Elafibranor, an Agonist of the Peroxisome Proliferator-Activated Receptor-α and -δ, Induces Resolution of Nonalcoholic Steatohepatitis Without Fibrosis Worsening

Concise Review: Current Status and Future Directions on Research Related to Nonalcoholic Fatty Liver Disease

Considered a feature of the metabolic syndrome, nonalcoholic fatty liver disease (NAFLD), is associated with insulin resistance, type 2 diabetes, obesity and drug toxicity. Its prevalence is estimated at about 30% in western countries mainly due to sedentary life styles and high fat diets. Genome-wide association studies have identified polymorphisms in several genes, for example, PNPLA3, and TM6SF2 which confer susceptibility to NAFLD. Here, we review recent findings in the NAFLD field with a particular focus on published transcriptomics datasets which we subject to a meta-analysis. We reveal a common gene signature correlating with the progression of the disease from steatosis and steatohepatitis and reveal that lipogenic and cholesterol metabolic pathways are main actors in this signature. We propose the use of disease-in-a-dish models based on hepatocyte-like cells derived from patient-specific induced pluripotent stem cells (iPSC). These will enable investigations into the contribution of genetic background in the progression from NALFD to non-alcoholic steatohepatitis. Furthermore, an iPSC-based approach should aid in the elucidation of the function of new biomarkers, thus enabling better diagnostic tests and validation of potential drug targets. Stem Cells 2017;35:89-96.

Antifibrotic Effects of the Dual CCR2/CCR5 Antagonist Cenicriviroc in Animal Models of Liver and Kidney Fibrosis

Background & Aims

Interactions between C-C chemokine receptor types 2 (CCR2) and 5 (CCR5) and their ligands, including CCL2 and CCL5, mediate fibrogenesis by promoting monocyte/macrophage recruitment and tissue infiltration, as well as hepatic stellate cell activation. Cenicriviroc (CVC) is an oral, dual CCR2/CCR5 antagonist with nanomolar potency against both receptors. CVC’s anti-inflammatory and antifibrotic effects were evaluated in a range of preclinical models of inflammation and fibrosis.

Methods

Monocyte/macrophage recruitment was assessed in vivo in a mouse model of thioglycollate-induced peritonitis. CCL2-induced chemotaxis was evaluated ex vivo on mouse monocytes. CVC’s antifibrotic effects were evaluated in a thioacetamide-induced rat model of liver fibrosis and mouse models of diet-induced non-alcoholic steatohepatitis (NASH) and renal fibrosis. Study assessments included body and liver/kidney weight, liver function test, liver/kidney morphology and collagen deposition, fibrogenic gene and protein expression, and pharmacokinetic analyses.

Results

CVC significantly reduced monocyte/macrophage recruitment in vivo at doses ≥20 mg/kg/day (p < 0.05). At these doses, CVC showed antifibrotic effects, with significant reductions in collagen deposition (p < 0.05), and collagen type 1 protein and mRNA expression across the three animal models of fibrosis. In the NASH model, CVC significantly reduced the non-alcoholic fatty liver disease activity score (p < 0.05 vs. controls). CVC treatment had no notable effect on body or liver/kidney weight.

Conclusions

CVC displayed potent anti-inflammatory and antifibrotic activity in a range of animal fibrosis models, supporting human testing for fibrotic diseases. Further experimental studies are needed to clarify the underlying mechanisms of CVC’s antifibrotic effects. A Phase 2b study in adults with NASH and liver fibrosis is fully enrolled (CENTAUR Study 652-2-203; NCT02217475).

Pleiotropic Actions of Peroxisome Proliferator-Activated Receptors (PPARs) in Dysregulated Metabolic Homeostasis, Inflammation and Cancer: Current Evidence and Future Perspectives

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) have demonstrated a lot of important effects in the regulation of glucose and lipid metabolism and in the correct functioning of adipose tissue. Recently, many studies have evaluated a possible effect of PPARs on tumor cells. The purpose of this review is to describe the effects of PPARs, their action and their future prospective;

METHODS

Narrative review aimed to synthesize cutting-edge evidence retrieved from searches of computerized databases;

RESULTS

PPARs play a key role in metabolic diseases, which include several cardiovascular diseases, insulin resistance, type 2 diabetes, metabolic syndrome, impaired immunity and the increasing risk of cancer; in particular, PPARα and PPARβ/δ mainly enable energy combustion, while PPARγ contributes to energy storage by enhancing adipogenesis;

CONCLUSION

PPAR agonists could represent interesting types of molecules that can treat not only metabolic diseases, but also inflammation and cancer. Additional research is needed for the identification of high-affinity, high-specificity agonists for the treatment of obesity, type 2 diabetes (T2DM) and other metabolic diseases. Further studies are needed also to elucidate the role of PPARs in cancer.

