Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial

A Novel Dual Incretin Agent, Tirzepatide (LY3298176), for the treatment of Type 2 Diabetes Mellitus and Cardiometabolic Health

ABSTRACT

The incretin hormone system is the target of multiple type 2 diabetes mellitus (T2DM) treatments because defects in this system play major roles in the pathogenesis of diabetes. Currently, the glucagon-like peptide (GLP-1) receptor agonists are recommended for patients with atherosclerotic cardiovascular disease (ASCVD) and those at high risk for ASCVD. In addition to the favorable cardiovascular effects, GLP-1 RAs also provide robust lowering of hemoglobin A1c and weight. While these factors make GLP-1 RAs attractive options for T2DM, the currently available agents have no effect on glucose-dependent insulinotropic polypeptide (GIP). Patients with T2DM are known to have GIP defect which is significant due to its profound insulinotropic effects. Tirzepatide is a novel incretin agent currently under review by the Food and Drug Administration for the treatment of type 2 diabetes. This first-in-class agent serves as a co-agonist for both the GLP-1 and GIP receptors. In this review, we report on the pharmacologic mechanism of GLP-1, GIP and co-agonist effects on the cardiometabolic system. Additionally, we review the glycemic lowering, weight-loss effects, and other cardiometabolic outcomes of tirzepatide based on phase 2 and 3 data. The safety profile of tirzepatide is consistent across all phase 3 trials. The most common adverse effects are gastrointestinal symptoms, but they generally have a low risk for discontinuation. Overall, preliminary data suggests tirzepatide is an efficacious and safe agent for the treatment of T2DM.

Exit Interviews Examining the Patient Experience in Clinical Trials of Tirzepatide for Treatment of Type 2 Diabetes

Introduction

Qualitative exit interviews can supplement clinical trial results by providing a rich and detailed picture of the patient’s experience, while highlighting the treatment benefits that are meaningful to patients. Exit interviews can be particularly useful for providing insight into newer medications when less is known about the patient’s subjective experience of treatment. Tirzepatide is a novel dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist for type 2 diabetes mellitus. The purpose of this study was to conduct exit interviews with patients following participation in two trials to better understand the impact of tirzepatide from the patients’ point of view.

Methods

Telephone interviews were conducted with patients with type 2 diabetes treated with tirzepatide soon after completing one of two trials (SURPASS-2, SURPASS-3). Interviews, conducted according to a semi-structured interview guide, were recorded, transcribed, and analyzed following a content analysis approach using ATLAS.ti.

Results

A total of 28 patients (64% female; mean age 57.6 years) completed interviews. All participants (100%) reported at least one treatment benefit. Patients provided descriptions of treatment benefits, including improved glycemic control (reported by 96% of the sample), weight loss (93%), decreased appetite (79%), and increased energy (79%), as indicated by qualitative coding. All participants said these treatment-related changes mattered to them. Patients described improvements in quality of life and daily activities associated with these treatment benefits. Despite adverse events reported by some patients (most commonly nausea, reported by 13 patients), all 28 said they would recommend tirzepatide to others, and 27 said they would be willing to continue treatment. Examples of representative quotations are presented for descriptions of treatment benefits, quality-of-life impact, and adverse events.

Discussion

The current results indicate that treatment benefits observed in clinical trials of tirzepatide are important to patients. As demonstrated in quotations from patients, the most enthusiastic descriptions of treatment outcomes focused on the weight loss associated with tirzepatide. The study also highlights the usefulness of exit interviews, which can supplement quantitative trial data by showing how these benefits have a meaningful impact on patients’ quality of life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-022-00578-8.

GLP-1 and GIP receptor signaling in beta cells - A review of receptor interactions and co-stimulation

Glucagon-like peptide 1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are two class B1 G protein-coupled receptors, which are stimulated by the gastrointestinal hormones GLP-1 and GIP, respectively. In the pancreatic beta cells, activation of both receptors lead to increased cyclic adenosine monophosphate (cAMP) and glucose-dependent insulin secretion. Marketed GLP-1R agonists such as dulaglutide, liraglutide, exenatide and semaglutide constitute an expanding drug class with beneficial effects for persons suffering from type 2 diabetes and/or obesity. In recent years another drug class, the GLP-1R-GIPR co-agonists, has emerged. Especially the peptide-based, co-agonist tirzepatide is a promising candidate for a better treatment of type 2 diabetes by improving glycemic control and weight reduction. The mechanism of action for tirzepatide include biased signaling of the GLP-1R as well as potent GIPR signaling. Since the implications of co-targeting these closely related receptors concomitantly are challenging to study in vivo, the pharmacodynamic mechanisms and downstream signaling pathways of the GLP-1R-GIPR co-agonists in general, are not fully elucidated. In this review, we present the individual signaling pathways for GLP-1R and GIPR in the pancreatic beta cell with a focus on the shared signaling pathways of the two receptors and interpret the implications of GLP-1R-GIPR co-activation in the light of recent co-activating therapeutic compounds.

Managing weight and glycaemic targets in people with type 2 diabetes—How far have we come?

Introduction

As the vast majority of people with type 2 diabetes (T2D) are also overweight or obese, healthcare professionals (HCP) are faced with the task of addressing both weight management and glucose control. In this narrative review, we aim to identify the challenges of reaching and maintaining body weight targets in people with T2D and highlight current and future treatment interventions.

Methods

A search of the PubMed database was conducted using the search terms “diabetes” and “weight loss.”

Results

According to emerging evidence, treating obesity may be antecedent to the development and progression of T2D. While clinical benefits typically set in upon achieving a weight loss of 3–5%, these benefits are progressive leading to further health improvements, and weight loss of >15% can have a disease‐modifying effect in people with T2D, an outcome that up to recently could not be achieved with any blood glucose‐lowering pharmacotherapy. However, advanced treatment options with weight‐loss effects currently in development including the dual GIP/GLP‐1 receptor agonists may enable simultaneous achievement of individual glycemic and weight goals.

Conclusion

Despite considerable therapeutic progress, there is still a large unmet medical need in patients with T2D who miss their individualized glycemic and weight‐loss targets. Nonetheless, it is to be expected that development of future therapies and their use will favourably change the scenario of weight and glucose control in T2D.

Efficacy and safety of high-dose glucagon-like peptide-1, glucagon-like peptide-1/glucose-dependent insulinotropic peptide, and glucagon-like peptide-1/glucagon receptor agonists in type 2 diabetes

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have become agents of choice for people with type 2 diabetes (T2D) with established cardiovascular disease or in high-risk individuals. With currently available GLP-1 RAs, 51%-79% of subjects achieve an HbA1c target of less than 7.0% and 4%-27% lose 10% of body weight, illustrating the need for more potent agents. Three databases (PubMed, Cochrane, Web of Science) were searched using the MESH terms 'glucagon-like peptide-1 receptor agonist', 'glucagon receptor agonist', 'glucose-dependent insulinotropic peptide', 'dual or co-agonist', and 'tirzepatide'. Quality of papers was scored using PRISMA guidelines. Risk of bias was evaluated using the Cochrane assessment tool. An HbA1c target of less than 7.0% was attained by up to 80% with high-dose GLP-1 RAs and up to 97% with tirzepatide, with even up to 62% of people with T2D reaching an HbA1c of less than 5.7%. A body weight loss of 10% or greater was obtained by up to 50% and up to 69% with high-dose GLP-1 RAs or tirzepatide, respectively. The glucose- and weight-lowering effects of the GLP-1/glucagon RA cotadutide equal those of liraglutide 1.8 mg. Gastrointestinal side effects of high-dose GLP-1 RAs and co-agonists occurred in 30%-70% of patients, mostly arising within the first 2 weeks of the first dose, being mild or moderate in severity, and transient. The development of high-dose GLP-1 RAs and the dual GLP-1/glucose-dependent insulinotropic peptide RA tirzepatide resulted in increasing numbers of people reaching HbA1c and body weight targets, with up to 62% attaining normoglycaemia with 15-mg tirzepatide. Whether this will also translate to better cardiovascular outcomes and affect treatment guidelines remains to be studied.

