Tirzepatide: A novel, first-in-class, dual GIP/GLP-1 receptor agonist

Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs in Patients with Type 2 Diabetes Treated with Basal Insulin: A Network Meta-analysis

INTRODUCTION

The relative efficacy and safety of tirzepatide was compared with glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes mellitus (T2DM) treated with basal insulin using a network meta-analysis (NMA).

METHODS

A systematic literature review was performed to identify randomized controlled trials of GLP-1 RAs in patients with T2DM treated with insulin and an antihyperglycaemic drug. For the NMA, studies included trials with 100% of patients treated with basal insulin background therapy with a titration scheme comparable to the SURPASS-5 trial. The following data were extracted for efficacy and safety assessment at the primary endpoint of each study: changes from baseline in glycated haemoglobin (HbA1c) and body weight and the incidence of nausea, vomiting or diarrhoea, hypoglycaemia, and patients discontinuing treatment because of adverse events. In this study, a comparative analysis of tirzepatide was performed with the GLP-1 RAs dulaglutide, exenatide, and lixisenatide in addition to placebo.

RESULTS

A total of six studies were included across the analyses. Tirzepatide 5, 10, and 15 mg showed statistically significant, greater reductions in HbA1c and body weight at the primary endpoint versus all GLP-1 RA comparators and placebo. Tirzepatide 5, 10, and 15 mg showed a statistically significant, higher likelihood of experiencing nausea compared with those who received placebo or exenatide 2 mg; no statistically significant differences were observed when compared with all other GLP-1 RA comparators. No statistically significant differences were observed in the proportions of patients who discontinued treatment because of adverse events when tirzepatide 5, 10, and 15 mg were compared with GLP-1 RA comparators, apart from tirzepatide 10 and 15 mg versus placebo.

CONCLUSION

Tirzepatide demonstrated statistically significantly greater reductions in HbA1c and body weight when compared with selected GLP-1 RAs and placebo in patients with T2DM treated with basal insulin. Overall, the safety profile of tirzepatide was similar to that of GLP-1RAs.

Semaglutide as a GLP-1 Agonist: A Breakthrough in Obesity Treatment

This review addresses the role of semaglutide (SMG), a GLP-1 receptor agonist, in the treatment of obesity and its related comorbidities. Originally developed for type 2 diabetes (DM2), SMG has shown significant efficacy in weight reduction, with superior results compared to other treatments in the same class. Its effects include appetite suppression, increased satiety, and improvements in cardiovascular, renal, and metabolic parameters. Studies such as SUSTAIN, PIONEER, and STEP highlight its superiority compared to other GLP-1 receptor agonists and anti-obesity drugs. The oral formulation showed promising initial results, with higher doses (50 mg) showing weight losses comparable to those of subcutaneous administration. Despite its benefits, there are challenges, such as weight regain after cessation of treatment, gastrointestinal adverse effects, and variability of response. Future studies should explore strategies to mitigate these effects, identify predictive factors of efficacy, and expand therapeutic indications to other conditions related to obesity and insulin resistance. The constant innovation in this class of drugs reinforces the potential of SMG to transform treatment protocols for chronic weight-related diseases.

Gastrointestinal safety of semaglutide and tirzepatide vs. placebo in obese individuals without diabetes: a systematic review and meta analysis

INTRODUCTION

Semaglutide and tirzepatide are newly approved glucagon-like peptide-1 receptor agonists for weight management in adults without diabetes. However, safety concerns regarding gastrointestinal (GI) adverse outcomes have been raised. This review comprehensively evaluates their GI safety profile in randomized controlled trials (RCTs).

METHODS

Thirteen RCTs involving 26 894 obese participants without diabetes were analyzed. Pooled analysis assessed the risks for GI, biliary, hepatic, and pancreatic adverse events.

RESULTS

Overall GI adverse events were 1.86 times higher with *both* agents (95% CI=1.56, 2.21), with tirzepatide showing a greater risk (RR 2.94, 95% CI=2.61, 3.32) than semaglutide (RR 1.68, 95% CI=1.46, 1.94). Semaglutide increased gallbladder-related disorders, particularly cholelithiasis, by over 2.6 times (95% CI=1.40, 4.82), while tirzepatide showed no significant biliary risk. Neither agent significantly increased hepatic or pancreatic adverse events.

