In Vitro and In Vivo Characterizations of Chiglitazar, a Newly Identified PPAR Pan-Agonist

Chiglitazar attenuates high-fat diet-induced nonalcoholic fatty liver disease by modulating multiple pathways in mice

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide; however, effective intervention strategies for NAFLD are still unavailable. The present study sought to investigate the efficacy of chiglitazar, a pan-PPAR agonist, in protecting against NAFLD in mice and its underlying molecular mechanism. Male C57BL/6 J mice were fed a high-fat diet (HFD) for 8 weeks to generate NAFLD and the HFD was continued for an additional 10 weeks in the absence or presence of 5 mg/kg/d or 10 mg/kg/d chiglitazar by gavage. Chiglitazar significantly improved dyslipidemia and insulin resistance, ameliorated hepatic steatosis and reduced liver inflammation and oxidative stress in NAFLD mice. RNA-seq revealed that chiglitazar alleviated HFD-induced NAFLD in mice through multiple pathways, including fatty acid metabolism regulation, insulin signaling pathway, and AMPK signaling pathway. This study demonstrated the potential therapeutic effect of chiglitazar on NAFLD. Chiglitazar ameliorated NAFLD by modulating multiple pathways.

Diabetes and Heart Failure: A Literature Review, Reflection and Outlook

Heart failure (HF) is a complex clinical syndrome caused by structural or functional dysfunction of the ventricular filling or blood supply. Diabetes mellitus (DM) is an independent predictor of mortality for HF. The increase in prevalence, co-morbidity and hospitalization rates of both DM and HF has further fueled the possibility of overlapping disease pathology between the two. For decades, antidiabetic drugs that are known to definitively increase the risk of HF are the thiazolidinediones (TZDs) and saxagliptin in the dipeptidyl peptidase-4 (DPP-4) inhibitor, and insulin, which causes sodium and water retention, and whether metformin is effective or safe for HF is not clear. Notably, sodium-glucose transporter 2 (SGLT2) inhibitors and partial glucagon-like peptide-1 receptor agonists (GLP-1 RA) all achieved positive results for HF endpoints, with SGLT2 inhibitors in particular significantly reducing the composite endpoint of cardiovascular mortality and hospitalization for heart failure (HHF). Further understanding of the mutual pathophysiological mechanisms between HF and DM may facilitate the detection of novel therapeutic targets to improve the clinical outcome. This review focuses on the association between HF and DM, emphasizing the efficacy and safety of antidiabetic drugs and HF treatment. In addition, recent therapeutic advances in HF and the important mechanisms by which SGLT2 inhibitors/mineralocorticoid receptor antagonist (MRA)/vericiguat contribute to the benefits of HF are summarized.

Autophagy and mitophagy as potential therapeutic targets in diabetic heart condition: Harnessing the power of nanotheranostics

Autophagy and mitophagy pose unresolved challenges in understanding the pathology of diabetic heart condition (DHC), which encompasses a complex range of cardiovascular issues linked to diabetes and associated cardiomyopathies. Despite significant progress in reducing mortality rates from cardiovascular diseases (CVDs), heart failure remains a major cause of increased morbidity among diabetic patients. These cellular processes are essential for maintaining cellular balance and removing damaged or dysfunctional components, and their involvement in the development of diabetic heart disease makes them attractive targets for diagnosis and treatment. While a variety of conventional diagnostic and therapeutic strategies are available, DHC continues to present a significant challenge. Point-of-care diagnostics, supported by nanobiosensing techniques, offer a promising alternative for these complex scenarios. Although conventional medications have been widely used in DHC patients, they raise several concerns regarding various physiological aspects. Modern medicine places great emphasis on the application of nanotechnology to target autophagy and mitophagy in DHC, offering a promising approach to deliver drugs beyond the limitations of traditional therapies. This article aims to explore the potential connections between autophagy, mitophagy and DHC, while also discussing the promise of nanotechnology-based theranostic interventions that specifically target these molecular pathways.

Design, synthesis, and biological evaluation of piperazine derivatives as pan-PPARs agonists for the treatment of liver fibrosis

Liver fibrosis is commonly occurred in chronic liver diseases, but there is no approved drug for clinical use. The nuclear receptor peroxisome proliferator-activated receptors (PPARs) could not only regulate metabolic homeostasis but also possess anti-inflammatory and antifibrotic effects, and pan-PPARs agonist was considered as a potential anti-liver fibrosis agent. In this study, a series of novel piperazine pan-PPARs agonists were developed, and the preferred compound 12 displayed potent and well-balanced pan-PPARs agonistic activity. Moreover, compound 12 could dose-dependently stimulate the PPARs target genes expression and showed high selectivity over other related nuclear receptors. Importantly, compound 12 exhibited excellent pharmacokinetic profiles and good anti-liver fibrosis effects in vivo. Collectively, compound 12 holds promise for developing an anti-liver fibrosis agent.

A pan-PPAR agonist E17241 ameliorates hyperglycemia and diabetic dyslipidemia in KKAy mice via up-regulating ABCA1 in islet, liver, and white adipose tissue

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is a common chronic metabolic disease. Peroxisome proliferator-activated receptors (PPARs) play crucial roles in regulating glucolipid metabolism. Previous studies showed that E17241 could ameliorate atherosclerosis and lower fasting blood glucose levels in ApoE-/- mice. In this work, we investigated the role of E17241 in glycolipid metabolism in diabetic KKAy mice.

APPROACH AND RESULTS

We confirmed that E17241 is a powerful pan-PPAR agonist with a potent agonistic activity on PPARγ, a high activity on PPARα, and a moderate activity on PPARδ. E17241 also significantly increased the protein expression of ATP-binding cassette transporter 1 (ABCA1), a crucial downstream target gene for PPARs. E17241 clearly lowered plasma glucose levels, improved OGTT and ITT, decreased islet cholesterol content, improved β-cell function, and promoted insulin secretion in KKAy mice. Moreover, E17241 could significantly lower plasma total cholesterol and triglyceride levels, reduce liver lipid deposition, and improve the adipocyte hypertrophy and the inflammatory response in epididymal white adipose tissue. Further mechanistic studies indicated that E17241 boosts cholesterol efflux and insulin secretion in an ABCA1 dependent manner. RNA-seq and qRT-PCR analysis demonstrated that E17241 induced different expression of PPAR target genes in liver and adipose tissue differently from the PPARγ agonist rosiglitazone. In addition, E17241 treatment was also demonstrated to have an exhilarating cardiorenal benefits.

