Change in hepatic fat content measured by MRI does not predict treatment-induced histological improvement of steatohepatitis

Current Progress and Challenges in the Development of Pharmacotherapy for Metabolic Dysfunction-Associated Steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH), a severe form of metabolic dysfunction-associated steatotic liver disease (MASLD), poses a significant threat to global health. Despite extensive research efforts over the past decade, only one drug has received market approval under accelerated pathways. In this review, we summarise the pathogenesis of MASH and present a comprehensive overview of recent advances in phase 2-3 clinical trials targeting MASH. These trials have highlighted considerable challenges, including low response rates to drugs, limitations of current surrogate histological endpoints, and inadequacies in the design of MASH clinical trials, all of which hinder the progress of MASH pharmacotherapy. We also explored the potential of non-invasive tests to enhance clinical trial design. Furthermore, given the strong association between MASLD and cardiometabolic disorders, we advocate for an integrated approach to disease management to improve overall patient outcomes. Continued investigation into the mechanisms and pharmacology of combination therapies may offer valuable insights for developing innovative MASH treatments.

EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

Nanoformulations for the diagnosis and treatment of metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive phase of metabolic dysfunction-associated steatotic liver disease (MASLD) that develops into irreversible liver cirrhosis and hepatocellular carcinoma, ultimately necessitating liver transplantation as the sole life-saving option. However, given the drawbacks of liver transplantation, including invasiveness, chronic immunosuppression, and a lack of donor livers, prompt diagnosis and effective treatment are indispensable. Due to the limitations of liver biopsy and conventional imaging modalities in diagnosing MASH, as well as the potential hazards associated with liver-protecting medicines, numerous nanoformulations have been created for MASH theranostics. Particularly, there has been significant study interest in artificial nanoparticles, natural biomaterials, and bionic nanoparticles that exhibit exceptional biocompatibility and bioavailability. In this review, we summarized extracellular vesicles (EVs)-based omics analysis and Fe3O4-based functional magnetic nanoparticles as magnetic resonance imaging (MRI) contrast agents for MASH diagnosis. Additionally, artificial nanoparticles such as organic and inorganic nanoparticles, as well as natural biomaterials such as cells and cell-derived EVs and bionic nanoparticles including cell membrane-coated nanoparticles, have also been reported for MASH treatment owing to their specific targeting and superior therapeutic effect. This review has the potential to stimulate advancements in nanoformulation fabrication techniques. By exploring their compatibility with cell biology, it could lead to the creation of innovative material systems for efficient theragnostic uses for MASH. STATEMENT OF SIGNIFICANCE: People with metabolic dysfunction-associated steatohepatitis (MASH) will progress to fibrosis, cirrhosis, or even liver cancer. It is imperative to establish effective theragnostic techniques to stop MASH from progressing into a lethal condition. In our review, we summarize the advancement of artificial, natural, and bionic nanoparticles applied in MASH theragnosis. Furthermore, the issues that need to be resolved for these cutting-edge techniques are summarized to realize a more significant clinical impact. We forecast the key fields that will advance further as nanotechnology and MASH research progress. Generally, our discovery has significant implications for the advancement of nanoformulation fabrication techniques, and their potential to be compatible with cell biology could lead to the creation of innovative materials systems for effective MASH theragnostic.

Insulin resistance is an integral feature of MASLD even in the presence of PNPLA3 variants

Background & Aims

It has been postulated that carriers of PNPLA3 I148M (CG [Ile/Met] or GG [Met/Met]) develop metabolic dysfunction-associated steatotic liver disease (MASLD) in the absence of insulin resistance or metabolic syndrome. However, the relationship between insulin resistance and MASLD according to the PNPLA3 allele has not been carefully assessed.

Methods

A total of 204 participants were recruited and underwent PNPLA3 genotyping, an oral glucose tolerance test, liver proton magnetic resonance spectroscopy and percutaneous liver biopsy if diagnosed with MASLD. A subgroup of patients (n = 55) had an euglycemic hyperinsulinemic clamp with glucose tracer infusion.

Results

As expected, patients with the CG/GG genotype had worse intrahepatic triglyceride content and worse liver histology. However, regardless of PNPLA3 genotype, patients with a diagnosis of MASLD had severe whole-body insulin resistance (Matsuda index, an estimation of insulin resistance in glucose metabolic pathways) and fasting and postprandial adipose tissue insulin resistance (Adipo-IR index and free fatty acid suppression during the oral glucose tolerance test, respectively, as measures of insulin resistance in lipolytic metabolic pathways) compared to patients without MASLD. Moreover, for the same amount of liver fat accumulation, insulin resistance was similar in patients with genotypes CC vs. CG/GG. In multiple regression analyses, A1c and Adipo-IR were associated with the presence of MASLD and advanced liver fibrosis, independently of PNPLA3 genotype.

Conclusions

PNPLA3 variant carriers with MASLD are equally insulin resistant as non-carriers with MASLD at the level of the liver, muscle, and adipose tissue. This calls for reframing "PNPLA3 MASLD" as an insulin-resistant condition associated with increased hepatic susceptibility to metabolic insults, such as obesity or diabetes, wherein early identification and aggressive intervention are warranted to reverse metabolic dysfunction and prevent disease progression.

Impact and implications

It has been proposed that the PNPLA3 G allele is associated with the presence of metabolic dysfunction-associated steatotic liver disease (MASLD) in the absence of insulin resistance. However, our results suggest that regardless of PNPLA3 alleles, the presence of insulin resistance is necessary for the development of MASLD. This calls for reframing patients with "PNPLA3 MASLD" not as insulin sensitive, but on the contrary, as an insulin-resistant population with increased hepatic susceptibility to metabolic insults, such as obesity or diabetes.

EASL-EASD-EASO Clinical Practice Guidelines on the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

Endpoints in NASH Clinical Trials: Are We Blind in One Eye?

This narrative review aims to illustrate the notion that nonalcoholic steatohepatitis (NASH), recently renamed metabolic dysfunction-associated steatohepatitis (MASH), is a systemic metabolic disorder featuring both adverse hepatic and extrahepatic outcomes. In recent years, several NASH trials have failed to identify effective pharmacological treatments and, therefore, lifestyle changes are the cornerstone of therapy for NASH. with this context, we analyze the epidemiological burden of NASH and the possible pathogenetic factors involved. These include genetic factors, insulin resistance, lipotoxicity, immuno-thrombosis, oxidative stress, reprogramming of hepatic metabolism, and hypoxia, all of which eventually culminate in low-grade chronic inflammation and increased risk of fibrosis progression. The possible explanations underlying the failure of NASH trials are also accurately examined. We conclude that the high heterogeneity of NASH, resulting from variable genetic backgrounds, exposure, and responses to different metabolic stresses, susceptibility to hepatocyte lipotoxicity, and differences in repair-response, calls for personalized medicine approaches involving research on noninvasive biomarkers. Future NASH trials should aim at achieving a complete assessment of systemic determinants, modifiers, and correlates of NASH, thus adopting a more holistic and unbiased approach, notably including cardiovascular-kidney-metabolic outcomes, without restricting therapeutic perspectives to histological surrogates of liver-related outcomes alone.

Isotope Labeling and Biochemical Assessment of Liver-Triacylglycerol in Patients with Different Levels of Histologically-Graded Liver Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) prevalence is rapidly growing, and fatty liver has been found in a quarter of the US population. Increased liver lipids, particularly those derived from the pathway of de novo lipogenesis (DNL), have been identified as a hallmark feature in individuals with high liver fat. This has led to much activity in basic science and drug development in this area. No studies to date have investigated the contribution of DNL across a spectrum of disease, although it is clear that inhibition of DNL has been shown to reduce liver fat.

