Sgemaglutide in type 2 diabetes – is it the best glucagon-like peptide 1 receptor agonist (GLP-1R agonist)?

Introduction: Glucagon-like peptide-1 (GLP-1) is produced by the gut, and in a glucose-dependent manner stimulates insulin secretion while inhibiting glucagon secretion, reduces appetite and energy intake, and delays gastric emptying. The GLP-1R agonist semaglutide has recently been registered to treat type 2 diabetes.

Area covered: This review is of semaglutide in type 2 diabetes, and considers which properties of this GLP-1R agonist, may be responsible for its clinical outcome benefits .

Expert opinion: The pharmacokinetics of semaglutide make it ideal for once-weekly dosing. SUSTAIN 6 (Trial to Evaluate Cardiovascular and Other Long-term Outcomes With Semaglutide in Subjects With Type 2 Diabetes) showed that semaglutide 0.5 or 1 mg subcutaneously once-weekly reduced cardiovascular outcomes in subjects with type 2 diabetes and cardiovascular disease or risk, mean age 65 years, baseline HbA1c 8.7% and mean body weight of 92 kg. Although, semaglutide may be a useful drug in this population, it increased retinopathy to a small extent and this needs further investigation. Also, it is not known whether semaglutide will improve cardiovascular outcomes in other populations including those with lower ages, HbA1c values, and body weights similar to those included in the unsuccessful clinical outcome trials with the GLP-1R agonists, lixisenatide and exenatide.     

A comparative safety review between GLP-1 receptor agonists and SGLT2 inhibitors for diabetes treatment

Introduction: Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium glucose cotransporter 2 inhibitors (SGLT2i) are of particular interest in type 2 diabetes treatment strategies, due to their efficacy in reducing HbA1c with a low risk of hypoglycaemia, to their positive effects on body weight and blood pressure and in light of their effects on cardiovascular risk and on nephroprotection emerged from the most recent cardiovascular outcome trials.

Since it is therefore very likely that GLP-1RA and SGLT2i use will become more and more common, it is more and more important to gather and discuss information about their safety profile.

Area Covered: adverse events and the safety concerns most often emerged in trials with GLP-1RA namely, exenatide long acting release (LAR), dulaglutide, liraglutide, semaglutide, lixisenatide or SGLT2i, namely empagliflozin, dapagliflozin, canagliflozin and SGLT2i with an attempt at comparing the safety profiles of molecules of these two classes.

Expert opinion: GLP-1RA and SGLT2i, although each associated with different specific side effects, share a ‘similar’ safety profile and are both drugs relatively easy to handle. The potentially complementary mechanisms of action, the cardio and nephroprotective effects demonstrated by molecules of both classes, make these drugs potentially useful even in add on to each other.     

Individualized,patient-centered use of lixisenatide for the treatment of type 2 diabetes mellitus

Introduction: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease associated with hyperglycemia, which can lead to serious vascular complications. Current treatment guidelines place particular emphasis on personalization of therapy. Within this guidance, the use of various second-line therapies, including glucagon-like peptide-1 receptor agonists (GLP-1 RAs), is recommended under certain circumstances.

Areas covered: Factors influencing glucose homeostasis, including gastric emptying and the associated cardiovascular (CV) risk when homeostasis is not maintained, are reviewed. Physiology relating to the mechanism of action of GLP-1 RAs is summarized, with a particular focus on lixisenatide. In addition, an overview of efficacy and safety data for lixisenatide is presented and the CV effects of GLP-1 RAs are examined. Finally, the rationale and clinical data supporting the combination of lixisenatide and basal insulin are explored.

Expert opinion: GLP-1 analogs meet a need for better glycemic control, with the added benefits of reduced hypoglycemic risk and body weight. The combination of a short-acting GLP-1 RA, such as lixisenatide, with a basal insulin, exploits the complementary effects of both of these therapies and seems well suited for the treatment of T2DM. However, further studies are needed to establish the associated CV risks and/or benefits of GLP-1 RAs.     

