Elucidating the Mechanism of Absorption of Fast-Acting Insulin Aspart: The Role of Niacinamide.

PURPOSE: Fast-acting insulin aspart (faster aspart) is a novel formulation of insulin aspart containing two additional excipients: niacinamide, to increase early absorption, and L-arginine, to optimize stability. The aim of this study was to evaluate the impact of niacinamide on insulin aspart absorption and to investigate the mechanism of action underlying the accelerated absorption. METHODS: The impact of niacinamide was assessed in pharmacokinetic analyses in pigs and humans, small angle X-ray scattering experiments, trans-endothelial transport assays, vascular tension measurements, and subcutaneous blood flow imaging. RESULTS: Niacinamide increased the rate of early insulin aspart absorption in pigs, and pharmacokinetic modelling revealed this effect to be most pronounced up to ~30-40 min after injection in humans. Niacinamide increased the relative monomer fraction of insulin aspart by ~35%, and the apparent permeability of insulin aspart across an endothelial cell barrier by ~27%. Niacinamide also induced a concentration-dependent vasorelaxation of porcine arteries, and increased skin perfusion in pigs. CONCLUSION: Niacinamide mediates the acceleration of initial insulin aspart absorption, and the mechanism of action appears to be multifaceted. Niacinamide increases the initial abundance of insulin aspart monomers and transport of insulin aspart after subcutaneous administration, and also mediates a transient, local vasodilatory effect.

Enhanced disulphide bond stability contributes to the once-weekly profile of insulin icodec.

Insulin icodec is a once-weekly insulin analogue that has a long half-life of approximately 7 days, making it suitable for once weekly dosing. The Insulin icodec molecule was developed based on the hypothesis that lowering insulin receptor affinity and introducing a strong albumin-binding moiety would result in a long insulin half-life, provided that non-receptor-mediated clearance is diminished. Here, we report an insulin clearance mechanism, resulting in the splitting of insulin molecules into its A-chain and B-chain by a thiol-disulphide exchange reaction. Even though the substitutions in insulin icodec significantly stabilise insulin against such degradation, some free B-chain is observed in plasma samples from minipigs and people with type 2 diabetes. In summary, we identify thiol-disulphide exchange reactions to be an important insulin clearance mechanism and find that stabilising insulin icodec towards this reaction significantly contributes to its long pharmacokinetic/pharmacodynamic profile.

Probing the mechanism of reduced in vivo potency of insulin detemir.

BACKGROUND: Insulin detemir (IDet) is an insulin analog used to treat diabetes. IDet shows full efficacy but reduced potency compared to human insulin (HI) in both man and rat. In contrast, in pigs and dogs, IDet appears to have full in vivo potency. Non-receptor mediated degradation (NRMD) has previously been suggested as an explanation for the low potency of IDet, but this hypothesis has not been investigated further until now. Bacitracin is a nonspecific protease inhibitor which we hypothesized could inhibit NRMD of IDet in rats. RESEARCH DESIGN AND METHODS: Healthy male rats instrumented with permanent catheters underwent euglycemic clamp during constant infusion of either HI or IDet at effect-matched doses with co-infusion of vehicle or bacitracin. RESULTS: Plasma concentrations of IDet increased significantly (p < 0.005) during bacitracin compared to vehicle co-infusion and the concomitant increase in glucose infusion rate (GIR, p < 0.001) required to maintain euglycemic clamp indicates that the IDet rescued from NRMD indeed was active. No significant differences were detected with co-infusions of HI with either bacitracin or vehicle. CONCLUSIONS: A large proportion of NRMD of IDet which can be inhibited by bacitracin may partly explain the reduced potency of IDet observed in rats and likely also in man.

Factors Affecting Performance of Insulin Pen Injector Technology: A Narrative Review.