Treatment of patients with type 2 diabetes and non-alcoholic fatty liver disease: current approaches and future directions

Non-alcoholic fatty liver disease (NAFLD) is reaching epidemic proportions in patients with type 2 diabetes. Patients with NAFLD are at increased risk of more aggressive liver disease (non-alcoholic steatohepatitis [NASH]) and at a higher risk of death from cirrhosis, hepatocellular carcinoma and cardiovascular disease. Dysfunctional adipose tissue and insulin resistance play an important role in the pathogenesis of NASH, creating the conditions for hepatocyte lipotoxicity. Mitochondrial defects are at the core of the paradigm linking chronic excess substrate supply, insulin resistance and NASH. Recent work indicates that patients with NASH have more severe insulin resistance and lipotoxicity compared with matched obese controls with only isolated steatosis. This review focuses on available agents and future drugs under development for the treatment of NAFLD/NASH in type 2 diabetes. Reversal of lipotoxicity with pioglitazone is associated with significant histological improvement, which occurs within 6 months and persists with continued treatment (or for at least 3 years) in patients with prediabetes or type 2 diabetes, holding potential to modify the natural history of the disease. These results also suggest that pioglitazone may become the standard of care for this population. Benefit has also been reported in non-diabetic patients. Recent promising results with glucagon-like peptide 1 receptor agonists have opened another new treatment avenue for NASH. Many agents in Phase 2-3 of development are being tested, aiming to restore glucose/lipid metabolism, ameliorate adipose tissue and liver inflammation, or to inhibit liver fibrosis. By targeting a diversity of relevant pathways, combination therapy in NASH will likely provide greater success in the future. In summary, increased clinical awareness and improved screening strategies (as currently done for diabetic retinopathy and nephropathy) are needed, to translate recent treatment progress into early treatment and improved quality of life for patients with type 2 diabetes and NASH. This review summarises a presentation given at the symposium 'The liver in focus' at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by John Jones, DOI: 10.1007/s00125-016-3940-5 , and by Hannele Yki-Järvinen, DOI: 10.1007/s00125-016-3944-1 ) and a commentary by the Session Chair, Michael Roden (DOI: 10.1007/s00125-016-3911-x ).

Novel Pharmacotherapy Options for NASH

While simple to recommend, diet and lifestyle measures as a first-line therapy for nonalcoholic steatohepatitis (NASH) are hardly a model of successful therapy, as most clinicians can testify. They can be complex to implement, hard to sustain, and of limited efficacy in advanced stages of the disease. The need for specific pharmacotherapy is now acknowledged by practitioners, the pharmaceutical industry, and regulators and is largely expected by patients. The result is a clear move away from products developed second hand for NASH (such as pioglitazone or metformin) or from generic, non-specific hepatoprotectors (such as pentoxifylline, ursodeoxycholic acid, or antioxidants) toward molecules developed and tested specifically for NASH that aim to correct one or several of the pathways of liver injury in this disease. The two most advanced molecules, obeticholic acid and elafibranor, have shown encouraging data on improving hepatic histology. Both compounds appear to clear NASH, with obeticholic acid improving liver fibrosis and elafibranor improving the glycemic and lipid profile. Much larger trials, currently ongoing, will need to confirm these preliminary data and better characterize the safety and tolerability profile. Meanwhile, other compounds are being tested, a few in phase 2b studies (cenicriviroc, aramchol for NASH, and simtuzumab for NASH fibrosis) and many more in earlier, smaller trials. Most of these drug candidates target different pathways, which speaks to the diversity and dynamism of the NASH pipeline.

Treatment of Nonalcoholic Fatty Liver Disease (NAFLD) in patients with Type 2 Diabetes Mellitus

