Effects of Exenatide on Kidney Function, Adverse Events, and Clinical End Points of Kidney Disease in Type 2 Diabetes

Effects of GLP-1 receptor agonists on cardiovascular outcomes in patients with type 2 diabetes and chronic kidney disease: A systematic review and meta-analysis

AIM

To evaluate the cardiovascular outcomes of glucagon-like peptide-1 receptor agonists (GLP1-RA) in patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD).

MATERIALS AND METHODS

We searched PubMed, Ovid MEDLINE, CINAHL, and Web of Science databases for randomized controlled trials reporting event rates for a composite cardiovascular outcome of cardiovascular death, myocardial infarction, and stroke in patients with T2DM and CKD receiving GLP1-RA or placebo. Studies were restricted to those reporting specific event rates for patients with CKD separately from the overall population. We conducted a meta-analysis using a random-effects model. This meta-analysis was registered on PROSPERO (CRD42022320157).

RESULTS

A total of four studies comprising 7130 patients was included in our analysis. Four different GLP1-RA were assessed in a population with CKD defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² . Treatment with GLP1-RA was not associated with a significant reduction in the composite cardiovascular end point of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke (odds ratio (OR) 0.80; 95% confidence interval (CI), 0.59-1.07; p = 0.13) among patients with T2DM and CKD. Individual components of the composite cardiovascular end point were assessed in two trials and did not show evidence of an effect of GLP1-RA in reducing cardiovascular end points.

CONCLUSIONS

Pooled analysis of clinical trials reporting separate cardiovascular events rates in patients with T2DM and CKD did not find GLP1-RA to be associated with a reduction in composite cardiovascular event rates. Select GLP1-RA may offer cardiovascular event reduction in patients with T2DM and CKD, but this does not appear to be a class effect. Use of GLP1-RA with demonstrated cardiovascular benefits should be preferred in patients with CKD and T2DM to further reduce cardiovascular risk.

Renoprotection in diabetic kidney disease: can incretin-based therapies deliver?

PURPOSE OF REVIEW

Incretin-based therapies mimic or augment the gut-hormone glucagon-like peptide (GLP)-1 and, due to their glucose-lowering potential and beneficial safety profile, as well as their cardiovascular safety and/or protection, are prescribed on a large scale to treat individuals with type 2 diabetes (T2D). However, whether the two drug-classes that belong to this category, respectively GLP-1 receptor agonists and dipeptidyl peptidase (DPP)-4 inhibitors, also reduce the risk of diabetic kidney disease (DKD) is at present heavily debated. This review aims to discuss the current evidence.

RECENT FINDINGS

Evidence from land-mark cardiovascular safety trials, conducted in people with T2D at high-cardiovascular risk but with normal kidney function, suggest that both drug-classes have excellent renal safety profiles. In contrast to DPP-4 inhibitors, it seems that GLP-1 receptor agonists reduce albuminuria and possibly induce a reduction of estimated glomerular filtration rate decline. However, the trials were not properly designed to test renal outcomes.

SUMMARY

A dedicated renal trial involving a GLP-1 receptor agonist has recently commenced and will answer the question whether these drugs will be effective to reduce DKD. Moreover, ongoing mechanism-of-action studies are focusing on the renal physiological effects of GLP-1, as the effects on particularly albuminuria reduction remain currently unexplained.

Clinical Outcomes by Albuminuria Status with Dulaglutide versus Insulin Glargine in Participants with Diabetes and CKD: AWARD-7 Exploratory Analysis

Background

In the AWARD-7 trial of participants with type 2 diabetes (T2DM) and moderate-to-severe CKD, dulaglutide (DU) treatment slowed decline in eGFR compared with insulin glargine (IG). Treatment with doses of either DU or IG resulted in similar levels of glycemic control and BP. The aim of this analysis was to determine the risk of clinical event outcomes between treatment groups.

Methods

Participants with T2DM and CKD categories 3-4 were randomized (1:1:1) to 0.75 or 1.5 mg DU weekly or IG daily as basal therapy, with titrated insulin lispro, for 1 year. The time to occurrence of the composite outcome of ≥40% eGFR decline, ESKD, or death due to kidney disease was compared using a Cox proportional-hazards model.

