Complexity of ballooned hepatocyte feature recognition: Defining a training atlas for artificial intelligence-based imaging in NAFLD

Natural history and progression of metabolic dysfunction-associated steatotic liver disease

The natural history of metabolic dysfunction-associated steatotic liver disease (MASLD), previously referred to as non-alcoholic fatty liver disease (NAFLD), is complex and long. A minority of patients develop inflammation and risk progressive fibrosis that can result in cirrhosis. Progression to cirrhosis occurs in 3-5% of patients and often takes more than 20 years. This narrative review presents an update on the natural history of MASLD, discussing studies and risk estimates for progression to severe outcomes, such as decompensated cirrhosis or hepatocellular carcinoma. We highlight the dynamic progression of liver damage, how to identify patients whose disease progresses over time, and how risk factors might be mitigated to reduce the risk for disease progression.

Ferroptosis is a targetable detrimental factor in metabolic dysfunction-associated steatotic liver disease

There is an unmet clinical need for pharmacologic treatment for metabolic dysfunction-associated steatotic liver disease (MASLD). Hepatocyte cell death is a hallmark of this highly prevalent chronic liver disease, but the dominant type of cell death remains uncertain. Here we report that ferroptosis, an iron-catalyzed mode of regulated cell death, contributes to MASLD. Unsupervised clustering in a cohort of biopsy-proven MASLD patients revealed a subgroup with hepatic ferroptosis signature and lower glutathione peroxidase 4 (GPX4) levels. Likewise, a subgroup with reduced ferroptosis defenses was discerned in public transcriptomics datasets. Four weeks of choline-deficient L-amino acid-defined high-fat diet (CDAHFD) induced MASLD with ferroptosis in mice. Gpx4 overexpression did not affect steatohepatitis, instead CDAHFD protected from morbidity due to hepatocyte-specific Gpx4 knockout. The ferroptosis inhibitor UAMC-3203 attenuated steatosis and alanine aminotransferase in CDAHFD and a second model, i.e., the high-fat high-fructose diet (HFHFD). The effect of monounsaturated and saturated fatty acids supplementation on ferroptosis susceptibility was assessed in human HepG2 cells. Fat-laden HepG2 showed a drop in ferroptosis defenses, increased phosphatidylglycerol with two polyunsaturated fatty acid (PUFA) lipid tails, and sustained ferroptosis sensitivity. In conclusion, this study identified hepatic ferroptosis as a detrimental factor in MASLD patients. Unexpectedly, non-PUFA supplementation to hepatocytes altered lipid bilayer composition to maintain ferroptosis sensitivity. Based on findings in in vivo models, ferroptosis inhibition represents a promising therapeutic target in MASLD.

AI-based automation of enrollment criteria and endpoint assessment in clinical trials in liver diseases

Clinical trials in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis) require histologic scoring for assessment of inclusion criteria and endpoints. However, variability in interpretation has impacted clinical trial outcomes. We developed an artificial intelligence-based measurement (AIM) tool for scoring MASH histology (AIM-MASH). AIM-MASH predictions for MASH Clinical Research Network necroinflammation grades and fibrosis stages were reproducible (κ = 1) and aligned with expert pathologist consensus scores (κ = 0.62-0.74). The AIM-MASH versus consensus agreements were comparable to average pathologists for MASH Clinical Research Network scores (82% versus 81%) and fibrosis (97% versus 96%). Continuous scores produced by AIM-MASH for key histological features of MASH correlated with mean pathologist scores and noninvasive biomarkers and strongly predicted progression-free survival in patients with stage 3 (P < 0.0001) and stage 4 (P = 0.03) fibrosis. In a retrospective analysis of the ATLAS trial (NCT03449446), responders receiving study treatment showed a greater continuous change in fibrosis compared with placebo (P = 0.02). Overall, these results suggest that AIM-MASH may assist pathologists in histologic review of MASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient responses.

Diagnostic accuracy of non-invasive tests to screen for at-risk MASH-An individual participant data meta-analysis

BACKGROUND & AIMS

There is a need to reduce the screen failure rate (SFR) in metabolic dysfunction-associated steatohepatitis (MASH) clinical trials (MASH+F2-3; MASH+F4) and identify people with high-risk MASH (MASH+F2-4) in clinical practice. We aimed to evaluate non-invasive tests (NITs) screening approaches for these target conditions.

METHODS

This was an individual participant data meta-analysis for the performance of NITs against liver biopsy for MASH+F2-4, MASH+F2-3 and MASH+F4. Index tests were the FibroScan-AST (FAST) score, liver stiffness measured using vibration-controlled transient elastography (LSM-VCTE), the fibrosis-4 score (FIB-4) and the NAFLD fibrosis score (NFS). Area under the receiver operating characteristics curve (AUROC) and thresholds including those that achieved 34% SFR were reported.

RESULTS

We included 2281 unique cases. The prevalence of MASH+F2-4, MASH+F2-3 and MASH+F4 was 31%, 24% and 7%, respectively. Area under the receiver operating characteristics curves for MASH+F2-4 were .78, .75, .68 and .57 for FAST, LSM-VCTE, FIB-4 and NFS. Area under the receiver operating characteristics curves for MASH+F2-3 were .73, .67, .60, .58 for FAST, LSM-VCTE, FIB-4 and NFS. Area under the receiver operating characteristics curves for MASH+F4 were .79, .84, .81, .76 for FAST, LSM-VCTE, FIB-4 and NFS. The sequential combination of FIB-4 and LSM-VCTE for the detection of MASH+F2-3 with threshold of .7 and 3.48, and 5.9 and 20 kPa achieved SFR of 67% and sensitivity of 60%, detecting 15 true positive cases from a theoretical group of 100 participants at the prevalence of 24%.

CONCLUSIONS

Sequential combinations of NITs do not compromise diagnostic performance and may reduce resource utilisation through the need of fewer LSM-VCTE examinations.

A Precision Medicine Guided Approach to the Utilization of Biomarkers in MASLD

The new nomenclature of metabolic dysfunction-associated steatotic liver disease (MASLD) emphasizes a positive diagnosis based on cardiometabolic risk factors. This definition is not only less stigmatizing but also allows for subclassification and stratification, thereby addressing the heterogeneity of what was historically referred to as nonalcoholic fatty liver disease. The heterogeneity within this spectrum is influenced by several factors which include but are not limited to demographic/dietary factors, the amount of alcohol use and drinking patterns, metabolic status, gut microbiome, genetic predisposition together with epigenetic factors. The net effect of this dynamic and intricate system-level interaction is reflected in the phenotypic presentation of MASLD. Therefore, the application of precision medicine in this scenario aims at complex phenotyping with consequent individual risk prediction, development of individualized preventive strategies, and improvements in the clinical trial designs. In this review, we aim to highlight the importance of precision medicine approaches in MASLD, including the use of novel biomarkers of disease, and its subsequent utilization in future study designs.

A roadmap for clinical trials in MASH-related compensated cirrhosis

Although metabolic dysfunction-associated steatohepatitis (MASH) is rapidly becoming a leading cause of cirrhosis worldwide, therapeutic options are limited and the number of clinical trials in MASH-related compensated cirrhosis is low as compared to those conducted in earlier disease stages. Moreover, designing clinical trials in MASH cirrhosis presents a series of challenges regarding the understanding and conceptualization of the natural history, regulatory considerations, inclusion criteria, recruitment, end points and trial duration, among others. The first international workshop on the state of the art and future direction of clinical trials in MASH-related compensated cirrhosis was held in April 2023 at Vall d'Hebron University Hospital in Barcelona (Spain) and was attended by a group of international experts on clinical trials from academia, regulatory agencies and industry, encompassing expertise in MASH, cirrhosis, portal hypertension, and regulatory affairs. The presented Roadmap summarizes important content of the workshop on current status, regulatory requirements and end points in MASH-related compensated cirrhosis clinical trials, exploring alternative study designs and highlighting the challenges that should be considered for upcoming studies on MASH cirrhosis.

