Resmetirom (MGL-3196) for the treatment of non-alcoholic steatohepatitis: a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial

Resmetirom and Metabolic Dysfunction-Associated Steatohepatitis: Perspectives on Multidisciplinary Management from Global Healthcare Professionals

PURPOSE OF REVIEW

The approval of resmetirom brings great hope to patients with metabolic dysfunction-associated steatohepatitis (MASH). The purpose of this review is to explore its impact on the global health environment. The implementation of multidisciplinary management MASH is proposed.

RECENT FINDINGS

Resmetirom has benefits in the treatment of MASH, and its safety and effectiveness have been studied. The adverse events (AEs) need to be noticed. To improve patient outcomes, a multimodal approach with medication such as resmetirom, combined with metabolic and bariatric surgery (MBS) and lifestyle interventions can be conducted. MASH, a liver disease linked with obesity, is a challenging global healthcare burden compounded by the absence of any approved pharmacotherapy. The recent conditional approval by the Food and Drug Administration (FDA) in the United States of resmetirom, an oral, liver-directed, thyroid hormone receptor beta-selective agonist, marks a significant milestone, offering a treatment option for adults with non-cirrhotic MASH and who have moderate to advanced liver fibrosis. This narrative review discusses the efficacy and safety of resmetirom and its role in the therapeutic landscape of MASH treatment. Despite the promising hepatoprotective effect of resmetirom on histological liver endpoints, its use need further research, particularly regarding ethnic differences, effectiveness and cost-effectiveness, production scalability, social acceptance and accessibility. In addition, integrating resmetirom with other multidisciplinary therapeutic approaches, including lifestyle changes and MBS, might further improve clinical liver-related and cardiometabolic outcomes of individuals with MASH. This review highlights the importance of a comprehensive treatment strategy, supporting continued innovation and collaborative research to refine treatment guidelines and consensus for managing MASH, thereby improving clinical patient outcomes in the growing global epidemic of MASH. Studies done to date have been relatively short and ongoing, the course of the disease is highly variable, the conditions of various patients vary, and given this complex clinical phenotype, it may take many years of clinical trials to show long-term benefits.

Current and experimental pharmacotherapy for the management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, with its incidence increasing in parallel with the global prevalence of obesity and type 2 diabetes mellitus. Despite our steadily increasing knowledge of its pathogenesis, there is as yet no available pharmacotherapy specifically tailored for NAFLD. To define the appropriate management, it is important to clarify the context in which the disease appears. In the case of concurrent metabolic comorbidities, NAFLD patients are treated by targeting these comorbidities, such as diabetes and obesity. Thus, GLP-1 analogs, PPAR, and SGLT2 inhibitors have recently become central to the treatment of NAFLD. In parallel, randomized trials are being conducted to explore new agents targeting known pathways involved in NAFLD progression. However, there is an imperative need to intensify the effort to design new, safe drugs with biopsy-proven efficacy. Of note, the main target of the pharmacotherapy should be directed to the regression of fibrotic NASH, as this histologic stage has been correlated with increased overall as well as liver-related morbidity and mortality. Herein we discuss the drugs currently at the forefront of NAFLD treatment.

Decreasing the burden of non-alcoholic fatty liver disease: From therapeutic targets to drug discovery opportunities

Non-alcoholic fatty liver disease (NAFLD) presents a pervasive global pandemic, affecting approximately 25 % of the world's population. This grave health issue not only demands urgent attention but also stands as a significant economic concern on a global scale. The genesis of NAFLD can be primarily attributed to unhealthy dietary habits and a sedentary lifestyle, albeit certain genetic factors have also been recorded to contribute to its occurrence. NAFLD is characterized by fat accumulation in more than 5 % of hepatocytes according to histological analysis, or >5.6 % of lipid volume fraction in total liver weight in patients. The pathophysiology of NAFLD/non-alcoholic steatohepatitis (NASH) is multifactorial and the mechanisms underlying the progression to advanced forms remain unclear, thereby representing a challenge to disease therapy. Despite the substantial efforts from the scientific community and the large number of pre-clinical and clinical trials performed so far, only one drug was approved by the Food and Drug Administration (FDA) to treat NAFLD/NASH specifically. This review provides an overview of available information concerning emerging molecular targets and drug candidates tested in clinical studies for the treatment of NAFLD/NASH. Improving our understanding of NAFLD pathophysiology and pharmacotherapy is crucial not only to explore new molecular targets, but also to potentiate drug discovery programs to develop new therapeutic strategies. This knowledge endeavours scientific efforts to reduce the time for achieving a specific and effective drug for NAFLD or NASH management and improve patients' quality of life.

Liver biopsy evaluation in MASH drug development: Think thrice, act wise

During recent decades, the metabolic dysfunction-associated steatohepatitis (MASH) field has witnessed several paradigm shifts, including the recognition of liver fibrosis as the main predictor of major adverse liver outcomes. Throughout this evolution, liver histology has been recognised as one of the main hurdles in MASH drug development due to its invasive nature, associated cost, and high inter- and intra-reader variability. Collective experience demonstrates the importance of consistency in the central reading process, where consensus methods have emerged as appropriate ways to mitigate against well-known challenges. Using crystalized knowledge in the field, stakeholders should collectively work towards the next paradigm shift, where non-invasive biomarkers will be considered surrogate endpoints for accelerated approval. In this review, we provide an overview of the evolution of the regulatory histology endpoints and the liver biopsy reading process, within the MASH trial landscape, over recent decades; we then review the biggest challenges associated with liver biopsy endpoints. Finally, we discuss and provide recommendations on the best practices for liver biopsy evaluation in MASH drug development.

Liver magnetic resonance imaging, non-alcoholic fatty liver disease and metabolic syndrome risk in pre-pubertal Mexican boys

Rising global pediatric obesity rates, increase non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) prevalence, with MetS being a NAFLD risk factor. NAFLD can be asymptomatic, with liver function tests insensitive to mild disease, and liver biopsy, risking complications. Thus, we investigated multiparametric MRI (mpMRI) metrics of liver fat (proton density fat fraction, PDFF) and disease activity (fibro-inflammation; iron-corrected T1, cT1), in a Hispanic pre-pubertal pediatric cohort, with increased risk of NAFLD. Pre-pubertal boys (n = 81) of varying Body-Mass Index (BMI) were recruited in Mexico City. Most children (81%) had normal liver transaminase levels, 38% had high BMI, and 14% had ≥ 3 MetS risk factors. Applying mpMRI thresholds, 12%, 7% and 4% of the cohort had NAFLD, NASH and high-risk NASH respectively. Participants with ≥ 3 MetS risk factors had higher cT1 (834 ms vs. 737 ms, p = 0.004) and PDFF (8.7% vs. 2.2%, p < 0.001) compared to those without risk factors. Those with elevated cT1 tended to have high BMI and high insulin (p = 0.005), HOMA-IR (p = 0.005) and leptin (p < 0.001). The significant association of increased risk of MetS with abnormal mpMRI, particularly cT1, proposes the potential of using mpMRI for routine pediatric NAFLD screening of high-risk (high BMI, high MetS risk score) populations.

Drug treatment for MASLD: Progress and direction

ABSTRACT

Metabolic dysfunction-associated steatotic liver disease (MASLD), also called non-alcoholic fatty liver disease, is the most epidemic chronic liver disease worldwide. Metabolic dysfunction-associated steatohepatitis (MASH) is the critical stage of MASLD, and early diagnosis and treatment of MASH are crucial for reducing the incidence of intrahepatic and extrahepatic complications. So far, pharmacotherapeutics for the treatment of MASH are still a major challenge, because of the complexity of the pathogenesis and heterogeneity of MASH. Many agents under investigation have shown impressive therapeutic effects by targeting different key pathways, including the attenuation of steatohepatitis or fibrosis or both. It is notable that thyroid hormone receptor-β agonist, resmetirom has become the first officially approved drug for treating MASH with fibrosis. Other agents such as peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 analogs, and fibroblast growth factor 21 analogs are awaiting approval. This review focuses on the current status of drug therapy for MASH and summarizes the latest results of new medications that have completed phase 2 or 3 clinical trials, and presents the future directions and difficulties of new drug research for MASH.