Efficacy and safety of once-weekly semaglutide for the treatment of type 2 diabetes

Introduction: Type 2 diabetes is a chronic metabolic disease characterized by persistent hyperglycemia resulting from progressive deficient of insulin in patients with a background of insulin resistance. Current treatment algorithms recommended by American Diabetes Association/The European Association for the Study of Diabetes promote a patient-centered approach that takes into account a comprehensive consideration of pharmacological properties of drugs, including glucose-lowering action, effects on body weight, correction on multiple pathophysiologic defects, tolerability, and long-term safety. Glucagon-likepeptide1 (GLP-1) receptor analogues are appealing due to the improved glycemic control in a glucose-dependent manner, modest weight loss and low risk of hypoglycemia.

Areas covered: Semaglutide (Novo Nordisk), a once-weekly GLP-1 analogue, is currently in the phase III clinical trial for the treatment of type 2 diabetes. This article aims to review the pharmacological and clinical profiles of semaglutide based on the available clinical data.

Expert opinion: Semaglutide achieved greater reduction from baseline in HbA_1c in comparison to placebo. The greater proportion of patients in semaglutide group than that in placebo group achieved target HbA_1c <7.0% and <6.5%, respectively. Semaglutide is the second GLP-1 analogue contributing to the reduced bodyweight and improving obesity related complications. More importantly, semaglutide is beneficial to diabetic patients with high cardiovascular risk according to the recently completed phase III trial. The incidence of gastrointestinal adverse effects increased with semaglutide dose.     

Cardiovascular safety of therapies for type 2 diabetes

Introduction: Dipeptidyl peptidase-4 (DPP4) inhibitors, glucagon-like peptide-1 (GLP-1) analogs and sodium-glucose cotransporter 2 (SGLT2) inhibitors are relatively new therapies for the treatment of type 2 diabetes mellitus. Given the high prevalence of cardiovascular complications in patients with type 2 diabetes and recent concerns questioning CV safety of newer antidiabetic medications, cardiovascular safety of these medications requires evaluation.

Areas covered: Cardiovascular effects of these drug classes from preclinical and clinical data as well as non-cardiovascular safety issues are delineated from literature searches covering the last decade and up to June 2016. Major clinical trials assessing the cardiovascular safety of GLP-1 agonists (ELIXA and LEADER), DPP-4 inhibitors (SAVOR-TIMI 53, EXAMINE, and TECOS) and SGLT2 inhibitors (EMPA-REG OUTCOME) are reviewed and interpreted.

Expert opinion: Based on review of the present evidence, these 3 classes of antihyperglycemic therapies have acceptably safe CV safety profiles for patients with type 2 diabetes. The latest evidence from LEADER and EMPA-REG OUTCOME trials indicate that liraglutide and empagliflozin have cardiovascular benefits that may prove to be of clinical importance in the management of type 2 DM.     

Safety and tolerability of glucagon-like peptide-1 receptor agonists: unresolved and emerging issues

Introduction: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a mainstay of treatment options for type 2 diabetes. They contribute to lowering blood glucose levels, generally have a favorable tolerability profile, and can be used alone or in combination with other antidiabetic agents. Based on the duration of their effects, GLP-1 RAs can be divided into two classes: short-acting and long-acting. Differences exist between these sub-classes, and between each drug, in terms of pharmacokinetic and pharmacodynamic profiles. Therefore, prescribers cannot necessarily assume GLP-1 RA ‘class effects’, especially in terms of tolerability.

Areas covered: This article reviews the published data on the safety and tolerability of currently available GLP-1 RAs and, recognizing the importance of safety profiles when selecting the appropriate treatment for each patient, examines the clinical implications of the differences between the drugs in this class. Cardiovascular safety, gastrointestinal tolerability, and tolerability in elderly patients are discussed as specific areas of interest to prescribers selecting between GLP-1 RAs for their patients.