Artificial intelligence scoring of liver biopsies in a phase II trial of semaglutide in nonalcoholic steatohepatitis

BACKGROUND AND AIMS

Artificial intelligence-powered digital pathology offers the potential to quantify histological findings in a reproducible way. This analysis compares the evaluation of histological features of NASH between pathologists and a machine-learning (ML) pathology model.

APPROACH AND RESULTS

This post hoc analysis included data from a subset of patients (n=251) with biopsy-confirmed NASH and fibrosis stage F1-F3 from a 72-week randomized placebo-controlled trial of once-daily subcutaneous semaglutide 0.1, 0.2, or 0.4 mg (NCT02970942). Biopsies at baseline and week 72 were read by 2 pathologists. Digitized biopsy slides were evaluated by PathAI's NASH ML models to quantify changes in fibrosis, steatosis, inflammation, and hepatocyte ballooning using categorical assessments and continuous scores. Pathologist and ML-derived categorical assessments detected a significantly greater percentage of patients achieving the primary endpoint of NASH resolution without worsening of fibrosis with semaglutide 0.4 mg versus placebo (pathologist 58.5% vs. 22.0%, p < 0.0001; ML 36.9% vs. 11.9%; p =0.0015). Both methods detected a higher but nonsignificant percentage of patients on semaglutide 0.4 mg versus placebo achieving the secondary endpoint of liver fibrosis improvement without NASH worsening. ML continuous scores detected significant treatment-induced responses in histological features, including a quantitative reduction in fibrosis with semaglutide 0.4 mg versus placebo ( p =0.0099) that could not be detected using pathologist or ML categorical assessment.

CONCLUSIONS

ML categorical assessments reproduced pathologists' results of histological improvement with semaglutide for steatosis and disease activity. ML-based continuous scores demonstrated an antifibrotic effect not measured by conventional histopathology.

Aramchol improves hepatic fibrosis in metabolic dysfunction-associated steatohepatitis: Results of multimodality assessment using both conventional and digital pathology

BACKGROUND AND AIMS

Antifibrotic trials rely on conventional pathology despite recognized limitations. We compared single-fiber digital image analysis with conventional pathology to quantify the antifibrotic effect of Aramchol, a stearoyl-CoA desaturase 1 inhibitor in development for metabolic dysfunction-associated steatohepatitis.

APPROACH AND RESULTS

Fifty-one patients with metabolic dysfunction-associated steatohepatitis enrolled in the open-label part of the ARMOR trial received Aramchol 300 mg BID and had paired pre-post treatment liver biopsies scored by consensus among 3 hepatopathologists, and separately assessed by a digital image analysis platform (PharmaNest) that generates a continuous phenotypic Fibrosis Composite Severity (Ph-FCS) score. Fibrosis improvement was defined as: ≥1 NASH Clinical Research Network (NASH-CRN) stage reduction; "improved" by ranked pair assessment; reduction in Ph-FCS ("any" for ≥0.3 absolute reduction and "substantial" for ≥25% relative reduction). Fibrosis improved in 31% of patients (NASH-CRN), 51% (ranked pair assessment), 74.5% (any Ph-FCS reduction), and 41% (substantial Ph-FCS reduction). Most patients with stable fibrosis by NASH-CRN or ranked pair assessment had a Ph-FCS reduction (a third with substantial reduction). Fibrosis improvement increased with treatment duration: 25% for <48 weeks versus 39% for ≥48 weeks by NASH-CRN; 43% versus 61% by ranked pair assessment, mean Ph-FCS reduction -0.54 (SD: 1.22) versus -1.72 (SD: 1.02); Ph-FCS reduction (any in 54% vs. 100%, substantial in 21% vs. 65%). The antifibrotic effect of Aramchol was corroborated by reductions in liver stiffness, Pro-C3, and enhanced liver fibrosis. Changes in Ph-FCS were positively correlated with changes in liver stiffness.

CONCLUSIONS

Continuous fibrosis scores generated in antifibrotic trials by digital image analysis quantify antifibrotic effects with greater sensitivity and a larger dynamic range than conventional pathology.

Envisioning how to advance the MASH field

Since 1980, the cumulative effort of scientists and health-care stakeholders has advanced the prerequisites to address metabolic dysfunction-associated steatotic liver disease (MASLD), a prevalent chronic non-communicable liver disease. This effort has led to, among others, the approval of the first drug specific for metabolic dysfunction-associated steatohepatitis (MASH; formerly known as nonalcoholic steatohepatitis). Despite substantial progress, MASLD is still a leading cause of advanced chronic liver disease, including primary liver cancer. This Perspective contextualizes the nomenclature change from nonalcoholic fatty liver disease to MASLD and proposes important considerations to accelerate further progress in the field, optimize patient-centric multidisciplinary care pathways, advance pharmacological, behavioural and diagnostic research, and address health disparities. Key regulatory and other steps necessary to optimize the approval and access to upcoming additional pharmacological therapeutic agents for MASH are also outlined. We conclude by calling for increased education and awareness, enhanced health system preparedness, and concerted action by policy-makers to further the public health and policy agenda to achieve at least parity with other non-communicable diseases and to aid in growing the community of practice to reduce the human and economic burden and end the public health threat of MASLD and MASH by 2030.

FAST and Agile-the MASLD drift: Validation of Agile 3+, Agile 4 and FAST scores in 246 biopsy-proven NAFLD patients meeting MASLD criteria of prevalent caucasian origin

BACKGROUND

MASLD is a prevalent chronic liver condition with substantial clinical implications. This study aimed to assess the effectiveness of three new, elastography-based, scoring systems for advanced fibrosis ≥F3 (Agile 3+), cirrhosis F4 (Agile 4), and fibrotic NASH: NASH + NAS ≥4 + F≥2 (FAST score), in a cohort of biopsy-proven NAFLD meeting MASLD criteria. Our secondary aim was to compare their diagnostic performances with those of other fibrosis prediction tools: LSM-VCTE alone, and common, easily available scores (FIB-4 or APRI).

METHODS

Single-center, retrospective study, on consecutive patients with baseline laboratory tests, liver biopsy, and reliable LSM-VCTE measurements. The discrimination between tests was evaluated by analyzing the AUROCs. Dual cut-off approaches were applied to rule-out and rule-in ≥F3, F4 and fibrotic NASH. We tested previously reported cut-off values and provided our best thresholds to achieve Se ≥85%, Se ≥90%, and Sp ≥90%, Sp ≥95%.

RESULTS

Among 246 patients, 113 (45.9%) were women, and 75 (30.5%) presented diabetes. Agile 3+ and Agile 4 demonstrated excellent performance in identifying ≥F3 and F4, achieving AUROCs of 0.909 and 0.968, while the FAST score yielded acceptable results in distinguishing fibrotic NASH. When compared to FIB-4 and LSM-VCTE, both Agile 3+ and Agile 4 performed better than FIB-4 and had a similar performance to LSM-VCTE, but with higher diagnostic accuracy, hence reducing the grey zone.

CONCLUSION

Agile 3+ and Agile 4 are reliable, non-invasive tests for identifying advanced fibrosis or cirrhosis in MASLD patients, while FAST score demonstrates moderate performance in identifying fibrotic NASH.