Discovery of ZG-2305, an Orally Bioavailable Factor Inhibiting HIF Inhibitor for the Treatment of Obesity and Fatty Liver Disease

Genetic loss of the 2-oxoglutarate oxygenase factor inhibiting hypoxia-inducible factor (FIH) enhances both glycolysis and aerobic metabolism. FIH is thus a potential target for adiposity control and improving hepatic steatosis. We describe development of a series of novel, potent, and selective FIH inhibitors that occupy both the FIH catalytic site and a recently defined tyrosine conformational-flip pocket. ZG-2305, with a Ki of 79.6 nM for FIH, manifests 38-fold selectivity over the hypoxia-inducible factor (HIF) prolyl hydroxylase PHD2. Oral administration of ZG-2305 in the western-diet induced obesity mouse model results in improved lipid accumulation and recovery from abnormal body weight/hepatic steatosis. Amelioration of nonalcoholic steatohepatitis (NASH) related pathological phenotypes in the HF-CDAA-diet induced NASH mouse model was observed. Preliminary preclinical studies indicate ZG-2305 has good pharmacokinetic properties and an acceptable safety profile. The results imply ZG-2305 is a promising candidate for treatment of obesity and fatty liver disease.

Thyroid hormone receptor-β analogs for the treatment of Metabolic Dysfunction-Associated Steatohepatitis (MASH)

The association between suboptimal thyroid function ((sub)clinical hypothyroidism or low normal thyroid function) and the metabolic syndrome and metabolic dysfunction-associated steatotic liver disease (MASLD) is clearly established. Furthermore, in MASLD, thyroid hormones have low intracellular concentrations and the activation of the thyroid hormone receptor (THR) is reduced. Administration of thyroid hormone has been shown to reduce liver triglycerides by stimulating fatty acid disposal through lipophagy and beta-oxidation, and to lower LDL-cholesterol. As thyroid hormone exerts it's effects in many different organs, including heart and bone, several drug candidates have been developed acting as selective thyromimetics for the THR-β nuclear receptor with potent and targeted liver actions. Importantly, these compounds have reduced affinity for the THR-α nuclear receptor and tissue distribution profiles that differ from endogenous thyroid hormones thereby reducing unwanted cardiovascular side effects. The most advanced compound, resmetirom, is an oral drug that demonstrated, in a large phase 3 trial in MASH patients, the ability to remove liver fat, reduce aminotransferase levels and improve atherogenic dyslipidemia with a good tolerability profile. This translated into histological improvement that led to accelerated approval of this drug for active fibrotic steatohepatitis, a milestone achievement as a first MASH drug.

Actions of thyroid hormones and thyromimetics on the liver

Thyroid hormones (triiodothyronine and thyroxine) are pivotal for metabolic balance in the liver and entire body. Dysregulation of the hypothalamus-pituitary-thyroid axis can contribute to hepatic metabolic disturbances, affecting lipid metabolism, glucose regulation and protein synthesis. In addition, reductions in circulating and intrahepatic thyroid hormone concentrations increase the risk of metabolic dysfunction-associated steatotic liver disease by inducing lipotoxicity, inflammation and fibrosis. Amelioration of hepatic metabolic disease by thyroid hormones in preclinical and clinical studies has spurred the development of thyromimetics that target THRB (the predominant thyroid hormone receptor isoform in the liver) and/or the liver itself to provide more selective activation of hepatic thyroid hormone-regulated metabolic pathways while reducing thyrotoxic side effects in tissues that predominantly express THRA such as the heart and bone. Resmetirom, a liver and THRB-selective thyromimetic, recently became the first FDA-approved drug for metabolic dysfunction-associated steatohepatitis (MASH). Thus, a better understanding of the metabolic actions of thyroid hormones and thyromimetics in the liver is timely and clinically relevant. Here, we describe the roles of thyroid hormones in normal liver function and pathogenesis of MASH, as well as some potential clinical issues that might arise when treating patients with MASH with thyroid hormone supplementation or thyromimetics.

Comparative Analysis of Resmetirom vs. FGF21 Analogs vs. GLP-1 Agonists in MASLD and MASH: Network Meta-Analysis of Clinical Trials

INTRODUCTION

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and Metabolic-Dysfunction Associated Steatohepatitis (MASH) are linked to obesity, type 2 diabetes, and metabolic syndrome, increasing liver-related morbidity and cardiovascular risk. Recent therapies, including Resmetirom, FGF21 analogs, and GLP-1 agonists, have shown promise. This network meta-analysis evaluates their comparative efficacy and safety.

METHODS

A literature search was conducted across PubMed, Scopus, Web of Science, and Cochrane Library. Included clinical trials addressed MASLD or MASH with Resmetirom, FGF21 analogs, or GLP-1 agonists. Statistical analyses used a random-effects model, calculating mean differences (MD) and relative risks (RR), with heterogeneity assessed using τ2, I2, and Q statistics.

RESULTS

MASH resolution was significantly higher for FGF21 (RR 4.84, 95% CI: 2.59 to 9.03), Resmetirom showed the most significant reduction in MRI-PDFF (MD -18.41, 95% CI: -23.60 to -13.22) and >30% fat reduction (RR 3.56, 95% CI: 2.41 to 5.26). Resmetirom significantly reduced ALT (MD -15.71, 95% CI: -23.30 to -8.13), AST (MD -12.28, 95% CI: -21.07 to -3.49), and GGT (MD -19.56, 95% CI: -34.68 to -4.44). FGF21 and GLP-1 also reduced these markers. Adverse events were significantly higher with Resmetirom (RR 1.47, 95% CI: 1.24 to 1.74), while GLP-1 and FGF21 showed non-significant trends towards increased risk.

CONCLUSIONS

Resmetirom and FGF21 show promise in treating MASLD and MASH, with Resmetirom particularly effective in reducing liver fat and improving liver enzymes. GLP-1 agonists also show benefits but to a lesser extent. Further long-term studies are needed to validate these findings and assess cost-effectiveness.

Mixed active metabolites of the SNP-6 series of novel compounds mitigate metabolic dysfunction-associated steatohepatitis and fibrosis: promising results from pre-clinical and clinical trials

BACKGROUND

Metabolic dysfunction-associated steatohepatitis (MASH) is a growing global health concern with no effective pharmacological treatments. SNP-630, a newly developed synthetic molecule with multiple mechanisms of action, and a mixture of two of its active metabolites (SNP-630-MS) inhibit CYP2E1 expression to prevent reactive oxygen species generation, thereby reducing the accumulation of hepatic triglycerides and lowering chemokine levels. This study investigated the SNP-630's potential to alleviate the liver injury in MASH and its efficacy in both a mouse model and patients with MASH to identify a drug candidate that targets multiple pathways implicated in MASH.

METHODS

SNP-630 and SNP-630-MS were separately administered to the MASH mouse model. The tolerability, safety, and efficacy of SNP-630-MS were also evaluated in 35 patients with MASH. The primary endpoint of the study was assessment of the changes in serum alanine aminotransferase (ALT) levels from baseline to week 12, while the secondary endpoints included the evaluation of liver inflammation, steatosis, and fibrosis parameters and markers.

RESULTS

SNP-630 treatment in mice improved inflammation, liver steatosis, and fibrosis compared with that in the MASH control group. Both SNP-630 and SNP-630-MS treatments markedly reduced ALT levels, hepatic triglyceride content, and the expression of inflammatory cytokines monocyte chemoattractant protein 1 and fibrotic collagen (i.e., Col1a1, Col3a1, and Timp1) in mice. In the clinical trial, patients treated with SNP-630-MS exhibited significant improvement in ALT levels at week 12 compared with baseline levels, with no reports of severe adverse events. This improvement in ALT levels surpassed that achieved with most other MASH candidates. SNP-630-MS demonstrated potential antifibrotic effects, as evidenced by a significant decrease in the levels of fibrogenesis-related biomarkers such as CCL4, CCL5, and caspase 3. Subgroup analysis using FibroScan measurements further indicated the efficacy of SNP-630-MS in ameliorating liver fibrosis.

CONCLUSIONS

SNP-630 and SNP-630-MS demonstrated favorable results in mice. SNP-630-MS showed excellent tolerability in mice and patients with MASH. Efficacy analyses indicated that SNP-630-MS improved liver steatosis and injury in patients with MASH, suggesting that SNP-630 and 630-MS are promising therapeutic options for MASH. Larger scale clinical trials remain warranted to assess the efficacy and safety of SNP-630 in MASH.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03868566. Registered 06 March 2019-Retrospectively registered, https://clinicaltrials.gov/study/NCT03868566.

