Differential effects of once-weekly glucagon-like peptide-1 receptor agonist dulaglutide and metformin on pancreatic β-cell and insulin sensitivity during a standardized test meal in patients with type 2 diabetes

β-cell neogenesis: A rising star to rescue diabetes mellitus

BACKGROUND

Diabetes Mellitus (DM), a chronic metabolic disease characterized by elevated blood glucose, is caused by various degrees of insulin resistance and dysfunctional insulin secretion, resulting in hyperglycemia. The loss and failure of functional β-cells are key mechanisms resulting in type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM).

AIM OF REVIEW

Elucidating the underlying mechanisms of β-cell failure, and exploring approaches for β-cell neogenesis to reverse β-cell dysfunction may provide novel strategies for DM therapy.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Emerging studies reveal that genetic susceptibility, endoplasmic reticulum (ER) stress, oxidative stress, islet inflammation, and protein modification linked to multiple signaling pathways contribute to DM pathogenesis. Over the past few years, replenishing functional β-cell by β-cell neogenesis to restore the number and function of pancreatic β-cells has remarkably exhibited a promising therapeutic approach for DM therapy. In this review, we provide a comprehensive overview of the underlying mechanisms of β-cell failure in DM, highlight the effective approaches for β-cell neogenesis, as well as discuss the current clinical and preclinical agents research advances of β-cell neogenesis. Insights into the challenges of translating β-cell neogenesis into clinical application for DM treatment are also offered.

Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus

Islet β-cell dysfunction is a basic pathophysiological characteristic of type 2 diabetes mellitus (T2DM). Appropriate assessment of islet β-cell function is beneficial to better management of T2DM. Protecting islet β-cell function is vital to delay the progress of type 2 diabetes mellitus. Therefore, the Pancreatic Islet β-cell Expert Panel of the Chinese Diabetes Society and Endocrinology Society of Jiangsu Medical Association organized experts to draft the "Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus." This consensus suggests that β-cell function can be clinically assessed using blood glucose-based methods or methods that combine blood glucose and endogenous insulin or C-peptide levels. Some measures, including weight loss and early and sustained euglycemia control, could effectively protect islet β-cell function, and some newly developed drugs, such as Sodium-glucose cotransporter-2 inhibitor and Glucagon-like peptide-1 receptor agonists, could improve islet β-cell function, independent of glycemic control.

Change in pharmacodynamic variables following once-weekly tirzepatide treatment versus dulaglutide in Japanese patients with type 2 diabetes (SURPASS J-mono substudy)

AIM

To evaluate the pharmacodynamic effects of tirzepatide, a novel dual glucagon-like peptide-1 receptor and glucose-dependent insulinotropic polypeptide receptor agonist, compared with dulaglutide in patients with type 2 diabetes.

MATERIALS AND METHODS

SURPASS J-mono was a 52-week, multicentre, randomized, double-blind, parallel, active-controlled, Phase 3 study, conducted in Japan. This substudy of SURPASS J-mono evaluated postprandial metabolic variables and appetite after a meal tolerance test, and body composition measured by bioelectrical impedance analysis.

RESULTS

Of 636 participants in SURPASS J-mono, 48 were included in this substudy and assigned to tirzepatide 5 mg (n = 9), tirzepatide 10 mg (n = 11), tirzepatide 15 mg (n = 9), or dulaglutide 0.75 mg (n = 19). Participants had a mean (standard deviation) age of 58.6 (7.5) years, duration of diabetes of 6.0 (6.3) years, and body mass index of 27.5 (3.5) kg/m² . Mean glycated haemoglobin at baseline was 66 mmol/mol (8.22%). Following a standardized meal test, statistically significant differences in change from baseline in area under the concentration versus time curve from time zero to 6 h after dose for glucose, insulin, glucagon, C-peptide and triglycerides were observed in all tirzepatide treatment arms, except triglycerides at 10 mg, compared with dulaglutide at Week 32. For body composition, tirzepatide 10 mg and 15 mg resulted in a significant reduction in body weight, and all doses of tirzepatide resulted in a significant reduction in body fat mass at Week 52.

