Fasiglifam for glycaemic control in people with type 2 diabetes: A phase III, placebo-controlled study

Xelaglifam, a novel GPR40/FFAR1 agonist, exhibits enhanced β-arrestin recruitment and sustained glycemic control for type 2 diabetes

Xelaglifam, developed as a GPR40/FFAR1 agonist, induces glucose-dependent insulin secretion and reduces circulating glucose levels for Type 2 diabetes treatment. This study investigated the effects of Xelaglifam in comparison with Fasiglifam on the in vitro/in vivo anti-diabetic efficacy and selectivity, and the mechanistic basis. In vitro studies on downstream targets of Xelaglifam were performed in GPR40-expressing cells. Xelaglifam treatment exhibited dose-dependent effects, increasing inositol phosphate-1, Ca2+ mobilization, and β-arrestin recruitment (EC50: 0.76 nM, 20 nM, 68 nM), supporting its role in Gq protein-dependent and G-protein-independent mechanisms. Despite a lack of change in the cAMP pathway, the Xelaglifam-treated group demonstrated increased insulin secretion compared to Fasiglifam in HIT-T15 β cells under high glucose conditions. High doses of Xelaglifam (<30 mg/kg) did not induce hypoglycemia in Sprague-Dawley rats. In addition, Xelaglifam lowered glucose and increased insulin levels in diabetic rat models (GK, ZDF, OLETF). In GK rats, 1 mg/kg of Xelaglifam improved glucose tolerance (33.4 % and 15.6 % for the 1 and 5 h) after consecutive glucose challenges. Moreover, repeated dosing in ZDF and OLETF rats resulted in superior glucose tolerance (34 % and 35.1 % in ZDF and OLETF), reducing fasting hyperglycemia (18.3 % and 30 % in ZDF and OLETF) at lower doses; Xelaglifam demonstrated a longer-lasting effect with a greater effect on β-cells including 3.8-fold enhanced insulin secretion. Co-treatment of Xelaglifam with SGLT-2 inhibitors showed additive or synergistic effects. Collectively, these results demonstrate the therapeutic efficacy and selectivity of Xelaglifam on GPR40, supportive of its potential for the treatment of Type 2 diabetes.

First-in-human study of CPL207280, a novel G-protein-coupled receptor 40/free fatty acid receptor 1 agonist, in healthy volunteers after single and multiple administration

AIM

To assess the safety, tolerability and pharmacokinetic (PK) profile of single and multiple doses of CPL207280, a new G-protein-coupled receptor 40 agonist developed to treat type 2 diabetes (T2D).

METHODS

The phase 1 study in healthy volunteers (White, age 18-55 years, body mass index 18.5-29.9 kg/m2 ) was performed after single (24 subjects, 5-480 mg) and multiple (32 subjects, 60-480 mg) once-daily administration of CPL207280.  The effect of food intake and interaction with metformin were evaluated in additional cohort (12 subjects, 120 mg). The primary objective was the safety and tolerability of CPL207280. Secondary objectives included PK and pharmacodynamic (PD) characteristics (glucose, insulin, C-peptide, proinsulin, glucagon levels) observed during the 14-day treatment period.

RESULTS

No deaths or serious adverse events (AEs) were reported. All reported AEs were classified as unrelated to the study product. No clinically significant differences in safety parameters were observed between cohorts and no food or metformin effect on safety parameters was identified. The ascending dose of CPL207280 caused an increase in the PK parameters maximum observed plasma concentration (Cmax ) or area under the plasma concentration-time curve up to 24 h. However, dose-normalized Cmax decreased with ascending dose. There was no relationship between the CPL207280 dose or prandial state and terminal elimination half-life and terminal elimination rate constant. No clear relationship between CPL207280 dose and PD area under the effect curve values was observed.

CONCLUSIONS

CPL207280 was found to be safe and well tolerated by healthy volunteers (with a low risk of hepatotoxicity) for up to 14 days of administration. The PK profile of CPL207280 supports single-daily administration and justifies further development of this therapy for patients with T2D.

G Protein-Coupled Receptors and the Rise of Type 2 Diabetes in Children

The human genome counts hundreds of GPCRs specialized to sense thousands of different extracellular cues, including light, odorants and nutrients in addition to hormones. Primordial GPCRs were likely glucose transporters that became sensors to monitor the abundance of nutrients and direct the cell to switch from aerobic metabolism to fermentation. Human β cells express multiple GPCRs that contribute to regulate glucose homeostasis, cooperating with many others expressed by a variety of cell types and tissues. These GPCRs are intensely studied as pharmacological targets to treat type 2 diabetes in adults. The dramatic rise of type 2 diabetes incidence in pediatric age is likely correlated to the rapidly evolving lifestyle of children and adolescents of the new century. Current pharmacological treatments are based on therapies designed for adults, while youth and puberty are characterized by a different hormonal balance related to glucose metabolism. This review focuses on GPCRs functional traits that are relevant for β cells function, with an emphasis on aspects that could help to differentiate new treatments specifically addressed to young type 2 diabetes patients.