An insight into the updated pharmacotherapy of metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals: a review

Metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals represents a distinctive subset of MASH. Current pharmacotherapies, for MASH as demonstrated in clinical trials, predominantly target obese patients with limited consideration for lean MASH. We aimed to systematically review the literature on the pharmacotherapy of lean MASH. We searched standard medical databases, such as PubMed, Embase, Scopus, Cochrane CENTRAL, and ClinicalTrials.gov to identify eligible studies published in English up to 31 December 2023 regarding the effect of pharmacological interventions in individuals with lean MASH. We have summarized the role of various drug classes including peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, vitamin E, farnesoid X receptor agonists, selective thyroid hormone receptor-β agonists, and selective cholesterol absorption inhibitors. Consequently, lifestyle interventions, encompassing dietary modifications, exercise, and weight loss particularly directed at visceral obesity or achieving a reduction in body weight are recommended for all non-obese individuals with MASH. A highlight on the only available treatment recommendation for lean MASH is also presented. The available evidence regarding the efficacy of various drugs for the treatment of lean MASH is limited. Conclusive evidence is warranted from clinical trials exclusively involving lean individuals with MASH.

Beneficial effects of MGL-3196 and BAM15 combination in a mouse model of fatty liver disease

BACKGROUND AND AIM

Metabolic dysfunction-associated steatohepatitis (MASH) is a metabolic disorder with limited treatment options. The thyroid hormone receptor (THR)-β agonist resmetirom/MGL-3196 (MGL) increases liver fat oxidation and has been approved for treating adult MASH. However, over 60% of patients receiving MGL treatment do not achieve MASH resolution. Therefore, we investigated the potential for combination therapy of MGL with the mitochondrial uncoupler BAM15 to improve fatty liver disease outcomes in the GAN mouse model of MASH.

METHODS

C57BL/6J male mice were fed GAN diet for 38 weeks before stratification and randomization to treatments including MGL, BAM15, MGL + BAM15, or no drug control for 8 weeks. Treatments were admixed in diet and mice were pair-fed to control for drug intake. Treatment effectiveness was assessed by body weight, body composition, energy expenditure, glucose tolerance, tissue lipid content, and histological analyses.

RESULTS

MGL + BAM15 treatment resulted in better efficacy versus GAN control mice than either monotherapy in the context of energy expenditure, liver fat loss, glucose control, and fatty liver disease activity score. Improvements in ALT, liver mass, and plasma cholesterol were primarily driven by MGL, while improvements in body fat were primarily driven by BAM15. No treatments altered liver fibrosis.

CONCLUSIONS

MGL + BAM15 treatment had overall better efficacy to improve metabolic outcomes in mice fed GAN diet than either monotherapy alone. These data warrant further investigation into combination therapies of THR-β agonists and mitochondrial uncouplers for the potential treatment of disorders related to fatty liver, obesity, and insulin resistance.

Unveiling Resmetirom: A systematic review and meta-analysis on its impact on liver function and safety in non-alcoholic steatohepatitis treatment

Background and Aim

The role of Resmetirom in non-alcoholic steatohepatitis (NASH) represents a promising therapeutic approach in addressing the growing global burden of liver disease. With NASH emerging as a leading cause of liver-related morbidity and mortality worldwide, there is an urgent need for effective treatments. Resmetirom, a selective thyroid hormone receptor-β agonist, offers potential benefits in improving liver histology and metabolic parameters in patients with NASH. This review examines the current evidence surrounding Resmetirom's role in NASH management.

Methods

A systematic review and meta-analysis was done by searching in Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE (including MEDLINE InProcess) (OvidSP), Web of Science, Embase (OvidSP), and Scopus databases. ROB2 Cochrane tool was used for assessing risk of bias in randomized controlled trials (RCTs). In the analysis, we used RevMan Cochrane software.

Results

The study showed that patients who were treated with Resmetirom had significantly lower low-density lipoprotein-cholesterol (LDL-C) levels (mean difference [MD] -10.45; 95% confidence interval [CI] -15.86 to -5.83; P < 0.001) and alanine aminotransferase (ALT) levels (MD -7.18; 95% CI -12.67 to -1.68; P = 0.01) as compared with those in the placebo group. The risk of adverse events including diarrhea [risk ratio (RR) 1.81; 95% CI 1.40 to 2.35; P < 0.001] and nausea (RR 1.72; 95% CI 1.31 to 2.27; P < 0.001) was significantly increased for the Resmetirom group as compared with the placebo group.

Conclusion

Resmetirom presents a promising therapeutic option for NASH, offering potential benefits in reducing liver fat content and improving histological outcomes. The encouraging results from clinical trials suggest that Resmetirom may address an unmet need in NASH management, providing hope for patients with this progressive liver disease. Further research and long-term studies are warranted to validate its efficacy and safety profile in larger patient populations.

Review of current and new drugs for the treatment of metabolic-associated fatty liver disease

In the past 3 decades, metabolic-associated fatty liver disease (MAFLD) has emerged as a widespread liver condition, with its global prevalence on the rise. It ranks as a leading contributor to hepatocellular carcinoma (HCC) and necessitates liver transplantation. Under the multiple parallel hits model, the pathogenesis of MAFLD stems from various liver stressors, notably nutrient overload and sedentary lifestyles. While medical management for MAFLD is well-established, encompassing non-pharmaceutical and pharmaceutical interventions, determining the most effective pharmaceutical therapy has remained elusive. This review discusses diabetic medications for MAFLD treatment, emphasizing recent studies and emerging drugs while reviewing other nondiabetic agents. Emerging evidence suggests that combination therapies hold promise for resolving MAFLD and metabolic steatohepatitis (MASH) while managing side effects. Ongoing trials play a pivotal role in elucidating the effects of mono, dual, and triple receptor agonists in individuals with MASH. With the rising burden of MAFLD/MASH and its severe consequences, the need for effective treatments is more pressing than ever. This review provides a comprehensive overview of the current landscape of pharmaceutical interventions for MAFLD and MASH, shedding light on the potential of newer drugs especially diabetic medications and the importance of ongoing research in this field.

Comparative efficacy of THR-β agonists, FGF-21 analogues, GLP-1R agonists, GLP-1-based polyagonists, and Pan-PPAR agonists for MASLD: A systematic review and network meta-analysis

AIMS

To compare the efficacy of thyroid hormone receptor beta (THR-β) agonists, fibroblast growth factor 21 (FGF-21) analogues, glucagon-like peptide-1 receptor agonists (GLP-1RAs), GLP-1-based polyagonists, and pan-peroxisome proliferator-activated receptor (Pan-PPAR) agonists in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

A database search for relevant randomized double-blind controlled trials published until July 11, 2024, was conducted. Primary outcomes were the relative change in hepatic fat fraction (HFF) and liver stiffness assessed non-invasively by magnetic resonance imaging proton density fat fraction and elastography. Secondary outcomes included histology, liver injury index, lipid profile, glucose metabolism, blood pressure, and body weight.

RESULTS

Twenty-seven trials (5357 patients with MASLD) were identified. For HFF reduction, GLP-1-based polyagonists were most potentially effective (mean difference [MD] -51.47; 95 % confidence interval [CI]: -68.25 to -34.68; surface under the cumulative ranking curve [SUCRA] 84.9) vs. placebo, followed by FGF-21 analogues (MD -47.08; 95 % CI: -58.83 to -35.34; SUCRA 75.5), GLP-1R agonists (MD -37.36; 95 % CI: -69.52 to -5.21; SUCRA 52.3) and THR-β agonists (MD -33.20; 95 % CI: -43.90 to -22.51; SUCRA 36.9). For liver stiffness, FGF-21 analogues were most potentially effective (MD -9.65; 95 % CI: -19.28 to -0.01; SUCRA 82.2) vs. placebo, followed by THR-β agonists (MD -5.79; 95 % CI: -9.50 to -2.09; SUCRA 58.2), and GLP-1RAs (MD -5.58; 95 % CI: -15.02 to 3.86; SUCRA 54.7). For fibrosis improvement in histology, GLP-1-based polyagonists were most potentially effective, followed by FGF-21 analogues, THR-β agonists, Pan-PPAR agonists, and GLP-1R agonists; For MASH resolution in histology, GLP-1-based polyagonists were most potentially effective, followed by THR-β agonists, GLP-1R agonists, FGF-21 analogues, and Pan-PPAR agonists. THR-β agonists are well-balanced in liver steatosis and fibrosis, and excel at improving lipid profiles; FGF-21 analogues are effective at improving steatosis and particularly exhibit strong antifibrotic abilities. GLP-1R agonists showed significant benefits in improving liver steatosis, glucose metabolism, and body weight. GLP-1-based polyagonists have demonstrated the most potential efficacy overall in terms of comprehensive curative effect. Pan-PPAR agonists showed distinct advantages in improving liver function and glucose metabolism.

CONCLUSION

These results illustrate the relative superiority of the five classes of therapy in the treatment of MASLD and may serve as guidance for the development of combination therapies.

