagliptin (11.5 [17.6, 23.4] nmol/L × 360 minutes) (P = .80). CONCLUSION: Our findings suggest that the sitagliptin dose of 100 mg is sufficient to inhibit both plasma and membrane-bound DPP-4 activity, presumably also leading to complete protection of endogenous GLP-1 in patients with T2D.

[Metformin is a possible glucagon-like peptide 1 stimulator].

Metformin is an oral anti-hyperglycaemic drug used as first-line treatment of Type 2 diabetes. It is more effective when administered orally than when administered intravenously, and metformin formulations, which prolong the time residing in the gut are the most potent. This indicates that the intestine plays an essential role in metformin's mode of action. Metformin also increases plasma concentrations of the glucose-lowering gut incretin hormone glucagon-like peptide-1 (GLP-1). This metformin-induced GLP-1 increment may constitute an important link between the gut and the glucose-lowering effect of metformin.

Glucagon-Like Peptide-1 (GLP-1)-Based Therapeutics: Current Status and Future Opportunities beyond Type†2 Diabetes.

Glucagon-like peptide-1 (GLP-1) is secreted by intestinal L-cells following food intake, and plays an important role in glucose homeostasis due to its stimulation of glucose-dependent insulin secretion. Further, GLP-1 is also associated with protective effects on pancreatic ß-cells and the cardiovascular system, decreased appetite, and weight loss, making GLP-1 derivatives an exciting treatment for type 2 diabetes and obesity. Despite these benefits, wild-type GLP-1 exhibits a short circulation time due to its poor metabolic stability and rapid renal clearance, and must be administered by injection, making it a poor therapeutic agent. Many strategies have been used to improve the circulation time of GLP-1 (e.g., mutations, unnatural amino acids, depot formulations, use of exendin-4 sequences, and fusions with high-molecular-weight proteins or polymers), with its therapeutic utility further improved by adding agonist activity for gastric inhibitory peptide and glucagon receptors. This minireview focuses on strategies that have been used to improve the pharmacokinetics of GLP-1 and provides an overview of GLP-1-based therapeutics in the pipeline.

Peptide Half-Life Extension: Divalent, Small-Molecule Albumin Interactions Direct the Systemic Properties of Glucagon-Like Peptide 1 (GLP-1) Analogues.

Noncovalent binding of biopharmaceuticals to human serum albumin protects against enzymatic degradation and renal clearance. Herein, we investigated the effect of mono- or divalent small-molecule albumin binders for half-life extension of peptides. For proof-of-principle, the clinically relevant glucagon-like peptide 1 (GLP-1) was functionalized with diflunisal, indomethacin, or both. In vitro, all GLP-1 analogues had subnanomolar GLP-1 receptor potency. Surface plasmon resonance revealed that both small molecules were able to confer albumin affinity to GLP-1 and indicated that affinity is increased for divalent analogues. In lean mice, the divalent GLP-1 analogues were superior to monovalent analogues with respect to control of glucose homeostasis and suppression of food intake. Importantly, divalent GLP-1 analogues showed efficacy comparable to liraglutide, an antidiabetic GLP-1 analogue that carries a long-chain fatty acid. Finally, pharmacokinetic investigations of a divalent GLP-1 analogue demonstrated a promising gain in circulatory half-life and absorption time compared to its monovalent equivalent.

BPI-3016, a novel long-acting hGLP-1 analogue for the treatment of Type 2 diabetes mellitus.

Glucagon-like peptide-1 (GLP-1) analogues have been commonly used as add-on medications for patients with Type 2 diabetes mellitus (T2DM). Currently, the development of long-acting GLP-1 analogues which allow the freedom and flexibility of once-weekly injections while maintaining their potency for a relatively long period has become the mainstream. Here, we successfully developed a long-acting human GLP-1(7-37) analogue (BPI-3016) with significantly extended half-life and increased resistance to dipeptidyl peptidase IV (DPP-IV) cleavage by structural modifications of human GLP-1. In vitro activity of BPI-3016 including GLP-1 receptor affinity and stimulation of cyclic adenosine monophosphate (cAMP) production was measured. In vivo activity of BPI-3016 such as its effects on glycemic control, ß-cell mass and body weight was evaluated in ob/ob mice, db/db mice, and spontaneous diabetic cynomolgus monkeys. The results indicated that BPI-3016 preserved receptor affinity to GLP receptors, and was capable of stimulating cAMP production. In in vivo pharmacokinetic study, the half-life of BPI-3016 was more than 95h after single dosing in diabetic cynomolgus monkeys. Also, BPI-3016 reduced fasting and post-prandial plasma glucose levels for up to a week after a single dose; It reduced body mass index (BMI), body fat, improved glucose tolerance and showed insulinotropic effects after once-weekly injection for 7 weeks. In conclusion, BPI-3016 retains the effects of GLP-1 with significantly prolonged half-life, making it a promising therapy for type 2 diabetes with once-weekly treatment in the clinic.

