The Role of Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes in Asia

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.

Cinchonine, a Potential Oral Small-Molecule Glucagon-Like Peptide-1 Receptor Agonist, Lowers Blood Glucose and Ameliorates Non-Alcoholic Steatohepatitis

Purpose

The glucagon-like peptide-1 receptor (GLP-1R) is an effective therapeutic target for type 2 diabetes mellitus (T2DM) and non-alcoholic steatohepatitis (NASH). Research has focused on small-molecule GLP-1R agonists because of their ease of use in oral formulations and improved patient compliance. However, no small-molecule GLP-1R agonists are currently available in the market. We aimed to screen for a potential oral small-molecule GLP-1R agonist and evaluated its effect on blood glucose and NASH.

Methods

The Connectivity map database was used to screen for candidate small-molecule compounds. Molecular docking was performed using SYBYL software. Rat pancreatic islets were incubated in different concentrations glucose solutions, with cinchonine or Exendin (9-39) added to determine insulin secretion levels. C57BL/6 mice, GLP-1R^-/- mice and hGLP-1R mice were used to conduct oral glucose tolerance test. In addition, we fed ob/ob mice with the GAN diet to induce the NASH model. Cinchonine (50 mg/kg or 100 mg/kg) was administered orally twice daily to the mice. Serum liver enzymes were measured using biochemical analysis. Liver tissues were examined using Hematoxylin-eosin staining, Oil Red O staining and Sirius Red staining.

Results

Based on the small intestinal transcriptome of geniposide, a recognized small-molecule GLP-1R agonist, we identified that cinchonine exerted GLP-1R agonist-like effects. Cinchonine had a good binding affinity for GLP-1R. Cinchonine promoted glucose-dependent insulin secretion, which could be attenuated significantly by Exendin (9-39), a specific GLP-1R antagonist. Moreover, cinchonine could reduce blood glucose in C57BL/6 and hGLP-1R mice, an effect that could be inhibited with GLP-1R knockout. In addition, cinchonine reduced body weight gain and food intake in ob/ob-GAN NASH mice dose-dependently. 100 mg/kg cinchonine significantly improved liver function by reducing the ALT, ALP and LDH levels. Importantly, 100 mg/kg cinchonine ameliorated hepatic steatosis and fibrosis in NASH mice.

Conclusion

Cinchonine, a potential oral small-molecule GLP-1R agonist, could reduce blood glucose and ameliorate NASH, providing a strategy for developing small-molecule GLP-1R agonists.

Real-World Comparative Evaluation of Add-On Glucagon-like Peptide 1 Receptor Agonist in Type 2 Diabetes Treated with or without Insulin

Glucagon-like peptide 1 receptor agonist (GLP-1 RA) is a potent antidiabetic agent with cardiorenal and weight-losing benefits in patients with type 2 diabetes (T2D). The combination of GLP-1 RA with basal insulin has been suggested in several clinical studies as a useful treatment for intensifying insulin therapy in T2D. However, there has been no real-world evidence study comparing the glycemic effects of GLP-1 RAs add-on to background treatment with and without insulin. A retrospective study was performed in 358 patients with T2D who initiated liraglutide or dulaglutide. Among them, 147 patients were prior and concurrent insulin users, and 211 patients were non-insulin users. After 12 months of GLP-1 RA treatment, the changes in hemoglobin A1c (HbA1C) and body weight were evaluated. The effectiveness of GLP-1 RAs on HbA1C reduction was greater in insulin users than non-insulin users at 12 months (−1.17% vs. −0.76%; p = 0.018). There was no significant difference in body weight change between insulin users and non-insulin users at 12 months (−1.42 kg vs. −1.87 kg; p = 0.287). The proportion of responders (decrease of HbA1C > 1%) in insulin users was much higher than that in non-insulin users (48% vs. 37 %; p = 0.04). In insulin users, those who had increased insulin dosage at 12 months had significantly less HbA1C reduction than that of non-increased patients (−0.62% vs. −1.57%; p = 0.001). GLP-1 RAs provide superior glucose-lowering effects in insulin-treated patients compared with non-insulin-treated patients with T2D without significant differences in body weight decrease.