Report from the CVOT Summit 2021: new cardiovascular, renal, and glycemic outcomes

The 7th Cardiovascular Outcome Trial (CVOT) Summit on Cardiovascular, Renal, and Glycemic Outcomes, was held virtually on November 18-19, 2021. Pursuing the tradition of the previous summits, this reference congress served as a platform for in-depth discussion and exchange on recently completed CVOTs. This year's focus was placed on the outcomes of EMPEROR-Preserved, FIGARO-DKD, AMPLITUDE-O, SURPASS 1-5, and STEP 1-5. Trial implications for diabetes and obesity management and the impact on new treatment algorithms were highlighted for endocrinologists, diabetologists, cardiologists, nephrologists, and general practitioners. Discussions evolved from outcome trials using SGLT2 inhibitors as therapy for heart failure, to CVOTs with nonsteroidal mineralocorticoid receptor antagonists and GLP-1 receptor agonists. Furthermore, trials for glycemic and overweight/obesity management, challenges in diabetes management in COVID-19, and novel guidelines and treatment strategies were discussed.Trial registration The 8th Cardiovascular Outcome Trial Summit will be held virtually on November 10-11, 2022 ( http://www.cvot.org ).

Long-acting amylin analogues for the management of obesity

PURPOSE OF REVIEW

To summarize recent developments of long-acting amylin analogues for the treatment of obesity and to outline their mode of action.

RECENT FINDINGS

Amylin is a pancreatic hormone acting to control energy homeostasis and body weight. Activity at the calcitonin and amylin receptors in the area postrema seems to - at least partly - be responsible for these effects of amylin. Both preclinical and early-stage clinical studies investigating long-acting amylin receptor analogues demonstrate beneficial effects on body weight in obesity. Cagrilintide, a novel amylin analogue suitable for once-weekly administration, is in phase II clinical development and has shown promising body weight reducing effects alone and in combination with the glucagon-like peptide 1 receptor agonist semaglutide.

SUMMARY

Long-acting amylin analogues have emerged as a possible pharmacotherapy against obesity, but more studies are needed to support the utility and long-term effects of this strategy in relevant populations.

The Upcoming Weekly Tides (Semaglutide vs. Tirzepatide) against Obesity: STEP or SURPASS?

The rapidly increasing prevalence of obesity and obesity-associated morbidity is causing an ever-increasing global burden. Beyond lifestyle modifications, pharmacological approaches to losing body weight to achieve a decrease in cardiometabolic complications are in the spotlight. Pre-existing anti-obesity medications (AOMs) approved for long-term prescription use showed a weight reduction of around 5% more than placebo. In contrast to the modest efficacy of pre-existing AOMs, two newly developed, weekly-administered injectable drugs, semaglutide and tirzepatide, exhibited outstanding weight-loss effects in a series of multinational randomized phase III trials. Considering that these two peptides are the most promising candidates for the upcoming battle in the anti-obesity market, comparison of their efficacy and safety is essential. This review summarizes the body weight reduction efficacy, glycemic control, and safety of semaglutide up to a 2.4-mg dose and tirzepatide up to a 15-mg dose, focusing on the Semaglutide Treatment Effect in People with Obesity (STEP) 2, SURPASS-1, and SURPASS-2 trials, the subjects of which were all patients with type 2 diabetes mellitus.

Management of Type 2 Diabetes in Stage C Heart Failure with Reduced Ejection Fraction

Type 2 diabetes is an increasingly common comorbidity of stage C heart failure with reduced ejection fraction (HFrEF). The two diseases are risk factors for each other and can bidirectionally independently worsen outcomes. The regulatory requirement of cardiovascular outcomes trials for antidiabetic agents has led to an emergence of novel therapies with robust benefits in heart failure, and clinicians must now ensure they are familiar with the management of patients with concurrent diabetes and stage C HFrEF. This review summarises the current evidence for the management of type 2 diabetes in stage C HFrEF, recapitulating data from landmark heart failure trials regarding the use of guideline-directed medical therapy for heart failure in patients with diabetes. It also provides a preview of upcoming clinical trials in these populations.

New Horizons. A New Paradigm for Treating to Target with Second-Generation Obesity Medications

In treating obesity as a chronic disease, the essential goal of weight loss therapy is not the quantity of weight loss as an end unto itself but rather the prevention and treatment of complications to enhance health and mitigate morbidity and mortality. This perspective on obesity care is consistent with the complications-centric American Association of Clinical Endocrinology (AACE) obesity guidelines and the diagnostic term of adiposity-based chronic disease (ABCD). Many complications require 10% to 20% weight loss to achieve therapeutic goals; however, existing obesity medications fail to produce ≥10% weight loss in the majority of patients. In June, 2021, semaglutide 2.4 mg/week was approved for chronic weight management. Phase 3 clinical trials demonstrated that this medication produced > 10% placebo-subtracted weight loss, more than half of patents lost ≥15%, and over one third lost ≥20% of baseline weight. This essentially doubles effectiveness over existing obesity medications, provides sufficient weight loss to ameliorate a broad range of complications, and qualifies as the first member of a second-generation class of obesity medications. The advent of second-generation medications fully enables a treat-to-target approach for management of ABCD as a chronic disease. Specifically, with this degree of efficacy, second-generation medications permit active management of body weight as a biomarker to targets associated with effective treatment and prevention of specific complications. ABCD can now be managed similar to other chronic diseases such as type 2 diabetes, hypertension, and atherosclerosis, which are treated to biomarker targets that can be modified based on the clinical status of individual patients [ie, hemoglobin A1c (HbA1c), blood pressure, and low-density lipoprotein cholesterol (LDL-c)] to prevent the respective complications of these diseases.

An integrated platform approach enables discovery of potent, selective and ligand-competitive cyclic peptides targeting the GIP receptor

In any drug discovery effort, the identification of hits for further optimisation is of crucial importance. For peptide therapeutics, display technologies such as mRNA display have emerged as powerful methodologies to identify these desired de novo hit ligands against targets of interest. The diverse peptide libraries are genetically encoded in these technologies, allowing for next-generation sequencing to be used to efficiently identify the binding ligands. Despite the vast datasets that can be generated, current downstream methodologies, however, are limited by low throughput validation processes, including hit prioritisation, peptide synthesis, biochemical and biophysical assays. In this work we report a highly efficient strategy that combines bioinformatic analysis with state-of-the-art high throughput peptide synthesis to identify nanomolar cyclic peptide (CP) ligands of the human glucose-dependent insulinotropic peptide receptor (hGIP-R). Furthermore, our workflow is able to discriminate between functional and remote binding non-functional ligands. Efficient structure-activity relationship analysis (SAR) combined with advanced in silico structural studies allow deduction of a thorough and holistic binding model which informs further chemical optimisation, including efficient half-life extension. We report the identification and design of the first de novo, GIP-competitive, incretin receptor family-selective CPs, which exhibit an in vivo half-life up to 10.7 h in rats. The workflow should be generally applicable to any selection target, improving and accelerating hit identification, validation, characterisation, and prioritisation for therapeutic development.

Anti-obesity drug discovery: advances and challenges

Enormous progress has been made in the last half-century in the management of diseases closely integrated with excess body weight, such as hypertension, adult-onset diabetes and elevated cholesterol. However, the treatment of obesity itself has proven largely resistant to therapy, with anti-obesity medications (AOMs) often delivering insufficient efficacy and dubious safety. Here, we provide an overview of the history of AOM development, focusing on lessons learned and ongoing obstacles. Recent advances, including increased understanding of the molecular gut-brain communication, are inspiring the pursuit of next-generation AOMs that appear capable of safely achieving sizeable and sustained body weight loss.

