GLP-1 Receptor Agonists: Practical Considerations for Clinical Practice

Impact of polyethylene glycol loxenatide on cardiovascular outcomes in patients with type 2 diabetes: study protocol for a multicentre, randomised, double-blind, placebo-controlled trial (BALANCE-3)

INTRODUCTION

Recent cardiovascular outcomes trials have demonstrated that glucagon-like peptide 1 receptor agonist (GLP-1RA) decreases the incidence of major adverse cardiovascular events (MACEs) in individuals with type 2 diabetes mellitus (T2DM). Polyethylene glycol loxenatide (PEG-Loxe) is a once-weekly GLP-1RA obtained by modifying exendin-4. No clinical trials have been designed to assess the impact of PEG-Loxe on cardiovascular (CV) outcomes in individuals with T2DM. This trial aims to test the hypothesis that compared with placebo, PEG-Loxe treatment does not result in an unacceptable increase in CV risk in individuals with T2DM.

METHODS AND ANALYSIS

This study is a multicentre, randomised, double-blind, placebo-controlled trial. Patients with T2DM who fulfilled the inclusion criteria were randomly divided to receive weekly administration of either PEG-Loxe 0.2 mg or placebo (1:1 ratio). The randomisation was stratified according to utilisation of sodium-glucose cotransporter 2 inhibitors, history of CV disease and body mass index. The research period is expected to be 3 years, with a 1-year recruitment period and a 2-year follow-up period. The primary outcome is the occurrence of the first MACE, described as CV death, non-fatal myocardial infarction or non-fatal stroke. The statistical analyses were undertaken on the intent-to-treat patient. The primary outcome was evaluated using a Cox proportional hazards model with treatment and randomisation strata as the covariates.

ETHICS AND DISSEMINATION

The current research has been authorised by the Ethics Committee of Tianjin Medical University Chu Hsien-I Memorial Hospital (approval number: ZXYJNYYhMEC2022-2). Researchers must acquire informed consent from every participant before conducting any protocol-associated procedures. The findings of this study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2200056410.

Efficacy of polyethylene glycol loxenatide versus insulin glargine on glycemic control in patients with type 2 diabetes: a randomized, open-label, parallel-group trial

Objective: This trial aimed to evaluate the glycemic control of polyethylene glycol loxenatide measured with continuous glucose monitoring (CGM) in patients with type 2 diabetes mellitus (T2DM), with the hypothesis that participants given PEG-Loxe would spend more time in time-in-range (TIR) than participants were given insulin glargine after 24 weeks of treatment. Methods: This 24-week, randomized, open-label, parallel-group study was conducted in the Department of Endocrine and Metabolic Diseases, Longhu Hospital, Shantou, China. Participants with T2DM, who were ≥45 years of age, HbA1c of 7.0%-11.0%, and treated at least 3 months with metformin were randomized (1:1) to receive PEG-Loxe or insulin glargine. The primary endpoint was TIR (blood glucose range: 3.9-10.0 mmol/L) during the last 2 weeks of treatment (weeks 22-24). Results: From March 2020 to April 2022, a total of 107 participants with T2DM were screened, of whom 78 were enrolled into the trial (n = 39 per group). At the end of treatment (weeks 22-24), participants given PEG-Loxe had a greater proportion of time in TIR compared with participants given insulin glargine [estimated treatment difference (ETD) of 13.4% (95% CI, 6.8 to 20.0, p < 0.001)]. The tight TIR (3.9-7.8 mmol/L) was greater with PEG-Loxe versus insulin glargine, with an ETD of 15.6% (95% CI, 8.9 to 22.4, p < 0.001). The time above range (TAR) was significantly lower with PEG-Loxe versus insulin glargine [ETD for level 1: -10.5% (95% CI: -14.9 to -6.0), p < 0.001; ETD for level 2: -4.7% (95% CI: -7.9 to -1.5), p = 0.004]. The time below range (TBR) was similar between the two groups. The mean glucose was lower with PEG-Loxe versus insulin glargine, with an ETD of -1.2 mmol/L (95% CI, -1.9 to -0.5, p = 0.001). The SD of CGM glucose levels was 1.88 mmol/L for PEG-Loxe and 2.22 mmol/L for insulin glargine [ETD -0.34 mmol/L (95% CI: -0.55 to -0.12), p = 0.002], with a similar CV between the two groups. Conclusion: The addition of once-weekly GLP-1RA PEG-Loxe to metformin was superior to insulin glargine in improving glycemic control and glycemic variability evaluated by CGM in middle-aged and elderly patients with T2DM.

