Efficacy and safety of glucagon-like peptide-1/glucagon receptor co-agonist JNJ-64565111 in individuals with obesity without type 2 diabetes mellitus: A randomized dose-ranging study

Class B1 GPCRs: insights into multireceptor pharmacology for the treatment of metabolic disease

The secretin-like, class B1 subfamily of seven transmembrane-spanning G protein-coupled receptors (GPCRs) consists of 15 members that coordinate important physiological processes. These receptors bind peptide ligands and use a distinct mechanism of activation that is driven by evolutionarily conserved structural features. For the class B1 receptors, the C-terminus of the cognate ligand is initially recognized by the receptor via an N-terminal extracellular domain that forms a hydrophobic ligand-binding groove. This binding enables the N-terminus of the ligand to engage deep into a large volume, open transmembrane pocket of the receptor. Importantly, the phylogenetic basis of this ligand-receptor activation mechanism has provided opportunities to engineer analogs of several class B1 ligands for therapeutic use. Among the most accepted of these are drugs targeting the glucagon-like peptide-1 (GLP-1) receptor for the treatment of type 2 diabetes and obesity. Recently, multifunctional agonists possessing activity at the GLP-1 receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor, such as tirzepatide, and others that also contain glucagon receptor activity, have been developed. In this article, we review members of the class B1 GPCR family with focus on receptors for GLP-1, GIP, and glucagon, including their signal transduction and receptor trafficking characteristics. The metabolic importance of these receptors is also highlighted, along with the benefit of polypharmacologic ligands. Furthermore, key structural features and comparative analyses of high-resolution cryogenic electron microscopy structures for these receptors in active-state complexes with either native ligands or multifunctional agonists are provided, supporting the pharmacological basis of such therapeutic agents.

The role of incretin receptor agonists in the treatment of obesity

INTRODRODUCTION

Obesity and its associated metabolic conditions have become a significant global health problem in recent years, with many people living with obesity fulfilling criteria for pharmacological treatment. The development of the glucagon-like peptide-1 receptor agonists for chronic weight management has triggered new interest in the incretins and other hormones as targets for obesity, and investigations into dual and triple co-agonists.

METHODS

The objective of this narrative review was to summarize the available data on approved and emerging incretin-based agents for the treatment of obesity.

RESULTS

In clinical trials of currently available agents in people with overweight or obesity, weight loss of between 6% and 21% of baseline body weight has been observed, with between 23% and 94% of participants achieving 10% or higher weight loss, depending on the study and the agent used. Favourable outcomes have also been seen with regard to cardiovascular risk and outcomes, diabetes prevention, metabolic dysfunction-associated steatotic liver disease/steatohepatitis and prevention of weight regain after metabolic surgery. Limitations associated with these agents include high costs, the potential for weight regain once treatment is stopped, the potential loss of lean body mass and gastrointestinal adverse events; potential issues with respect to gallbladder and biliary diseases require further investigation.

CONCLUSIONS

Many dual and triple co-agonists are still in development, and more data are needed to assess the efficacy, safety and tolerability of these emerging therapies versus the established incretin-based therapies; however, data are promising, and further results are eagerly awaited.

Incretin hormone agonists: Current and emerging pharmacotherapy for obesity management

Obesity continues to be a significant global health challenge, affecting over 800 million individuals worldwide. Traditional management strategies, including dietary, exercise, and behavioral interventions, often result in insufficient and unsustainable weight loss. Lifestyle modification remains the cornerstone of obesity management, providing the foundation for other strategies. While options such as bariatric surgery remain an effective intervention for severe obesity, it is associated with its own set of risks and is typically reserved for patients who have not achieved the desired results with pharmacotherapy and lifestyle interventions. Incretin hormone agonists represent a significant advancement in the pharmacotherapy of obesity, offering substantial weight reduction and cardiometabolic benefits. Agents like liraglutide, semaglutide, and tirzepatide supported by key clinical trials such as Satiety and Clinical Adipose Liraglutide Evidence (SCALE), Semaglutide Treatment Effect in People with Obesity (STEP) program trials, and Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) have demonstrated remarkable efficacy in promoting weight loss and improving metabolic outcomes. Additionally, novel therapies, including dual and triple incretin agonists, are under investigation and hold the potential for further advancements in obesity treatment. These novel therapies can be categorized by their mechanisms of action and route of administration into oral glucagon-like peptide-1 (GLP-1) receptor agonists, triple agonists (targeting GLP-1, glucose-dependent insulinotropic polypeptide [GIP], and glucagon receptors), and glucagon receptor-GLP-1 receptor co-agonists. Other innovative approaches include oral GIP-GLP-1 receptor co-agonists, and the combination of long-acting amylin receptor agonists with GLP-1 receptor agonists. The ongoing development of incretin-based therapies and the expanding availability of currently available agents are expected to enhance clinical outcomes further and reduce the burden of obesity-related health complications. This review aims to discuss the mechanisms and efficacy of current and emerging incretin hormone agonists for obesity management.

GLP-1 single, dual, and triple receptor agonists for treating type 2 diabetes and obesity: a narrative review

Obesity and type 2 diabetes mellitus (T2DM) present major global health challenges, with an increasing prevalence worldwide. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as a pivotal treatment option for both conditions, demonstrating efficacy in blood glucose management, weight reduction, cardiovascular disease prevention, and kidney health improvement. GLP-1, an incretin hormone, plays a crucial role in glucose metabolism and appetite regulation, influencing insulin secretion, insulin sensitivity, and gastric emptying. The therapeutic use of GLP-1RAs has evolved significantly, offering various formulations that provide different efficacy, routes of administration, and flexibility in dosing. These agents reduce HbA1c levels, facilitate weight loss, and exhibit cardiovascular protective effects, making them an integral component of T2DM and obesity management. This review will discuss the currently approved medication for T2DM and obesity, and will also highlight the advent of novel agents which are dual and triple hormonal agonists which represent the future direction of incretin-based therapy.

Funding

National Institutes of HealthNIDDKU24 DK132733 (FCS), UE5 DK137285 (FCS), and P30 DK040561 (FCS).

Glucagon agonism in the treatment of metabolic diseases including type 2 diabetes mellitus and obesity

Type 2 diabetes mellitus (T2DM) is associated with obesity and, therefore, it is important to target both overweight and hyperglycaemia. Glucagon plays important roles in glucose, amino acid and fat metabolism and may also regulate appetite and energy expenditure. These physiological properties are currently being exploited therapeutically in several compounds, most often in combination with glucagon-like peptide-1 (GLP-1) agonism in the form of dual agonists. With this combination, increases in hepatic glucose production and hyperglycaemia, which would be counterproductive, are largely avoided. In multiple randomized trials, the co-agonists have been demonstrated to lead to significant weight loss and, in participants with T2DM, even improved glycated haemoglobin (HbA1c) levels. In addition, significant reductions in hepatic fat content have been observed. Here, we review and discuss the studies so far available. Twenty-six randomized trials of seven different GLP-1 receptor (GLP-1R)/glucagon receptor (GCGR) co-agonists were identified and reviewed. GLP-1R/GCGR co-agonists generally provided significant weight loss, reductions in hepatic fat content, improved lipid profiles, insulin secretion and sensitivity, and in some cases, improved HbA1c levels. A higher incidence of adverse effects was present with GLP-1R/GCGR co-agonist treatment than with GLP-1 agonist monotherapy or placebo. Possible additional risks associated with glucagon agonism are also discussed. A delicate balance between GLP-1 and glucagon agonism seems to be of particular importance. Further studies exploring the optimal ratio of GLP-1 and glucagon receptor activation and dosage and titration regimens are needed to ensure a sufficient safety profile while providing clinical benefits.

GLP-1-based therapies for the treatment of resistant hypertension in individuals with overweight or obesity: a review

Despite the availability of a wide range of antihypertensive agents, a significant proportion of individuals with resistant hypertension (RHTN) struggle to achieve blood pressure (BP) control. Obesity ranks among the most significant modifiable risk factors for RHTN, with 56-91% of patients with RHTN classified as overweight or obese. Glucagon-like peptide-1 receptor agonist (GLP-1 RAs) are a class of anti-obesity medications that have recently demonstrated efficacy in reducing BP and improving cardiovascular (CV) outcomes in individuals with overweight or obesity. Among the available GLP-1-based therapies, liraglutide, semaglutide, and tirzepatide have been approved for chronic weight management in this population. Tirzepatide, a dual GLP-1 and glucose-dependent insulinotropic polypeptide receptor agonist, has the greatest effect on weight loss and BP reduction compared to GLP-1 RAs alone. To our knowledge, no trials have directly evaluated the effect of GLP-1 RAs or dual GLP-1/GIP receptor agonists on RHTN management. In this review article, we propose that targeting weight loss through GLP-1-based therapies should be explored as a treatment option for individuals with RHTN who are overweight or obese.