Tirzepatide cardiovascular event risk assessment: a pre-specified meta-analysis

Tirzepatide is a novel, once weekly, dual GIP/GLP-1 receptor agonist and is under development for the treatment of type 2 diabetes (T2D) and obesity. Its association with cardiovascular outcomes requires evaluation. This pre-specified cardiovascular meta-analysis included all seven randomized controlled trials with a duration of at least 26 weeks from the tirzepatide T2D clinical development program, SURPASS. The pre-specified primary objective of this meta-analysis was the comparison of the time to first occurrence of confirmed four-component major adverse cardiovascular events (MACE-4; cardiovascular death, myocardial infarction, stroke and hospitalized unstable angina) between pooled tirzepatide groups and control groups. A stratified Cox proportional hazards model, with treatment as a fixed effect and trial-level cardiovascular risk as the stratification factor, was used for the estimation of hazard ratios (HRs) and confidence intervals (CIs) comparing tirzepatide to control. Data from 4,887 participants treated with tirzepatide and 2,328 control participants were analyzed. Overall, 142 participants, 109 from the trial with high cardiovascular risk and 33 from the six trials with lower cardiovascular risk, had at least one MACE-4 event. The HRs comparing tirzepatide versus controls were 0.80 (95% CI, 0.57-1.11) for MACE-4; 0.90 (95% CI, 0.50-1.61) for cardiovascular death; and 0.80 (95% CI, 0.51-1.25) for all-cause death. No evidence of effect modifications was observed for any subgroups, although the evidence was stronger for participants with high cardiovascular risk. Tirzepatide did not increase the risk of major cardiovascular events in participants with T2D versus controls.

Gastrointestinal Incretins-Glucose-Dependent Insulinotropic Polypeptide (GIP) and Glucagon-like Peptide-1 (GLP-1) beyond Pleiotropic Physiological Effects Are Involved in Pathophysiology of Atherosclerosis and Coronary Artery Disease-State of the Art

Simple Summary

The presented manuscript contains the most current and extensive summary of the role of the most predominant gastrointestinal hormones—GIP and GLP-1 in the pathophysiology of atherosclerosis and coronary artery disease both in animals and humans. We have described GIP and GLP-1 as (1) expressed in many human tissues, (2) emphasized relationship between GIP and GLP-1 and inflammation, (3) highlighted importance of GIP and GLP-1-dependent pathways in atherosclerosis and coronary artery disease and (4) proved that GIP and GLP-1 could be used as markers of incidence, clinical course and recurrence of coronary artery disease, and related to extent and severity of atherosclerosis and myocardial ischemia. Our initial review may state a cornerstone for the future, however, there are still many unknowns and understatements on this topic. Due to the widespread growing interest for the potential use of incretins in cardiovascular diseases, we think that further research in this direction is desirable. For the future, we would like to recognize GIP and GLP-1 as widely implemented into clinical practice as new biomarkers of atherosclerosis and coronary artery disease.

Abstract

Coronary artery disease (CAD), which is the manifestation of atherosclerosis in coronary arteries, is the most common single cause of death and is responsible for disabilities of millions of people worldwide. Despite numerous dedicated clinical studies and an enormous effort to develop diagnostic and therapeutic methods, coronary atherosclerosis remains one of the most serious medical problems of the modern world. Hence, new markers are still being sought to identify and manage CAD optimally. Trying to face this problem, we have raised the question of the most predominant gastrointestinal hormones; glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), mainly involved in carbohydrates disorders, could be also used as new markers of incidence, clinical course, and recurrence of CAD and are related to extent and severity of atherosclerosis and myocardial ischemia. We describe GIP and GLP-1 as expressed in many animal and human tissues, known to be connected to inflammation and related to enormous noncardiac and cardiovascular (CV) diseases. In animals, GIP and GLP-1 improve endothelial function and lead to reduced atherosclerotic plaque macrophage infiltration and stabilize atherosclerotic lesions by directly blocking monocyte migration. Moreover, in humans, GIPR activation induces the pro-atherosclerotic factors ET-1 (endothelin-1) and OPN (osteopontin) but also has anti-atherosclerotic effects through secretion of NO (nitric oxide). Furthermore, four large clinical trials showed a significant reduction in composite of CV death, MI, and stroke in long-term follow-up using GLP-1 analogs for DM 2 patients: liraglutide in LEADER, semaglutide in SUSTAIN-6, dulaglutide in REWIND and albiglutide in HARMONY. However, very little is known about GIP metabolism in the acute phase of myocardial ischemia or for stable patients with CAD, which constitutes a direction for future research. This review aims to comprehensively discuss the impact of GIP and GLP-1 on atherosclerosis and CAD and its potential therapeutic implications.

Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes: The SURPASS-5 Randomized Clinical Trial

IMPORTANCE

The effects of tirzepatide, a dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, as an addition to insulin glargine for treatment of type 2 diabetes have not been described.

OBJECTIVE

To assess the efficacy and safety of tirzepatide added to insulin glargine in patients with type 2 diabetes with inadequate glycemic control.

DESIGN, SETTING, AND PARTICIPANTS

Randomized phase 3 clinical trial conducted at 45 medical research centers and hospitals in 8 countries (enrollment from August 30, 2019, to March 20, 2020; follow-up completed January 13, 2021) in 475 adults with type 2 diabetes and inadequate glycemic control while treated with once-daily insulin glargine with or without metformin.

INTERVENTIONS

Patients were randomized in a 1:1:1:1 ratio to receive once-weekly subcutaneous injections of 5-mg (n = 116), 10-mg (n = 119), or 15-mg (n = 120) tirzepatide or volume-matched placebo (n = 120) over 40 weeks. Tirzepatide was initiated at 2.5 mg/week and escalated by 2.5 mg every 4 weeks until the assigned dose was achieved.

MAIN OUTCOMES AND MEASURES

The primary end point was mean change from baseline in glycated hemoglobin A1c (HbA1c) at week 40. The 5 key secondary end points included mean change in body weight and percentage of patients achieving prespecified HbA1c levels.

RESULTS

Among 475 randomized participants (211 [44%] women; mean [SD] age, 60.6 [9.9] years; mean [SD] HbA1c, 8.31% [0.85%]), 451 (94.9%) completed the trial. Treatment was prematurely discontinued by 10% of participants in the 5-mg tirzepatide group, 12% in the 10-mg tirzepatide group, 18% in the 15-mg tirzepatide group, and 3% in the placebo group. At week 40, mean HbA1c change from baseline was -2.40% with 10-mg tirzepatide and -2.34% with 15-mg tirzepatide vs -0.86% with placebo (10 mg: difference vs placebo, -1.53% [97.5% CI, -1.80% to -1.27%]; 15 mg: difference vs placebo, -1.47% [97.5% CI, -1.75% to -1.20%]; P < .001 for both). Mean HbA1c change from baseline was -2.11% with 5-mg tirzepatide (difference vs placebo, -1.24% [95% CI, -1.48% to -1.01%]; P < .001]). Mean body weight change from baseline was -5.4 kg with 5-mg tirzepatide, -7.5 kg with 10-mg tirzepatide, -8.8 kg with 15-mg tirzepatide and 1.6 kg with placebo (5 mg: difference, -7.1 kg [95% CI, -8.7 to -5.4]; 10 mg: difference, -9.1 kg [95% CI, -10.7 to -7.5]; 15 mg: difference, -10.5 kg [95% CI, -12.1 to -8.8]; P < .001 for all). Higher percentages of patients treated with tirzepatide vs those treated with placebo had HbA1c less than 7% (85%-90% vs 34%; P < .001 for all). The most common treatment-emergent adverse events in the tirzepatide groups vs placebo group were diarrhea (12%-21% vs 10%) and nausea (13%-18% vs 3%).

CONCLUSIONS AND RELEVANCE

Among patients with type 2 diabetes and inadequate glycemic control despite treatment with insulin glargine, the addition of subcutaneous tirzepatide, compared with placebo, to titrated insulin glargine resulted in statistically significant improvements in glycemic control after 40 weeks.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04039503.