CONCLUSIONS

Our results demonstrate that E17241 regulates glucolipid metabolism in KKAy diabetic mice while having cardiorenal benefits without inducing weight gain. It is a promising drug candidate for the treatment of T2DM.

Impact of chiglitazar on glycemic control in type 2 diabetic patients with metabolic syndrome and insulin resistance: A pooled data analysis from two phase III trials

BACKGROUND

To evaluate the glycemic control effects of vhiglitazar (carfloglitazar), a novel peroxisome proliferator-activated receptor pan-agonist, in patients with type 2 diabetes mellitus (T2DM) with metabolic syndrome (MetS) or insulin resistance (IR) using pooled data analysis of two phase III clinical trials.

METHODS

Data were collected from two randomized phase III clinical trials in China, comparing chiglitazar to placebo or sitagliptin in T2DM patients. The MetS was defined by the Adult Treatment Panel III MetS criteria, and IR was defined by homeostatic model assessment for insulin resistance (HOMA-IR) ≥4.31 (male) or 4.51 (female). The main end point of this analysis was glycemic control in the different arms within each subgroup.

RESULTS

In the MetS subgroup, changes in glycated hemoglobin (HbA1c) from baseline at week 24 in the chiglitazar 32 mg, chiglitazar 48 mg, and sitagliptin 100 mg arms were -1.44%, -1.68%, and -1.37%, respectively; p < .05 was obtained when chiglitazar 48 mg was compared with sitagliptin. In the IR subgroup, the changes in HbA1c were -1.58%, -1.56%, and -1.26% in chiglitazar 32 mg, chiglitazar 48 mg, and sitagliptin 100 mg arms, respectively; p < .05 was obtained when chiglitazar 32 mg was compared with sitaligptin. The two doses of chiglitazar demonstrated a greater reduction in fasting plasma glucose and 2 h postprandial plasma glucose than sitagliptin in the pooled population and in the MetS and IR subgroups.

CONCLUSIONS

Chiglitazar shows promising efficacy for glycemic control in patients with T2DM associated with MetS or IR. Further prospective trials are required to validate these findings.

Plasma proteome profiling reveals the therapeutic effects of the PPAR pan-agonist chiglitazar on insulin sensitivity, lipid metabolism, and inflammation in type 2 diabetes

Chiglitazar is a novel peroxisome proliferator-activated receptor (PPAR) pan-agonist, which passed phase III clinical trials and was newly approved in China for use as an adjunct to diet and exercise in glycemic control in adult patients with Type 2 Diabetes (T2D). To explore the circulating protein signatures associated with the administration of chiglitazar in T2D patients, we conducted a comparative longitudinal study using plasma proteome profiling. Of the 157 T2D patients included in the study, we administered chiglitazar to a specific group, while the controls were given either placebo or sitagliptin. The plasma proteomes were profiled at baseline and 12 and 24 weeks post-treatment using data-independent acquisition mass spectrometry (DIA-MS). Our study indicated that 13 proteins were associated with chiglitazar treatment in T2D patients, including 10 up-regulated proteins (SHBG, TF, APOA2, APOD, GSN, MBL2, CFD, PGLYRP2, A2M, and APOA1) and 3 down-regulated proteins (PRG4, FETUB, and C2) after treatment, which were implicated in the regulation of insulin sensitivity, lipid metabolism, and inflammation response. Our study provides insight into the response of chiglitazar treatment from a proteome perspective and demonstrates the multi-faceted effects of chiglitazar in T2D patients, which will help the clinical application of chiglitazar and further study of its action mechanism.

Effect of Chiglitazar and Sitagliptin on Bone Mineral Density and Body Composition in Untreated Patients with Type 2 Diabetes

Aim

To evaluate the changes in bone mineral density (BMD) and body composition in untreated patients with type 2 diabetes mellitus (T2DM) before and after chiglitazar or sitagliptin treatment.

Methods

A total of 81 patients with T2DM were randomly divided to receive chiglitazar or sitagliptin treatment for 24 weeks (54 in the chiglitazar group and 27 in the sitagliptin group). We measured the spine lumbar BMD, hip BMD, fat mass (FM), fat-free mass (FFM), percent body fat (%BF), android FM, gynoid FM and skeleton muscle mass (SMM) using dual-energy X-ray absorptiometry (DEXA) and examined serum adiponectin (ADP) levels at baseline and the end of the study.

Results

There were no significant changes in the BMD of the L2-4, femoral neck, trochanter or total hip as well as in the BMC after 24 weeks of treatment with chiglitazar or sitagliptin. After chiglitazar administration, the FM, gynoid FM and gynoid to total FM ratio were higher, while the android to total FM ratio and the android to gynoid FM ratio (AOI) were significantly lower. Sitagliptin intervention did not result in statistically significant differences in total fat loss, but it did cause significant decreases in %BF and AOI as well as increases in the FFM, gynoid to total FM ratio and SMM. The ADP levels had significantly negative associations with AOI in all eligible patients.

Conclusion

The chiglitazar had no deleterious effects on BMD and resulted in body fat redistribution in untreated patients with T2DM.

Trial Registration

The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT02173457).