New and emerging treatments for metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is a leading etiology of chronic liver disease worldwide, with increasing incidence and prevalence in the setting of the obesity epidemic. MASH is also a leading indication for liver transplantation, given its associated risk of progression to end-stage liver disease. A key challenge in managing MASH is the lack of approved pharmacotherapy. In its absence, lifestyle interventions with a focus on healthy nutrition and regular physical activity have been the cornerstone of therapy. Real-world efficacy and sustainability of lifestyle interventions are low, however. Pharmacotherapy development for MASH is emerging with promising data from several agents with different mechanisms of action (MOAs) in phase 3 clinical trials. In this review, we highlight ongoing challenges and potential solutions in drug development for MASH and provide an overview of available data from emerging therapies across multiple MOAs.

Performance of ATT and UDFF in the diagnosis of non-alcoholic fatty liver: An animal experiment

Objective

To establish a Bama minipigs model with Non-Alcoholic Fatty Liver (NAFL) induced by a high-fat diet and investigate the application of attenuation coefficient (ATT) and ultrasound-derived fat fraction (UDFF) in the diagnosis of NAFL.

Methods

Six-month-old male Bama minipigs were randomly divided into normal control and high-fat groups (n = 3 pigs per group), and fed with a control diet and high-fat diet for 32 weeks. Weight and body length were measured every four weeks, followed by quantitative ultrasound imaging (ATT and UDFF), blood biochemical markers, and liver biopsies on the same day. Using the Non-Alcoholic Fatty Liver Disease (NAFLD) Activity Score (NAS) as a reference, we analyzed the correlation between ATT, UDFF, and their score results.

Results

Compared with the normal control group, the body weight, body mass index (BMI), and serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in the High-fat group were significantly different at Week 12 (P < 0.05). Spearman correlation analysis showed that the ATT value was significantly correlated with NAS score (r = 0.76, P < 0.001), and the UDFF value was significantly correlated with NAS score (r = 0.80, P < 0.001). The optimal cut-off value of ATT and UDFF were 0.59 dB/cm/MHz and 5.5%, respectively. These values are optimal for diagnosis of NAFL in Bama minipig model.

Conclusion

ATT and UDFF have a high correlation with steatosis, and can be used as a non-invasive method for early screening of hepatic steatosis, which can dynamically monitor the change of disease course.

A natural language processing algorithm accurately classifies steatotic liver disease pathology to estimate the risk of cirrhosis

BACKGROUND

Histopathology remains the gold standard for diagnosing and staging metabolic dysfunction-associated steatotic liver disease (MASLD). The feasibility of studying MASLD progression in electronic medical records based on histological features is limited by the free-text nature of pathology reports. Here we introduce a natural language processing (NLP) algorithm to automatically score MASLD histology features.

METHODS

From the Mass General Brigham health care system electronic medical record, we identified all patients (1987-2021) with steatosis on index liver biopsy after excluding excess alcohol use and other etiologies of liver disease. An NLP algorithm was constructed in Python to detect steatosis, lobular inflammation, ballooning, and fibrosis stage from pathology free-text and manually validated in >1200 pathology reports. Patients were followed from the index biopsy to incident decompensated liver disease accounting for covariates.

RESULTS

The NLP algorithm demonstrated positive and negative predictive values from 93.5% to 100% for all histologic concepts. Among 3134 patients with biopsy-confirmed MASLD followed for 20,604 person-years, rates of the composite endpoint increased monotonically with worsening index fibrosis stage (p for linear trend <0.005). Compared to simple steatosis (incidence rate, 15.06/1000 person-years), the multivariable-adjusted HRs for cirrhosis were 1.04 (0.72-1.5) for metabolic dysfunction-associated steatohepatitis (MASH)/F0, 1.19 (0.92-1.54) for MASH/F1, 1.89 (1.41-2.52) for MASH/F2, and 4.21 (3.26-5.43) for MASH/F3.

CONCLUSIONS

The NLP algorithm accurately scores histological features of MASLD from pathology free-text. This algorithm enabled the construction of a large and high-quality MASLD cohort across a multihospital health care system and disclosed an accelerating risk for cirrhosis based on the index MASLD fibrosis stage.

Impact of age on NIS2+™ and other non-invasive blood tests for the evaluation of liver disease and detection of at-risk MASH

Background & Aims

Robust performance of non-invasive tests (NITs) across ages is critical to assess liver disease among patients with metabolic dysfunction-associated liver disease (MASLD). We evaluated the impact of age on the performance of NIS2+™ vs. other NITs.

Methods

An analysis cohort (N = 1,926) with biopsy-proven MASLD was selected among individuals screened for the phase III RESOLVE-IT clinical trial and divided into ≤45, 46-55, 56-64, and ≥65 years groups. To avoid potential confounding effects, a well-balanced cohort (n = 708; n = 177/age group) was obtained by applying a propensity score-matching algorithm to the analysis cohort. Baseline values of biomarkers and NITs were compared across age groups using one-way ANOVA, and the impact of age and histology were compared through three-way ANOVA. The impact of age on NIT performance for the detection of at-risk metabolic dysfunction-associated steatohepatitis (MASH; MASLD activity score [MAS] ≥4 and fibrosis stage [F] ≥2) was also evaluated.

Results

Age did not affect the distributions of NIS2+™ and APRI (aspartate aminotransferase-to-platelet ratio index), but significantly (p <0.0001) impacted those of NFS (NAFLD fibrosis score), FIB-4 (Fibrosis-4 index), and Enhanced Liver Fibrosis (ELF™) score. NIS2+™ was the only NIT on which fibrosis and MAS exerted a moderate to large effect. While the impact of fibrosis on APRI was moderate, that of MAS was low. The impact of age on FIB-4 and NFS was larger than that of fibrosis. NIS2+™ exhibited the highest AUROC values for detecting at-risk MASH across age groups, with stable performances irrespective of cut-offs.

Conclusions

NIS2+™ was not significantly impacted by age and was sensitive to both fibrosis and MAS grade, demonstrating a robust performance to rule in/out at-risk MASH with fixed cut-offs.

Impact and Implications

While metabolic dysfunction-associated steatotic liver disease (MASLD) can affect individuals of all ages, patient age could represent an important confounding factor when interpreting non-invasive test (NIT) results, highlighting the need for reliable and efficient NITs that are not impacted by age and that could be interpreted with fixed cut-offs, irrespective of patient age. We report the impact of age on different well-established NITs - among those tested, only two panels, NIS2+™ and APRI, were not impacted by age and can be used and interpreted independently of patient age. NIS2+™ was also sensitive to both fibrosis and MAS, further confirming its efficiency for the detection of the composite endpoint of at-risk MASH and its potential as a valuable candidate for large-scale implementation in clinical practice and clinical trials.

MASH clinical trials and drugs pipeline: An impending tsunami

Metabolic dysfunction-associated steatotic liver disease, formerly known as NAFLD, has ascended to prominence as the predominant chronic liver disease in Western countries and now stands as a leading cause of liver transplantations. In the more advanced stage, metabolic dysfunction-associated steatohepatitis (MASH) may lead to fibrosis, a gateway to cirrhosis, liver cancer, and liver failure. Despite extensive research and exploration of various drug mechanisms, the anticipation for the inaugural approved drug to materialize by 2024 is palpable, marking a significant milestone. Numerous pathways have been investigated for MASH treatment, exploring thyroid hormone receptors, glucagon-like peptides 1, peroxisome proliferator-activated receptors, and agents influencing hepatic steatosis synthesis, inflammatory pathways, genetic components, fibrosis mechanisms, and an array of other avenues. Over time, key regulatory directions have crystallized, now manifesting in 2 primary endpoints under investigation: resolution of steatohepatitis without worsening fibrosis and/or improvement of fibrosis stage without worsening of steatohepatitis, especially used in phase 3 clinical trials, while alternative noninvasive endpoints are explored in phase 2 trials. The prospect of proving efficacy in clinical trials opens doors to combination therapies, evaluating the ideal combination of drugs to yield comprehensive benefits, extending beyond the liver to other organs. Certain combination drug trials are already underway. In this review, we discuss the forefront of MASH drug research as of 2023/2024, illuminating mechanisms, outcomes, and future trajectories. Furthermore, we tackle the challenges confronting MASH trials and propose potential strategies for surmounting them.