State-of-the-Art Overview of the Pharmacological Treatment of Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, and non-alcoholic steatohepatitis (NASH), a subtype of NAFLD, can progress to cirrhosis, hepatocellular carcinoma, and death. Nevertheless, the current treatment for NAFLD/NASH is limited to lifestyle modifications, and no drugs are currently officially approved as treatments for NASH. Many global pharmaceutical companies are pursuing the development of medications for the treatment of NASH, and results from phase 2 and 3 clinical trials have been published in recent years. Here, we review data from these recent clinical trials and reports on the efficacy of newly developed antidiabetic drugs in NASH treatment.

Obesity management as a primary treatment goal for type 2 diabetes: time to reframe the conversation

Obesity is now recognised as a disease that is associated with serious morbidity and increased mortality. One of its main metabolic complications is type 2 diabetes, as the two conditions share key pathophysiological mechanisms. Weight loss is known to reverse the underlying metabolic abnormalities of type 2 diabetes and, as such, improve glucose control; loss of 15% or more of bodyweight can have a disease-modifying effect in people with type 2 diabetes, an outcome that is not attainable by any other glucose-lowering intervention. Furthermore, weight loss in this population exerts benefits that extend beyond glycaemic control to improve risk factors for cardiometabolic disease and quality of life. We review the evidence supporting the role of weight loss in the management of type 2 diabetes and propose that many patients with type 2 diabetes would benefit from having a primary weight-centric approach to diabetes treatment. We discuss the logistical challenges to implementing a new weight-centric primary treatment goal in people with type 2 diabetes.

Glucose-dependent insulinotropic polypeptide and tissue inflammation: Implications for atherogenic cardiovascular disease

Glucose-dependent insulinotropic polypeptide (GIP) has pleiotropic actions on pancreatic endocrine function, adipose tissue lipid metabolism, and skeletal calcium metabolism. Recent data indicate a potential new role for GIP in the pathogenesis of cardiovascular disease. This review focuses on the emerging literature that highlights GIP’s role in inflammation—an established process in the initiation and progression of atherosclerosis. In vasculature tissue, GIP may reduce concentrations of circulating inflammatory cytokines, attenuate vascular endothelial inflammation, and directly limit atherosclerotic vascular damage. Important to recognize is that evidence exists to support both pro- and anti-inflammatory effects of GIP even within the same tissue/cell type. Therefore, future study designs must account for factors such as model heterogeneity, physiological relevance of doses/exposures, potential indirect effects on inflammatory pathways, and the glucose-dependent insulinotropic polypeptide receptor (GIPR) agonist form. Elucidating the specific effects of enhanced GIP signaling in vascular inflammation and atherosclerosis is crucial given the existing widespread use of DPP4 inhibitors and the emergence of dual-incretin receptor agonists for type 2 diabetes treatment.

Effects on weight loss and glycemic control with SAR441255, a potent unimolecular peptide GLP-1/GIP/GCG receptor triagonist

Unimolecular triple incretins, combining the activity of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG), have demonstrated reduction in body weight and improved glucose control in rodent models. We developed SAR441255, a synthetic peptide agonist of the GLP-1, GCG, and GIP receptors, structurally based on the exendin-4 sequence. SAR441255 displays high potency with balanced activation of all three target receptors. In animal models, metabolic outcomes were superior to results with a dual GLP-1/GCG receptor agonist. Preclinical in vivo positron emission tomography imaging demonstrated SAR441255 binding to GLP-1 and GCG receptors. In healthy subjects, SAR441255 improved glycemic control during a mixed-meal tolerance test and impacted biomarkers for GCG and GIP receptor activation. Single doses of SAR441255 were well tolerated. The results demonstrate that integrating GIP activity into dual GLP-1 and GCG receptor agonism provides improved effects on weight loss and glycemic control while buffering the diabetogenic risk of chronic GCG receptor agonism.

Tirzepatide: A Novel, Once-weekly Dual GIP and GLP-1 Receptor Agonist for the Treatment of Type 2 Diabetes

Gastrointestinal hormones are currently used to treat type 2 diabetes mellitus (T2D). Incretin preparations with gastric inhibitory polypeptide (GIP) activity or glucagon-like peptide-1 (GLP-1) provide new means for controlling blood glucose levels, body weight, and lipid metabolism. GIP, an incretin, has not been used due to lack of promising action against diabetes. However, recent studies have shown that GIP has an important effect on glucagon and insulin secretion under normoglycaemic conditions. Co-existence of GIP with GLP-1 and glucagon signalling leads to a stronger effect than that of GLP-1 stimulation alone. The development of a GIP/GLP-1R unimolecular dual agonist with affinity for both GIP and GLP-1 receptors is under investigation, and the drug is expected to be clinically available in the near future. Tirzepatide, a GIP/GLP-1R unimolecular dual agonist, regulates metabolism via both peripheral organs and the central nervous system. The SURPASS phase III clinical trials conducted for tirzepatide comprise 10 clinical trials, including five global trials and the global SURPASS-CVOT trial, with >13,000 patients with T2D (ClinicalTrials.gov Identifier: NCT04255433). The clinical application of tirzepatide as a therapy for T2D may provide new insights into diabetic conditions and help clarify the role of GIP in its pathogenesis.

Obesity-related kidney disease: Beyond hypertension and insulin-resistance

Chronic kidney disease (CKD) causes considerable morbidity, mortality, and health expenditures worldwide. Obesity is a significant risk factor for CKD development, partially explained by the high prevalence of diabetes mellitus and hypertension in obese patients. However, adipocytes also possess potent endocrine functions, secreting a myriad of cytokines and adipokines that contribute to insulin resistance and induce a chronic low-grade inflammatory state thereby damaging the kidney. CKD development itself is associated with various metabolic alterations that exacerbate adipose tissue dysfunction and insulin resistance. This adipose-renal axis is a major focus of current research, given the rising incidence of CKD and obesity. Cellular senescence is a biologic hallmark of aging, and age is another significant risk factor for obesity and CKD. An elevated senescent cell burden in adipose tissue predicts renal dysfunction in animal models, and senotherapies may alleviate these phenotypes. In this review, we discuss the direct mechanisms by which adipose tissue contributes to CKD development, emphasizing the potential clinical importance of such pathways in augmenting the care of CKD.

Pharmacologic management of weight regain following bariatric surgery

While bariatric surgery restults in significant long-term weight loss for most patients with obesity, post-surgical weight gain affects a considerable percentage of patients to varying degrees of severity. Furthermore, a small but significant percentage of patients experience inadequate post-surgical weight loss. Although many studies have examined the role of anti-obesity medications to address post-operative weight regain, an evidence-based consensus has not yet been achieved because of the heterogeneity of populations studied and the studies themselves. Observational studies in the post-bariatric surgery population consistently demonstrate the benefit of medical weight management after bariatric surgery, with most evidence highlighting liraglutide, topiramate, and phentermine/topiramate. New anti-obesity medications are anticipated to be helpful for post-surgical weight optimization given their efficacy in the non-surgical population.

Glucagon-Like Peptide-1 Receptor Agonists and Dual Glucose-Dependent Insulinotropic Polypeptide/Glucagon-Like Peptide-1 Receptor Agonists in the Treatment of Obesity/Metabolic Syndrome, Prediabetes/Diabetes and Non-Alcoholic Fatty Liver Disease-Current Evidence

The obesity pandemic is accompanied by increased risk of developing metabolic syndrome (MetS) and related conditions: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH), type 2 diabetes mellitus (T2DM) and cardiovascular (CV) disease (CVD). Lifestyle, as well as an imbalance of energy intake/expenditure, genetic predisposition, and epigenetics could lead to a dysmetabolic milieu, which is the cornerstone for the development of cardiometabolic complications. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RAs promote positive effects on most components of the "cardiometabolic continuum" and consequently help reduce the need for polypharmacy. In this review, we highlight the main pathophysiological mechanisms and risk factors (RFs), that could be controlled by GLP-1 and dual GIP/GLP-1 RAs independently or through synergism or differences in their mode of action. We also address the evidence on the use of GLP-1 and dual GIP/GLP-1 RAs in the treatment of obesity, MetS and its related conditions (prediabetes, T2DM and NAFLD/NASH). In conclusion, GLP-1 RAs have already been established for the treatment of T2DM, obesity and cardioprotection in T2DM patients, while dual GIP/GLP-1 RAs appear to have the potential to possibly surpass them for the same indications. However, their use in the prevention of T2DM and the treatment of complex cardiometabolic metabolic diseases, such as NAFLD/NASH or other metabolic disorders, would benefit from more evidence and a thorough clinical patient-centered approach. There is a need to identify those patients in whom the metabolic component predominates, and whether the benefits outweigh any potential harm.

