Liraglutide improves treatment satisfaction in people with Type 2 diabetes compared with sitagliptin, each as an add on to metformin

GLP-1 Receptor Agonists for Type 2 Diabetes and Their Role in Primary Care: An Australian Perspective

The ever-increasing number of drugs available to treat type 2 diabetes and the complexity of patients with this condition present a constant challenge when it comes to identifying the most appropriate treatment approach. The more recent glucagon-like peptide-1 receptor agonists (GLP-1RAs) are non-insulin injectable options for the management of type 2 diabetes. Effective at improving glycaemic control with a low intrinsic risk of hypoglycaemia and the potential for weight reduction, this agent class is an important addition to the prescribing armamentarium. However, understanding their place in therapy may prove confusing for many primary care practitioners, especially given the common belief that 'injectables' are a last-resort treatment option, which puts them at risk of being niched alongside insulin. This review summarises the clinical evidence for GLP-1RAs and how they compare to other glucose-lowering agents in managing type 2 diabetes. It also provides practical and case-driven opinions and recommendations on the optimal use of GLP-1RAs by discussing important patient factors and clinical considerations that will help to identify those who are most likely to benefit from this class of agents.Funding: Eli Lilly Australia.

Clinical Characteristics and Satisfaction of Liraglutide Treatment among Patients with Type 2 Diabetes: A Prospective Study

Background

Evaluation of patient-reported results, treatment satisfaction, in particular, is popularly gaining recognition as crucial to the assessment of the efficiency of new therapies. The aim of this study is to examine the clinical features and treatment satisfaction with liraglutide in insulin-dependent obese patients having uncontrolled diabetes.

Methods

A prospective study was performed for 12 weeks using 64 type 2 diabetes (T2D) patients, 30 to 70 years of age, who came in for treatment to the Diabetes Treatment Center in Prince Sultan Military Medical City, Riyadh, Saudi Arabia, from November 2017 to July 2018. All the patients enrolled in this study were given liraglutide in addition to their existing treatment. For the first week, they were subcutaneously administered 0.6 mg once per day, which was gradually raised to 1.2 mg after 1 week, and the final given dose went up to 1.8 mg per day until the study period was completed. Purposive and suitable selection of the respondents was performed at their convenience. They were interviewed adopting the Diabetes Treatment Satisfaction Questionnaire (Arabic version) at baseline and after 12 weeks. Besides, the clinical variables like hemoglobin A_1c (HbA_1c), fasting blood sugar (FBS), total daily insulin dose (TDD), number of injections, and hypoglycemia/weeks were also recorded at baseline and at the end of the study.

Results

In comparison with the baseline values, notable positive differences were identified in the domains of treatment satisfaction, namely, satisfied with current treatment (P = .0001), frequency of perceived hyperglycemia (P = .0001), frequency of perceived hypoglycemia (P = .0001), convenience of current treatment (P = .0001), understanding diabetes (P = .0001), recommend the current treatment (P = .018), and continue the present treatment (P = .0001) when the study is completed. After 12 weeks, the addition of liraglutide to the existing treatment showed significant positive changes on FBS (P = .0001), HbA_1c (P = .001), TDD (P = .0001), number of injections (P = .0001), documented hypoglycemia/weeks (P = .0005), and body weight (P = .0001) in comparison with the baseline values.

Conclusions

The addition of liraglutide to the existing treatment raised the level of treatment satisfaction and minimized the frequency of hypoglycemic/hyperglycemic events apart from the other clinical variables.

Liraglutide Treatment Reduces Endothelial Endoplasmic Reticulum Stress and Insulin Resistance in Patients With Diabetes Mellitus

Background Prior studies have shown that nutrient excess induces endoplasmic reticulum ( ER ) stress in nonvascular tissues from patients with diabetes mellitus ( DM ). ER stress and the subsequent unfolded protein response may be protective, but sustained activation may drive vascular injury. Whether ER stress contributes to endothelial dysfunction in patients with DM remains unknown. Methods and Results To characterize vascular ER stress, we isolated endothelial cells from 42 patients with DM and 37 subjects without DM. Endothelial cells from patients with DM displayed higher levels of ER stress markers compared with controls without DM. Both the early adaptive response, evidenced by higher phosphorylated protein kinase-like ER eukaryotic initiation factor-2a kinase and inositol-requiring ER-to-nucleus signaling protein 1 ( P=0.02, P=0.007, respectively), and the chronic ER stress response evidenced by higher C/ EBP α-homologous protein ( P=0.02), were activated in patients with DM . Higher inositol-requiring ER-to-nucleus signaling protein 1 activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction ( r=0.53, P=0.02). Acute treatment with liraglutide, a glucagon-like peptide 1 receptor agonist, reduced p-inositol-requiring ER-to-nucleus signaling protein 1 ( P=0.01), and the activation of its downstream target c-jun N-terminal kinase ( P=0.025) in endothelial cells from patients with DM . Furthermore, liraglutide restored insulin-stimulated endothelial nitric oxide synthase activation in patients with DM ( P=0.019). Conclusions In summary, our data suggest that ER stress contributes to vascular insulin resistance and endothelial dysfunction in patients with DM . Further, we have demonstrated that liraglutide ameliorates ER stress, decreases c-jun N-terminal kinase activation and restores insulin-mediated endothelial nitric oxide synthase activation in endothelial cells from patients with DM .