Machine learning approaches to enhance diagnosis and staging of patients with MASLD using routinely available clinical information

AIMS

Metabolic dysfunction Associated Steatotic Liver Disease (MASLD) outcomes such as MASH (metabolic dysfunction associated steatohepatitis), fibrosis and cirrhosis are ordinarily determined by resource-intensive and invasive biopsies. We aim to show that routine clinical tests offer sufficient information to predict these endpoints.

METHODS

Using the LITMUS Metacohort derived from the European NAFLD Registry, the largest MASLD dataset in Europe, we create three combinations of features which vary in degree of procurement including a 19-variable feature set that are attained through a routine clinical appointment or blood test. This data was used to train predictive models using supervised machine learning (ML) algorithm XGBoost, alongside missing imputation technique MICE and class balancing algorithm SMOTE. Shapley Additive exPlanations (SHAP) were added to determine relative importance for each clinical variable.

RESULTS

Analysing nine biopsy-derived MASLD outcomes of cohort size ranging between 5385 and 6673 subjects, we were able to predict individuals at training set AUCs ranging from 0.719-0.994, including classifying individuals who are At-Risk MASH at an AUC = 0.899. Using two further feature combinations of 26-variables and 35-variables, which included composite scores known to be good indicators for MASLD endpoints and advanced specialist tests, we found predictive performance did not sufficiently improve. We are also able to present local and global explanations for each ML model, offering clinicians interpretability without the expense of worsening predictive performance.

CONCLUSIONS

This study developed a series of ML models of accuracy ranging from 71.9-99.4% using only easily extractable and readily available information in predicting MASLD outcomes which are usually determined through highly invasive means.

A MUFA/carotenoid-rich oil ameliorated insulin resistance by improving inflammation and oxidative stress in obese rats

Obesity is associated with low-grade inflammation and oxidative stress, leading to insulin resistance and type II diabetes. Caryocar brasiliense pulp oil (pequi oil - PO) is rich in oleic acid and carotenoids and positively implicated in regulating inflammation and oxidative stress. This study investigated PO's antioxidant and anti-inflammatory effects in a diet-induced obesity model. Male Wistar rats were allocated into three experimental groups: Control (CD), Western Diet (WD), and Western Diet, with 27% of lard switched by PO (WDP). Metabolic, inflammatory, and oxidative stress biomarkers were evaluated after 12 weeks of diet protocols in liver and adipose tissue. WDP rats gained less body mass and epididymal fat, had less hepatic fat infiltration, and were more glucose-tolerant and insulin-sensitive than WD (p < 0.05). In the liver, the WDP group had the highest non-enzymatic antioxidant capacity, SOD and GPx activities, CAT, SOD II, and HSP72 expression compared to WD (p < 0.05). Adipose tissue IL-6 and TNF were reduced, and IL-10 was increased in WDP compared to WD (p < 0.05). Our data suggest that the partial replacement of lard by PO in a Western diet prevented visceral fat accumulation and contributed to reducing inflammation in adipose tissue and liver oxidative stress, improving obesity-related insulin resistance.

Object detection: A novel AI technology for the diagnosis of hepatocyte ballooning

Metabolic dysfunction-associated fatty liver disease (MAFLD) has reached epidemic proportions worldwide and is the most frequent cause of chronic liver disease in developed countries. Within the spectrum of liver disease in MAFLD, steatohepatitis is a progressive form of liver disease and hepatocyte ballooning (HB) is a cardinal pathological feature of steatohepatitis. The accurate and reproducible diagnosis of HB is therefore critical for the early detection and treatment of steatohepatitis. Currently, a diagnosis of HB relies on pathological examination by expert pathologists, which may be a time-consuming and subjective process. Hence, there has been interest in developing automated methods for diagnosing HB. This narrative review briefly discusses the development of artificial intelligence (AI) technology for diagnosing fatty liver disease pathology over the last 30 years and provides an overview of the current research status of AI algorithms for the identification of HB, including published articles on traditional machine learning algorithms and deep learning algorithms. This narrative review also provides a summary of object detection algorithms, including the principles, historical developments, and applications in the medical image analysis. The potential benefits of object detection algorithms for HB diagnosis (specifically those combined with a transformer architecture) are discussed, along with the future directions of object detection algorithms in HB diagnosis and the potential applications of generative AI on transformer architecture in this field. In conclusion, object detection algorithms have huge potential for the identification of HB and could make the diagnosis of MAFLD more accurate and efficient in the near future.

Artificial intelligence-assisted digital pathology for non-alcoholic steatohepatitis: current status and future directions

The worldwide prevalence of non-alcoholic steatohepatitis (NASH) is increasing, causing a significant medical burden, but no approved therapeutics are currently available. NASH drug development requires histological analysis of liver biopsies by expert pathologists for trial enrolment and efficacy assessment, which can be hindered by multiple issues including sample heterogeneity, inter-reader and intra-reader variability, and ordinal scoring systems. Consequently, there is a high unmet need for accurate, reproducible, quantitative, and automated methods to assist pathologists with histological analysis to improve the precision around treatment and efficacy assessment. Digital pathology (DP) workflows in combination with artificial intelligence (AI) have been established in other areas of medicine and are being actively investigated in NASH to assist pathologists in the evaluation and scoring of NASH histology. DP/AI models can be used to automatically detect, localise, quantify, and score histological parameters and have the potential to reduce the impact of scoring variability in NASH clinical trials. This narrative review provides an overview of DP/AI tools in development for NASH, highlights key regulatory considerations, and discusses how these advances may impact the future of NASH clinical management and drug development. This should be a high priority in the NASH field, particularly to improve the development of safe and effective therapeutics.

Long-term major adverse liver outcomes in 1,260 patients with non-cirrhotic NAFLD

Background & Aims

Long-term studies of the prognosis of NAFLD are scarce. Here, we investigated the risk of major adverse liver outcomes (MALO) in a large cohort of patients with NAFLD.

Methods

We conducted a cohort study with data from Swedish university hospitals. Patients (n = 1,260) with NAFLD without cirrhosis were diagnosed through biopsy or radiology, and had fibrosis estimated through vibration-controlled transient elastography, biopsy, or FIB-4 score between 1974 and 2020 and followed up through 2020. Each patient was matched on age, sex, and municipality with up to 10 reference individuals from the general population (n = 12,529). MALO were ascertained from Swedish national registers. The rate of events was estimated by Cox regression.

Results

MALO occurred in 111 (8.8%, incidence rate = 5.9/1,000 person-years) patients with NAFLD and 197 (1.6%, incidence rate = 1.0/1,000 person-years) reference individuals during a median follow up of 13 years. The rate of MALO was higher in patients with NAFLD (hazard ratio = 6.6; 95% CI = 5.2-8.5). The risk of MALO was highly associated with the stage of fibrosis at diagnosis. In the biopsy subcohort (72% of total sample), there was no difference in risk between patients with and without non-alcoholic steatohepatitis. The 20-year cumulative incidences of MALO were 2% for the reference population, 3% for patients with F0, and 35% for F3. Prognostic information from biopsy was comparable to FIB-4 (C-indices around 0.73 vs. 0.72 at 10 years).

Conclusions

This study provides updated information on the natural history of NAFLD, showing a high rate of progression to cirrhosis in F3 and a similar prognostic capacity of non-invasive tests to liver biopsy.