Anti-Inflammatory Oxysterol, Oxy210, Inhibits Atherosclerosis in Hyperlipidemic Mice and Inflammatory Responses of Vascular Cells

BACKGROUND AND AIMS

We previously reported that Oxy210, an oxysterol-based drug candidate, exhibits antifibrotic and anti-inflammatory properties. We also showed that, in mice, it ameliorates hepatic hallmarks of non-alcoholic steatohepatitis (NASH), including inflammation and fibrosis, and reduces adipose tissue inflammation. Here, we aim to investigate the effects of Oxy210 on atherosclerosis, an inflammatory disease of the large arteries that is linked to NASH in epidemiologic studies, shares many of the same risk factors, and is the major cause of mortality in people with NASH.

METHODS

Oxy210 was studied in vivo in APOE*3-Leiden.CETP mice, a humanized mouse model for both NASH and atherosclerosis, in which symptoms are induced by consumption of a high fat, high cholesterol "Western" diet (WD). Oxy210 was also studied in vitro using two cell types that are important in atherogenesis: human aortic endothelial cells (HAECs) and macrophages treated with atherogenic and inflammatory agents.

RESULTS

Oxy210 reduced atherosclerotic lesion formation by more than 50% in hyperlipidemic mice fed the WD for 16 weeks. This was accompanied by reduced plasma cholesterol levels and reduced macrophages in lesions. In HAECs and macrophages, Oxy210 reduced the expression of key inflammatory markers associated with atherosclerosis, including interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand 2 (CCL2), vascular cell adhesion molecule-1 (VCAM-1), and E-Selectin. In addition, cholesterol efflux was significantly enhanced in macrophages treated with Oxy210.

CONCLUSIONS

These findings suggest that Oxy210 could be a drug candidate for targeting both NASH and atherosclerosis, as well as chronic inflammation associated with the manifestations of metabolic syndrome.

Decreases in cT1 and liver fat content reflect treatment-induced histological improvements in MASH

BACKGROUND & AIMS

MRI biomarkers of liver disease are robust and reproducible alternatives to liver biopsy. Emerging data suggest that absolute reduction in iron corrected T1 (cT1) of ≥ 80 ms and relative reduction in liver fat content of 30% reflect histological improvement. We aimed to validate the associations of changes to these noninvasive biomarkers with histological improvement, specifically the resolution of steatohepatitis.

METHODS

A retrospective analysis of participants from three interventional clinical trials who underwent multiparametric MRI to measure liver cT1 and liver fat content (LFC) (LiverMultiScan) alongside biopsies at baseline and end of study. Responders were defined as those achieving resolution of steatohepatitis with no worsening in fibrosis. Differences in the magnitude of change in cT1 and LFC between responders and non-responders was assessed.

RESULTS

Individual patient data from 150 participants were included. There was a significant decrease in liver cT1 (-119 ms vs. -49 ms) and liver fat content (-65% vs. -29%) in responders compared to non-responders (P < .001) respectively. The diagnostic accuracy to identify responders was 0.72 (AUC) for both. The Youden's index for cT1 to separate responders from non-responders was -82 ms and for liver fat was a 58% relative reduction. Those achieving a ≥ 80 ms reduction in cT1 were 5-times more likely to achieve histological response (sens 0.68; spec 0.70). Those achieving a 30% relative reduction in liver fat were ∼4 times more likely to achieve a histological response (sens 0.77; spec 0.53).

CONCLUSIONS

These results, from three combined drug trials, demonstrate that changes in multiparametric MRI markers of liver health (cT1 and PDFF) can predict histological response for steatohepatitis following therapeutic intervention.

IMPACT AND IMPLICATIONS

There is great interest in identifying suitable biomarkers that can be used to replace liver biopsy, or to identify those patients who would benefit from one, in both the clinical management of MASH and in drug development. We investigated the utility of two MRI-derived non-invasive tests, iron corrected T1 mapping (cT1) and liver fat content from proton density fat fraction (PDFF), to predict histological improvement in patients who had undergone experimental treatment for MASH. Using data from 150 people who participated in one of three clinical trials, we observed that a reduction in cT1 by over 80 ms and a relative reduction in PDFF of over 58% were the optimal thresholds for change that predicted resolution of steatohepatitis. PDFF as a marker of liver fat, and cT1 as a specific measure of liver disease activity, are both effective at identifying those who are likely responding to drug interventions and experiencing improvements in overall liver health.

CLINICAL TRIAL NUMBER(S)

NCT02443116, NCT03976401, NCT03551522.

Discovery and Preclinical Profile of ALG-055009, a Potent and Selective Thyroid Hormone Receptor Beta (THR-β) Agonist for the Treatment of MASH

Agonists of thyroid hormone receptor β (THR-β) decreased LDL cholesterol (LDL-C) and triglyceride (TG) levels in human clinical trials for patients with dyslipidemia. The authors present the highly potent and selective compound ALG-055009 (14) as a potential best in class THR-β agonist. The high metabolic stability and good permeability translated well in vivo to afford a long in vivo half-life pharmacokinetic profile with limited liability for DDI, and it overcomes certain drawbacks seen in recent clinical candidates.

Comparison of wild-type and high-risk PNPLA3 variants in a human biomimetic liver microphysiology system for metabolic dysfunction-associated steatotic liver disease precision therapy

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a worldwide health epidemic with a global occurrence of approximately 30%. The pathogenesis of MASLD is a complex, multisystem disorder driven by multiple factors, including genetics, lifestyle, and the environment. Patient heterogeneity presents challenges in developing MASLD therapeutics, creating patient cohorts for clinical trials, and optimizing therapeutic strategies for specific patient cohorts. Implementing pre-clinical experimental models for drug development creates a significant challenge as simple in vitro systems and animal models do not fully recapitulate critical steps in the pathogenesis and the complexity of MASLD progression. To address this, we implemented a precision medicine strategy that couples the use of our liver acinus microphysiology system (LAMPS) constructed with patient-derived primary cells. We investigated the MASLD-associated genetic variant patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 (I148M variant) in primary hepatocytes as it is associated with MASLD progression. We constructed the LAMPS with genotyped wild-type and variant PNPLA3 hepatocytes, together with key non-parenchymal cells, and quantified the reproducibility of the model. We altered media components to mimic blood chemistries, including insulin, glucose, free fatty acids, and immune-activating molecules to reflect normal fasting (NF), early metabolic syndrome (EMS), and late metabolic syndrome (LMS) conditions. Finally, we investigated the response to treatment with resmetirom, an approved drug for metabolic syndrome-associated steatohepatitis (MASH), the progressive form of MASLD. This study, using primary cells, serves as a benchmark for studies using "patient biomimetic twins" constructed with patient induced pluripotent stem cell (iPSC)-derived liver cells using a panel of reproducible metrics. We observed increased steatosis, immune activation, stellate cell activation, and secretion of pro-fibrotic markers in the PNPLA3 GG variant compared to the wild-type CC LAMPS, consistent with the clinical characterization of this variant. We also observed greater resmetirom efficacy in the PNPLA3 wild-type CC LAMPS compared to the GG variant in multiple MASLD metrics, including steatosis, stellate cell activation, and the secretion of pro-fibrotic markers. In conclusion, our study demonstrates the capability of the LAMPS platform for the development of MASLD precision therapeutics, enrichment of patient cohorts for clinical trials, and optimization of therapeutic strategies for patient subgroups with different clinical traits and disease stages.

Spatial Transcriptomic Study Reveals Heterogeneous Metabolic Adaptation and a Role of Pericentral PPARα/CAR/Ces2a Axis During Fasting in Mouse Liver

Spatial heterogeneity and plasticity of the mammalian liver are critical for systemic metabolic homeostasis in response to fluctuating nutritional conditions. Here, a spatially resolved transcriptomic landscape of mouse livers across fed, fasted and refed states using spatial transcriptomics is generated. This approach elucidated dynamic temporal-spatial gene cascades and how liver zonation-both expression levels and patterns-adapts to shifts in nutritional status. Importantly, the pericentral nuclear receptor Nr1i3 (CAR) as a pivotal regulator of triglyceride metabolism is pinpointed. It is showed that the activation of CAR in the pericentral region is transcriptionally governed by Pparα. During fasting, CAR activation enhances lipolysis by upregulating carboxylesterase 2a, playing a crucial role in maintaining triglyceride homeostasis. These findings lay the foundation for future mechanistic studies of liver metabolic heterogeneity and plasticity in response to nutritional status changes, offering insights into the zonated pathology that emerge during liver disease progression linked to nutritional imbalances.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: Causation or Association

Nonalcoholic fatty liver disease (NAFLD) is a disease process that is gaining increasing recognition. The global prevalence of NAFLD is increasing in parallel with growing rates of risk factors for NAFLD such as hypertension, obesity, diabetes, and metabolic syndrome. NAFLD has been referred to as a risk factor for cardiovascular disease (CVD). As CVD is the leading cause of morbidity and mortality worldwide, there are constant efforts to describe and alleviate its risk factors. Although there is conflicting data supporting NAFLD as a causative or associative factor for CVD, NAFLD has been shown to be associated with structural, electrical, and atherosclerotic disease processes of the heart. Shared risk factors and pathophysiologic mechanisms between NAFLD and CVD warrant further explication. Pathologic mechanisms such as endothelial dysfunction, oxidative stress, insulin resistance, genetic underpinnings, and gut microbiota dysregulation have been described in both CVD and NAFLD. The mainstay of treatment for NAFLD is lifestyle intervention including physical exercise and hypocaloric intake in addition to bariatric surgery. Investigations into various therapeutic targets to alleviate hepatic steatosis and fibrosis by way of maintaining the balance between lipid synthesis and breakdown. A major obstacle preventing the success of many pharmacologic approaches has been the effects of these medications on CVD risk. The future of pharmacologic treatment of NAFLD is promising as effective medications with limited CVD harm are being investigated.