Design of a multi-target focused library for antidiabetic targets using a comprehensive set of chemical transformation rules

Virtual small molecule libraries are valuable resources for identifying bioactive compounds in virtual screening campaigns and improving the quality of libraries in terms of physicochemical properties, complexity, and structural diversity. In this context, the computational-aided design of libraries focused against antidiabetic targets can provide novel alternatives for treating type II diabetes mellitus (T2DM). In this work, we integrated the information generated to date on compounds with antidiabetic activity, advances in computational methods, and knowledge of chemical transformations available in the literature to design multi-target compound libraries focused on T2DM. We evaluated the novelty and diversity of the newly generated library by comparing it with antidiabetic compounds approved for clinical use, natural products, and multi-target compounds tested in vivo in experimental antidiabetic models. The designed libraries are freely available and are a valuable starting point for drug design, chemical synthesis, and biological evaluation or further computational filtering. Also, the compendium of 280 transformation rules identified in a medicinal chemistry context is made available in the linear notation SMIRKS for use in other chemical library enumeration or hit optimization approaches.

International Union of Basic and Clinical Pharmacology CXIII: Nuclear Receptor Superfamily-Update 2023

The NR superfamily comprises 48 transcription factors in humans that control a plethora of gene network programs involved in a wide range of physiologic processes. This review will summarize and discuss recent progress in NR biology and drug development derived from integrating various approaches, including biophysical techniques, structural studies, and translational investigation. We also highlight how defective NR signaling results in various diseases and disorders and how NRs can be targeted for therapeutic intervention via modulation via binding to synthetic lipophilic ligands. Furthermore, we also review recent studies that improved our understanding of NR structure and signaling. SIGNIFICANCE STATEMENT: Nuclear receptors (NRs) are ligand-regulated transcription factors that are critical regulators of myriad physiological processes. NRs serve as receptors for an array of drugs, and in this review, we provide an update on recent research into the roles of these drug targets.

Indirect comparison of efficacy and safety of chiglitazar and thiazolidinedione in patients with type 2 diabetes: A meta-analysis

BACKGROUND

Chiglitazar is an emerging pan-agonist of all peroxisome proliferator activated receptors (PPAR)-α, δ and γ, and has therapeutic potential for type 2 diabetes (T2D). However, to date, no clinical studies or meta-analyses have compared the efficacy and safety of chiglitazar and traditional PPAR-γ agonist thiazolidinediones (TZDs). A meta-analysis concerning this topic is therefore required.

AIM

To compare the efficacy and safety of chiglitazar and TZD in patients with T2D.

METHODS

PubMed, Medline, Embase, the Cochrane Central Register of Controlled Trials, Reference Citation Analysis and Clinicaltrial.gov websites were searched from August 1994 to March 2022. Randomized controlled trials (RCTs) of chiglitazar or TZD vs placebo in patients with T2D were included. Indirect comparisons and sensitivity analyses were implemented to evaluate multiple efficacy and safety endpoints of interest.

RESULTS

We included 93 RCTs that compared TZD with placebo and one that compared chiglitazar with placebo. For efficacy endpoints, the augmented dose of chig-litazar resulted in greater reductions in hemoglobin (Hb)A1c [weighted mean difference (WMD) = -0.15%, 95% confidence interval (CI): -0.27 to -0.04%], triglycerides (WMD = -0.17 mmol/L, 95%CI: -0.24 to -0.11 mmol/L) and alanine aminotransferase (WMD = -5.25 U/L, 95%CI: -8.50 to -1.99 U/L), and a greater increase in homeostasis model assessment-β (HOMA-β) (WMD = 17.75, 95%CI: 10.73-24.77) when compared with TZD treatment. For safety endpoints, the risks of hypoglycemia, edema, bone fractures, upper respiratory tract infection, urinary tract infection, and weight gain were all comparable between the augmented dose of chiglitazar and TZD. In patients with baseline HbA1c ≥ 8.5%, body mass index ≥ 30 kg/m2 or diabetes duration < 10 years, the HbA1c reduction and HOMA-β increase were more conspicuous for the augmented dose of chiglitazar compared with TZD.

CONCLUSION

Augmented dose of chiglitazar, a pan-activator of PPARs, may serve as an antidiabetic agent with preferable glycemic and lipid control, better β-cell function preserving capacity, and does not increase the risk of safety concerns when compared with TZD.

Advances in Studies of Chiglitazar Sodium, a Novel PPAR Pan-Agonist, for the Treatment of Type 2 Diabetes Mellitus

Chiglitazar sodium is a new peroxisome proliferator-activated receptor (PPAR) pan-agonist with independent intellectual property rights in China. It can treat type 2 diabetes mellitus and regulate metabolism by modestly activating PPARα, PPARγ, and PPARδ to improve insulin sensitivity, regulate blood glucose, and promote fatty acid oxidation and utilization. Chiglitazar sodium has a significant insulin-sensitizing effect and is advantageous in reducing fasting and postprandial blood glucose levels, particularly at the 48 mg dose in patients with concomitant high triglycerides in terms of blood glucose and triglyceride level control.

Bcl-2 inhibition combined with PPARα activation synergistically targets leukemic stem cell-like cells in acute myeloid leukemia

Persistence of leukemic stem cells (LSCs) is one of the determining factors to acute myeloid leukemia (AML) treatment failure and responsible for the poor prognosis of the disease. Hence, novel therapeutic strategies that target LSCs are crucial for treatment success. We investigated if targeting Bcl-2 and peroxisome proliferator activated receptor α (PPARα), two distinct cell survival regulating mechanisms could eliminate LSCs. This study demonstrate that the Bcl-2 inhibitor venetoclax combined with the PPARα agonist chiglitazar resulted in synergistic killing of LSC-like cell lines and CD34+ primary AML cells while sparing their normal counterparts. Furthermore, the combination regimen significantly suppressed AML progression in patient-derived xenograft (PDX) mouse models. Mechanistically, chiglitazar-mediated PPARα activation inhibited the transcriptional activity of the PIK3AP1 gene promoter and down-regulated the PI3K/Akt signaling pathway and anti-apoptotic Bcl-2 proteins, leading to cell proliferation inhibition and apoptosis induction, which was synergized with venetoclax. These findings suggest that combinatorial Bcl-2 inhibition and PPARα activation selectively eliminates AML cells in vivo and vitro, representing an effective therapy for patients with relapsed and refractory AML.