BACKGROUND: Insulin treatment is an essential hormone replacement therapy for the survival of people with type 1 diabetes and is often used for treatment in type 2 diabetes, particularly as the disease progresses. Advances in insulin therapy have been made since its discovery, including production of human insulin and development of insulin analogs with improved efficacy and safety profiles. The different types of available insulin formulations allow health care professionals to personalize treatment to an individual's needs. Generally, insulin requires parenteral administration via subcutaneous injection owing to very low oral bioavailability. METHODS: This article reviews the human, technological, economical, and regulatory factors affecting the performance of insulin pens and the relationship between them. Opportunities and challenges that insulin pen injections may encounter in the future are also considered. RESULTS: Insulin delivery devices, together with other factors, influence dose accuracy, convenience, and quality of life, contributing to easier medication administration with high efficacy and safety. For patients, ease of use, fast and accurate drug delivery, and painless injection are the most valuable features of an insulin injection device. For manufacturers, technological feasibility and economic viability also need to be considered when developing injection devices. CONCLUSION: Insulin pen injectors are generally preferred over vial and syringe, although access may be limited in some health care systems. Insulin pen injectors can adapt to different insulin regimens and formulations and have the potential to acquire dosing data in real time.

Continuous Glucose Monitoring Sensor Glucose Levels and Insulin Pump Infusion Set Wear-Time During Treatment with Fast-Acting Insulin Aspart: A Post Hoc Analysis of Onset 5.

Background: In the onset 5 trial, fast-acting insulin aspart (faster aspart) was noninferior to insulin aspart (IAsp) for change from baseline glycated hemoglobin at 16 weeks, when used in continuous subcutaneous insulin infusion by participants with type 1 diabetes. The aim of this post hoc analysis was to investigate whether infusion set wear-time was associated with changes in sensor glucose, measured using continuous glucose monitoring (CGM). Materials and Methods: This was a post hoc analysis of onset 5 data. Mean infusion set wear-time and duration of CGM-wearing period were assessed. Mean CGM sensor glucose 24 h before and 24 h after were used to calculate the before-after difference (CGM sensor glucose drift). Results: Mean infusion set wear-time was 2.9 and 3.0 days in the faster aspart and IAsp arms, respectively. At 16 weeks, the average duration of the CGM wearing period was 13.7 and 13.8 days, respectively. Mean CGM sensor glucose before versus after an infusion set change, at week 16, was 10.14 versus 9.39 mmol/L with faster aspart and 9.48 versus 9.47 mmol/L with IAsp. The estimated treatment difference in CGM sensor glucose drift at 16 weeks for faster aspart versus IAsp was +0.72 mmol/L (95% confidence interval: 0.48-0.96, P < 0.001). Conclusions: Mean infusion set wear-time and duration of CGM-wearing period were similar for faster aspart and IAsp. A significantly greater upward drift in CGM sensor glucose values measured during an infusion set wearing period was observed with faster aspart versus IAsp. Clinical trial registration: NCT02825251.

Commemorating insulin's centennial: engineering insulin pharmacology towards physiology.

The life-saving discovery of insulin in Toronto in 1921 is one of the most impactful achievements in medical history, at the time being hailed as a miracle treatment for diabetes. The insulin molecule itself, however, is poorly amenable as a pharmacological intervention, and the formidable challenge of optimizing insulin therapy has been ongoing for a century. We review early academic insights into insulin structure and its relation to self-association and receptor binding, as well as recombinant biotechnology, which have all been seminal for drug design. Recent developments have focused on combining genetic and chemical engineering with pharmaceutical optimization to generate ultra-rapid and ultra-long-acting, tissue-selective, or orally delivered insulin analogs. We further discuss these developments and propose that future scientific efforts in molecular engineering include realizing the dream of glucose-responsive insulin delivery.

Fast-acting insulin aspart (Fiasp®) improves glycemic outcomes when used with MiniMedTM 670G hybrid closed-loop system in simulated trials compared to NovoLog®.