Esrra regulates Rplp1-mediated translation of lysosome proteins suppressed in metabolic dysfunction-associated steatohepatitis and reversed by alternate day fasting

OBJECTIVE

Currently, little is known about the mechanism(s) regulating global and specific protein translation during metabolic dysfunction-associated steatohepatitis (MASH; previously known as non-alcoholic steatohepatitis, NASH).

METHODS

Unbiased label-free quantitative proteome, puromycin-labelling and polysome profiling were used to understand protein translation activity in vitro and in vivo.

RESULTS

We observed a global decrease in protein translation during lipotoxicity in human primary hepatocytes, mouse hepatic AML12 cells, and livers from a dietary mouse model of MASH. Interestingly, proteomic analysis showed that Rplp1, which regulates ribosome and translation pathways, was one of the most downregulated proteins. Moreover, decreased Esrra expression and binding to the Rplp1 promoter, diminished Rplp1 gene expression during lipotoxicity. This, in turn, reduced global protein translation and Esrra/Rplp1-dependent translation of lysosome (Lamp2, Ctsd) and autophagy (sqstm1, Map1lc3b) proteins. Of note, Esrra did not increase its binding to these gene promoters or their gene transcription, confirming its regulation of their translation during lipotoxicity. Notably, hepatic Esrra-Rplp1-dependent translation of lysosomal and autophagy proteins also was impaired in MASH patients and liver-specific Esrra knockout mice. Remarkably, alternate day fasting induced Esrra-Rplp1-dependent expression of lysosomal proteins, restored autophagy, and reduced lipotoxicity, inflammation, and fibrosis in hepatic cell culture and in vivo models of MASH.

CONCLUSIONS

Esrra regulation of Rplp1-mediated translation of lysosome/autolysosome proteins was downregulated during MASH. Alternate day fasting activated this novel pathway and improved MASH, suggesting that Esrra and Rplp1 may serve as therapeutic targets for MASH. Our findings also provided the first example of a nuclear hormone receptor, Esrra, to not only regulate transcription but also protein translation, via induction of Rplp1.

Breakthrough in the Treatment of Metabolic Associated Steatotic Liver Disease: Is it all over?

On March 14, 2024, after more than 25 years of intense research and a long series of failures, the Food and Drug Administration approved resmetirom as first drug for the treatment of non-alcoholic steatohepatitis (NASH) with fibrosis (now Metabolic-Associated Steatotic Liver Disease - MASLD). The present review covers this difficult process, finally providing a drug to complement lifestyle intervention, that has long been the sole approved therapeutic intervention. However, the availability of a drug shown to reduce disease progression in advanced stages of diseases opens a series of questions that deserve even more intense research. How to continue ongoing trials? How to generate an appropriate use of resmetirom in the community, limiting treatment according to predefined criteria and according to individual risk assessment? How to guarantee that both hepatic and non-hepatic comorbidities are appropriately targeted? How to define cost-effective strategies that might prevent the generation of unacceptable differences within the population, given the high costs of novel drugs and the extremely high numbers of candidates to treatment? Only a close surveillance of drug use in the real world, generated by insurance databases and national healthcare system registries, might provide adequate answers to these compelling questions.

Efficacy and safety of resmetirom among patients with non-alcoholic steatohepatitis: a systematic review and meta-analysis

Background

Non-alcoholic steatohepatitis (NASH) is a severe medical illness that has few available therapeutic options. Resmetirom, a liver-targeting agonist of the thyroid hormone receptor (THR), has recently been licenced by the FDA. We assess the effectiveness and safety of resmetirom in patients with NASH.

Methods

PubMed, SCOPUS and Cochrane Central were searched till March 2024 to find potential articles. Outcomes assessed included MRI-proton density fat fraction (MRI-PDFF), Fat Reduction, and NASH Resolution Without Fibrosis, changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), low-density lipoprotein (LDL), and triglyceride (TG) levels, along with diarrhoea, nausea, urinary tract infection (UTI), and headache. Subgroup analysis was performed between outcomes before and after 6 months. Outcomes were analyzed with a random-effects model and results presented as mean difference (MD) for continuous outcomes and odds ratios (OR) for safety analysis, along with their 95% confidence intervals. A risk of bias assessment was performed using Cochrane Risk of Bias tool.

Results

Four randomized controlled trials (RCTs) were included in our analysis. Resmetirom shown a substantial improvement in MRI-PDFF with a MD of -19.23 (P<0.00001). Additionally, it resulted in a 30% reduction in fat (OR: 3.54, P=0.004) and resolution of NASH without fibrosis (OR: 2.41, P=0.04). There was no notable enhancement observed in AST levels, with a mean difference of -0.87 and a P value of 0.73. The usage of resmetirom resulted in significant improvement in ALT levels (MD: -4.36, P value: 0.32), GGT levels (MD: -17.87, P value: <0.00001), TG levels (MD: -23.48, P value: <0.00001), LDL levels (mean difference: -12.80, P value: <0.00001), and rT3 levels (MD: -2.08, P value: <0.00001). The use of Resmetirom was associated with a higher likelihood of experiencing diarrhoea (OR: 2.07, P<0.0001) and nausea (OR: 1.81, P=0.0003). However, there was no significant difference observed in the occurrence of UTI (OR: 1.04, P=0.85) or headaches (OR: 0.79, P=0.48).

Conclusion

Resmetirom demonstrates efficacy in enhancing MRI-PDFF score, diminishing adipose tissue, resolving NASH without fibrosis, reducing GGT, TG, LDL, reverse triiodothyronine (rT3) levels in NASH patients. Nevertheless, there is also an observed heightened susceptibility to experiencing diarrhoea and nausea. Additional trials are necessary to further examine the efficacy and safety of this medication.

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.

Efficacy and safety of Resmetirom, a selective thyroid hormone receptor-β agonist, in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD): a systematic review and meta-analysis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an important public health problem owing to its high prevalence and associated morbidity and mortality secondary to progressive liver disease and cardiovascular events. Resmetirom, a selective thyroid hormone receptor-β agonist has been developed as a therapeutic modality for MASLD. This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of resmetirom compared to a placebo in the treatment of MASLD. Eligible studies were systematically identified by screening PubMed, Scopus, Web of Science, Cochrane library, Embase, and ClinicalTrials.gov from 2014 to 2024. Only randomized controlled trials comparing the efficacy and safety of resmetirom in the treatment of MASLD against placebo were included in the analysis. Meta-analysis was performed using RevMan 5.4 software. Four studies with low risk of bias and involving a total of 2359 participants were identified. The metanalysis included only three clinical trials with 2234 participants. A significant reduction in MRI-proton density fat fraction (MRI-PDFF) with 80 mg Resmetirom compared to that with placebo [SMD - 27.74 (95% CI - 32.05 to - 32.42), p < 0.00001] at 36-52 weeks as well as at 12-16 weeks [SMD - 30.92 (95% CI - 36.44 to - 25.40), p < 0.00001]. With Resmetirom 100 mg dose at 36-52 weeks [SMD - 36.05 (95% CI - 40.67 to - 31.43), p < 0.00001] and 12-16 weeks [SMD - 36.89 (95% CI - 40.73 to - 33.05), p < 0.00001] were observed. Resmetirom treatment was associated with a significant reduction in LDL-c triglyceride, lipoproteins. and liver enzymes. There was significant reduction FT4 and increase in SHBG and sex steroids with Resmetirom compared to placebo. There was no major difference in the overall treatment emergent adverse events at 80 mg [OR 1.55 (95% CI 0.84 to 2.87), and 100 mg [OR 1.13 (95% CI 0.78 to 1.63), doses of Resmetirom compared to placebo. However, gastrointestinal adverse events diarrhoea and nausea occurred in ≥ 10% in the Resmetirom group compared to placebo at < 12 week. Resmetirom treatment showed modest efficacy in treating MASLD with reduction in MRI-PDFF, LDL-c, triglyceride, lipoproteins, liver enzymes and NASH biomarkers without significant safety concerns. Larger and long-term RCTs may further confirm this promising outcomes of Resmetirom use in MASLD.