Pharmacokinetic Interaction of Chiglitazar with CYP3A4 Inducer or Inhibitor: An Open-Label, Sequential Crossover, Self-Control, 3-Period Study in Healthy Chinese Volunteers

Chiglitazar, a pan agonist of non-thiazolidinedione peroxisome proliferator-activated receptor, has the potential to regulate blood sugar, improve lipid metabolism, and reduce cardiovascular complications. This study aimed to examine the effect of cytochrome P450 (CYP) 3A4 inhibitors/inducers on the in vivo metabolism of chiglitazar and provide a reference for the clinical combination use of chiglitazar. A single-center, open-label, sequential crossover, and self-control study was carried out in 24 healthy subjects to determine the pharmacokinetics of chiglitazar dosed with and without CYP3A4 inhibitors and inducers. The findings showed that the CYP3A4 inhibitor itraconazole had no apparent pharmacokinetic drug interaction with chiglitazar, whereas rifampicin did. When combined with rifampicin after continuous dosing, chiglitazar exposure was not theoretically reduced but increased compared to a single dose of chiglitazar. The possible explanation may be the transporters of bile salt export pump, but this needs to be confirmed. The safety of chiglitazar in single or combination doses was well tolerated. The findings of this study provide a basis for clinical combinations of chiglitazar with CYP3A4 inhibitors or inducers.

2-Phenethylamines in Medicinal Chemistry: A Review

A concise review covering updated presence and role of 2-phenethylamines in medicinal chemistry is presented. Open-chain, flexible alicyclic amine derivatives of this motif are enumerated in key therapeutic targets, listing medicinal chemistry hits and appealing screening compounds. Latest reports in discovering new bioactive 2-phenethylamines by research groups are covered too.

Design of Improved Antidiabetic Drugs: A Journey from Single to Multitarget Agents

Multifactorial diseases exhibit a complex pathophysiology with several factors contributing to their pathogenesis and development. Examples of such disorders are neurodegenerative (e. g. Alzheimer's, Parkinson's) and cardiovascular diseases (e. g. atherosclerosis, metabolic syndrome, diabetes II). Traditional therapeutic approaches with single-target drugs have been proven, in many cases, unsatisfactory for the treatment of multifactorial diseases such as diabetes II. The well-established by now strategy of multitarget drugs is constantly gaining interest and momentum, as a more effective approach. The development of pharmacomolecules able to simultaneously modulate multiple relevant-to-the-disease targets has already several successful examples in various fields and has, as such, inspired the design of multitarget antidiabetic agents; this review highlights the design aspect and efficacy of this approach for improved antidiabetics by presenting several examples of successful pharmacophore combinations in (multitarget) agents that modulate two or more molecular targets involved in diabetes II, resulting in a superior antihyperglycemic profile.

Comparative Evaluation of Chiglitazar and Sitagliptin on the Levels of Retinol-Binding Protein 4 and Its Correlation With Insulin Resistance in Patients With Type 2 Diabetes

AIMS

We evaluated the efficacy and significant changes in the levels of retinol-binding protein 4 (RBP-4) and insulin resistance in patients with type 2 diabetes mellitus (T2DM) treated with chiglitazar versus sitagliptin.

METHODS

Eighty-one T2DM patients with haemoglobin A1c (HbA1c) level of 7.5%-10.0% were selected. Based on the study criteria, patients were randomly assigned to receive chiglitazar (32 mg), chiglitazar (48 mg), or sitagliptin (100 mg) orally for 24 weeks. Sociodemographic and anthropometric characteristics, lipid profiles, glucose profiles, and serum RBP-4 levels were determined at baseline and at the end of the therapy.

RESULTS

After treatment for 24 weeks, significant changes in fasting blood glucose (FBG), fasting insulin (Fins), 2 h-blood glucose (2h-BG), the score values of insulin resistance/insulin secretion/β cell function (HOMA-IR, HOMA-IS, and HOMA-β), triglyceride (TG), free fatty acid (FFA), high-density lipoprotein cholesterol (HDL-C), and RBP-4 levels were detected in patients with chiglitazar administration and sitagliptin administration. Changes in RBP-4 levels were positively correlated with changes in HOMA-IR and 2 h-BG in linear regression.

CONCLUSIONS

Chiglitazar showed a greater improvement in parameters of diabetes than sitagliptin, and changes in serum RBP-4 levels were associated with changes in insulin-sensitizing parameters.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, CT.gov identifier: NCT02173457.

Effect of chiglitazar and sitagliptin on glucose variations, insulin resistance and inflammatory-related biomarkers in untreated patients with type 2 diabetes

AIMS

To evaluate glycemic variations, changes in insulin resistance and oxidative stress after chiglitazar or sitagliptin treatment in untreated patients with type 2 diabetes mellitus (T2DM).

METHODS

Based on the study inclusion and exclusion criteria, 81 patients with T2DM were randomly divided to receive chiglitazar or sitagliptin treatment for 24 weeks. Continuous glucose monitoring (CGM) systems were conducted for 72 h in eligible patients. We analyzed the following glycemic variation parameters derived from the CGM data and measured the serum levels of hemoglobin A1c (HbA1c), fasting blood glucose (FBG), 2-h postprandial blood glucose (2-h PBG), fasting insulin (Fins) and inflammatory-related indicators at baseline and the end of the study.

RESULTS

After treatment for 24 weeks, our data showed a similar reduction in HbA1c between chiglitazar and sitagliptin. The 24-h mean blood glucose (MBG), standard deviation (SD) and mean amplitude of glycemic excursion (MAGE) were significantly decreased, and the time in range (TIR) was increased after chiglitazar and sitagliptin therapy. Chiglitazar administration led to significant improvement in insulin resistance/insulin secretion (HOMA-IR, HOMA-IS), interleukin-6 (IL-6), prostaglandin F2α (PGF-2α), 17-hydroxyprogesterone (17-OHP) and adiponectin (ADP) score values compared with sitagliptin administration.

CONCLUSIONS

Chiglitazar therapy effectively reduced glucose variation and showed a larger improvement in insulin resistance and inflammatory parameters than sitagliptin.