Nonalcoholic fatty liver disease (NAFLD) is believed to be the most common chronic liver disease, affecting at least one-third of the population worldwide. The more aggressive form is known as nonalcoholic steatohepatitis (NASH) and characterized by hepatocyte necrosis and inflammation. The presence of fibrosis is not uncommon. Fibrosis indicates a more aggressive course and patients with NASH that are at high-risk of cirrhosis and premature mortality, as well as at increased risk of hepatocellular carcinoma (HCC). Patients with type 2 diabetes mellitus (T2DM) are at the highest risk for the development of NASH, even in the setting of normal plasma aminotransferase levels. The presence of dysfunctional adipose tissue in most overweight and obese subjects, combined with insulin resistance, hyperglycemia, and atherogenic dyslipidemia, contribute to their increased cardiovascular risk. Many therapeutic agents have been tested for the treatment of NASH but few studies have focused in patients with T2DM. At the present moment, the only FDA-approved agents that in controlled studies have shown to significantly improve liver histology in patients with diabetes are pioglitazone and liraglutide. Current research efforts are centering on the mechanisms for intrahepatic triglyceride accumulation and for the development of steatohepatitis, the role of mitochondrial dysfunction in NASH, and the impact of improving glycemic control per se on the natural history of the disease. This brief review summarizes our current knowledge on the pharmacological agents available for the treatment of NASH to assist healthcare providers in the management of these challenging patients.

Efficacy and safety study of cenicriviroc for the treatment of non-alcoholic steatohepatitis in adult subjects with liver fibrosis: CENTAUR Phase 2b study design

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is often accompanied by liver fibrosis, which can progress to cirrhosis; C-C chemokine receptors type 2 and 5 (CCR2/CCR5), which mediate interactions driving inflammation and fibrosis, are promising treatment targets. Cenicriviroc (CVC), a dual-CCR2/CCR5 antagonist, has potent anti-inflammatory and antifibrotic activity in animal models; in HIV-positive subjects it reduced soluble CD14 levels, aspartate aminotransferase-to-platelet count ratio index, and non-invasive hepatic fibrosis risk scores; favorable tolerability was demonstrated in ~600 subjects. Efficacy and safety of CVC 150 mg for treating NASH with liver fibrosis are being evaluated over 2 years (primary endpoint at Year 1 [Y1]).

DESIGN

Phase 2b, randomized, double-blind, placebo-controlled, multinational study (CENTAUR; NCT02217475). Adults with histological evidence of NASH, non-alcoholic fatty liver disease activity score (NAS) ≥ 4, and liver fibrosis (stages 1-3 NASH clinical research network system) enrolled. Subjects have increased risk of progression to cirrhosis due to ≥1 characteristic: type 2 diabetes; body mass index > 25 kg/m(2) with ≥1 feature of metabolic syndrome; bridging fibrosis and/or NAS ≥ 5. Liver biopsy evaluation at Screening, Y1, and Year 2 (Y2).

OBJECTIVES

Assess histologic improvement (≥2-point in NAS with ≥1-point improvement in >1 category) without worsening of fibrosis at Y1 (primary); evaluate complete NASH resolution without worsening of fibrosis at Y2 (key secondary).

DISCUSSION

CENTAUR is the first prospective study evaluating an oral agent exclusively enrolling subjects with NASH and liver fibrosis, with increased risk of developing cirrhosis. It will compare shorter versus longer CVC treatment and assess correlations between decreased inflammation and fibrosis.

Rationale and Design of RNAFH Study: Effect of Rosuvastatin (10 mg/d) on Nonalcoholic Fatty Liver in Metabolic Syndrome Patients without Overt Diabetes Evaluated by 1H-Magnetic Resonance Spectroscopy

Objective. The RNAFH study (effect of rosuvastatin on nonalcoholic fatty liver disease in metabolic syndrome patients without overt diabetes evaluated by ¹H-MRS) is a prospective randomized, single-center, open-label trail designed to assess the effect of rosuvastatin on the intrahepatocellular lipid (IHCL) level of nonalcoholic fatty liver disease (NAFLD). Methods. 40 NAFLD patients meeting inclusion and exclusion criteria with metabolic syndrome (MS) but without overt diabetes mellitus will be included. Patients will be randomized to 52-week treatment with either rosuvastatin (10 mg/d) or blank control. The primary end point is IHCL evaluated by ¹H-MRS, which was considered to be the most accurate noninvasive method for the evaluation of NAFLD. Secondary end points include homeostasis model assessment of insulin resistance (HOMA-IR) index on behalf of insulin resistance level and lipid parameters. Safety indicators will be monitored such as liver function, renal function, muscle stability, and glucose metabolism. The aims of the present study are noteworthy in respect that (1) IHCL is a quantitative indicator for evaluating the degree of fatty liver disease and ¹H-MRS is a noninvasive technique to provide this specific index precisely, (2) meanwhile the HOMA-IR index and lipid parameters will be monitored, and (3) the safety of rosuvastatin treatment for 52 weeks will be evaluated including glucose metabolism, muscle stability, liver function, and renal function.