Liraglutide: a review of its use in adult patients with type 2 diabetes mellitus

Legume-Derived Bioactive Peptides in Type 2 Diabetes: Opportunities and Challenges

Diabetes mellitus is a complex disorder characterized by insufficient insulin production or insulin resistance, which results in a lifelong dependence on glucose-lowering drugs for almost all patients. During the fight with diabetes, researchers are always thinking about what characteristics the ideal hypoglycemic drugs should have. From the point of view of the drugs, they should maintain effective control of blood sugar, have a very low risk of hypoglycemia, not increase or decrease body weight, improve β-cell function, and delay disease progression. Recently, the advent of oral peptide drugs, such as semaglutide, brings exciting hope to patients with chronic diabetes. Legumes, as an excellent source of protein, peptides, and phytochemicals, have played significant roles in human health throughout human history. Some legume-derived peptides with encouraging anti-diabetic potential have been gradually reported over the last two decades. Their hypoglycemic mechanisms have also been clarified at some classic diabetes treatment targets, such as the insulin receptor signaling pathway or other related pathways involved in the progress of diabetes, and key enzymes including α-amylase, α-glucosidase, and dipeptidyl peptidase-IV (DPP-4). This review summarizes the anti-diabetic activities and mechanisms of peptides from legumes and discusses the prospects of these peptide-based drugs in type 2 diabetes (T2D) management.

Liraglutide Effectiveness in Type 2 Diabetes: Insights from a Real-World Cohort of Portuguese Patients

Liraglutide is a long-acting glucagon-like peptide-1 receptor agonist prescribed to diabetic patients for glycaemic control. To understand the impact of liraglutide in the real-world setting, this study analysed its effects in a Portuguese cohort of Type 2 diabetes patients. This was an observational, multicentric, and retrospective study that included 191 liraglutide-treated patients with at least 12 months of treatment. Patients’ data were collected and analysed during a 24-month follow-up period. Overall, liraglutide treatment effectively reduced HbA1c levels from 8.3% to around 7.5%, after 6, 12, and 24 months (p < 0.001). In fact, 38.2%, 37.2%, and 44.8% of patients at 6, 12, and 24 months, respectively, experienced an HbA1c reduction of at least 1%. Moreover, a persistent reduction in anthropometric features was also observed, with 44.0%, 47.6%, and 54.4% of patients achieving a weight reduction of at least 3% at 6, 12, and 24 months, respectively. Finally, significant improvements were observed in the HDL-c and LDL-c levels. Our results demonstrate that liraglutide effectively promoted the reduction of HbA1c values during routine clinical practice, which was sustained throughout the study. In addition, there were significant improvements in anthropometric parameters and other cardiovascular risk factors.

Incidence of adhesions in patients using liraglutide before laparoscopic sleeve gastrectomy

BACKGROUND

The current study objectively identified the incidence of adhesions between the stomach and pancreas in laparoscopic sleeve gastrectomy (LSG) patients on liraglutide (cases group) and off (control group) liraglutide.

METHODS

This observational prospective study was conducted in the Department of General Surgery at Saudi German Hospital, Al-Aseer, Saudi Arabia (SGH) after approval by the Institutional Review Board. 117 patients with prior use of liraglutide and 101 patients with no liraglutide use scheduled for LSG over 12 months were included. Inclusion criteria included patients undergoing LSG with or without prior use of liraglutide. Exclusion criteria included patients with prior abdominal surgeries, bariatric surgery revisions, prior upper GI scope showing gastritis, Gastroesophageal Reflux Disease (GERD) or any other pathology, and other known causes of other causes of pancreatitis. Using laparoscopy obtained imaging during LSG cases adhesions between the posterior stomach and pancreas were identified.

RESULTS

The mean age of the patients in the cases and control groups was 32.44 ± 9.90 years and 28.23 ± 8.48 years (p = 0.001). The mean BMI of patients in the cases and control groups was 43.56 ± 4.59 and 45.00 ± 4.78, respectively (p = 0.024). 85% of the patients were females, while 17.0% were males in the cases group. 53.5% of the patients were females, while 47.0% were males in the control group (p < 0.001). In the cases group, 48.7% of patients had stopped liraglutide for no obvious reason. Under the cases group, 77.8% of the patients had no adhesions, while 22.2% had adhesions. Under the controls group, no adhesions were seen (p < 0.001).

CONCLUSIONS

Our results for the first time demonstrate an incidence of adhesions in 22.2% of patients undergoing LSG on prior liraglutide intake (p < 0.001). This study brings to light the possibility of adhesions in patients with prior exposure to liraglutide undergoing LSG. Surgeons performing LSG in patients with prior exposure to liraglutide should be cognizant of this possibility, thereby requiring careful meticulous dissection.

