Clinical Potential of GIP in Type 2 Diabetes and Obesity.

Disclosure: I. Davies: None. A. Turland: None. C. Wong: None. H. Tran: None. O. Cahn: None. S.R. Bloom: Zihipp. B. Jones: Metsera, Eli Lilly and Company, Sun Pharma. T. Tan: Zihipp. Introduction: There is significant interest in targeting the glucose dependent insulinotropic polypeptide receptor (GIPR) for the treatment of type 2 diabetes and obesity. However, the optimal method of receptor targeting remains unclear: both activating or inhibiting the GIPR has resulted in metabolic improvement in preclinical models. Moreover, both tirzepatide (a GLP-1R/GIPR dual agonist) and AMG133 (a GLP-1R agonist/ GIPR antagonist) appear to outperform GLP-1R mono-agonists with regards to weight loss in clinical trials. Importantly, there are limited data regarding the comparative metabolic effects of a GIPR agonist versus GIPR antagonist, making valid comparisons between the two pharmacotherapeutic strategies difficult. Aim: Perform an in-depth metabolic comparison of a GIPR agonist (GIP108) versus a GIPR antagonist (NN-GIPR-Ant) in mouse models. Methods: Peptide characterisation was performed in AD293 cells transiently expressing the mouse GIPR, glucagon-like-peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR). cAMP responses using live cell imaging were recorded in mouse pancreatic islets and hypothalamic neurons. Food intake, body weight and blood glucose effects were determined in HFD-induced obese mice. Aversive behaviours were assessed in lean mice. Results: cAMP assessment in GIPR-expressing AD293 cells confirmed the categorisation of GIP108 and NN-GIPR-Ant as a GIPR agonist and antagonist, respectively. Both peptides resulted in minimal cAMP accumulation in cells expressing the mouse GLP-1R or GCGR. GIP108, but not NN-GIPR-Ant, resulted in significant cAMP responses in dispersed mouse pancreatic islets. These findings were mirrored in vivo: while NN-GIPR-Ant displayed no anti-hyperglycaemic efficacy, both single dose and 21-day administration of GIP108 resulted in significant improvements in glucose tolerance in HFD-induced obese mice. We failed to detect a cAMP response in hypothalamic neurons following stimulation with GIP108 or NN-GIPR-Ant, probably due to low GIPR expression. However, acute and chronic administration of GIP108 and NN-GIPR-Ant to HFD-induced obese mice resulted in comparable levels of food intake suppression and body weight reduction. Neither peptide was able to prevent semaglutide-induced aversive behaviours in mice. Conclusion: These results highlight that while both GIPR activation and inhibition result in appetite and body weight reduction, only GIPR activation can significantly improve glucose tolerance - a finding of relevance in the development of GIPR-targeting metabolic therapeutics. Moreover, the observation that GIP108 was unable to prevent GLP-1RA induced emesis, an effect induced by other GIPR agonists, highlights the heterogeneity in CNS responses induced by different GIPR agonists. A comparison of the metabolic effectiveness of both approaches in humans is an important area of future study. Presentation: Sunday, July 13, 2025

<p dir="ltr">Incretin-based pharmacology has revolutionized the medical treatment of type 2 diabetes and obesity. The most effective drug to date is tirzepatide, a dual incretin receptor agonist that engages both the glucagon-like peptide-1 receptor (GLP-1R) and the glucose-dependent insulinotropic polypeptide receptor (GIPR). While the relative contributions of GIPR and GLP-1R actions to the clinical effects of tirzepatide have not been established, the potency of this agent has reignited interest in the clinical potential of GIPR agonism. Here, we discuss incretin biology as it relates to metabolic pharmacology and contextualize the mechanisms by which GIPR activity could contribute to the development of new and effective drugs. We explore current and future applications of GIPR agonists and antagonists, to underscore the potential that this signaling system could add to treatment of type 2 diabetes and obesity.</p>