Expert opinion: Although further research is needed, the current evidence offers the potential to tailor treatment more accurately to each patient. Ultimately, this may improve adherence and persistence, thereby improving glycemic control and, in turn, reducing the risk of macro- and micro-vascular complications.     

Cardiovascular safety of liraglutide for the treatment of type 2 diabetes

Introduction: Liraglutide is a GLP-1 RA that is an option for treatment of T2DM. Typical of all new glucose-lowering agents, its CV safety profile is of great interest.

Areas covered: This article outlines the efficacy of the GLP-1 RA liraglutide from RCTs, moving through the pivotal phase 3 LEAD trials, and subsequent meta-analyses to assess CV safety. This review describes evolution of regulatory requirements to obtain safety information through dedicated CVOTs.

Expert opinion: Since the FDA mandated that CV outcomes for new diabetes therapies should be assessed via a dedicated CVOT, opinion of their utility in T2DM evolved from cynicism through to enthusiasm. In LEADER, liraglutide became the second modern glucose-lowering agent to demonstrate significant CV benefit. CVOTs are now providing important answers, highlighting the CV benefits of modern glucose-lowering agents, but also raising several questions, notably whether the effects seen with liraglutide and empagliflozin are class-effects or are unique to these molecules. Furthermore it is unknown if these results in patients with high CV risk are applicable to all patients with T2DM, and should be incorporated into new treatment guidelines. In our view it’s prudent to suggest that CVOT findings cannot currently be extrapolated to the whole T2DM population.     

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.     

The efficacy and safety of exenatide once weekly in patients with type 2 diabetes

Introduction: Exenatide once weekly (QW) is a glucagon-like peptide 1 receptor agonist (GLP-1RA) that was approved in 2012 in Europe and the U.S.A. for the treatment of type 2 diabetes (T2D).

Areas covered: This review provides an overview of the safety and efficacy of exenatide QW for the treatment of T2D and evaluates the benefit–risk ratio compared to other available long-acting GLP-1RAs. In addition, the authors provide an outline of the novel formulations and delivery methods of exenatide.

Expert opinion: Exenatide QW is an efficacious and safe treatment for T2D. However, head-to-head trials have demonstrated exenatide QW to be inferior to liraglutide and semaglutide with respect to effects on fasting plasma glucose, glycated hemoglobin A1c, and bodyweight. In addition, exenatide QW appears inferior to liraglutide and semaglutide in terms of cardiovascular risk reduction. Currently, the overall risk-benefit profiles for the range of GLP-1RAs point to liraglutide and semaglutide as first-choice for the management of T2D, which has been confirmed by a recently published consensus report on the treatment of T2D from the American Diabetes Association and the European Association for the Study of Diabetes. The pricing of exenatide QW will most likely be a key determinant for its place in the future management of T2D.     

Adding prandial GLP-1 receptor agonists to basal insulin: a promising option for type 2 diabetes therapy

Background: Diabetes mellitus is a serious and increasingly prevalent condition in Canada and around the world. Treatment strategies have become increasingly complex, with a widening array of pharmacological agents available for glycemic management in type 2 diabetes mellitus (T2DM). New therapies that act in concert with available basal insulins may represent alternatives to basal insulin intensification with prandial or pre-mixed insulin. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have recently shown promise as useful additions to basal insulin, with significant reductions in glycated hemoglobin and potentially beneficial effects on body weight. This review will focus on pivotal clinical trials to assess the potential benefits of adding prandial GLP-1 RAs to basal insulin in patients with T2DM.

Methods: Clinical studies combining prandial GLP-1 RAs and basal insulin (published between 2011 and July 2017) were identified and reviewed in PubMed, the Cochrane Central Register of Clinical Trials (Issue 6, June 2017), and clinicaltrials.gov.

