Expert Panel Recommendations: Practical Clinical Applications for Initiating and Monitoring Resmetirom in Patients With MASH/NASH and Moderate to Noncirrhotic Advanced Fibrosis

Clinical Insights on Resmetirom: Clinical Indications, Patient Selection, and Monitoring Response to Therapy

The recent conditional approval by the Food and Drug Administration of resmetirom for treating metabolic dysfunction-associated steatohepatitis (MASH) with significant or advanced fibrosis represents a pivotal milestone in the history of metabolic dysfunction-associated steatotic liver disease (MASLD) treatment. As the first liver-directed pharmacological therapy option for MASLD, resmetirom offers a novel approach that specifically targets liver pathology, marking a transformative step forward in managing this widespread and challenging condition. For initiating therapy with resmetirom, a liver biopsy is not required. Consequently, accurately excluding patients with less severe liver histology or cirrhosis using noninvasive tests (NITs) is essential. In addition, monitoring the therapy response should be conducted using NITs. Given the recent approval, our current clinical understanding of resmetirom is primarily informed by phase 3 clinical trials. The long-term effects of the drug should be evaluated in further studies by encouraging the use of the drug in eligible patients. This review highlights key aspects of clinical resmetirom use, including identifying the target population, monitoring therapeutic response, determining appropriate discontinuation criteria, and strategies to prevent unnecessary treatment interruptions.

Hepatic thyroid hormone receptor-β signalling: Mechanisms and recent advancements in the treatment of metabolic dysfunction-associated steatohepatitis

The pharmacotherapy of metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, the metabolic dysfunction-associated steatohepatitis (MASH), remains a hot topic in research and a largely unmet need in clinical practice. As the first approval of a disease-specific drug, resmetirom, was regarded as a milestone for the management of this common liver disease, this comprehensive and updated review aimed to highlight the importance of the hepatic thyroid hormone (TH) receptor (THR)-β signalling for the treatment of MASH, with a special focus on resmetirom. First, the genomic and non-genomic actions of the liver-directed THR-β mediated mechanisms are summarized. THR-β has a key role in hepatic lipid and carbohydrate metabolism; disruption of THR-β signalling leads to dysmetabolism, thus promoting MASLD and possibly its progression to MASH and cirrhosis. In the clinical setting, this is translated into a significant association between primary hypothyroidism and MASLD, as confirmed by recent meta-analyses. An association between MASLD and subclinical intrahepatic hypothyroidism (i.e. a state of relatively low hepatic triiodothyronine concentrations, with circulating TH concentrations within the normal range) is also emerging and under investigation. In line with this, the favourable results of the phase 3 placebo-controlled MAESTRO trials led to the recent conditional approval of resmetirom by the US FDA for treating adults with MASH and moderate-to-advanced fibrosis. This conditional approval of resmetirom opened a new window to the management of this common and burdensome liver disease, thus bringing the global scientific community in front of new perspectives and challenges.

Targeting PNPLA3 to Treat MASH and MASH Related Fibrosis and Cirrhosis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is caused by metabolic triggers and genetic predisposition. Among the genetic MASLD risk variants identified today, the common PNPLA3 148M variant exerts the largest effect size of MASLD heritability. The PNPLA3 148M protein is causatively linked to the development of liver steatosis, inflammation and fibrosis in experimental studies and is therefore an appealing target for therapeutic approaches to treat this disease. Several PNPLA3 targeted approaches are currently being evaluated in clinical trials for the treatment of metabolic dysfunction-associated steatohepatitis (MASH), the most severe form of MASLD and promising proof of principle data with reduced liver fat content in homozygous PNPLA3 148M risk allele carriers has been reported from phase 1 trials following hepatic silencing of PNPLA3. Thus, targeting PNPLA3, the strongest genetic determinant of MASH may hold promise as the first precision medicine for the treatment of this disease. A histological endpoint-based phase 2b study has been initiated and several more are expected to be initiated to evaluate treatment effects on histological MASH and liver fibrosis in participants being homozygous for the PNPLA3 148M risk allele variant. The scope of this mini-review is to briefly describe the PNPLA3 148M genetics, function and preclinical experimental evidence with therapeutic approaches targeting PNPLA3 as well as to summarise the PNPLA3 based therapies currently in clinical development.