Adherence to antihyperglycemic medications and glucagon-like peptide 1-receptor agonists in type 2 diabetes: clinical consequences and strategies for improvement

Adherence to antihyperglycemic medications is often suboptimal in patients with type 2 diabetes, and this can contribute to poor glycemic control, increased hospitalization, and the development of diabetic complications. Reported adherence rates to antihyperglycemics vary widely among studies, and this may be related to differences in methodology for measuring adherence, patient populations, and other factors. Poor adherence may occur regardless of the specific regimen used and whether therapy is oral or injectable, and can be especially common in chronic, asymptomatic conditions, such as type 2 diabetes. More convenient drug-administration regimens and advances in formulations and delivery devices are among strategies shown to improve adherence to antihyperglycemic therapy, especially for injectable therapy. This is exemplified by technological developments made in the drug class of glucagon-like peptide 1-receptor agonists, which are a focus of this narrative review. Dulaglutide, albiglutide, and prolonged-release exenatide have an extended duration of action and can be administered once weekly, whereas such agents as liraglutide require once-daily administration. The convenience of once-weekly versus once-daily administration is associated with better adherence in real-world studies involving this class of agent. Moreover, provision of a user-friendly delivery device has been shown to overcome initial resistance to injectable therapy among patients with type 2 diabetes. This suggests that recent innovations in drug formulation (eg, ready-to-use formulations) and delivery systems (eg, single-dose prefilled pens and hidden, ready-attached needles) may be instrumental in encouraging patient acceptance. For physicians who aim to improve their patients' adherence to antihyperglycemic medications, it is thus important to consider the patient's therapeutic experience (treatment frequency, drug formulation, delivery device). Better adherence, powered by recent technological advances in the delivery of glucagon-like peptide 1-receptor agonists, may thus lead to improved clinical outcomes in type 2 diabetes.

Evaluation of treatment satisfaction, efficacy and safety of dipeptidyl peptidase-4 inhibitors in geriatric patients with type 2 diabetes mellitus: A cross-sectionalcomparative study

Introduction

Dipeptidyl peptidase 4 (DPP4) inhibitors are attractive agents to be used in the elderly patients with Type 2 diabetes mellitus (T2DM) because of their beneficial effects.

Methods

In this cross-sectional, observational study, we evaluated and compared the treatment satisfaction using Diabetes Treatment Satisfaction Questionnaire (DTSQ) in two groups (i.e., regimens containing DPP4 inhibitors vs. other regimens). Efficacy was evaluated by assessing and comparing the glycosylated hemoglobin (HbA1c) values and the percentage of patients who achieved the glycemic control (HbA1c <7%). The adverse drug reactions (ADRs) were also recorded and compared among two groups.

Results

A total of 115 patients participated in the study (42 in Group 1 and 73 in Group 2). Significantly better DTSQ scores were observed among Group 1 patients in terms of DTSQ score total (P = 0.01) and DTSQ score for perception of hyperglycemia (P = 0.008) as compared to Group 2 patients. Significant difference was observed in HbA1c values among two groups (P = 0.02, 95% confidence interval [CI], 0.06-1.14). Also, significantly higher proportion of patients had achieved glycemic control, i.e., HbA1c <7% in Group 1 as compared to Group 2 (P = 0.002, 95% CI, 11.8%-48.1%). Significantly higher number of ADRs were observed among Group 1 patients as compared to Group 2 (P = 0.003).

Conclusion

DPP4 inhibitors seem to offer better treatment satisfaction and efficacy in geriatric T2DM patients but at the expense of increased frequency of ADRs; however, further research is warranted.

A review of glycemic efficacy of liraglutide once daily in achieving glycated hemoglobin targets compared with exenatide twice daily, or sitagliptin once daily in the treatment of type 2 diabetes

Incretin-based therapies such as glucagon-like peptide-1 (GLP-1) receptor agonists (RA) and dipeptidyl peptidase-4 (DPP-4) inhibitors have gained prominence in recent years for the treatment of type 2 diabetes (T2D). Such therapies offer the potential to stimulate endogenous insulin activity in proportion to circulating glucose levels; thereby, lowering the risk of hypoglycemic episodes. The synthetic GLP-1 RA exenatide, the human GLP-1 RA liraglutide, and the DPP-4 inhibitor sitagliptin are the first agents in their respective classes to be approved for the treatment of T2D and their efficacy and safety has been studied extensively in clinical trials. This article reviewed the efficacy of liraglutide once daily in achieving clinical guidelines-recommended glycated hemoglobin A1c levels in patients with T2D compared with exenatide twice daily, or sitagliptin once daily, based on published literature, with an aim to elucidate the preferred choice of incretin-related therapy in treating uncontrolled T2D.

Dipeptidyl peptidase-4 inhibitors as preferable oral hypoglycemic agents in terms of treatment satisfaction: Results from a multicenter, 12-week, open label, randomized controlled study in Japan (PREFERENCE 4 study)

Aims/Introduction

To compare the treatment satisfaction of four classes of oral hypoglycemic agents (OHAs): dipeptidyl peptidase‐4 (DPP‐4) inhibitors, α‐glucosidase inhibitors (αGI), biguanides (BG) and sulfonylureas (SU), which are common initial treatments for type 2 diabetes mellitus patients in Japan, and to identify the best oral hypoglycemic agent in terms of treatment satisfaction.