Impact and implications

Several implications for clinical care and future research may be noted based on these results. First, the risk estimates for cirrhosis development are important when communicating risk to patients and deciding on clinical monitoring and treatment. Estimates can also be used in updated health-economic evaluations, and for regulatory agencies. Second, our results again highlight the low predictive information obtained from ascertaining NASHstatus by histology and call for more objective means by which to define NASH. Such methods may include artificial intelligence-supported digital pathology. We highlight that NASH is most likely the causal factor for fibrosis progression in NAFLD, but the subjective definition makes the prognostic value of a histological NASH diagnosis of limited value. Third, the finding that prognostic information from biopsy and the very simple Fibrosis-4 score were comparable is important as it may lead to fewer biopsies and further move the field towards non-invasive means by which to define fibrosis and, importantly, use non-invasive tests as outcomes in clinical trials. However, all modalities had modest discriminatory capacity and new risk stratification systems are needed in NAFLD. Repeated measures of non-invasive scores may be a potential solution.

Liver fibrosis in NAFLD/NASH: from pathophysiology towards diagnostic and therapeutic strategies

Liver fibrosis, as an excess deposition of extracellular matrix (ECM) components, results from chronic liver injury as well as persistent activation of inflammatory response and of fibrogenesis. Liver fibrosis is a major determinant for chronic liver disease (CLD) progression and in the last two decades our understanding on the major molecular and cellular mechanisms underlying the fibrogenic progression of CLD has dramatically improved, boosting pre-clinical studies and clinical trials designed to find novel therapeutic approaches. From these studies several critical concepts have emerged, starting to reveal the complexity of the pro-fibrotic microenvironment which involves very complex, dynamic and interrelated interactions between different hepatic and extrahepatic cell populations. This review will offer first a recapitulation of established and novel pathophysiological basic principles and concepts by intentionally focus the attention on NAFLD/NASH, a metabolic-related form of CLD with a high impact on the general population and emerging as a leading cause of CLD worldwide. NAFLD/NASH-related pro-inflammatory and profibrogenic mechanisms will be analysed as well as novel information on cells, mediators and signalling pathways which have taken advantage from novel methodological approaches and techniques (single cell genomics, imaging mass cytometry, novel in vitro two- and three-dimensional models, etc.). We will next offer an overview on recent advancement in diagnostic and prognostic tools, including serum biomarkers and polygenic scores, to support the analysis of liver biopsies. Finally, this review will provide an analysis of current and emerging therapies for the treatment of NAFLD/NASH patients.

Hepatocellular Ballooning is Due to Highly Pronounced Glycogenosis Potentially Associated with Steatosis and Metabolic Reprogramming

Background and Aims

Hepatocellular ballooning is a common finding in chronic liver disease, mainly characterized by rarefied cytoplasm that often contains Mallory-Denk bodies (MDB). Ballooning has mostly been attributed to degeneration but its striking resemblance to glycogenotic/steatotic changes characterizing preneoplastic hepatocellular lesions in animal models and chronic human liver diseases prompts the question whether ballooned hepatocytes (BH) are damaged cells on the path to death or rather viable cells, possibly involved in neoplastic development.

Methods

Using specimens from 96 cirrhotic human livers, BH characteristics were assessed for their glycogen/lipid stores, enzyme activities, and proto-oncogenic signaling cascades by enzyme- and immunohistochemical approaches with serial paraffin and cryostat sections.

Results

BH were present in 43.8% of cirrhotic livers. Particularly pronounced excess glycogen storage of (glycogenosis) and/or lipids (steatosis) were characteristic, ground glass features and MDB were often observed. Decreased glucose-6-phosphatase, increased glucose-6-phosphate dehydrogenase activity and altered immunoreactivity of enzymes involved in glycolysis, lipid metabolism, and cholesterol biosynthesis were discovered. Furthermore, components of the insulin signaling cascade were upregulated along with insulin dependent glucose transporter glucose transporter 4 and the v-akt murine thymoma viral oncogene homolog/mammalian target of rapamycin signaling pathway associated with de novo lipogenesis.

Conclusions

BH are hallmarked by particularly pronounced glycogenosis with facultative steatosis, many of their features being reminiscent of metabolic aberrations documented in preneoplastic hepatocellular lesions in experimental animals and chronic human liver diseases. Hence, BH are not damaged entities facing death but rather viable cells featuring metabolic reprogramming, indicative of a preneoplastic nature.

Translating the potential of the urine steroid metabolome to stage NAFLD (TrUSt-NAFLD): study protocol for a multicentre, prospective validation study

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) affects approximately one in four individuals and its prevalence continues to rise. The advanced stages of NAFLD with significant liver fibrosis are associated with adverse morbidity and mortality outcomes. Currently, liver biopsy remains the 'gold-standard' approach to stage NAFLD severity. Although generally well tolerated, liver biopsies are associated with significant complications, are resource intensive, costly, and sample only a very small area of the liver as well as requiring day case admission to a secondary care setting. As a result, there is a significant unmet need to develop non-invasive biomarkers that can accurately stage NAFLD and limit the need for liver biopsy. The aim of this study is to validate the use of the urine steroid metabolome as a strategy to stage NAFLD severity and to compare its performance against other non-invasive NAFLD biomarkers.

METHODS AND ANALYSIS

The TrUSt-NAFLD study is a multicentre prospective test validation study aiming to recruit 310 patients with biopsy-proven and staged NAFLD across eight centres within the UK. 150 appropriately matched control patients without liver disease will be recruited through the Oxford Biobank. Blood and urine samples, alongside clinical data, will be collected from all participants. Urine samples will be analysed by liquid chromatography-tandem mass spectroscopy to quantify a panel of predefined steroid metabolites. A machine learning-based classifier, for example, Generalized Matrix Relevance Learning Vector Quantization that was trained on retrospective samples, will be applied to the prospective steroid metabolite data to determine its ability to identify those patients with advanced, as opposed to mild-moderate, liver fibrosis as a consequence of NAFLD.

ETHICS AND DISSEMINATION

Research ethical approval was granted by West Midlands, Black Country Research Ethics Committee (REC reference: 21/WM/0177). A substantial amendment (TrUSt-NAFLD-SA1) was approved on 26 November 2021.

TRIAL REGISTRATION NUMBER

ISRCTN19370855.

Design of the phase 3 MAESTRO clinical program to evaluate resmetirom for the treatment of nonalcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) associated with steatosis, hepatocellular injury, inflammation and fibrosis. In a Phase 2 trial in adults with NASH (NCT02912260), resmetirom, an orally administered, liver-targeted thyroid hormone receptor-β selective agonist, significantly reduced hepatic fat (via imaging) and resolved NASH without worsening fibrosis (via liver biopsy) in a significant number of patients compared with placebo.

AIMS

To present the design of the Phase 3 MAESTRO clinical programme evaluating resmetirom for treatment of NASH (MAESTRO-NAFLD-1 [NCT04197479], MAESTRO-NAFLD-OLE [NCT04951219], MAESTRO-NASH [NCT03900429], MAESTRO-NASH-OUTCOMES [NCT05500222]).

METHODS

MAESTRO-NASH is a pivotal serial biopsy trial in up to 2000 adults with biopsy-confirmed at-risk NASH. Patients are randomised to a once-daily oral placebo, 80 mg resmetirom, or 100 mg resmetirom. Liver biopsies are conducted at screening, week 52 and month 54. MAESTRO-NAFLD-1 is a 52-week safety trial in ~1400 adults with NAFLD/presumed NASH (based on non-invasive testing); ~700 patients from MAESTRO-NAFLD-1 are enrolled in MAESTRO-NAFLD-OLE, a 52-week active treatment extension to further evaluate safety. MAESTRO-NASH-OUTCOMES is enrolling 700 adults with well-compensated NASH cirrhosis to evaluate the potential for resmetirom to slow progression to hepatic decompensation events. Non-invasive tests (biomarkers, imaging) are assessed longitudinally throughout, in addition to validated patient-reported outcomes.