Insights into the results of Resmetirom trials: Can a thyroid hormone receptor agonist be the holy grail of MASH therapy?

Despite the heavy individual patient and socioeconomic burden of metabolic dysfunction-associated steatohepatitis (MASH), until recently, no pharmacological therapy for MASH was approved, with available treatment options geared towards associated cardiometabolic risk factors. Accelerated approval of resmetirom, a thyroid hormone receptor-β agonist to be used in conjunction with diet and exercise, marks a significant step forward in the treatment of MASH, offering tempered optimism to healthcare providers and millions of patients around the world for more effective management. Evidence from phase 2 and 3 clinical trials suggests that resmetirom has the potential to alleviate hepatic fibrosis and inflammation and significantly reduce liver lipid content. Notwithstanding this landmark event, the clinical implementation of resmetirom comes with important challenges, for example, ensuring patient access to treatment and demonstrating effects on hard MASH-related outcomes, such as progression to cirrhosis and hepatocellular carcinoma. Additional considerations include the evaluation of co-administration with other hepatoprotective treatments and the assessment of the efficacy in specific MASH sub-phenotypes. Furthermore, the accumulation of real-world data and experience is expected to help answer the remaining questions about the (long-term) effectiveness and safety profile of the drug. The purpose of this article is to provide an updated and critical review of the mechanisms of action, efficacy, and safety of resmetirom based on the latest clinical trials, to define its place within the broader landscape of MASH management, and to highlight current knowledge gaps and opportunities for future research in the field.

Focused Recommendations for the Management of Metabolic Dysfunction-Associated Steatohepatitis (MASH) by Advanced Practice Providers in the United States

Metabolic dysfunction-associated steatohepatitis (MASH) has become the dominant cause of liver disease in the United States. With the growing burden of this disease in gastroenterology practices, the identification and treatment of those at risk of developing adverse outcomes (cirrhosis, hepatocellular carcinoma, or liver-related death) has become urgent. In recent years, the development of noninvasive tests (NITs) to identify "at-risk MASH" patients have provided cost-effective algorithms to identify these patients. Although treatment has historically been limited to lifestyle modification, recent FDA approval of resmetirom for noncirrhosis MASH with stages 2 and 3 fibrosis has provided a new opportunity in the United States to provide these patients with novel treatment options. Other new effective treatment regimens are on the horizon. Given that gastroenterology and hepatology practices in the United States heavily rely on advanced practice providers (APPs) to manage patients with MASLD, the APP Committee of the Global NASH/MASH Council has curated the essentials of day-to-day MASH management for our busy gastrohepatology providers and their APP colleagues. The goal of this document is to equip and mobilize more GI providers with the requisite competencies for the management of at-risk MASH, given the rapidly evolving MASH treatment landscape.

Design and rationale for a global novel non-invasive screening observational study using genetics and non-invasive methodologies to identify at-risk MASLD participants: The ALIGN study

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common chronic liver disease that is heterogenous in nature with various drivers and modifiers such as metabolic dysfunction and genetic factors. MASLD and the progressive subtype, metabolic dysfunction-associated steatohepatitis (MASH) represent the most rapidly increasing cause of liver-related mortality. There are limited treatment options for patients living with MASLD and MASH, various treatments with an array of different targets are under investigation and one therapeutic has been approved since the initiation of this study. Clinical trials investigating treatments for MASLD and MASH are associated with a high screen failure rate, driven largely by the regulatory required histological inclusion criteria for clinical trial eligibility. Other available clinically utilized biomarkers, typically referred to as non-invasive tests (NITs), can assess both the presence of steatosis and the severity of liver fibrosis in patients with MASLD and MASH in the clinic but are not yet approved over histological changes as endpoints for pivotal trials. However, the use of NITs have been demonstrated to increase the likelihood of meeting clinical trial entry criteria. All-Liver Interventional Global Network (ALIGN) is the first described multi-centre global observational screening study aimed at identifying individuals with a high likelihood of MASLD/MASH interested in participating in therapeutic clinical trials using non-invasive methodologies and genetic testing. This study represents a valuable prototype for industry and academic groups looking to evaluate large populations for MASH eligibility and interest in clinical trial participation.