Results

Patients treated with 1.5 mg DU weekly versus IG daily for 1 year had a lower risk of ≥40% eGFR decline or ESKD events in the overall study population (5% versus 11%; hazard ratio, 0.45; 95% CI, 0.20 to 0.97; P=0.04). Most events occurred in the subset of patients with macroalbuminuria, where risk of the composite outcome was substantially lower for 1.5 mg DU versus IG (7% versus 22%; hazard ratio, 0.25; 95% CI, 0.10 to 0.68; P=0.006). No deaths due to kidney disease occurred.

Conclusions

Treatment with 1.5 mg DU weekly was associated with a clinically relevant risk reduction of ≥40% eGFR decline or ESKD compared with IG daily, particularly in the macroalbuminuria subgroup of participants with T2DM and moderate-to-severe CKD.

Exenatide twice-daily does not affect renal function or albuminuria compared to titrated insulin glargine in patients with type 2 diabetes mellitus: A post-hoc analysis of a 52-week randomised trial

AIMS

To compare the effects of long-term treatment with the GLP-1RA exenatide twice-daily versus titrated insulin glargine (iGlar) on renal function and albuminuria in type 2 diabetes (T2DM) patients.

METHODS

We post-hoc evaluated renal outcome-data of 54 overweight T2DM patients (mean  ± SD age 60 ± 8 years, HbA1c 7.5 ± 0.9%, eGFR 86 ± 16 mL/min/1.73 m², median [IQR] urinary albumin-to-creatinine-ratio (UACR) 0.75 [0.44-1.29] mg/mmol) randomised to exenatide 10 µg twice-daily or titrated iGlar on-top-of metformin for 52-weeks. Renal efficacy endpoints were change in creatinine clearance (CrCl) and albuminuria (urinary albumin-excretion [UAE] and UACR) based on 24-h urines, collected at baseline and Week-52. eGFR and exploratory endpoints were collected throughout the intervention-period, and after a 4-week wash-out.

RESULTS

HbA1c-reductions were similar with exenatide (mean ± SEM -0.80 ± 0.10%) and iGlar (-0.79 ± 0.14%; treatment-difference 0.02%; 95% CI -0.31 to 0.42%). Change from baseline to Week-52 in CrCl, UAE or UACR did not statistically differ; only iGlar reduced albuminuria (P < 0.05; within-group). eGFR decreased from baseline to Week-4 with exenatide (-3.9 ± 2.1 mL/min/1.73 m²; P = 0.069) and iGlar (-2.7 ± 1.2 mL/min/1.73 m²; P = 0.034), without treatment-differences in ensuing trajectory. Exenatide versus iGlar reduced bodyweight (-5.4 kg; 2.9-7.9; P < 0.001), but did not affect blood pressure, lipids or plasma uric acid.

CONCLUSIONS

Among T2DM patients without overt nephropathy, one-year treatment with exenatide twice-daily does not affect renal function-decline or onset/progression of albuminuria compared to titrated iGlar.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00097500.

The incretin pathway as a therapeutic target in diabetic kidney disease: a clinical focus on GLP-1 receptor agonists

Diabetic kidney disease (DKD) remains the main cause for chronic kidney disease (CKD) and end-stage kidney disease (ESKD) worldwide. Both CKD and ESKD lead to major increases in risk of cardiovascular disease and death in people with diabetes. Despite optimal management of lifestyle, glucose levels and hypertension, residual risk remains high, indicating that additional therapies to mitigate the burden of the disease are desired. In past decades, new treatment options for the management of diabetes have emerged, of which some have showed promising renoprotective potential. This review discusses current understanding of the renal effects of glucagon-like peptide receptor agonists and their potential use in prevention and treatment of DKD.

Dulaglutide versus insulin glargine in patients with type 2 diabetes and moderate-to-severe chronic kidney disease (AWARD-7): a multicentre, open-label, randomised trial

BACKGROUND

Many antihyperglycaemic drugs, including insulin, are primarily cleared by the kidneys, restricting treatment options for patients with kidney disease. Dulaglutide is a long-acting glucagon-like peptide-1 receptor agonist that is not cleared by the kidneys, and confers a lower risk of hypoglycaemia than does insulin. We assessed the efficacy and safety of dulaglutide in patients with type 2 diabetes and moderate-to-severe chronic kidney disease.