Materials and Methods

In this 12‐week, randomized, controlled, open‐label study, Japanese outpatients with type 2 diabetes mellitus who were naïve to pharmacological treatment were randomly assigned a DPP‐4 inhibitor, a BG., an αGI or a SU. The primary end‐point was the Oral Hypoglycemic Agent Questionnaire (OHA‐Q) total and subscale scores (treatment convenience, somatic symptoms and satisfaction) at week 4. Adherence, glycated hemoglobin (HbA1c) level and safety were also evaluated.

Results

The DPP‐4 inhibitor group scored highest in the OHA‐Q total and all subscale scores at week 4. The total score was significantly higher in the DPP‐4 inhibitor group than in the BG or αGI groups (P = 0.0084 and 0.0147, respectively). The mean total score at week 12 was also highest in the DPP‐4 inhibitor group, with a significant difference compared with the αGI group (P = 0.0293). The mean HbA1c decreased from baseline to week 12 in all groups. The DPP‐4 inhibitor group had the highest adherence at weeks 4 and 12. A total of 11 patients reported adverse events, including one hypoglycemic event in the SU group.

Conclusions

The DPP‐4 inhibitor was the most preferable option in terms of treatment satisfaction.

The efficacy and safety of liraglutide added to metformin in patients with diabetes: a meta-analysis of randomized controlled trials

Liraglutide, a glucagon-like peptide (GLP-1) receptor agonist, has showed favorable effects in the glycaemic control and weight reduction in patients with type 2 diabetes mellitus (T2DM). The meta-analysis was to compare the efficacy and safety of liraglutide added to metformin with other treatments in patients with T2DM. A systematic literature search on PubMed, Embase, Web of Science and the Cochrane library databases were performed. Eligible studies were randomized controlled trials (RCTs) of patients with T2DM who received the combination treatment of liraglutide and metformin. Pooled estimates were performed using a fixed-effects model or random-effects model. A total of nine RCTs met the inclusion criteria. Compared with control (placebo, sitagliptin, glimepiride, dulaglutide, insulin glargine, and NPH), liraglutide in combination with metformin resulted in significant reductions in HbA1c, bodyweight, FPG, and PPG, and similar reductions in SBP, and DBP. Moreover, liraglutide combined with metformin did not increase the risk of hypoglycemia, but induced a higher incidence of gastrointestinal disorders. In conclusion, this meta-analysis confirmed the use of liraglutide as add-on to metformin appeared to be effective and safe for patients with T2DM. However, considering the potential limitations in this study, more large-scale, well-conducted RCTs are needed to identify our findings.

Incretin therapies: highlighting common features and differences in the modes of action of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors

Over the last few years, incretin-based therapies have emerged as important agents in the treatment of type 2 diabetes (T2D). These agents exert their effect via the incretin system, specifically targeting the receptor for the incretin hormone glucagon-like peptide 1 (GLP-1), which is partly responsible for augmenting glucose-dependent insulin secretion in response to nutrient intake (the 'incretin effect'). In patients with T2D, pharmacological doses/concentrations of GLP-1 can compensate for the inability of diabetic β cells to respond to the main incretin hormone glucose-dependent insulinotropic polypeptide, and this is therefore a suitable parent compound for incretin-based glucose-lowering medications. Two classes of incretin-based therapies are available: GLP-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1RAs promote GLP-1 receptor (GLP-1R) signalling by providing GLP-1R stimulation through 'incretin mimetics' circulating at pharmacological concentrations, whereas DPP-4 inhibitors prevent the degradation of endogenously released GLP-1. Both agents produce reductions in plasma glucose and, as a result of their glucose-dependent mode of action, this is associated with low rates of hypoglycaemia; however, there are distinct modes of action resulting in differing efficacy and tolerability profiles. Furthermore, as their actions are not restricted to stimulating insulin secretion, these agents have also been associated with additional non-glycaemic benefits such as weight loss, improvements in β-cell function and cardiovascular risk markers. These attributes have made incretin therapies attractive treatments for the management of T2D and have presented physicians with an opportunity to tailor treatment plans. This review endeavours to outline the commonalities and differences among incretin-based therapies and to provide guidance regarding agents most suitable for treating T2D in individual patients.

Gastrointestinal hormones and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disease of women in reproductive age. It is characterized by anovulation and hyperandrogenism. Most often patients with PCOS have metabolic abnormalities such as dyslipidemia, insulin resistance, and glucose intolerance. It is not surprising that obesity is high prevalent in PCOS. Over 60 % of PCOS women are obese or overweight. Modulation of appetite and energy intake is essential to maintain energy balance and body weight. The gastrointestinal tract, where nutrients are digested and absorbed, plays a central role in energy homeostasis. The signals from the gastrointestinal tract arise from the stomach (ghrelin release), proximal small intestine (CCK release), and distal small intestine (GLP-1 and PYY) in response to food. These hormones are recognized as "appetite regulatory hormones." Weight loss is the key in the treatments of obese/overweight patients with PCOS. However, current non-pharmacologic management of body weight is hard to achieve. This review highlighted the gastrointestinal hormones, and discussed the potential strategies aimed at modifying hormones for treatment in PCOS.

Real-world clinical and economic outcomes of liraglutide versus sitagliptin in patients with type 2 diabetes mellitus in the United States

INTRODUCTION

The objective of this study was to compare the clinical effectiveness of liraglutide with sitagliptin and assess the associated economic outcomes in patients with type 2 diabetes mellitus (T2DM) treated in real-world practice in the United States (US).