<p dir="ltr">Incretin-based pharmacology has revolutionized the medical treatment of type 2 diabetes and obesity. The most effective drug to date is tirzepatide, a dual incretin receptor agonist that engages both the glucagon-like peptide-1 receptor (GLP-1R) and the glucose-dependent insulinotropic polypeptide receptor (GIPR). While the relative contributions of GIPR and GLP-1R actions to the clinical effects of tirzepatide have not been established, the potency of this agent has reignited interest in the clinical potential of GIPR agonism. Here, we discuss incretin biology as it relates to metabolic pharmacology and contextualize the mechanisms by which GIPR activity could contribute to the development of new and effective drugs. We explore current and future applications of GIPR agonists and antagonists, to underscore the potential that this signaling system could add to treatment of type 2 diabetes and obesity.</p>

Antagonism or agonism of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) prevents weight gain and leads to dramatic weight loss in combination with glucagon-like peptide-1 receptor agonists in preclinical models. Based on the genetic evidence supporting GIPR antagonism, we previously developed a mouse anti-murine GIPR antibody (muGIPR-Ab) that protected diet-induced obese (DIO) mice against body weight gain and improved multiple metabolic parameters. This work reconciles the similar preclinical body weight effects of GIPR antagonists and agonists in vivo, and here we show that chronic GIPR agonism desensitizes GIPR activity in primary adipocytes, both differentiated in vitro and adipose tissue in vivo, and functions like a GIPR antagonist. Additionally, GIPR activity in adipocytes is partially responsible for muGIPR-Ab to prevent weight gain in DIO mice, demonstrating a role of adipocyte GIPR in the regulation of adiposity in vivo.

Efficacy and safety of LY3298176, a novel dual GIP and GLP-1 receptor agonist, in patients with type 2 diabetes: a randomised, placebo-controlled and active comparator-controlled phase 2 trial

Recent approval of the dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, tirzepatide, for the management of type 2 diabetes mellitus (T2DM) has reinvigorated interest in exploitation of GIP receptor (GIPR) pathways as a means of metabolic disease management. However, debate has long surrounded the use of the GIPR as a therapeutic target and whether agonism or antagonism is of most benefit in management of obesity/diabetes. This controversy appears to be partly resolved by the success of tirzepatide. However, emerging studies indicate that prolonged GIPR agonism may desensitise the GIPR to essentially induce receptor antagonism, with this phenomenon suggested to be more pronounced in the human than rodent setting. Thus, deliberation continues to rage in relation to benefits of GIPR agonism vs antagonism. That said, as with GIPR agonism, it is clear that the metabolic advantages of sustained GIPR antagonism in obesity and obesity-driven forms of diabetes can be enhanced by concurrent GLP-1 receptor (GLP-1R) activation. This narrative review discusses various approaches of pharmacological GIPR antagonism including small molecule, peptide, monoclonal antibody and peptide-antibody conjugates, indicating stage of development and significance to the field. Taken together, there is little doubt that interesting times lie ahead for GIPR agonism and antagonism, either alone or when combined with GLP-1R agonists, as a therapeutic intervention for the management of obesity and associated metabolic disease.

The GIP receptor activates futile calcium cycling in white adipose tissue to increase energy expenditure and drive weight loss in mice.

Agonists and antagonists of the glucose-dependent insulinotropic polypeptide receptor (GIPR) enhance body weight loss induced by glucagon-like peptide-1 receptor (GLP-1R) agonism. However, while GIPR agonism decreases body weight and food intake in a GLP-1R-independent manner via GABAergic GIPR+ neurons, it remains unclear whether GIPR antagonism affects energy metabolism via a similar mechanism. Here we show that the body weight and food intake effects of GIPR antagonism are eliminated in mice with global loss of either Gipr or Glp-1r but are preserved in mice with loss of Gipr in either GABAergic neurons of the central nervous system or peripherin-expressing neurons of the peripheral nervous system. Single-nucleus RNA-sequencing shows opposing effects of GIPR agonism and antagonism in the dorsal vagal complex, with antagonism, but not agonism, closely resembling GLP-1R signalling. Additionally, GIPR antagonism and GLP-1R agonism both regulate genes implicated in synaptic plasticity. Collectively, we show that GIPR agonism and antagonism decrease body weight via different mechanisms, with GIPR antagonism, unlike agonism, depending on functional GLP-1R signalling.

IntroductionDue to reports of severely reduced insulinotropic effect of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) in type 2 diabetes (T2D), GIP has not been considered therapeutically viable. Recently, however,...