METHODS

AWARD-7 was a multicentre, open-label trial done at 99 sites in nine countries. Eligible patients were adults with type 2 diabetes and moderate-to-severe chronic kidney disease (stages 3-4), with an HbA_1c of 7·5-10·5%, and who were being treated with insulin or insulin plus an oral antihyperglycaemic drug and were taking a maximum tolerated dose of an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Participants were randomly assigned (1:1:1) by use of a computer-generated random sequence with an interactive response system to once-weekly injectable dulaglutide 1·5 mg, once-weekly dulaglutide 0·75 mg, or daily insulin glargine as basal therapy, all in combination with insulin lispro, for 52 weeks. Insulin glargine and lispro doses were titrated as per an adjustment algorithm; dulaglutide doses were masked to participants and investigators. The primary outcome was HbA_1c at 26 weeks, with a 0·4% non-inferiority margin. Secondary outcomes included estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR). The primary analysis population was all randomly assigned patients who received at least one dose of study treatment and had at least one post-randomisation HbA_1c measurement. The safety population was all patients who received at least one dose of study treatment and had any post-dose data. This study is registered with ClinicalTrials.gov, number NCT01621178.

FINDINGS

Between Aug 15, 2012, and Nov 30, 2015, 577 patients were randomly assigned, 193 to dulaglutide 1·5 mg, 190 to dulaglutide 0·75 mg, and 194 to insulin glargine. The effects on HbA_1c change at 26 weeks of dulaglutide 1·5 mg and 0·75 mg were non-inferior to those of insulin glargine (least squares mean [LSM] -1·2% [SE 0·1] with dulaglutide 1·5 mg [183 patients]; -1·1% [0·1] with dulaglutide 0·75 mg [180 patients]; -1·1% [0·1] with insulin glargine [186 patients]; one-sided p≤0·0001 for both dulaglutide doses vs insulin glargine). The differences in HbA_1c concentration at 26 weeks between dulaglutide and insulin glargine treatments were LSM difference -0·05% (95% CI -0·26 to 0·15, p<0·0001) with dulaglutide 1·5 mg and 0·02% (-0·18 to -0·22, p=0·0001) with dulaglutide 0·75 mg. HbA_1c-lowering effects persisted to 52 weeks (LSM -1·1% [SE 0·1] with dulaglutide 1·5 mg; -1·1% [0·1] with dulaglutide 0·75 mg; -1·0% [0·1] with insulin glargine). At 52 weeks, eGFR was higher with dulaglutide 1·5 mg (Chronic Kidney Disease Epidemiology Collaboration equation by cystatin C geometric LSM 34·0 mL/min per 1·73 m² [SE 0·7]; p=0·005 vs insulin glargine) and dulaglutide 0·75 mg (33·8 mL/min per 1·73 m² [0·7]; p=0·009 vs insulin glargine) than with insulin glargine (31·3 mL/min per 1·73 m² [0·7]). At 52 weeks, the effects of dulaglutide 1·5 mg and 0·75 mg on UACR reduction were not significantly different from that of insulin glargine (LSM -22·5% [95% CI -35·1 to -7·5] with dulaglutide 1·5 mg; -20·1% [-33·1 to -4·6] with dulaglutide 0·75 mg; -13·0% [-27·1 to 3·9] with insulin glargine). Proportions of patients with any serious adverse events were similar across groups (20% [38 of 192] with dulaglutide 1·5 mg, 24% [45 of 190] with dulaglutide 0·75 mg, and 27% [52 of 194] with insulin glargine). Dulaglutide was associated with higher rates of nausea (20% [38 of 192] with dulaglutide 1·5 mg and 14% [27 of 190] with 0·75 mg, vs 5% [nine of 194] with insulin glargine) and diarrhoea (17% [33 of 192] with dulaglutide 1·5 mg and 16% [30 of 190] with 0·75 mg, vs 7% [14 of 194] with insulin glargine) and lower rates of symptomatic hypoglycaemia (4·4 events per patient per year with dulaglutide 1·5 mg and 4·3 with dulaglutide 0·75 mg, vs 9·6 with insulin glargine). End-stage renal disease occurred in 38 participants: eight (4%) of 192 with dulaglutide 1·5 mg, 14 (7%) of 190 with dulaglutide 0·75 mg, and 16 (8%) of 194 with insulin glargine.