OBJECTIVES

The purpose of this study was to determine whether liver lipid synthesis increases across the continuum of liver injury.

METHODS

Individuals (n = 49) consumed deuterated water for 10 d before their scheduled bariatric surgeries to label DNL; blood and liver tissue samples were obtained on the day of the surgery. Liver lipid concentrations were quantitated, and levels of protein and gene expression assessed.

RESULTS

Increased liver DNL, measured isotopically, was significantly associated with liver fatty acid synthase protein content (R = 0.470, P = 0.003), total steatosis assessed by histology (R = 0.526, P = 0.0008), and the fraction of DNL fatty acids in plasma very low-density lipoprotein-triacylglycerol (R = 0.747, P < 0.001). Regression analysis revealed a parabolic relationship between fractional liver DNL (percent) and NAFLD activity score (R = 0.538, P = 0.0004).

CONCLUSION

These data demonstrate that higher DNL is associated with early to mid stages of liver disease, and this pathway may be an effective target for the treatment of NAFLD and nonalcoholic steatohepatitis. This study was registered at clinicaltrials.gov as NCT03683589.

Clinical Trial Landscape in NASH

Nonalcoholic fatty liver disease consists of a spectrum starting from nonalcoholic fatty liver disease that may progress to nonalcoholic steatohepatitis (NASH), which can lead to fibrosis, cirrhosis, hepatocellular carcinoma, or even liver failure. The prevalence of NASH has increased in parallel with the rising rate of obesity and type 2 diabetes. Given the high prevalence and deadly complications of NASH, there have been significant efforts to develop effective treatments. Phase 2A studies have assessed various mechanisms of action across the spectrum of the disease, while phase 3 studies have focused mainly on NASH and fibrosis stage 2 and higher, as these patients have a higher risk of disease morbidity and mortality. The primary efficacy endpoints also vary, by using noninvasive tests in early-phase trials while relying on liver histological endpoints in phase 3 studies as required by regulatory agencies. Despite initial disappointment due to the failure of several drugs, recent phase 2 and 3 studies have shown promising results, with the first Food and Drug Administration-approved drug for NASH expected to be approved in 2023. In this review, we discuss the various drugs under development for NASH, their mechanisms of action, and the results of their clinical trials. We also highlight the potential challenges in developing pharmacological therapies for NASH.

Comparison of Sodium-Glucose Cotransporter-2 Inhibitors and Thiazolidinediones for Management of Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The pharmacologic treatment of non-alcoholic fatty liver disease (NAFLD) remains unclear.

METHODS

Two reviewers searched PubMed, SCOPUS, Cochrane Central and clinicaltrials.gov for randomized controlled trials (RCTs) of patients with NAFLD with or without type 2 diabetes mellitus (T2DM) receiving TZDs vs SGLT2 inhibitors. The primary outcomes were change in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) and improvement in steatosis and fibrosis. The secondary outcomes were changes in lipid profile, body weight and glycated hemoglobin (HbA1c). Random effects models with continuous outcomes as weighted mean differences (WMD) with 95% confidence intervals (CI) were used.

RESULTS

Five studies (n= 311 NAFLD patients) were included. Patients treated with SGLT2 inhibitors (n= 156) showed significant decrease in visceral fat area (VFA; WMD 23.45, p<0.00001) and body weight (WMD 4.22, p<0.00001) as compared to those treated with TZDs (n= 155). Patients from both groups showed improvement in AST (WMD 1.21, p= 0.40), ALT (WMD -0.46, p= 0.81), GGT (WMD -0.47, p= 0.84), hepatic fibrosis (WMD 0.11, p= 0.52), LDL (WMD 2.19, p= 0.35), HbA1c (WMD -0.16%, p= 0.20), HOMA-IR (WMD: -0.04, p= 0.91) and FPG (WMD -7.37, p= 0.28) which was equivalent and non-significant.

CONCLUSION

The improvement in liver enzymes, steatosis and fibrosis caused by SGLT2 inhibitors and TZDs was similar. SGLT2 inhibitors, however, resulted in a significant decrease in VFA and body weight. As weight loss is found to have a positive effect on the resolution of steatosis and fibrosis in NAFLD patients, SGLT2 inhibitors may have the potential to be considered for long-term management, however, further research needs to be conducted to determine the utility of SGLT2 inhibitor class of antidiabetic drugs for effectively treating NAFLD.

Hepatic and renal improvements with FXR agonist vonafexor in individuals with suspected fibrotic NASH

BACKGROUND & AIMS

The LIVIFY trial investigated the safety, tolerability, and efficacy of vonafexor, a second-generation, non-bile acid farnesoid X receptor agonist in patients with suspected fibrotic non-alcoholic steatohepatitis (NASH).

METHODS

This double-blind phase IIa study was conducted in two parts. Patients were randomised (1:1:1:1) to receive placebo, vonafexor 100 mg twice daily (VONA-100BID), vonafexor 200 mg once daily (VONA-200QD), or 400 mg vonafexor QD (VONA-400QD) in Part A (safety run-in, pharmacokinetics/pharmacodynamics) or placebo, vonafexor 100 mg QD (VONA-100QD), or VONA-200QD (1:1:1) in Part B. The primary efficacy endpoint was a reduction in liver fat content (LFC) by MRI-proton density fat fraction, while secondary endpoints included reduced corrected T1 values and liver enzymes, from baseline to Week 12.

RESULTS

One hundred and twenty patients were randomised (Part A, n = 24; Part B, n = 96). In Part B, there was a significant reduction in least-square mean (SE) absolute change in LFC from baseline to Week 12 for VONA-100QD (-6.3% [0.9]) and VONA-200QD (-5.4% [0.9]), vs. placebo (-2.3% [0.9], p = 0.002 and 0.012, respectively). A >30% relative LFC reduction was achieved by 50.0% and 39.3% of patients in the VONA-100QD and VONA-200QD arms, respectively, but only in 12.5% in the placebo arm. Reductions in body weight, liver enzymes, and corrected T1 were also observed with vonafexor. Creatinine-based glomerular filtration rate improved in the active arms but not the placebo arm. Mild to moderate generalised pruritus was reported in 6.3%, 9.7%, and 18.2% of participants in the placebo, VONA-100QD, and VONA-200QD arms, respectively.

CONCLUSIONS

In patients with suspected fibrotic NASH, vonafexor was safe and induced potent liver fat reduction, improvement in liver enzymes, weight loss, and a possible renal benefit.

CLINICAL TRIAL NUMBER (EUDRACT)

2018-003119-22.

CLINICALTRIALS

GOV IDENTIFIER

NCT03812029.

IMPACT AND IMPLICATIONS

Non-alcoholic steatohepatitis (NASH) has become a leading cause of chronic liver disease worldwide. Affected patients are also at higher risk of developing chronic kidney disease. There are no approved therapies and only few options to treat this population. The phase IIa LIVIFY trial results show that single daily administration of oral vonafexor, an FXR agonist, leads in the short term to a reduction in liver fat, liver enzymes, fibrosis biomarkers, body weight and abdominal circumference, and a possible improvement in kidney function, while possible mild moderate pruritus (a peripheral FXR class effect) and an LDL-cholesterol increase are manageable with lower doses and statins. These results support exploration in longer and larger trials, with the aim of addressing the unmet medical need in NASH.