Real-World Efficacy and Safety of Dulaglutide in Korean Patients with Type 2 Diabetes Mellitus: A Retrospective Study in a Tertiary Referral Center

This study was conducted to evaluate the efficacy and safety of once-weekly dulaglutide therapy as add-on to oral antidiabetic drugs (OADs) and basal insulin in Korean patients with type 2 diabetes mellitus (T2DM) in real-world clinical practice. We retrospectively reviewed the medical records of 112 patients who received dulaglutide in a tertiary referral center. The primary efficacy endpoint was a change in glycated hemoglobin (HbA1c) between baseline and 6 months. The secondary endpoints were the percentage of patients achieving HbA1c <7.0% or ≤6.5% and the change of body weight at 6 months. At baseline, the mean HbA1c was 8.7 % (8.8% in the OAD combination and 8.5% in the basal insulin combination group). The mean adjusted HbA1c at 6 months decreased by -1.13% in all patients (p<0.001), and by -1.36 and -0.74% in the OAD combination and basal insulin combination group, respectively. A significant reduction of -2.9 kg in body weight was observed in all patients at 6 months (p<0.001). Approximately 34.8% and 23.2% of patients achieved HbA1c <7.0% and ≤6.5%, respectively. Higher baseline HbA1c and no previous insulin therapy were associated with positive responses to dulaglutide on multivariate analysis. Mild gastrointestinal issues (23.2%) were the most frequently observed adverse events. Dulaglutide is an effective and durable treatment option as OAD and basal insulin combination therapy in Korean patients with T2DM.

Ultrasound-Targeted Microbubble Destruction Mediates Gene Transfection for Beta-Cell Regeneration and Glucose Regulation

Ultrasound-targeted microbubble destruction (UTMD) mediates gene transfection with high biosafety and thus has been promising toward treatment of type 1 diabetes. However, the potential application of UTMD in type 2 diabetes (T2D) is still limited, due to the lack of systematic design and dynamic monitoring. Herein, an efficient gene delivery system is constructed by plasmid deoxyribonucleic acid (DNA) encoding glucagon-like peptide 1 (GLP-1) in ultrasound-induced microbubbles, toward treatment of T2D in macaque. The as designed UTMD afforded enhancement of cell membrane penetration and GLP-1 expression in macaque, which is characterized by ultrasound-guided biopsy to monitor the dynamic process of islet cells for 6 months. Also, improvement of pancreatic beta cell regeneration, and regulation of plasma glucose in macaque with T2D is achieved. The approach would serve as promising alternatives for the treatment of T2D.

Efficacy and Safety of Dulaglutide Monotherapy Compared to Glimepiride in Oral Antihyperglycemic Medication-Naïve Chinese patients with Type 2 Diabetes: A Post Hoc Analysis of AWARD-CHN1

INTRODUCTION

Glucagon-like peptide (GLP)-1 receptor agonists are glucose-lowering agents associated with weight loss, cardiovascular benefits, and low hypoglycemic risk and are recommended by recent guidelines as first-line therapy for some patients with type 2 diabetes (T2D). This post hoc analysis of the AWARD-CHN1 study compared the efficacy and safety of once-weekly dulaglutide with glimepiride in oral antihyperglycemic medication (OAM)-naïve Chinese patients with T2D.

METHODS

AWARD-CHN1 was a phase 3, double-blind study with 737 patients randomized 1:1:1 to once-weekly dulaglutide (1.5 or 0.75 mg) or glimepiride (1-3 mg/day). This is a post hoc analysis of AWARD-CHN1 based on mixed-model repeated measures using a modified intent-to-treat analysis set with only the OAM-naïve Chinese population.

RESULTS

There were 264 OAM-naïve Chinese patients included in this analysis (dulaglutide 1.5 mg, n = 87; dulaglutide 0.75 mg, n = 90; glimepiride, n = 87). A greater glycated hemoglobin (HbA1c) reduction from baseline was observed with dulaglutide 1.5 mg and 0.75 mg compared to glimepiride (- 2.02% and - 1.84% vs - 1.37%, respectively; both P < 0.001). Significantly more patients in dulaglutide 1.5 mg and 0.75 mg groups achieved HbA1c targets < 7.0% compared to glimepiride (86.2% and 81.1% vs 65.5%; P = 0.002 and P = 0.026, respectively). Beta cell function was significantly increased for dulaglutide groups compared to glimepiride. Mean body weight was significantly reduced for dulaglutide 1.5 mg and 0.75 mg compared to glimepiride (- 1.40 kg and - 0.96 kg vs + 0.73 kg, respectively; both P < 0.001). Through 26 weeks, 7.9%, 4.2%, and 18.2% of patients reported hypoglycemia, and 40.4%, 23.2%, and 8.0% of patients reported at least one gastrointestinal treatment emergent adverse event, in dulaglutide 1.5 mg, 0.75 mg, and glimepiride groups, respectively.

