Addition of exenatide twice daily to basal insulin for the treatment of type 2 diabetes: clinical studies and practical approaches to therapy

Efficacy and safety of PEGylated exenatide injection (PB-119) in treatment-naive type 2 diabetes mellitus patients: a Phase II randomised, double-blind, parallel, placebo-controlled study

AIMS/HYPOTHESIS

Glucagon-like peptide 1 receptor agonists (GLP-1 RA) such as exenatide are used as monotherapy and add-on therapy for maintaining glycaemic control in patients with type 2 diabetes mellitus. The current study investigated the safety and efficacy of once-weekly PB-119, a PEGylated exenatide injection, in treatment-naive patients with type 2 diabetes.

METHODS

In this Phase II, randomised, placebo-controlled, double-blind study, we randomly assigned treatment-naive Chinese patients with type 2 diabetes in a 1:1:1:1 ratio to receive subcutaneous placebo or one of three subcutaneous doses of PB-119 (75, 150, and 200 μg) for 12 weeks. The primary endpoint was the change in HbA_1c from baseline to week 12, and other endpoints were fasting plasma glucose, 2 h postprandial glucose (PPG), and proportion of patients with HbA_1c < 53 mmol/mol (<7.0%) and ≤48 mmol/mol (≤6.5%) at 2, 4, 8 and 12 weeks of treatment. Safety was assessed in all patients who received at least one dose of study drug.

RESULTS

We randomly assigned 251 patients to one of the four treatment groups (n = 62 in placebo and 63 each in PB-119 75 μg, 150 μg and 200 μg groups). At the end of 12 weeks, mean differences in HbA_1c in the treatment groups were -7.76 mmol/mol (95% CI -9.23, -4.63, p < 0.001) (-0.72%, 95% CI -1.01, -0.43), -12.89 mmol/mol (95% CI -16.05, -9.72, p < 0.001) (-1.18%, 95% CI -1.47, -0.89) and -11.14 mmol/mol (95% CI -14.19, -7.97, p <0 .001) (-1.02%, 95% CI -1.30, -0.73) in the 75 μg, 150 μg and 200 μg PB-119 groups, respectively, compared with that in the placebo group after adjusting for baseline HbA_1c. Similar results were also observed for other efficacy endpoints across different time points. There was no incidence of treatment-emergent serious adverse event, severe hypoglycaemia or death.

CONCLUSIONS/INTERPRETATION

All tested PB-119 doses had superior efficacy compared with placebo and were safe and well tolerated over 12 weeks in treatment-naive Chinese patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03520972 FUNDING: The study was funded by National Major Scientific and Technological Special Project for Significant New Drugs Development and PegBio.

The value of short- and long-acting glucagon-like peptide-1 agonists in the management of type 2 diabetes mellitus: experience with exenatide

BACKGROUND

Only about half of patients with type 2 diabetes treated with antihyperglycemic drugs achieve glycemic control (HbA1c <7%), most commonly due to poor treatment adherence. Glucagon-like peptide-1 (GLP-1) receptor agonists act on multiple targets involved in glucose homeostasis and have a low risk of causing hypoglycemia. While GLP-1 receptor (GLP-1R) agonists share the same mechanism of action, clinical profiles of individual agents differ, particularly between short- and long-acting agents. In this article, recent findings regarding the pharmacology of GLP-1 agonists are reviewed, and the clinical effects of short- versus long-acting agents are compared.

DATA SOURCES

Relevant articles were identified through a search of PubMed using the keywords glucagon-like peptide-1, GLP-1, glucagon-like peptide-1 receptor agonist, GLP-1R agonist, and exenatide for publications up to 22 May 2015. Supporting data were obtained from additional searches for albiglutide, dulaglutide, liraglutide and lixisenatide as well as from the bibliographies of key articles.

FINDINGS

Short-acting GLP-1R agonists produce greater reductions in postprandial glucose levels by slowing gastric emptying, whereas long-acting GLP-1R agonists produce greater reductions in fasting blood glucose by stimulating insulin secretion from the pancreas. These characteristics can be exploited to provide individualized treatment to patients. A large body of evidence supports the benefits of short- and long-acting exenatide as add-on therapy in patients with inadequate glycemic control despite maximum tolerated doses of metformin and/or sulfonylurea. Exenatide is generally well tolerated and no new safety concerns were identified during long-term follow-up of up to 5 years. A limitation of this review of short-and long-acting GLP-1 receptor agonists is that it focuses on exenatide rather than all the drugs in this class. However, the focus on a single molecule helps to avoid any confusion that may be introduced as a result of differences in molecular structure and size.