The potential role of incretin-based therapies for polycystic ovary syndrome: a narrative review of the current evidence

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects women of reproductive age. Metabolic consequences associated with PCOS include, but are not limited to, insulin resistance (IR), type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). This narrative review aims to provide a comprehensive overview of the potential therapeutic roles of the incretin-based therapies in the management of PCOS.

METHODS

We performed a systematic search of databases including PubMed, MEDLINE and EMBASE up to 1 October 2020. We developed a search string of medical subject headings (MeSH) including the terms PCOS, incretin mimetics, glucagon-like peptide-1 (GLP-1), glucagon-like peptide-1 receptor antagonists (GLP-1 RAs), liraglutide, exenatide, semaglutide, dipeptidyl peptidase-4 (DPP-4) inhibitors, combined with IR, testosterone and sex hormone-binding globulin (SHBG).

RESULTS

We identified 854 relevant articles and, after the initial screening, eight interventional animal studies, one observational animal study, 14 interventional human studies, two case-control studies and one systematic review were included. These studies showed the potential significant roles of GLP-1 RAs and DPP-4 inhibitors in the management of PCOS, with significant improvements in the metabolic parameters, including substantial weight reduction and improved insulin sensitivity. These agents also improved the hormonal parameters through decreased free androgen and increased SHBG. Moreover, they improved menstrual regularity, increased fertility with enhanced ovulation and pregnancy in obese women with PCOS.

CONCLUSION

GLP-1 RAs and DPP-4 inhibitors have a promising therapeutic role in PCOS; however, larger clinical trials are needed to establish the role of incretin-based therapies in the management of PCOS.

Optimizing Therapeutic Outcomes With Oral Semaglutide: A Patient-Centered Approach

In September 2019, the U.S. Food and Drug Administration approved oral semaglutide as the first orally administered glucagon-like peptide 1 (GLP-1) receptor agonist for treating people with type 2 diabetes. Although injectable GLP-1 receptor agonists are well-established treatment options for people with type 2 diabetes, clinical experience with an oral formulation in this class is limited. This article provides practical guidance for diabetes care and education specialists on how to effectively counsel patients initiating therapy with oral semaglutide on appropriate administration of the treatment and its possible effects on glycemic control, body weight, and quality of life. Strategies for mitigating potential side effects typical of the GLP-1 receptor agonist class, namely nausea, vomiting, and diarrhea, are also provided. Involving patients in treatment decisions and educating them about available and prescribed medications are key strategies for encouraging treatment adherence and ensuring optimal therapeutic outcomes.

Pharmacokinetic and dose-finding studies on efpeglenatide in patients with type 2 diabetes

AIM

To assess the efficacy, safety and pharmacokinetic/pharmacodynamic properties of efpeglenatide, a long-acting glucagon-like peptide-1 receptor agonist, in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Two randomized, double-blind, placebo-controlled phase 2 trials were conducted. The single-dose study (n = 48) was a first-in-patient, sequential dose-escalation study. Patients received a single subcutaneous injection of efpeglenatide (2-100 μg/kg) or placebo. The repeated-dose study (n = 71) was a multiple-ascending-dose trial. Patients received weekly (1, 2 or 4 mg once weekly; 8-week period) or monthly (8, 12 or 16 mg once monthly; 9-week period) subcutaneous injections of efpeglenatide or placebo (without titration).