PPAR control of metabolism and cardiovascular functions

Peroxisome proliferator-activated receptor-α (PPARα), PPARδ and PPARγ are transcription factors that regulate gene expression following ligand activation. PPARα increases cellular fatty acid uptake, esterification and trafficking, and regulates lipoprotein metabolism genes. PPARδ stimulates lipid and glucose utilization by increasing mitochondrial function and fatty acid desaturation pathways. By contrast, PPARγ promotes fatty acid uptake, triglyceride formation and storage in lipid droplets, thereby increasing insulin sensitivity and glucose metabolism. PPARs also exert antiatherogenic and anti-inflammatory effects on the vascular wall and immune cells. Clinically, PPARγ activation by glitazones and PPARα activation by fibrates reduce insulin resistance and dyslipidaemia, respectively. PPARs are also physiological master switches in the heart, steering cardiac energy metabolism in cardiomyocytes, thereby affecting pathological heart failure and diabetic cardiomyopathy. Novel PPAR agonists in clinical development are providing new opportunities in the management of metabolic and cardiovascular diseases.

Chiglitazar: First Approval

Chiglitazar (Bilessglu^®) is an orally administered, non-thiazolidinedione small-molecule agonist of α, δ and γ peroxisome proliferator-activated receptors (PPARs) being developed by Chipscreen Biosciences for the treatment of type 2 diabetes (T2D) and non-alcoholic steatohepatitis. In October 2021, chiglitazar was approved in China for use as an adjunct to diet and exercise to improve glycaemic control in adult patients with T2D. The drug is also in phase 2 clinical development in China for the treatment of non-alcoholic steatohepatitis. This article summarizes the milestones in the development of chiglitazar leading to this first approval for the treatment of T2D.

Efficacy and safety of chiglitazar, a novel peroxisome proliferator-activated receptor pan-agonist, in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled, phase 3 trial (CMAP)

Chiglitazar (Carfloglitazar) is a novel non-thiazolidinedione (TZD) structured peroxisome proliferator-activated receptor (PPAR) pan-agonist that has shown promising effects on glycemic control and lipid regulation in patients with type 2 diabetes in previous clinical studies. This randomized phase 3 trial aimed to compare the efficacy and safety of chiglitazar with placebo in patients with type 2 diabetes with insufficient glycemic control by strict diet and exercise alone. Eligible patients were randomly assigned to receive chiglitazar 32 mg (n = 167), chiglitazar 48 mg (n = 166), or placebo (n = 202) once daily. The primary endpoint was the change in glycosylated hemoglobin A_1c (HbA_1c) at week 24 with superiority of chiglitazar over placebo. The results showed that both chiglitazar 32 and 48 mg resulted in significant and clinically meaningful reductions in HbA_1c, and placebo-adjusted estimated treatment differences at week 24 for chiglitazar 32 and 48 mg were -0.87% (95% confidential interval (CI): -1.10 to -0.65; P < 0.0001) and -1.05% (95% CI: -1.29 to -0.81; P < 0.0001), respectively. Secondary efficacy parameters including glycemic control, insulin sensitivity and triglyceride reduction were also significantly improved in the chiglitazar groups. The overall frequency of adverse events and study discontinuation attributable to adverse events were similar among the groups. Low incidences of mild edema and body weight gain were reported in the chiglitazar dose groups. The results from this phase 3 trial demonstrated that the PPAR pan-agonist chiglitazar possesses an overall good efficacy and safety profile in patients with type 2 diabetes inadequately controlled with lifestyle interventions, thereby providing adequate supporting evidence for using this PPAR pan-agonist as a treatment option for type 2 diabetes.

Chiglitazar monotherapy with sitagliptin as an active comparator in patients with type 2 diabetes: a randomized, double-blind, phase 3 trial (CMAS)

Chiglitazar (Carfloglitazar) is a novel peroxisome proliferator-activated receptor (PPAR) pan-agonist that has shown promising effects on glycemic control and lipid regulation in patients with type 2 diabetes. In this randomized phase 3 trial, we compared the efficacy and safety of chiglitazar with sitagliptin in patients with type 2 diabetes who had insufficient glycemic control despite a strict diet and exercise regimen. Eligible patients were randomized (1:1:1) to receive chiglitazar 32 mg (n = 245), chiglitazar 48 mg (n = 246), or sitagliptin 100 mg (n = 248) once daily for 24 weeks. The primary endpoint was the change in glycosylated hemoglobin A_1C (HbA_1c) from baseline at week 24 with the non-inferiority of chiglitazar over sitagliptin. Both chiglitazar and sitagliptin significantly reduced HbA_1c at week 24 with values of -1.40%, -1.47%, and -1.39% for chiglitazar 32 mg, chiglitazar 48 mg, and sitagliptin 100 mg, respectively. Chiglitazar 32 and 48 mg were both non-inferior to sitagliptin 100 mg, with mean differences of -0.04% (95% confidential interval (CI) -0.22 to 0.15) and -0.08% (95% CI -0.27 to 0.10), respectively. Compared with sitagliptin, greater reduction in fasting and 2-h postprandial plasma glucose and fasting insulin was observed with chiglitazar. Overall adverse event rates were similar between the groups. A small increase in mild edema in the chiglitazar 48 mg group and slight weight gain in both chiglitazar groups were reported. The overall results demonstrated that chiglitazar possesses good efficacy and safety profile in patients with type 2 diabetes inadequately controlled with lifestyle interventions, thereby providing adequate supporting evidence for using this PPAR pan-agonist as a treatment option for type 2 diabetes.