CONCLUSIONS

Compared with dulaglutide, tirzepatide showed greater potential for normalizing metabolic factors after a standardized meal. Tirzepatide reduced body weight and body fat mass.

LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept

With an increasing prevalence of obesity, there is a need for new therapies to improve body weight management and metabolic health. Multireceptor agonists in development may provide approaches to fulfill this unmet medical need. LY3437943 is a novel triple agonist peptide at the glucagon receptor (GCGR), glucose-dependent insulinotropic polypeptide receptor (GIPR), and glucagon-like peptide-1 receptor (GLP-1R). In vitro, LY3437943 shows balanced GCGR and GLP-1R activity but more GIPR activity. In obese mice, administration of LY3437943 decreased body weight and improved glycemic control. Body weight loss was augmented by the addition of GCGR-mediated increases in energy expenditure to GIPR- and GLP-1R-driven calorie intake reduction. In a phase 1 single ascending dose study, LY3437943 showed a safety and tolerability profile similar to other incretins. Its pharmacokinetic profile supported once-weekly dosing, and a reduction in body weight persisted up to day 43 after a single dose. These findings warrant further clinical assessment of LY3437943.

Association of Dulaglutide Initiation Timing With Treatment Patterns and Clinical Outcomes in Patients With Type 2 Diabetes Mellitus in the United States

PURPOSE

To describe clinical characteristics and treatment outcomes for early or late initiation of dulaglutide therapy in patients with type 2 diabetes.

METHODS

This retrospective, claims-based analysis evaluated adults with type 2 diabetes, ≥1 claim for dulaglutide 0.75 mg or 1.5 mg once-weekly injection (between November 2014 and August 2019), and no prior use of glucagon-like peptide 1 receptor agonists or insulin. Cohorts were defined based on the number of oral antidiabetic drug (OAD) classes used within the 24-month baseline period before dulaglutide therapy initiation: 1 OAD, 2 OADs, or ≥3 OADs. The number of OAD classes used before dulaglutide therapy initiation served as a proxy for timing of initiation, with a higher number of OAD classes indicating a longer duration of T2D. Baseline demographic and clinical characteristics were compared across each cohort. Six-month follow-up outcomes, including change in glycosylated hemoglobin (HbA_1c) and treatment patterns, were descriptively assessed within each cohort.

FINDINGS

The study population consisted of 18,121 patients across the 1 OAD (n = 4822), 2 OADs (n = 6293), and ≥3 OADs (n = 7006) cohorts. Mean age at baseline was 54.7 years. Males were more prevalent in the ≥3 OADs cohort. Most patients (67%-70%) initiated treatment with dulaglutide 0.75 mg. Dose escalation to 1.5 mg was uncommon (15%-20%) but trended higher in the ≥3 OAD cohort. Adherence to dulaglutide at 6-month follow-up (61%-67%) increased with higher baseline OAD use. The HbA_1c assessment (n = 3178) included 761 patients in the 1 OAD cohort, 1088 patients in the 2 OADs cohort, and 1329 patients in the ≥3 OADs cohort. Baseline mean [SD] HbA_1c level increased with number of OAD classes (1 OAD: 8.18% [1.80]; 2 OADs: 8.56% [1.66]; and ≥3 OADs: 8.73% [1.51]). Patients in the early dulaglutide therapy initiator group experienced larger reductions in HbA_1c levels (1 OAD: -1.39%; 95% CI, -1.50 to -1.27; 2 OADs: -1.30%; 95% CI, -1.39 to -1.20; and ≥3 OADs: -1.01%; 95% CI, -1.09 to -0.93) versus the patients in the delayed initiator group. Patients in the early dulaglutide therapy initiator group also achieved HbA_1c <7% at 6-month follow-up more frequently than those in the later initiator group (1 OAD: 68%; 2 OADs: 51%; and ≥3 OADs: 33%).

IMPLICATIONS

Cohorts of dulaglutide therapy initiators, defined by prior OAD use as a proxy of timing of initiation, differed in their baseline characteristics and short-term follow-up outcomes. Earlier dulaglutide therapy initiation was associated with lower mean HbA_1c levels and increased probability of achievement of HbA_1c <7% during the 6-month follow-up period.