INTERPRETATION

In patients with type 2 diabetes and moderate-to-severe chronic kidney disease, once-weekly dulaglutide produced glycaemic control similar to that achieved with insulin glargine, with reduced decline in eGFR. Dulaglutide seems to be safe to use to achieve glycaemic control in patients with moderate-to-severe chronic kidney disease.

FUNDING

Eli Lilly and Company.

Glycemic control of type 2 diabetes mellitus across stages of renal impairment: information for primary care providers

Chronic kidney disease (CKD) is a frequent complication of type 2 diabetes mellitus (T2DM) and elevates individuals' risk for cardiovascular disease, the leading cause of morbidity and mortality in T2DM. Achieving and maintaining tight glycemic control is key to preventing development or progression of CKD; however, improving glycemic control may be limited by effects of renal impairment on the efficacy and safety of T2DM treatments, necessitating dosing adjustments and careful evaluation of contraindications. Understanding the treatment considerations specific to each class of T2DM medication is important in individualizing therapy and improving glycemic, renal, and cardiovascular outcomes. Traditional glucose-lowering treatments include insulin, metformin, sulfonylureas, meglitinides, and thiazolidinediones. Each of these agents exhibits altered pharmacokinetics in patients with renal impairment except for the thiazolidinediones, which are metabolized by the liver and do not accumulate appreciably in patients with renal impairment. Newer glucose-lowering treatments include GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors. Of these, only the DPP-4 inhibitor linagliptin can be used across all stages of renal impairment without dosing restrictions or concerns regarding dose escalation, and all SGLT2 inhibitors are contraindicated when eGFR <45 mL/min/1.73m². Several of the newer treatments have also been investigated for effects on renal and cardiovascular outcomes, demonstrating potential benefits of the GLP-1 agonists liraglutide and semaglutide, as well as the SGLT2 inhibitors canagliflozin and empagliflozin, in reducing risk for some adverse renal and cardiovascular events. In addition, some DPP-4 inhibitors have been shown to reduce albuminuria, an indicator of glomerular dysfunction. Consideration of this information is useful in informing optimal management strategies for patients with T2DM and concomitant CKD. More clinical data from future and ongoing clinical trials, including data regarding potential renal and cardiovascular benefits, will be important in clarifying the safety and efficacy profiles of each of these agents in patients with CKD.

GLP-1 and the kidney: from physiology to pharmacology and outcomes in diabetes

The gastrointestinal tract - the largest endocrine network in human physiology - orchestrates signals from the external environment to maintain neural and hormonal control of homeostasis. Advances in understanding entero-endocrine cell biology in health and disease have important translational relevance. The gut-derived incretin hormone glucagon-like peptide 1 (GLP-1) is secreted upon meal ingestion and controls glucose metabolism by modulating pancreatic islet cell function, food intake and gastrointestinal motility, amongst other effects. The observation that the insulinotropic actions of GLP-1 are reduced in type 2 diabetes mellitus (T2DM) led to the development of incretin-based therapies - GLP-1 receptor agonists and dipeptidyl peptidase 4 (DPP-4) inhibitors - for the treatment of hyperglycaemia in these patients. Considerable interest exists in identifying effects of these drugs beyond glucose-lowering, possibly resulting in improved macrovascular and microvascular outcomes, including in diabetic kidney disease. As GLP-1 has been implicated as a mediator in the putative gut-renal axis (a rapid-acting feed-forward loop that regulates postprandial fluid and electrolyte homeostasis), direct actions on the kidney have been proposed. Here, we review the role of GLP-1 and the actions of associated therapies on glucose metabolism, the gut-renal axis, classical renal risk factors, and renal end points in randomized controlled trials of GLP-1 receptor agonists and DPP-4 inhibitors in patients with T2DM.

Therapeutic Considerations for Antihyperglycemic Agents in Diabetic Kidney Disease

Diabetic kidney disease is among the most frequent complications of diabetes, with approximately 50% of patients with ESRD attributed to diabetes in developed countries. Although intensive glycemic management has been shown to delay the onset and progression of increased urinary albumin excretion and reduced GFR in patients with diabetes, conservative dose selection and adjustment of antihyperglycemic medications are necessary to balance glycemic control with safety. A growing body of literature is providing valuable insight into the cardiovascular and renal safety and efficacy of newer antihyperglycemic medications in the dipeptidyl peptidase-4 inhibitor, glucagon-like peptide-1 receptor agonist, and sodium-glucose cotransporter 2 inhibitor classes of medications. Ongoing studies will continue to inform future use of these agents in patients with diabetic kidney disease.