Results: Most of the studies presented in this review show that the addition of a prandial GLP-1 RA to basal insulin results in equal or slightly superior efficacy compared to the addition of prandial insulin, together with weight loss and less hypoglycemia.

Conclusions: The results of the studies suggest that a prandial GLP-1 RA as an add-on to basal insulin may be a safe and effective treatment intensification option (vs basal-plus or basal-bolus insulin).     

The safety of albiglutide for the treatment of type 2 diabetes

Introduction: Albiglutide is a marketed long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection. It has significantly less gastrointestinal side effects than other GLP-1 RAs in current use but does not improve HbA1c or promote weight loss to the same extent as competitor agents such as liraglutide.

Area Covered: The safety of albiglutide is discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents.

Expert Opinion: Unlike competitor agents, the gastrointestinal side effects of albiglutide are not much greater than placebo. It has been studied and appears safe at all stages of renal failure. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long term study now underway will determine if albiglutide, with its relatively favorable GI tolerance, has a place in the treatment of patients with increased risk of cardiovascular events.     

Non-insulin pharmacological therapies for treating type 1 diabetes

Introduction: Despite intensified insulin treatment, many persons with type 1 diabetes (T1D) do not achieve glycemic and metabolic targets. Consequently, non-insulin chemical therapies that improve glycemic control and metabolic parameters without increasing the risk of adverse events (including hypoglycemia) are of interest as adjunct therapies to insulin.

Areas covered: In this review, the authors discuss the efficacy and safety of non-insulin therapies, including pramlintide, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 inhibitors (DPP-4), sodium-glucose cotransporter (SGLT1 and SGLT2) inhibitors, metformin, sulfonylureas, and thiazolidinediones as add-on therapies to insulin in T1D.

Expert opinion: The current evidence shows that the efficacy of non-insulin therapies as add-on therapies to insulin is minimal or modest with an average HbA1c reduction of 0.2–0.5% (2–6 mmol/mol). Indeed, the current focus is on the development of SGLT inhibitors as adjuncts to insulin in type 1 diabetes. Studies of subgroups with obesity, residual beta-cell function (including newly diagnosed patients) and patients prone to hypoglycemia could be areas of future research.     

Preventing and treating kidney disease in patients with type 2 diabetes

Introduction: Chronic kidney disease (CKD) represents a huge burden in patients with type 2 diabetes (T2DM). This review therefore has the aim of assessing the add-on value of new glucose-lowering agents compared or combined with inhibitors of the renin angiotensin aldosterone system (RAAS) on renal outcomes in T2DM patients.

Areas covered: This article first summarizes the results reported with RAAS inhibitors, mainstay of nephroprotection in T2DM with albuminuria. Second, it describes the positive results with glucagon-like peptide-1 receptor agonists (GLP-1RAs) and, even more impressive, sodium-glucose cotransporter type 2 inhibitors (SGLT2is). Third, besides the potential of combined therapies, it briefly considers some new approaches currently in development.

Expert opinion: RAAS inhibitors exert renoprotective effects beyond their blood pressure lowering effects while SGLT2is, and possibly GLP-1RAs, exert nephroprotection independently of their glucose-lowering activity. These effects were demonstrated not only on surrogate endpoints such as albuminuria and estimated glomerular filtration rate decline, but also on hard endpoints, including progression to end-stage renal disease requiring replacement therapy. The underlying mechanisms are different and potentially complementary on glomerular hemodynamics, arguing for combined therapies. Nevertheless, there is still room for new emerging drugs to tackle CKD in T2DM.     

Cardiovascular disease prevention strategies for type 2 diabetes mellitus

Introduction: Type 2 diabetes mellitus (T2DM) is associated with several cardiovascular (CV) risk factors such as insulin resistance, obesity, hypertension, dyslipidaemia, non-alcoholic fatty liver disease as well as platelet and haemostatic abnormalities increasing the risk of thrombosis. Therefore, T2DM patients are at an increased risk for CV disease (CVD).