Pharmacokinetics and Safety of Chiglitazar, a Peroxisome Proliferator-Activated Receptor Pan-Agonist, in Patients < 65 and ≥ 65 Years With Type 2 Diabetes

The effect of age on the pharmacokinetics and safety of chiglitazar was evaluated in patients < 65 and ≥ 65 years with type 2 diabetes mellitus (T2DM). A total of 20 T2DM patients (<65 vs ≥65 years 1:1) completed the study. Patients received multiple doses of 48 mg chiglitazar once daily for 7 days consecutively. After the first dosing, chiglitazar maximum plasma concentration (C_max ) and area under the plasma concentration-time curve (AUC) in patients ≥ 65 years were similar to those observed in patients < 65 years, with the geometric mean ratio (GMR) for C_max and AUC being 97.22% and 96.83%, respectively. No significant difference was observed in C_max (GMR, 97.23%) in the steady state. Compared with the patients < 65 years, a slight increase (8%-13%) of AUC was observed in the patients ≥ 65 years after multiple doses. Chiglitazar was generally well tolerated following multiple doses in both age groups. In conclusion, there were no significant clinical influences on the pharmacokinetic properties and safety profiles of chiglitazar between patients with T2DM < 65 and ≥ 65 years, indicating that in the future it is not required to adjust the dosing regimen by age for T2DM patients ≥ 65 years.

To Probe Full and Partial Activation of Human Peroxisome Proliferator-Activated Receptors by Pan-Agonist Chiglitazar Using Molecular Dynamics Simulations

Chiglitazar is a promising new-generation insulin sensitizer with low reverse effects for the treatment of type II diabetes mellitus (T2DM) and has shown activity as a nonselective pan-agonist to the human peroxisome proliferator-activated receptors (PPARs) (i.e., full activation of PPARγ and a partial activation of PPARα and PPARβ/δ). Yet, it has no high-resolution complex structure with PPARs and its detailed interactions and activation mechanism remain unclear. In this study, we docked chiglitazar into three experimentally resolved crystal structures of hPPAR subtypes, PPARα, PPARβ/δ, and PPARγ, followed by 3 μs molecular dynamics simulations for each system. Our MM-GBSA binding energy calculation revealed that chiglitazar most favorably bound to hPPARγ (-144.6 kcal/mol), followed by hPPARα (-138.0 kcal/mol) and hPPARβ (-135.9 kcal/mol), and the order is consistent with the experimental data. Through the decomposition of the MM-GBSA binding energy by residue and the use of two-dimensional interaction diagrams, key residues involved in the binding of chiglitazar were identified and characterized for each complex system. Additionally, our detailed dynamics analyses support that the conformation and dynamics of helix 12 play a critical role in determining the activities of the different types of ligands (e.g., full agonist vs. partial agonist). Rather than being bent fully in the direction of the agonist versus antagonist conformation, a partial agonist can adopt a more linear conformation and have a lower degree of flexibility. Our finding may aid in further development of this new generation of medication.

PPARs as Nuclear Receptors for Nutrient and Energy Metabolism

It has been more than 36 years since peroxisome proliferator-activated receptors (PPARs) were first recognized as enhancers of peroxisome proliferation. Consequently, many studies in different fields have illustrated that PPARs are nuclear receptors that participate in nutrient and energy metabolism and regulate cellular and whole-body energy homeostasis during lipid and carbohydrate metabolism, cell growth, cancer development, and so on. With increasing challenges to human health, PPARs have attracted much attention for their ability to ameliorate metabolic syndromes. In our previous studies, we found that the complex functions of PPARs may be used as future targets in obesity and atherosclerosis treatments. Here, we review three types of PPARs that play overlapping but distinct roles in nutrient and energy metabolism during different metabolic states and in different organs. Furthermore, research has emerged showing that PPARs also play many other roles in inflammation, central nervous system-related diseases, and cancer. Increasingly, drug development has been based on the use of several selective PPARs as modulators to diminish the adverse effects of the PPAR agonists previously used in clinical practice. In conclusion, the complex roles of PPARs in metabolic networks keep these factors in the forefront of research because it is hoped that they will have potential therapeutic effects in future applications.

Study on Drug-Drug Interactions Between Chiglitazar, a Novel PPAR Pan-Agonist, and Metformin Hydrochloride in Healthy Subjects

Chiglitazar (CHI) is a potent and selective peroxisome proliferator-activated receptor potentially for the treatment of patients with type 2 diabetes mellitus (T2DM). An open-label, randomized, 3-period crossover and self-controlled study was conducted to investigate drug-drug interaction potential between CHI and metformin hydrochloride (MET). Eligible subjects received a single oral dose of CHI (48 mg), MET (1000 mg), or a combination in each period, followed by serial blood sampling collected for up to 48 hours postdose, and safety was assessed throughout the trial. The area under the plasma concentration-time curves from time 0 to 48 hours (AUC_0-48 h ) of CHI was similar following administration alone or with MET (AUC_0-48h , 12 540 ng·h/mL [9811-15 269 ng·h/mL] vs 12 130 ng·h/mL [9304-14 956 ng·h/mL]; 90% confidence interval [CI] of its geometric mean ratio [GMR], 89.7%-103.8%), whereas the maximum concentration (C_max ) of CHI was reduced during coadministration, as its 90%CI of the GMR was slightly outside the acceptance range for bioequivalence (C_max , 1620 ng/mL [1418-1822 ng/mL] vs 1420 ng/mL [1049-1791 ng/mL], 90%CI GMR, 77.%-94.1%). However, it was not considered clinically meaningful. The MET exposures remained consistent in the absence or presence of CHI (AUC_0-48 h , 12 570 ng·h/mL [10681-14 459 ng·h/mL] vs 13 190 [10973-15 407 ng·h/mL); 90%CI of GMR: 99.1%-110.5%; C_max , 1790 ng/mL [1448-2132 ng/mL] vs 1820 ng/mL [1510-2130 ng/mL]; 90%CI of GMR, 94.2%-110.9%). No moderate to severe adverse events were reported. Our study indicated no clinically significant pharmacokinetic drug-drug interaction between CHI and MET and demonstrated good tolerance in subjects. These results support future application of CHI in combination with MET for treatment of T2DM.