Exenatide: pharmacokinetics, clinical use, and future directions

INTRODUCTION

The first-in-class glucagon-like peptide-1 receptor agonist (GLP-1RA) exenatide, which was initially approved in 2005, is available in twice-daily (BID) and once-weekly (QW) formulations. Clinical trial data suggest both formulations are effective and safe for patients with type 2 diabetes (T2D), both as monotherapy and as part of combination therapy. Since exenatide was approved, several other GLP-1RAs have become available for clinical use. Areas covered: Many ongoing clinical trials involving exenatide BID and exenatide QW are investigating new indications (exenatide BID) and new end points and combination therapies (exenatide QW). This review provides an overview of the delivery and pharmacokinetics of both formulations of exenatide, reviews existing data in T2D, and summarizes ongoing investigations. Expert opinion: Exenatide BID and QW have substantial clinical benefits. Comparisons with other GLP-1RAs demonstrate some differences in efficacy and safety profiles that make assessment of benefit:risk ratios complex. Head-to-head comparisons of QW GLP-1RA formulations may assist in the ranking of GLP-1RAs according to efficacy and safety. Results on the impact of exenatide QW on cardiovascular outcomes are eagerly awaited. The potential clinical utility of exenatide BID in other indications will clarify whether exenatide holds clinical promise in diagnoses other than T2D.

Effects of once-weekly dulaglutide on kidney function in patients with type 2 diabetes in phase II and III clinical trials

Dulaglutide is a once-weekly glucagon-like peptide-1 receptor agonist approved for the treatment of type 2 diabetes (T2D). Integrated data from 9 phase II and III trials in people with T2D (N = 6005) were used to evaluate the effects of dulaglutide on estimated glomerular filtration rate (eGFR [Chronic Kidney Disease Epidemiology Collaboration]), urine albumin-to-creatinine ratio (UACR) and kidney adverse events (AEs). No significant differences in eGFR were observed during treatment for dulaglutide vs placebo, active comparators or insulin glargine (mean ± standard deviation values: dulaglutide vs placebo: 87.8 ± 17.7 vs 88.2 ± 17.9 mL/min/1.73 m² , P = .075; dulaglutide vs active comparators: 89.9 ± 16.7 vs 88.8 ± 16.3 mL/min/1.73 m² , P = .223; and dulaglutide vs insulin glargine: 85.9 ± 18.2 vs 83.9 ± 18.6 mL/min/1.73 m² , P = .423). Lower UACR values were observed for dulaglutide vs placebo, active comparators and insulin glargine (at 26 weeks, median [Q1-Q3] values were: dulaglutide vs placebo: 8.0 [4.4-20.4] vs 8.0 [4.4-23.9] mg/g, P = .023; dulaglutide vs active comparators: 8.0 [4.4-21.2] vs 8.9 [4.4-27.4] mg/g, P = .013; and dulaglutide vs insulin glargine: 8.9 [4.4-29.2] vs 12.4 [5.3-50.5] mg/g, P = .029). AEs reflecting potential acute renal failure were 3.4, 1.7 and 7.0 events/1000 patient-years for dulaglutide, active comparators and placebo, respectively. In conclusion, dulaglutide treatment of clinical trial participants with T2D did not affect eGFR and slightly decreased albuminuria.

Renal Effects of DPP-4 Inhibitor Sitagliptin or GLP-1 Receptor Agonist Liraglutide in Overweight Patients With Type 2 Diabetes: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

To investigate effects of dipeptidyl peptidase-4 inhibitor (DPP-4I) sitagliptin or glucagon-like peptide 1 (GLP-1) receptor agonist liraglutide treatment on renal hemodynamics, tubular functions, and markers of renal damage in overweight patients with type 2 diabetes without chronic kidney disease (CKD).