INTRODUCTION: Medtronic has developed a virtual patient simulator for modeling and predicting insulin therapy outcomes for people with type 1 diabetes (T1D). An enhanced simulator was created to estimate outcomes when using the MiniMedTM 670G system with standard NovoLog® (EU: NovoRapid, US: NovoLog) versus Fiasp ® by using clinical data. METHODS: Sixty-seven participants' PK profiles were generated per type of insulin (Total of 134 PK profiles). 7,485 virtual patients' PK measurements was matched with one of the 67 NovoLog® PK Tmax values. These 7,485 virtual patients were then simulated using the Medtronic MiniMed™ 670G algorithm following an in-silico protocol of 90 days: 14 days in open loop (Manual Mode) followed by 76 days in closed loop (Auto Mode). Simulation study was repeated with each NovoLog® PK profile being replaced by its corresponding Fiasp® PK profile in the same virtual patient. To validate our in-silico analysis, we compared the results of "actual" 19 "real life" patients from a clinical study RESULTS: Simulated overall and postprandial glycemic outcomes improved in all age groups with Fiasp®. The percentage of time in the euglycemic range increased by about ~2.2% with Fiasp®, in all age groups (p < 0.01). The percentage of time spent at <70 mg/dL was reduced by about ~0.6% with insulin Fiasp® (p < 0.01) and the mean glucose was reduced by about 1.3 mg/dL (p < 0.01), excluding those age <7 years. The simulated mean postprandial SG was reduced by ~5 mg/dL, a significant difference for all age groups. A clinical study results showed similar improvements with MiniMedTM 670G system when switching from NovoLog® to Fiasp®. CONCLUSIONS: The simulation studies indicate that using Fiasp® in place of NovoLog® with the MiniMedTM 670G system will significantly improve the time spent in the healthy, euglycemic range and reduce exposure to hyperglycemia and hypoglycemia in most patients.

A novel high-affinity peptide antagonist to the insulin receptor.

In this publication we describe a peptide insulin receptor antagonist, S661, which is a single chain peptide of 43 amino acids. The affinity of S661 for the insulin receptor is comparable to that of insulin and the selectivity for the insulin receptor versus the IGF-1 receptor is higher than that of insulin itself. S661 is also an antagonist of the insulin receptor of other species such as pig and rat, and it also has considerable affinity for hybrid insulin/IGF-1 receptors. S661 completely inhibits insulin action, both in cellular assays and in vivo in rats. A biosynthetic version called S961 which is identical to S661 except for being a C-terminal acid seems to have properties indistinguishable from those of S661. These antagonists provide a useful research tool for unraveling biochemical mechanisms involving the insulin receptor and could form the basis for treatment of hypoglycemic conditions.

Improved beta-cell survival and reduced insulitis in a type 1 diabetic rat model after treatment with a beta-cell-selective K(ATP) channel opener.

Treatment with ATP-sensitive K(+) channel openers (KCOs) leads to inhibition of insulin secretion and metabolic "rest" in beta-cells. It is hypothesized that in type 1 diabetes this may reduce beta-cell death resulting from metabolic stress as well as reduce the immunogenicity of the beta-cells during autoimmune beta-cell destruction. We have investigated whether the beta-cell-selective KCO compound, NN414, can be used to improve beta-cell survival in DR-BB rats rendered diabetic by modulation of their immune system. The rats were treated three times daily on days 1-19 with NN414, diazoxide, or vehicle. On day 21, an intravenous glucose tolerance test was conducted to assess beta-cell function. Postmortem histological analysis of rats' pancreata assessed the degree of insulitis and beta-cell volume. Among NN414-treated rats, 46% (16 of 35) were found to have a beta-cell mass similar to that of nondiabetic controls and significant glucose-stimulated C-peptide values, whereas only 11% (4 of 36) of vehicle-treated rats possessed a normal beta-cell mass and function (P < 0.002, by chi(2) test). Furthermore, responsive NN414-treated rats were almost free of insulitis. Thus, this study demonstrated that treatment with KCO compounds can indeed lead to preservation of beta-cell function and reduction of insulitis in a rat diabetes model.

NN414, a SUR1/Kir6.2-selective potassium channel opener, reduces blood glucose and improves glucose tolerance in the VDF Zucker rat.