CONCLUSION

Compared to placebo, both Semaglutide and tirzepatide are associated with increased GI adverse outcomes, with most cases being mild. Clinicians should carefully monitor patients for potential adverse outcomes.

Renal effects and safety of tirzepatide in subjects with and without diabetes: A systematic review and meta-analysis

BACKGROUND

Type 2 diabetes (T2D), as well as obesity, are risk factors for chronic kidney disease (CKD) and end-stage renal disease. The renal impacts of glucose-lowering and weight-lowering drugs and their potential benefits in preventing CKD often guide clinicians in choosing them appropriately. Only limited data based on randomized controlled trials (RCTs) is currently available on the renal effects and safety profile of tirzepatide.

AIM

To explore the renal benefits and safety of tirzepatide vs controls.

METHODS

RCTs involving patients receiving tirzepatide for any indication in the intervention arm and placebo or active comparator in the control arm were searched through multiple electronic databases. The co-primary outcomes were percent change from baseline (CFB) in urine albumin-to-creatinine ratio (UACR) and absolute CFB in estimated glomerular filtration rate (eGFR; in mL/min/1.73 m2); the secondary outcome was tirzepatide's renal safety profile. RevMan web was used to conduct meta-analysis using random-effects models. Outcomes were presented as mean differences (MD) or risk ratios with 95% confidence intervals.

RESULTS

Fifteen RCTs (n = 14471) with mostly low risk of bias (RoB) were included. Over 26-72 weeks, tirzepatide 10 mg [MD -26.95% (-40.13, -13.76), P < 0.0001] and 15 mg [MD -18.03% (-28.58, -7.47), P = 0.0008] were superior to placebo in percent reductions of UACR. Tirzepatide, at all doses, outperformed insulin in percent reductions of UACR. Compared to the placebo, the percent UACR reduction was greater in subjects with T2D than those with obesity but without T2D (MD -33.25% vs -7.93%; P = 0.001). The CFB in eGFR with all doses of tirzepatide was comparable [5 mg: MD 0.36 (-1.41, 2.14); 10 mg: MD 1.17 (-0.22, 2.56); 15 mg: MD 1.42 (-0.04, 2.88)]; P > 0.05 for all] vs insulin. Tirzepatide (pooled and separate doses) did not increase the risks of adverse renal events, urinary tract infection, nephrolithiasis, acute kidney injury, and renal cancer compared to the placebo, insulin, and glucagon-like peptide-1 receptor agonists.

CONCLUSION

Short-term data from RCTs with low RoB suggests that tirzepatide positively impacts UACR without detrimental effects on eGFR in subjects with T2D and obesity without T2D, with a reassuring renal safety profile. Larger RCTs are warranted to prove the longer-term renal benefits of tirzepatide, which might also prevent eGFR decline and worsening of CKD.

Endogenous Glucagon-Like Peptide-1 Receptor and Glucose-Dependent Insulinotropic Polypeptide Receptor Signaling Inhibits Aeroallergen-Induced Innate Airway Inflammation

BACKGROUND

Anti-inflammatory effects of incretin signaling through the glucagon-like peptide-1 receptor (GLP-1R) and the glucose-dependent insulinotropic polypeptide receptor (GIPR) in mice have been reported. Therefore, we hypothesized that signaling through the endogenous GLP-1R and the GIPR individually decreases allergic airway inflammation and that the combination of GLP-1R and GIPR signaling together additively inhibits allergen-induced lung and airway inflammation.

METHODS

WT (C57BL/6J), GLP-1R knockout (KO), GIPR KO, and GLP-1R/GIPR double KO (DKO) mice were challenged intranasally with Alternaria alternata extract (Alt-Ext) or vehicle to evaluate the impact of signaling through these receptors on the innate allergen-induced inflammatory response that is primarily driven by group 2 innate lymphoid cells (ILC2).