RESEARCH DESIGN AND METHODS

In this 12-week, randomized, double-blind trial, 55 insulin-naïve patients with type 2 diabetes (mean ± SEM: age 63 ± 7 years, BMI 31.8 ± 4.1 kg/m², glomerular filtration rate [GFR] 83 ± 16 mL/min/1.73 m²; median [interquartile range]: albumin-to-creatinine ratio (ACR) 1.09 mg/mmol [0.47-3.31]) received sitagliptin (100 mg/day), liraglutide (1.8 mg/day), or matching placebos. GFR (primary end point) and effective renal plasma flow (ERPF) were determined by inulin and para-aminohippuric acid clearance, respectively. Intrarenal hemodynamic variables were estimated. Absolute and fractional excretions of sodium (FE_Na), potassium, and urea (FE_U) and renal damage markers (ACR, neutrophil gelatinase-associated lipocalin [NGAL], and kidney injury molecule-1 [KIM-1]) were measured. Plasma renin concentration (PRC) and glycated hemoglobin (HbA_1c) were assessed. At weeks 2 and 6, estimated GFR and fractional electrolyte excretions were determined.

RESULTS

At week 12, GFR was not affected by sitagliptin (-6 mL/min/1.73 m² [95% CI -14 to 3], P = 0.17) or liraglutide (+3 mL/min/1.73 m² [-5 to 11], P = 0.46), compared with placebo. Sitagliptin modestly reduced estimated glomerular hydraulic pressure (P_GLO; P = 0.043). ERPF, other intrarenal hemodynamic variables, renal damage markers, and PRC did not change for both treatments. Both agents reduced HbA_1c. Only at week 2, sitagliptin increased FE_Na and FE_U (P = 0.005).

CONCLUSIONS

Twelve-week treatment with sitagliptin or liraglutide does not affect measured renal hemodynamics. No sustained changes in tubular functions or alteration in renal damage markers were observed. The validity and clinical relevance of the slight sitagliptin-induced P_GLO reduction remains speculative.

Exenatide Extended-Release: An Updated Review of Its Use in Type 2 Diabetes Mellitus

Exenatide extended-release (exenatide ER) [Bydureon(®)] is a glucagon-like peptide-1 receptor agonist, approved for the treatment of type 2 diabetes mellitus. It is injected subcutaneously by patients once weekly, with no dose titration required. This article updates an earlier review of exenatide ER in the management of type 2 diabetes, focusing on recently published data. In randomized, controlled trials, adjunctive exenatide ER 2 mg once weekly for 24-30 weeks significantly improved glycaemic control and reduced bodyweight in patients with inadequately controlled type 2 diabetes despite diet plus exercise and/or oral antihyperglycaemic drugs (OADs). These beneficial effects of exenatide ER were maintained after up to 6 years of treatment. In patients receiving one or more OADs, addition of exenatide ER provided better glycaemic control than an immediate-release formulation of exenatide (exenatide twice daily), sitagliptin, pioglitazone, insulin glargine or insulin detemir, and was slightly less effective than liraglutide. In patients treated with diet plus exercise alone, adjunctive exenatide ER was noninferior to metformin and superior to sitagliptin, but was not noninferior to pioglitazone. Exenatide ER was generally well tolerated, with a low inherent risk of hypoglycaemia. The most common adverse events were mild to moderate gastrointestinal events, injection-site reactions and headache. Thus, exenatide ER is a useful treatment option in the management of type 2 diabetes. It offers a convenient, once-weekly regimen and can be administered by patients via a pen injection system or syringes and needles.

Incretin-based therapy: renal effects

Glucagon like peptide-1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors are new classes of hypoglycemic agents with numerous pleiotropic effects. The review summarises data about the influence of GLP-1 analogues and DPP-4 inhibitors on structural and functional changes in diabetic kidneys. Growing evidence indicates that the kidney is one of the loci of the effects and degradation of GLP-1. The potency of the effects of GLP-1 in diabetic kidneys can be reduced by decrease in GLP-1 receptor expression or enhancement of GLP-1 degradation. In experimental models of diabetic nephropathy and non-diabetic renal injury, GLP-1 analogues and DPP-4 inhibitors slow the development of kidney fibrosis and prevent the decline of kidney function. The mechanisms of protective effect include hyperglycaemia reduction, enhancement of sodium excretion, suppression of inflammatory and fibrogenic signalling pathways, reduction of oxidative stress and apoptosis in the kidneys. In clinical studies, the urinary albumin excretion reduction rate while using the GLP-1 analogue and DPP-4 inhibitor treatment was demonstrated in patients with type 2 diabetes. Long-term impact of these agents on renal function in diabetes needs further investigations.