Exploring a Suitable Marker of Glycemic Response to Dulaglutide in Patients with Type 2 Diabetes: A Retrospective Study

INTRODUCTION

Previous studies suggested that β-cell function markers such as fasting and postprandial serum C-peptide and C-peptide increment (FCPR, PCPR, and ΔCPR, respectively) may be useful in estimating glycemic response to glucagon-like peptide-1 receptor agonists. However, it remains elusive whether baseline glycemic control confounds these markers. Here we aimed to identify the least confounded β-cell function markers and investigate whether these markers could predict glycemic response to dulaglutide.

METHODS

We evaluated FCPR, PCPR, and ΔCPR levels in patients with type 2 diabetes who initiated dulaglutide treatment after a standardized meal tolerance test (MTT). We first investigated the confounding effects of baseline HbA1c on β-cell function markers using Pearson's correlation test. Then, we evaluated the association between each β-cell function marker and glycemic response (HbA1c change 0-6 months) to dulaglutide using generalized linear model and logistic regression analysis with adjustment for baseline HbA1c.

RESULTS

In 141 patients, baseline HbA1c was significantly inversely correlated with PCPR and ΔCPR (P < 0.01 for both) but not with FCPR (r = 0.02; P = 0.853), suggesting that FCPR was the marker least confounded by baseline glycemic control. Of all patients, 59 continued dulaglutide for at least 6 months without initiating any additional glucose-lowering medications. Mean ± SE HbA1c change 0-6 months was - 1.16 ± 0.17% (P < 0.001 vs. baseline). The β-cell function markers were significantly associated with HbA1c change 0-6 months in the generalized linear model. FCPR was also a significant predictor for achieving a reduction in HbA1c of at least 1% (P = 0.044) with an area under the receiver operating characteristic curve of 0.83 (sensitivity = 0.81 and specificity = 0.79).

CONCLUSION

Fasting and meal-induced C-peptide levels are associated with glycemic response to dulaglutide, among which FCPR is least confounded by baseline glycemic control, suggesting its utility as a marker for glycemic response to dulaglutide.

Effect of Metformin Intervention on Pancreatic β-Cell Apoptosis

Metformin is shown to have hypoglycemic effects. However, the relationship between metformin’s intervention in FFA-induced endoplasmic reticulum stress-mediated insulin resistance (IR) and insulin β-cell apoptosis under high-glucose condition remains unclear. Our study intends to assess their relationship. Human pancreatic β-cells were treated with metformin and cell proliferation and IR were detected by MTT assay along with detection of Wnt/β-catenin signaling by RT-PCR, cell cycle and apoptosis by flow cytometry. Metformin inhibited β cell proliferation which was mediated by FFA-induced endoplasmic reticulum stress in a time-dependent and dose-dependent manner as well as induced cell cycle arrest at G2/M phase. In addition, metformin inhibited β-catenin signaling activation and decreased the expression of c-myc, Dvl-2, survivin, Dvl-3, GSK-3β (p-ser9) and promoted GSK-3 (p-tyr216) and Axin-2 expression. In conclusion, metformin inhibits Wnt/β-catenin signaling and promotes FFA to induce endoplasmic reticulum stress, thereby mediating pancreatic β-cells behaviors.

Incretins in the Therapy of Diabetic Kidney Disease

Diabetic kidney disease is a microvascular complication that occurs in patients with diabetes. It is strongly associated with increased risk of kidney replacement therapy and all-cause mortality. Incretins are peptide hormones derived from the gastrointestinal tract, that besides causing enhancement of insulin secretion after oral glucose intake, participate in many other metabolic processes. Antidiabetic drug classes, such as dipeptidyl peptidase 4 inhibitors and glucagon-like peptide receptor agonists, which way of action is based on incretins facility, not only show glucose-lowering properties but also have nephroprotective functions. The aim of this article is to present the latest information about incretin-based therapy and its influence on diabetic kidney disease appearance and progression, point its potential mechanisms of kidney protection and focus on future therapeutic possibilities bound with these two antidiabetic drug classes.