Areas covered: This narrative review discusses the treatment of T2DM. This includes lifestyle measures (diet, exercise and smoking cessation) as well as hypolipidaemic, antihypertensive, weight reducing, antiplatelet and glucose lowering drugs. The focus is on the effects of these therapeutic strategies on CVD risk. Randomized controlled clinical trials (RCTs) reporting CVD outcomes with such drugs in T2DM patients are also reviewed.

Expert opinion: Apart from current guidelines, the findings of RCTs on CVD outcomes in T2DM patients should be taken into consideration in daily clinical practice. Multiple risk factors should be targeted simultaneously in such high-risk patients in order to efficiently reduce the risk of CV events.     

Pharmacological management of diabetes in severe mental illness: a comprehensive clinical review of efficacy,safety and tolerability

Introduction: The increased prevalence of Type 2 diabetes mellitus (T2DM) in severe mental illness (SMI) contributes to increased cardiovascular morbidity and reduced life expectancy for people with SMI.

Areas covered: In the present clinical review, we summarize the efficacy, safety and tolerability of selected diabetic pharmacotherapy options in SMI and discuss the quality and strength of evidence.

Expert commentary: General principles for treating T2DM in SMI involve identifying treatments which promote weight loss and which have low or no risk of hypoglycemia. Patient engagement in decision making about treatment choices is an important factor to ensure adherence and successful use of the chosen therapy. The first line therapeutic option for T2DM in SMI for which there is most evidence is metformin. Based on general population data, second line treatment options in combination with metformin to achieve glycated haemoglobin treatment goals include GLP-1R agonists, DPP-4 inhibitors, sulphonylureas, SGLT2 inhibitors, pioglitazone and insulin, with most evidence for the use of GLP-1R agonists in SMI. Alongside efficacy and tolerability, treatment for T2DM in SMI should be considered on a patient-tailored basis.     

Efficacy and safety of fixed-ratio combination of insulin degludec and liraglutide (IDegLira) for the treatment of type 2 diabetes

Introduction: Type 2 diabetes (T2D) is a progressive disease with increasing prevalence in most countries. The majority of patients with T2D have inadequate glycaemic control, which increases the risk of diabetic complications later in life. New therapies with improved safety profiles are required to tackle the progressive nature of T2D.

Areas covered: The efficacy and safety profile of IDegLira – a once-daily, fixed-ratio combination of insulin degludec and liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), for the treatment of T2D – has been extensively evaluated. IDegLira’s phase 3 clinical trial programme builds upon the clinical programmes of its mono-components, and their cardiovascular outcomes trials. The results are described here, focusing on different patient populations and compared with alternative insulin regimens.

Expert opinion: IDegLira provides superior glycaemic control and mitigates the primary adverse effects associated with insulin therapy (weight gain and hypoglycaemia) and GLP-1RAs (gastrointestinal side effects) with no indication of additive effects. Accordingly, co-formulations such as IDegLira are likely to be increasingly preferred over stepwise addition and titration of the individual agents in the management of T2D.     

Antidiabetic agents and cardiovascular outcomes in patients with heart diseases

Introduction: This article reviews evidence of the benefits and risk of antidiabetic agents in cardiovascular (CV) outcomes, with a focus on medications approved by the FDA since 2008.

Study selection: Peer-reviewed articles were identified from MEDLINE and Current Content databases (both 1966 to 1 October 2016) using the search terms insulin, metformin, rosiglitazone, pioglitazone, glyburide, glipizide, glimepiride, acarbose, miglitol, albiglutide, exenatide, liraglutide, lixisenatide, dulaglutide, pramlintide, meglitinide, alogliptin, linagliptin, saxagliptin, sitagliptin, canagliflozin, dapagliflozin, empagliflozin, colesevalam, bromocriptine, mortality, myocardial infarction (MI), heart failure (HF), and stroke. Trials were included if they were randomized clinical trials evaluating adult patients (≥18 years) with type 2 diabetes; had a period of intervention and follow-up of ≥12 months; and assessed CV outcomes (CV death, fatal/non-fatal MI or HF) as endpoints. Twenty-three randomized trials were included.