Thyroid hormone receptor-beta agonist HSK31679 alleviates MASLD by modulating gut microbial sphingolipids

BACKGROUND & AIMS

As the first approved medication for metabolic dysfunction-associated steatohepatitis (MASH), the thyroid hormone receptor-β (THR-β) agonist MGL-3196 (resmetirom) has garnered much attention as a liver-directed, bioactive oral drug. However, studies on MGL-3196 have also identified remarkable heterogeneity of individual clinical efficacy and its interference with gut microbiota in host hepatoenteral circulation remains to be elucidated.

METHODS

We compared MASH attenuation by MGL-3196 and its derivative drug HSK31679 between germ-free (GF) and specific-pathogen free (SPF) mice to evaluate the role of gut microbiota. Then cross-omics analyses of microbial metagenome, metabolome and single-cell RNA-sequencing were applied to a randomized, double-blind, placebo-controlled multiple ascending dose cohort receiving HSK31679 treatment (n = 32) or placebo (n = 8), to comprehensively investigate the altered gut microbiota metabolism and circulating immune signatures.

RESULTS

HSK31679 outperformed MGL-3196 in ameliorating MASH diet-induced steatohepatitis of SPF mice but not GF mice. In the multiple ascending dose cohort of HSK31679, the relative abundance of B. thetaiotaomicron was significantly enriched, impairing glucosylceramide synthase (GCS)-catalyzed monoglucosylation of microbial Cer(d18:1/16:0) and Cer(d18:1/24:1). In contrast to the non-inferior effect of MGL-3196 and HSK31679 on MASH resolution in GFBTΔGCS mice, HSK31679 led to superior benefit on steatohepatitis in GFBTWT mice, due to its steric hindrance of R123 and Y401 of gut microbial GCS. For participants with high fecal GCS activity, the administration of 160 mg HSK31679 induced a shift in peripheral compartments towards an immunosuppressive niche, characterized by decreased CD8α+ dendritic cells and MINCLE+ macrophages.

CONCLUSIONS

This study provided novel insights into the gut microbiota that are key to the efficacy of HSK31679 treatment, revealing microbial GCS as a potential predictive biomarker in MASH, as well as a new target for further microbiota-based treatment strategies for MASH.

IMPACT AND IMPLICATIONS

Remarkable heterogeneity in individual clinical efficacy of thyroid hormone receptor-β agonists and their interferences with the microbiome in host hepatoenteral circulation are poorly understood. In our current germ-free mouse models and a randomized, double-blind, multiple-dose cohort study, we identified microbial glucosylceramide synthase as a key mechanistic node in the resolution of metabolic dysfunction-associated steatohepatitis. Microbial glucosylceramide synthase activity could be a predictive biomarker of response to HSK31679 treatment or a new target for microbiota-based therapeutics in metabolic dysfunction-associated steatohepatitis.

Pathophysiological Relationship between Type 2 Diabetes Mellitus and Metabolic Dysfunction-Associated Steatotic Liver Disease: Novel Therapeutic Approaches

Type 2 diabetes mellitus (T2DM), often featuring hyperglycemia or insulin resistance, is a global health concern that is increasing in prevalence in the United States and worldwide. A common complication is metabolic dysfunction-associated steatotic liver disease (MASLD), the hepatic manifestation of metabolic syndrome that is also rapidly increasing in prevalence. The majority of patients with T2DM will experience MASLD, and likewise, individuals with MASLD are at an increased risk for developing T2DM. These two disorders may act synergistically, in part due to increased lipotoxicity and inflammation within the liver, among other causes. However, the pathophysiological mechanisms by which this occurs are unclear, as is how the improvement of one disorder can ameliorate the other. This review aims to discuss the pathogenic interactions between T2D and MASLD, and will highlight novel therapeutic targets and ongoing clinical trials for the treatment of these diseases.

Impact of peripheral thyroid hormone balance on liver fat: insights from the NutriAct trial

OBJECTIVE

Hypothyroidism has been proposed as a potential contributor to steatotic liver disease (SLD), but existing data shows conflicting results in euthyroid subjects. Therefore, we investigated the association between thyroid function and intrahepatic lipids (IHLs) during a 36-month randomized controlled trial evaluating a diet known to reduce liver fat.

DESIGN

502 eligible subjects (aged 50-80 years, ≥1 risk factor for unhealthy aging) were randomly assigned to either follow a diet rich in unsaturated fatty acids, plant protein, and fiber (intervention group, IG), or dietary recommendations of the German Nutrition Society (control group, CG).

METHODS

Serum levels of thyroid hormones (THs) as well as IHLs, defined via magnetic resonance spectroscopy, were measured within an euthyroid subgroup without significant alcohol consumption at baseline (n = 332) and after 12 months (n = 243). A ratio of T3/T4 was used to assess whole-body deiodinase activity. Estimates of glucose and lipid metabolism were analyzed.

RESULTS

Only fT3 and T3/T4 ratios showed a significant positive correlation with IHL at baseline. We observed a significant decline in fT3, T3, fT3/fT4 ratio, and T3/T4 ratio in CG and IG after 12 months without significant differences between groups. TSH, fT4, and T4 remained stable. A larger improvement of IHL during dietary intervention was seen in those subjects with a lower decline in T3 concentrations.

CONCLUSIONS

Altered TH balance indicates a possible compensatory upregulation of whole-body TH activity in subjects with increased liver fat. This might be also relevant during the improvement of hepatic steatosis.

Letter: Boosting non-invasive tests-Opportunities and challenges from resmetirom

This article is linked to Harrison et al paper. To view this article, visit https://doi.org/10.1111/apt.17734

Obesity and MASLD: Is weight loss the (only) key to treat metabolic liver disease?

Metabolic dysfunction-associated steatotic liver disease (MASLD) closely associates with obesity and type 2 diabetes. Lifestyle intervention and bariatric surgery aiming at substantial weight loss are cornerstones of MASLD treatment by improving histological outcomes and reducing risks of comorbidities. Originally developed as antihyperglycemic drugs, incretin (co-)agonists and SGLT2 inhibitors also reduce steatosis and cardiorenovascular events. Certain incretin agonists effectively improve histological features of MASLD, but not fibrosis. Of note, beneficial effects on MASLD may not necessarily require weight loss. Despite moderate weight gain, one PPARγ agonist improved adipose tissue and MASLD with certain benefit on fibrosis in post-hoc analyses. Likewise, the first THRβ-agonist was recently provisionally approved because of significant improvements of MASLD and fibrosis. We here discuss liver-related and metabolic effects induced by different MASLD treatments and their association with weight loss. Therefore, we compare results from clinical trials on drugs acting via weight loss (incretin (co)agonists, SGLT2 inhibitors) with those exerting no weight loss (pioglitazone; resmetirom). Furthermore, other drugs in development directly targeting hepatic lipid metabolism (lipogenesis inhibitors, FGF21 analogs) are addressed. Although THRβ-agonism may effectively improve hepatic outcomes, MASLD treatment concepts should consider all cardiometabolic risk factors for effective reduction of morbidity and mortality in the affected people.

Dissecting Acute Drug-Induced Hepatotoxicity and Therapeutic Responses of Steatotic Liver Disease Using Primary Mouse Liver and Blood Cells in a Liver-On-A-Chip Model

Metabolic dysfunction-associated steatotic liver disease (MASLD) is hallmarked by hepatic steatosis, cell injury, inflammation, and fibrosis. This study elaborates on a multicellular biochip-based liver sinusoid model to mimic MASLD pathomechanisms and investigate the therapeutic effects of drug candidates lanifibranor and resmetirom. Mouse liver primary hepatocytes, hepatic stellate cells, Kupffer cells, and endothelial cells are seeded in a dual-chamber biocompatible liver-on-a-chip (LoC). The LoC is then perfused with circulating immune cells (CICs). Acetaminophen (APAP) and free fatty acids (FFAs) treatment recapitulate acute drug-induced liver injury and MASLD, respectively. As a benchmark for the LoC, multiplex immunofluorescence on livers from APAP-injected and dietary MASLD-induced mice reveals characteristic changes on parenchymal and immune cell populations. APAP exposure induces cell death in the LoC, and increased inflammatory cytokine levels in the circulating perfusate. Under FFA stimulation, lipid accumulation, cellular damage, inflammatory secretome, and fibrogenesis are increased in the LoC, reflecting MASLD. Both injury conditions potentiate CIC migration from the perfusate to the LoC cellular layers. Lanifibranor prevents the onset of inflammation, while resmetirom decreases lipid accumulation in hepatocytes and increases the generation of FFA metabolites in the LoC. This study demonstrates the LoC potential for functional and molecular evaluation of liver disease drug candidates.