Resmetirom: the first approved therapy for treating metabolic dysfunction associated steatohepatitis

INTRODUCTION

Metabolic dysfunction associated steatohepatitis (MASH), previously referred to as nonalcoholic steatohepatitis (NASH), has emerged as one of the leading indications for liver transplantation in the United States. The disease is associated with increased cardiovascular mortality in patients with early-stage liver fibrosis and a heightened risk of hepatic complications in those with advanced fibrosis. Despite its growing prevalence and significant healthcare burden, there were no approved drugs to treat this chronic disease. In March 2024, Resmetirom, a selective thyroid hormone receptor-beta agonist, became the first drug to receive FDA approval for the treatment of patients with MASH and fibrosis stages F2/F3. This accelerated approval was granted based on significantly higher rates of MASH resolution and fibrosis.

AREAS COVERED

This review summarizes the current literature on the mechanism of action, preclinical data, pharmacokinetics, clinical efficacy, indications, and contraindications of resmetirom in the management of patients with MASH.

EXPERT OPINION

The approval of resmetirom for patients with MASH and moderate to advanced hepatic fibrosis is a major advance in the management of MASH. The recent positive results of the ESSENCE trial of semaglutide, if associated with conditional approval, may offer clinicians two options to treat MASH in patients with moderate to advanced fibrosis.

Effect of high-intensity interval training on clinical parameters in patients with metabolic dysfunction-associated steatotic liver disease: a systematic review and meta-analysis of randomized controlled trials

High-intensity interval training (HIIT) has potential health benefits in the treatment of many chronic diseases. However, the efficacy of HIIT in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. This systematic review and meta-analysis aimed to assess the impact of HIIT on intrahepatic lipids (IHLs) , liver enzymes, and metabolic profiles in individuals with MASLD. All randomized-controlled trials (RCT) that evaluated and compared the effects of HIIT on clinical parameters in patients with MASLD were searched using the PubMed, EMBASE, WOS, and Cochrane databases. Data analysis and integration were performed using RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) and Stata version 18 software (StataCorp LLC, College Station, Texas, USA), and outcomes were assessed using the standardized mean difference (SMD). Our results showed that compared with other types of exercise or no exercise, HIIT could reduce the levels of IHL [SMD: -0.56%, 95% confidence interval (CI): -0.99 to -0.13, P = 0.01], BMI (SMD: -0.31, 95% CI: -0.62 to -0.01, P = 0.04), alanine aminotransferase (ALT) (SMD: -0.61, 95% CI: -0.95 to -0.26, P = 0.0006), and aspartate aminotransaminase (AST) (SMD: -0.43, 95% CI: -0.81 to -0.05, P = 0.03) in patients with MASLD. In addition, subgroup analyses showed that HIIT had a positive impact on clinical indicators in patients with MASLD with an intervention duration of less than equal to 8 weeks. This study supports the idea that HIIT can significantly reduce IHL, BMI, ALT, and AST levels, and further studies are needed to assess the long-term adherence and treatment effects of HIIT.

Metabolic dysfunction-associated steatotic liver disease in adults

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the umbrella term that comprises metabolic dysfunction-associated steatotic liver, or isolated hepatic steatosis, through to metabolic dysfunction-associated steatohepatitis, the progressive necroinflammatory disease form that can progress to fibrosis, cirrhosis and hepatocellular carcinoma. MASLD is estimated to affect more than one-third of adults worldwide. MASLD is closely associated with insulin resistance, obesity, gut microbial dysbiosis and genetic risk factors. The obesity epidemic and the growing prevalence of type 2 diabetes mellitus greatly contribute to the increasing burden of MASLD. The treatment and prevention of major metabolic comorbidities such as type 2 diabetes mellitus and obesity will probably slow the growth of MASLD. In 2023, the field decided on a new nomenclature and agreed on a set of research and action priorities, and in 2024, the US FDA approved the first drug, resmetirom, for the treatment of non-cirrhotic metabolic dysfunction-associated steatohepatitis with moderate to advanced fibrosis. Reliable, validated biomarkers that can replace histology for patient selection and primary end points in MASH trials will greatly accelerate the drug development process. Additionally, noninvasive tests that can reliably determine treatment response or predict response to therapy are warranted. Sustained efforts are required to combat the burden of MASLD by tackling metabolic risk factors, improving risk stratification and linkage to care, and increasing access to therapeutic agents and non-pharmaceutical interventions.