The potential of GLP-1 receptor agonists in type 2 diabetes and chronic kidney disease: from randomised trials to clinical practice

Chronic kidney disease (CKD) affects around 10% of the global population and is most often caused by diabetes. Diabetes with CKD (diabetic kidney disease, DKD) is a progressive condition that may cause kidney failure and which contributes significantly to the excess morbidity and mortality in these patients. DKD is treated with direct disease-targeting therapies like blockers of the renin-angiotensin system, sodium-glucose cotransporter-2 (SGLT-2) inhibitors and non-steroidal mineralocorticoid receptor antagonists as well as indirect therapies impacting hyperglycaemia, dyslipidaemia, obesity and hypertension, which all together reduce disease progression. While no glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are currently indicated to improve kidney outcomes, accumulating evidence from cardiovascular outcomes trials (CVOTs) corroborates a kidney-protective effect in people with T2D and CKD, and GLP-1 RAs are now mentioned in international treatment guidelines for type 2 diabetes (T2D) with CKD. GLP-1 RAs are indicated to improve glycaemia in people with T2D; certain GLP-1 RAs are also approved for weight management and to reduce cardiovascular risk in T2D. Ongoing pivotal trials are assessing additional indications, including T2D with CKD. In this article, we review and discuss kidney outcomes from a multitude of completed clinical trials as well as real-world evidence and ongoing clinical trials.

Recent Advances in Incretin-Based Pharmacotherapies for the Treatment of Obesity and Diabetes

The incretin hormone glucagon-like peptide-1 (GLP-1) has received enormous attention during the past three decades as a therapeutic target for the treatment of obesity and type 2 diabetes. Continuous improvement of the pharmacokinetic profile of GLP-1R agonists, starting from native hormone with a half-life of ~2-3 min to the development of twice daily, daily and even once-weekly drugs highlight the pharmaceutical evolution of GLP-1-based medicines. In contrast to GLP-1, the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) received little attention as a pharmacological target, because of conflicting observations that argue activation or inhibition of the GIP receptor (GIPR) provides beneficial effects on systemic metabolism. Interest in GIPR agonism for the treatment of obesity and diabetes was recently propelled by the clinical success of unimolecular dual-agonists targeting the receptors for GIP and GLP-1, with reported significantly improved body weight and glucose control in patients with obesity and type II diabetes. Here we review the biology and pharmacology of GLP-1 and GIP and discuss recent advances in incretin-based pharmacotherapies.

The current significance and prospects for the use of dual receptor agonism GLP-1/Glucagon

The therapeutic arsenal for treating type 2 diabetes mellitus (T2DM) has been enriched recently with the inclusion of type 1 glucagon-like peptide (GLP-1). GLP-1 receptor agonists (RA) secondarily reduce appetite, decrease gastric emptying, and reduce body weight. This effect has been used to treat overweight/obesity, especially with comorbidities associated with T2DM. However, the first formulations and adverse effects gradually gave way to new formulations with fewer unpleasant effects and a more extended period of action (weekly subcutaneous administration and even oral administration), which improved the acceptance and adherence to the treatment. Therefore, titration of GLP-1RA should be done gradually. Furthermore, when side effects are consistent and intolerable after weeks/months of titration, a lower dose or a combination of antidiabetic therapies should be implemented, avoiding treatment interruption. The effort to produce increasingly powerful molecules with fewer side effects is the driving force behind the pharmaceutical industry. The unimolecular dual agonism GLP-1RA plus glucagon receptor agonism (GRA) represents an updated pharmacological indication for controlling blood glucose levels in treating T2DM and its comorbidities, showing better effects with less adverse impact than mono GLP-1RA. There are currently different proposals in this way by different laboratories. Nevertheless, the experimental results are promising and show that soon, we will have the contribution of new drugs for the treatment of T2DM.

The Benefits of Safely Achieving Near Normoglycemia from the Perspective of People with Type 2 Diabetes: A Quantitative Survey Study

PURPOSE

To understand the perspectives of people with type 2 diabetes (T2D) on safely reaching near normoglycemia, defined as a glycated hemoglobin A1c (HbA1c) value of <6%. HbA1c indicates the average blood sugar level over the past few months.

PATIENTS AND METHODS

This cross-sectional online quantitative survey of people with T2D asked about the current impacts of T2D, the anticipated benefits of safely achieving near normoglycemia among participants with a current HbA1c ≥6%, or the actual benefits of safely achieving near normoglycemia among participants who had an HbA1c <6%. Participants reported on specific areas of psychological/emotional impact of T2D and the psychological/emotional benefits of achieving near normoglycemia.

RESULTS

Participants (N = 1000; United States = 500 and United Kingdom = 500) were 53.1% male and had a mean age of 62.9 years (SD = 13.3). The majority reported that the current HbA1c ≥6% (81.2%) and 49.2% had been diagnosed more than 10 years ago. The vast majority of participants (>90%) indicated that achieving near normoglycemia was meaningful, with 95% of the participants indicating that achieving near normoglycemia would be of somewhat or extreme importance to them. In total, 93.8% of participants with a current HbA1c ≥6% and 80.3% of those with a current HbA1c <6% anticipated/reported having experienced improvements as a result of achieving near normoglycemia. Among those who experienced or anticipated positive psychological/emotional impacts (n = 247), the most commonly reported impacts included less worry about future diabetes-related complications (79.8%), feeling in control over one's life (72.9%), and overall health-related quality of life (59.9%).

CONCLUSION

Achieving near normoglycemia is both meaningful and important to the majority of people with T2D, including both those who have and those who have not experienced reaching near normoglycemia. A wide range of specific impacts, including psychological/emotional concepts, are experienced by people with T2D, many of which may be improved through achieving near normoglycemia.

The Emerging Role of Glucagon-like Peptide-1 Receptor Agonists for the Management of NAFLD

CONTEXT

The burden of cirrhosis from nonalcoholic fatty liver disease (NAFLD) is reaching epidemic proportions in the United States. This calls for greater awareness among endocrinologists, who often see but may miss the diagnosis in adults with obesity or type 2 diabetes mellitus (T2D) who are at the highest risk. At the same time, recent studies suggest that glucagon-like peptide-1 receptor agonists (GLP-1RAs) are beneficial vs nonalcoholic steatohepatitis (NASH) in this population. This minireview aims to assist endocrinologists to recognize the condition and recent work on the role of GLP-1RAs in NAFLD/NASH.

EVIDENCE ACQUISITION

Evidence from observational studies, randomized controlled trials, and meta-analyses.

EVIDENCE SYNTHESIS

Endocrinologists should lead multidisciplinary teams to implement recent consensus statements on NAFLD that call for screening and treatment of clinically significant fibrosis to prevent cirrhosis, especially in the high-risk groups (ie, people with obesity, prediabetes, or T2D). With no US Food and Drug Administration (FDA)-approved agents, weight loss is central to successful management, with pharmacological treatment options limited today to vitamin E (in people without T2D) and diabetes medications that reverse steatohepatitis, such as pioglitazone or GLP-1RA. Recently, the benefit of GLP-1RAs in NAFLD, suggested from earlier trials, has been confirmed in adults with biopsy-proven NASH. In 2021, the FDA also approved semaglutide for obesity management.

CONCLUSION

A paradigm change is developing between the endocrinologist's greater awareness about their critical role to curve the epidemic of NAFLD and new clinical care pathways that include a broader use of GLP-1RAs in the management of these complex patients.