Application and research progress of magnetic resonance proton density fat fraction in metabolic dysfunction-associated steatotic liver disease: a comprehensive review

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), formerly known as Non-Alcoholic Fatty Liver Disease (NAFLD), is a chronic liver disorder associated with disturbances in lipid metabolism. The disease is prevalent worldwide, particularly closely linked with metabolic syndromes such as obesity and diabetes. Magnetic Resonance Proton Density Fat Fraction (MRI-PDFF), serving as a non-invasive and highly quantitative imaging assessment tool, holds promising applications in the diagnosis and research of MASLD. This paper aims to comprehensively review and summarize the applications and research progress of MRI-PDFF technology in MASLD, analyze its strengths and challenges, and anticipate its future developments in clinical practice.

Effect of pemvidutide, a GLP-1/glucagon dual receptor agonist, on MASLD: A randomized, double-blind, placebo-controlled study

BACKGROUND & AIMS

This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

Patients with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus. The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment.

RESULTS

Ninety-four patients were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of patients had type 2 diabetes mellitus. At week 12, relative reductions in LFC from baseline were 46.6% (95% CI -63.7 to -29.6), 68.5% (95% CI -84.4 to -52.5), and 57.1% (95% CI -76.1 to -38.1) for the pemvidutide 1.2 mg, 1.8 mg, and 2.4 mg groups, respectively, vs. 4.4% (95% CI -20.2 to 11.3) for the placebo group (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of patients achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events.

CONCLUSIONS

In patients with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo.

IMPACT AND IMPLICATIONS

Metabolic dysfunction-associated steatotic liver disease, and its progressive form steatohepatitis, are strongly associated with overweight/obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/glucagon receptor agonist, to significantly reduce liver fat content, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both metabolic dysfunction-associated steatohepatitis and obesity.

CLINICAL TRIAL NUMBER

NCT05006885.

New advances in drug development for metabolic dysfunction-associated diseases and alcohol-associated liver disease

Metabolic disorders are currently threatening public health worldwide. Discovering new targets and developing promising drugs will reduce the global metabolic-related disease burden. Metabolic disorders primarily consist of lipid and glucose metabolic disorders. Specifically, metabolic dysfunction-associated steatosis liver disease (MASLD) and alcohol-associated liver disease (ALD) are two representative lipid metabolism disorders, while diabetes mellitus is a typical glucose metabolism disorder. In this review, we aimed to summarize the new drug candidates with promising efficacy identified in clinical trials for these diseases. These drug candidates may provide alternatives for patients with metabolic disorders and advance the progress of drug discovery for the large disease burden.

Emerging targets for therapy in ALD: Lessons from NASH

Alcohol-associated liver disease due to harmful alcohol use and NAFLD associated with metabolic syndrome are the 2 most common liver diseases worldwide. Control of respective risk factors is the cornerstone in the long-term management of these diseases. Furthermore, there are no effective therapies. Both diseases are characterized by metabolic derangements; thus, the focus of this review was to broaden our understanding of metabolic targets investigated in NAFLD, and how these can be applied to alcohol-associated liver disease. Conserved pathogenic pathways such as dysregulated lipid metabolism, cell death pathways including apoptosis and activation of innate immune cells, and stellate cells mediate both alcohol and NAFLDs, resulting in histological abnormalities of steatosis, inflammation, fibrosis, and cirrhosis. However, pathways such as gut microbiome changes, glucose metabolism and insulin resistance, inflammatory signaling, and microRNA abnormalities are distinct in these 2 diseases. In this review article, we describe conserved and distinct pathogenic pathways highlighting therapeutic targets that may be of potential in both diseases and those that are unique to each disease.

The first MASH drug therapy on the horizon: Current perspectives of resmetirom

The rising prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) poses a significant global health challenge, affecting over 30% of adults worldwide. MASLD is linked to increased mortality rates and substantial healthcare costs, primarily driven by its progression to metabolic dysfunction-associated steatohepatitis (MASH), which can lead to severe liver complications including cirrhosis and hepatocellular carcinoma. Despite its growing burden, effective pharmacotherapy for MASLD/MASH has been lacking until the recent conditional approval of resmetirom by the FDA. Resmetirom, a liver-targeted thyroid hormone receptor-β selective drug, has shown promise in clinical trials for treating non-cirrhotic MASH with moderate to advanced fibrosis. It has demonstrated efficacy in reducing hepatic fat content, improving liver histology (both MASH resolution and fibrosis improvement), and ameliorating biomarkers of liver damage without significant effects on body weight or glucose metabolism. Notably, resmetirom also exhibits favourable effects on circulating lipids, potentially reducing cardiovascular risk in MASLD/MASH patients. The safety profile of resmetirom appears acceptable, with gastrointestinal adverse events being the most common, though generally mild or moderate. However, long-term surveillance is warranted to monitor for potential risks related to thyroid, gonadal, or bone diseases. Clinical implementation of resmetirom faces challenges in patient selection and monitoring treatment response, and will heavily rely on non-invasive tests for liver fibrosis assessment. Nonetheless, resmetirom represents a landmark breakthrough in MASLD/MASH treatment, paving the way for future therapeutic strategies aiming to mitigate the multifaceted risks associated with this complex metabolic liver disease.

Randomised clinical trial: Design of the SYNERGY-NASH phase 2b trial to evaluate tirzepatide as a treatment for metabolic dysfunction-associated steatohepatitis and modification of screening strategy to reduce screen failures

BACKGROUND

The use of histological inclusion criteria for clinical trials of at-risk metabolic dysfunction-associated steatohepatitis (MASH) is often associated with high screen failure rates.

AIMS

To describe the design of a trial investigating tirzepatide treatment of MASH and to examine the effect of new inclusion criteria incorporating the use of the FibroScan-AST (FAST) score on the proportion of patients meeting histological criteria.

METHODS

SYNERGY-NASH is a Phase 2b, multicentre, randomised, double-blinded, placebo-controlled trial in patients with biopsy-confirmed MASH, F2-F3 fibrosis and NAFLD Activity Score ≥4. New inclusion criteria (FAST score >0.35 and an increase in AST inclusion criterion from >20 to >23 U/L) were adopted during the trial, allowing us to examine its impact on the qualification rate.

RESULTS

1583 participants were screened, 651 participants proceeded to liver biopsy and 190 participants were randomised with an overall screen fail rate of 87%. Following the protocol amendment, the overall qualification rate for per-protocol biopsies was minimally changed from 27.5% to 28.9% with considerable variation among different investigator medical speciality types: endocrinology: from 37.5% to 39.3%; gastroenterology/hepatology: from 26.0% to 23.3%; other specialities: from 21.3% to 29.7%. At 29 sites that performed per-protocol biopsies before and after the amendment, qualification rates changed as follows: all: 26.1% to 29.1%; endocrinology: from 35.0% to 40.9%; gastroenterology/hepatology: 25.6% to 20.0%; other specialities: from 16.1% to 27.8%.

CONCLUSIONS

For at-risk MASH trials based on liver histology, the implementation of inclusion criteria with the proposed FAST score and AST cut-offs in this trial was most effective at non-specialist sites.

Role of Resmetirom, a Liver-Directed, Thyroid Hormone Receptor Beta-Selective Agonist, in Managing Nonalcoholic Steatohepatitis: A Systematic Review and Meta-Analysis

BACKGROUND

Resmetirom, a liver-directed, thyroid hormone receptor beta-selective agonist, has recently been approved to treat nonalcoholic steatohepatitis (NASH). This meta-analysis aimed to summarize the efficiency and safety of resmetirom in treating NASH.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) of resmetirom vs placebo in patients with NASH. The primary outcomes were the changes from baseline in hepatic fat content, liver histology, including NASH resolution, and noninvasive markers of hepatic fibrosis.