RESULTS

Both studies demonstrated dose-proportional increases in efpeglenatide serum concentrations. The median time to attain maximum serum concentration (t_max ) for efpeglenatide ranged from 72 to 144 hours in the single-dose study and from 48 to 120 hours in the repeated-dose study (following final dose). Geometric mean t_1/2 ranged from 135 to 180 hours across studies. Peak-to-trough ratios in the repeated-dose study ranged from 1.3 to 1.4 with once-weekly dosing and from 5.9 to 12.9 with once-monthly dosing. Following a single dose of efpeglenatide 14-100 μg/kg, fasting plasma glucose and postprandial plasma glucose levels were decreased at week 1 and remained below baseline levels for ≥3 weeks post-dosing. Repeated doses of efpeglenatide led to significant reductions in glycated haemoglobin vs placebo. In both studies, efpeglenatide was generally well tolerated. Gastrointestinal disorders were the most frequently reported treatment-emergent adverse events in efpeglenatide-treated patients.

CONCLUSIONS

The delayed t_max, long half-life, and low peak-to-trough ratios observed demonstrate potential for improved efficacy and dosing flexibility, with good tolerability of efpeglenatide in patients with T2D.

Clinical pharmacology of glucagon-like peptide-1 receptor agonists

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are an important asset in the armamentarium for the treatment of type 2 diabetes mellitus (type 2 DM). Incretin failure is a critical etiopathogenetic feature of type 2 DM, which, if reversed, results in improved glycaemic control. GLP-1 RAs are injectable peptides that resemble the structure and function of endogenous incretin GLP-1, but as they are not deactivated by the dipeptidyl peptidase-4 (DPP-4), their half-life is prolonged compared with native GLP-1. Based on their ability to activate GLP-1 receptor, GLP-1 RAs are classified as short-acting (exenatide twice-daily and lixisenatide once-daily), and long-acting (liraglutide once-daily and the once-weekly formulations of exenatide extended-release, dulaglutide, and albiglutide). Semaglutide, another long-acting, once-weekly GLP-1 RA, was recently approved by the FDA and EMA. Although all of these agents potently reduce haemoglobin A1C (HbA1c), there are unique features and fundamental differences among them related to fasting and postprandial hyperglycaemia reduction, weight loss potency, cardiovascular protection efficacy, and adverse events profile. It is imperative that current evidence be integrated and applied in the context of an individualised patient-centred approach. This should include not only glucose management but also targeting as many as possible of the pathophysiologic mechanisms responsible for type 2 DM development and progression.

Autophagy and its link to type II diabetes mellitus

Autophagy, a double-edged sword for cell survival, is the research object on 2016 Nobel Prize in Physiology or Medicine. Autophagy is a molecular mechanism for maintaining cellular physiology and promoting survival. Defects in autophagy lead to the etiology of many diseases, including diabetes mellitus (DM), cancer, neurodegeneration, infection disease and aging. DM is a metabolic and chronic disorder and has a higher prevalence in the world as well as in Taiwan. The character of diabetes mellitus is hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and failure of producing insulin on pancreatic beta cells. In T2DM, autophagy is not only providing nutrients to maintain cellular energy during fasting, but also removes damaged organelles, lipids and miss-folded proteins. In addition, autophagy plays an important role in pancreatic beta cell dysfunction and insulin resistance. In this review, we summarize the roles of autophagy in T2DM.

Glucagon-like Peptide-1 Receptor Agonist Treatment Attributes Important to Injection-Naïve Patients with Type 2 Diabetes Mellitus: A Multinational Preference Study

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) differ in efficacy, side effects, dosing frequency, and device-related attributes. This study assessed the relative importance of treatment-related attributes in influencing preferences for GLP-1RAs among injection-naïve patients with type 2 diabetes mellitus (T2DM).

METHODS

Injection-naïve T2DM patients from five countries completed a Web-based discrete choice experiment (DCE) survey. Patients chose between hypothetical treatment profiles reflecting important and differentiating attributes of GLP-1RAs. Eight attributes were included: efficacy, side effects, device size, needle size, titration, preparation, evidence of long-term efficacy/safety, and dosing frequency. Odds ratios (ORs) and 95% confidence intervals were calculated using a conditional logit model to indicate the likelihood of choosing a treatment with a given attribute level versus a reference attribute level. The influence of individual attributes when considering full treatment profiles was examined using exenatide once weekly (QW) and liraglutide once daily (QD) as case examples.

RESULTS

A total of 1482 patients with T2DM completed the DCE survey. Side effects, efficacy, and dosing frequency were the three most important attributes influencing preferences; needle size, device size, and required preparation were least important. Total sample analysis indicated that a profile of GLP-1RA approximating exenatide QW (single pen) was preferred over a profile approximating liraglutide QD (OR 3.36; p < 0.001), when efficacy was assumed to be equal.