Challenges and opportunities in NASH drug development

Nonalcoholic fatty liver disease (NAFLD) and its more severe form, nonalcoholic steatohepatitis (NASH), represent a growing worldwide epidemic and a high unmet medical need, as no licensed drugs have been approved thus far. Currently, histopathological assessment of liver biopsies is mandatory as a primary endpoint for conditional drug approval. This requirement represents one of the main challenges in the field, as there is substantial variability in this invasive histopathological assessment, which leads to dramatically high screen-failure rates in clinical trials. Over the past decades, several non-invasive tests have been developed to correlate with liver histology and, eventually, outcomes to assess disease severity and longitudinal changes non-invasively. However, further data are needed to ensure their endorsement by regulatory authorities as alternatives to histological endpoints in phase 3 trials. This Review describes the challenges of drug development in NAFLD-NASH trials and potential mitigating strategies to move the field forward.

Evaluation of PXL065 - deuterium-stabilized (R)-pioglitazone in patients with NASH: A phase II randomized placebo-controlled trial (DESTINY-1)

BACKGROUND & AIMS

Pioglitazone (Pio) is efficacious in NASH, but its utility is limited by PPARγ-driven side effects. Pio is a mixture of two enantiomers (R, S). PXL065, deuterium-stabilized R-Pio, lacks PPARγ activity but retains non-genomic activity. We tested the hypothesis that PXL065 would have similar efficacy but a better safety profile than Pio in patients with NASH.

METHODS

Patients (≥8% liver fat, NAFLD activity score [NAS] ≥4, F1-F3) received daily doses of PXL065 (7.5, 15, 22.5 mg) or placebo 1:1:1:1 for 36 weeks. The primary endpoint was relative % change in liver fat content (LFC) on MRI-proton density fat fraction; liver histology, non-invasive tests, safety-tolerability, and pharmacokinetics were also assessed.

RESULTS

One hundred and seventeen patients were evaluated. All PXL065 groups met the primary endpoint (-21 to (-25% LFC, p = 0.008-0.02 vs. placebo); 40% (22.5 mg) achieved a ≥30% LFC reduction. Favorable trends in non-invasive tests including reductions in PIIINP (p = 0.02, 22.5 mg) and NAFLD fibrosis score (p = 0.04, 22.5 mg) were observed. On histology (n = 92), a ≥1 stage fibrosis improvement occurred in 40% (7.5 mg), 50% (15 mg, p = 0.06), and 35% (22.5 mg) vs. 17% for placebo; up to 50% of PXL065-treated patients achieved a ≥2 point NAS improvement without fibrosis worsening vs. 30% with placebo. Metabolic improvements included: HbA1c (-0.41% p = 0.003) and insulin sensitivity (HOMA-IR, p = 0.04; Adipo-IR, p = 0.002). Adiponectin increased (+114%, 22.5 mg, p <0.0001) vs. placebo. There was no dose-dependent effect on body weight or PXL065-related peripheral oedema signal. Overall, PXL065 was safe and well tolerated. Pharmacokinetics confirmed dose-proportional and higher steady state R- vs. S-Pio exposure.

IMPACT AND IMPLICATIONS

Pioglitazone (Pio) is an approved diabetes medicine with proven efficacy in non-alcoholic steatohepatitis (NASH); PXL065 is a novel related oral agent which has been shown to retain Pio's efficacy in preclinical NASH models, with reduced potential for PPARγ-driven side effects. Results of this phase II study are important as PXL065 improved several key NASH disease features with a favorable safety profile - these findings can be applied by researchers seeking to understand pathophysiology and to develop new therapies. These results also indicate that PXL065 warrants further clinical testing in a pivotal NASH trial. Other implications include the potential future availability of a distinct oral therapy for NASH that may be relevant for patients, providers and caregivers seeking to prevent the progression and complications of this disease.

CONCLUSIONS

PXL065 is a novel molecule which retains an efficacy profile in NASH similar to Pio with reduced potential for PPARγ-driven side effects. A pivotal clinical trial is warranted to confirm the histological benefits reported herein.

IMPACT AND IMPLICATIONS

Pioglitazone (Pio) is an approved diabetes medicine with proven efficacy in non-alcoholic steatohepatitis (NASH); PXL065 is a novel related oral agent which has been shown to retain Pio's efficacy in preclinical NASH models, with reduced potential for PPARγ-driven side effects. Results of this phase II study are important as PXL065 improved several key NASH disease features with a favorable safety profile - these findings can be applied by researchers seeking to understand pathophysiology and to develop new therapies. These results also indicate that PXL065 warrants further clinical testing in a pivotal NASH trial. Other implications include the potential future availability of a distinct oral therapy for NASH that may be relevant for patients, providers and caregivers seeking to prevent the progression and complications of this disease.

Lessons on Drug Development: A Literature Review of Challenges Faced in Nonalcoholic Fatty Liver Disease (NAFLD) Clinical Trials

NAFLD is the most common chronic liver disease worldwide, occurring in both obese and lean patients. It can lead to life-threatening liver diseases and nonhepatic complications, such as cirrhosis and cardiovascular diseases, that burden public health and the health care system. Current care is weight loss through diet and exercise, which is a challenging goal to achieve. However, there are no FDA-approved pharmacotherapies for NAFLD. This review thoroughly examines the clinical trial findings from 22 drugs (Phase 2 and above) and evaluates the future direction that trials should take for further drug development. These trialed drugs can broadly be categorized into five groups-hypoglycemic, lipid-lowering, bile-pathway, anti-inflammatory, and others, which include nutraceuticals. The multitude of challenges faced in these yet-to-be-approved NAFLD drug trials provided insight into a few areas of improvement worth considering. These include drug repurposing, combinations, noninvasive outcomes, standardization, adverse event alleviation, and the need for precision medicine with more extensive consideration of NAFLD heterogenicity in drug trials. Understandably, every evolution of the drug development landscape lies with its own set of challenges. However, this paper believes in the importance of always learning from lessons of the past, with each potential improvement pushing clinical trials an additional step forward toward discovering appropriate drugs for effective NAFLD management.

Differences in HDL-Bound Apolipoproteins in Patients With Advanced Liver Fibrosis Due to Nonalcoholic Fatty Liver Disease

CONTEXT

The mechanisms leading to increased cardiovascular disease in patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis remain incompletely understood.

OBJECTIVE

This study assessed HDL-bound proteins in patients with NAFLD with or without advanced fibrosis.

METHODS

This cross-sectional study at a university hospital included 185 patients with or without type 2 diabetes (T2D). Patients underwent liver proton magnetic resonance spectroscopy to measure intrahepatic triglyceride accumulation and those with NAFLD underwent a percutaneous liver biopsy. Advanced lipid testing with lipoprotein subfraction measurements and targeted proteomics of HDL-bound proteins was performed.

RESULTS

Patients with and without advanced fibrosis had similar clinical characteristics, except for lower HDL-C (34 ± 8 vs 38 ± 9 mg/dL, P = 0.024) and higher prevalence of T2D in advanced fibrosis. Patients with advanced fibrosis had lower HDL particle number. A panel of 28 HDL-bound proteins were targeted and quantified by multiple reaction monitoring liquid chromatography-tandem mass spectrometry. Five proteins were found to be decreased in patients with advanced fibrosis (ApoC-I [P < 0.001], ApoC-IV [P = 0.012], ApoM [P = 0.008], LCAT [P = 0.014], and SAA4 [P = 0.016]). No differences were observed in these proteins in patients with vs without NAFLD or steatohepatitis. The pCAD index, associated with coronary artery disease and cardiovascular mortality, was significantly higher in patients with advanced fibrosis (97 ± 5 vs 86 ± 25, P = 0.04).