RESULTS

Three randomized controlled trials (n = 2231) met the inclusion criteria. Compared to placebo, resmetirom achieved greater reductions from baseline in hepatic fat content assessed by magnetic resonance imaging proton density fat fraction (for resmetirom 80 mg: MD -27.76% [95%CI: -32.84, -22.69]; for resmetirom 100 mg: MD -36.01% [95%CI: -41.54, -30.48]; P < .00001 for both) and FibroScan controlled attenuation parameter (for resmetirom 80 mg: MD -21.45 dBm [95%CI: -29.37, -13.52]; for resmetirom 100 mg: MD -25.51 dBm [95%CI: -33.53, -17.49]; P < .00001 for both). Resmetirom 80 mg outperformed placebo in NASH resolution and ≥2-point nonalcoholic fatty liver disease activity score reduction. Moreover, resmetirom 80 mg and 100 mg were superior to placebo in cytokeratin-18 (M30) reduction. Greater reductions in liver enzymes, lipids, and reverse triiodothyronine were observed in the resmetirom arms with no impact on triiodothyronine. Nausea and diarrhea were more common with resmetirom than with placebo; other adverse events were comparable.

CONCLUSION

Resmetirom improves hepatic fat content, liver enzymes, and fibrosis biomarkers in NASH patients. Resmetirom generally does not affect thyroid function and is well-tolerated.

Efficacy of pharmacologic interventions on magnetic resonance imaging biomarkers in patients with nonalcoholic fatty liver disease: systematic review and network meta-analysis

BACKGROUND AND AIM

Several agents are under investigation for nonalcoholic fatty liver disease (NAFLD). We assessed the comparative efficacy of pharmacologic interventions for patients with NAFLD focusing on magnetic resonance imaging (MRI) biomarkers.

METHODS

We searched Medline, Embase, and CENTRAL. We included randomized controlled trials of more than 12 weeks of intervention that recruited patients with biopsy-confirmed or MRI-confirmed NAFLD and assessed the efficacy of interventions on liver fat content (LFC) and fibrosis by means of MRI. We performed random-effects frequentist network meta-analyses and assessed confidence in our estimates using the CINeMA (Confidence in Network Meta-Analysis) approach.

RESULTS

We included 47 trials (8583 patients). Versus placebo, thiazolidinediones were the most efficacious for the absolute change in LFC, followed by vitamin E, fibroblast growth factor (FGF) analogs, and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with mean differences ranging from -7.46% (95% confidence interval [-11.0, -3.9]) to -4.36% (-7.2, -1.5). No differences between drug classes were evident. Patients receiving GLP-1 RAs or glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RAs were more likely to achieve ≥30% relative reduction in LFC. Among agents, efruxifermin produced the largest reduction in LFC compared to placebo [-13.5% (-18.5, -8.5)], followed by pioglitazone, while being superior to most interventions. The effect of interventions on magnetic resonance elastography assessed fibrosis was small and insignificant. The confidence in our estimates was low to very low.

CONCLUSIONS

Several drug classes may reduce LFC in patients with NAFLD without a significant effect on fibrosis; nevertheless, trial duration was small, and confidence in the effect estimates was low.

Integrating behavioral interventions into a holistic approach to metabolic dysfunction-associated steatotic liver disease

INTRODUCTION

The therapeutic landscape of Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is rapidly evolving with the FDA approval of resmetirom, the first authorized molecule to treat metabolic dysfunction-associated steatohepatitis. Clinical trials are investigating other promising molecules. However, this focus on pharmacotherapy may overshadow lifestyle interventions, which remain the cornerstone of MASLD management. A significant percentage of patients with MASLD struggle with an underlying eating disorder, often a precursor to obesity. The obesity pandemic, exacerbated by the increasing prevalence of binge eating, underscores the need for a psychological approach to address their common roots.

AREAS COVERED

We reviewed the current evidence on behavioral interventions for MASLD. Interventions such as self-monitoring, goal setting, and frequent counseling, have proven effective in achieving at least 5% weight loss. Cognitive behavioral therapy is the first-line treatment for eating disorders and has shown efficacy in treating binge eating and obesity. Further research is needed to establish the optimal behavioral therapy for MASLD, focusing on enhancing compliance and achieving sustained weight loss through diet and physical exercise.

EXPERT OPINION

The treatment of MASLD should not rely solely on pharmacotherapy targeting a single-organ manifestation. Instead, we must consider behavioral interventions, emphasizing the pivotal role of a holistic approach to this multifaceted disorder. [Figure: see text].

Safety and efficacy of resmetirom in the treatment of patients with non-alcoholic steatohepatitis and liver fibrosis: a systematic review and meta-analysis

Introduction

Non-alcoholic fatty liver disease (NAFLD), spanning from non-alcoholic steatohepatitis (NASH) to liver fibrosis, poses a global health challenge amid rising obesity and metabolic syndrome rates. Effective pharmacological treatments for NASH and liver fibrosis are limited.

Objective

This study systematically reviews and meta-analyzes the safety and efficacy of resmetirom, a selective thyroid hormone receptor-β agonist, in NASH and liver fibrosis treatment. By analyzing data from clinical trials, we aim to offer evidence-based recommendations for resmetirom's use in managing these conditions and identify avenues for future research.

Methods

Electronic databases (PubMed, Scopus, Science Direct, Google Scholar, ClinicalTrials.gov, and Cochrane CENTRAL) were systematically searched, supplemented by manual screening of relevant sources. Only English-language randomized controlled trials were included. Data extraction, risk of bias assessment, pooled analyses, and meta-regression were performed.

Results

Three randomized controlled trials involving 2231 participants were analyzed. Resmetirom demonstrated significant reductions in hepatic fat fraction [standardized mean difference (SMD) -4.61, 95% CI -6.77 to -2.44, P < 0.0001], NASH resolution without worsening fibrosis [risk ratio (RR) 2.51, 95% CI 1.74-3.64, P = 0.00001), and liver fibrosis improvement (RR 2.31, 95% CI 1.20-4.44, P = 0.01). Secondary outcomes showed significant improvements in lipid profiles, liver enzymes, and NASH biomarkers with resmetirom treatment. Meta-regression revealed associations between covariates and primary outcomes.

Conclusion

Resmetirom exhibits promising efficacy in reducing hepatic fat, improving NASH resolution, and ameliorating liver fibrosis with a favorable safety profile. Further research is warranted to validate findings and optimize therapeutic strategies for NASH and liver fibrosis management.

Resmetirom: The First Food and Drug Administration-Approved Medication for Nonalcoholic Steatohepatitis (NASH)

OBJECTIVE

To review the literature leading to the Food and Drug Administration (FDA) approval of the first medication, resmetirom, for the treatment of nonalcoholic steatohepatitis (NASH), including the pharmacology, pharmacokinetics, clinical studies, dosing, and adverse effects. Relevant data will be used to discuss how resmetirom impacts clinical practice.

DATA SOURCES

A literature search was conducted using MEDLINE from database inception to May 12, 2024. Keywords included non-alcoholic steatohepatitis, nonalcoholic fatty liver disease, and resmetirom. Study selection, data extraction and all English-language studies involving the use of resmetirom for nonalcoholic fatty liver disease (NAFLD)/NASH were included.

DATA SYNTHESIS

Resmetirom, a thyroid hormone receptor agonist, is administered at daily doses of either 80 mg or 100 mg. The drug was shown to provide NASH resolution as assessed by the NAFLD activity score, 80 mg-24.2%, 100 mg-25.9% compared to 14.2% with the placebo group (P < 0.001). Resmetirom, improved liver fibrosis, 80 mg-25.9%, 100 mg-29.9% compared to 9.7% with the placebo group (P < 0.001). Resmetirom's ability to improve fibrosis in patients with F2-F3 fibrosis offers valuable benefit for patients at risk of progressing to cirrhosis.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Resmetirom expands the medication options available to treat patients with NASH which can be given alongside other medications to optimize metabolic factors such as glucagon-like peptide-1 and hydroxymethylglutaryl-coenzyme A reductase inhibitors. Resmetirom was well tolerated in studies.

CONCLUSION

Resmetirom serves as an attractive option in patients diagnosed with NASH with evidence of advanced fibrosis (F2-F3) in combination with exercise, diet, and other multimodal therapies targeting metabolic risk factors.

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

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.

Resmetirom: First Approval

Resmetirom (Rezdiffra™) is an oral thyroid hormone receptor-β (THR-β) agonist being developed by Madrigal Pharmaceuticals, Inc., to target the key underlying causes of metabolic dysfunction associated steatohepatitis (MASH) [previously known as nonalcoholic steatohepatitis (NASH)]. In March 2024, resmetirom was approved for use (under accelerated approval) in conjunction with diet and exercise for the treatment of adults with noncirrhotic NASH with moderate to advanced liver fibrosis (consistent with stages F2 to F3 fibrosis) in the USA. Resmetirom is also under regulatory review in the EU for the treatment of MASH/NASH. This article summarizes the milestones in the development of resmetirom leading to this first approval for the treatment of adults with MASH/NASH.