CONCLUSIONS

In this post hoc analysis, dulaglutide was effective in reducing both HbA1c and weight with favorable tolerability and safety profile, which is consistent with results seen in larger international dulaglutide monotherapy studies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01644500.

Rapid gastric emptying in diabetes mellitus: Pathophysiology and clinical importance

Although slow gastric emptying (gastroparesis) is a well-known complication of chronic hyperglycemia in diabetes mellitus (DM), it recently has become clear that rapid gastric emptying also is a frequent and important diabetic complication. In contrast, acute hyperglycemia causes slow gastric emptying, and acute hypoglycemia causes rapid gastric emptying. Rapid gastric emptying is frequent in T2DM; however, it may also occur in T1DM, particularly in the early stages of the disease, but may persist even into late stages. Recent studies suggest that usually, the stomach restricts the emptying of nutrients to 1-4 kcals/min. This restriction is due to the action of the gastric 'braking' hormones such as GLP-1, leptin, and amylin acting via the gastric inhibitory vagal motor circuit (GIVMC). Disruption of this braking system leads to rapid gastric emptying. Acute hyperglycemia also slows gastric emptying by stimulating the GIVMC, while acute hypoglycemia causes rapid gastric emptying by stimulating the gastric excitatory vagal motor circuit (GEVMC). In contrast, chronic hyperglycemia causes rapid gastric emptying by inducing oxidative stress in the stomach wall that disrupts inhibitory neuromuscular transmission and increases the contractility of the smooth muscle, while chronic hyperglycemia may also cause slow gastric emptying via severe inflammatory stress caused by proinflammatory macrophages and reduce contractility of the smooth muscle. There is a bidirectional relationship between blood glucose and gastric emptying. Thus, rapid gastric emptying may lead to a sizeable postprandial spike, and slow gastric emptying may blunt it. Postprandial hyperglycemia is involved in the development, progression, and complications of DM. Correction of fast gastric emptying involves agents that activate GIVMC and the use of gastric 'braking' hormones or their analogs. Recognition and treatment of rapid gastric emptying may contribute to better management of postprandial hyperglycemia and prevention of some diabetic complications.

Clinical Efficacy and Parameters Affecting the Response to Dulaglutide Treatment in Patients with Type 2 Diabetes: A Retrospective, Real-World Data Study

INTRODUCTION

This study aimed to investigate the efficacy and clinical factors affecting the glycemic response to dulaglutide in type 2 diabetes (T2D) in a real-world clinical setting.

METHODS

We conducted a retrospective study of 234 patients at the Asan Medical Center, Republic of Korea, who had T2D and initiated dulaglutide from June 2016 to December 2017. The primary outcome was the change in glycated hemoglobin (HbA1c) concentration between baseline and 6 months after the initiation of therapy. Multivariate regression analysis was used to determine the clinical parameters contributing to a superior glycemic response to dulaglutide.

RESULTS

The mean age of the patients was 53, and 50% were male. Their mean baseline HbA1c, body mass index and duration of diabetes were 8.8%, 27.6 kg/m² and 10.2 years, respectively. The change in HbA1c between baseline and 6 months was - 0.92% (95% CI: - 1.1% to - 0.74%, p < 0.001). The reduction in body weight over the same period was -2.1 kg (95% CI: - 2.9 to - 1.3 kg, p < 0.001). Using multivariate regression analysis, baseline HbA1c was found to be a significant predictor of superior glycemic response to dulaglutide.

CONCLUSION

The use of dulaglutide was associated with a significant reduction in HbA1c and body weight over a 6-month period in a real-world clinical setting. T2D patients with higher baseline HbA1c concentrations were more likely to demonstrate good clinical responses to dulaglutide.