CONCLUSION

Patients with NAFLD with advanced fibrosis showed significant differences in HDL-bound protein levels; this translated into increased cardiovascular risk based on pCAD index. Different lipoprotein composition and function may explain the link between liver disease and increased cardiovascular mortality in these patients.

Exosomal microRNAs and Progression of Nonalcoholic Steatohepatitis (NASH)

Nonalcoholic fatty liver disease (NAFLD)/metabolic associated fatty liver disease (MAFLD) is becoming a public health problem worldwide. Steatosis as the simple form and nonalcoholic steatohepatitis (NASH) as its progression form are commonly seen in liver biopsy specimens from patients with obesity, diabetes, hyperlipidemia, hypertension, and the use of certain drugs. Patients with NASH and advanced fibrosis were associated with increased risks of liver-related complications, including hepatocellular carcinoma (HCC). However, the mechanisms regarding the progression from simple steatosis to NASH fibrosis remain incompletely understood. Because NASH-caused liver injury is a complex process and multiple cell types are involved, intercellular communication is likely mediated by extracellular vesicles. Exosomes are a type of small extracellular vesicles and contain various cellular molecules, including proteins, messenger RNAs (mRNAs), and microRNAs (miRNAs). MiRNAs are short, non-coding RNA species that are important post-transcriptional regulators of gene expression and may play an important role in the pathogenesis of NALFD/NASH. In this article, we review the articles about NASH and exosomal miRNAs published in the most recent English literature through PubMed search and discuss the most recent criteria for histological diagnosis, pathogenesis from steatosis to NASH, roles of exosomal miRNAs in NASH pathogenesis and progression, as well as their potential in future clinical diagnosis and treatment for patients with NASH.

Schisantherin A alleviates non-alcoholic fatty liver disease by restoring intestinal barrier function

Background

Non-alcoholic fatty liver disease (NAFLD) is intricately linked to dysregulation of the gut–liver axis, and correlated with intestinal inflammation and barrier disruption.

Objectives

To investigate the protective effects and possible molecular mechanism of Schisantherin A (Sin A) in a high-fat diet (HFD) induced NAFLD mouse model.

Methods

HFD-fed NAFLD mice were treated with the vehicle and 80 mg/kg Sin A every day for 6 weeks. The gut permeability of the NAFLD mice was assessed by intestinal permeability assays in vivo and transepithelial electrical resistance (TEER) measurements in vitro were also used to evaluate the function of the gut barrier. TLR4 inhibitor was then used to investigate the impact of Sin A in the LPS- TLR4 signaling pathway. Alternatively, the composition of the microbiome was assessed using 16S rRNA amplification. Finally, the experiment of antibiotic treatment was performed to elucidate the roles of the gut microbiome mediating Sin A induced metabolic benefits in the NAFLD mice.

Results

We found that Sin A potently ameliorated HFD-induced hepatic steatosis and inflammation, alleviated gut inflammation, and restored intestinal barrier function. We also observed that Sin A improved gut permeability and reduced the release of lipopolysaccharide (LPS) into circulation and further found that Sin A can suppress LPS-TLR4 signaling to protect against HFD-induced NAFLD. Sin A treatment altered the composition of the microbiome in NAFLD mice compared to vehicle controls.

Conclusions

Sin A is an effective and safe hepatoprotective agent against HFD-induced NAFLD by partly ameliorating gut inflammation, restoring intestinal barrier function, and regulating intestinal microbiota composition.

Breakthroughs in therapies for NASH and remaining challenges

Initially a condition that received limited recognition and whose clinical impact was controversial, non-alcoholic steatohepatitis (NASH) has become a leading cause of chronic liver disease. Although there are no approved therapies, major breakthroughs, which will be reviewed here, have paved the way for future therapeutic successes. The unmet medical need in NASH is no longer disputed, and progress in the understanding of its pathogenesis has resulted in the identification of many pharmacological targets. Key surrogate outcomes for therapeutic trials are now accepted by regulatory agencies, thus creating a path for drug registration. A set of non-invasive measurements enabled early-stage trials to be conducted expeditiously, thus providing early indications on the biological and possibly clinical actions of therapeutic candidates. This generated efficacy results for a number of highly promising compounds that are now in late-stage development. Intense research aimed at further improving the assessment of histological endpoints and in developing non-invasive predictive biomarkers is underway. This will help improve the design and feasibility of successful trials, ultimately providing patients with therapeutic options that can change the course of the disease.

Effect of tirzepatide versus insulin degludec on liver fat content and abdominal adipose tissue in people with type 2 diabetes (SURPASS-3 MRI): a substudy of the randomised, open-label, parallel-group, phase 3 SURPASS-3 trial

BACKGROUND

Tirzepatide is a novel dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 receptor agonist under development for the treatment of type 2 diabetes. The aim of this substudy was to characterise the changes in liver fat content (LFC), volume of visceral adipose tissue (VAT), and abdominal subcutaneous adipose tissue (ASAT) in response to tirzepatide or insulin degludec in a subpopulation of the SURPASS-3 study.

METHODS

This substudy of the randomised, open-label, parallel-group, phase 3 SURPASS-3 trial was done at 45 medical research centres and hospitals across eight countries (Argentina, Austria, Greece, Hungary, Italy, Romania, Spain, and the USA). Eligible participants were adults with type 2 diabetes, a baseline HbA_1c 7·0-10·5% (53-91 mmol/mol), a BMI of at least 25 kg/m², stable weight, were insulin-naive, and on treatment with metformin alone or in combination with a SGLT2 inhibitor for at least 3 months before screening. In addition to the main study inclusion criteria, substudy participants had a fatty liver index of at least 60. Participants had an MRI scan and were randomised (1:1:1:1) in the main study to subcutaneous injection once per week of tirzepatide 5 mg, 10 mg, or 15 mg, or subcutaneous injection once per day of titrated insulin degludec, using an interactive web-response system, and were stratified by country, HbA_1c, and concomitant oral anti-hyperglycaemic medication. The primary efficacy endpoint was the change from baseline in LFC (as measured by MRI-proton density fat fraction [MRI-PDFF]) at week 52 using pooled data from the tirzepatide 10 mg and 15 mg groups versus insulin degludec. Analyses were assessed in the enrolled MRI population, which consisted of participants in the modified intention-to-treat population of the main study who also had a valid MRI at either baseline or after baseline. This is a substudy of the trial registered with ClinicalTrials.gov, number NCT03882970, and is complete.

FINDINGS

From April 1, 2019, to Nov 15, 2019, 502 participants were assessed for eligibility to participate in this substudy, 296 (59%) of whom were included in the enrolled MRI population and randomly assigned to treatment (tirzepatide 5 mg, n=71; tirzepatide 10 mg, n=79; tirzepatide 15 mg, n=72; and insulin degludec, n=74). Baseline demographics and clinical characteristics were similar across all treatment groups. From an overall mean baseline LFC of 15·71% (SD 8·93), the absolute reduction in LFC at week 52 was significantly greater for the pooled tirzepatide 10 mg and 15 mg groups (-8·09%, SE 0·57) versus the insulin degludec group (-3·38%, 0·83). The estimated treatment difference versus insulin degludec was -4·71% (95% CI -6·72 to -2·70; p<0·0001). The reduction in LFC was significantly correlated (p≤0·0006) with baseline LFC (ρ=-0·71), reductions in VAT (ρ=0·29), reductions in ASAT (ρ=0·33), and reductions in body weight (ρ=0·34) in the tirzepatide groups.

INTERPRETATION

Tirzepatide showed a significant reduction in LFC and VAT and ASAT volumes compared with insulin degludec in this subpopulation of patients with type 2 diabetes in the SURPASS-3 study. These data provide additional evidence on the metabolic effects of this novel dual GIP and GLP-1 receptor agonist.