A novel potassium channel opener compound, NN414, selective for the SUR1/Kir6.2 subtype of the ATP-sensitive potassium channel, was used to examine the effect of reducing beta-cell workload in the male Vancouver diabetic fatty (VDF) Zucker rat model of mild type 2 diabetes. Two chronic dosing protocols of NN414 of 3 weeks' duration were compared with appropriate vehicle-treated controls. In the first group, rats received NN414 (continued group; 1.5 mg/kg p.o. twice daily), during which an oral glucose tolerance test (OGTT) (on day 19 of dosing) was performed and insulin secretion from an in situ perfused pancreas preparation (on day 21) was measured. The second group received NN414 (discontinued group; same dose), but active treatment was replaced by vehicle treatment 2 days before the OGTT and for a further 2 days before the perfused pancreas study. Basal glucose was significantly reduced by NN414, with the fall averaging 0.64 mmol/l after 3 weeks of treatment (P < 0.0001). The glucose excursion and hyperinsulinemia during the OGTT were significantly different between the continued, discontinued, and vehicle groups (glucose area under the curve [AUC]: 640 +/- 29, 740 +/- 27, and 954 +/- 82 mmol. l(-1). min(-1), respectively, P < 0.0001; insulin AUC: 38.9 +/- 4.2, 44.2 +/- 4.2, and 55.1 +/- 2.6 nmol.l(-1).min(-1), respectively, P < 0.0001). Hyperinsulinemia during the pancreas perfusion with 4.4 mmol/l glucose was significantly reduced in both treatment groups versus vehicle (P < 0.0005). Insulin secretory responsiveness to a step increase in glucose from 4.4 to 16.6 mmol/l, calculated relative to basal, was significantly improved in the continued group versus vehicle (P < 0.01). In conclusion, administration of NN414 for 3 weeks in VDF rats reduces basal hyperglycemia, improves glucose tolerance, and reduces hyperinsulinemia during an OGTT and improves insulin secretory responsiveness ex vivo. NN414 may therefore represent a novel approach to the prevention and treatment of impaired glucose tolerance and type 2 diabetes.

Bedtime administration of NN2211, a long-acting GLP-1 derivative, substantially reduces fasting and postprandial glycemia in type 2 diabetes.

Glucagon-like peptide 1 (GLP-1) is a potent glucose-lowering agent of potential interest for the treatment of type 2 diabetes. To evaluate actions of NN2211, a long-acting GLP-1 derivative, we examined 11 patients with type 2 diabetes, age 59 +/- 7 years (mean +/- SD), BMI 28.9 +/- 3.0 kg/m(2), HbA(1c) 6.5 +/- 0.6%, in a double-blind, placebo-controlled, crossover design. A single injection (10 microg/kg) of NN2211 was administered at 2300 h, and profiles of circulating insulin, C-peptide, glucose, and glucagon were monitored during the next 16.5 h. A standardized mixed meal was served at 1130 h. Efficacy analyses were performed for the fasting (7-8 h) and mealtime (1130-1530 h) periods. Insulin secretory rates (ISR) were estimated by C-peptide deconvolution analysis. Glucose pulse entrainment (6 mg x kg(-1) x min(-1) every 10 min) was evaluated by 1-min sampled measurements of insulin concentrations from 0930 to 1030 h and subsequent time series analysis of the insulin concentration profiles. All results are given as NN2211 versus placebo; statistical analyses were performed by analysis of variance. In the fasting state, plasma glucose was significantly reduced (6.9 +/- 1.0 vs. 8.1 +/- 1.0 mmol/l; P = 0.004), ISR was increased (179 +/- 70 vs. 163 +/- 66 pmol/min; P = 0.03), and plasma glucagon was unaltered (19 +/- 4 vs. 20 +/- 4 pg/ml; P = 0.17) by NN2211. Meal-related area under the curve (AUC)(1130-1530 h) for glucose was markedly reduced (30.6 +/- 2.4 vs. 39.9 +/- 7.3 mmol x l(-1) x h(-1); P < 0.001), ISR AUC(1130-1530 h) was unchanged (118 +/- 32 vs. 106 +/- 27 nmol; P = 0.13), but the increment (relative to premeal values) was increased (65 +/- 22 vs. 45 +/- 11 nmol; P = 0.04). Glucagon AUC(1130-1530 h) was suppressed (77 +/- 18 vs. 82 +/- 17 pmol x l(-1) x h(-1); P = 0.04). Gastric emptying was significantly delayed as assessed by AUC(1130-1530 h) of 3-ortho-methylglucose (400 +/- 84 vs. 440 +/- 70 mg x l(-1) x h(-1); P = 0.02). During pulse entrainment, there was a tendency to increased high frequency regularity of insulin release as measured by a greater spectral power and autocorrelation coefficient (0.05 < P < 0.10). The pharmacokinetic profile of NN2211, as assessed by blood samplings for up to 63 h postdosing, was as follows: T(1/2) = 10.0 +/- 3.5 h and T(max) = 12.4 +/- 1.7 h. Two patients experienced gastrointestinal side effects on the day of active treatment. In conclusion, the long-acting GLP-1 derivative NN2211 effectively reduces fasting as well as meal-related (approximately 12 h postadministration) glycemia by modifying insulin secretion, delaying gastric emptying, and suppressing prandial glucagon secretion.