A phase I study comparing the pharmacokinetics of the biosimilar (RD12014) with liraglutide (Victoza) in healthy Chinese male subjects

This study aimed to evaluate the pharmacokinetics (PKs), safety, and immunogenicity of the biosimilar (RD12014) compared to reference liraglutide (Victoza) in healthy Chinese male subjects, so as to provide the basis for the similarity evaluation of the two drugs. Eligible subjects were randomized 1:1 to two sequences (RD12014-Victoza or Victoza-RD12014). Subjects received a single 0.6 mg dose of Victoza or RD12014 by abdominal subcutaneous injection during the first period. After a 7-day washout period, subjects received the alternative drug during the second period. Blood samples were collected at predefined timepoints for PKs and immunogenicity assessment. The primary PK end points were maximum plasma concentration (C_max ) and area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUC_0-last ). PK bioequivalence was achieved, if the 90% confidence intervals (CIs) of the geometric mean ratio (GMR) of C_max and AUC_0-last were within the range of 80.00-125.00%. Safety was assessed throughout the study. The 90% CIs of the GMR of RD12014 to Victoza for C_max and AUC_0-last were completely within the range of 80.00-125.00%. Thirteen treatment-related adverse events (TRAEs) were reported in 11 subjects (22.4%) in the RD12014 group, compared to 12 TRAEs reported in 12 subjects (24.5%) in the Victoza group. The blood samples of 49 subjects were negative for anti-drug antibody and the neutralizing antibody was not further detected. This study demonstrated PK similarity of RD12014 to Victoza in healthy Chinese male subjects. Safety and immunogenicity profiles were comparable between the two groups.

Liraglutide Effect on Weight, Glycated Hemoglobin, and Blood Pressure: A Single-Center Experience in the Eastern Province of Saudi Arabia

Background

Liraglutide has pleiotropic effects beneficial to patients with cardiovascular and renal risks. These effects have been linked to weight and blood pressure reduction in type 2 diabetes (T2D) patients. However, whether this reduction is similar in all patients regardless of their ethnicity, baseline demographic, or clinical characteristics is unknown. This study aimed to identify the efficacy of liraglutide on weight, glycated hemoglobin (HbA1c), and blood pressure in Saudi patients with T2D who attended King Fahad Hospital of the University and received liraglutide as add-on therapy to other antihyperglycemic agents. The study also aimed to describe the pattern of change in these clinical parameters before and after the treatment and assess whether sex differences affect liraglutide's efficacy.

Methods

We conducted a retrospective longitudinal study reviewing medical records of 220 Saudi patients with T2D treated at King Fahad Hospital of the University (KFHU), in Al-Khobar city in the Eastern Province of Saudi Arabia, from December 2016 to November 2021. Patient cases were included if the patient was Saudi, aged 18 or older, and received liraglutide in a dose of at least 0.6 mg/day for at least three months in combination with other antihyperglycemic agents/diabetes medications. We recorded the effect on patient HbA1c, systolic blood pressure (SBP) and diastolic blood pressure (DBP), body mass index (BMI), and body weight at baseline, during, and after treatment. We used the paired t-test and repeated measure analysis of variance to compare the mean study parameters before and after treatment. Furthermore, an independent t-test was used to compare the mean study parameters among men and women.

Results

Treatment with liraglutide from 0.6 mg/day to 3 mg/day for three to 18 months had optimal results across the outcomes measured in our cohort study. There was a significant reduction in weight from baseline to 18 months from a mean weight of 97.9±20 kg to 96.51±18.45 kg with (p<0.001). Mean HbA1c at baseline was 9.34%±1.95%, dropped to 7.67%±1.11% (p<0.001) at 18 months. Moreover, mean SBP also significantly decreased from 126.61±10.4 mmHg to 122.48±7.29 mmHg by the last follow-up (p<0.001). Mean DBP was 76.54±8.37 mmHg at baseline and decreased to 74.29±6.22 mmHg at last follow-up (p<0.001). Men treated with liraglutide had greater reductions in weight than women throughout the study (p<0.05), and while men had greater reductions in SBP and DBP than women early in treatment (p<0.05), by the end of treatment, there were no significant differences in blood pressure between men and women. Likewise, we saw no significant difference between HbA1c reductions in men and women treated with liraglutide.

Conclusion

Liraglutide effectively reduces HbA1c, weight, BMI, SBP, and DBP in T2D patients. These study results reflect real-world liraglutide clinical practices from KFHU and can be beneficial for physicians when considering using liraglutide as add-on therapy in this population.

Sex Differences in Response to Treatment with Glucagon-like Peptide 1 Receptor Agonists: Opportunities for a Tailored Approach to Diabetes and Obesity Care

The available data suggest differences in the course of type 2 diabetes mellitus (T2DM) between men and women, influenced by the distinguishing features of the sex. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are a relatively new class of antidiabetic drugs that act by mimicking the function of endogenous glucagon-like peptide 1. They constitute valuable agents for the management of T2DM as, in addition to exerting a strong hypoglycemic action, they present cardiorenal protective properties, promote weight loss, and have a good safety profile, particularly with respect to the risk of hypoglycemia. Due to the precedent of studies having identified sexual dimorphic elements regarding the action of other antidiabetic agents, ongoing research has attempted to examine whether this is also the case for GLP-1 RAs. Until now, sex differences have been observed in the impact of GLP1-RAs on glycemic control, weight reduction, and frequency of adverse events. On the contrary, the question of whether these drugs differentially affect the two sexes with respect to cardiovascular risk and incidence of major adverse cardiovascular events remains under investigation. Knowledge of the potential sex-specific effects of these medications is extremely useful for the implementation of individualized therapeutic plans in the treatment of T2DM. This narrative review aims to present the available data regarding the sex-specific action of GLP-1 RAs as well as to discuss the potential pathophysiologic mechanisms explaining these dissimilarities.