FUNDING

Eli Lilly and Company.

Combination therapy with pioglitazone/exenatide/metformin reduces the prevalence of hepatic fibrosis and steatosis: The efficacy and durability of initial combination therapy for type 2 diabetes (EDICT)

AIM

To compare the efficacy of triple therapy (metformin/exenatide/pioglitazone) versus stepwise conventional therapy (metformin → glipizide → glargine insulin) on liver fat content and hepatic fibrosis in newly diagnosed, drug-naïve patients with type 2 diabetes.

METHODS

Sixty-eight patients completed the 6-year follow-up and had an end-of-study (EOS) FibroScan to provide measures of steatosis (controlled attenuation parameter [CAP] in dB/m) and fibrosis (liver stiffness measurement [LSM] in kPa); 59 had magnetic resonance imaging-proton density fat fraction (MRI-PDFF) to measure liver fat.

RESULTS

At EOS, HbA1c was 6.8% and 6.0% in triple and conventional therapy groups, respectively (P = .0006). Twenty-seven of 39 subjects (69%) receiving conventional therapy had grade 2/3 steatosis (CAP, FibroScan) versus nine of 29 (31%) in triple therapy (P = .0003). Ten of 39 (26%) subjects receiving conventional therapy had stage 3/4 fibrosis (LSM) versus two of 29 (7%) in triple therapy (P = .04). Conventional therapy subjects had more liver fat (MRI-PDFF) than triple therapy (12.9% vs. 8.8%, P = .03). The severity of steatosis (CAP) (r = 0.42, P < .001) and fibrosis (LSM) (r = -0.48, P < .001) correlated inversely with the Matsuda Index of insulin sensitivity, but not with percentage body fat. Aspartate aminotransferase (AST) to Platelet Ratio Index (APRI), non-alcoholic fatty liver disease fibrosis score (NFS), plasma AST, and alanine aminotransferase (ALT) all decreased significantly with triple therapy, but only the decrease in plasma AST and ALT correlated with the severity of steatosis and fibrosis at EOS.

CONCLUSIONS

At EOS, subjects with type 2 diabetes treated with triple therapy had less hepatic steatosis and fibrosis versus conventional therapy; the severity of hepatic steatosis and fibrosis were both strongly and inversely correlated with insulin resistance; and changes in liver fibrosis scores (APRI, NFS, Fibrosis-4, and AST/ALT ratio) have limited value in predicting response to therapy.

Impact of PNPLA3 p.I148M and Hepatic Steatosis on Long-Term Outcomes for Hepatocellular Carcinoma and HBsAg Seroclearance in Chronic Hepatitis B

Background

Coexistence of hepatitis B and nonalcoholic fatty liver disease is common; however, little is known about the impact of hepatic steatosis and its major genetic determinants on the natural history of HBV infection. We aimed to study the effects of hepatic steatosis and PNPLA3 variant p.I148M on the risk of hepatocellular carcinoma (HCC) and the lifetime probability of HBsAg seroclearance, which is associated with functional remission and improved long-term outcome of HBV infection.

Methods

We conducted a cohort study of 2385 male, HBsAg-positive Taiwanese civil servants recruited in 1989–1992, and followed up until 2019. Cox regression with competing-risk models was used to estimate sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CIs).

Results

Of 2385 participants, 628 experienced HBsAg seroclearance and 217 developed HCC. Hepatic steatosis, excess body-mass index, and the PNPLA3-148M variant were significantly associated with higher HBsAg seroclearance rate. However, multivariate analyses accounting for HBsAg seroclearance and various HCC risk factors showed that, while steatosis was associated with decreased HCC risk (sHR [95% CI]: 0.49 [0.36–0.66]), carriage of the PNPLA3-148M variant allele (vs II homozygotes: 1.64 [1.20–2.25] for MI heterozygotes; 1.83 [1.20–2.78] for MM homozygotes) and obesity (1.51 [1.07–2.13]) were associated with increased risk. The inverse hepatic steatosis-HCC association persisted after additional adjustment for other viral factors or using different follow-up time cut-offs to account for reverse causality. Moreover, the PNPLA3 MM genotype was positively associated with elevations of ALT and AST and liver cirrhosis, while hepatic steatosis was positively associated with ALT but inversely associated with AST and liver cirrhosis.

Conclusion

Hepatic steatosis and PNPLA3-148M variant appeared to have distinct impacts on the development of HBV-related progressive liver disease and HCC. PNPLA3 p.I148M, but not a diagnosis of hepatic steatosis, can help to identify HBV carriers with high-risk fatty liver disease in the progression to HCC.

EDP-305 in patients with NASH: A phase II double-blind placebo-controlled dose-ranging study

BACKGROUND & AIMS

EDP-305 is an oral farnesoid X receptor (FXR) agonist under development for the treatment of non-alcoholic steatohepatitis (NASH). Herein, we aimed to assess the efficacy, safety and tolerability of EDP-305 in patients with fibrotic NASH.

METHODS

In this double-blind phase II study, patients with fibrotic NASH (without cirrhosis), diagnosed by historical biopsy or phenotypically, were randomized to EDP-305 1 mg, EDP-305 2.5 mg, or placebo, for 12 weeks. The primary endpoint was mean change in alanine aminotransferase (ALT) from baseline to Week 12, and the key secondary endpoint was mean change in liver fat content from baseline to Week 12.

RESULTS

Between January 2018 and July 2019, 134 patients were randomized and 132 were evaluated. At Week 12, the least squares mean reductions from baseline in ALT for patients receiving 2.5 mg EDP-305 and 1 mg EDP-305 were -27.9 U/L (95% CI 0.03 to 24.9; p = 0.049) and -21.7 U/L (-5.8 to 18.3: p = 0.304), respectively, compared to -15.4 U/L for those receiving placebo. Absolute liver fat reduction was -7.1% (2.0-7.5; p = 0.0009) with 2.5 mg EDP-305, -3.3% with EDP-305 1 mg, and -2.4% with placebo. The most common (≥5%) adverse events were pruritus, nausea, vomiting, diarrhea, headache, and dizziness. Pruritus occurred in 50.9%, 9.1%, and 4.2% of patients in the 2.5 mg, 1 mg, and placebo groups, respectively, and led to study drug discontinuation in 20.8% of patients in the 2.5 mg group and 1.8% in the 1 mg group.

CONCLUSIONS

EDP-305 reduced ALT levels and liver fat content, providing support for a longer-term trial assessing histological endpoints in patients with NASH. CLINICALTRIALS.

GOV NUMBER

NCT03421431 LAY SUMMARY: Non-alcoholic fatty liver disease is a chronic hepatic disease that can progress to non-alcoholic steatohepatitis (NASH), which is associated with an increased risk of cirrhosis and liver cancer. Results from this phase II study support continued development of EDP-305, an oral farnesoid X receptor agonist, for the treatment of patients with NASH.

Non-invasive tests of non-alcoholic fatty liver disease

ABSTRACT

For the detection of steatosis, quantitative ultrasound imaging techniques have achieved great progress in past years. Magnetic resonance imaging proton density fat fraction is currently the most accurate test to detect hepatic steatosis. Some blood biomarkers correlate with non-alcoholic steatohepatitis, but the accuracy is modest. Regarding liver fibrosis, liver stiffness measurement by transient elastography (TE) has high accuracy and is widely used across the world. Magnetic resonance elastography is marginally better than TE but is limited by its cost and availability. Several blood biomarkers of fibrosis have been used in clinical trials and hold promise for selecting patients for treatment and monitoring treatment response. This article reviews new developments in the non-invasive assessment of non-alcoholic fatty liver disease (NAFLD). Accumulating evidence suggests that various non-invasive tests can be used to diagnose NAFLD, assess its severity, and predict the prognosis. Further studies are needed to determine the role of the tests as monitoring tools. We cannot overemphasize the importance of context in selecting appropriate tests.