Comparison of the effects of Liraglutide, Tirzepatide, and Retatrutide on diabetic kidney disease in db/db mice

PURPOSE

To assess and compare the therapeutic efficacy of Liraglutide, Tirzepatide, and Retatrutide in treating diabetic kidney disease (DKD) in db/db mice.

METHODS

Db/db mice were administered intraperitoneal injections of Liraglutide (10 nmol/kg), Tirzepatide (10 nmol/kg), and Retatrutide (10 nmol/kg) for 10 weeks. Subsequently, we assessed the effectiveness of these three drugs in controlling blood glucose levels, reducing weight, and improving serum biochemical indicators and DKD. Additionally, we measured and compared the renal inflammation and fibrosis indexes. Meanwhile, the content of intestinal metabolite butyrate was compared to reflect the regulatory effects of these three drugs on gut microbiota.

RESULTS

Retatrutide demonstrated superior effectiveness in reducing weight and improving renal function in db/db mice compared to Liraglutide and Tirzepatide. Additionally, it markedly suppressed the expression of pro-inflammatory cytokines (TNF-α, caspase-1, and NLRP3) and pro-fibrotic factors (fibronectin, α-SMA, and collagen I) in the kidneys of mice. Furthermore, Retatrutide substantially enhanced liver function, reduced triglyceride levels, cholesterol levels, low-density lipoprotein cholesterol, elevated high-density lipoprotein cholesterol, and increased the content of intestinal metabolite butyrate in db/db mice when compared to the other two drugs. Unfortunately, despite its ability to lower blood glucose levels, Retatrutide did not outperform the other two drugs. In contrast, Tirzepatide exhibited better effects on lowering blood glucose, weight loss, lipid reduction, and improvement of DKD compared to Liraglutide.

CONCLUSIONS

Retatrutide and Tirzepatide were significantly effective in improving DKD, controlling blood glucose and body weight. Retatrutide was the most effective in improving DKD and body weight, while Tirzepatide was the most effective in controlling blood glucose. Inhibiting the expression of inflammatory factors and fibrosis mediators and regulating intestinal microbiota may be the potential mechanisms of these two drugs to delay the progression of DKD.

Transforming obesity: The advancement of multi-receptor drugs

For more than a century, physicians have searched for ways to pharmacologically reduce excess body fat. The tide has finally turned with recent advances in biochemically engineered agonists for the receptor of glucagon-like peptide-1 (GLP-1) and their use in GLP-1-based polyagonists. These polyagonists reduce body weight through complementary pharmacology by incorporating the receptors for glucagon and/or the glucose-dependent insulinotropic polypeptide (GIP). In their most advanced forms, gut-hormone polyagonists achieve an unprecedented weight reduction of up to ∼20%-30%, offering a pharmacological alternative to bariatric surgery. Along with favorable effects on glycemia, fatty liver, and kidney disease, they also offer beneficial effects on the cardiovascular system and adipose tissue. These new interventions, therefore, hold great promise for the future of anti-obesity medications.

Novel Therapeutics for Type 2 Diabetes Mellitus-A Look at the Past Decade and a Glimpse into the Future

Cardiovascular disease (CVD) and kidney disease are the main causes of morbidity and mortality in type 2 diabetes mellitus (T2DM). Globally, the incidence of T2DM continues to rise. A substantial increase in the burden of CVD and renal disease, alongside the socioeconomic implications, would be anticipated. Adopting a purely glucose-centric approach focusing only on glycemic targets is no longer adequate to mitigate the cardiovascular risks in T2DM. In the past decade, significant advancement has been achieved in expanding the pharmaceutical options for T2DM, with novel agents such as the sodium-glucose cotransporter type 2 (SGLT2) inhibitors and glucagon-like peptide receptor agonists (GLP-1 RAs) demonstrating robust evidence in cardiorenal protection. Combinatorial approaches comprising multiple pharmacotherapies combined in a single agent are an emerging and promising way to not only enhance patient adherence and improve glycemic control but also to achieve the potential synergistic effects for greater cardiorenal protection. In this review, we provide an update on the novel antidiabetic agents in the past decade, with an appraisal of the mechanisms contributing to cardiorenal protection. Additionally, we offer a glimpse into the landscape of T2DM management in the near future by providing a comprehensive summary of upcoming agents in early-phase trials.

Glucagon-based therapy for people with diabetes and obesity: What is the sweet spot?

People with obesity and type 2 diabetes have a high prevalence of metabolic-associated steatotic liver disease, hyperlipidemia and cardiovascular disease. Glucagon increases hepatic glucose production; it also decreases hepatic fat accumulation, improves lipidemia and increases energy expenditure. Pharmaceutical strategies to antagonize the glucagon receptor improve glycemic outcomes in people with diabetes and obesity, but they increase hepatic steatosis and worsen dyslipidemia. Co-agonism of the glucagon and glucagon-like peptide-1 (GLP-1) receptors has emerged as a promising strategy to improve glycemia in people with diabetes and obesity. Addition of glucagon receptor agonism enhances weight loss, reduces liver fat and ameliorates dyslipidemia. Prior to clinical use, however, further studies are needed to investigate the safety and efficacy of glucagon and GLP-1 receptor co-agonists in people with diabetes and obesity and related conditions, with specific concerns regarding a higher prevalence of gastrointestinal side effects, loss of muscle mass and increases in heart rate. Furthermore, co-agonists with differing ratios of glucagon:GLP-1 receptor activity vary in their clinical effect; the optimum balance is yet to be identified.

The role of glucagon-like peptide-1 receptor agonists in metabolic dysfunction-associated steatohepatitis

Despite its considerable and growing burden, there are currently no Food and Drug Administration-approved treatments for metabolic dysfunction-associated steatotic liver disease or its progressive form, metabolic dysfunction-associated steatohepatitis (MASH). Several glucagon-like peptide-1 receptor agonists (GLP-1RAs) and other agents are in various phases of clinical development for use in MASH; an ideal therapy should reduce liver fat content, improve chronic liver disease, help mitigate metabolic comorbidities and decrease all-cause mortality. Because of interconnected disease mechanisms, metabolic dysfunction-associated steatotic liver disease/MASH often coexists with type 2 diabetes (T2D), obesity and cardiovascular disease. Various GLP-1RAs are Food and Drug Administration-approved for use in T2D, and two, liraglutide and semaglutide, are approved for overweight and obesity. GLP-1RAs decrease glucose levels and body weight and improve cardiovascular outcomes in people with T2D who are at high risk of cardiovascular disease. In addition, GLP-1RAs have been reported to reduce liver fat content and liver enzymes, reduce oxidative stress and improve hepatic de novo lipogenesis and the histopathology of MASH. Weight loss may contribute to these effects; however, the exact mechanisms are unknown. Adverse events that are commonly associated with GLP-1RAs include vomiting, nausea and diarrhoea. There is a lack of evidence from meta-analyses regarding the increased risk of acute pancreatitis and various forms of cancer with GLP-1RAs. Large-scale, phase 3 trials, which will provide definitive data on GLP-1RAs and other potential therapies in MASH, are ongoing. Given the spectrum of modalities under investigation, it is hoped that these trials will support the identification of pharmacotherapies that provide clinical benefit for patients with MASH.

Role of lifestyle and glucagon-like peptide-1 receptor agonists for weight loss in obesity, type 2 diabetes and steatotic liver diseases

BACKGROUND

The current obesity pandemic has given rise to associated comorbidities and complications, including type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). During the last decade, certain glucagon-like peptide 1 receptor agonists (GLP-1RA), originally developed as antihyperglycemic drugs, also demonstrated efficacy for weight loss.

AIMS

To review shared pathophysiologic features of common metabolic diseases and compare therapeutic strategies to reduce body weight and related complications.