Clinical Impact of Liraglutide as a Treatment of Obesity

Obesity is defined as a chronic, complex, relapsing disease characterized by excessive adipose tissue. Obesity impacts an individual's health by increasing complications such as prediabetes, type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, metabolic syndrome, cardiovascular disease, nonalcoholic fatty liver disease (NAFLD), cancers (eg endometrial), and obstructive sleep apnea (OSA). With the increase of obesity prevalence and its negative influences on individuals' quality of life, there is a great need for therapy with a purpose to produce sustainable weight loss of more than 10% in order to improve or even reverse the progress of obesity related complications. The GLP-1 analogue, liraglutide reduce food consumption, promote weight reduction and improve metabolic functions. The primary mechanism of GLP-1 effect on food intake, metabolism, and weight reduction is mainly due to its actions on peripheral (vagal) and central pathways and activation of hindbrain and hypothalamus. The average weight reduction induced by liraglutide was significant and the weight loss was maintained as long as the patients on therapy. Liraglutide has advantages on weight loss maintenance and promoting cardiovascular disease (CVD) risk reduction, by decreasing systolic blood pressure and glycemic index. In this review, we aim to explain the mechanism of action of Liraglutide, its pharmacokinetic properties, its clinical impact on obesity and its safety and tolerability.

GLP-1 Receptor Agonists: Beyond Their Pancreatic Effects

Glucagon like peptide-1 (GLP-1) is an incretin secretory molecule. GLP-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes (T2DM) due to their attributes such as body weight loss, protection of islet β cells, promotion of islet β cell proliferation and minimal side effects. Studies have found that GLP-1R is widely distributed on pancreatic and other tissues and has multiple biological effects, such as reducing neuroinflammation, promoting nerve growth, improving heart function, suppressing appetite, delaying gastric emptying, regulating blood lipid metabolism and reducing fat deposition. Moreover, GLP-1RAs have neuroprotective, anti-infectious, cardiovascular protective, and metabolic regulatory effects, exhibiting good application prospects. Growing attention has been paid to the relationship between GLP-1RAs and tumorigenesis, development and prognosis in patient with T2DM. Here, we reviewed the therapeutic effects and possible mechanisms of action of GLP-1RAs in the nervous, cardiovascular, and endocrine systems and their correlation with metabolism, tumours and other diseases.

Treatment With Liraglutide Exerts Neuroprotection After Hypoxic-Ischemic Brain Injury in Neonatal Rats via the PI3K/AKT/GSK3β Pathway

Neonatal hypoxic–ischemic (HI) brain injury is a detrimental disease, which results in high mortality and long-term neurological deficits. Nevertheless, the treatment options for this disease are limited. Thus, the aim of the present study was to assess the role of liraglutide in neonatal HI brain injury in rats and investigate the associated mechanisms. The results showed that treatment with liraglutide significantly reduced infarct volume and ameliorated cerebral edema, decreased inflammatory response, promoted the recovery of tissue structure, and improved prognosis following HI brain injury. Moreover, treatment with liraglutide inhibited apoptosis and promoted neuronal survival both in the rat model and following oxygen-glucose deprivation (OGD) insult. LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), partially reversed these therapeutic effects, suggesting that the PI3K/protein kinase B (Akt) pathway was involved. In conclusion, our data revealed that treatment with liraglutide exerts neuroprotection after neonatal HI brain injury via the PI3K/Akt/glycogen synthase kinase-3β (GSK3β) pathway and may be a promising therapy for this disease.

Trial design and baseline data for LIRA-PRIME: A randomized trial investigating the efficacy of liraglutide in controlling glycaemia in type 2 diabetes in a primary care setting

AIMS

Using a pragmatic approach, the LIRA-PRIME trial aims to address a knowledge gap by comparing efficacy in controlling glycaemia with glucagon-like peptide-1 analog liraglutide vs oral antidiabetic drugs (OADs) in patients with type 2 diabetes (T2D) uncontrolled with metformin monotherapy in primary care practice. We report the study design and patient baseline characteristics.

MATERIALS AND METHODS

This 104-week, two-arm, open-label, active-controlled trial is active in 219 primary care practices across nine countries. At screening, eligible patients with T2D were at least 18 years of age, had been using a stable daily dose of metformin ≥1500 mg or the maximum tolerated dose for ≥60 days, and had a glycated haemoglobin (HbA1c) of 7.5% to 9.0%, measured ≤90 days before screening. Patients were randomized (1:1) to liraglutide or OAD, both in addition to pre-trial metformin. Individual OADs were chosen by the treating physician based on local guidelines. The primary endpoint is time to inadequate glycaemic control, defined as HbA1c above 7.0% at two scheduled consecutive visits after the first 26 weeks of treatment.

RESULTS

The trial randomized 1997 patients with a mean (standard deviation) age of 56.9 (10.8) years, T2D duration of 7.2 (5.9) years (range, <1-47 years), and HbA1c of 8.2%. One-fifth of patients had a history of diabetes complications, and most were overweight (24.8%) or had obesity (65.3%).

CONCLUSIONS

This pragmatically designed, large-scale, multinational, randomized clinical trial will help guide treatment decisions for patients with T2D who are inadequately controlled with metformin monotherapy and treated in primary care.

Intentional overdose of liraglutide in a non-diabetic patient causing severe hypoglycemia

ABSTRACTCases of liraglutide overdose are rare in the literature. Prior reports have not found hypoglycemia related to the medication overdose. We describe a case of a non-diabetic patient who intentionally overdosed on liraglutide leading to severe hypoglycemia. The patient required admission to the intensive care unit for a dextrose infusion and close monitoring. Glucagon-like protein-1 agonists are recognized for their safety and rarely causing hypoglycemia in diabetic patients. However, in this case the patient's non-diabetic status may have put him at risk for hypoglycemia in contrast to prior cases showing no hypoglycemia in diabetic patients. The case highlights the possible dangers of liraglutide overdose and need for blood glucose monitoring in the acute presentation.