CONCLUSIONS

Short-acting GLP-1R agonists including exenatide are well suited to patients with type 2 diabetes with exaggerated postprandial glucose excursions and for co-administration with basal insulin therapy. Long-acting GLP-1R agonists including once weekly exenatide offer greater convenience and are well suited to patients who require specific control of fasting hyperglycemia.

Defining the role of GLP-1 receptor agonists for individualized treatment of Type 2 diabetes

With the advent of dipeptidyl peptidase (DPP)-4 inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) over the past decade, incretin therapy has become established as an important treatment strategy for Type 2 diabetes mellitus (T2DM), with an efficacy and safety profile distinct from that of other anti-hyperglycemic agents. However, our understanding of the optimal clinical use of incretins remains incomplete. This review focuses on the use of GLP-1 RAs in the treatment of T2DM, with reference to the differing dominant mechanisms of action between short- and long-acting GLP-1 RAs and the clinical implications of this difference. The role of GLP-1 and the effects of GLP-1 RAs in various organs other than the pancreas will also be discussed.

Basal insulin combined incretin mimetic therapy with glucagon-like protein 1 receptor agonists as an upcoming option in the treatment of type 2 diabetes: a practical guide to decision making

The combination of basal insulin and glucagon-like protein 1 receptor agonists (GLP-1 RAs) is a new intriguing therapeutic option for patients with type 2 diabetes. In our daily practice we abbreviate this therapeutic concept with the term BIT (basal insulin combined incretin mimetic therapy) in a certain analogy to BOT (basal insulin supported oral therapy). In most cases BIT is indeed an extension of BOT, if fasting, prandial or postprandial blood glucose values have not reached the target range. In our paper we discuss special features of combinations of short- or prandial-acting and long- or continuous-acting GLP-1 RAs like exenatide, lixisenatide and liraglutide with basal insulin in relation to different glycemic targets. Overall it seems appropriate to use a short-acting GLP-1 RA if, after the near normalization of fasting blood glucose with BOT, the prandial or postprandial values are elevated. A long-acting GLP-1 RA might well be given, if fasting blood glucose values are the problem. Based on pathophysiological findings, recent clinical studies and our experience with BIT and BOT as well as BOTplus we developed chart-supported algorithms for decision making, including features and conditions of patients. The development of these practical tools was guided by the need for a more individualized antidiabetic therapy and the availability of the new BIT principle.

Role of glucagon-like peptide-1 analogue versus amylin as an adjuvant therapy in type 1 diabetes in a closed loop setting with ePID algorithm

Postprandial hyperglycemia due to paradoxical hyperglucagonemia is a major challenge of diabetes treatment despite the use of the artificial pancreas. We postulated that adjunctive therapy with pramlintide or exenatide would attenuate hyperglycemia in the postprandial phase through glucagon suppression, thereby optimizing the functioning of the closed-loop (CL) system. Subjects with type 1 diabetes (T1DM) on insulin pump therapy were recruited to participate in a 27-hour hospitalized admission on 3 occasions (2-4 weeks apart) and placed on the insulin delivery via CL system in random order to receive (1) insulin alone (control), (2) exenatide 2.5 µg + insulin, (3) pramlintide 30 µg + insulin. Medications were given prior to lunch and dinner, which was a standardized meal of 60 grams of carbohydrates. Insulin delivery was as per the ePID algorithm via the Medtronic CL system and continuous subcutaneous glucose monitoring via Medtronic Sof-sensors. Ten subjects age 23 ± 1 years with a HbA1c of 7.29 ± 0.3% (56 ± 1 mmol/mol) and duration of T1DM 10.6 ± 2.0 years participated in the 3-part study. Exenatide was found to be significantly better in attenuating postprandial hyperglycemia as compared to insulin monotherapy (P < .03) and pramlintide (P > .05). Glucagon suppression was statistically significant with exenatide (P < .03) as compared to pramlintide. Insulin requirements were lower with adjunctive therapy, but statistically insignificant. Insulin monotherapy results in postprandial hyperglycemia in T1DM in the CL setting and adjunctive therapy with exenatide reduces postprandial hyperglycemia effectively and should be considered as adjunctive therapy in T1DM.

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

INTRODUCTION

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

METHODS

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

DISCUSSION

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

CONCLUSIONS

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

Options for prandial glucose management in type 2 diabetes patients using basal insulin: addition of a short-acting GLP-1 analogue versus progression to basal-bolus therapy

Integrating patient-centered diabetes care and algorithmic medicine poses particular challenges when optimized basal insulin fails to maintain glycaemic control in patients with type 2 diabetes. Multiple entwined physiological, psychosocial and systems barriers to insulin adherence are not easily studied and are not adequately considered in most treatment algorithms. Moreover, the limited number of alternatives to add-on prandial insulin therapy has hindered shared decision-making, a central feature of patient-centered care. This article considers how the addition of a glucagon-like peptide 1 (GLP-1) analogue to basal insulin may provide new opportunities at this stage of treatment, especially for patients concerned about weight gain and risk of hypoglycaemia. A flexible framework for patient-clinician discussions is presented to encourage development of decision-support tools applicable to both specialty and primary care practice.