METHODS

We performed an extensive literature research to describe the effects of lifestyle modification, first-generation anti-obesity drugs, and GLP-1RA on weight loss in humans with obesity, type 2 diabetes and MASLD.

RESULTS

Until recently, treatment of obesity has been limited to lifestyle modification, which offer moderate degree and sustainability of weight loss. The few approved first-generation anti-obesity drugs are either limited to short term use or to certain forms of obesity. Some GLP-1RA significantly decrease caloric intake and body weight. Liraglutide and semaglutide have therefore been approved for treating people with obesity. They also lead to a reduction of hepatic fat content and inflammation in people with biopsy-confirmed MASLD. Possible limitations comprise adverse effects, treatment adherence and persistence.

CONCLUSION

Certain GLP-1RA are superior to lifestyle modification and first-generation anti-obesity drugs in inducing weight loss. They have therefore markedly changed the portfolio of obesity treatment with additional beneficial effects on steatotic liver disease.

Incretin-based investigational therapies for the treatment of MASLD/MASH

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most common form of chronic liver disease. It exists as either simple steatosis or its more progressive form, metabolic dysfunction-associated steatohepatitis (MASH), formerly, non-alcoholic steatohepatitis (NASH). The global prevalence of MASLD is estimated to be 32% among adults and is projected to continue to rise with increasing rates of obesity, type 2 diabetes, and metabolic syndrome. While simple steatosis is often considered benign and reversible, MASH is progressive, potentially leading to the development of cirrhosis, liver failure, and hepatocellular carcinoma. Treatment of MASH is therefore directed at slowing, stopping, or reversing the progression of disease. Evidence points to improved liver histology with therapies that result in sustained body weight reduction. Incretin-based molecules, such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs), alone or in combination with glucose-dependent insulinotropic polypeptide (GIP) and/or glucagon receptor agonists, have shown benefit here, and several are under investigation for MASLD/MASH treatment. In this review, we discuss current published data on GLP-1, GIP/GLP-1, GLP-1/glucagon, and GLP-1/GIP/glucagon RAs in MASLD/MASH, focusing on their efficacy on liver histology, liver fat, and MASH biomarkers.

Management of type 2 diabetes, obesity, or nonalcoholic steatohepatitis with high-dose GLP-1 receptor agonists and GLP-1 receptor-based co-agonists

Type 2 diabetes (T2D), obesity, and nonalcoholic fatty liver disease/nonalacoholic steatohepatitis (NAFLD/NASH) share mutual causalities. Medications that may offer clinical benefits to all three conditions are being developed. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are approved for the management of T2D and obesity and there is great interest in evaluating higher doses of available GLP-1RAs and developing novel GLP-1RA-based co-agonists to provide greater reductions in glycated hemoglobin (HbA1c) and body weight as well as modifying NAFLD/NASH complications in clinically meaningful ways. High-dose GLP-1RAs and multi-hormonal strategies including GLP-1R agonism have either already been approved or are in development for managing T2D, obesity, or NASH. We provide a mechanistic outline with a detailed summary of the available clinical data and ongoing trials that are adjudicating the impact of high-dose GLP-1RAs, unimolecular, and multimolecular GLP-1R-based co-agonists in populations living with T2D, obesity, or NASH. The available trial findings are aligned with preclinical observations, showing clinical efficacy and safety thus providing optimism for the expansion of GLP-1R-based drug classes for managing the triad of T2D, obesity and NASH. Development, access, and wide-spread utilization of these new therapeutic approaches will offer important opportunities to markedly improve the collective global burden of T2D, obesity, and NASH.

Efficacy and safety of Mazdutide on weight loss among diabetic and non-diabetic patients: a systematic review and meta-analysis of randomized controlled trials

Background

Overweight and obesity are increasing global public health problems. Mazdutide is a new dual agonist drug that can potentially reduce weight and blood glucose levels simultaneously. However, the synthesis of evidence on the efficacy and safety of this drug is scarce. Therefore, this study aimed to synthesize evidence on the efficacy and safety of Mazdutide compared to placebo on weight reduction among adults with and without diabetes.

Methods

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). Data were retrieved from six electronic databases: PubMed, Web of Science, Scopus, Cochrane Library, ClinicalTrial.gov, and Google Scholar, and manually searched from the included references. The data were synthesized using a random effect model. This analysis was performed in the R programming language using the Meta package.

Results

A total of seven RCTs involving 680 participants were included in this study. Mazdutide was more effective in reducing body weight (mean difference [MD]= -6.22%, 95% confidence interval [CI]: -8.02% to -4.41%, I2 = 90.0%), systolic blood pressure (MD = -7.57 mmHg, 95% CI: -11.17 to -3.98 mmHg, I2 = 46%), diastolic blood pressure (MD = -2.98 mmHg, 95% CI: -5.74 to -0.22 mmHg, I2 = 56%), total cholesterol (MD = -16.82%, 95% CI: -24.52 to -9.13%, I2 = 61%), triglycerides (MD = -43.29%, 95% CI: -61.57 to -25.01%, I2 = 68%), low-density lipoprotein (MD= -17.07%, 95% CI: -25.54 to -8.60%, I2 = 53%), and high-density lipoprotein (MD = -7.54%, 95% CI: -11.26 to -3.83%, I2 = 0%) than placebo. Mazdutide was associated with reduced hemoglobin A1c (HbA1c) and fasting plasma glucose in participants with type 2 diabetes. In the subgroup and meta-regression analyses, weight reduction was more significant in non-diabetics compared to diabetics, and in those who received a longer treatment duration (24 weeks) than in those on shorter durations (12-20 weeks). Participants who received Mazdutide had a higher risk of transient mild or moderate gastrointestinal side effects.

Conclusion

Mazdutite appears to be effective in weight reduction among patients with and without diabetes, and it has an advantage over other associated comorbidities. However, it was associated with mild or moderate gastrointestinal side effects.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=403859, identifier CRD42023403859.

A GIPR antagonist conjugated to GLP-1 analogues promotes weight loss with improved metabolic parameters in preclinical and phase 1 settings

Obesity is a major public health crisis. Multi-specific peptides have emerged as promising therapeutic strategies for clinical weight loss. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are endogenous incretins that regulate weight through their receptors (R). AMG 133 (maridebart cafraglutide) is a bispecific molecule engineered by conjugating a fully human monoclonal anti-human GIPR antagonist antibody to two GLP-1 analogue agonist peptides using amino acid linkers. Here, we confirm the GIPR antagonist and GLP-1R agonist activities in cell-based systems and report the ability of AMG 133 to reduce body weight and improve metabolic markers in male obese mice and cynomolgus monkeys. In a phase 1, randomized, double-blind, placebo-controlled clinical study in participants with obesity ( NCT04478708 ), AMG 133 had an acceptable safety and tolerability profile along with pronounced dose-dependent weight loss. In the multiple ascending dose cohorts, weight loss was maintained for up to 150 days after the last dose. These findings support continued clinical evaluation of AMG 133.

What is the pipeline for future medications for obesity?

Obesity is a chronic disease associated with increased risk of obesity-related complications and mortality. Our better understanding of the weight regulation mechanisms and the role of gut-brain axis on appetite has led to the development of safe and effective entero-pancreatic hormone-based treatments for obesity such as glucagon-like peptide-1 (GLP-1) receptor agonists (RA). Semaglutide 2.4 mg once weekly, a subcutaneously administered GLP-1 RA approved for obesity treatment in 2021, results in 15-17% mean weight loss (WL) with evidence of cardioprotection. Oral GLP-1 RA are also under development and early data shows similar WL efficacy to semaglutide 2.4 mg. Looking to the next generation of obesity treatments, combinations of GLP-1 with other entero-pancreatic hormones with complementary actions and/or synergistic potential (such as glucose-dependent insulinotropic polypeptide (GIP), glucagon, and amylin) are under investigation to enhance the WL and cardiometabolic benefits of GLP-1 RA. Tirzepatide, a dual GLP-1/GIP receptor agonist has been approved for glycaemic control in type 2 diabetes as well as for obesity management leading in up to 22.5% WL in phase 3 obesity trials. Other combinations of entero-pancreatic hormones including cagrisema (GLP-1/amylin RA) and the triple agonist retatrutide (GLP-1/GIP/glucagon RA) have also progressed to phase 3 trials as obesity treatments and early data suggests that may lead to even greater WL than tirzepatide. Additionally, agents with different mechanisms of action to entero-pancreatic hormones (e.g. bimagrumab) may improve the body composition during WL and are in early phase clinical trials. We are in a new era for obesity pharmacotherapy where combinations of entero-pancreatic hormones approach the WL achieved with bariatric surgery. In this review, we present the efficacy and safety data for the pipeline of obesity pharmacotherapies with a focus on entero-pancreatic hormone-based treatments and we consider the clinical implications and challenges that the new era in obesity management may bring.