RESULTS

Alt-Ext-induced IL-33 release in the bronchoalveolar lavage fluid (BALF) was not different between the mouse strains, but thymic stromal lymphopoietin (TSLP) was significantly increased in GLP-1R/GIPR DKO mice challenged with Alt-Ext compared to the other strains. Furthermore, Alt-Ext-induced protein expression of IL-5, IL-13, CCL11, and CCL24 in the lung homogenates, the number of eosinophils, lymphocytes, and neutrophils in the BALF, and the number of lung GATA3+ ILC2 were significantly increased in GLP-1R/GIPR DKO mice compared to the other 3 strains. Furthermore, ICAM-1 expression on lung epithelial cells was increased in GLP-1R/GIPR DKO mice challenged with Alt-Ext compared to the other 3 strains.

CONCLUSIONS

Deficiency of both GLP-1R and GIPR signaling together increased TSLP release, ILC2 activation, and early type 2 innate immune responses to aeroallergen exposure. Combined GLP-1R and GIPR signaling should be explored for the treatment of asthma.

Advances in the Insulin-Heart Axis: Current Therapies and Future Directions

The insulin-heart axis plays a pivotal role in the pathophysiology of cardiovascular disease (CVD) in insulin-resistant states, including type 2 diabetes mellitus. Insulin resistance disrupts glucose and lipid metabolism, leading to systemic inflammation, oxidative stress, and atherogenesis, which contribute to heart failure (HF) and other CVDs. This review was conducted by systematically searching PubMed, Scopus, and Web of Science databases for peer-reviewed studies published in the past decade, focusing on therapeutic interventions targeting the insulin-heart axis. Studies were selected based on their relevance to insulin resistance, cardiovascular outcomes, and the efficacy of pharmacologic treatments. Key findings from the review highlight the efficacy of lifestyle modifications, such as dietary changes and physical activity, which remain the cornerstone of managing insulin resistance and improving cardiovascular outcomes. Moreover, pharmacologic interventions, such as metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors, have shown efficacy in reducing cardiovascular risk by addressing metabolic dysfunction, reducing inflammation, and improving endothelial function. Furthermore, emerging treatments, such as angiotensin receptor-neprilysin inhibitors, and mechanical interventions like ventricular assist devices offer new avenues for managing HF in insulin-resistant patients. The potential of these therapies to improve left ventricular ejection fraction and reverse pathological cardiac remodeling highlights the importance of early intervention. However, challenges remain in optimizing treatment regimens and understanding the long-term cardiovascular effects of these agents. Future research should focus on personalized approaches that integrate lifestyle and pharmacologic therapies to effectively target the insulin-heart axis and mitigate the burden of cardiovascular complications in insulin-resistant populations.

Tirzepatide against obesity and insulin-resistance: pathophysiological aspects and clinical evidence

Obesity is a chronic, multifactorial disease in which accumulated excess body fat has a negative impact on health. Obesity continues to rise among the general population, resulting in an epidemic that shows no significant signs of decline. It is directly involved in development of cardiometabolic diseases, ischemic coronary heart disease peripheral arterial disease, heart failure, and arterial hypertension, producing global morbidity and mortality. Mainly, abdominal obesity represents a crucial factor for cardiovascular illness and also the most frequent component of metabolic syndrome. Recent evidence showed that Tirzepatide (TZP), a new drug including both Glucagon Like Peptide 1 (GLP-1) and Glucose-dependent Insulinotropic Polypeptide (GIP) receptor agonism, is effective in subjects with type 2 diabetes (T2D), lowering body weight, fat mass and glycated hemoglobin (HbA1c) also in obese or overweight adults without T2D. This review discusses the pathophysiological mechanisms and clinical aspects of TZP in treating obesity.