METHODS

This retrospective cohort study used a large US claims database to identify patients with T2DM who initiated liraglutide or sitagliptin between January 2010 and December 2012. Adults (≥18 years old) with persistent use of therapy for ≥3 months were included. Changes in glycated hemoglobin A1c (A1C) and the proportion of patients achieving A1C targets (≤6.5% and <7%) were examined at 6-month follow-up. Diabetes-related total, medical, and pharmacy costs over the follow-up period were assessed. Multivariable regression models were used to estimate the outcomes associated with liraglutide relative to sitagliptin, adjusting for differences in patient demographics and clinical characteristics.

RESULTS

The study included 1,465 patients with T2DM who initiated liraglutide (N = 376) or sitagliptin (N = 1,089) (mean age [standard deviation (SD)]: 54 [8.9] vs. 58 [10.8] years; 43.9% vs. 61.8% males; both P < 0.01). After controlling for confounding factors, liraglutide patients experienced 0.31% points greater reduction in A1C (0.95% vs. 0.63% points; P < 0.01) at 6-month follow-up than sitagliptin patients and were more likely to reach A1C targets of ≤6.5% (odds ratio [OR]: 2.00; P < 0.01) and <7% (OR: 1.55; P < 0.01). Liraglutide patients had $994 lower mean diabetes-related medical costs ($1,241 vs. $2,235; P < 0.01), but $544 higher diabetes-related pharmacy costs ($2,100 vs. $1,556; P < 0.01) during the follow-up. No difference was found in the total mean diabetes-related costs between the two cohorts.

CONCLUSION

Liraglutide showed greater improvement in glycemic outcomes than sitagliptin among adult patients with T2DM in real-world clinical practice. Although diabetes-related pharmacy costs for patients using liraglutide were higher compared with sitagliptin, these were offset by significantly lower diabetes-related medical costs, resulting in similar total diabetes-related costs between the two treatment groups.

Liraglutide Versus Sitagliptin in a 24-week, Multicenter, Open-label, Randomized, Parallel-group Study in Japanese Type 2 Diabetes Mellitus Patients Responding Inadequately to a Sulfonylurea and/or One or Two Other Oral Antidiabetic Drugs (JDDM 33)

OBJECTIVE

Liraglutide (glucagon-like peptide-1 [GLP-1] receptor agonist) and sitagliptin (dipeptidyl peptidase-4 inhibitor) are approved in Japan for treating type 2 diabetes mellitus (T2DM). We compared the efficacy and safety of adding liraglutide or sitagliptin to a sulfonylurea in Japanese T2DM patients.

METHODS

Patients aged 18 to <80 years with hemoglobin A1c (HbA1c; National Glycohemoglobin Standardization Program [NGSP]) of 6.9–9.4%, body mass index ≤35 kg/m², and treatment with a sulfonylurea and/or one or two non-sulfonylurea oral antidiabetic drugs for greater than or equal to eight weeks before enrollment were eligible. Patients were randomized in an open-label manner to either 0.9 mg/day liraglutide (n = 50) or 50–100 mg/day sitagliptin (n = 49) and were treated for 24 weeks. Non-sulfonylureas were discontinued before randomization. Patients using other oral antidiabetic drugs started sulfonylurea treatment. The primary endpoint was the change in HbA1c from baseline to Week 24.

RESULTS

HbA1c decreased in both groups, and the reduction was significantly greater throughout in the liraglutide group except for Week 24 (0.59 ± 0.80 vs. 0.24 ± 0.94%; P = 0.0525). Fasting plasma glucose (FPG) decreased significantly in the liraglutide group compared with the sitagliptin group (−21.15 ± 31.22 vs. +0.46 ± 39.39 mg/dL; P = 0.0014). Homeostasis model assessment of β cell function and C-peptide increased significantly in the liraglutide group but not in the sitagliptin group. Hypoglycemic symptoms and adverse events occurred in four and nine patients, respectively, in the liraglutide group, and in two and five patients, respectively, in the sitagliptin group.

CONCLUSION

Treatment with liraglutide or sitagliptin together with a sulfonylurea improved HbA1c in Japanese T2DM patients in primary care. Both drugs were associated with low rates of adverse events and hypoglycemia. The improvement in β cell function probably contributed to the improvement in glycemic control in the liraglutide group.

GLP-1 receptor agonists vs. DPP-4 inhibitors for type 2 diabetes: is one approach more successful or preferable than the other?

BACKGROUND

In patients with type 2 diabetes (T2D), incretin-based therapies improve glycaemic control with low incidence of hypoglycaemia and without weight gain, both advantages over traditional add-ons to metformin. Dipeptidyl peptidase-4 (DPP-4) inhibitors are administered orally and provide a physiological increase in glucagon-like peptide-1 (GLP-1) levels, while GLP-1 receptor agonists (GLP-1RAs) are injectable and deliver pharmacological levels of GLP-1RA. This review aims to distinguish between GLP-1RAs and DPP-4 inhibitors, and discuss when each may be favoured in clinical practice.

METHODS

A MEDLINE search, limited to human clinical trials and using the search criteria 'GLP-1RA' or 'DPP-4 inhibitor', identified seven head-to-head studies and one relevant post hoc analysis (all a GLP-1RA vs. the DPP-4 inhibitor sitagliptin). In combination with treatment algorithms, product prescribing information and personal clinical experience, these studies were used to compare the efficacy and suitability of GLP-1RAs and DPP-4 inhibitors in patients with T2D.