Non-invasive methods for imaging hepatic steatosis and their clinical importance in NAFLD

Hepatic steatosis is a key histological feature of nonalcoholic fatty liver disease (NAFLD). The non-invasive quantification of liver fat is now possible due to advances in imaging modalities. Emerging data suggest that high levels of liver fat and its temporal change, as measured by quantitative non-invasive methods, might be associated with NAFLD progression. Ultrasound-based modalities have moderate diagnostic accuracy for liver fat content and are suitable for screening. However, of the non-invasive imaging modalities, MRI-derived proton density fat fraction (MRI-PDFF) has the highest diagnostic accuracy and is used for trial enrolment and to evaluate therapeutic effects in early-phase clinical trials in nonalcoholic steatohepatitis (NASH). In patients with NAFLD without advanced fibrosis, high levels of liver fat are associated with rapid disease progression. Furthermore, changes on MRI-PDFF (≥30% decline relative to baseline) are associated with NAFLD activity score improvement and fibrosis regression. However, an inverse association exists between liver fat and complications of cirrhosis. Liver fat decreases as liver fibrosis progresses towards cirrhosis, and the clinical importance of quantitative measurements of liver fat differs by NAFLD status. As such, patients with NAFLD should be stratified by fibrosis severity to investigate the utility of quantitative measurements of liver fat for assessing NAFLD progression and prognosis.

Pathologic Diagnosis of Nonalcoholic Fatty Liver Disease

CONTEXT.—

Nonalcoholic fatty liver disease (NAFLD) encompasses steatosis and steatohepatitis. The cause may be multifactorial, and diagnosis requires correlation with clinical information and laboratory results.

OBJECTIVE.—

To provide an overview of the status of histology diagnosis of steatosis, steatohepatitis, and associated conditions.

DATA SOURCES.—

A literature search was performed using the PubMed search engine. The terms ''steatosis,'' ''steatohepatitis,'' ''nonalcoholic fatty liver disease (NAFLD),'' ''nonalcoholic steatohepatitis (NASH),'' "alcoholic steatohepatitis (ASH)," ''type 2 diabetes (T2DM),'' "cryptogenic cirrhosis," "drug-induced liver injury (DILI)," "immune checkpoint inhibitor therapy," and "COVID-19 and liver" were used.

CONCLUSIONS.—

Nonalcoholic fatty liver disease has become the most common chronic liver disease in the United States. NASH is the progressive form of nonalcoholic fatty liver disease. The hallmarks of steatohepatitis are steatosis, ballooned hepatocytes, and lobular inflammation. NASH and alcoholic steatohepatitis share similar histologic features, but some subtle differences may help their distinction. NASH is commonly seen in patients with metabolic dysfunction but can also be caused by other etiologies. Examples are medications including newly developed immune checkpoint inhibitors and viral infections such as coronavirus disease 2019 (COVID-19). NASH is also a common cause of cryptogenic cirrhosis but can be reversed. The results from recent clinical trials for NASH treatment are promising in reducing the severity of steatosis, ballooning, and fibrosis.

Aramchol in patients with nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled phase 2b trial

Nonalcoholic steatohepatitis (NASH), a chronic liver disease without an approved therapy, is associated with lipotoxicity and insulin resistance and is a major cause of cirrhosis and hepatocellular carcinoma. Aramchol, a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1) improved steatohepatitis and fibrosis in rodents and reduced steatosis in an early clinical trial. ARREST, a 52-week, double-blind, placebo-controlled, phase 2b trial randomized 247 patients with NASH (n = 101, n = 98 and n = 48 in the Aramchol 400 mg, 600 mg and placebo arms, respectively; NCT02279524 ). The primary end point was a decrease in hepatic triglycerides by magnetic resonance spectroscopy at 52 weeks with a dose of 600 mg of Aramchol. Key secondary end points included liver histology and alanine aminotransferase (ALT). Aramchol 600 mg produced a placebo-corrected decrease in liver triglycerides without meeting the prespecified significance (-3.1, 95% confidence interval (CI) -6.4 to 0.2, P = 0.066), precluding further formal statistical analysis. NASH resolution without worsening fibrosis was achieved in 16.7% (13 out of 78) of Aramchol 600 mg versus 5% (2 out of 40) of the placebo arm (odds ratio (OR) = 4.74, 95% CI = 0.99 to 22.7) and fibrosis improvement by ≥1 stage without worsening NASH in 29.5% versus 17.5% (OR = 1.88, 95% CI = 0.7 to 5.0), respectively. The placebo-corrected decrease in ALT for 600 mg was -29.1 IU l^-1 (95% CI = -41.6 to -16.5). Early termination due to adverse events (AEs) was <5%, and Aramchol 600 and 400 mg were safe, well tolerated and without imbalance in serious or severe AEs between arms. Although the primary end point of a reduction in liver fat did not meet the prespecified significance level with Aramchol 600 mg, the observed safety and changes in liver histology and enzymes provide a rationale for SCD1 modulation as a promising therapy for NASH and fibrosis and are being evaluated in an ongoing phase 3 program.

Efficacy and safety of PXL770, a direct AMP kinase activator, for the treatment of non-alcoholic fatty liver disease (STAMP-NAFLD): a randomised, double-blind, placebo-controlled, phase 2a study

BACKGROUND

AMP kinase (AMPK) is an energy sensor implicated in regulation of lipid metabolism, inflammation, and insulin sensitivity. We aimed to assess efficacy and safety of PXL770, a novel direct AMPK activator, in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

STAMP-NAFLD, a randomised, double-blind, placebo-controlled phase 2a study, was done across 15 US clinical sites. Patients aged 18-75 years with liver fat content of at least 10% at baseline when assessed by MRI-proton density fat fraction (MRI-PDFF) were eligible. Patients were randomly assigned (1:1:1:1), via an interactive web response system, to receive oral PXL770 250 mg once daily, 250 mg twice daily, or 500 mg once daily, or matched placebo. Patients were stratified according to type 2 diabetes status and study site. The primary endpoint was relative change in liver fat content from baseline compared with placebo at week 12, assessed by MRI-PDFF. The primary endpoint was analysed in an ANCOVA model with treatment and stratification criteria as factors and baseline liver fat content as a covariate in the modified intention-to-treat population, defined as all as-randomised patients who received at least one dose of study treatment. Safety was analysed in the safety population, defined as all as-treated patients receiving at least one dose of the study treatment. The trial has been completed and the final results are reported. The trial is registered with ClinicalTrials.gov, NCT03763877.

FINDINGS

Between March 29, 2019, and March 13, 2020, 387 patients were screened, of whom 120 were included in the modified intention-to-treat and safety analyses (30 in the 250 mg once daily group, 30 in the 250 mg twice daily group, 29 in the 500 mg once daily group, and 31 in the placebo group). The mean relative change from baseline in liver fat content at week 12 was -1·1% in the placebo group, -1·0% in the 250 mg once daily group (mean difference versus placebo 0·1% [95% CI -15·4 to 15·7], p=0·99), -14·3% in the 250 mg twice daily group (-13·1% [-28·1 to 1·8], p=0·084), and -14·7% in the 500 mg once daily group (-13·5% [-28·5 to 1·4], p=0·076). At least one treatment-emergent adverse event occurred in 23 (77%) of 30 patients in the 250 mg once daily group, 20 (67%) of 30 patients in the 250 mg twice daily group, 21 (72%) of 29 patients in the 500 mg once daily group, and 21 (68%) of 31 patients in the placebo group. The most common treatment-emergent adverse event was diarrhoea (five [17%] of patients in the 250 mg once daily group, seven [23%] in the 250 mg twice daily group, six [21%] in the 500 mg once daily group, and none in the placebo group). No life-threatening events or treatment-related deaths occurred.