Everestmab, a novel long-acting GLP-1/anti GLP-1R nanobody fusion protein, exerts potent anti-diabetic effects

In the present study, a novel single domain antibody (sdAb) fusion protein, named everestmab, composing of a mutated GLP-1(A8G) fused to the tandem bispecific humanized GLP-1R-targeting and albumin-binding nanobodies was designed and characterized for the therapies for type 2 diabetes mellitus (T2DM). Surface plasmon resonance (SPR) measurements demonstrated everestmab associates with serum albumins of rat and monkey species with high affinity, and tends to be cross-reactive with rat and monkey species. In vitro GLP-1R binding and activation assays revealed that everestmab can specifically activate the GLP-1R, and the antagonist exendin-4 (9-39) did not inhibit the activation yet. In vivo multiple oral glucose tolerance tests (OGTTs) and hypoglycaemic efficacy tests proved that a single injection of everestmab reduced the blood glucose for at least 144 h in Goto-Kakizaki (GK) rats. The plasma half-lives of 4.1 and 7.8 days were observed after a single s.c. administration of everestmab in SD rats and cynomolgus monkeys, respectively. Chronic treatment of everestmab to GK and diet induced obese (DIO) rats achieved beneficial effects on weight reducing, HbA1c lowering, glucose tolerance, liver and pancreas islet function impairment. In summary, everestmab is a unique G-protein-coupled receptor-targeted nanobody fusion protein and exerts potential as a therapeutic treatment for T2DM.

Incretin Hormones and Type 2 Diabetes-Mechanistic Insights and Therapeutic Approaches

Simple Summary

When we ingest a meal, our intestine secretes hormones that are released into the bloodstream. Amongst these hormones are the incretins hormones which stimulate the release of insulin from the pancreas which is essential for the regulation of in particular postprandial glucose concentrations. In patients with type 2 diabetes, the effect of the incretins is diminished. This is thought to contribute importantly to the pathophysiology of the disease. However, in pharmacological amounts, the incretins may still influence insulin secretion and metabolism. Much research has therefore been devoted to the development of incretin-based therapies for type 2 diabetes. These therapies include compounds that strongly resemble the incretins, hereby stimulating their effects as well as inhibitors of the enzymatic degradation of the hormones, thereby increasing the concentration of incretins in the blood. Both therapeutic approaches have been implemented successfully, but research is still ongoing aimed at the development of further optimized therapies.

Abstract

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted from the gut upon nutrient stimulation and regulate postprandial metabolism. These hormones are known as classical incretin hormones and are responsible for a major part of postprandial insulin release. The incretin effect is severely reduced in patients with type 2 diabetes, but it was discovered that administration of GLP-1 agonists was capable of normalizing glucose control in these patients. Over the last decades, much research has been focused on the development of incretin-based therapies for type 2 diabetes. These therapies include incretin receptor agonists and inhibitors of the incretin-degrading enzyme dipeptidyl peptidase-4. Especially the development of diverse GLP-1 receptor agonists has shown immense success, whereas studies of GIP monotherapy in patients with type 2 diabetes have consistently been disappointing. Interestingly, both GIP-GLP-1 co-agonists and GIP receptor antagonists administered in combination with GLP-1R agonists appear to be efficient with respect to both weight loss and control of diabetes, although the molecular mechanisms behind these effects remain unknown. This review describes our current knowledge of the two incretin hormones and the development of incretin-based therapies for treatment of type 2 diabetes.

Probing the characteristics and biofunctional effects of disease-affected cells and drug response via machine learning applications

Drug-induced transformations in disease characteristics at the cellular and molecular level offers the opportunity to predict and evaluate the efficacy of pharmaceutical ingredients whilst enabling the optimal design of new and improved drugs with enhanced pharmacokinetics and pharmacodynamics. Machine learning is a promising in-silico tool used to simulate cells with specific disease properties and to determine their response toward drug uptake. Differences in the properties of normal and infected cells, including biophysical, biochemical and physiological characteristics, plays a key role in developing fundamental cellular probing platforms for machine learning applications. Cellular features can be extracted periodically from both the drug treated, infected, and normal cells via image segmentations in order to probe dynamic differences in cell behavior. Cellular segmentation can be evaluated to reflect the levels of drug effect on a distinct cell or group of cells via probability scoring. This article provides an account for the use of machine learning methods to probe differences in the biophysical, biochemical and physiological characteristics of infected cells in response to pharmacokinetics uptake of drug ingredients for application in cancer, diabetes and neurodegenerative disease therapies.