RESULTS

In head-to-head clinical trials, GLP-1RAs provided greater glycaemic control, weight loss and overall treatment satisfaction vs. the DPP-4 inhibitor sitagliptin. Transient nausea was more frequent with GLP-1RAs and should be addressed through patient education and an incremental dosing approach. Current treatment algorithms recommend incretin-based therapy use after metformin failure, but local guidance may restrict their use.

CONCLUSION

GLP-1RAs provide superior glycaemic control and weight loss vs. DPP-4 inhibitors in patients with T2D. DPP-4 inhibitors may sometimes be preferred to a GLP-1RA if weight is not a concern, oral administration is a desirable feature or when a GLP-1RA cannot be tolerated.

Incorporating incretin-based therapies into clinical practice for patients with type 2 diabetes

Background

Effective, evidence-based management of type 2 diabetes (T2D) requires the integration of the best available evidence with clinical experience and patient preferences.

Methods

Studies published from 2000 to 2012 evaluating glucagon-like peptide-1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) were identified using PubMed. The author contextualized the study findings with his clinical experience.

Results

Incretin-based therapy targets multiple dysfunctional organs in T2D. Injectable GLP-1RAs provide substantial glycemic control and weight reduction; while oral DPP-4 inhibitors provide moderate glycemic control and weight neutrality. Both classes are effective, well tolerated, and associated with a low incidence of hypoglycemia when used alone or in combination with other antidiabetes agents. GLP-1RAs are associated with transient nausea and, like DPP-4 inhibitors, rare pancreatitis.

Conclusion

Data indicate and clinical experience confirms that incretins are well tolerated in appropriate patients and provide sustained glycemic control and weight loss or weight neutrality throughout T2D progression.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-014-0100-5) contains supplementary material, which is available to authorized users.

Comparative effectiveness of liraglutide in the treatment of type 2 diabetes

Type 2 diabetes is characterized by a progressive decline in beta cell function, with consequent worsening of glycemic control. The ideal antihyperglycemic treatment should achieve good and sustained glycemic control, with a low risk of hypoglycemia and no weight gain. This paper reviews the efficacy and tolerability of liraglutide, a glucagon-like peptide-1 receptor agonist approved for the treatment of type 2 diabetes. Once-daily injection of liraglutide (at doses of 1.2 mg and 1.8 mg), as monotherapy or in combination with one or two oral antihyperglycemic agents, was associated with greater improvements in glycemic control compared with active comparators or placebo in several controlled, randomized Phase III trials, including the six trials of the LEAD (Liraglutide Effect and Action in Diabetes) program. Liraglutide also improved beta cell function, body weight, systolic blood pressure, and lipid profile, thereby achieving many of the goals of ideal antihyperglycemic therapy. Liraglutide was generally well tolerated in the Phase III trials. The most common adverse events were nausea, vomiting, and diarrhea, usually of mild to moderate intensity. The observed rate of pancreatitis was low and comparable with that of the general diabetic population. In conclusion, although most trials were relatively short and focused on surrogate endpoints, liraglutide emerges as an effective and well tolerated treatment for type 2 diabetes, carrying a low risk of hypoglycemia, weight loss, and possible reduction of cardiovascular risk.

Efficacy and safety over 26 weeks of an oral treatment strategy including sitagliptin compared with an injectable treatment strategy with liraglutide in patients with type 2 diabetes mellitus inadequately controlled on metformin: a randomised clinical trial

AIMS/HYPOTHESIS

The aim of this work was to compare treatment intensification strategies based on orally administered vs injectable incretin-based antihyperglycaemic agents in patients with type 2 diabetes mellitus on metformin monotherapy.

METHODS

In a 26 week, open-label study, 653 patients (baseline HbA1c = 8.2% [66 mmol/mol]) were randomised at 111 sites in 21 countries in a 1:1 ratio to a strategy using oral agents (starting with sitagliptin 100 mg/day) or a strategy using the injectable drug liraglutide starting at a dose of 0.6 mg/day, up-titrated to 1.2 mg/day after 1 week. The following patients with type 2 diabetes mellitus were recruited for the study: those aged 18-79 years, on a stable dose of metformin monotherapy ≥1,500 mg/day for ≥12 weeks, with an HbA1c ≥7.0% (53 mmol/mol) and ≤11.0% (97 mmol/mol) and a fasting fingerstick glucose (FFG) <15 mmol/l (<270 mg/dl) at the randomisation visit, deemed capable by the investigator of using a Victoza pen injection device (containing 6 mg/ml liraglutide; Novo Nordisk, Bagsværd, Denmark). Women taking part in the study agreed to remain abstinent or use an acceptable method of birth control during the study. Randomisation was performed via a computer-generated allocation schedule using an interactive voice response system. After 12 weeks, patients on sitagliptin with HbA1c  ≥ 7.0% (53 mmol/mol) and fasting glucose >6.1 mmol/l had their treatment intensified with glimepiride; patients on liraglutide with HbA1c  ≥ 7.0% (53 mmol/mol) had the dose up-titrated to 1.8 mg/day. The primary analysis assessed whether the strategy using oral drugs was non-inferior to that using an injectable drug regarding HbA1c change from baseline at week 26 using a per-protocol (PP) population and a non-inferiority margin of 0.4%.