INTERPRETATION

PXL770 treatment did not meet the primary outcome of liver fat improvement compared with placebo. Treatment was well tolerated. Given indications that metabolic features improved with PXL770 treatment, AMPK activation might be a promising pharmacological target for patients with type 2 diabetes and NAFLD, and could also be considered for further assessment in patients with non-alcoholic steatohepatitis.

FUNDING

Poxel.

Meta-analysis of trials in non-alcoholic fatty liver disease with therapeutic interventions for metabolic syndrome

AIMS

Non-alcoholic fatty liver disease [NAFLD] is associated with metabolic syndrome [MS]. Current guidelines restrict therapy for NAFLD, other than weight loss, in early non-fibrotic disease. It was postulated that intervention with therapies for MS may improve liver fat content.

METHODS

A systematic evaluation of Cochrane and PubMed databases was performed for NAFLD or NASH if they were: 1) interventions for metabolic syndrome or diabetes mellitus 2) randomized controlled trials [RCT], with 3) primary outcomes of liver fat content [LFC] (by magnetic resonance spectroscopy [MRS] or liver biopsy (Nonalcoholic Fatty Liver Disease Activity Score [NAS]).

RESULTS

There were 30 RCT (in 24 publications) of 2409 subjects. LFC decreased with pioglitazone (MRS, -8.0 ± 1.0 %, p < 0.001), diet and exercise (-7.8 ± 1.7 %, p < 0.001) and omega-3 fatty acids (-6.0 ± 2.5 %, p = 0.02). Decreases in NAS scores were significant for pioglitazone (-1.4 ± 0.4 units, p < 0.001) and D&E (-1.0 ± 0.1 units, p < 0.001). Weight loss correlated with improvement in LFC (p < 0.001) and NAS (p < 0.001). Lowered serum triglycerides correlated with final LFC (p < 0.001) and NAS scores (p < 0.001).

CONCLUSIONS

Therapies of MS with weight loss, antiglycemic and triglyceride lowering medicines improved LFC and NAS scores. Further studies are necessary to demonstrate if these therapies would pre-emptively limit progression of disease.

EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis - 2021 update

Non-invasive tests are increasingly being used to improve the diagnosis and prognostication of chronic liver diseases across aetiologies. Herein, we provide the latest update to the EASL Clinical Practice Guidelines on the use of non-invasive tests for the evaluation of liver disease severity and prognosis, focusing on the topics for which relevant evidence has been published in the last 5 years.

Sorafenib reduces steatosis-induced fibrogenesis in a human 3D co-culture model of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) affects around 25% of the worldwide population. Non-alcoholic steatohepatitis (NASH), the more progressive variant of NAFLD, is characterized by steatosis, cellular ballooning, lobular inflammation, and may culminate on hepatic stellate cell (HSC) activation, thus increasing the risk for fibrosis, cirrhosis, and HCC development. Conversely, the antifibrotic effects of sorafenib, an FDA-approved drug for HCC treatment, have been demonstrated in 2D cell cultures and animal models, but its mechanisms in a NAFLD-related microenvironment in vitro requires further investigation. Thus, a human 3D co-culture model of fatty hepatocytes and HSC was established by culturing hepatoma C3A cells, pre-treated with 1.32 mM oleic acid, with HSC LX-2 cells. The fatty C3A/LX-2 spheroids showed morphological and molecular hallmarks of altered lipid metabolism and steatosis-induced fibrogenesis, similarly to the human disease. Sorafenib (15 μM) for 72 hours reduced fatty spheroid viability, and upregulated the expression of lipid oxidation- and hydrolysis-related genes, CPT1 and LIPC, respectively. Sorafenib also inhibited steatosis-induced fibrogenesis by downregulating COL1A1, TGFB1, PDGF, and TIMP1 and by decreasing protein levels of IL-6, TGF-β1, and TNF-α in fatty spheroids. The demonstration of the antifibrotic properties of sorafenib on steatosis-induced fibrogenesis in a 3D in vitro model of NAFLD supports its clinical use as a therapeutic agent for the treatment of NAFLD/NASH patients.

Common Transcriptional Program of Liver Fibrosis in Mouse Genetic Models and Humans

Multifactorial metabolic diseases, such as non-alcoholic fatty liver disease, are a major burden to modern societies, and frequently present with no clearly defined molecular biomarkers. Herein we used system medicine approaches to decipher signatures of liver fibrosis in mouse models with malfunction in genes from unrelated biological pathways: cholesterol synthesis-Cyp51, notch signaling-Rbpj, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling-Ikbkg, and unknown lysosomal pathway-Glmp. Enrichment analyses of Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome and TRANScription FACtor (TRANSFAC) databases complemented with genome-scale metabolic modeling revealed fibrotic signatures highly similar to liver pathologies in humans. The diverse genetic models of liver fibrosis exposed a common transcriptional program with activated estrogen receptor alpha (ERα) signaling, and a network of interactions between regulators of lipid metabolism and transcription factors from cancer pathways and the immune system. The novel hallmarks of fibrosis are downregulated lipid pathways, including fatty acid, bile acid, and steroid hormone metabolism. Moreover, distinct metabolic subtypes of liver fibrosis were proposed, supported by unique enrichment of transcription factors based on the type of insult, disease stage, or potentially, also sex. The discovered novel features of multifactorial liver fibrotic pathologies could aid also in improved stratification of other fibrosis related pathologies.

Sodium-Glucose Cotransporter-2 Inhibitors for Treatment of Nonalcoholic Fatty Liver Disease: A Meta-Analysis of Randomized Controlled Trials

Recent randomized controlled trials (RCTs) tested the efficacy of sodium-glucose cotransporter-2 (SGLT-2) inhibitors to specifically treat nonalcoholic fatty liver disease (NAFLD). We systematically searched three electronic databases (up to 31 October 2020) for identifying placebo-controlled or head-to-head RCTs that used SGLT-2 inhibitors for treatment of NAFLD. No published RCTs with paired liver biopsy data were available for the meta-analysis. Primary outcome measures were changes in serum liver enzyme levels and liver fat content on imaging techniques. Overall, we included a total of twelve RCTs testing the efficacy of dapagliflozin (n = six RCTs), empagliflozin (n = three RCTs), ipragliflozin (n = two RCTs) or canagliflozin (n = one RCT) to specifically treat NAFLD for a median period of 24 weeks with aggregate data on 850 middle-aged overweight or obese individuals with NAFLD (90% with type 2 diabetes). Compared to placebo/reference therapy, treatment with SGLT-2 inhibitors significantly decreased serum alanine aminotransferase (weighted mean differences (WMD): −10.0 IU/L, 95%CI −12.2 to −7.79 IU/L; I² = 10.5%) and gamma-glutamyltransferase levels (WMD: −14.49 IU/L, 95%CI −19.35 to −9.63 IU/L, I² = 38.7%), as well as the absolute percentage of liver fat content on magnetic resonance-based techniques (WMD: −2.05%, 95%CI −2.61 to −1.48%; I² = 0%). In conclusion, SGLT-2 inhibitors seem to be a promising treatment option for NAFLD.