CONCLUSION

The MAESTRO clinical programme was designed in conjunction with regulatory authorities to support approval of resmetirom for treatment of NASH. The surrogate endpoints, based on week 52 liver biopsy, serum biomarkers and imaging, are confirmed by long-term clinical liver-related outcomes in MAESTRO-NASH (month 54) and MAESTRO-NASH-OUTCOMES (time to event).

Visco-Elastic Parameters at Three-Dimensional MR Elastography for Diagnosing Non-Alcoholic Steatohepatitis and Substantial Fibrosis in Mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasing worldwide and is a growing cause of liver cirrhosis and cancer. The performance of the magnetic resonance elastography (MRE) visco-elastic parameters in diagnosing progressive forms of NAFLD, including nonalcoholic steatohepatitis (NASH) and substantial fibrosis (F ≥ 2), needs to be clarified.

PURPOSE

To assess the value of three-dimensional MRE visco-elastic parameters as markers of NASH and substantial fibrosis in mice with NAFLD.

STUDY TYPE

Prospective.

ANIMAL MODEL

Two mouse models of NAFLD were induced by feeding with high fat diet or high fat, choline-deficient, amino acid-defined diet.

FIELD STRENGTH/SEQUENCE

7T/multi-slice multi-echo spin-echo MRE at 400 Hz with motion encoding in the three spatial directions.

ASSESSMENT

Hepatic storage and loss moduli were calculated. Histological analysis was based on the NASH Clinical Research Network criteria.

STATISTICAL TESTS

Mann-Whitney, Kruskal-Wallis tests, Spearman rank correlations and multiple regressions were used. Diagnostic performance was assessed with areas under the receiver operating characteristic curves (AUCs). P value <0.05 was considered significant.

RESULTS

Among the 59 mice with NAFLD, 21 had NASH and 20 had substantial fibrosis (including 8 mice without and 12 mice with NASH). The storage and loss moduli had similar moderate accuracy for diagnosing NASH with AUCs of 0.67 and 0.66, respectively. For diagnosing substantial fibrosis, the AUC of the storage modulus was 0.73 and the AUC of the loss modulus was 0.81, indicating good diagnostic performance. Using Spearman correlations, histological fibrosis, inflammation and steatosis, but not ballooning, were significantly correlated with the visco-elastic parameters. Using multiple regression, fibrosis was the only histological feature independently associated with the visco-elastic parameters.

CONCLUSION

MRE in mice with NAFLD suggests that the storage and loss moduli have good diagnostic performance for detecting progressive NAFLD defined as substantial fibrosis rather than NASH.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY STAGE: 2.

Digital pathology for nonalcoholic steatohepatitis assessment

Histological assessment of nonalcoholic fatty liver disease (NAFLD) has anchored knowledge development about the phenotypes of the condition, their natural history and their clinical course. This fact has led to the use of histological assessment as a reference standard for the evaluation of efficacy of drug interventions for nonalcoholic steatohepatitis (NASH) - the more histologically active form of NAFLD. However, certain limitations of conventional histological assessment systems pose challenges in drug development. These limitations have spurred intense scientific and commercial development of machine learning and digital approaches towards the assessment of liver histology in patients with NAFLD. This research field remains an area in rapid evolution. In this Perspective article, we summarize the current conventional assessment of NASH and its limitations, the use of specific digital approaches for histological assessment, and their application to the study of NASH and its response to therapy. Although this is not a comprehensive review, the leading tools currently used to assess therapeutic efficacy in drug development are specifically discussed. The potential translation of these approaches to support routine clinical assessment of NAFLD and an agenda for future research are also discussed.

Cenicriviroc Lacked Efficacy to Treat Liver Fibrosis in Nonalcoholic Steatohepatitis: AURORA Phase III Randomized Study

BACKGROUND AND AIMS

Cenicriviroc (CVC) is a novel, orally administered, chemokine receptor type 2 and 5 antagonist that showed antifibrotic potential in preclinical and phase IIb studies of nonalcoholic steatohepatitis (NASH). Herein, we report efficacy and safety results from the phase III study.

METHODS

The AURORA (A Study for the Efficacy and Safety of CVC for the Treatment of Liver Fibrosis in Adults With NASH) study was a phase III, randomized, double-blind, placebo-controlled, 2-part study of patients with NASH and stage 2/3 liver fibrosis. Adults, 18-75 years of age, were randomized to CVC 150 mg or placebo once daily for 12 months (part 1) or 60 months (part 2). Liver biopsies were performed at screening, month 12, and early study discontinuation or termination. The primary efficacy endpoint was the proportion of patients with fibrosis improvement ≥1 stage without worsening of steatohepatitis at month 12 relative to screening. Adverse events were assessed throughout the study.

RESULTS

A total of 1778 patients were randomized and discontinued (part 1: n = 1293; part 2: n = 485). In part 1, at month 12, a similar proportion of patients receiving CVC or placebo achieved the primary endpoint (22.3% vs 25.5%; odds ratio, 0.84; 95% confidence interval, 0.63-1.10; P = .21) and complete resolution of steatohepatitis without worsening of fibrosis (23.0% vs 27.2%; P = .21). The safety profile was generally comparable across treatment groups.

CONCLUSIONS

This study did not demonstrate the efficacy of CVC for treating liver fibrosis assessed by histology in adults with NASH; however, CVC was safe and well tolerated in patients with NASH and liver fibrosis. (ClinicalTrials.gov, Number: NCT03028740).

Prognostic utility of Fibrosis-4 Index for risk of subsequent liver and cardiovascular events, and all-cause mortality in individuals with obesity and/or type 2 diabetes: a longitudinal cohort study

Background

The Fibrosis-4 Index (FIB-4) is used as a non-invasive tool for the presence of advanced liver fibrosis in metabolic dysfunction-associated steatotic liver disease and type 2 diabetes. However, evidence for an association between FIB-4 and risk of mortality and/or liver-related clinical outcomes is limited. The aim of this study was to investigate the association between FIB-4 and subsequent liver events, cardiovascular events, and all-cause mortality in individuals with obesity and/or type 2 diabetes examined in routine general practice.

Methods

This was a longitudinal cohort study in which eligible adults had obesity and/or type 2 diabetes and ≥1 FIB-4 score calculable from UK Clinical Practice Research Datalink GOLD after 1 January 2001. No alcohol-related disorders and/or chronic liver diseases (except non-alcoholic fatty liver disease) and/or no prescriptions of drugs inducing liver disease were permitted. Individuals were followed until time of first event, 10 years, or 1 January 2020. Analyses were conducted using Aalen-Johansen cumulative incidence functions and Cox proportional hazards models.

Findings

Among 44,481 included individuals (mean age 58·8 years; 54% female), there were 979 liver, 6002 cardiovascular, and 8971 mortality events during the 10 years of follow-up. At 10 years, the cumulative incidence of liver events in the high (>2·67), indeterminate (1·30-2·67), and low (<1·30) baseline FIB-4 risk groups were 15%, 3%, and 1%, respectively. Age- and sex-adjusted hazard ratios (HRs) for liver events were elevated in high (16·46; 95% confidence interval [CI] 13·65-19·85) and indeterminate (2·45; 95% CI 2·07-2·90) versus low FIB-4 risk groups. Similar results were found for cardiovascular events and all-cause mortality. Among 20,433 individuals with ≥2 FIB-4 measurements, increase/decrease in FIB-4 12 months after baseline was directly associated with risk of liver events: compared with individuals with low baseline FIB-4 and no change in FIB-4 (reference), the adjusted HR (95% CI) for those with high baseline FIB-4 was 24·27 (16·98-34·68) with a one-unit FIB-4 increase, and 10·90 (7·90-15·05) with a one-unit decrease.