Liraglutide in Type 2 Diabetes Mellitus: Clinical Pharmacokinetics and Pharmacodynamics

Liraglutide is an acylated glucagon-like peptide-1 analogue with 97 % amino acid homology with native glucagon-like peptide-1 and greatly protracted action. It is widely used for the treatment of type 2 diabetes mellitus, and administered by subcutaneous injection once daily. The pharmacokinetic properties of liraglutide enable 24-h exposure coverage, a requirement for 24-h glycaemic control with once-daily dosing. The mechanism of protraction relates to slowed release from the injection site, and a reduced elimination rate owing to metabolic stabilisation and reduced renal filtration. Drug exposure is largely independent of injection site, as well as age, race and ethnicity. Increasing body weight and male sex are associated with reduced concentrations, but there is substantial overlap between subgroups; therefore, dose escalation should be based on individual treatment outcome. Exposure is reduced with mild, moderate or severe renal or hepatic impairment. There are no clinically relevant changes in overall concentrations of various drugs (e.g. paracetamol, atorvastatin, griseofulvin, digoxin, lisinopril and oral combination contraceptives) when co-administered with liraglutide. Pharmacodynamic studies show multiple beneficial actions with liraglutide, including improved fasting and postprandial glycaemic control (mediated by increased insulin and reduced glucagon levels and minor delays in gastric emptying), reduced appetite and energy intake, and effects on postprandial lipid profiles. The counter-regulatory hormone response to hypoglycaemia is largely unaltered. The effects of liraglutide on insulin and glucagon secretion are glucose dependent, and hence the risk of hypoglycaemia is low. The pharmacokinetic and pharmacodynamic properties of liraglutide make it an important treatment option for many patients with type 2 diabetes.

Lack of effect of prolonged treatment with liraglutide on cardiac remodeling in rats after acute myocardial infarction

Following the acute phase of a myocardial infarction, a set of structural and functional changes evolves in the myocardium, collectively referred to as cardiac remodeling. This complex set of processes, including interstitial fibrosis, inflammation, myocyte hypertrophy and apoptosis may progress to heart failure. Analogs of the incretin hormone glucagon-like peptide 1 (GLP-1) have shown some promise as cardioprotective agents. We hypothesized that a long-acting GLP-1 analog liraglutide would ameliorate cardiac remodeling over the course of 4 weeks in a rat model of non-reperfused myocardial infarction. In 134 male Sprague Dawley rats myocardial infarctions were induced by ligation of the left anterior descending coronary artery. Rats were randomized to either subcutaneous injection of placebo or 0.3mg liraglutide once daily. Cardiac magnetic resonance imaging was performed after 4 weeks. Histology of the infarcted and remote non-infarcted myocardium, selected molecular remodeling markers and mitochondrial respiration in fibers of remote non-infarcted myocardium were analyzed. Left ventricular end diastolic volume increased in the infarcted hearts by 62% (from 0.58±0.03mL to 0.95±0.07mL, P<0.05) compared to sham operated hearts and left ventricle ejection fraction decreased by 37% (63±1%-40±3%, P<0.05). Increased interstitial fibrosis and phosphorylation of p38 Mitogen Activated Protein Kinase were observed in the non-infarct regions. Mitochondrial fatty acid oxidation was impaired. Liraglutide did not affect any of these alterations. Four-week treatment with liraglutide did not affect cardiac remodeling following a non-reperfused myocardial infarction, as assessed by cardiac magnetic resonance imaging, histological and molecular analysis and measurements of mitochondrial respiration.

Cost-Effectiveness of Liraglutide Versus Dapagliflozin for the Treatment of Patients with Type 2 Diabetes Mellitus in the UK

INTRODUCTION

To date there is a lack of economic analysis comparing glucagon-like peptide-1 receptor agonists (GLP-1RAs) to sodium-glucose co-transporter 2 inhibitors (SGLT-2i) for the treatment of type 2 diabetes mellitus (T2DM). Liraglutide and dapagliflozin are the most commonly prescribed GLP-1RA and SGLT-2i in the UK. This analysis investigated the cost-effectiveness of liraglutide 1.2 and 1.8 mg/day compared to dapagliflozin 10 mg/day for the treatment of T2DM in the UK in patients on dual and triple antidiabetic therapy.

METHODS

Cost-effectiveness analysis was conducted in the QuintilesIMS CORE Diabetes Model (CDM). The model estimated expected costs and outcomes over a lifetime horizon using the UK national payer perspective. Liraglutide efficacy estimates and patient characteristics were sourced from a trial in patients on prior metformin monotherapy, and from a trial in patients on prior combination therapy. Comparative efficacy data for the other interventions were derived from a network meta-analysis. Utility inputs were extracted from a systematic literature review. Costs are presented in Great British Pound (GBP), 2016 values.