Efficacy and safety of GLP-1RAs for people with obesity: A systematic review based on RCT and Bayesian network meta-analysis

BACKGROUND

GLP-1 receptor agonists (GLP-1RAs) reduce glucagon and glycogen secretion, inhibit appetite and slow gastric empties and have recently been approved to treat obesity.

OBJECTIVE

To explore the safety and efficacy of GLP-1RAs in the treatment of obesity and clarify the optimal GLP-1RAs treatment regimen.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases were searched for English randomized controlled trials (RCTs) on GLP-1RAs in the treatment and management of obesity published before July 18, 2023. Literature screening and data extraction were performed independently by three researchers. Bayesian random effect model was used to compare the effects of interventions. Continuous variables were expressed as mean difference with 95% CI, and dichotomous variables were reported as RR with 95% CI.

RESULTS

A total of 29 studies with 10,333 participants were included in the present study. The combination of cagrilintide and semaglutide (short for cagrANDsema) was an optimal strategy for weight loss and glycosylated hemoglobin (HbA1c) reduction. Compared to placebo, cagrANDsema reduced weight by - 14.13 kg (95% CI: -16.49, -11.73) and HbA1c by - 0.33% (95% CI: -0.41, -0.25). Moreover, this study indicated that orforglipron and semaglutide also had relatively good effects on weight loss. Meta-regression results indicated that higher dose levels might have better effects on weight loss.

CONCLUSIONS

CagrANDsema exerts the best effect for weight loss. In terms of current dose levels, a higher dose gets better weight-loss effects without increasing the risk of adverse events.

Glucagon-like peptide agonists: A prospective review

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as promising therapeutic options for addressing Type-2 diabetes, obesity, and related conditions. Among these, semaglutide, tirzepatide, liraglutide etc., all notable GLP-1RA, have gained attention owing to their favourable pharmacological properties and clinical efficacy.

AIMS

This comprehensive review aims to provide a detailed analysis of both the currently available GLP-1RAs in the market and those undergoing clinical trials. The focus is on examining their mechanism of action, pharmacokinetics, efficacy in glycemic control and weight management, safety profile, and potential applications.

MATERIALS & METHODS

The review employs a systematic approach to gather information on GLP-1RAs. Relevant literature from the currently literature and ongoing clinical trials is thoroughly examined. Detailed scrutiny is applied to understand the mechanism of action, pharmacokinetic properties, and clinical outcomes of these agents.

RESULTS

The review presents a comprehensive overview of the GLP-1RAs, highlighting their distinct mechanisms of action, pharmacokinetic profiles, and clinical effectiveness in glycemic control and weight management. Safety profiles are also discussed, providing a holistic understanding of these therapeutic agents.

DISCUSSION

The findings are discussed in the context of advancements in the field of GLP-1RAs. Potential applications beyond diabetes and obesity are explored, shedding light on the broader implications of these agents in managing related conditions.

CONCLUSION

In conclusion, this review underscores the significance of GLP-1RAs, with a specific focus on semaglutide, in the management of type 2 diabetes, obesity, and beyond. By synthesizing information on their mechanisms, pharmacokinetics, efficacy, and safety, this review provides valuable insights into the potential benefits these agents offer, contributing to the ongoing discourse in the field.

A phase 2 randomised controlled trial of mazdutide in Chinese overweight adults or adults with obesity

Mazdutide is a once-weekly glucagon-like peptide-1 (GLP-1) and glucagon receptor dual agonist. We evaluated the efficacy and safety of 24-week treatment of mazdutide up to 6 mg in Chinese overweight adults or adults with obesity, as an interim analysis of a randomised, two-part (low doses up to 6 mg and high dose of 9 mg), double-blind, placebo-controlled phase 2 trial (ClinicalTrials.gov, NCT04904913). Overweight adults (body-mass index [BMI] ≥24 kg/m2) accompanied by hyperphagia and/or at least one obesity-related comorbidity or adults with obesity (BMI ≥ 28 kg/m2) were randomly assigned (3:1:3:1:3:1) to once-weekly mazdutide 3 mg, 4.5 mg, 6 mg or matching placebo at 20 hospitals in China. The primary endpoint was the percentage change from baseline to week 24 in body weight. A total of 248 participants were randomised to mazdutide 3 mg (n = 62), 4.5 mg (n = 63), 6 mg (n = 61) or placebo (n = 62). The mean percentage changes from baseline to week 24 in body weight were -6.7% (SE 0.7) with mazdutide 3 mg, -10.4% (0.7) with 4.5 mg, -11.3% (0.7) with 6 mg and 1.0% (0.7) with placebo, with treatment difference versus placebo ranging from -7.7% to -12.3% (all p < 0.0001). All mazdutide doses were well tolerated and the most common adverse events included diarrhoea, nausea and upper respiratory tract infection. In summary, in Chinese overweight adults or adults with obesity, 24-week treatment with mazdutide up to 6 mg was safe and led to robust and clinically meaningful body weight reduction.

MASLD treatment-a shift in the paradigm is imminent

MASLD prevalence is growing towards the leading cause of end-stage liver disease. Up to today, the most effective treatment is weight loss. Weight loss interventions are moving from lifestyle changes to bariatric surgery or endoscopy, and, more recently, to a new wave of anti-obesity drugs that can compete with bariatric surgery. Liver-targeted therapy is a necessity for those patients who already present liver fibrosis. The field is moving fast, and in the near future, we will testify to a disruptive change in MASLD treatment, similar to the paradigm-shift that occurred for hepatitis C almost one decade ago with direct antiviral agents.

Results from three phase 1 trials of NNC9204-1177, a glucagon/GLP-1 receptor co-agonist: Effects on weight loss and safety in adults with overweight or obesity

OBJECTIVE

Glucagon/glucagon-like peptide-1 (GLP-1) receptor co-agonists may provide greater weight loss than agonists targeting the GLP-1 receptor alone. We report results from three phase 1 trials investigating the safety, tolerability, pharmacokinetics and pharmacodynamics of the glucagon/GLP-1 receptor co-agonist NNC9204-1177 (NN1177) for once-weekly subcutaneous use in adults with overweight or obesity.

METHODS

Our focus was a 12-week, multiple ascending dose (MAD), placebo-controlled, double-blind trial in which adults (N = 99) received NN1177 (on an escalating dose regimen of 200, 600, 1300, 1900, 2800, 4200 and 6000 μg) or placebo. Two other trials also contributed to the findings reported in this article: a first human dose (FHD)/single ascending dose (SAD), placebo-controlled, double-blind trial in which adults (N = 49) received NN1177 (treatment doses of 10, 40, 120, 350, 700 and 1100 μg) or placebo, and a drug-drug interaction, open-label, single-sequence trial in which adults (N = 45) received a 4200-μg dose of NN1177, following administration of a Cooperstown 5 + 1 index cocktail. Safety, tolerability, pharmacokinetic and pharmacodynamic endpoints were assessed.

RESULTS

For the FHD/SAD and MAD trials, baseline characteristics were generally balanced across treatment cohorts. The geometric mean half-life of NN1177 at steady state was estimated at between 77 and 111 h, and clinically relevant weight loss was achieved (up to 12.6% at week 12; 4200 μg in the MAD trial). Although NN1177 appeared tolerable across trials, several unexpected treatment-related safety signals were observed; increased heart rate, decreased reticulocyte count, increased markers of inflammation (fibrinogen and C-reactive protein), increased aspartate and alanine aminotransferase, impaired glucose tolerance and reduced blood levels of some amino acids.

CONCLUSION

Although treatment with NN1177 was associated with dose-dependent and clinically relevant weight loss, the observed safety signals precluded further clinical development.