Nonalcoholic Fatty Liver Disease (NAFLD) for Primary Care Providers: Beyond the Liver

Abstract::

Nonalcoholic fatty liver disease (NAFLD) has consolidated as a major public health problem, affecting ~25% of the global population. This percentage is significantly higher in the setting of obesity and/or type 2 diabetes. Presence of NAFLD is associated with severe liver complications, such as nonalcoholic steatohepatitis (NASH; i.e., presence of inflammation and necrosis), cirrhosis and hepatocellular carcinoma. However, the majority of these patients die of cardiovascular disease. For this reason, management of this condition requires a multidisciplinary team, where primary care providers are at center stage. However, important misconceptions remain among primary care providers, preventing them from appropriately approach these patients. Nonalcoholic fatty liver disease should be understood as part of a systemic disease, characterized for abnormal accumulation of fat in tissues other than the adipose tissue. This, in turn, produces dysfunction of those organs or tissues (process sometimes referred to as lipotoxicity). Therefore, due to the systemic nature of this condition, it should not surprise that NAFLD is closely related to other metabolic conditions. In this review, we will focus on the extrahepatic manifestations of NAFLD and its metabolic and cardiovascular implications. We believe these are the most important issues primary care providers should understand, in order to effectively manage these complicated patients. In addition, we have provided a simple and straightforward approach to the diagnosis and treatment of patients with NAFLD and/or NASH. We hope this review will serve as a guide for primary care providers to approach their patients with NAFLD.

Impact of the Analytical Approach on the Reliability of MRI-Based Assessment of Hepatic Fat Content

MRI is a popular noninvasive method for the assessment of liver fat content. After MRI scan acquisition, there is currently no standardized image analysis procedure for the most accurate estimate of liver fat content. We determined intraindividual reliability of MRI-based liver fat measurement using 10 different MRI slice analysis methods in normal-weight, overweight, and obese individuals who underwent 2 same-day abdominal MRI scans. We also compared the agreement in liver fat content between analytical methods and assessed the variability in fat content across the entire liver. Our results indicate that liver fat content varies across the liver, with some slices averaging 54% lower and others 75% higher fat content than the mean of all slices (gold standard). Our data suggest that the entire liver should be contoured on at least every 10th slice to achieve close agreement with the gold standard.

The Asian Pacific Association for the Study of the Liver clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is the principal worldwide cause of liver disease and affects nearly a quarter of the global population. The objective of this work was to present the clinical practice guidelines of the Asian Pacific Association for the Study of the Liver (APASL) on MAFLD. The guidelines cover various aspects of MAFLD including its epidemiology, diagnosis, screening, assessment, and treatment. The document is intended for practical use and for setting the stage for advancing clinical practice, knowledge, and research of MAFLD in adults, with specific reference to special groups as necessary. The guidelines also seek to improve patient care and awareness of the disease and assist stakeholders in the decision-making process by providing evidence-based data. The guidelines take into consideration the burden of clinical management for the healthcare sector.

The role of omics in the pathophysiology, diagnosis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifaceted metabolic disorder, whose spectrum covers clinical, histological and pathophysiological developments ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) and liver fibrosis, potentially evolving into cirrhosis, hepatocellular carcinoma and liver failure. Liver biopsy remains the gold standard for diagnosing NAFLD, while there are no specific treatments. An ever-increasing number of high-throughput Omics investigations on the molecular pathobiology of NAFLD at the cellular, tissue and system levels produce comprehensive biochemical patient snapshots. In the clinical setting, these applications are considerably enhancing our efforts towards obtaining a holistic insight on NAFLD pathophysiology. Omics are also generating non-invasive diagnostic modalities for the distinct stages of NAFLD, that remain though to be validated in multiple, large, heterogenous and independent cohorts, both cross-sectionally as well as prospectively. Finally, they aid in developing novel therapies. By tracing the flow of information from genomics to epigenomics, transcriptomics, proteomics, metabolomics, lipidomics and glycomics, the chief contributions of these techniques in understanding, diagnosing and treating NAFLD are summarized herein.

The relationship between liver triglyceride composition and proton density fat fraction as assessed by 1 H MRS

The aim of this study was to estimate parameters determining liver triglyceride composition (TC) using ¹ H MRS and to assess how TC estimability is affected by proton density fat fraction (PDFF) in adults with nonalcoholic fatty liver disease (NAFLD). In this prospective single-site study, 199 adults with known or suspected NAFLD in whom other causes of liver disease were excluded underwent two ¹ H MRS STimulated Echo Acquisition Method (STEAM) sequences at 3 T. A respiratory-gated water-suppressed free breathing sequence (TE 10 ms, 16 signal averages) was used to assess TC in terms of the number of double bonds (ndb) and methylene-interrupted double bonds (nmidb), and a single breath-hold-long TR, multi-TE sequence (TR 3500 ms), which acquired five single average spectra over TE 10-30 ms, was used to estimate liver PDFF. Ndb and nmidb estimability was qualitatively assessed for each case and summarized descriptively. The consistency of ndb and nmidb estimation was examined using ROC analysis. The relationship between ndb and nmidb values and PDFF was presented graphically. Quality-of-fit of ndb and nmidb versus PDFF was evaluated by Pearson-r correlation. A significance level of 0.05 was used. In 263 ¹ H MRS examinations performed on 199 adult participants, ndb and nmidb were successfully estimated in 7/53 (13.2%) examinations with PDFF < 4%, 13/30 (43.3%) examinations with PDFF between 4% and 7%, 33/41 (80.5%) examinations with PDFF between 7% and 10%, and 124/139 (89.2%) examinations with PDFF > 10% (maximum PDFF 38.1%). Liver TC could be estimated consistently for PDFF > 6.7%. Both ndb and nmidb decreased with increasing PDFF (ndb = 2.83-0.0160·PDFF, r = -0.449, P < 0.0001); nmidb = 0.75-0.0088·PDFF, r = -0.350, P < 0.0001). In a cohort of adults with known or suspected NAFLD, liver TC becomes more saturated as PDFF increases.

Obeticholic acid for the treatment of nonalcoholic steatohepatitis

INTRODUCTION

NAFLD has grown to become the most prevalent liver disease in the world, with a quarter of the general population estimated to have the disease. NASH, characterized as NAFLD with inflammation, is associated with worsening fibrosis along with increased incidence of HCC. Despite high prevalence of this disease, no pharmacologic treatments approved by regulatory agencies are available.

AREAS COVERED

This review briefly discusses present understanding of NASH pathology and currently available treatments. We also discuss data on the role of OCA as an FXR agonist in modulating disease in NASH. A comprehensive literature search of review articles, original research articles, and prospective clinical trials from 1998 to the present was performed.

EXPERT OPINION

Based on 18-month interim findings of the REGENERATE trial, OCA likely improves fibrosis in NASH and therefore may have a beneficial effect in delaying or even preventing cirrhosis. The side effect of an atherogenic lipoprotein profile may adversely affect long-term outcomes, though studies have shown that co-administration of statins is able to mitigate this effect. OCA is likely to become an option for treatment, but the specific context within which it may be prescribed still needs to be clarified.

Confounding factors of non-invasive tests for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects at least 25% of the general adult population worldwide. Because only a fraction of the patients would develop liver-related complications, it is preferable to perform non-invasive tests as the initial assessment. This review summarizes the known and potential confounding factors that affect the performance of non-invasive tests of hepatic steatosis and fibrosis in patients with NAFLD. Clinicians may apply the knowledge and exercise caution in selecting investigations and interpreting test results when confounding factors are present.