Design, synthesis, in vitro, in vivo and in silico pharmacological characterization of antidiabetic N-Boc-l-tyrosine-based compounds

In this study, we synthesized five N-Boc-L-tyrosine-based analogues to glitazars. The in vitro effects of compounds 1-5 on protein tyrosine phosphatase 1B (PTP-1B), peroxisome proliferator-activated receptor alpha and gamma (PPARα/γ), glucose transporter type-4 (GLUT-4) and fatty acid transport protein-1 (FATP-1) activation are reported in this paper. Compounds 1 and 3 were the most active in the in vitro PTP-1B inhibition assay, showing IC₅₀s of approximately 44 μM. Treatment of adipocytes with compound 1 increased the mRNA expression of PPARγ and GLUT-4 by 8- and 3-fold, respectively. Moreover, both compounds (1 and 3) also increased the relative mRNA expression of PPARα (by 8-fold) and FATP-1 (by 15-fold). Molecular docking studies were performed in order to elucidate the polypharmacological binding mode of the most active compounds on these targets. Finally, a murine model of hyperglycemia was used to evaluate the in vivo effectiveness of compounds 1 and 3. We found that both compounds are orally active using an exploratory dose of 100 mg/kg, decreasing the blood glucose concentration in an oral glucose tolerance test and a non-insulin-dependent diabetes mellitus murine model. In conclusion, we demonstrated that both molecules showed strong in vitro and in vivo effects and can be considered polypharmacological antidiabetic candidates.

The Opportunities and Challenges of Peroxisome Proliferator-Activated Receptors Ligands in Clinical Drug Discovery and Development

Peroxisome proliferator-activated receptors (PPARs) are a well-known pharmacological target for the treatment of multiple diseases, including diabetes mellitus, dyslipidemia, cardiovascular diseases and even primary biliary cholangitis, gout, cancer, Alzheimer's disease and ulcerative colitis. The three PPAR isoforms (α, β/δ and γ) have emerged as integrators of glucose and lipid metabolic signaling networks. Typically, PPARα is activated by fibrates, which are commonly used therapeutic agents in the treatment of dyslipidemia. The pharmacological activators of PPARγ include thiazolidinediones (TZDs), which are insulin sensitizers used in the treatment of type 2 diabetes mellitus (T2DM), despite some drawbacks. In this review, we summarize 84 types of PPAR synthetic ligands introduced to date for the treatment of metabolic and other diseases and provide a comprehensive analysis of the current applications and problems of these ligands in clinical drug discovery and development.

Chiglitazar Preferentially Regulates Gene Expression via Configuration-Restricted Binding and Phosphorylation Inhibition of PPARγ

Type 2 diabetes mellitus is often treated with insulin-sensitizing drugs called thiazolidinediones (TZD), which improve insulin resistance and glycemic control. Despite their effectiveness in treating diabetes, these drugs provide little protection from eminent cardiovascular disease associated with diabetes. Here we demonstrate how chiglitazar, a configuration-restricted non-TZD peroxisome proliferator-activated receptor (PPAR) pan agonist with moderate transcription activity, preferentially regulates ANGPTL4 and PDK4, which are involved in glucose and lipid metabolism. CDK5-mediated phosphorylation at serine 273 (S273) is a unique regulatory mechanism reserved for PPARγ, and this event is linked to insulin resistance in type 2 diabetes mellitus. Our data demonstrates that chiglitazar modulates gene expression differently from two TZDs, rosiglitazone and pioglitazone, via its configuration-restricted binding and phosphorylation inhibition of PPARγ. Chiglitazar induced significantly greater expression of ANGPTL4 and PDK4 than rosiglitazone and pioglitazone in different cell models. These increased expressions were dependent on the phosphorylation status of PPARγ at S273. Furthermore, ChIP and AlphaScreen assays showed that phosphorylation at S273 inhibited promoter binding and cofactor recruitment by PPARγ. Based on these results, activities from pan agonist chiglitazar can be an effective part of a long-term therapeutic strategy for treating type 2 diabetes in a more balanced action among its targeted organs.

A Narrative Review of Potential Future Antidiabetic Drugs: Should We Expect More?

Prevalence of diabetes mellitus, a chronic metabolic disease characterized by hyperglycemia, is growing worldwide. The majority of the cases belong to type 2 diabetes mellitus (T2DM). Globally, India ranks second in terms of diabetes prevalence among adults. Currently available classes of therapeutic agents are used alone or in combinations but seldom achieve treatment targets. Diverse pathophysiology and the need of therapeutic agents with more favourable pharmacokinetic-pharmacodynamics profile make newer drug discoveries in the field of T2DM essential. A large number of molecules, some with novel mechanisms, are in pipeline. The essence of this review is to track and discuss these potential agents, based on their developmental stages, especially those in phase 3 or phase 2. Unique molecules are being developed for existing drug classes like insulins, DPP-4 inhibitors, GLP-1 analogues; and under newer classes like dual/pan PPAR agonists, dual SGLT1/SGLT2 inhibitors, glimins, anti-inflammatory agents, glucokinase activators, G-protein coupled receptor agonists, hybrid peptide agonists, apical sodium-dependent bile acid transporter (ASBT) inhibitors, glucagon receptor antagonists etc. The heterogeneous clinical presentation and therapeutic outcomes in phenotypically similar patients is a clue to think beyond the standard treatment strategy.

The Role of Peroxisome Proliferator-Activated Receptor γ in Mediating Cardioprotection Against Ischemia/Reperfusion Injury

Myocardial infarction (MI) is a serious cardiovascular disease resulting in high rates of morbidity and mortality. Although advances have been made in restoring myocardial perfusion in ischemic areas, decreases in cardiomyocyte death and infarct size are still limited, attributing to myocardial ischemia/reperfusion (I/R) injury. It is necessary to develop therapies to restrict myocardial I/R injury and protect cardiomyocytes against further damage after MI. Many studies have suggested that peroxisome proliferator-activated receptor γ (PPARγ), a ligand-inducible nuclear receptor that predominantly regulates glucose and lipid metabolism, is a promising therapeutic target for ameliorating myocardial I/R injury. Thus, this review focuses on the role of PPARγ in cardioprotection during myocardial I/R. The cardioprotective effects of PPARγ, including attenuating oxidative stress, inhibiting inflammatory responses, improving glucose and lipid metabolism, and antagonizing apoptosis, are described. Additionally, the underlying mechanisms of cardioprotective effects of PPARγ, such as regulating the expression of target genes, influencing other transcription factors, and modulating kinase signaling pathways, are further discussed.