Mechanisms of action of incretin receptor based dual- and tri-agonists in pancreatic islets

Simultaneous activation of the incretin G-protein-coupled receptors (GPCRs) via unimolecular dual-receptor agonists (UDRA) has emerged as a new therapeutic approach for type 2 diabetes. Recent studies also advocate triple agonism with molecules also capable of binding the glucagon receptor. In this scoping review, we discuss the cellular mechanisms of action (MOA) underlying the actions of these novel and therapeutically important classes of peptide receptor agonists. Clinical efficacy studies of several UDRAs have demonstrated favorable results both as monotherapies and when combined with approved hypoglycemics. Although the additive insulinotropic effects of dual glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic peptide receptor (GIPR) agonism were anticipated based on the known actions of either glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic peptide (GIP) alone, the additional benefits from GCGR were largely unexpected. Whether additional synergistic or antagonistic interactions among these G-protein receptor signaling pathways arise from simultaneous stimulation is not known. The signaling pathways affected by dual- and tri-agonism require more trenchant investigation before a comprehensive understanding of the cellular MOA. This knowledge will be essential for understanding the chronic efficacy and safety of these treatments.

A phase IIa active-comparator-controlled study to evaluate the efficacy and safety of efinopegdutide in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

This study assessed the effects of the glucagon-like peptide-1 (GLP-1)/glucagon receptor co-agonist efinopegdutide relative to the selective GLP-1 receptor agonist semaglutide on liver fat content (LFC) in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

This was a phase IIa, randomized, active-comparator-controlled, parallel-group, open-label study. A magnetic resonance imaging-estimated proton density fat fraction assessment was performed to determine LFC at screening and Week 24. Participants with an LFC of ≥10% at screening were randomized 1:1 to efinopegdutide 10 mg or semaglutide 1 mg, both administered subcutaneously once weekly for 24 weeks. Participants were stratified according to the concurrent diagnosis of type 2 diabetes mellitus (T2DM). Both drugs were titrated to the target dose over an 8-week time period. The primary efficacy endpoint was relative reduction from baseline in LFC (%) after 24 weeks of treatment.

RESULTS

Among 145 randomized participants (efinopegdutide n = 72, semaglutide n = 73), 33.1% had T2DM. At baseline, mean BMI was 34.3 kg/m2 and mean LFC was 20.3%. The least squares (LS) mean relative reduction from baseline in LFC at Week 24 was significantly (p <0.001) greater with efinopegdutide (72.7% [90% CI 66.8-78.7]) than with semaglutide (42.3% [90% CI 36.5-48.1]). Both treatment groups had an LS mean percent reduction from baseline in body weight at Week 24 (efinopegdutide 8.5% vs. semaglutide 7.1%; p = 0.085). Slightly higher incidences of adverse events and drug-related adverse events were observed in the efinopegdutide group compared with the semaglutide group, primarily related to an imbalance in gastrointestinal adverse events.

CONCLUSIONS

In patients with NAFLD, treatment with efinopegdutide 10 mg weekly led to a significantly greater reduction in LFC than semaglutide 1 mg weekly.

CLINICAL TRIAL NUMBER

EudraCT: 2020-005136-30; NCT: 04944992.

IMPACT AND IMPLICATIONS

Currently, there are no approved therapies for non-alcoholic steatohepatitis (NASH). The weight loss associated with glucagon-like peptide-1 (GLP-1) receptor agonists has been shown to decrease hepatic inflammation in patients with NASH. In addition to reducing liver fat content (LFC) indirectly through weight loss, glucagon receptor agonism may also reduce LFC by acting on the liver directly to stimulate fatty acid oxidation and reduce lipogenesis. This study demonstrated that treatment of patients with non-alcoholic fatty liver disease with the GLP-1/glucagon receptor co-agonist efinopegdutide (10 mg weekly) led to a significantly greater reduction in LFC compared to treatment with the GLP-1 receptor agonist semaglutide (1 mg weekly), suggesting that efinopegdutide may be an effective treatment for NASH.

GIPR/GLP-1R dual agonist therapies for diabetes and weight loss-chemistry, physiology, and clinical applications

The incretin system is an essential metabolic axis that regulates postprandial metabolism. The two incretin peptides that enable this effect are the glucose-dependent insulinotropic polypeptide (GIP) and the glucagon-like peptide 1 (GLP-1), which have cognate receptors (GIPR and GLP-1R) on islet β cells as well as in other tissues. Pharmacologic engagement of the GLP-1R is a proven strategy for treating hyperglycemia in diabetes and reducing body weight. Tirzepatide is the first monomeric peptide with dual activity at both incretin receptors now available for clinical use, and in clinical trials it has shown unprecedented effects to reduce blood glucose and body weight. Here, we discuss the foundational science that led to the development of monomeric multi-incretin receptor agonists, culminating in the development of tirzepatide. We also look to the future of this field and comment on how the concept of multi-receptor agonists will continue to progress for the treatment of metabolic disease.

The Weight-loss Effect of GLP-1RAs Glucagon-Like Peptide-1 Receptor Agonists in Non-diabetic Individuals with Overweight or Obesity: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are new drugs for the treatment of obesity.

OBJECTIVE

To assess the weight-loss effects of GLP-1RAs in the treatment of patients with overweight or obesity without diabetes.

METHODS

This is a systematic review with meta-analysis and trial sequential analysis. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from their inception to January 1, 2022. Eligible trials report on outcomes including body weight (BW), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), or total body fat (TBF). Mean differences (MDs) and standardized mean differences (SMDs) were summarized using random-effects models.

RESULTS

Forty-one trials involving 15,135 participants were included. Compared with controls, GLP-1RAs significantly reduced BW (MD -5.319 kg, 95% CI: -6.465, -4.174), BMI (MD -2.373 kg/m2, 95% CI: -2.821, -1.924), WC (MD -4.302 cm, CI:-5.185 to -3.419), WHR (MD -0.011, CI -0.015 to -0.007), but not TBF (MD -0.320%, CI -1.420 to -0.780). Trial sequential analysis (TSA) supported conclusive evidence of the effects of GLP-1RAs on BW, BMI, and WC for weight loss. GLP-1RAs had nonlinear dose-response relationships with weight loss. Extensive sensitivity analyses demonstrated the robustness of the results, though the GRADE certainty of the evidence ranged from high to very low. High to moderate GRADE certainty of evidence suggested semaglutide as the most effective GLP-1RA agent, with the best efficacy and low to moderate risk of adverse effects.

CONCLUSIONS

The present study provides conclusive evidence for the effect of GLP-1RAs on weight loss in a nonlinear dose-response manner in patients with obesity or overweight without diabetes. In terms of changes in BW, BMI, and WC, there is firm evidence for the overall weight-loss effects of GLP-1RAs. Of the GLP-1RAs, semaglutide might be the most effective agent.

Future therapies for obesity

Obesity is a chronic disease associated with increased morbidity and mortality. Bariatric surgery can lead to sustained long-term weight loss (WL) and improvement in multiple obesity-related complications, but it is not scalable at the population level. Over the past few years, gut hormone-based pharmacotherapies for obesity and type 2 diabetes mellitus (T2DM) have rapidly evolved, and combinations of glucagon-like peptide 1 (GLP1) with other gut hormones (glucose-dependent insulinotropic polypeptide (GIP), glucagon, and amylin) as dual or triple agonists are under investigation to enhance and complement the effects of GLP1 on WL and obesity-related complications. Tirzepatide, a dual agonist of GLP1 and GIP receptors, marks a new era in obesity pharmacotherapy in which a combination of gut hormones could approach the WL achieved with bariatric surgery. In this review, we discuss emerging obesity treatments with a focus on gut hormone combinations and the concept of a multimodal approach for obesity management.

The molecular pharmacology of glucagon agonists in diabetes and obesity

Within recent decades glucagon receptor (GcgR) agonism has drawn attention as a therapeutic tool for the treatment of type 2 diabetes and obesity. In both mice and humans, glucagon administration enhances energy expenditure and suppresses food intake suggesting a promising metabolic utility. Therefore synthetic optimization of glucagon-based pharmacology to further resolve the physiological and cellular underpinnings mediating these effects has advanced. Chemical modifications to the glucagon sequence have allowed for greater peptide solubility, stability, circulating half-life, and understanding of the structure-function potential behind partial and "super"-agonists. The knowledge gained from such modifications has provided a basis for the development of long-acting glucagon analogues, chimeric unimolecular dual- and tri-agonists, and novel strategies for nuclear hormone targeting into glucagon receptor-expressing tissues. In this review, we summarize the developments leading toward the current advanced state of glucagon-based pharmacology, while highlighting the associated biological and therapeutic effects in the context of diabetes and obesity.