One week's treatment with the long-acting glucagon-like peptide 1 derivative liraglutide (NN2211) markedly improves 24-h glycemia and alpha- and beta-cell function and reduces endogenous glucose release in patients with type 2 diabetes.

Glucagon-like peptide 1 (GLP-1) is potentially a very attractive agent for treating type 2 diabetes. We explored the effect of short-term (1 week) treatment with a GLP-1 derivative, liraglutide (NN2211), on 24-h dynamics in glycemia and circulating free fatty acids, islet cell hormone profiles, and gastric emptying during meals using acetaminophen. Furthermore, fasting endogenous glucose release and gluconeogenesis (3-(3)H-glucose infusion and (2)H(2)O ingestion, respectively) were determined, and aspects of pancreatic islet cell function were elucidated on the subsequent day using homeostasis model assessment and first- and second-phase insulin response during a hyperglycemic clamp (plasma glucose approximately 16 mmol/l), and, finally, on top of hyperglycemia, an arginine stimulation test was performed. For accomplishing this, 13 patients with type 2 diabetes were examined in a double-blind, placebo-controlled crossover design. Liraglutide (6 micro g/kg) was administered subcutaneously once daily. Liraglutide significantly reduced the 24-h area under the curve for glucose (P = 0.01) and glucagon (P = 0.04), whereas the area under the curve for circulating free fatty acids was unaltered. Twenty-four-hour insulin secretion rates as assessed by deconvolution of serum C-peptide concentrations were unchanged, indicating a relative increase. Gastric emptying was not influenced at the dose of liraglutide used. Fasting endogenous glucose release was decreased (P = 0.04) as a result of a reduced glycogenolysis (P = 0.01), whereas gluconeogenesis was unaltered. First-phase insulin response and the insulin response to an arginine stimulation test with the presence of hyperglycemia were markedly increased (P < 0.001), whereas the proinsulin/insulin ratio fell (P = 0.001). The disposition index (peak insulin concentration after intravenous bolus of glucose multiplied by insulin sensitivity as assessed by homeostasis model assessment) almost doubled during liraglutide treatment (P < 0.01). Both during hyperglycemia per se and after arginine exposure, the glucagon responses were reduced during liraglutide administration (P < 0.01 and P = 0.01). Thus, 1 week's treatment with a single daily dose of the GLP-1 derivative liraglutide, operating through several different mechanisms including an ameliorated pancreatic islet cell function in individuals with type 2 diabetes, improves glycemic control throughout 24 h of daily living, i.e., prandial and nocturnal periods. This study further emphasizes GLP-1 and its derivatives as a promising novel concept for treatment of type 2 diabetes.

Glucose- and interleukin-1beta-induced beta-cell apoptosis requires Ca2+ influx and extracellular signal-regulated kinase (ERK) 1/2 activation and is prevented by a sulfonylurea receptor 1/inwardly rectifying K+ channel 6.2 (SUR/Kir6.2) selective potassium channel opener in human islets.

Increasing evidence indicates that a progressive decrease in the functional beta-cell mass is the hallmark of both type 1 and type 2 diabetes. The underlying causes, beta-cell apoptosis and impaired secretory function, seem to be partly mediated by macrophage production of interleukin (IL)-1beta and/or high-glucose-induced beta-cell production of IL-1beta. Treatment of type 1 and type 2 diabetic patients with the potassium channel opener diazoxide partially restores insulin secretion. Therefore, we studied the effect of diazoxide and of the novel potassium channel opener NN414, selective for the beta-cell potassium channel SUR1/Kir6.2, on glucose- and IL-1beta-induced apoptosis and impaired function in human beta-cells. Exposure of human islets for 4 days to 11.1 and 33.3 mmol/l glucose, 2 ng/ml IL-1beta, or 10 and 100 micromol/l of the sulfonylurea tolbutamide induced beta-cell apoptosis and impaired glucose-stimulated insulin secretion. The deleterious effects of glucose and IL-1beta were blocked by 200 micromol/l diazoxide as well as by 3 and 30 micromol/l NN414. By Western blotting with phosphospecific antibodies, glucose and IL-1beta were shown to activate the extracellular signal-regulated kinase (ERK) 1/2, an effect that was abrogated by 3 micromol/l NN414. Similarly, 1 micromol/l of the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor PD098059 or 1 micromol/l of the l-type Ca(2+) channel blocker nimodipine prevented glucose- and IL-1beta-induced ERK activation, beta-cell apoptosis, and impaired function. Finally, islet release of IL-1beta in response to high glucose could be abrogated by nimodipine, NN414, or PD098059. Thus, in human islets, glucose- and IL-1beta-induced beta-cell secretory dysfunction and apoptosis are Ca(2+) influx and ERK dependent and can be prevented by the beta-cell selective potassium channel opener NN414.