Effect of Albiglutide on Cholecystokinin-Induced Gallbladder Emptying in Healthy Individuals: A Randomized Crossover Study.

The glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) exenatide and lixisenatide reduce cholecystokinin (CCK)-induced gallbladder emptying in healthy subjects. It is unknown if all GLP-1 RAs share this effect; therefore, the effect of the GLP-1 RA albiglutide on gallbladder function was assessed. In this randomized, double-blind, 2-way crossover study, a single dose of subcutaneous albiglutide 50 mg or placebo was administered to 17 healthy subjects, and CCK-induced gallbladder contractility was measured by ultrasonography. CCK (0.003 µg/kg) was infused intravenously over 50 minutes on study day 4 (3 days after dosing, to coincide with albiglutide's expected time to maximum concentration). Gallbladder volume, ejection fraction, and the main pancreatic and common bile-duct diameters were measured before, during, and following CCK infusion. Gallbladder volume was significantly greater in the albiglutide vs placebo groups before, during, and after CCK infusion, and the mean difference from placebo increased numerically during CCK infusion. The area under the volume-effect curve was significantly greater with albiglutide (P = .029). Starting at the 30-minute CCK infusion time point, the gallbladder ejection fraction was significantly lower with albiglutide than placebo. Changes in pancreatic duct diameter and common bile-duct diameter were not significantly different between albiglutide and placebo. Similar incidences of adverse events were observed between the albiglutide and placebo treatment periods. No new albiglutide safety signals were detected, and no serious adverse events were reported. In conclusion, similar to other GLP-1 RAs, albiglutide decreased CCK-induced gallbladder emptying compared with placebo in healthy individuals. Clinical implications of the gallbladder effects are unclear at this time.

Lixisenatida en pacientes con diabetes tipo 2 y obesidad: más allá del control glucémico / Lixisenatide in patients with type 2 diabetes and obesity: Beyond glycaemic control

OBJETIVO: Evaluar la tolerancia a lixisenatida y sus efectos sobre el peso y el control metabólico de pacientes con diabetes tipo 2 y obesidad. DISEÑO: Estudio prospectivo. Emplazamiento: Consultas de atención especializada de Endocrinología y Nutrición en Almería, Granada y Málaga. PARTICIPANTES: Pacientes con diabetes tipo 2 y obesidad. INTERVENCIONES: Respuesta y tolerancia al tratamiento con lixisenatida. Mediciones principales: Se analizaron datos clínicos y analíticos con medidas de cambio intrasujeto antes-después del tratamiento. RESULTADOS: Evaluamos 104 pacientes (51% mujeres) con diabetes tipo 2 y obesidad (Almería 18,3%; Granada 40,4%; Málaga 41,3%). Edad media 58,4±10,5 años y duración media de diabetes 11,2±6,7 años. El tiempo medio desde la visita basal a la revisión tras inicio de tratamiento con lixisenatida fue de 3,8±1,6 meses. Encontramos mejoría significativa del peso (p < 0,001), índice de masa corporal (p < 0,001), circunferencia de cintura (p = 0,002), presión arterial sistólica (p < 0,001) y diastólica (p = 0,001), glucemia en ayunas (p < 0,001), HbA1c (p = 0,022), colesterol total (p < 0,001), colesterol LDL (p = 0,046) y triglicéridos (p = 0,020). No se observó alteración de cifras de amilasa en relación con el tratamiento con lixisenatida, y el 7,9% no lo toleraron. CONCLUSIONES: Lixisenatida consigue: 1) mejoría significativa de parámetros antropométricos y control glucémico (glucemia basal y HbA1c); 2) descenso significativo de la presión arterial y del perfil lipídico, y 3) seguridad y buena tolerancia en la mayoría de los pacientes. Además, encontramos una significativa intensificación del tratamiento antihipertensivo e hipolipemiante