Treatment Options and Continuity of Care in Metabolic-associated Fatty Liver Disease: A Multidisciplinary Approach

The terms non-alcoholic fatty liver disease and non-alcoholic steatohepatitis have some limitations as they use exclusionary confounder terms and the use of potentially stigmatising language. Recently, a study with content experts and patients has been set to change this nomenclature. The term chosen to replace non-alcoholic fatty liver disease was metabolic dysfunction-associated steatotic liver disease (MASLD), which avoids stigmatising and helps improve awareness and patient identification. MASLD is the most common cause of chronic liver disease with an increasing prevalence, accounting for 25% of the global population. It is considered the hepatic manifestation of the metabolic syndrome with lifestyle playing a fundamental role in its physiopathology. Diet change and physical activity are the cornerstones of treatment, encompassing weight loss and healthier behaviours and a holistic approach. In Europe, there is no approved drug for MASLD to date and there is a substantial unmet medical need for effective treatments for patients with MASLD. This review not only provides an update on advances in evidence for nutrition and physical activity interventions but also explores the different therapeutic options that are being investigated and whose development focuses on the restitution of metabolic derangements and halting inflammatory and fibrogenic pathways.

US Population Eligibility and Estimated Impact of Tirzepatide Treatment on Obesity Prevalence and Cardiovascular Disease Events

PURPOSE

Tirzepatide promotes weight loss and reduces risk factors for cardiovascular disease (CVD) in adults with overweight and obesity. We examined the number of US adults eligible for tirzepatide and its impact on obesity and CVD events.

METHODS

We identified US adults aged ≥ 18 years from the cross-sectional US National Health and Nutrition Examination Survey (NHANES) 2015-2018 eligible for tirzepatide based on SURMOUNT-1 trial eligibility criteria. Weight changes in SURMOUNT-1 from tirzepatide 15 mg treatment were used to project the impact on weight change and obesity prevalence in the population assuming titration to this dosage. We estimated 10-year CVD risks from BMI-based Framingham CVD risk scores before and after applying tirzepatide 15 mg treatment BMI and risk factor effects from SURMOUNT-1, the differences in estimated risks multiplied by the eligible NHANES weighted population representing the estimated "preventable" CVD events.

RESULTS

We identified 4015 US adults (estimated population size of 93.4 million [M]) to fit SURMOUNT-1 eligibility criteria, representing 38% of US adults. When the effects of 15 mg tirzepatide were applied, we estimated 70.6% (65.9 M) and 56.7% (53.0 M) of adults to show ≥ 15% and ≥ 20% reductions in weight, respectively, translating to 58.8% (55.0 M) fewer persons with obesity. Among those without CVD, estimated 10-year CVD risks were 10.1% "before" and 7.7% "after" tirzepatide "treatment" reflecting a 2.4% absolute (and 23.6% relative) risk reduction translating to 2.0 million preventable CVD events over 10 years.

CONCLUSION

Tirzepatide treatment in appropriate US adults may substantially reduce obesity prevalence and CVD events, impacting beneficially on associated healthcare costs.

New Molecules in Type 2 Diabetes: Advancements, Challenges and Future Directions

Although good glycemic control in patients with type 2 diabetes (T2D) can prevent cardiovascular complications, many diabetic patients still have poor optimal control. A new class of antidiabetic drugs (e.g., glucagon-like peptide-1-GLP-1 receptor agonists, sodium-glucose co-transporters-SGLT2 inhibitors), in addition to the low hypoglycemic effect, exert multiple beneficial effects at a metabolic and cardiovascular level, through mechanisms other than antihyperglycemic agents. This review aims to discuss the effects of these new antidiabetic drugs, highlighting cardiovascular and metabolic benefits, through the description of their action mechanisms as well as available data by preclinical and clinical studies. Moreover, new innovative tools in the T2D field will be described which may help to advance towards a better targeted T2D personalized care in future.

Glucagon-like peptide-1 analogs: Miracle drugs are blooming?