Effect of Once-Weekly Dulaglutide on Glucose Levels in Japanese Patients with Type 2 Diabetes: Findings from a Phase 4, Randomized Controlled Trial

INTRODUCTION

Dulaglutide is a recombinant glucagon-like peptide-1 immunoglobulin G4 Fc fusion protein approved for treating patients with type 2 diabetes (T2D). The aim of this study was to assess postprandial data over 4 weeks for dulaglutide (0.75 mg) versus placebo after a standardized test meal in Japanese patients with T2D.

METHODS

The pharmacodynamic (PD) effects of once-weekly dulaglutide (0.75 mg) in Japanese patients with T2D on diet and exercise therapy (N = 12) were evaluated by assessing postprandial data up to week 4 in a phase 4, single-center, randomized, cross-over, single-blind, placebo-controlled study. The primary end point was the change in 4-h glucose area under the concentration versus time curve [AUC (0-4 h)] from baseline to week 4. Secondary end points included changes from baseline in other PD parameters (insulin, C-peptide, glucagon, and triglycerides) at weeks 1, 2, and 4 and the safety and tolerability of dulaglutide 0.75 mg. Continuous glucose monitoring (CGM) during the 1st week was performed as an exploratory measure in each treatment period.

RESULTS

The decrease in AUC (0-4 h) from baseline to week 4 following dulaglutide administration was statistically significant compared with placebo at weeks 1, 2, and 4 (P < 0.0001). Insulin and C-peptide levels were also significantly increased (P < 0.05) with dulaglutide versus placebo at weeks 2 and 4. There were no statistically significant differences between groups in glucagon and triglyceride levels. Daily average glucose concentrations were decreased on the day after the first administration of dulaglutide and remained at similar levels for 4 days. The incidence of treatment-emergent adverse events was slightly higher with dulaglutide versus placebo.

CONCLUSION

In conclusion, dulaglutide decreased postprandial glucose from week 1 in Japanese patients with T2D, indicating that dulaglutide treatment is associated with favorable PD effects soon after treatment begins.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03315780.

FUNDING

Eli Lilly Japan K.K. (Kobe, Japan).

A Randomized Study to Compare the Effects of Once-Weekly Dulaglutide Injection and Once-Daily Glimepiride on Glucose Fluctuation of Type 2 Diabetes Mellitus Patients: A 26-Week Follow-Up

OBJECTIVE

To evaluate the effects of once-weekly dulaglutide injection and once-daily glimepiride on glucose fluctuation in patients with type 2 diabetes mellitus (T2DM) using the Continuous Glucose Monitoring System (CGMS).

METHODS

A total of 23 patients with T2DM were randomly assigned into two groups for 26 weeks: the dulaglutide group (n = 13) and the glimepiride group (n = 10). 72-hour CGMS was applied to all patients: before and after the treatment. General clinical data were collected and measured, such as fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), tumor necrosis factor-α (TNF-α), 8-iso-prostaglandin F2α (8-iso-PGF2α), and interleukin-6 (IL-6).

RESULTS

HbA1c of the dulaglutide group was reduced from 8.38 ± 0.93% to 6.68 ± 0.73% after the treatment (P < 0.05); similarly, it was reduced from 7.91 ± 0.98% to 6.67 ± 0.74% (P < 0.05) in the glimepiride group. The levels of serum 8-iso-PGF2α, TNF-α, and IL-6 all decreased significantly in both groups after treatment, and there was no significant difference found between the two groups (P > 0.05). The Mean Blood Glucose (MBG) of the two groups declined significantly after therapy (P < 0.05). However, the Standard Deviation of Blood Glucose (SDBG) decreased significantly only in the dulaglutide group (from 2.57 ± 0.74 mmol/L to 1.98 ± 0.74 mmol/L, P < 0.05). There were no significant changes of Mean Amplitude of Glycemic Excursion (MAGE) and Absolute Means of Daily Difference (MODD) after treatment in both groups. Furthermore, no statistically significant difference was found between the two groups in MBG, SDBG, MAGE, and MODD (P > 0.05). The percentage time (PT) (>10 mmol/L and 3.9-10 mmol/L) of the two groups was significantly changed after the treatment (P < 0.05). However, this was not seen in the PT < 3.9 mmol/L after the treatment (P > 0.05).