Safety, tolerability, pharmacokinetics and pharmacodynamics of multiple ascending doses of the novel long-acting glucagon analogue HM15136 in overweight and obese patients with co-morbidities

AIM

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of multiple ascending doses of the novel long-acting glucagon analogue HM15136 in overweight/obese patients with co-morbidities, with and without type 2 diabetes (T2D).

MATERIALS AND METHODS

This was a phase 1, double-blind, randomized, placebo-controlled, two-part trial with a 12-week treatment period of once-weekly subcutaneous HM15136 (0.02/0.04/0.06 mg/kg). Part 1 included patients with dyslipidaemia and/or hypertension and no T2D. Part 2 included patients with dyslipidaemia and/or hypertension plus T2D.

RESULTS

In part 1, 23/27 (85.2%) patients receiving HM15136 and all patients receiving placebo (9/9 [100%]) experienced a treatment-emergent adverse event (TEAE). Five of 27 (18.5%) patients receiving HM15136 developed anti-HM15136 antibodies. Dose-dependent increases in mean HM15136 serum concentration and fasting plasma glucose (FPG) were observed, as were dose-dependent weight reductions of 0.5%/2.3%/2.6% at doses of 0.02/0.04/0.06 mg/kg, respectively. In part 2, 8/12 (66.7%) patients receiving HM15136 and all patients receiving placebo (4/4 [100.0%]) reported a TEAE. Two (16.7%) patients developed anti-HM15136 antibodies. Dose-dependent increases in mean HM15136 serum concentration were observed. FPG of more than 200 mg/dL was reported in 4/9 (44.4%) and 2/3 (66.7%) patients receiving 0.02 and 0.06 mg/kg, respectively. The 0.06 mg/kg dose was not tolerated in part 2 because of hyperglycaemia. Patients receiving 0.02 mg/kg showed a 0.9% weight reduction. No serious TEAEs leading to discontinuation were reported in either study part.

CONCLUSIONS

This study of HM15136 provides a preliminary safety and tolerability profile with initial insights into its efficacy profile.

Emerging roles of oxyntomodulin-based glucagon-like peptide-1/glucagon co-agonist analogs in diabetes and obesity

Oxyntomodulin (OXM) is an endogenous peptide hormone secreted from the intestines following nutrient ingestion that activates both glucagon-like peptide-1 (GLP-1) and glucagon receptors. OXM is known to exert various effects, including improvement in glucose tolerance, promotion of energy expenditure, acceleration of liver lipolysis, inhibition of food intake, delay of gastric emptying, neuroprotection, and pain relief. The antidiabetic and antiobesity properties have led to the development of biologically active and enzymatically stable OXM-based analogs with proposed therapeutic promise for metabolic diseases. Structural modification of OXM was ongoing to enhance its potency and prolong half-life, and several GLP-1/glucagon dual receptor agonist-based therapies are being explored in clinical trials for the treatment of type 2 diabetes mellitus and its complications. In the present article, we provide a brief overview of the physiology of OXM, focusing on its structural-activity relationship and ongoing clinical development.

Revisiting the role of glucagon in health, diabetes mellitus and other metabolic diseases

Insulin and glucagon exert opposing effects on glucose metabolism and, consequently, pancreatic islet β-cells and α-cells are considered functional antagonists. The intra-islet hypothesis has previously dominated the understanding of glucagon secretion, stating that insulin acts to inhibit the release of glucagon. By contrast, glucagon is a potent stimulator of insulin secretion and has been used to test β-cell function. Over the past decade, α-cells have received increasing attention due to their ability to stimulate insulin secretion from neighbouring β-cells, and α-cell-β-cell crosstalk has proven central for glucose homeostasis in vivo. Glucagon is not only the counter-regulatory hormone to insulin in glucose metabolism but also glucagon secretion is more susceptible to changes in the plasma concentration of certain amino acids than to changes in plasma concentrations of glucose. Thus, the actions of glucagon also include a central role in amino acid turnover and hepatic fat oxidation. This Review provides insights into glucagon secretion, with a focus on the local paracrine actions on glucagon and the importance of α-cell-β-cell crosstalk. We focus on dysregulated glucagon secretion in obesity, non-alcoholic fatty liver disease and type 2 diabetes mellitus. Lastly, the future potential of targeting hyperglucagonaemia and applying dual and triple receptor agonists with glucagon receptor-activating properties in combination with incretin hormone receptor agonism is discussed.

Glucagon-like Peptide-1 Receptor-based Therapeutics for Metabolic Liver Disease

Glucagon-like peptide-1 (GLP-1) controls islet hormone secretion, gut motility, and body weight, supporting development of GLP-1 receptor agonists (GLP-1RA) for the treatment of type 2 diabetes (T2D) and obesity. GLP-1RA exhibit a favorable safety profile and reduce the incidence of major adverse cardiovascular events in people with T2D. Considerable preclinical data, supported by the results of clinical trials, link therapy with GLP-RA to reduction of hepatic inflammation, steatosis, and fibrosis. Mechanistically, the actions of GLP-1 on the liver are primarily indirect, as hepatocytes, Kupffer cells, and stellate cells do not express the canonical GLP-1R. GLP-1RA reduce appetite and body weight, decrease postprandial lipoprotein secretion, and attenuate systemic and tissue inflammation, actions that may contribute to attenuation of metabolic-associated fatty liver disease (MAFLD). Here we discuss evolving concepts of GLP-1 action that improve liver health and highlight evidence that links sustained GLP-1R activation in distinct cell types to control of hepatic glucose and lipid metabolism, and reduction of experimental and clinical nonalcoholic steatohepatitis (NASH). The therapeutic potential of GLP-1RA alone, or in combination with peptide agonists, or new small molecule therapeutics is discussed in the context of potential efficacy and safety. Ongoing trials in people with obesity will further clarify the safety of GLP-1RA, and pivotal studies underway in people with NASH will define whether GLP-1-based medicines represent effective and safe therapies for people with MAFLD.

Obesity pharmacotherapy: incretin action in the central nervous system

The prevalence of obesity is rising, creating an urgent need for efficacious therapies. Recent clinical trials show that tirzepatide, a dual agonist of receptors for the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), yields more weight loss than selective GLP-1 receptor (GLP-1R) agonists. Incretin receptors in the central nervous system (CNS) may contribute to these effects. Yet exactly how each receptor regulates body weight from within the CNS is not clearly understood. It remains especially unclear how GIP receptor (GIPR) signalling contributes to the effects of tirzepatide because both stimulation and inhibition of CNS GIPRs yield weight loss in preclinical models. We summarise current knowledge on CNS incretin receptor pharmacology to provide insight into the potential mechanisms of action of dual GIPR/GLP-1R agonists, with tirzepatide as the exemplar. In addition, we discuss recent developments in incretin-based dual- and tri-agonism for inducing weight loss in obese individuals.

Safety and efficacy of a GLP-1 and glucagon receptor dual agonist mazdutide (IBI362) 9 mg and 10 mg in Chinese adults with overweight or obesity: A randomised, placebo-controlled, multiple-ascending-dose phase 1b trial

Background

Mazdutide (also known as IBI362 or LY3305677), a novel once-weekly glucagon-like peptide-1 (GLP-1) and glucagon receptor dual agonist, achieved 12-week body weight loss up to 6.4% at doses up to 6 mg in Chinese adults with overweight or obesity. We further explored the safety and efficacy of mazdutide dosed up to 9 mg and 10 mg.