RESULTS

In the PP population (522 patients included: oral strategy, n = 269; injectable strategy, n = 253) antihyperglycaemic therapy was intensified at week 12 in 50.2% and 28.5%, respectively. HbA1c decreased over 26 weeks in both treatment strategy groups, with a larger initial reduction at week 12 in the injectable strategy group. The LS mean change in HbA1c at week 26 was -1.3% (95% CI -1.4, -1.2) in the oral strategy group and -1.4% (95% CI -1.5, -1.3) in the injectable strategy group; the study met the non-inferiority criterion. Both treatment regimens were generally well tolerated; hypoglycaemia was reported more often with the oral strategy, while nausea, vomiting, diarrhoea and abdominal pain were reported more often with the injectable strategy.

CONCLUSIONS/INTERPRETATION

An oral, incretin-based treatment strategy with sitagliptin and, if needed, glimepiride may be a good approach in many patients with type 2 diabetes mellitus for managing inadequate glycaemic control on metformin monotherapy, as compared with an injectable treatment strategy with liraglutide. The oral and injectable strategies had similar effects on HbA1c and had good overall tolerability. Trial registration ClinicalTrials.gov NCT01296412 Funding The study was sponsored by Merck Sharp & Dohme Corp., a subsidiary of Merck and Co., Inc., Whitehouse Station, NJ, USA.

A retrospective, case-note survey of type 2 diabetes patients prescribed incretin-based therapies in clinical practice

INTRODUCTION

While incretin-based therapies have been compared in clinical trials, data comparing their relative efficacy in clinical practice remain limited, particularly when prescribed according to clinical guidelines. This study assessed the clinical and cost-effectiveness of, and patient preference for, incretin-based therapies initiated according to the National Institute for Health and Clinical Excellence (NICE) recommendations in UK clinical practice.

METHODS

In a retrospective chart audit, anonymized data were collected for patients receiving incretin-based therapy according to NICE recommendations in clinical practice in Wales, UK. Parameters assessed included glycated hemoglobin (HbA1c), weight, achievement of NICE treatment continuation criteria, adverse events, treatment discontinuation, and drug cost-effectiveness based on observed treatment effects. Treatment preference for a dipeptidyl peptidase-4 inhibitor (DPP-4i) or glucagon-like peptide-1 receptor agonist (GLP-1RA) was assessed prospectively.

RESULTS

Patients (1,114) were followed-up for a median of 48 weeks (256 received liraglutide, 148 received exenatide twice daily, and 710 received a DPP-4i). Liraglutide reduced HbA1c significantly more versus exenatide or DPP-4i (both P < 0.05). Weight changes were similar for GLP-1RAs but significantly greater vs. DPP-4is (both P < 0.05). NICE treatment continuation criteria were met by 32% and 24% of liraglutide 1.2 mg- and exenatide-treated patients (≥1% HbA1c reduction, ≥3% weight loss), and 61% of DPP-4i-treated patients (≥0.5% HbA1c reduction). Life-years gained per patient were 0.12, 0.08, and 0.07, and costs per quality-adjusted life-year were £16,505, £16,648, and £20,661 for liraglutide, exenatide, and DPP-4is, respectively. More patients (62.5%) preferred the GLP-1RA profile, with these patients having higher baseline body mass index score and HbA1c values, and longer diabetes duration than those preferring the DPP-4i profile.

CONCLUSION

When prescribed according to NICE recommendations, incretin-based therapies are both clinically and cost-effective options, with liraglutide providing greatest HbA1c reductions. Greater body weight reductions occur with GLP-1RAs compared with DPP-4is. Patients with higher baseline HbA1c and longer diabetes duration prefer a GLP-1RA profile versus a DPP-4i.

Effects of exenatide and liraglutide on heart rate, blood pressure and body weight: systematic review and meta-analysis

OBJECTIVES

To synthesise current evidence for the effects of exenatide and liraglutide on heart rate, blood pressure and body weight.

DESIGN

Meta-analysis of available data from randomised controlled trials comparing Glucagon-like peptide-1 (GLP-1) analogues with placebo, active antidiabetic drug therapy or lifestyle intervention.

PARTICIPANTS

Patients with type 2 diabetes.

OUTCOME MEASURES

Weighted mean differences between trial arms for changes in heart rate, blood pressure and body weight, after a minimum of 12-week follow-up.

RESULTS

32 trials were included. Overall, GLP-1 agonists increased the heart rate by 1.86 beats/min (bpm) (95% CI 0.85 to 2.87) versus placebo and 1.90 bpm (1.30 to 2.50) versus active control. This effect was more evident for liraglutide and exenatide long-acting release than for exenatide twice daily. GLP-1 agonists decreased systolic blood pressure by -1.79 mm Hg (-2.94 to -0.64) and -2.39 mm Hg (-3.35 to -1.42) compared to placebo and active control, respectively. Reduction in diastolic blood pressure failed to reach statistical significance (-0.54 mm Hg (-1.15 to 0.07) vs placebo and -0.50 mm Hg (-1.24 to 0.24) vs active control). Body weight decreased by -3.31 kg (-4.05 to -2.57) compared to active control, but by only -1.22 kg (-1.51 to -0.93) compared to placebo.

CONCLUSIONS

GLP-1 analogues are associated with a small increase in heart rate and modest reductions in body weight and blood pressure. Mechanisms underlying the rise in heart rate require further investigation.