Glucose-dependent insulinotropic polypeptide (GIP) receptor antagonists as anti-diabetic agents

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

The approvals of semaglutide and tirzepatide have set new benchmarks in the treatment of type 2 diabetes and obesity. Building on their success, novel glucagon-like peptide-1 (GLP-1)-based therapeutics are rapidly advancing. These next-generation agents engage not only GLP-1 receptors but also those for other gastro-entero-pancreatic hormones such as glucose-dependent insulinotropic polypeptide (GIP), glucagon, amylin, and peptide YY to enhance energy uptake, storage, and expenditure through synergistic mechanisms. Both GIP receptor agonism and antagonism, particularly in combination with GLP-1 receptor agonism, have shown promise. Maridebart cafraglutide, combining GLP-1 receptor agonism with GIP receptor antagonism, exemplifies this innovative approach. Glucagon coagonists like survodutide and mazdutide have demonstrated significant weight loss and improved glycemic control. Amylin-based agents, including CagriSema (cagrilintide + semaglutide) and amycretin, enhance satiety and glycemic outcomes through complementary actions. Further innovation is seen in triple agonists such as retatrutide, which targets GIP, GLP-1, and glucagon receptors to amplify metabolic effects. Meanwhile, the emergence of orally active small-molecule GLP-1 receptor agonists like danuglipron and orforglipron, which are resistant to enzymatic degradation, marks a major advance in patient-friendly drug delivery. This review explores the mechanisms, clinical development, and therapeutic potential of these novel agents, excluding already approved drugs like liraglutide, semaglutide, and tirzepatide. We highlight how multireceptor agonists and oral GLP-1-based therapies may reshape the future landscape of obesity and type 2 diabetes treatment by offering more effective and better-tolerated options.

Incretin-based therapies are highly successful in combatting obesity and type 2 diabetes1. Yet both activation and inhibition of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) in combination with glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) activation have resulted in similar clinical outcomes, as demonstrated by the GIPR–GLP-1R co-agonist tirzepatide2 and AMG-133 (ref. 3) combining GIPR antagonism with GLP-1R agonism. This underlines the importance of a better understanding of the GIP system. Here we show the necessity of β-arrestin recruitment for GIPR function, by combining in vitro pharmacological characterization of 47 GIPR variants with burden testing of clinical phenotypes and in vivo studies. Burden testing of variants with distinct ligand-binding capacity, Gs activation (cyclic adenosine monophosphate production) and β-arrestin 2 recruitment and internalization shows that unlike variants solely impaired in Gs signalling, variants impaired in both Gs and β-arrestin 2 recruitment contribute to lower adiposity-related traits. Endosomal Gs-mediated signalling of the variants shows a β-arrestin dependency and genetic ablation of β-arrestin 2 impairs cyclic adenosine monophosphate production and decreases GIP efficacy on glucose control in male mice. This study highlights a crucial impact of β-arrestins in regulating GIPR signalling and overall preservation of biological activity that may facilitate new developments in therapeutic targeting of the GIPR system.

Tirzepatide and the new era of twincretins for diabetes

The development of single-molecule co-agonists for the glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) is considered a breakthrough in the treatment of obesity and type 2 diabetes. But although GIPR–GLP-1R co-agonism decreases body weight with superior efficacy relative to GLP-1R agonism alone in preclinical1–3 and clinical studies4,5, the role of GIP in regulating energy metabolism remains enigmatic. Increasing evidence suggests that long-acting GIPR agonists act in the brain to decrease body weight through the inhibition of food intake3,6–8; however, the mechanisms and neuronal populations through which GIP affects metabolism remain to be identified. Here, we report that long-acting GIPR agonists and GIPR–GLP-1R co-agonists decrease body weight and food intake via inhibitory GABAergic neurons. We show that acyl-GIP decreases body weight and food intake in male diet-induced obese wild-type mice, but not in mice with deletion of Gipr in Vgat(also known as Slc32a1)-expressing GABAergic neurons (Vgat-Gipr knockout). Whereas the GIPR–GLP-1R co-agonist MAR709 leads, in male diet-induced obese wild-type mice, to greater weight loss and further inhibition of food intake relative to a pharmacokinetically matched acyl-GLP-1 control, this superiority over GLP-1 vanishes in Vgat-Gipr knockout mice. Our data demonstrate that long-acting GIPR agonists crucially depend on GIPR signaling in inhibitory GABAergic neurons to decrease body weight and food intake.