A Pragmatic Management Approach for Metabolic Dysfunction-Associated Steatosis and Steatohepatitis

Obesity and associated insulin resistance induce a chronic metaboinflammatory state that lead to injury and dysfunction of multiple organs resulting in a cluster of noncommunicable diseases such as type 2 diabetes mellitus, hypertension, cardiovascular disease, chronic kidney disease, and metabolic dysfunction-associated steatotic liver disease (MASLD). Metabolic dysfunction-associated steatohepatitis (MASH) is a histologically active form of MASLD and characterized by greater injury and inflammation and progresses to cirrhosis with greater certainty than steatosis alone. The progression to cirrhosis is characterized by increasing fibrosis. The goal of treatment of MASLD/MASH was to improve the metaboinflammatory state i.e., the root cause of the liver disease and to prevent fibrosis progression to cirrhosis whereas in those who already have cirrhosis need additional care to prevent portal hypertension-related outcomes. Fibrosis regression is thus a key objective of treatment. The recent approval of resmetirom for MASH with fibrosis and the use of glucagon-like peptide-1 receptor agonists for obesity and type 2 diabetes has increased awareness of these NCDs and resulted in the growing demand for liver assessment and care in obese individuals. Patients with MASLD also have multiple metabolic comorbidities which represent competing threats to life, and the care of the patient requires both assessment of the totality of the risk and a more holistic approach integrating the care of all of the threats to life. Here, we provide a pragmatic and easily implementable risk-based approach to the evaluation and management of MASLD.

Identification of Candidates for MASLD Treatment With Indeterminate Vibration-Controlled Transient Elastography

BACKGROUND AND AIMS

A noteworthy proportion of patients with metabolic dysfunction-associated steatotic liver disease (MASLD) have an indeterminate vibration-controlled transient elastography (VCTE). Among these patients, we aimed to identify candidates for MASLD treatment by diagnosing significant fibrosis.

METHODS

This was a real-world prospective study including a large dataset of MASLD patients with paired VCTE and liver biopsy from 6 centers. A total of 1196 patients were recruited and divided in training (3 centers, Spain), internal validation (2 centers, Spain), and external validation (1 center, United States) cohorts. In patients with indeterminate liver stiffness measurement (LSM) (8-12 kPa), a diagnostic algorithm was developed to identify significant fibrosis, defined as histological stage ≥F2. Statistical analysis was performed using Gaussian mixture model (GMM) and k-means unsupervised clusterization.

RESULTS

From the eligible population, 33%, 29%, and 31% had indeterminate VCTE in the training, internal and external validation samples, respectively. The controlled attenuation parameter allowed the differentiation of GMM clusters with a cutoff of 280 dB/m (area under the curve, 0.89; 95% confidence interval, 0.86-0.97). Within patients with <280 dB/m, a LSM between 8.0-9.0 kPa showed a 93% sensitivity and a 91% negative predictive value to exclude significant fibrosis. Among patients with ≥280 dB/m, a LSM between 10.3 and 12.0 kPa diagnosed significant fibrosis with a 91% specificity. Applying this algorithm to the validation cohorts, 36% of the indeterminate VCTE were reallocated. The reallocated high-risk group showed a prevalence of 86% significant fibrosis, opening the therapeutic window for MASLD patients.

CONCLUSIONS

To identify candidates for MASLD treatment among indeterminate VCTE, an algorithm-based on the sequential combination of LSM and controlled attenuation parameter thresholds can optimize the diagnosis of moderate-to-advanced fibrosis.

NAFLD No More: A Review of Current Guidelines in the Diagnosis and Evaluation of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

PURPOSE OF REVIEW

Provide a concise update on metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), as well as a practical approach to screening and initial evaluation.