RESULTS

In dual and triple therapy, liraglutide 1.2 mg was less costly and more effective compared with dapagliflozin 10 mg, providing a QALY gain of 0.04 and cost savings of GBP 11 per patient in dual therapy, and a QALY gain of 0.06 and cost savings of GBP 71 per patient in triple therapy. For liraglutide 1.8 mg, increased efficacy and costs compared with dapagliflozin 10 mg were observed in both dual and triple therapy. In dual therapy, a QALY gain of 0.07 and additional costs of GBP 888 per patient yielded an ICER of GBP 13,227, whereas in triple therapy a QALY gain of 0.07 and additional cost of GBP 791 per patient gave an ICER of 11,857.

CONCLUSION

This long-term modelling analysis found that both dosages of liraglutide may be cost-effective treatment alternatives as part of a dual or a triple antidiabetic therapy in patients for whom an SGLT-2i therapy is considered.

FUNDING

Novo Nordisk.

Cardiovascular outcome studies with incretin-based therapies: Comparison between DPP-4 inhibitors and GLP-1 receptor agonists

Dipeptidyl peptidase-4 inhibitors (DPP-4is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) represent two distinct classes of incretin-based therapies used for the treatment of type 2 diabetes. Non-inferiority versus placebo was shown in large prospective cardiovascular outcome trials in patients with high cardiovascular risk: SAVOR-TIMI 53 (saxagliptin), EXAMINE (alogliptin), and TECOS (sitagliptin); ELIXA (lixisenatide), LEADER (liraglutide) and SUSTAIN 6 (semaglutide). The promises raised by meta-analyses of phase 2-3 trials with DPP-4is were non confirmed as no cardiovascular protection could be evidenced. However, LEADER showed a significant reduction in major cardiovascular events, myocardial infarction, cardiovascular and all-cause mortality in patients treated by liraglutide compared to placebo. These positive results contrasted with the non-inferiority results with lixisenatide in ELIXA. They were partially confirmed with semaglutide in SUSTAIN 6 despite the absence of reduction in cardiovascular mortality. Hospitalisation for heart failure was not increased except with saxagliptin in SAVOR-TIMI 53. The reasons for different outcomes between trials remain largely unknown as well as the precise underlying mechanisms explaining the cardiovascular protection by liraglutide. The clinical relevance of results with DPP-4is and GLP-1RAs is discussed. Ongoing trials with linagliptin and several once-weekly GLP-1RAs should provide new insights into remaining fundamental questions.

The Dual Amylin- and Calcitonin-Receptor Agonist KBP-042 Works as Adjunct to Metformin on Fasting Hyperglycemia and HbA1c in a Rat Model of Type 2 Diabetes

KBP-042 is a dual amylin and calcitonin receptor agonist that increases glucose tolerance and insulin action and reduces body weight in rat models of obesity and prediabetes. The objective of the present study was to 1) evaluate KBP-042 as a treatment of late-stage type 2 diabetes in a rat model and 2) assess the value of adding KBP-042 to the standard of care, metformin, to consider KBP-042 as a relevant drug for treating patients with type 2 diabetes. Two studies were included: an intervention study and a prevention study. In the intervention study, treatment with 5 µg/kg KBP-042 was initiated in 11-week-old Zucker diabetic fatty (ZDF) rats, in which glucose tolerance, fasting glycemia, and glycated hemoglobin were assessed after 4 weeks. In the prevention study, either metformin (400 mg/kg), KBP-042 (5 µg/kg), or a combination of both were administered to ZDF rats for a total of 9 weeks. Glycemia, glucose tolerance, and insulin tolerance were tested. Furthermore, fasting plasma insulin and glucagon levels were evaluated. Finally, pancreatic content of insulin was assessed as a surrogate marker of beta-cell mass. It was found that KBP-042 was efficient in lowering fasting plasma glucose as well as improving glucose tolerance, both as prevention and intervention of disease progression. Furthermore, KBP-042 was efficient in combination with metformin and had additional effects compared with either therapy alone. In conclusion, KBP-042 is a highly relevant therapeutic candidate against type 2 diabetes, effective both as an add-on therapy to metformin and as a stand-alone therapy.

Basal Glucose Can Be Controlled, but the Prandial Problem Persists-It's the Next Target!

Both basal and postprandial elevations contribute to the hyperglycemic exposure of diabetes, but current therapies are mainly effective in controlling the basal component. Inability to control postprandial hyperglycemia limits success in maintaining overall glycemic control beyond the first 5 to 10 years after diagnosis, and it is also related to the weight gain that is common during insulin therapy. The "prandial problem"-comprising abnormalities of glucose and other metabolites, weight gain, and risk of hypoglycemia-deserves more attention. Several approaches to prandial abnormalities have recently been studied, but the patient populations for which they are best suited and the best ways of using them remain incompletely defined. Encouragingly, several proof-of-concept studies suggest that short-acting glucagon-like peptide 1 agonists or the amylin agonist pramlintide can be very effective in controlling postprandial hyperglycemia in type 2 diabetes in specific settings. This article reviews these topics and proposes that a greater proportion of available resources be directed to basic and clinical research on the prandial problem.

Dogfish glucagon analogues counter hyperglycaemia and enhance both insulin secretion and action in diet-induced obese diabetic mice

AIMS

To investigate the antidiabetic actions of three dogfish glucagon peptide analogues [known glucagon-like peptide-1 and glucagon receptor co-agonists] after chronic administration in diet-induced high-fat-diet-fed diabetic mice.