Antidiabetic agents: Of agents approved prior to 2008, metformin has not been associated with measurable harm in patients with diabetes in terms of mortality and CV events (and has a trend of benefit). Controversial results existed with the use of sulfonylureas and thiazolidinediones (TZDs) for CV outcomes. Among agents approved after 2008, liraglutide and empagliflozin have been shown to be superior to placebo in improving CV outcomes.

Conclusions: The FDA regulatory mandate to demonstrate CV safety in order to approve new diabetes drugs led to an increase in the number of CV outcome trials. However, these trials have placebo-controlled, non-inferiority designs aiming to show absence of CV toxicity. More studies are needed to address other questions, including comparative effectiveness, and longer-term risk versus benefits.     

The cardiovascular effect of incretin-based therapies among type 2 diabetes: a systematic review and network meta-analysis

Objective: To evaluate the comparative cardiovascular safety of incretin-based therapies in patients with type 2 diabetes mellitus (T2DM).

Methods: Medline, Embase, the Cochrane Library and www.clinicaltrials.gov were searched for randomized controlled trials (RCTs) with duration≥12 weeks. Network meta-analysis was performed, followed by subgroup analysis and meta-regression. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence. The outcome of interest was a composite of cardiovascular death, myocardial infarction, stroke and heart failure. Odds ratio (OR) with 95% confidence interval (CI) was calculated as the measure of effect size.

Results: 281 RCTs (76.9% double-blinded) with 180,000 patients were included, comparing incretin-based therapies with other six classes of anti-diabetic drugs or placebo. A statistically significant reduction in the risk of cardiovascular events was found in favour of GLP-1RAs when compared with placebo (OR 0.89, 95%CI: 0.80–0.99) and sulfonylurea (OR 0.76, 95%CI: 0.59–0.99), whereas DPP-4 inhibitors showed a neutral effect compared with placebo (OR 0.92, 95%CI: 0.83–1.01).

Conclusions: Incretin-based therapies show similar cardiovascular risk in comparison with metformin, insulin, thiazolidinediones, alpha-glucosidase inhibitor and sodium-glucose co-transporter 2. GLP-1RA could decrease the risk compared with sulfonylurea or placebo, while DPP-4I appears to have neutral effect on cardiovascular risk.     

Potential side effects to GLP-1 agonists: understanding their safety and tolerability

Introduction: Glucagon-like peptide 1 receptor (GLP-1Rx) agonists might elicit unwelcome side effects and concerns have recently been raised about their safety.

Areas covered: Available evidence about safety, tolerability and potential adverse events relative to GLP-1Rx agonists presently used. We searched the MEDLINE database using the terms: ‘GLP-1 receptor agonists’, ‘Incretin therapy side effects’, ‘exenatide’, ‘ liraglutide’, ‘exenatide long-acting release’, ‘lixisenatide’. Articles were selected on the basis of the study design and importance, in the light of authors’ clinical experience and personal judgment. The main safety concern about GLP-1Rx agonists use is the possible association with increased risk of pancreatitis and/or tumors. This concern stems mainly from limited observations in animal models not confirmed in similar studies. Furthermore, clinical studies reporting association between GLP-1Rx agonist use and pancreatitis/cancer are marred by several biases and both clinical trials and post-marketing analyses failed to demonstrate a significant association.

Expert opinion: As stated by both FDA and EMA, the safety concerns emerged so far about GLP-1RX agonists should not affect present prescribing habits. Thus, although a strict data monitoring must be encouraged, they should not prevent access to the benefits of an innovative treatment, such as GLP-1Rx agonists use, to a large diabetic population still confronted with unmet needs.