Interpretation

In addition to its value as a diagnostic tool, FIB-4 has clinical utility as a prognostic biomarker. Sequential measurement provides a pragmatic, tractable monitoring biomarker that refines risk assessment for liver events, cardiovascular events, and mortality.

Funding

Novo Nordisk A/S.

Utility of pathologist panels for achieving consensus in NASH histologic scoring in clinical trials: Data from a phase 3 study

BACKGROUND

Liver histopathologic assessment is the accepted surrogate endpoint in NASH trials; however, the scoring of NASH Clinical Research Network (CRN) histologic parameters is limited by intraobserver and interobserver variability. We designed a consensus panel approach to minimize variability when using this scoring system. We assessed agreement between readers, estimated linear weighted kappas between 2 panels, compared them with published pairwise kappa estimates, and addressed how agreement or disagreement might impact the precision and validity of the surrogate efficacy endpoint in NASH trials.

METHODS

Two panels, each comprising 3 liver fellowship-trained pathologists who underwent NASH histology training, independently evaluated scanned whole slide images, scoring fibrosis, inflammation, hepatocyte ballooning, and steatosis from baseline and month 18 biopsies for 100 patients from the precirrhotic NASH study REGENERATE. The consensus score for each parameter was defined as agreement by ≥2 pathologists. If consensus was not reached, all 3 pathologists read the slide jointly to achieve a consensus score.

RESULTS

Between the 2 panels, the consensus was 97%-99% for steatosis, 91%-93% for fibrosis, 88%-92% for hepatocyte ballooning, and 84%-91% for inflammation. Linear weighted kappa scores between panels were similar to published NASH CRN values.

CONCLUSIONS

A panel of 3 trained pathologists independently scoring 4 NASH CRN histology parameters produced high consensus rates. Interpanel kappa values were comparable to NASH CRN metrics, supporting the accuracy and reproducibility of this method. The high concordance for fibrosis scoring was reassuring, as fibrosis is predictive of liver-specific outcomes and all-cause mortality.

Survey of liver pathologists to assess attitudes towards digital pathology and artificial intelligence

AIMS

A survey of members of the UK Liver Pathology Group (UKLPG) was conducted, comprising consultant histopathologists from across the UK who report liver specimens and participate in the UK National Liver Pathology External Quality Assurance scheme. The aim of this study was to understand attitudes and priorities of liver pathologists towards digital pathology and artificial intelligence (AI).

METHODS

The survey was distributed to all full consultant members of the UKLPG via email. This comprised 50 questions, with 48 multiple choice questions and 2 free-text questions at the end, covering a range of topics and concepts pertaining to the use of digital pathology and AI in liver disease.

RESULTS

Forty-two consultant histopathologists completed the survey, representing 36% of fully registered members of the UKLPG (42/116). Questions examining digital pathology showed respondents agreed with the utility of digital pathology for primary diagnosis 83% (34/41), second opinions 90% (37/41), research 85% (35/41) and training and education 95% (39/41). Fatty liver diseases were an area of demand for AI tools with 80% in agreement (33/41), followed by neoplastic liver diseases with 59% in agreement (24/41). Participants were concerned about AI development without pathologist involvement 73% (30/41), however, 63% (26/41) disagreed when asked whether AI would replace pathologists.

CONCLUSIONS

This study outlines current interest, priorities for research and concerns around digital pathology and AI for liver pathologists. The majority of UK liver pathologists are in favour of the application of digital pathology and AI in clinical practice, research and education.

FibroScan-aspartate aminotransferase (FAST) score for monitoring histological improvement in non-alcoholic steatohepatitis activity during semaglutide treatment: post-hoc analysis of a randomised, double-blind, placebo-controlled, phase 2b trial

Background

Currently, assessment of candidate pharmacotherapies in patients with non-alcoholic steatohepatitis (NASH) involves invasive liver biopsy. Non-invasive scores, such as the FibroScan-aspartate aminotransferase (FAST) score, are used to identify candidates for therapy, but their ability to assess disease progression or treatment effect is unknown. We aimed to assess the association between FAST score and histological endpoints.

Methods

We conducted a post-hoc analysis using data from a prior randomised, double-blind, placebo-controlled, phase 2b trial at 143 sites across 16 countries. Patients (aged 18-75 years) with biopsy-confirmed NASH, fibrosis stage 1-3, and a Non-alcoholic fatty liver disease Activity Score (NAS) ≥4 were enrolled between January 2017 and September 2018, and randomly assigned to receive once-daily subcutaneous semaglutide 0.1, 0.2, or 0.4 mg or placebo for 72 weeks. A subgroup analysis of patients with FAST score and histological data in the pooled semaglutide treatment and placebo arms at baseline and week 72 was performed. The original trial is registered at ClinicalTrials.gov, NCT02970942.

Findings

A total of 122 patients were included in this post-hoc analysis (93 received semaglutide and 29 received placebo). FAST score reduction was associated with achieving the primary endpoint of NASH resolution without worsening of fibrosis in the pooled semaglutide group (area under the receiver operating curve 0.69; 95% confidence interval [CI] 0.58, 0.81). Mean FAST score reduction from baseline to week 72 was greatest in patients who met the primary endpoint vs those who did not in both the semaglutide (-0.40 [95% CI -0.84, 0.04] vs -0.22 [95% CI -0.74, 0.30] points; p = 0.002) and placebo groups (-0.25 [95% CI -0.72, 0.23] vs 0.00 [95% CI -0.50, 0.50] points; p = 0.047). Similarly, mean reductions in FAST score at week 72 were greater in those with NAS improvement vs those without in the semaglutide and placebo groups (≥1 point, -0.36 [95% CI -0.82, 0.11] vs -0.08 [95% CI -0.53, 0.38] points [p < 0.001] and -0.25 [95% CI -0.64, 0.14] vs -0.06 [95% CI -0.40, 0.53] points [p = 0.001]; ≥2 points, -0.40 [95% CI -0.86, 0.06] vs -0.14 [95% CI -0.56, 0.28] points [p < 0.001] and -0.29 [95% CI -0.67, 0.09] vs -0.05 [95% CI -0.40, 0.50] points; [p < 0.001]). A FAST score reduction of more than 0.22 points after semaglutide treatment was associated with meeting the primary endpoint (sensitivity 78%; specificity 60%; positive likelihood ratio 1.26; negative likelihood ratio 0.25; odds ratio 4.93).

Interpretation

The potential of the FAST score as a non-invasive monitoring tool to identify histological changes following treatment requires further evaluation and validation.

Funding

Novo Nordisk A/S.

Results from a new efficacy and safety analysis of the REGENERATE trial of obeticholic acid for treatment of pre-cirrhotic fibrosis due to non-alcoholic steatohepatitis

BACKGROUND & AIMS

Obeticholic acid (OCA) is a first-in-class farnesoid X receptor agonist and antifibrotic agent in development for the treatment of pre-cirrhotic liver fibrosis due to non-alcoholic steatohepatitis (NASH). We aimed to validate the original 18-month liver biopsy analysis from the phase III REGENERATE trial of OCA for the treatment of NASH with a consensus panel analysis, provide additional histology data in a larger population, and evaluate safety from >8,000 total patient-years' exposure with nearly 1,000 participants receiving study drug for >4 years.

METHODS

Digitized whole-slide images were evaluated independently by panels of three pathologists using the NASH Clinical Research Network scoring system. Primary endpoints were (1) ≥1 stage improvement in fibrosis with no worsening of NASH or (2) NASH resolution with no worsening of fibrosis. Safety was assessed by laboratory values and adverse events.