Incretin-based therapies for type 2 diabetes mellitus: a review of direct comparisons of efficacy, safety and patient satisfaction

BACKGROUND

Clinical trials comparing incretin-based therapies-glucagon-like peptide-1 receptor agonists (exenatide-twice daily and once weekly-and once-daily liraglutide) and dipeptidyl peptidase-4 inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin)-with placebo and oral antidiabetic drugs show that these therapies effectively control glycaemia, with low risk of hypoglycaemia. Glucagon-like peptide-1 receptor agonists are associated with weight loss and reductions in systolic blood pressure, while dipeptidyl peptidase-4 inhibitors are weight-neutral. Based on this, the National Institute for Health and Clinical Excellence recommends using these agents in patients with type 2 diabetes for whom excess weight and/or hypoglycaemia are problematic.

AIM OF THE REVIEW

This review aims to help decision making when selecting and using incretin-based therapies in type 2 diabetes.

METHODS

A search or MEDLINE and Cochrane clinical trials databases, limited to clinical trials in humans, was performed using the search criteria 'exenatide or liraglutide or vildagliptin or sitagliptin, or saxagliptin or linagliptin'. Abstracts presented at recent American Diabetes Association and European Association for the Study of Diabetes meetings were also searched. Eighteen clinical trials directly comparing incretin-based therapies were identified.

RESULTS

Glucagon-like peptide-1 receptor agonists achieved significantly greater reductions in glycated hemoglobin and weight than dipeptidyl peptidase-4 inhibitors, which have a neutral effect on weight. Between-treatment differences were clinically important. Gastrointestinal side effects were more frequent with glucagon-like peptide-1 receptor agonists versus dipeptidyl peptidase-4 inhibitors. Comparisons between glucagon-like peptide-1 receptor agonists and between dipeptidyl peptidase-4 inhibitors showed that differences within the available agents in the two sub-classes are small. Greater treatment satisfaction was reported with glucagon-like peptide-1 receptor agonists versus dipeptidyl peptidase-4 inhibitors.

CONCLUSION

Glucagon-like peptide-1 receptor agonists achieve greater glycated hemoglobin reductions than dipeptidyl peptidase-4 inhibitors, with concomitant weight loss. Probably due to the greater efficacy of glucagon-like peptide-1 receptor agonists, patient satisfaction is greater with these agents compared with dipeptidyl peptidase-4 inhibitors despite injectable versus oral administration and more frequent gastrointestinal side effects with the agonists.

Comparison of efficacy between incretin-based therapies for type 2 diabetes mellitus

Type 2 diabetes mellitus is widely prevalent and is often coexistent with obesity. Many of the available treatment options have side effects such as weight gain which often affect patient's willingness to continue the treatment. Effective weight loss, lack of significant hypoglycaemia, and favourable cardiometabolic profile make Incretin based therapies an attractive treatment option for type 2 diabetes. Incretin based therapies are available as either incretin mimetics (also called GLP-1 agonists) or incretin enhancers (DPP-4 inhibitors). Although agents in both these classes of incretin based therapy are effective through a common GLP-1 pathway, there are many differences amongst them including the route of administration, frequency of administration, effects on body weight, extent of glycaemic improvement. There are several trials evaluating these individual incretin based agents either as monotherapy or in combination with other anti-diabetic agents, however very few have looked into direct comparison amongst the agents in these two classes. This review is aimed to look at important mechanistic differences between incretin mimetics and enhancers through direct comparison trials and impact of these differences on biochemical, metabolic and patient satisfaction parameters.

Efficacy and safety of switching from the DPP-4 inhibitor sitagliptin to the human GLP-1 analog liraglutide after 52 weeks in metformin-treated patients with type 2 diabetes: a randomized, open-label trial

OBJECTIVE

To assess the efficacy and safety of switching from sitagliptin to liraglutide in metformin-treated adults with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In an open-label trial, participants randomized to receive either liraglutide (1.2 or 1.8 mg/day) or sitagliptin (100 mg/day), each added to metformin, continued treatment for 52 weeks. In a 26-week extension, sitagliptin-treated participants were randomly allocated to receive instead liraglutide at either 1.2 or 1.8 mg/day, while participants originally randomized to receive liraglutide continued unchanged.

RESULTS

Although 52 weeks of sitagliptin changed glycosylated hemoglobin (HbA(1c)) by -0.9% from baseline, additional decreases occurred after switching to liraglutide (1.2 mg/day, -0.2%, P = 0.006; 1.8 mg/day, -0.5%, P = 0.0001). Conversion to liraglutide was associated with reductions in fasting plasma glucose (FPG) (1.2 mg/day, -0.8 mmol/L, P = 0.0004; 1.8 mg/day, -1.4 mmol/L, P < 0.0001) and body weight (1.2 mg/day, -1.6 kg; 1.8 mg/day, -2.5 kg; both P < 0.0001) and with an increased proportion of patients reaching HbA(1c) <7% (from ∼30% to ∼50%). Overall treatment satisfaction, assessed by the Diabetes Treatment Satisfaction Questionnaire, improved after switching to liraglutide (pooled 1.2 and 1.8 mg/day, 1.3; P = 0.0189). After switching, mostly transient nausea occurred in 21% of participants, and minor hypoglycemia remained low (3-4% of participants). Continuing liraglutide treatment at 1.2 mg/day and 1.8 mg/day for 78 weeks reduced HbA(1c) (baseline 8.3 and 8.4%, respectively) by -0.9 and -1.3%, respectively; FPG by -1.3 and -1.7 mmol/L, respectively; and weight by -2.6 and -3.1 kg, respectively, with 9-10% of participants reporting minor hypoglycemia.