The GLP-1 derivative NN2211 restores beta-cell sensitivity to glucose in type 2 diabetic patients after a single dose.

Glucagon-like peptide 1 (GLP-1) stimulates insulin secretion in a glucose-dependent manner, but its short half-life limits its therapeutic potential. We tested NN2211, a long-acting GLP-1 derivative, in 10 subjects with type 2 diabetes (means +/- SD: age 63 +/- 8 years, BMI 30.1 +/- 4.2 kg/m(2), HbA(1c) 6.5 +/- 0.8%) in a randomized, double-blind, placebo-controlled, crossover study. A single injection (7.5 micro g/kg) of NN2211 or placebo was administered 9 h before the study. beta-cell sensitivity was assessed by a graded glucose infusion protocol, with glucose levels matched over the 5-12 mmol/l range. Insulin secretion rates (ISRs) were estimated by deconvolution of C-peptide levels. Findings were compared with those in 10 nondiabetic volunteers during the same glucose infusion protocol. In type 2 diabetic subjects, NN2211, in comparison with placebo, increased insulin and C-peptide levels, the ISR area under the curve (AUC) (1,130 +/- 150 vs. 668 +/- 106 pmol/kg; P < 0.001), and the slope of ISR versus plasma glucose (1.26 +/- 0.36 vs. 0.54 +/- 0.18 pmol x l[min(-1) x mmol(-1) x kg(-1)]; P < 0.014), with values similar to those of nondiabetic control subjects (ISR AUC 1,206 +/- 99; slope of ISR versus plasma glucose, 1.44 +/- 0.18). The long-acting GLP-1 derivative, NN2211, restored beta-cell responsiveness to physiological hyperglycemia in type 2 diabetic subjects.

Pharmacokinetics, pharmacodynamics, safety, and tolerability of a single-dose of NN2211, a long-acting glucagon-like peptide 1 derivative, in healthy male subjects.

OBJECTIVE: The primary objective of the present study was to investigate the safety, tolerability, and pharmacokinetics of a single dose of NN2211, a long-acting glucagon-like peptide 1 (GLP-1) derivative, in healthy male subjects. The secondary objective was to investigate the pharmacodynamics of NN2211. RESEARCH DESIGN AND METHODS: In a double-blind, randomized dose, escalation, placebo-controlled study, healthy male subjects were enrolled at eight consecutive dose levels (1.25, 2.5, 5.0, 10.0, 12.5, 15.0, 17.5, and 20.0 microg/kg) with eight subjects per dose level at a 3:1 active:placebo randomization. After subcutaneous dosing with NN2211, 48-h pharmacokinetic, and 24-h glucose, insulin and glucagon profiles were assessed. In addition, three subjects at each dose level were randomly assigned (one placebo/two active) to an intravenous glucose tolerance test (IVGTT) 9 h after the dose (corresponding to the time to maximal plasma concentration of NN2211). RESULTS: After subcutaneous administration, the half-life of NN2211 was found to be 11-15 h. Overall, although there were no statistically significant differences compared with placebo in the area under the curve (0-9 h for insulin or glucagon), there was a borderline- significant lowering of glucose levels (P = 0.066). During the IVGTT, there was a statistically significant increase in insulin secretion (P = 0.0002), but there was no significant effect on glucagon levels. Although no significant effect was observed on glucose levels during the IVGTT, there was a dose-dependent increase in the glucose disappearance constant. Whereas no serious adverse events were observed, there was a higher incidence of adverse events after active treatment compared with placebo treatment (notably headache, dizziness, nausea, and vomiting). CONCLUSIONS: This study provides evidence that NN2211 has a pharmacokinetic profile consistent with once-daily dosing in humans.