CONCLUSION

Once-weekly dulaglutide injection has the same effectiveness as daily glimepiride on lowering blood glucose and decreasing oxidation stress and inflammation and is more effective in controlling glucose fluctuation as compared with glimepiride. This trial is registered with ClinicalTrials.gov NCT01644500.

Effect of once weekly dulaglutide by baseline beta-cell function in people with type 2 diabetes in the AWARD programme

Glucagon-like peptide-1 receptor agonists lower blood glucose in type 2 diabetes (T2D) partially through glucose-dependent stimulation of insulin secretion. The aim of this study was to investigate whether beta-cell function (as measured by HOMA2-%B) at baseline affects the glycaemic response to dulaglutide. Dulaglutide-treated patients from AWARD-1, AWARD-3 and AWARD-6 clinical studies were categorised based on their homeostatic model assessment of beta-cell function (HOMA2-%B) tertiles. Changes in glycaemic measures in response to treatment with once-weekly dulaglutide were evaluated in each HOMA2-%B tertile. Patients with low HOMA2-%B had higher baseline glycated haemoglobin (HbA1c), fasting and postprandial blood glucose, and longer duration of diabetes (P < .001, all) (mean low, middle and high tertiles with dulaglutide 1.5 mg: HOMAB-2%B, 31%, 58%, 109%; HbA1c, 8.7%, 7.7%, 7.3%, respectively). At 26 weeks, the low tertile experienced larger reductions in HbA1c compared to the high tertile with dulaglutide 1.5 mg (mean; -1.55% vs. -0.98% [-16.94 vs. -10.71 mmol/mol]). Differences between low and high tertiles disappeared when adjusted for baseline HbA1c (LSM; -1.00 vs. -1.18% [-10.93 vs. -12.90 mmol/mol]). Greater decreases in fasting blood glucose and greater increases in fasting C-peptide were observed in the low tertile. Similar increases in HOMA2-%B were observed in all tertiles. Dulaglutide demonstrated clinically relevant HbA1c reduction irrespective of estimated baseline beta-cell function.

Improving glycaemic control in type 2 diabetes: Stimulate insulin secretion or provide beta-cell rest?

Type 2 diabetes (T2D) is characterized by a gradual decline in pancreatic beta cell function that determines the progressive course of the disease. While beta-cell failure is an important contributor to hyperglycaemia, chronic hyperglycaemia itself is also detrimental for beta-cell function, probably by inducing prolonged secretory stress on the beta cell as well as through direct glucotoxic mechanisms that have not been fully defined. For years, research has been carried out in search of therapies targeting hyperglycaemia that preserve long-term beta-cell function in T2D, a quest that is still ongoing. Current strategies aim to improve glycaemic control, either by promoting endogenous insulin secretion, such as sulfonylureas, or by mechanisms that may impact the beta cell indirectly, for example, providing beta-cell rest through insulin treatment. Although overall long-term success is limited with currently available interventions, in this review we argue that strategies that induce beta-cell rest have considerable potential to preserve long-term beta-cell function. This is based on laboratory-based studies involving human islets as well as clinical studies employing intensive insulin therapy, thiazolidinediones, bariatric surgery, short-acting glucagon-like peptide (GLP)-1 receptor agonists and a promising new class of diabetes drugs, sodium-glucose-linked transporter (SGLT)-2 inhibitors. Nevertheless, a lack of long-term clinical studies that focus on beta-cell function for the newer glucose-lowering agents, as well as commonly used combination therapies, preclude a straightforward conclusion; this gap in our knowledge should be a focus of future studies.