CONCLUSION

The most influential drivers of treatment preferences for a hypothetical GLP-RA profile were side effects, efficacy, and dosing frequency among injection-naïve T2DM patients. Preference elicitation can promote patient-centered care and inform new generations of T2DM treatments, which can lead to improved adherence and health outcomes.

Glucagon-Like Peptide-1 Receptor Agonist Treatment Attributes Important to Injection-Experienced Patients with Type 2 Diabetes Mellitus: A Preference Study in Germany and the United Kingdom

INTRODUCTION

This study assessed the relative importance of treatment-related attributes in influencing patient preferences for glucagon-like peptide-1 receptor agonists (GLP-1RAs) among injection-experienced type 2 diabetes mellitus (T2DM) patients in Germany and the United Kingdom.

METHODS

T2DM patients experienced with injecting once-weekly (QW) exenatide or once-daily (QD) liraglutide completed an online discrete-choice experiment (DCE) survey. Patients chose between hypothetical blinded treatment profiles reflecting attributes of GLP-1RAs. The DCE survey included eight attributes: efficacy, side effects, device size, needle size, titration, injection preparation, long-term efficacy/safety, and dosing frequency. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a conditional logit model indicating the likelihood of choosing a treatment with a given attribute level versus a reference attribute level.

RESULTS

510 GLP-1RA injection-experienced patients completed the survey; 45.3% respondents were being treated with exenatide QW and 54.7% respondents were being treated with liraglutide QD. In terms of GLP-1RA attributes, patients indicated a preference for a treatment with greater efficacy (i.e., a 1.5-point improvement in HbA1c) (OR 2.58; 95% CI 2.37, 2.80; p < 0.001), fewer side effects (OR 2.67; 95% CI 2.52, 2.82; p < 0.001), once-weekly rather than once-daily administration (OR 2.26; 95% CI 2.13, 2.39; p < 0.001), and the preparation required for a multi-use pen (OR 1.71; 95% CI 1.55, 1.88; p < 0.001). Needle size, device size, and titration were not significant drivers of patient preference.

CONCLUSIONS

Among GLP-1RA injection-experienced patients, key drivers of treatment preference for a hypothetical GLP-RA profile were side effects, efficacy, dosing frequency, and required preparation. Understanding patient preferences is important for optimizing treatment decision-making and improving treatment adherence.

FUNDING

AstraZeneca.

A Network Meta-analysis Comparing Exenatide Once Weekly with Other GLP-1 Receptor Agonists for the Treatment of Type 2 Diabetes Mellitus

INTRODUCTION

Exenatide is a glucagon-like peptide-1 receptor agonist (GLP-1 RA), approved for treatment of type 2 diabetes mellitus (T2DM). There is limited direct evidence comparing the efficacy and tolerability of exenatide 2 mg once weekly (QW) to other GLP-1 RAs. A network meta-analysis (NMA) was conducted to estimate the relative efficacy and tolerability of exenatide QW versus other GLP-1 RAs for the treatment of adults with T2DM inadequately controlled on metformin monotherapy.

METHODS

A systematic literature review was conducted to identify randomized controlled trials (RCTs) that investigated GLP-1 RAs (albiglutide, dulaglutide, exenatide, liraglutide, and lixisenatide) at approved doses in the United States/Europe, added on to metformin only and of 24 ± 6 weeks treatment duration. A Bayesian NMA was conducted.

RESULTS

Fourteen RCTs were included in the NMA. Exenatide QW obtained a statistically significant reduction in glycated hemoglobin (HbA1c) relative to lixisenatide 20 µg once daily. No other comparisons of exenatide QW to other GLP-1 RAs were statistically significant for change in HbA1c. No statistically significant differences in change in weight, systolic blood pressure, risk of nausea or discontinuation due to adverse events were observed for exenatide QW versus other GLP-1 RAs.

CONCLUSION

Exenatide QW demonstrated similar effectiveness and tolerability compared to other GLP-1 RAs, for the treatment of T2DM in adults inadequately controlled on metformin alone.