Novel tricyclic-alpha-alkyloxyphenylpropionic acids: dual PPARalpha/gamma agonists with hypolipidemic and antidiabetic activity.

Synthesis and structure-activity relationships of tricyclic alpha-ethoxy-phenylpropionic acid derivatives guided by in vitro PPARalpha and PPARgamma transactivation data and computer modeling led to the identification of the novel carbazole analogue, 3q, with dual PPARalpha (EC(50) = 0.36 microM) and PPARgamma (EC(50) = 0.17 microM) activity in vitro. Ten days treatment of db/db mice with 3q improved the insulin sensitivity, as measured by OGTT, better than that seen with both pioglitazone and rosiglitazone treatment, suggesting in vivo PPARgamma activity. Likewise, 3q lowered plasma triglycerides and cholesterol in high cholesterol fed rats after 4 days treatment, indicating in vivo PPARalpha activity. Investigations of the pharmacokinetics of selected compounds suggested that extended drug exposure improved the in vivo activity of in vitro active compounds.

GLP-1 derivative liraglutide in rats with beta-cell deficiencies: influence of metabolic state on beta-cell mass dynamics.

(1) Liraglutide is a long-acting GLP-1 derivative, designed for once daily administration in type II diabetic patients. To investigate the effects of liraglutide on glycemic control and beta-cell mass in rat models of beta-cell deficiencies, studies were performed in male Zucker diabetic fatty (ZDF) rats and in 60% pancreatectomized rats. (2) When liraglutide was dosed s.c. at 150 microg kg-1 b.i.d. for 6 weeks in ZDF rats 6-8 weeks of age at study start, diabetes development was markedly attenuated. Blood glucose was approximately 12 mm lower compared to vehicle (P<0.0002), and plasma insulin was 2-3-fold higher during a normal 24-h feeding period (P<0.001). Judged by pair feeding, approximately 53% of the antihyperglycemic effect observed on 24-h glucose profiles was mediated by a reduction in food intake, which persisted throughout the study and averaged 16% (P<0.02). (3) Histological analyses revealed that beta-cell mass and proliferation were significantly lower in prediabetic animals still normoglycemic after 2 weeks treatment compared to vehicle-treated animals that had begun to develop diabetes. When the treatment period was 6 weeks, the liraglutide-treated animals were no longer completely normoglycemic and the beta-cell mass was significantly increased compared to overtly diabetic vehicle-treated animals, while beta-cell proliferation was unaffected. (4) In the experiments with 60% pancreatectomized rats, 8 days treatment with liraglutide resulted in a significantly lower glucose excursion in response to oral glucose compared to vehicle treatment. Again, part of the antihyperglycemic effect was due to reduced food intake. No effect of liraglutide on beta-cell mass was observed in these virtually normoglycemic animals. (5) In conclusion, treatment with liraglutide has marked antihyperglycemic effects in rodent models of beta-cell deficiencies, and the in vivo effect of liraglutide on beta-cell mass may in part depend on the metabolic state of the animals.

Attenuation of hyperinsulinemia by NN414, a SUR1/Kir6.2 selective K-adenosine triphosphate channel opener, improves glucose tolerance and lipid profile in obese Zucker rats.