MATERIALS AND METHODS

National Institutes of Health Swiss mice were pre-conditioned to a high-fat diet (45% fat) for 100 days, and control mice were fed a normal diet (10% fat). Normal diet control and high-fat-fed control mice received twice-daily intraperitoneal (i.p.) saline injections, while the high-fat-fed treatment groups (n = 8) received twice-daily injections of exendin-4(1-39), [S2a]dogfish glucagon, [S2a]dogfish glucagon exendin-4(31-39) or [S2a]dogfish glucagon-Lys(30) -γ-glutamyl-PAL (25 nmol/kg body weight) for 51 days.

RESULTS

After dogfish glucagon analogue treatment, there was a rapid and sustained decrease in non-fasting blood glucose and an associated insulinotropic effect (analysis of variance, p < .05 to <.001) compared with saline-treated high-fat-fed controls. All peptide treatments significantly improved i.p. and oral glucose tolerance with concomitant increased insulin secretion compared with saline-treated high-fat-fed controls (p <.05 to <.001). After chronic treatment, no receptor desensitization was observed but insulin sensitivity was enhanced for all peptide-treated groups (p < .01 to <.001) except [S2a]dogfish glucagon. Both exendin-4 and [S2a]dogfish glucagon exendin-4(31-39) significantly reduced plasma triglyceride concentrations compared with those found in lean controls (p = .0105 and p = .0048, respectively). Pancreatic insulin content was not affected by peptide treatments but [S2a]dogfish glucagon and [S2a]dogfish glucagon exendin-4(31-39) decreased pancreatic glucagon by 28%-34% (p = .0221 and p = .0075, respectively). The percentage of β-cell area within islets was increased by exendin-4 and peptide analogue treatment groups compared with high-fat-fed controls and the β-cell area decreased (p < .05 to <.01).

CONCLUSIONS

Overall, dogfish glucagon co-agonist analogues had several beneficial metabolic effects, showing therapeutic potential for type 2 diabetes.

Single dose and repeated administrations of liraglutide alter energy metabolism in the brains of young and adult rats

Liraglutide is a human glucagon-like peptide-1 (GLP-1) analogue that was recently approved to treat obesity in some countries. Considering that liraglutide effects on brain energy metabolism are little known, we evaluated the effects of liraglutide on the energy metabolism. Animals received a single or daily injection of saline or liraglutide during 7 days (25, 50, 100, or 300 μg/kg i.p.). Twenty-four hours after the single or last injection, the rats were euthanized and the hypothalamus, prefrontal cortex, cerebellum, hippocampus, striatum, and posterior cortex were isolated. Our results demonstrated that a single dose of liraglutide in young rats increased the activity of complexes and inhibited creatine kinase activity. Repeated administrations of liraglutide in young rats reduced the activity of complexes and activated creatine kinase activity. In adult rats, a single dose of liraglutide reduced the activity of complex I and creatine kinase and increased the activity of complexes II and IV. Repeated administrations of liraglutide in adult rats increased the activity of complexes I and IV and reduced the activity of complex II and creatine kinase. We concluded that liraglutide may interfere in energy metabolism, because analysis of different times of administrations, concentrations, and level of brain development leads to divergent results.

Novel dual agonist peptide analogues derived from dogfish glucagon show promising in vitro insulin releasing actions and antihyperglycaemic activity in mice

The antidiabetic potential of thirteen novel dogfish glucagon derived analogues were assessed in vitro and in acute in vivo studies. Stable peptide analogues enhanced insulin secretion from BRIN-BD11 β-cells (p < 0.001) and reduced acute glycaemic responses following intraperitoneal glucose (25 nmol/kg) in healthy NIH Swiss mice (p < 0.05-p<0.001). The in vitro insulinotropic actions of [S2a]dogfish glucagon, [S2a]dogfish glucagon-exendin-4(31-39) and [S2a]dogfish glucagon-Lys(30)-γ-glutamyl-PAL, were blocked (p < 0.05-p<0.001) by the specific GLP-1 and glucagon receptor antagonists, exendin-4(9-39) and (desHis(1)Pro(4)Glu(9))glucagon amide but not by (Pro(3))GIP, indicating lack of GIP receptor involvement. These analogues dose-dependently stimulated cAMP production in GLP-1 and glucagon (p < 0.05-p<0.001) but not GIP-receptor transfected cells. They improved acute glycaemic and insulinotropic responses in high-fat fed diabetic mice and in wild-type C57BL/6J and GIPR-KO mice (p < 0.05-p<0.001), but not GLP-1R-KO mice, confirming action on GLP-1 but not GIP receptors. Overall, dogfish glucagon analogues have potential for diabetes therapy, exerting beneficial metabolic effects via GLP-1 and glucagon receptors.

Insulin Degludec/Liraglutide: A Review in Type 2 Diabetes

Insulin degludec/liraglutide (Xultophy(®)), a fixed-ratio combination of an ultra-long-acting insulin analogue and a glucagon-like protein-1 (GLP-1) receptor agonist, is available in the EU for the management of inadequately controlled type 2 diabetes. Once-daily subcutaneous insulin degludec/liraglutide as add-on therapy to oral antidiabetics was effective and generally well tolerated in adults with inadequately controlled type 2 diabetes in several well designed 26-week phase III trials. In insulin-naive patients, add-on insulin degludec/liraglutide provided significantly greater improvements in glycated haemoglobin (HbA1c) levels than add-on insulin degludec, liraglutide or placebo, or unchanged GLP-1 receptor agonists (i.e. liraglutide or exenatide). In the extension of one of these trials, the efficacy of add-on insulin degludec/liraglutide was maintained for a total of 52 weeks. In insulin-experienced patients, add-on insulin degludec/liraglutide was significantly more effective with regard to improvements in HbA1c levels than add-on insulin degludec (at equivalent doses) or ongoing insulin glargine therapy. Add-on insulin degludec/liraglutide was associated with a lower incidence of confirmed hypoglycaemia than add-on insulin degludec in insulin-naive patients or ongoing insulin glargine in insulin-experienced patients, and a lower initial rate of nausea than add-on liraglutide. Thus, once-daily subcutaneous insulin degludec/liraglutide is a useful add-on therapy option for adult patients with inadequately controlled type 2 diabetes.