Glucagon-like peptide-1 (GLP-1), secreted by L cells in the small intestine, assumes a central role in managing type 2 diabetes mellitus (T2DM) and obesity. Its influence on insulin secretion and gastric emptying positions it as a therapeutic linchpin. However, the limited applicability of native GLP-1 stems from its short half-life, primarily due to glomerular filtration and the inactivating effect of dipeptidyl peptidase-IV (DPP-IV). To address this, various structural modification strategies have been developed to extend GLP-1's half-life. Despite the commendable efficacy displayed by current GLP-1 receptor agonists, inherent limitations persist. A paradigm shift emerges with the advent of unimolecular multi-agonists, such as the recently introduced tirzepatide, wherein GLP-1 is ingeniously combined with other gastrointestinal hormones. This novel approach has captured the spotlight within the diabetes and obesity research community. This review summarizes the physiological functions of GLP-1, systematically explores diverse structural modifications, delves into the realm of unimolecular multi-agonists, and provides a nuanced portrayal of the developmental prospects that lie ahead for GLP-1 analogs.

The effects of subcutaneous Tirzepatide on obesity and overweight: a systematic review and meta-regression analysis of randomized controlled trials

Background

Despite the fact that obesity and overweight are serious major health problems worldwide, fighting against them is also considered a challenging issue. Several interventional studies have evaluated the potential weight-reduction effect of Tirzepatide. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of subcutaneous Tirzepatide on obesity and overweight.

Methods

Scopus, PubMed/Medline, Web of Science, Cochrane, and Embase databases were searched using standard keywords to identify all controlled trials investigating the weight loss effects of Tirzepatide. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model analysis for the best estimation of outcomes. The statistical heterogeneity and publication bias were determined using the Cochran's Q test and I2 statistics and using the funnel plot and Egger's test, respectively.

Results

Twenty three treatments arm with 7062 participants' were included in this systematic review and meta-regression analysis. The pooled findings showed that Tirzepatide vs placebo significantly reduced body weight (weighted mean difference (WMD): -11.34 kg, 95% confidence interval (CI): -12.79 to -9.88, P< 0.001), body mass index (BMI) (WMD: -3.11 kg/m2, 95% CI: -4.36 to -1.86, P< 0.001), and waist circumference (WC) (WMD: -7.24 cm, 95% CI -10.12 to -4.36, P< 0.001). These reductions were even greater, especially with higher doses and duration of Tirzepatide.

Conclusions

Tirzepatide medication had significant effects on weight management with the reduction of body weight, BMI, and WC. Administration of Tirzepatide can be considered a therapeutic strategy for overweight or obese people.

Novel Dual Incretin Receptor Agonists in the Spectrum of Metabolic Diseases with a Focus on Tirzepatide: Real Game-Changers or Great Expectations? A Narrative Review

The prevalence of metabolic diseases including type 2 diabetes (T2D), obesity and non-alcoholic fatty liver disease (NAFLD) increases globally. This highlights an unmet need for identifying optimal therapies for the management of these conditions. Tirzepatide is a novel dual incretin receptor agonist (twincretin) that activates both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors. The aim of this narrative review was to examine the impact of novel twincretins, focusing on tirzepatide, on the management of a wide spectrum of metabolic diseases. Data from preclinical and clinical trials have shown that twincretins significantly reduce blood glucose levels in T2D, and tirzepatide is the first agent of this class that has been approved for the management of T2D. Additionally, the beneficial impact of tirzepatide on weight reduction has been corroborated in several studies, showing that this agent can achieve substantial and sustained weight loss in obese patients with or without T2D. Data also suggest that tirzepatide could be a promising drug for hepatic steatosis reduction in individuals with NAFLD. The remarkable effects of tirzepatide on glycaemic control, weight loss and liver-related outcomes have posed new research questions that are likely to lead to further advancements in the treatment of T2D, obesity and related metabolic disorders.

Current Treatment Options, Including Diet, Exercise, and Medications: The Impact on Histology

Paralleling the rise in obesity and diabetes, nonalcoholic fatty liver disease (NAFLD) is now the most prevalent chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH), the progressive form of NAFLD, may progress to cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Despite its public health treat, no approved pharmacotherapies for NAFLD/NASH currently exist. Although the armamentarium of therapies for NASH is limited, current treatment options include life-style modification and the use of medications to treat metabolic comorbidities. This review addresses current approaches to the treatment of NAFLD/NASH, including the impact of diet, exercise, and available pharmacotherapies on the histologic features of liver injury.