Omega-3 pleiad: The multipoint anti-inflammatory strategy

Omega 3 (ω3) fatty acids have been described since the 1980s as promising anti-inflammatory substances. Prostaglandin and leukotriene modulation were exhaustively explored as the main reason for ω3 beneficial outcomes. However, during the early 2000s, after the human genome decoding advent, the nutrigenomic approaches exhibited an impressive plethora of ω3 targets, now under the molecular point of view. Different G protein-coupled receptors (GPCRs) recognizing ω3 and its derivatives appear to be responsible for blocking inflammation and insulin-sensitizing effects. A new class of ω3-derived substances, such as maresins, resolvins, and protectins, increases ω3 actions. Inflammasome disruption, the presence of GPR120 on immune cell surfaces, and intracellular crosstalk signaling mediated by PPARγ compose the last discoveries regarding the multipoint anti-inflammatory targets for this nutrient. This review shows a detailed mechanistic proposal to understand ω3 fatty acid action over the inflammatory environment in the background of several chronic diseases.

Experimental and Emerging Free Fatty Acid Receptor Agonists for the Treatment of Type 2 Diabetes

The current management of Type 2 Diabetes Mellitus (T2DM) includes incretin-based treatments able to enhance insulin secretion and peripheral insulin sensitivity as well as improve body mass, inflammation, plasma lipids, blood pressure, and cardiovascular outcomes. Dietary Free Fatty Acids (FFA) regulate metabolic and anti-inflammatory processes through their action on incretins. Selective synthetic ligands for FFA1-4 receptors have been developed as potential treatments for T2DM. To comprehensively review the available evidence for the potential role of FFA receptor agonists in the treatment of T2DM, we performed an electronic database search assessing the association between FFAs, T2DM, inflammation, and incretins. Evidence indicates that FFA1-4 agonism increases insulin sensitivity, induces body mass loss, reduces inflammation, and has beneficial metabolic effects. There is a strong inter-relationship between FFAs and incretins. FFA receptor agonism represents a potential target for the treatment of T2DM and may provide an avenue for the management of cardiometabolic risk in susceptible individuals. Further research promises to shed more light on this emerging topic.

Recent Updates on Free Fatty Acid Receptor 1 (GPR-40) Agonists for the Treatment of Type 2 Diabetes Mellitus

BACKGROUND

The global incidence of type 2 diabetes mellitus (T2DM) has enthused the development of new antidiabetic targets with low toxicity and long-term stability. In this respect, free fatty acid receptor 1 (FFAR1), which is also recognized as a G protein-coupled receptor 40 (GPR40), is a novel target for the treatment of T2DM. FFAR1/GPR40 has a high level of expression in β-cells of the pancreas, and the requirement of glucose for stimulating insulin release results in immense stimulation to utilise this target in the medication of T2DM.

METHODS

The data used for this review is based on the search of several scienctific databases as well as various patent databases. The main search terms used were free fatty acid receptor 1, FFAR1, FFAR1 agonists, diabetes mellitus, G protein-coupled receptor 40 (GPR40), GPR40 agonists, GPR40 ligands, type 2 diabetes mellitus and T2DM.

RESULTS

The present review article gives a brief overview of FFAR1, its role in T2DM, recent developments in small molecule FFAR1 (GPR40) agonists reported till now, compounds of natural/plant origin, recent patents published in the last few years, mechanism of FFAR1 activation by the agonists, and clinical status of the FFAR1/GPR40 agonists.

CONCLUSION

The agonists of FFAR1/GRP40 showed considerable potential for the therapeutic control of T2DM. Most of the small molecule FFAR1/GPR40 agonists developed were aryl alkanoic acid derivatives (such as phenylpropionic acids, phenylacetic acids, phenoxyacetic acids, and benzofuran acetic acid derivatives) and thiazolidinediones. Some natural/plant-derived compounds, including fatty acids, sesquiterpenes, phenolic compounds, anthocyanins, isoquinoline, and indole alkaloids, were also reported as potent FFAR1 agonists. The clinical investigations of the FFAR1 agonists demonstrated their probable role in the improvement of glucose control. Though, there are some problems still to be resolved in this field as some FFAR1 agonists terminated in the late phase of clinical studies due to "hepatotoxicity." Currently, PBI-4050 is under clinical investigation by Prometic. Further investigation of pharmacophore scaffolds for FFAR1 full agonists as well as multitargeted modulators and corresponding clinical investigations will be anticipated, which can open up new directions in this area.