Combination therapies in the management of type 2 diabetes: the use of insulin degludec/liraglutide

The global burden of type 2 diabetes is estimated to currently affect over 350 million people worldwide and is anticipated to continue increasing over the next 20 years. Current treatment guidelines recommend the choice of pharmacotherapy based upon patient-specific parameters, with combination therapy for patients with a hemoglobin A1c level ≥9%. A new combination therapy of insulin degludec + liraglutide provides a long-acting basal insulin with a glucagon-like peptide agonist. In clinical trials, this combination product has reduced hemoglobin A1c and fasting plasma glucose more than the individual agents alone. Further advantages observed with this combination include weight loss and decrease in hypoglycemia compared to basal insulin alone.

Liraglutide: a review of its use in the management of obesity

Globally, obesity has reached epidemic proportions and poses an ever increasing burden from a societal and healthpayer perspective. Although lifestyle interventions are fundamental in its management, in the real world setting most obese or overweight adults require adjunctive pharmacotherapy to achieve clinically relevant reductions in bodyweight (i.e. a ≥5 % reduction). Subcutaneous liraglutide (Saxenda(®)) 3 mg once daily is indicated as an adjunct to a reduced-calorie diet and increased physical activity for chronic bodyweight management in adults with an initial body mass index (BMI) of ≥30 kg/m(2) (obese) or a BMI of ≥27 kg/m(2) (overweight) and at least one bodyweight-related comorbidity [e.g. hypertension, dyslipidaemia, type 2 diabetes mellitus or obstructive sleep apnoea (OSA)]. In phase III trials (32 or 56 weeks' duration) in these populations, subcutaneous liraglutide was associated with clinically relevant reductions in fasting bodyweight and was generally well tolerated. Liraglutide was significantly more effective than placebo in terms of reductions in fasting bodyweight and waist circumference, and improvements in some biomarkers of cardiovascular risk. Improvements in bodyweight were maintained after up 2 years of liraglutide therapy. In nondiabetic adults with moderate to severe OSA, liraglutide improved apnoea-hypopnoea index scores at 32 weeks, which was largely driven by significant reductions in bodyweight. In the absence of head-to-head trials, the relative position of individual anti-obesity drugs remains to be fully determined. In the meantime, liraglutide is an emerging option, as an adjunct to a reduced-calorie diet and increased physical activity, for chronic bodyweight management in obese adults and overweight adults with at least one bodyweight-related comorbidity.

A new GLP-1 analogue with prolonged glucose-lowering activity in vivo via backbone-based modification at the N-terminus

Glucagon-like peptide-1 (GLP-1) is an endogenous insulinotropic hormone with wonderful glucose-lowering activity. However, its clinical use in type II diabetes is limited due to its rapid degradation at the N-terminus by dipeptidyl peptidase IV (DPP-IV). Among the N-terminal modifications of GLP-1, backbone-based modification was rarely reported. Herein, we employed two backbone-based strategies to modify the N-terminus of tGLP-1. Firstly, the amide N-methylated analogues 2-6 were designed and synthesized to make a full screening of the N-terminal amide bonds, and the loss of GLP-1 receptor (GLP-1R) activation indicated the importance of amide H-bonds. Secondly, with retaining the N-terminal amide H-bonds, the β-peptide replacement strategy was used and analogues 7-13 were synthesized. By two rounds of screening, analogue 10 was identified. Analogue 10 greatly improved the DPP-IV resistance with maintaining good GLP-1R activation in vitro, and showed approximately a 4-fold prolonged blood glucose-lowering activity in vivo in comparison with tGLP-1. This modification strategy will benefit the development of GLP-1-based anti-diabetic drugs.

Drug updates and approvals: 2015 in review

This article highlights important prescribing information for some drugs that received FDA approval within the past year. These include: atazanavir and cobicistat (Evotaz®), ceftazidime and avibactam (Avycaz®), edoxaban (Savaysa®), ivabradine (Corlanor®), liraglutide (rDNA origin) injection (Saxenda®), perindopril arginine and amlodipine besylate (Prestalia®), and secukinumab (Cosentyx®) subcutaneous injection.

Subcutaneous fluid and drug delivery: safe, efficient and inexpensive

Patients with difficult venous access or oral intolerance and clinical situations with inadequate response to oral therapy have generated the need for alternative routes of delivery for drugs and fluids.

The purpose of this study was to conduct a systematic review examining the evidence for subcutaneous (SC) administration of drugs and/or fluids.

We used a broad search strategy using electronic databases CINAHL, EMBASE, PubMed and Cochrane library, key terms and ‘Medical Subject Headings’ (MeSH) such as ‘subcutaneous route’, ‘hypodermoclysis’ and the name/group of the most used drugs via this route (e.g. ‘ketorolac, morphine, ceftriaxone’, ‘analgesics, opioids, antibiotics’).