Basal insulin intensification with GLP-1RA and dual GIP and GLP-1RA in patients with uncontrolled type 2 diabetes mellitus: A rapid review of randomized controlled trials and meta-analysis

Tirzepatide, a dual agonist of Glucose-Dependent Insulinotropic Polypeptide (GIP) and Glucagon-Like Peptide 1 (GLP-1) receptors, improved glucose control and reduced body weight in different therapeutic approaches. Herein, we overviewed the role of GIP and GLP-1 in the pathophysiology of type 2 diabetes and systematically reviewed the efficacy and safety of injectable incretin-based therapy added to basal insulin in light of the results of the SURPASS-5 trial. We identified eleven randomized clinical trials. GLP-1 receptor agonists (GLP-1RAs) or Tirzepatide added to basal insulin than rigorously titrated basal insulin significantly ameliorates glucose control (Δ HbA_1c = -1%, 95% CI -1.25; -0.74, I² 94%; Δ FPG = -14.6 mg/dL, 95% CI -21.6-; -7.6, I² 90%; chance to achieve HbA_{1c <}7% = RR 2.62, 95% CI 2.10; 3.26, I² 89%), reduces body weight (Δ = -3.95 kg, 95% CI -5.1, -2.79, I² 96%) without increasing the risk of hypoglycemia (RR = 1.01, 95% CI 0.86; 1.18, I² 7.7%). Tirzepatide provides an impressive weight loss exceeding that observed with GLP-1RAs. Injectable incretin-based therapy plus basal insulin remains a potent and safe therapeutic approach in uncontrolled type 2 diabetes patients previously treated with basal insulin alone. Tirzepatide is expected to ameliorate the management of "diabesity" in this usually difficult-to-treat cluster of patients.

Novel Drugs for Diabetes Therapy

Since the first use of insulin 100 years ago, there have been marked improvements in diabetes therapy including, but not limited to, the development of oral antidiabetic agents (OADs), incretin mimetics and insulin analogues. Still, there are substantial shortcomings in diabetes therapy: the blood-glucose lowering effect of OADs is often limited, incretin mimetics often induce gastrointestinal side effects and insulins still induce hypoglycaemia and weight gain in many patients.This review evaluates on-going developments of antidiabetic drugs for their potential for future therapy focussing on injectable therapies. Recent data from dual agonists, in particular tirzepatide, a combination of GIP- and GLP-1 receptor agonists, show unprecedented reductions in HbA1c, body weight and cardiovascular risk factors. Once-weekly administrations of incretin mimetics open up the potential of a combination with once-weekly insulins that have been shown to have low peak-to-trough fluctuations. Eventually, it might be feasible to administer incretins and insulins (combinations) orally. While this has already been achieved for incretins, there are still some challenges for the oral application of insulin. Nevertheless, many promising data of novel antidiabetic drugs clearly indicate that therapy of people with diabetes will become easier, safer and more efficacious in the next years.

Dual-agonist incretin peptides from fish with potential for obesity-related Type 2 diabetes therapy - A review

The long-acting glucagon-like peptide-1 receptor (GLP1R) agonist, semaglutide and the unimolecular glucose-dependent insulinotropic polypeptide receptor (GIPR)/GLP1R dual-agonist, tirzepatide have been successfully introduced as therapeutic options for patients with Type-2 diabetes (T2DM) and obesity. Proglucagon-derived peptides from phylogenetically ancient fish act as naturally occurring dual agonists at the GLP1R and the glucagon receptor (GCGR) with lamprey GLP-1 and paddlefish glucagon being the most potent and effective in stimulating insulin release from BRIN-BD11 clonal β-cells. These peptides were also the most effective in lowering blood glucose and elevating plasma insulin concentrations when administered intraperitoneally to overnight-fasted mice together with a glucose load. Zebrafish GIP acts as a dual agonist at the GIPR and GLP1R receptors. Studies with the high fat-fed mouse, an animal model with obesity, impaired glucose-tolerance and insulin-resistance, have shown that twice-daily administration of the long-acting analogs [D-Ala²]palmitoyl-lamprey GLP-1 and [D-Ser²]palmitoyl-paddlefish glucagon over 21 days improves glucose tolerance and insulin sensitivity. This was associated with β-cell proliferation, protection of β-cells against apoptosis, decreased pancreatic glucagon content, improved lipid profile, reduced food intake and selective alteration in the expression of genes involved in β-cell stimulus-secretion coupling. In insulin-deficient Glu^CreERT2;ROSA26-eYFP transgenic mice, the peptides promoted an increase in β-cell mass with positive effects on transdifferentiation of glucagon-producing to insulin-producing cells. Naturally occurring fish dual agonist peptides, particularly lamprey GLP-1 and paddlefish glucagon, provide templates for development into therapeutic agents for obesity-related T2DM.

Clinical perspectives on the use of the GIP/GLP-1 receptor agonist tirzepatide for the treatment of type-2 diabetes and obesity

Incretin-based therapies with glucagon-like peptide-1 receptor agonists (GLP-1RA) are already established in the treatment of type 2 diabetes (T2D). The development of novel dual- or triple-receptor agonists that bind to the receptors not only for GLP-1 but also to the receptors for glucose-dependent insulinotropic polypeptide (GIP) and/or glucagon is intended to address different metabolic pathways for carbohydrate, lipid, and protein metabolism simultaneously. Dual- and triple-receptor agonists acting via different receptors and postreceptor pathways seem attractive in view of potentially additive or synergistic effects in the treatment of T2D and obesity. Recently, the first approval for a dual-receptor agonist marks an important step in this development. The GIP/GLP-1-receptor agonist tirzepatide was approved for the treatment of T2D by the Food and Drug Administration (FDA) in the USA for once-weekly subcutaneous injections in May 2022 and has just received a positive opinion from the European Medicines Agency (EMA). Tirzepatide dose-dependently leads to clinically significant reductions in glycemic parameters and body weight and has been shown to have stronger effects in reducing these parameters than standard antidiabetic therapy. This article summarizes the current clinical study program and the respective outcomes and highlights further potential indications for tirzepatide in the treatment of obesity and potentially other comorbidities of T2D.

Glucagon-like Peptide-1 Receptor Analogues for the Treatment of Obesity

There is an increasing prevalence of obesity worldwide, associated with significant morbidity and mortality, which frequently reduces quality of life and life expectancy. Consequently, there is a substantial and growing personal and economic burden necessitating the development of more effective therapies for obesity. Glucagon-like peptide-1 receptor analogues (GLP-1RAs) are licensed for the treatment of type 2 diabetes (T2D), and there is substantial evidence that these drugs not only improve cardiovascular outcomes but also promote weight loss. More recent evidence supports the use of the GLP-1RAs liraglutide and semaglutide in people with obesity without T2D. This article discusses the results of the major cardiovascular outcome trials for GLP-1RAs in people with T2D, the SCALE Obesity and Prediabetes study (Effect of liraglutide on body weight in non-diabetic obese subjects or overweight subjects with co-morbidities: SCALE™ - Obesity and Pre-diabetes; ClinicalTrials.gov identifier: NCT01272219; investigating liraglutide) and the STEP studies (Semaglutide treatment effect in people with obesity; assorted studies; investigating subcutaneous semaglutide). We also highlight the importance of a cost-effective approach to obesity pharmacotherapy. Clinicians should consider the use of GLP-1RAs in people with obesity, especially those with T2D or other obesity-related diseases, such as hypertension and dyslipidaemia. Ongoing trials, as well as clinical and cost-effectiveness appraisals, are anticipated over the next 12 months, and their findings may change the current landscape of obesity pharmacotherapy.

Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes Mellitus and Cardiovascular Disease: The Past, Present, and Future

Type 2 diabetes mellitus (T2DM) is associated with high cardiovascular morbidity and mortality, and cardiovascular diseases are the leading causes of death and disability in people with T2DM. Unfortunately, therapies strictly aimed at glycemic control have poorly contributed to a significant reduction in the risk of cardiovascular events. On the other hand, randomized controlled trials have shown that five glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and one exendin-based GLP-1 RA reduced atherosclerotic cardiovascular events in patients with diabetes at high cardiovascular risk. Furthermore, a meta-analysis including these six agents showed a reduction in major adverse cardiovascular events as well as all-cause mortality compared with placebo, regardless of structural homology. Evidence has also shown that some drugs in this class have beneficial effects on renal outcomes, such as preventing the onset of macroalbuminuria. In addition to lowering blood pressure, these drugs also favorably impacted on body weight in large randomized controlled trials as in real-world studies, a result considered a priority in T2DM management; these and other factors may justify the benefits of GLP-1 RAs upon the cardiovascular system, regardless of glycemic control. Finally, studies showed safety with a low risk of hypoglycemia and no increase in pancreatitis events. Given these benefits, GLP-1 RAs were preferentially endorsed in the guidelines of the European and American societies for patients with these conditions. This narrative review provides a current and comprehensive overview of GLP-1 RAs as cardiovascular and renal protective agents, far beyond their use as glucose-lowering drugs, supporting their effectiveness in treating patients with T2DM at high cardiovascular risk.

Role of a Dual Glucose-Dependent Insulinotropic Peptide (GIP)/Glucagon-like Peptide-1 Receptor Agonist (Twincretin) in Glycemic Control: From Pathophysiology to Treatment

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two gut hormones, defined incretins, responsible for the amplification of insulin secretion after oral glucose intake. Unlike GLP-1, GIP has little acute effect on insulin secretion and no effect on food intake; instead it seems that the GIP may be an obesity-promoting hormone. In patients with type2 diabetes mellitus (T2DM) some studies found a downregulation of GIP receptors on pancreatic β cells caused by hyperglycemic state, but the glucagonotropic effect persisted. Agonists of the receptor for the GLP-1 have proven successful for the treatment of diabetes, since they reduce the risk for cardiovascular and renal events, but the possible application of GIP as therapy for T2DM is discussed. Moreover, the latest evidence showed a synergetic effect when GIP was combined with GLP-1 in monomolecular co-agonists. In fact, compared with the separate infusion of each hormone, the combination increased both insulin response and glucagonostatic response. In accordance with theseconsiderations, a dual GIP/GLP-1receptor agonist, i.e., Tirzepatide, known as a "twincretin" had been developed. In the pre-clinical trials, as well as Phase 1-3 clinical trials, Tirzepatideshowedpotent glucose lowering and weight loss effects within an acceptable safety.

Leveraging human genetic data to investigate the cardiometabolic effects of glucose-dependent insulinotropic polypeptide signalling

AIMS/HYPOTHESIS

The aim of this study was to leverage human genetic data to investigate the cardiometabolic effects of glucose-dependent insulinotropic polypeptide (GIP) signalling.

METHODS

Data were obtained from summary statistics of large-scale genome-wide association studies. We examined whether genetic associations for type 2 diabetes liability in the GIP and GIPR genes co-localised with genetic associations for 11 cardiometabolic outcomes. For those outcomes that showed evidence of co-localisation (posterior probability >0.8), we performed Mendelian randomisation analyses to estimate the association of genetically proxied GIP signalling with risk of cardiometabolic outcomes, and to test whether this exceeded the estimate observed when considering type 2 diabetes liability variants from other regions of the genome.

RESULTS

Evidence of co-localisation with genetic associations of type 2 diabetes liability at both the GIP and GIPR genes was observed for five outcomes. Mendelian randomisation analyses provided evidence for associations of lower genetically proxied type 2 diabetes liability at the GIP and GIPR genes with lower BMI (estimate in SD units -0.16, 95% CI -0.30, -0.02), C-reactive protein (-0.13, 95% CI -0.19, -0.08) and triacylglycerol levels (-0.17, 95% CI -0.22, -0.12), and higher HDL-cholesterol levels (0.19, 95% CI 0.14, 0.25). For all of these outcomes, the estimates were greater in magnitude than those observed when considering type 2 diabetes liability variants from other regions of the genome.

CONCLUSIONS/INTERPRETATION

This study provides genetic evidence to support a beneficial role of sustained GIP signalling on cardiometabolic health greater than that expected from improved glycaemic control alone. Further clinical investigation is warranted.

DATA AVAILABILITY

All data used in this study are publicly available. The scripts for the analysis are available at: https://github.com/vkarhune/GeneticallyProxiedGIP .

Amplifying the antidiabetic actions of glucagon-like peptide-1: Potential benefits of new adjunct therapies

Clinically approved for the treatment of diabetes and obesity, glucagon-like peptide-1 (GLP-1) receptor agonists display prominent glucose- and weight-lowering effects as well as positive cardioprotective and neuroprotective actions. Despite these benefits, bariatric surgery remains superior in producing robust and sustained weight loss alongside improvements in metabolic control with possible diabetes remission. The current review considers the potential for adjunct therapies to augment the therapeutic actions of GLP-1 receptor agonists. In this regard, several gut-derived hormones also, modulated by bariatric surgery, display additive properties when combined with GLP-1 receptor agonists in both preclinical and clinical studies. In addition, glucocorticoids and oestrogen have shown promise in augmenting the biological actions of GLP-1 in animal models. Additionally, GLP-1 efficacy can also be enhanced by use of compounds that prolong GLP-1 receptor coupling to potentiate downstream receptor signalling. Taken together, therapies that activate GLP-1 receptor signalling, in combination with various other cell signalling pathways, show potential for treating type 2 diabetes and obesity with superiority over GLP-1 receptor agonist therapy alone.

The dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide: a novel cardiometabolic therapeutic prospect

Incretin hormones are peptides released in the intestine in response to the presence of nutrients in its lumen. The main incretins are glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). GLP-1 stimulates insulin secretion, inhibits glucagon secretion at pancreatic α cells and has also extrapancreatic influences as slowing of gastric emptying which increases the feeling of satiety. GIP is the main incretin hormone in healthy people, causative of most the incretin effects, but the insulin response after GIP secretion in type 2 diabetes mellitus (T2DM) is strongly reduced. Therefore, in the past GIP has been considered an unappealing therapeutic target for T2DM. This conception has been changing during recent years, since it has been reported that resistance to GIP can be reversed and its effectiveness restored by improving glycemic control. This fact paved the way for the development of a GIP receptor agonist-based therapy for T2DM, looking also for the possibility of finding a combined GLP-1/GIP receptor agonist. In this framework, the novel dual GIP and GLP-1 receptor agonist tirzepatide seems to be not just a new antidiabetic medication. Administered as a subcutaneous weekly injection, it is a manifold single pharmacological agent that has the ability to significantly lower glucose levels, as well as improve insulin sensitivity, reduce weight and amend dyslipidemia favorably modifying the lipid profile. Tirzepatide and additional dual GLP-1/GIP receptor agonists that could eventually be developed in the future seem to be a promising furthest advance for the management of several cardiometabolic settings. Obviously, it is too early to be overly hopeful since it is still necessary to determine the long-term effects of these compounds and properly verify the potential cardiovascular benefits. Anyway, we are currently facing a novel and very appealing therapeutic option.