Gα12/13 signaling in metabolic diseases

As the key governors of diverse physiological processes, G protein-coupled receptors (GPCRs) have drawn attention as primary targets for several diseases, including diabetes and cardiovascular disease. Heterotrimeric G proteins converge signals from ~800 members of the GPCR family. Among the members of the G protein α family, the Gα₁₂ family members comprising Gα₁₂ and Gα₁₃ have been referred to as gep oncogenes. Gα_12/13 levels are altered in metabolic organs, including the liver and muscles, in metabolic diseases. The roles of Gα_12/13 in metabolic diseases have been investigated. In this review, we highlight findings demonstrating Gα_12/13 amplifying or dampening regulators of phenotype changes. We discuss the molecular basis of G protein biology in the context of posttranslational modifications to heterotrimeric G proteins and the cell signaling axis. We also highlight findings providing insights into the organ-specific, metabolic and pathological roles of G proteins in changes associated with specific cells, energy homeostasis, glucose metabolism, liver fibrosis and the immune and cardiovascular systems. This review summarizes the currently available knowledge on the importance of Gα_12/13 in the physiology and pathogenesis of metabolic diseases, which is presented according to the basic understanding of their metabolic actions and underlying cellular and molecular bases.

Understanding the activities of two members of a vital category of proteins called G proteins, which initiate metabolic changes when signaling molecules bind to cells, could lead to new therapies for many diseases. Researchers in South Korea and Japan, led by Sang Geon Kim at Seoul National University, review the significance of the Gα12 and Gα13 proteins in diseases characterised by significant changes in metabolism, including liver conditions and disorders of the cardiovascular and immune systems. Specific roles for the proteins have been identified by a variety of methods, including studying the effect of disabling the genes that code for them in mice. Recent insights suggest that drugs interfering with the activity of these Gα proteins might help treat many conditions in which the molecular signalling networks involving the proteins are disrupted.

Anti-diabetic drugs recent approaches and advancements

Diabetes is one of the major diseases worldwide and is the third leading cause of death in the United States. Anti-diabetic drugs are used in the treatment of diabetes mellitus to control glucose levels in the blood. Most of the drugs are administered orally, except for a few of them, such as insulin, exenatide, and pramlintide. In this review, we are going to discuss seven major types of anti-diabetic drugs: Peroxisome proliferator-activated receptor (PPAR) agonist, protein tyrosine phosphatase 1B (PTP1B) inhibitors, aldose reductase inhibitors, α-glucosidase inhibitors, dipeptidyl peptidase IV (DPP-4) inhibitors, G protein-coupled receptor (GPCR) agonists and sodium-glucose co-transporter (SGLT) inhibitors. Here, we are also discussing some of the recently reported anti-diabetic agents with its multi-target pharmacological actions. This review summarises recent approaches and advancement in anti-diabetes treatment concerning characteristics, structure-activity relationships, functional mechanisms, expression regulation, and applications in medicine.

Therapeutic potential of ectopic olfactory and taste receptors

Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.

Pharmacological potential of novel agonists for FFAR4 on islet and enteroendocrine cell function and glucose homeostasis

BACKGROUND

To investigate the metabolic effects of FFAR4-selective agonists on islet and enteroendocrine cell hormone release and the combined therapeutic effectiveness with DPP-IV inhibitors.

METHODS

Insulinotropic activity and specificity of FFAR4 agonists were determined in clonal pancreatic BRIN-BD11 cells. Expression of FFAR4 was assessed by qPCR and western blotting following agonist treatment in BRIN-BD11 cells and by immunohistochemistry in mouse islets. Acute in-vivo effects of agonists was investigated after intraperitoneal (i.p.) or oral administration in lean and HFF-obese diabetic mice.

RESULTS

GSK137647 (10^-11-10^-4 M) and Compound-A (10^-10-10^-4 M) stimulated insulin secretion at 5.6 mM (p < 0.05-p < 0.001) and 16.7 mM (p < 0.05-p < 0.001) glucose in BRIN-BD11 cells, with no cytotoxicity effects as assessed by MTT. FFAR4 antagonist (AH-7614) abolished the insulintropic effect of GSK137647 (p < 0.05-p < 0.001), whilst FFAR1 antagonist (GW1100) had no effect. Incubation of BRIN-BD11 cells with GSK137647 and Compound-A increased FFAR4 (p < 0.01) gene expression at 16.7 mM glucose, with a corresponding increase in FFAR4 (p < 0.01) protein concentrations. FFAR4 upregulation was attenuated under normoglycaemic conditions. Immunohistochemistry demonstrated co-localisation of FFAR4 and insulin in mouse islets. Orally administered GSK137647 or Compound-A (0.1 µmol/kgBW) improved glucose tolerance (p < 0.001), increased plasma insulin (p < 0.001), GLP-1 (p < 0.05), GIP (p < 0.05) and induced satiety (p < 0.001) in HFF mice, with glucose-lowering effects enhanced in combination with DPP-IV inhibitor (Sitagliptin) (p < 0.05).