Emerging utility of once-weekly exenatide in patients with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a major risk factor for the development of cardiovascular disease (CVD). Due to the ever increasing incidence of both T2DM and CVD and coexistence of these disorders, numerous agents have been developed over the years to target complications. We focus on the efficacy and safety perspective of a long-acting formulation of the glucagon-like peptide-1 analog exenatide. Our review focuses on the various landmark trials, efficacy, safety profile, and patient perspectives of weekly exenatide that delineates its current and future role in the treatment of patients with T2DM and CVD.

Exenatide twice daily: a review of its use in the management of patients with type 2 diabetes mellitus

Exenatide, administered subcutaneously twice daily (Byetta(®)), is a synthetic version of the natural peptide exendin-4, which is a glucagon-like peptide-1 (GLP-1) receptor agonist (incretin mimetic). Exenatide binds to the GLP-1 receptor with the same affinity as GLP-1, but has a much longer half-life, since it is not degraded by the enzyme dipeptidyl peptidase-4. Exenatide twice daily enhances glucose-dependent insulin secretion, suppresses inappropriately elevated glucagon secretion, slows gastric emptying and reduces caloric intake. In well-designed clinical trials, adjunctive subcutaneous exenatide 5 or 10 μg twice daily for 16-52 weeks significantly and dose-dependently improved glycaemic control and reduced mean body weight compared with placebo in patients with type 2 diabetes inadequately controlled with oral antihyperglycaemic drugs (OADs) and/or basal insulin. The improvements in glycaemic control and reductions in body weight were stably maintained during long-term therapy (up to 3.5 years). The efficacy of adjunctive exenatide twice daily was generally similar to that of basal, prandial or biphasic insulin, sulfonylureas, rosiglitazone and lixisenatide, and less than that of liraglutide, taspoglutide or exenatide once weekly with respect to reductions in glycated haemoglobin. Exenatide twice daily was generally well tolerated; mild to moderate nausea and vomiting, which decreased with time on therapy, were the most common adverse events. In patients not receiving concomitant sulfonylureas or insulin, the incidence of hypoglycaemia was low; when it did occur, it was generally mild in severity. Thus, adjunctive exenatide twice daily is a valuable option in the treatment of type 2 diabetes inadequately controlled with OADs and/or basal insulin.

Safety and tolerability of exenatide once weekly in patients with type 2 diabetes: an integrated analysis of 4,328 patients

BACKGROUND

Exenatide once weekly (QW) is a glucagon-like peptide-1 receptor agonist (GLP-1RA) for the treatment of type 2 diabetes. Safety and tolerability are key considerations in treatment selection. This analysis examines the safety and tolerability profile of exenatide QW, other approved GLP-1RAs (exenatide twice daily and liraglutide once daily), and a pooled population of commonly used non-GLP-1RA treatments.

METHODS

Intent-to-treat populations from eight randomized Phase III trials with 24-week and 30-week comparator-controlled periods were analyzed. Data were pooled for exenatide QW, exenatide twice daily, and non-GLP-1RA comparator groups; comparisons between exenatide QW and liraglutide were analyzed separately to better match study groups. The incidence of treatment-emergent adverse events with 95% confidence intervals and exposure-adjusted incidence were calculated. Duration and recurrence were analyzed for gastrointestinal adverse events and adverse events of special interest.

RESULTS

Incidences of serious adverse events did not differ between treatments. Discontinuations due to adverse events occurred numerically less frequently with exenatide QW than with other GLP-1RAs but numerically more frequently than with non-GLP-1RA comparators. The most frequent adverse events in the GLP-1RA groups were gastrointestinal and generally mild, with decreasing incidence over time. Gastrointestinal adverse event incidences appeared lower with exenatide QW versus other GLP-1RAs and greater than with non-GLP-1RA comparators. Injection site-related adverse events seemed highest with exenatide QW, but generally did not lead to withdrawal and abated over time. Hypoglycemia was infrequent overall, but occurred numerically more frequently in the non-GLP-1RA comparator group and increased with concomitant sulfonylurea use. Pancreatitis, thyroid cancer, renal failure, and gallbladder disease were rarely reported.