Is Obesity/Adiposity-Based Chronic Disease Curable: The Set Point Theory, the Environment, and Second Generation Medications

Adiposity-Based Chronic Disease (ABCD) is a chronic disease and requires life-long treatment and follow-up. Obesity protects obesity through altered regulation of caloric intake and set point mechanisms that maintains a high equilibrium body weight. Lifestyle interventions and obesity medications do not permanently alter the set point which often makes weight loss achieved by lifestyle short-lived and operates to drive weight regain once medications are discontinued. Bariatric surgery procedures can alter appetite and lower the "set point" for equilibrium body weight via unknown mechanisms. However, few patients attain ideal body weight following surgery, many regain weight, and all require long-term follow-up for the disease. The excess adiposity of ABCD gives rise to complications that impair health and confer morbidity and mortality; however, the genetic risks and potential interactions between genes and environment that give rise to complications also cannot be eliminated. The equilibrium body weight around which set point mechanisms operate can be modified by environment, which underscores the importance of a less obesogenic environment for prevention and treatment of ABCD on a population basis. If ABCD will eventually be curable, this will depend on a clear understanding of the molecular mechanisms that determine the set point regulation of body weight, and an ability to permanently modulate the set point to oscillate around and a lean body mass. The conceptualization of ABCD as a chronic disease, however, does present us with opportunities for primary, secondary, and tertiary prevention to avert disease progression. For tertiary care, the advent of new, more effective, second-generation obesity medications will allow clinicians to treat-to-target via active management of body weight into a target range that will ameliorate specific complications.

Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4): a randomised, open-label, parallel-group, multicentre, phase 3 trial

BACKGROUND

We aimed to assess efficacy and safety, with a special focus on cardiovascular safety, of the novel dual GIP and GLP-1 receptor agonist tirzepatide versus insulin glargine in adults with type 2 diabetes and high cardiovascular risk inadequately controlled on oral glucose-lowering medications.

METHODS

This open-label, parallel-group, phase 3 study was done in 187 sites in 14 countries on five continents. Eligible participants, aged 18 years or older, had type 2 diabetes treated with any combination of metformin, sulfonylurea, or sodium-glucose co-transporter-2 inhibitor, a baseline glycated haemoglobin (HbA_1c) of 7·5-10·5% (58-91 mmol/mol), body-mass index of 25 kg/m² or greater, and established cardiovascular disease or a high risk of cardiovascular events. Participants were randomly assigned (1:1:1:3) via an interactive web-response system to subcutaneous injection of either once-per-week tirzepatide (5 mg, 10 mg, or 15 mg) or glargine (100 U/mL), titrated to reach fasting blood glucose of less than 100 mg/dL. The primary endpoint was non-inferiority (0·3% non-inferiority boundary) of tirzepatide 10 mg or 15 mg, or both, versus glargine in HbA_1c change from baseline to 52 weeks. All participants were treated for at least 52 weeks, with treatment continued for a maximum of 104 weeks or until study completion to collect and adjudicate major adverse cardiovascular events (MACE). Safety measures were assessed over the full study period. This study was registered with ClinicalTrials.gov, NCT03730662.

FINDINGS

Patients were recruited between Nov 20, 2018, and Dec 30, 2019. 3045 participants were screened, with 2002 participants randomly assigned to tirzepatide or glargine. 1995 received at least one dose of tirzepatide 5 mg (n=329, 17%), 10 mg (n=328, 16%), or 15 mg (n=338, 17%), or glargine (n=1000, 50%), and were included in the modified intention-to-treat population. At 52 weeks, mean HbA_1c changes with tirzepatide were -2·43% (SD 0·05) with 10 mg and -2·58% (0·05) with 15 mg, versus -1·44% (0·03) with glargine. The estimated treatment difference versus glargine was -0·99% (multiplicity adjusted 97·5% CI -1·13 to -0·86) for tirzepatide 10 mg and -1·14% (-1·28 to -1·00) for 15 mg, and the non-inferiority margin of 0·3% was met for both doses. Nausea (12-23%), diarrhoea (13-22%), decreased appetite (9-11%), and vomiting (5-9%) were more frequent with tirzepatide than glargine (nausea 2%, diarrhoea 4%, decreased appetite <1%, and vomiting 2%, respectively); most cases were mild to moderate and occurred during the dose-escalation phase. The percentage of participants with hypoglycaemia (glucose <54 mg/dL or severe) was lower with tirzepatide (6-9%) versus glargine (19%), particularly in participants not on sulfonylureas (tirzepatide 1-3% vs glargine 16%). Adjudicated MACE-4 events (cardiovascular death, myocardial infarction, stroke, hospitalisation for unstable angina) occurred in 109 participants and were not increased on tirzepatide compared with glargine (hazard ratio 0·74, 95% CI 0·51-1·08). 60 deaths (n=25 [3%] tirzepatide; n=35 [4%] glargine) occurred during the study.

INTERPRETATION

In people with type 2 diabetes and elevated cardiovascular risk, tirzepatide, compared with glargine, demonstrated greater and clinically meaningful HbA_1c reduction with a lower incidence of hypoglycaemia at week 52. Tirzepatide treatment was not associated with excess cardiovascular risk.

FUNDING

Eli Lilly and Company.

Efficacy and safety of novel twincretin tirzepatide a dual GIP and GLP-1 receptor agonist in the management of type-2 diabetes: A Cochrane meta-analysis

BACKGROUND

Till date, there is no Cochrane meta-analysis available which has analyzed efficacy and safety of tirzepatide in type-2 diabetes. This meta-analysis was undertaken to address this knowledge gap.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) involving people with diabetes receiving tirzepatide compared to a placebo/active comparator. Primary outcome was to evaluate changes in HbA1c. Secondary outcomes were to evaluate alterations in blood-glucose, glycemic targets, weight, lipids, and adverse events.

RESULTS

From 34 articles initially screened, data from six RCTs involving 3484 patients were analyzed. Over 12-52 weeks, individuals receiving tirzepatide had significantly greater lowering of HbA1c [mean difference (MD) = -0.75% (95% confidence interval (CI): -1.05 to -0.45); P < 0.01; I ² = 100%], fasting glucose [MD = -0.75 mmol/L (95% CI: -1.05 to- -0.45); P < 0.01; I ² = 100%], 2-h post-prandial-glucose [MD = -0.87 mmol/L (95% CI: -1.12 to -0.61); P < 0.01; I ² = 99%], weight [MD = -8.63 kg (95% CI: -12.89 to -4.36); P < 0.01; I ² = 100%], body mass index [MD = -1.80 kg/m² (95% CI: -2.39 to -1.21); P < 0.01; I ² = 99%], and waist circumference [MD = -4.43 cm (95% CI: -5.31 to -3.55); P < 0.01; I ² = 95%] as compared to dulaglutide, semaglutide, degludec, or glargine. Patients receiving tirzepatide had higher odds of achieving HbA1c <6.5% compared to active controls [odds ratio (OR) = 4.39 (95% CI: 2.44-7.92); P < 0.01; I ² = 90%]. Tirzepatide use had significantly higher odds of weight loss >5% [OR = 19.18 (95% CI: 2.34-157.17); P < 0.01; I ² = 99%], >10% [OR = 21.40 (95% CI: 2.36-193.94); P < 0.01; I ² = 98%], and >15% [OR = 32.84 (95% CI: 2.27-474.33); P = 0.01; I ² = 96%] compared to active-control group. Treatment-emergent adverse events [risk ratio (RR) = 1.43 (95% CI: 1.14-1.80); P < 0.01; I ² = 40%] and severe adverse events [RR = 1.00 (95% CI: 0.64-1.57); P = 1.00; I ² = 49%] were not different. High data heterogeneity and the presence of publication bias limits the grading of current data from "moderate to low."

CONCLUSION

Tirzepatide has impressive glycemic efficacy and weight-loss data over 1-year clinical use. The need for higher grade, long-term efficacy, and safety data remains.

The new dual gastric inhibitory peptide/glucagon-like peptide 1 agonist tirzepatide in type 2 diabetes: Is the future bright?

Tirzepatide is a dual gastric inhibitory peptide/glucagon-like peptide 1 (GIP/GLP-1) receptor agonist formulated as a synthetic linear peptide, based on the native GIP sequence. It has a prolonged half-life of 5 days, which enables once-weekly dosing. Studies have hitherto demonstrated its superiority in achieving optimal glycaemic control and body weight management, as compared with various agents used in the treatment of type 2 diabetes mellitus (T2DM), including GLP-1 receptor agonists. Thus, it is expected to enrich our therapeutic armamentarium in T2DM. However, further experience, notably longer follow-up data and information on cardiovascular effects, is still needed.