Chronic attenuation of hyperinsulinemia by diazoxide (DZ), a K-adenosine triphosphate (ATP) channel opener and an inhibitor of glucose-mediated insulin secretion, improved glucose tolerance and lipid profile and decreased the rate of weight gain in obese Zucker rats. To determine whether suppression of hyperinsulinemia alters daily food consumption, rate of weight gain, glucose tolerance, and lipid profile, we compared the effects of NN414, a potent and SUR1/Kir6.2 selective K(atp)() channel opener, with DZ in obese and lean Zucker rats. DZ (150 mg/kg/d), low-dose (LDNN414: 10 mg/kg/d), high-dose (HDNN414: 30 mg/kg/d), and vehicle (C) were administered to 7-week-old obese and lean female Zucker rats for a period of 6 weeks. Each animal underwent an intraperitoneal glucose tolerance test (IPGTT) at the end of study period. While NN414 treatment did not affect food intake and rate of weight gain in any of the strains, DZ treatment reduced food intake (P <.001) and rate of weight gain (P <.001) in obese rats. The fasting plasma insulin levels and area under the curve (AUC) insulin response to IPGTT were significantly attenuated in LDNN414 (P <.05), HDNN414 (P <.01), and DZ (P <.01) obese and lean rats compared with their controls. This was accompanied by a significant reduction in AUC glucose only in LDNN414 (P <.05), HDNN414 (P <.01), and DZ (P <.01) obese rats compared with controls. While hemoglobin A(1c) (HbA(1c)) was not affected in LDNN414 obese rats, it was higher in HDNN414 obese animals (P <.001), LD-, HDNN414 (P <.001), and DZ (P <.005) lean rats compared with their respective controls. DZ obese rats showed lower HbA(1c) levels than C obese rats (P <.02). The plasma free fatty acid (FFA) levels were only decreased in HDNN414 (P <.05) and DZ (P <.002) obese rats, whereas plasma triglyceride (TG) levels were decreased in LDNN414 (P <.05), HDNN414 (P <.001), and DZ (P <.001) obese rats compared with controls. Finally, plasma leptin level was only decreased in DZ obese rats compared with controls (P <.001). The new SUR1/Kir6.2 selective K(atp)() channel opener, NN414, reduced hyperinsulinemia in a dose-dependent manner without a significant effect on food consumption and rate of weight gain. NN414-induced beta-cell rest in obese rats was associated with a significant improvement in glucose responsiveness, suggesting an increase in insulin sensitivity after its withdrawal. There was an overall deterioration in glycemic control at the high dose as measured by HbA(1c). There was a dose-dependent improvement in lipid profiles of obese Zucker rats. These results suggest that pharmacologic attenuation of hyperinsulinemic state by low-dose NN414 may be therapeutically beneficial in insulin-resistant states without any deterioration in overall glycemic control.

NN2211: a long-acting glucagon-like peptide-1 derivative with anti-diabetic effects in glucose-intolerant pigs.

Glucagon-like peptide-1 (GLP-1) is an effective anti-diabetic agent, but its metabolic instability makes it therapeutically unsuitable. This study investigated the pharmacodynamics of a long-acting GLP-1 derivative (NN2211: (Arg(34)Lys(26)-(N- epsilon -(gamma-Glu(N-alpha-hexadecanoyl)))-GLP-1(7-37)), after acute and chronic treatment in hyperglycaemic minipigs. During hyperglycaemic glucose clamps, NN2211 (2 micrograms kg(-1) i.v.) treated pigs required more (P < 0.005) glucose than control animals (5.8 +/- 2.1 vs. 2.9 +/- 1.8 mg kg(-1) min(-1)). Insulin excursions were higher (P < 0.01) after NN2211 (15,367 +/- 5,438 vs. 9,014 +/- 2,952 pmol l(-1) min), and glucagon levels were suppressed (P < 0.05). Once-daily injections of NN2211 (3.3 micrograms kg(-1) s.c.) reduced the glucose excursion during an oral glucose tolerance test, to 59 +/- 15% of pre-treatment values by 4 weeks (P < 0.05), without measurable changes in insulin responses. Fructosamine concentrations were unaltered by vehicle, but decreased (from 366 +/- 187 to 302 +/- 114 micromol l(-1), P = 0.14) after 4 weeks of NN2211. Gastric emptying was reduced (P < 0.05) by NN2211. NN2211 acutely increases glucose utilization during a hyperglycaemic glucose clamp and chronic treatment results in better daily metabolic control. Therefore, NN2211, a GLP-1 derivative that can be administered once daily, holds promise as a new anti-diabetic drug with a minimal risk of hypoglycaemia.

Phase-locking regions in a forced model of slow insulin and glucose oscillations.

We present a detailed numerical investigation of the phase-locking regions in a forced model of slow oscillations in human insulin secretion and blood glucose concentration. The bifurcation structures of period 2pi and 4pi tongues are mapped out and found to be qualitatively identical to those of several other periodically forced self-oscillating systems operating across a Hopf-bifurcation point. The numerical analyses are supplemented by clinical experiments. (c) 1995 American Institute of Physics.