CONCLUSIONS

Glycemic control, weight, and treatment satisfaction improved after switching from sitagliptin to liraglutide, albeit with a transient increase in gastrointestinal reactions.

Liraglutide: a review of its use in the management of type 2 diabetes mellitus

Liraglutide (Victoza®) is a subcutaneously administered glucagon-like peptide-1 (GLP-1) receptor agonist produced by recombinant DNA technology and used as an adjunct to diet and exercise in the treatment of adults with type 2 diabetes mellitus. This article reviews the clinical efficacy and tolerability of liraglutide in adults with type 2 diabetes, and provides a summary of its pharmacological properties. Recently published pharmacoeconomic studies of liraglutide are also reviewed. Administered subcutaneously, liraglutide (usually 1.2 or 1.8 mg once daily) generally produced greater improvements in glycaemic control than active comparators or placebo when administered as monotherapy or in combination with one or two oral antidiabetic drugs (OADs) to adults with type 2 diabetes in numerous randomized, controlled phase III trials. These included six trials in the LEAD trial programme that was designed to evaluate the efficacy and safety of liraglutide across a continuum of antihyperglycaemic management for patients with type 2 diabetes. Liraglutide was generally well tolerated, with a low risk of hypoglycaemia evident, in the phase III trials. The most common adverse events were gastrointestinal and included nausea and diarrhoea; most events were mild to moderate in severity and decreased in incidence over time. In conclusion, liraglutide has an important place in the management of adults with type 2 diabetes across a continuum of care. As well as providing effective glycaemic control, liraglutide improves pancreatic β-cell function and leads to bodyweight loss, thereby addressing some of the unmet needs of patients treated with traditional OADs.

Effects of glucagon-like peptide-1 receptor agonists on weight loss: systematic review and meta-analyses of randomised controlled trials

OBJECTIVE

To determine whether treatment with agonists of glucagon-like peptide-1 receptor (GLP-1R) result in weight loss in overweight or obese patients with or without type 2 diabetes mellitus.

DESIGN

Systematic review with meta-analyses.

DATA SOURCES

Electronic searches (Cochrane Library, Medline, Embase, and Web of Science) and manual searches (up to May 2011). Review methods Randomised controlled trials of adult participants with a body mass index of 25 or higher; with or without type 2 diabetes mellitus; and who received exenatide twice daily, exenatide once weekly, or liraglutide once daily at clinically relevant doses for at least 20 weeks. Control interventions assessed were placebo, oral antidiabetic drugs, or insulin.

DATA EXTRACTION

Three authors independently extracted data. We used random effects models for the primary meta-analyses. We also did subgroup, sensitivity, regression, and sequential analyses to evaluate sources of intertrial heterogeneity, bias, and the robustness of results after adjusting for multiple testing and random errors.

RESULTS

25 trials were included in the analysis. GLP-1R agonist groups achieved a greater weight loss than control groups (weighted mean difference -2.9 kg, 95% confidence interval -3.6 to -2.2; 21 trials, 6411 participants). We found evidence of intertrial heterogeneity, but no evidence of bias or small study effects in regression analyses. The results were confirmed in sequential analyses. We recorded weight loss in the GLP-1R agonist groups for patients without diabetes (-3.2 kg, -4.3 to -2.1; three trials) as well as patients with diabetes (-2.8 kg, -3.4 to -2.3; 18 trials). In the overall analysis, GLP-1R agonists had beneficial effects on systolic and diastolic blood pressure, plasma concentrations of cholesterol, and glycaemic control, but did not have a significant effect on plasma concentrations of liver enzymes. GLP-1R agonists were associated with nausea, diarrhoea, and vomiting, but not with hypoglycaemia.

CONCLUSIONS

The present review provides evidence that treatment with GLP-1R agonists leads to weight loss in overweight or obese patients with or without type 2 diabetes mellitus.

Incretin therapy--present and future

Although newer treatments for type 2 diabetes (T2D) patients have produced continual improvements in outcome, a large and growing population with prediabetes remains under-treated. In the last few years, incretin-based therapies have become an important treatment option for patients with T2D. There are two classes of incretin agents: the dipeptidyl peptidase-4 (DPP-4) inhibitors and the glucagon like peptide 1 (GLP-1) receptor agonists. The ultimate goal of agents within both of these classes is to increase GLP-1 signaling, which results in augmented glucose-induced insulin secretion, inhibition of glucagon secretion, and decreased appetite. This should result in improved regulation of glucose homeostasis. GLP-1 receptor agonists enable patients to achieve significant weight loss. In contrast, DPP-4 inhibitors result in a less dramatic increase in GLP-1 levels; therefore, they are weight neutral. Incretin therapies are currently recommended for use early in the treatment algorithm for T2D patients whose disease is not manageable by diet and exercise alone, but the potential for these agents may be farther reaching. Current studies are evaluating the potential benefits of combining incretin therapies with basal insulin to provide continuous glucose control before and after meals. In addition, these agents may be promising for patients with prediabetes since they effectively reduce glycosylated hemoglobin levels and fasting plasma glucose levels, enable weight control, and have the potential to preserve β-cell function. Clearly, all of these properties are desirable for patients with prediabetes.