Methods

In this randomised, placebo-controlled, multiple-ascending-dose phase 1b trial, we enrolled adults (aged 18-75 years, both inclusive) with overweight (body-mass index [BMI] ≥24 kg/m2) accompanied by hyperphagia and/or at least one obesity-related comorbidity or obesity (BMI ≥28 kg/m2) from five hospitals in China. Eligible participants were randomly assigned (2:1) within each cohort by using an interactive web-response system to receive once-weekly subcutaneous mazdutide or placebo for 12 weeks in the 9 mg cohort (3 mg weeks 1-4; 6 mg weeks 5-8; 9 mg weeks 9-12) and for 16 weeks in the 10 mg cohort (2.5 mg weeks 1-4; 5 mg weeks 5-8; 7.5 mg weeks 9-12; 10 mg weeks 13-16). The participants, investigators, study site personnel involved in treating and assessing participants in each cohort and sponsor personnel were masked to treatment allocation. The primary outcomes were safety and tolerability of mazdutide, assessed from baseline to end of follow-up in all participants who received at least one dose of the study treatment. The secondary outcomes included the change from baseline to week 12 or week 16 in body weight, waist circumference and BMI. This trial is registered with ClinicalTrials.gov, NCT04440345.

Findings

Between Mar. 1, 2021 and Mar. 26, 2021, a total of 24 participants were enrolled, with eight randomly assigned to mazdutide and four to placebo in each cohort. One participant receiving mazdutide and two receiving placebo in the 10 mg cohort withdrew consent and quitted the study. No serious adverse event was reported. All treatment-emergent adverse events (TEAEs) were mild or moderate in severity and most commonly-reported TEAEs were upper respiratory tract infection, diarrhoea, decreased appetite, nausea, urinary tract infection, abdominal distension and vomiting. The mean percent change from baseline to week 12 in body weight were -11.7% (SE 1.5) for participants receiving mazdutide in the 9 mg cohort and -1.8% (1.6) for participants receiving placebo (estimated treatment difference [ETD]: -9.8%; 95% confidence interval [CI]: -14.4, -5.3; P = 0.0002). The mean percent change from baseline to week 16 in body weight were -9.5% (SE 1.7) for participants receiving mazdutide in the 10 mg cohort and -3.3% (1.9) for participants receiving placebo (ETD: -6.2%; 95% CI: -11.5, -0.9; P = 0.024). In addition, compared with placebo, mazdutide achieved more profound reductions in waist circumference and BMI.

Interpretation

Mazdutide dosed up to 9 mg and 10 mg was both well tolerated and showed a favourable safety profile. High-dose mazdutide showed promising 12-week body weight loss, holding great potential for the treatment of moderate-to-severe obesity. A larger and longer phase 2 trial will further evaluate the efficacy and safety of high-dose mazdutide in Chinese adults with obesity.

Funding

Innovent Biologics, Inc.

Glucagon receptor antagonism impairs and glucagon receptor agonism enhances triglycerides metabolism in mice

OBJECTIVE

Treatment with glucagon receptor antagonists (GRAs) reduces blood glucose but causes dyslipidemia and accumulation of fat in the liver. We investigated the acute and chronic effects of glucagon on lipid metabolism in mice.

METHODS

Chronic effects of glucagon receptor signaling on lipid metabolism were studied using oral lipid tolerance tests (OLTTs) in overnight fasted glucagon receptor knockout (Gcgr^-/-) mice, and in C57Bl/6JRj mice treated with a glucagon receptor antibody (GCGR Ab) or a long-acting glucagon analogue (GCGA) for eight weeks. Following treatment, liver tissue was harvested for RNA-sequencing and triglyceride measurements. Acute effects were studied in C57Bl/6JRj mice treated with a GRA or GCGA 1 h or immediately before OLTTs, respectively. Direct effects of glucagon on hepatic lipolysis were studied using isolated perfused mouse liver preparations. To investigate potential effects of GCGA and GRA on gastric emptying, paracetamol was, in separate experiments, administered immediately before OLTTs.

RESULTS

Plasma triglyceride concentrations increased 2-fold in Gcgr^-/- mice compared to their wild-type littermates during the OLTT (P = 0.001). Chronic treatment with GCGR Ab increased, whereas GCGA treatment decreased, plasma triglyceride concentrations during OLTTs (P < 0.05). Genes involved in lipid metabolism were upregulated upon GCGR Ab treatment while GCGA treatment had opposite effects. Acute GRA and GCGA treatment, respectively, increased (P = 0.02) and decreased (P = 0.003) plasma triglyceride concentrations during OLTTs. Glucagon stimulated hepatic lipolysis, evident by an increase in free fatty acid concentrations in the effluent from perfused mouse livers. In line with this, GCGR Ab treatment increased, while GCGA treatment decreased, liver triglyceride concentrations. The effects of glucagon appeared independent of changes in gastric emptying of paracetamol.

CONCLUSIONS

Glucagon receptor signaling regulates triglyceride metabolism, both chronically and acutely, in mice. These data expand glucagon´s biological role and implicate that intact glucagon signaling is important for lipid metabolism. Glucagon agonism may have beneficial effects on hepatic and peripheral triglyceride metabolism.

Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone Peptide-Derived G Protein Coupled Receptor Agonists

The increasing prevalence of obesity and type 2 diabetes (T2DM) is provoking an important socioeconomic burden mainly in the form of cardiovascular disease (CVD). One successful strategy is the so-called metabolic surgery whose beneficial effects are beyond dietary restrictions and weight loss. One key underlying mechanism behind this surgery is the cooperative improved action of the preproglucagon-derived hormones, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) which exert their functions through G protein-coupled receptors (GPCR). Great success has been reached with therapies based on the GLP-1 receptor monoagonism; therefore, a logical and rational approach is the use of the dual and triagonism of GCPC to achieve complete metabolic homeostasis. The present review describes novel findings regarding the complex biology of the preproglucagon-derived hormones, their signaling, and the drug development of their analogues, especially those acting as dual and triagonists. Moreover, the main investigations into animal models and ongoing clinical trials using these unimolecular dual and triagonists are included which have demonstrated their safety, efficacy, and beneficial effects on the CV system. These therapeutic strategies could greatly impact the treatment of CVD with unprecedented benefits which will be revealed in the next years.

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.

Signaling pathways in obesity: mechanisms and therapeutic interventions

Obesity is a complex, chronic disease and global public health challenge. Characterized by excessive fat accumulation in the body, obesity sharply increases the risk of several diseases, such as type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease, and is linked to lower life expectancy. Although lifestyle intervention (diet and exercise) has remarkable effects on weight management, achieving long-term success at weight loss is extremely challenging, and the prevalence of obesity continues to rise worldwide. Over the past decades, the pathophysiology of obesity has been extensively investigated, and an increasing number of signal transduction pathways have been implicated in obesity, making it possible to fight obesity in a more effective and precise way. In this review, we summarize recent advances in the pathogenesis of obesity from both experimental and clinical studies, focusing on signaling pathways and their roles in the regulation of food intake, glucose homeostasis, adipogenesis, thermogenesis, and chronic inflammation. We also discuss the current anti-obesity drugs, as well as weight loss compounds in clinical trials, that target these signals. The evolving knowledge of signaling transduction may shed light on the future direction of obesity research, as we move into a new era of precision medicine.

Targeted therapeutics and novel signaling pathways in non-alcohol-associated fatty liver/steatohepatitis (NAFL/NASH)

Non-alcohol-associated fatty liver/steatohepatitis (NAFL/NASH) has become the leading cause of liver disease worldwide. NASH, an advanced form of NAFL, can be progressive and more susceptible to developing cirrhosis and hepatocellular carcinoma. Currently, lifestyle interventions are the most essential and effective strategies for preventing and controlling NAFL without the development of fibrosis. While there are still limited appropriate drugs specifically to treat NAFL/NASH, growing progress is being seen in elucidating the pathogenesis and identifying therapeutic targets. In this review, we discussed recent developments in etiology and prospective therapeutic targets, as well as pharmacological candidates in pre/clinical trials and patents, with a focus on diabetes, hepatic lipid metabolism, inflammation, and fibrosis. Importantly, growing evidence elucidates that the disruption of the gut-liver axis and microbe-derived metabolites drive the pathogenesis of NAFL/NASH. Extracellular vesicles (EVs) act as a signaling mediator, resulting in lipid accumulation, macrophage and hepatic stellate cell activation, further promoting inflammation and liver fibrosis progression during the development of NAFL/NASH. Targeting gut microbiota or EVs may serve as new strategies for the treatment of NAFL/NASH. Finally, other mechanisms, such as cell therapy and genetic approaches, also have enormous therapeutic potential. Incorporating drugs with different mechanisms and personalized medicine may improve the efficacy to better benefit patients with NAFL/NASH.