RECENT FINDINGS

Nomenclature changes have placed a greater focus on cardiometabolic risk factors in the definition of MASLD. Screening for MASLD is by stepwise noninvasive serum and imaging tests which can identify patients at risk for advanced fibrosis and liver-related complications. MASLD has been increasing in prevalence and disease burden but is underrecognized in primary care and endocrinology clinics. Multiple society guidelines, synthesized here, provide a framework for the initial approach in the diagnosis and evaluation of MASLD. Recent advances in pharmacologic treatment underline the importance of screening for patients who are at risk for advanced fibrosis as they are most likely to benefit from new drug classes, such as the liver-directed thyroid receptor agonist resmiterom.

Significant Within-Individual Variability in VCTE Liver Stiffness Measurements at Two Intercostal Spaces in Subjects with MASLD: Implications for Evaluating Improvement in Liver Fibrosis After Weight-Loss or Liver-Directed Therapy

INTRODUCTION

Studies have compared the group-averages of liver stiffness measures (LSMs) from multiple rib spaces by vibration-controlled transient elastography (VCTE) to stage liver fibrosis. No previous study has assessed within-individual liver stiffness variation from two rib spaces in individuals with metabolic-dysfunction associated steatotic liver disease (MASLD).

METHODS

We evaluated within-individual LSM variation according to body weight classification and its clinical implication. From October 2019 to March 2024, VCTE was performed on MASLD patients or those at high risk, in accordance with FibroScan guidelines. The LSMs were categorized into stages: <5 kPa (stage 0), 5-7.99 kPa (stage 1), 8-9.99 kPa (stage 2), 10-13.99 kPa (stage 3), and 14+ kPa (stage 4). Measurements with 10 values and IQR/median ≤ 0.30 were included, using SPSS V25.0 for analysis.

RESULTS

Among 1107 subjects (age 54.4 ± 13.9 years, 56.9% female), 7.7% were normal weight, 20.7% overweight, 28.9% class 1 obesity, 21.3% class 2 obesity, and 21.2% class 3 obesity. Significant within-individual variation was noted: 67% (0-2 kPa) variation, 23.4% (2.1-6 kPa), and 10% (≥6.1 kPa). Class 3 obese individuals had the maximum variation. Comparing the group-average of LSM at each ICS site showed that 95% of individuals were within one fibrosis stage.

CONCLUSIONS

While LSM group-averages at different rib sites provides reliable fibrosis staging, significant within-individual variability exists especially in class 3 obesity. This should be considered when serial LSM assessments are used to assess medical therapeutic efficacy.

Effectiveness of Resmetirom in Reducing Cholesterol Levels in Patients With Nonalcoholic Steatohepatitis: A Systematic Review and Meta-Analysis

Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) associated with metabolic syndrome and increased cardiovascular risk. Resmetirom, a novel liver-directed selective thyroid hormone receptor-β (THR-β) agonist, has shown promise in addressing both hepatic and systemic lipid metabolism. This systematic review and meta-analysis aimed to evaluate the efficacy of resmetirom in improving cholesterol levels in NASH patients. A systematic literature search was conducted across multiple databases including PubMed, Embase, Cochrane Library, and ClinicalTrials.gov, identifying three randomized controlled trials for inclusion. The meta-analysis revealed that resmetirom significantly reduced low-density lipoprotein cholesterol (LDL-C) levels compared to placebo (MD: -23.62; 95% CI: -37.32 to -9.93; p < 0.001). Similarly, triglyceride (TG) levels showed a significant reduction in the resmetirom group (MD: -33.86; 95% CI: -47.79 to -19.92; p < 0.001). Importantly, there was no significant difference in the risk of serious adverse events between resmetirom and placebo groups (RR: 1.09; 95% CI: 0.73 to 1.63; p = 0.67). These findings suggest that resmetirom effectively improves lipid profiles in NASH patients without compromising safety. However, the analysis was limited by the small number of studies, all from the same research group, and high heterogeneity in results. Future research should include more diverse studies, longer follow-up periods, and cost-effectiveness evaluations. Despite these limitations, resmetirom shows promise as a potential treatment for managing dyslipidemia and cardiovascular risk in NASH patients, potentially influencing future treatment guidelines for both liver and cardiovascular health in this population.

Letter: Enhancing cirrhosis management-The critical role of social workers in supporting NAFLD surveillance: Authors' reply

This article is linked to Tran et al papers. To view these articles, visit https://doi.org/10.1111/apt.18024 and https://doi.org/10.1111/apt.18245.