AIM: To evaluate tolerance to lixisenatide and its effects on weight and metabolic control in type 2 diabetes and obese patients. DESIGN: Prospective study. SETTING: Endocrinology clinics in Almeria, Granada and Malaga. PARTICIPANTS: Patients with type 2 diabetes and obesity. INTERVENTIONS: Response and tolerance to lixisenatide treatment. MAIN MEASUREMENTS: Clinical and analytical data of the subjects were evaluated at baseline and after treatment. RESULTS: The study included 104 patients (51% women) with type 2 diabetes and obesity (Almeria 18.3%; Granada 40.4%; Malaga 41.3%). The mean age was 58.4±10.5 years, and the mean duration of diabetes was 11.2±6.7 years. The patients were re-evaluated at 3.8±1.6 months after treatment with lixisenatide. Significant improvements were found in weight (P<.001), body mass index (P<.001), waist circumference (P=.002), systolic blood pressure (P<.001), diastolic blood pressure (P=.001), fasting glucose (P<.001), HbA1c (P=.022), Total cholesterol (P<.001), LDL-cholesterol (P=.046), triglycerides (P=.020), hypertension drugs (P<.001), and lipids drugs (P<.001). No changes were observed in levels of amylase related to lixisenatide treatment, and 7.9% of patients did not tolerate it. CONCLUSIONS: Lixisenatide achieved significant improvements in anthropometric parameters, glycaemic control (fasting glucose and HbA1c), blood pressure and lipids. It was safe and well tolerated in most patients. In addition, there was a significant increase in the use of antihypertensive and lipid-lowering therapy

Pancreas and liver uptake of new radiolabeled incretins (GLP-1 and Exendin-4) in models of diet-induced and diet-restricted obesity.

INTRODUCTION: Radiolabeled GLP-1 and its analog Exendin-4, have been employed in diabetes and insulinoma. No protocol in conventional Diet-Induced Obesity (DIO), and Diet-Restricted Obesity (DRO), has been identified. Aiming to assess pancreatic beta cell uptake in DIO and DRO, a protocol was designed. METHODS: GLP-1-ßAla-HYNIC and HYNIC-ßAla-Exendin-4 were labeled with technetium-99m. Four Swiss mouse models were adopted: Controls (C), Alloxan Diabetes Controls (ADC), DIO and DRO. Biodistribution and ex-vivo planar imaging were documented. RESULTS: Radiolabeling yield was in the range of 97% and both agents were hydrophilic. Fasting Blood Glucose (FBG) was 79.2±8.2mg/dl in C, 590.4±23.3mg/dl in ADC, 234.3±66.7mg/dl in DIO, and 96.6±9.3 in DRO (p=0.010). Biodistribution confirmed predominantly urinary excretion. DIO mice exhibited depressed uptake in liver and pancreas, for both radiomarkers, in the range of ADC. DRO only partially restored such values. 99mTc-HYNIC-ßAla-Exendin-4 demonstrated better results than GLP-1-ßAla-HYNIC-99mTc. CONCLUSIONS: 1) Diet-induced obesity remarkably depressed beta cell uptake; 2) Restriction of obesity failed to normalize uptake, despite robust improvement of FBG; 3) HYNIC-ßAla-Exendin-4 was the most useful marker; 4) Further studies are recommended in obesity and dieting, including bariatric surgery.

Clinical Pharmacokinetics and Pharmacodynamics of Albiglutide.

Albiglutide is a long-acting, glucagon-like peptide-1 receptor agonist for subcutaneous administration with a recommended dose of 30-50 mg once weekly. The aim of this article is to outline the pharmacokinetic and pharmacodynamic properties of albiglutide including the clinical efficacy and safety data underlying the approval of albiglutide for the treatment of type 2 diabetes mellitus in both Europe and USA. Albiglutide is cleared from the circulation (by a mechanism partially dependent on renal function) with an elimination half-life of 5 days, allowing once-weekly administration. In the clinical trial program called HARMONY, albiglutide demonstrated placebo-corrected reductions in glycosylated hemoglobin of 0.8-1.0%. In addition, reductions in fasting plasma glucose in the range of 1.3-2.4 mmol/L compared with placebo were reported. Albiglutide caused weight reductions at a level comparable to placebo in the HARMONY trials, possibly related to limited central nervous system penetration of the large albiglutide molecule. Albiglutide demonstrated a generally favorable safety profile, although with a signal of an increased risk of pancreatitis. The well-known adverse events related to glucagon-like peptide-1 receptor activation such as nausea, diarrhea, and vomiting were less frequent with albiglutide compared with another glucagon-like peptide-1 receptor agonist, liraglutide, but slightly more frequent following treatment with albiglutide than with placebo or active comparators from other classes of anti-hyperglycemic drugs. The full risk-benefit profile for albiglutide used in treating type 2 diabetes will not be clear until reporting of the long-term cardiovascular outcome trial (HARMONY Outcome) with planned completion in 2019.