A phase 1b randomised controlled trial of a glucagon-like peptide-1 and glucagon receptor dual agonist IBI362 (LY3305677) in Chinese patients with type 2 diabetes

The success of glucagon-like peptide-1 (GLP-1) receptor agonists to treat type 2 diabetes (T2D) and obesity has sparked considerable efforts to develop next-generation co-agonists that are more effective. We conducted a randomised, placebo-controlled phase 1b study (ClinicalTrials.gov: NCT04466904) to evaluate the safety and efficacy of IBI362 (LY3305677), a GLP-1 and glucagon receptor dual agonist, in Chinese patients with T2D. A total of 43 patients with T2D were enrolled in three cohorts in nine study centres in China and randomised in each cohort to receive once-weekly IBI362 (3.0 mg, 4.5 mg or 6.0 mg), placebo or open-label dulaglutide (1.5 mg) subcutaneously for 12 weeks. Forty-two patients received the study treatment and were included in the analysis, with eight receiving IBI362, four receiving placebo and two receiving dulaglutide in each cohort. The patients, investigators and study site personnel involved in treating and assessing patients in each cohort were masked to IBI362 and placebo allocation. Primary outcomes were safety and tolerability of IBI362. Secondary outcomes included the change in glycated haemoglobin A_1c (HbA_1c), fasting plasma glucose (FPG) and post-mixed-meal tolerance test (post-MTT) glucose levels. IBI362 was well tolerated. Most commonly-reported treatment-emergent adverse events were diarrhoea (29.2% for IBI362, 33.3% for dulaglutide, 0% for placebo), decreased appetite (25.0% for IBI362, 16.7% for dulaglutide, 0% for placebo) and nausea (16.7% for IBI362, 16.7% for dulaglutide and 8.3% for placebo). HbA_1c, FPG and post-MTT glucose levels were reduced from baseline to week 12 in patients receiving IBI362 in all three cohorts. IBI362 showed a favourable safety profile and clinically meaningful reductions in blood glucose in Chinese patients with T2D.

Glucagon-like peptide-1 receptor (GLP1R) agonists are used to treat type 2 diabetes (T2D), and polyagonists targeting multiple hormone receptors are investigated as potential therapeutics for T2D. Here the authors report that IBI362 (LY3305677), a balanced once-weekly GLP-1 and glucagon receptor dual agonist, showed favourable safety and tolerability in Chinese patients with type 2 diabetes in a randomized controlled phase 1b clinical trial.

GLP-1/GIP/glucagon receptor triagonism gets its try in humans

In this issue, Bossart et al. report the in vivo receptor occupancy, body weight lowering effects in monkeys, and first-in-human results of SAR441255, a balanced GLP-1R/GIPR/GcgR triagonist. Following single doses to humans, SAR441255 shows positive acute glucoregulatory effects and an acceptable safety profile on gastrointestinal tolerability and cardiovascular hemodynamics.

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.

GLP-1 physiology informs the pharmacotherapy of obesity

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP1RA) augment glucose-dependent insulin release and reduce glucagon secretion and gastric emptying, enabling their successful development for the treatment of type 2 diabetes (T2D). These agents also inhibit food intake and reduce body weight, fostering investigation of GLP1RA for the treatment of obesity.

SCOPE OF REVIEW

Here I discuss the physiology of Glucagon-like peptide-1 (GLP-1) action in the control of food intake in animals and humans, highlighting the importance of gut vs. brain-derived GLP-1 for the control of feeding and body weight. The widespread distribution and function of multiple GLP-1 receptor (GLP1R) populations in the central and autonomic nervous system are outlined, and the importance of pathways controlling energy expenditure in preclinical studies vs. reduction of food intake in both animals and humans is highlighted. The relative contributions of vagal afferent pathways vs. GLP1R+ populations in the central nervous system for the physiological reduction of food intake and the anorectic response to GLP1RA are compared and reviewed. Key data enabling the development of two GLP1RA for obesity therapy (liraglutide 3 mg daily and semaglutide 2.4 mg once weekly) are discussed. Finally, emerging data potentially supporting the combination of GLP-1 with additional peptide epitopes in unimolecular multi-agonists, as well as in fixed-dose combination therapies, are highlighted.

MAJOR CONCLUSIONS

The actions of GLP-1 to reduce food intake and body weight are highly conserved in obese animals and humans, in both adolescents and adults. The well-defined mechanisms of GLP-1 action through a single G protein-coupled receptor, together with the extensive safety database of GLP1RA in people with T2D, provide reassurance surrounding the long-term use of these agents in people with obesity and multiple co-morbidities. GLP1RA may also be effective in conditions associated with obesity, such as cardiovascular disease and non-alcoholic steatohepatitis (NASH). Progressive improvements in the efficacy of GLP1RA suggest that GLP-1-based therapies may soon rival bariatric surgery as viable options for the treatment of obesity and its complications.

Striking the Balance: GLP-1/Glucagon Co-Agonism as a Treatment Strategy for Obesity

Obesity and Type 2 diabetes represent global health challenges, and there is an unmet need for long-lasting and effective pharmacotherapies. Although long-acting glucagon-like peptide-1 (GLP-1) analogues are now in routine use for diabetes and are now being utilised for obesity per se, the need for ever better treatments has driven the development of co-agonists, with the theoretical advantages of improved efficacy by targeting multiple pathways and reduced adverse effects. In this review, we highlight the past and present progress in our understanding and development of treatments based on GLP-1/glucagon co-agonism. We also reflect on the divergent effects of varying the GLP-1:glucagon activity and ratio in the context of pre-clinical and human clinical trial findings. In particular, the multiple metabolic actions of glucagon highlight the importance of understanding the contributions of individual hormone action to inform the safe, effective and tailored use of GLP-1/glucagon co-agonists to target weight loss and metabolic disease in the future.

IBI362 (LY3305677), a weekly-dose GLP-1 and glucagon receptor dual agonist, in Chinese adults with overweight or obesity: A randomised, placebo-controlled, multiple ascending dose phase 1b study

BACKGROUND

IBI362 (LY3305677) is a novel weekly-dose glucagon-like peptide-1 and glucagon receptor dual agonist being developed for the treatment of obesity and type 2 diabetes. The aim of this randomised, placebo-controlled, multiple ascending dose phase 1b study was to evaluate the safety, tolerability, pharmacokinetics and efficacy of IBI362 in Chinese adults with overweight or obesity.

METHODS

This study enrolled adults with overweight (body mass index [BMI]≥24 kg/m²) accompanied by hyperphagia and/or at least one comorbidity or obesity (BMI≥28 kg/m²) from six study centres in China. Eligible participants were randomised 2:1 to receive once-weekly subcutaneous injection of IBI362 or placebo in each of the three ascending dose cohorts for 12 weeks with additional 8 weeks of safety follow-up. The dose-escalation regimens were: 3.0 mg cohort (1.0 mg weeks 1-4; 2.0 mg weeks 5-8; 3.0 mg weeks 9-12); 4.5 mg cohort (1.5 mg weeks 1-4; 3.0 mg weeks 5-8; 4.5 mg weeks 9-12); 6.0 mg cohort (2.0 mg weeks 1-4; 4.0 mg weeks 5-8; 6.0 mg weeks 9-12). The participants, investigators and study site personnel involved in treating and assessing participants within each cohort were masked to treatment allocation. The primary endpoints were safety and tolerability of IBI362. This study is registered with ClinicalTrials.gov, number NCT04440345.

FINDINGS

Between June 15^th, 2020 and January 15^th, 2021, 12 participants were enrolled and randomised in each cohort. Throughout the study, no participant discontinued the treatment due to safety reason and no serious adverse event was reported. Gastrointestinal adverse events and decreased appetite were the most common adverse events and mostly mild in severity. Three participants receiving IBI362 reported mild and asymptomatic cardiac disorders revealed by electrocardiogram. Estimated percent changes in mean body weight from baseline to week 12 were -4.81% (95%CI -6.61 to -3.02), -6.40% (-8.23 to -4.58) and -6.05% (-7.91 to -4.18) for participants receiving IBI362 in the 3.0 mg, 4.5 mg and 6.0 mg cohort, respectively, compared with 0.60% (-0.86 to 2.07) for those receiving placebo.

INTERPRETATION

IBI362 was well tolerated and showed a body weight-lowering effect in Chinese adults with overweight or obesity.

FUNDING

Innovent Biologics.