We conclude that the SC route is an effective alternative for rehydration in patients with mild–moderate dehydration and offers a number of potential advantages in appropriately selected scenarios. Experience of administering drugs by this route suggests that it is well tolerated and is associated with minimal side-effects.

Liraglutide is neurotrophic and neuroprotective in neuronal cultures and mitigates mild traumatic brain injury in mice

Traumatic brain injury (TBI), a brain dysfunction for which there is no present effective treatment, is often caused by a concussive impact to the head and affects an estimated 1.7 million Americans annually. Our laboratory previously demonstrated that exendin-4, a long-lasting glucagon-like peptide 1 receptor (GLP-1R) agonist, has neuroprotective effects in cellular and animal models of TBI. Here, we demonstrate neurotrophic and neuroprotective effects of a different GLP-1R agonist, liraglutide, in neuronal cultures and a mouse model of mild TBI (mTBI). Liraglutide promoted dose-dependent proliferation in SH-SY5Y cells and in a GLP-1R over-expressing cell line at reduced concentrations. Pre-treatment with liraglutide rescued neuronal cells from oxidative stress- and glutamate excitotoxicity-induced cell death. Liraglutide produced neurotrophic and neuroprotective effects similar to those of exendin-4 in vitro. The cAMP/PKA/pCREB pathway appears to play an important role in this neuroprotective activity of liraglutide. Furthermore, our findings in cell culture were well-translated in a weight drop mTBI mouse model. Post-treatment with a clinically relevant dose of liraglutide for 7 days in mice ameliorated memory impairments caused by mTBI when evaluated 7 and 30 days post trauma. These data cross-validate former studies of exendin-4 and suggest that liraglutide holds therapeutic potential for the treatment of mTBI. Exendin-4, a long-lasting glucagon-like peptide 1 receptor (GLP-1R) agonist, has neuroprotective effects in cellular and animal models of traumatic brain injury (TBI). Here, we demonstrate neurotrophic and neuroprotective effects of a different GLP-1R agonist, liraglutide, in neuronal cultures and a mouse model of mild TBI (mTBI). Liraglutide promoted dose-dependent proliferation in SH-SY5Y cells and in a GLP-1R over-expressing cell line at reduced concentrations. Pretreatment with liraglutide rescued neuronal cells from oxidative stress- and glutamate excitotoxicity-induced cell death. Liraglutide produced neurotrophic and neuroprotective effects similar to those of exendin-4 in vitro, likely involving the cAMP/PKA/pCREB pathway. Our findings in cell culture were well-translated in a weight-drop mTBI mouse model. Post-treatment with a clinically relevant dose of liraglutide for 7 days in mice ameliorated memory impairments caused by mTBI.

Host-defense peptides of the skin with therapeutic potential: From hagfish to human

It is now well established that peptides that were first identified on the basis of their ability to inhibit growth of bacteria and fungi are multifunctional and so are more informatively described as host-defense peptides. In some cases, their role in protecting the organism against pathogenic microorganisms, although of importance, may be secondary. A previous article in the journal (Peptides 2014; 57:67-77) assessed the potential of peptides present in the skin secretions of frogs for development into anticancer, antiviral, immunomodulatory and antidiabetic drugs. This review aims to extend the scope of this earlier article by focusing upon therapeutic applications of host-defense peptides present in skin secretions and/or skin extracts of species belonging to other vertebrate classes (Agnatha, Elasmobranchii, Teleostei, Reptilia, and Mammalia as represented by the human) that supplement their potential role as anti-infectives for use against multidrug-resistant microorganisms.

Adverse Effects of GLP-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of injective anti-diabetic drugs that improve glycemic control and many other atherosclerosis-related parameters in patients with type 2 diabetes (T2D). However, the use of this relatively new class of drugs may be associated with certain adverse effects. Concerns have been expressed regarding the effects of these drugs on pancreatic and thyroid tissue, since animal studies and analyses of drug databases indicate an association of GLP-1 receptor agonists with pancreatitis, pancreatic cancer, and thyroid cancer. However, several meta-analyses failed to confirm a cause-effect relation between GLP-1 receptor agonists and the development of these adverse effects. One benefit of GLP-1 receptor agonists is that they do not cause hypoglycemia when combined with metformin or thiazolidinediones, but the dose of concomitant sulphonylurea or insulin may have to be decreased to reduce the risk of hypoglycemic episodes. On the other hand, several case reports have linked the use of these drugs, mainly exenatide, with the occurrence of acute kidney injury, primarily through hemodynamic derangement due to nausea, vomiting, and diarrhea. The most common symptoms associated with the use of GLP-1 receptor agonists are gastrointestinal symptoms, mainly nausea. Other common adverse effects include injection site reactions, headache, and nasopharyngitis, but these effects do not usually result in discontinuation of the drug. Current evidence shows that GLP-1 receptor agonists have no negative effects on the cardiovascular risk of patients with T2D. Thus, GLP-1 receptor agonists appear to have a favorable safety profile, but ongoing trials will further assess their cardiovascular effects. The aim of this review is to analyze critically the available data regarding adverse events of GLP-1 receptor agonists in different anatomic systems published in Pubmed and Scopus. Whenever possible, certain differences between GLP-1 receptor agonists are described. The review also provides the reader with structured data that compare the rates of the most common adverse effects for each of the various GLP-1 receptor agonists.