PPARs: regulators of metabolism and as therapeutic targets in cardiovascular disease. Part I: PPAR-α

This article provides a comprehensive review about the molecular and metabolic actions of PPAR-α. It describes its structural features, ligand specificity, gene transcription mechanisms, functional characteristics and target genes. In addition, recent progress with the use of loss of function and gain of function mouse models in the discovery of diverse biological functions of PPAR-α, particularly in the vascular system and the status of the development of new single, dual, pan and partial PPAR agonists (PPAR modulators) in the clinical management of metabolic diseases are presented. This review also summarizes the clinical outcomes from a large number of clinical trials aimed at evaluating the atheroprotective actions of current clinically used PPAR-α agonists, fibrates and statin-fibrate combination therapy.

Distinct but complementary contributions of PPAR isotypes to energy homeostasis

Peroxisome proliferator-activated receptors (PPARs) regulate energy metabolism and hence are therapeutic targets in metabolic diseases such as type 2 diabetes and non-alcoholic fatty liver disease. While they share anti-inflammatory activities, the PPAR isotypes distinguish themselves by differential actions on lipid and glucose homeostasis. In this Review we discuss the complementary and distinct metabolic effects of the PPAR isotypes together with the underlying cellular and molecular mechanisms, as well as the synthetic PPAR ligands that are used in the clinic or under development. We highlight the potential of new PPAR ligands with improved efficacy and safety profiles in the treatment of complex metabolic disorders.

Biopharmaceutical Characterization and Bioavailability Study of a Tetrazole Analog of Clofibric Acid in Rat

In the current investigation, the physicochemical, biopharmaceutical and pharmacokinetic characterization of a new clofibric acid analog (Compound 1) was evaluated. Compound 1 showed affinity by lipophilic phase in 1 to 5 pH interval, indicating that this compound would be absorbed favorably in duodenum or jejunum. Also, Compound 1 possess two ionic species, first above of pH 4.43 and, the second one is present over pH 6.08. The apparent permeability in everted sac rat intestine model was 8.73 × 10-6 cm/s in duodenum and 1.62 × 10-5 cm/s in jejunum, suggesting that Compound 1 has low permeability. Elimination constant after an oral administration of 50 μg/kg in Wistar rat was 1.81 h-1, absorption constant was 3.05 h-1, Cmax was 3.57 μg/mL at 0.33 h, AUC0-α was 956.54 μ/mL·h and distribution volume was 419.4 mL. To IV administration at the same dose, ke was 1.21 h-1, Vd was 399.6 mL and AUC0-α was 747.81 μ/mL·h. No significant differences were observed between pharmacokinetic parameters at every administration route. Bioavailability evaluated was 10.4%. Compound 1 is metabolized to Compound 2 probably by enzymatic hydrolysis, and it showed a half-life of 9.24 h. With these properties, Compound 1 would be considered as a prodrug of Compound 2 with potential as an antidiabetic and anti dyslipidemic agent.

PPARs in obesity-induced T2DM, dyslipidaemia and NAFLD

Obesity is a worldwide epidemic that predisposes individuals to cardiometabolic complications, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), which are all related to inappropriate ectopic lipid deposition. Identification of the pathogenic molecular mechanisms and effective therapeutic approaches are highly needed. The peroxisome proliferator-activated receptors (PPARs) modulate several biological processes that are perturbed in obesity, including inflammation, lipid and glucose metabolism and overall energy homeostasis. Here, we review how PPARs regulate the functions of adipose tissues, such as adipogenesis, lipid storage and adaptive thermogenesis, under healthy and pathological conditions. We also discuss the clinical use and mechanism of PPAR agonists in the treatment of obesity comorbidities such as dyslipidaemia, T2DM and NAFLD. First generation PPAR agonists, primarily those acting on PPARγ, are associated with adverse effects that outweigh their clinical benefits, which led to the discontinuation of their development. An improved understanding of the physiological roles of PPARs might, therefore, enable the development of safe, new PPAR agonists with improved therapeutic potential.

Multitargeted bioactive ligands for PPARs discovered in the last decade

Type 2 diabetes took insulin resistance as the main clinical manifestation. PPARs have been reported to be the therapeutic targets of metabolic disorders, such as obesity, hypertension, diabetes, and cardiovascular disease. Previously, PPARγ agonist rosiglitazone was restricted in clinic due to cardiomyocytes infarction, weight gain, and other serious side-effects, which were mainly due to the single and selective PPARγ agonism. In recent years, multitarget-directed PPAR agonists with synergistic reaction as well as fewer side-effect have been the hot topic in designing promising agents. In this review, we updated and generalized the development of PPARγ partial agonists, PPARγ antagonists, PPARα/γ dual agonists, PPARδ partial agonists, PPARδ antagonists, PPARα/δ dual agonists, PPARγ/δ dual agonists, and PPARα/γ/δ pan-agonists published in recent decade. Most of these molecules were modified from known structures or came from high-throughput screening. Among these molecules, some were expected to be promising drugs against metabolic disorders, while others seemed to provide new insight for designing novel PPAR agents.

Addressing unmet medical needs in type 2 diabetes: a narrative review of drugs under development

The global burden of type 2 diabetes is increasing worldwide, and successful treatment of this disease needs constant provision of new drugs. Twelve classes of antidiabetic drugs are currently available, and many new drugs are under clinical development. These include compounds with known mechanisms of action but unique properties, such as once-weekly DPP4 inhibitors or oral insulin. They also include drugs with new mechanisms of action, the focus of this review. Most of these compounds are in Phase 1 and 2, with only a small number having made it to Phase 3 at this time. The new drug classes described include PPAR agonists/modulators, glucokinase activators, glucagon receptor antagonists, anti-inflammatory compounds, G-protein coupled receptor agonists, gastrointestinal peptide agonists other than GLP-1, apical sodium-dependent bile acid transporter (ASBT) inhibitors, SGLT1 and dual SGLT1/SGLT2 inhibitors, and 11beta- HSD1 inhibitors.