CONCLUSION

The overall safety and tolerability profile of exenatide QW was similar to that of other GLP-1RAs, with improved gastrointestinal tolerability. The safety and tolerability profile of exenatide QW compared with non-GLP-1RA comparators was similar overall, with the exception of a lower incidence of hypoglycemia and anticipated differences in gastrointestinal and injection site-related adverse events.

Diabetic kidney disease: a report from an ADA Consensus Conference

The incidence and prevalence of diabetes mellitus have grown significantly throughout the world, due primarily to the increase in type 2 diabetes. This overall increase in the number of people with diabetes has had a major impact on development of diabetic kidney disease (DKD), one of the most frequent complications of both types of diabetes. DKD is the leading cause of end-stage renal disease (ESRD), accounting for approximately 50% of cases in the developed world. Although incidence rates for ESRD attributable to DKD have recently stabilized, these rates continue to rise in high-risk groups such as middle-aged African Americans, Native Americans, and Hispanics. The costs of care for people with DKD are extraordinarily high. In the Medicare population alone, DKD-related expenditures among this mostly older group were nearly $25 billion in 2011. Due to the high human and societal costs, the Consensus Conference on Chronic Kidney Disease and Diabetes was convened by the American Diabetes Association in collaboration with the American Society of Nephrology and the National Kidney Foundation to appraise issues regarding patient management, highlighting current practices and new directions. Major topic areas in DKD included 1) identification and monitoring, 2) cardiovascular disease and management of dyslipidemia, 3) hypertension and use of renin-angiotensin-aldosterone system blockade and mineralocorticoid receptor blockade, 4) glycemia measurement, hypoglycemia, and drug therapies, 5) nutrition and general care in advanced-stage chronic kidney disease, 6) children and adolescents, and 7) multidisciplinary approaches and medical home models for health care delivery. This current state summary and research recommendations are designed to guide advances in care and the generation of new knowledge that will meaningfully improve life for people with DKD.

Evidence-based practice use of incretin-based therapy in the natural history of diabetes

The incretin class of anti-hyperglycemic agents, including glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-inhibitors, is an important addition to the therapeutic armamentarium for the management of appropriate patients with type 2 diabetes mellitus as an adjunct to diet and exercise and/or with the agents metformin, sulfonylureas, thiazolidinediones, or any combination thereof. More recently, US Food and Drug Administration (FDA)-approved indications for incretins were expanded to include use with basal insulin. This review article takes an evidence-based practice approach in discussing the importance of aggressive treatment for diabetes, the principles of incretin physiology and pathophysiology, use of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, and patient types and contexts where incretin therapy has been found beneficial, from metabolic syndrome to overt diabetes.

Pathophysiological and pharmacological rationale for the use of exenatide once weekly in patients with type 2 diabetes

INTRODUCTION

A new formulation of exenatide has become available recently that is the first antidiabetic medication for type 2 diabetes mellitus (T2DM) dosed on a weekly schedule. This review summarizes the pharmacology, efficacy, and safety of exenatide once weekly (exenatide QW). The results are interpreted in terms of the pathophysiology of T2DM, as well as the pharmacology of the new formulation.

METHODS

Relevant literature on exenatide QW and diabetes was identified through PubMed database searches from inception until September 2013.

DISCUSSION

In the new once-weekly formulation of exenatide, the exenatide molecule is dispersed in microspheres. Following subcutaneous injection, these microspheres degrade in situ and slowly release active agent. In clinical trials, therapy with exenatide QW as monotherapy or in combination with other antidiabetic treatments was associated with reductions in glycated hemoglobin (-1.3% to -1.9%), fasting plasma glucose (-32 to -41 mg/dL), and body weight (-2.0 to -3.7 kg). These outcomes were achieved without an associated increase in the rate of hypoglycemic episodes, except when exenatide QW was used in combination with sulfonylureas. The primary tolerability issues in the trials were gastrointestinal adverse events, particularly during the first weeks of use, although the rate of nausea during startup with exenatide QW was lower than that with the related agents, exenatide twice daily and liraglutide once daily.

CONCLUSIONS

Exenatide QW may be particularly well suited to patients who desire the benefits associated with glucagon-like peptide-1 receptor agonists, including significant glycemic control, low risk of hypoglycemia, and moderate weight loss, but prefer the convenience of once-weekly dosing.