Once weekly exenatide: efficacy, tolerability and place in therapy

Exenatide once weekly is the first glucose-lowering agent available to patients with type 2 diabetes mellitus (T2DM) which is administered once per week. This long-acting formulation contains the same active ingredient as exenatide twice daily, except that the exenatide is encapsulated in dissolvable microspheres. Following subcutaneous injection, exenatide once weekly microspheres remain in place under the skin and slowly degrade, releasing active exenatide continuously into circulation. In randomized clinical trials, exenatide once weekly was associated with significant glycaemic improvement and moderate weight loss in patients with T2DM when administered as monotherapy or in combination with a variety of oral antidiabetic agents. Exenatide once weekly also lowered blood glucose more effectively than titrated basal insulin in patients on metformin or metformin plus sulphonylurea background therapy. Gastrointestinal side effects (nausea, vomiting and diarrhoea) were the most common tolerability issues associated with exenatide once weekly administration, but they occurred at lower rates than in patients on other glucagon-like peptide receptor agonists (i.e., exenatide twice daily or liraglutide). Issues regarding the place of exenatide once weekly in T2DM pharmacotherapy are discussed.

Effects of exenatide and metformin in combination on some adipocytokine levels: a comparison with metformin monotherapy

The aim of this study was to evaluate the effects of exenatide on levels of serum adipocytokines and on β-cell function. The study was conducted between 2008 and 2012. After a run-in period with metformin, 174 patients with type-2 diabetes were randomly distributed to either a group receiving exenatide at 10 μg twice daily, or a group receiving the placebo, for 12 months. We evaluated body mass index (BMI), blood pressure, glycemic control, lipid profile, fasting plasma insulin (FPI), HOMA-IR, HOMA-β, fasting plasma proinsulin (FPPr), proinsulin : fasting plasma insulin ratio (Pr/FPI ratio), C-peptide, glucagon, retinol binding protein-4 (RBP-4), visfatin, omentin-1, and microalbuminuria. We used ELISA methods to assess the various parameters. Patients also underwent a combined euglycemic-hyperinsulinemic and hyperglycemic clamp, with subsequent arginine stimulation. After 12 months, a combination of exenatide and metformin produced a better decrease in body mass, BMI, glycemic control, FPI, FPPr, FPPr/FPI ratio, HOMA-IR, and glucagon level. Treatment with exenatide + metformin was superior to the placebo + metformin in increasing HOMA-β, C-peptide, and β-cell function. Significant negative correlations were found between M value, an index of insulin sensitivity, and measured adipocytokines. In conclusion, the combination of exenatide + metformin plays a role in improving some adipocytokine levels, and is better than metformin alone. The significant negative correlation between M value and measured adipocytokines is another confirmation of the positive effects linked to the improvement in insulin sensitivity.

Lixisenatide - A New Glucagon-like Peptide 1 Receptor Agonist in the Treatment of Type 2 Diabetes

Optimal glycaemic control is essential to managing risks in patients with type 2 diabetes. However, glycaemic control remains poor among type 2 diabetes patients, particularly the control of post-prandial glucose (PPG). Almost half of patients treated with basal insulin and oral anti-diabetic drugs (OADs) do not achieve their glycated haemoglobin (HbA1c) goals, despite achieving fasting plasma glucose (FPG) control. Glycaemic control targets have emphasised FPG targets, but PPG contributes significantly to overall glycaemic control in type 2 diabetes. Glucagon-like peptide 1 (GLP-1) receptor agonists have shown substantial efficacy in improving overall glycaemic control but have differing effects on PPG, which is a result of their different mechanisms of action. Lixisenatide is unique among existing GLP-1 receptor agonists in that it is short acting but given as a once daily dose, and exerts its main effects during the prandial period. It has demonstrated efficacy in an extensive clinical trial programme. In particular, it has shown a beneficial effect on PPG compared with existing GLP-1 receptor agonists, probably a result of its effect on slowing gastric emptying. This has provided a strong rationale for its use as add-on therapy to long-acting basal insulin analogues, in cases where the latter is not providing adequate glycaemic control. The additive effects on glycaemic control may lead to a new treatment approach to manage blood glucose and prevent long-term complications in patients with type 2 diabetes.