CONCLUSIONS

Specific FFAR4 agonism improves glucose tolerance through insulin and incretin secretion, with enhanced DPP-IV inhibition in combination with Sitagliptin.

GENERAL SIGNIFICANCE

These findings have for the first time demonstrated that selective FFAR4 activation regulates both islet and enteroendocrine hormone function with agonist combinational therapy, presenting a promising strategy for the treatment of type-2-diabetes.

Fasiglifam-Induced Liver Injury in Patients With Type 2 Diabetes: Results of a Randomized Controlled Cardiovascular Outcomes Safety Trial

OBJECTIVE

To evaluate the cardiovascular (CV) safety of fasiglifam, a first-in-man G-protein-coupled receptor 40 (GPR40) agonist, in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A phase 3 multicenter randomized double-blind placebo-controlled two-arm trial was intended to randomize 5,000 participants with type 2 diabetes at high CV risk to fasiglifam or placebo. The primary objective of the trial was to rule out an upper noninferiority bound >1.3 for a one-sided 97.5% confidence limit of the hazard ratio (HR) for CV composite events during treatment with fasiglifam compared with placebo. The primary outcome was the time to first occurrence of any component of the major adverse CV event composite of CV death, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for unstable angina.

RESULTS

The study enrolled 3,207 participants but was terminated because of liver safety concerns. Increased rates of liver enzyme elevation (AST/ALT ≥3-5 × upper limit of normal [ULN]) with fasiglifam were observed. The incidence of ALT or AST ≥3 × ULN with fasiglifam compared with placebo was 2.1% vs. 0.5%, P < 0.001, and the incidence for ≥10 × ULN was 0.31% vs. 0.06%, P < 0.001. A primary CV composite outcome occurred in 40 participants, 2.5% each in the fasiglifam and placebo arms at 12 months (HR 1.05; 95% CI 0.67, 1.63).

CONCLUSIONS

Development of fasiglifam was terminated due to concerns of drug-induced liver injury. Performance of a U.S. Food and Drug Administration-mandated CV outcomes trial supported the termination of the fasiglifam clinical program.

Design, synthesis and structure-activity relationship studies of GPR40 agonists containing amide linker

Free fatty acid receptor 1 (FFAR1/GPR40) attracted significant attention as a potential target for developing novel antidiabetic drugs because of its unique mechanism in glucose homeostasis. Several reports have expressed concerns about central nervous system (CNS) penetration of GPR40 agonists, which is possibly attributed to their high lipophilicity and low total polar surface area. Herein, we report our efforts to improve the physicochemical properties and pharmacokinetic profiles of LY2881835, a GPR40 agonist that had undergone Phase I clinical trial, through a series of structural optimizations. We identified an orally efficacious compound, 15k, which possessed increased plasma exposure, prolonged half-life and reduced CNS exposure and liver to plasma distribution ratio compared with LY2881835. 15k is a potentially valuable lead compound in the development of safe and efficacious GPR40-targeted drugs to treat type 2 diabetes mellitus.

Free fatty acid receptor 1 agonist, MR1704, lowers blood glucose levels in rats unresponsive to the sulfonylurea, glibenclamide

Preclinical Research & Development MR1704 is a selective G protein-coupled receptor 40/free fatty acid receptor 1 agonist, which exhibited favorable pharmacokinetic profiles and glucose-lowering effects in animal models. We studied the effects of MR1704 in a sulfonylurea-desensitized Sprague-Dawley rat model and evaluated the risk of pancreatic β-cell exhaustion compared to that of glibenclamide in Zucker fatty rats. Rats fed ad libitum a diet containing 0.03% glibenclamide exhibited lower non-fasting blood glucose levels compared to those in rats fed a control diet during the first 6 days. However, the response to glibenclamide disappeared on day 9. In a rat oral glucose tolerance test (OGTT), MR1704 reduced the plasma glucose excursion, whereas glibenclamide did not show this effect. In Zucker fatty rats, oral administration of MR1704 reduced glucose excursion during the OGTT, and the effects of MR1704 were maintained after 2-week treatment. In contrast, the glucose-lowering effects of glibenclamide were diminished, and glucose tolerance was aggravated after 2-week treatment. These results indicated that MR1704 provided more sustainable effects compared to those of the sulfonylurea, glibenclamide suggesting that MR1704 may be an attractive therapeutic option for diabetic patients who are unresponsive to sulfonylurea treatment.