RESULTS

Prespecified efficacy analyses included 931 participants. The proportion of participants achieving a ≥1 stage improvement in fibrosis with no worsening of NASH was 22.4% for OCA 25 mg vs. 9.6% for placebo (p <0.0001). More participants receiving OCA 25 mg vs. placebo achieved NASH resolution with no worsening of fibrosis (6.5% vs. 3.5%, respectively; p = 0.093). Histology data in a larger population of 1,607 participants supported these results. Safety data included 2,477 participants. The incidence of treatment-emergent adverse events (TEAEs), serious TEAEs, and deaths was not substantively different across treatment groups. Pruritus was the most common TEAE. Rates of adjudicated hepatic, renal, and cardiovascular events were low and similar across treatment groups.

CONCLUSIONS

These results confirm the antifibrotic effect of OCA 25 mg. OCA was generally well tolerated over long-term dosing. These data support a positive benefit:risk profile in patients with pre-cirrhotic liver fibrosis due to NASH.

IMPACT AND IMPLICATIONS

Patients with non-alcoholic steatohepatitis (NASH) often have liver scarring (fibrosis), which causes an increased risk of liver-related illness and death. Preventing progression of fibrosis to cirrhosis or reversing fibrosis are the main goals of drug development for NASH. In this clinical trial of obeticholic acid (OCA) in patients with NASH (REGENERATE), we reaffirmed our previous results demonstrating that OCA was superior to placebo in improving fibrosis using a more rigorous consensus panel analysis of liver biopsies taken at month 18. We also showed that OCA treatment resulted in dose-dependent reductions of serum liver biochemistries and liver stiffness measurements compared with placebo, even in participants in whom histologic fibrosis did not change at 18 months, providing evidence that the benefit of OCA extends beyond what is captured by the ordinal NASH CRN scoring system. OCA was well tolerated with a favorable safety profile supporting a positive benefit: risk profile in patients with pre-cirrhotic liver fibrosis due to NASH.

Clinical trial: Effects of pegozafermin on the liver and on metabolic comorbidities in subjects with biopsy-confirmed nonalcoholic steatohepatitis

BACKGROUND

An approved therapy for nonalcoholic steatohepatitis (NASH) and fibrosis remains a major unmet medical need.

AIM

To investigate the histological and metabolic benefits of pegozafermin, a glycoPEGylated FGF21 analogue, in subjects with biopsy-confirmed NASH.

METHODS

This proof-of-concept, open-label, single-cohort study, part 2 of a phase 1b/2a clinical trial, was conducted at 16 centres in the United States. Adults (age 21-75 years) with NASH (stage 2 or 3 fibrosis, NAS≥4) and magnetic resonance imaging proton density fat fraction (MRI-PDFF) ≥8% received subcutaneous pegozafermin 27 mg once weekly for 20 weeks. Primary outcomes were improvements in liver histology, and safety and tolerability.

RESULTS

Of 20 enrolled subjects, 19 completed the study. Twelve subjects (63%) met the primary endpoint of ≥2-point improvement in NAFLD activity score with ≥1-point improvement in ballooning or lobular inflammation and no worsening of fibrosis. Improvement of fibrosis without worsening of NASH was observed in 26% of subjects, and NASH resolution without worsening of fibrosis in 32%. Least-squares mean relative change from baseline in MRI-PDFF was -64.7% (95% CI: -71.7, -57.7; p < 0.0001). Significant improvements from baseline were also seen in serum aminotransferases, noninvasive fibrosis tests, serum lipids, glycaemic control and body weight. Adverse events (AEs) were reported in 18 subjects (90%). The most frequently reported AEs were mild/moderate nausea and diarrhoea. There were no serious AEs, discontinuations due to AEs, or deaths.

CONCLUSIONS

Pegozafermin treatment for 20 weeks had beneficial effects on hepatic and metabolic parameters and was well tolerated in subjects with NASH.

CLINICALTRIALS

gov: NCT04048135.

Liver Investigation: Testing Marker Utility in Steatohepatitis (LITMUS): Assessment & validation of imaging modality performance across the NAFLD spectrum in a prospectively recruited cohort study (the LITMUS imaging study): Study protocol

Non-alcoholic fatty liver disease (NAFLD) is the liver manifestation of the metabolic syndrome with global prevalence reaching epidemic levels. Despite the high disease burden in the population only a small proportion of those with NAFLD will develop progressive liver disease, for which there is currently no approved pharmacotherapy. Identifying those who are at risk of progressive NAFLD currently requires a liver biopsy which is problematic. Firstly, liver biopsy is invasive and therefore not appropriate for use in a condition like NAFLD that affects a large proportion of the population. Secondly, biopsy is limited by sampling and observer dependent variability which can lead to misclassification of disease severity. Non-invasive biomarkers are therefore needed to replace liver biopsy in the assessment of NAFLD. Our study addresses this unmet need. The LITMUS Imaging Study is a prospectively recruited multi-centre cohort study evaluating magnetic resonance imaging and elastography, and ultrasound elastography against liver histology as the reference standard. Imaging biomarkers and biopsy are acquired within a 100-day window. The study employs standardised processes for imaging data collection and analysis as well as a real time central monitoring and quality control process for all the data submitted for analysis. It is anticipated that the high-quality data generated from this study will underpin changes in clinical practice for the benefit of people with NAFLD. Study Registration: clinicaltrials.gov: NCT05479721.

Serum levels of fibrogenesis biomarkers reveal distinct endotypes predictive of response to weight loss in advanced nonalcoholic fatty liver disease

BACKGROUND

NAFLD is associated with activation of fibroblasts and hepatic fibrosis. Substantial patient heterogeneity exists, so it remains challenging to risk-stratify patients. We hypothesized that the amount of fibroblast activity, as assessed by circulating biomarkers of collagen formation, can define a "high-risk, high-fibrogenesis" patient endotype that exhibits greater fibroblast activity and potentially more progressive disease, and this endotype may be more amendable to dietary intervention.

METHODS

Patients with clinically confirmed advanced NAFLD were prescribed a very low-calorie diet (VLCD) intervention (∼800 kcal/d) to induce weight loss, achieved using total diet replacement. Serum markers of type III (PRO-C3) and IV collagen (PRO-C4) fibrogenesis were assessed at baseline every second week until the end of the VLCD, and 4 weeks post-VLCD and at 9 months follow-up.

RESULTS

Twenty-six subjects had a mean weight loss of 9.7% with VLCD. This was associated with significant improvements in liver biochemistry. When stratified by baseline PRO-C3 and PRO-C4 into distinct fibrosis endotypes, these predicted substantial differences in collagen fibrogenesis marker dynamics in response to VLCD. Patients in the high activity group (PRO-C3 >11.4 ng/mL and/or PRO-C4 >236.5 ng/mL) exhibited a marked reduction of collagen fibrogenesis, ranging from a 40%-55% decrease in PRO-C3 and PRO-C4, while fibrogenesis remained unchanged in the low activity group. The biochemical response to weight loss was substantially greater in patients a priori exhibiting a high fibroblast activity endotype in contrast to patients with low activity.

CONCLUSIONS

Thus, the likelihood of treatment response may be predicted at baseline by quantification of fibrogenesis biomarkers.

The future of incretins in the treatment of obesity and non-alcoholic fatty liver disease

In the last few decades, glucagon-like peptide-1 receptor (GLP-1R) agonists have changed current guidelines and improved outcomes for individuals with type 2 diabetes. However, the dual glucose-dependent insulinotropic polypeptide receptor (GIPR)/GLP-1R agonist, tirzepatide, has demonstrated superior efficacy regarding improvements in HbA1c and body weight in people with type 2 diabetes. This has led to increasing scientific interest in incretin hormones and incretin interactions, and several compounds based on dual- and multi-agonists are now being investigated for the treatment of metabolic diseases. Herein, we highlight the key scientific advances in utilising incretins for the treatment of obesity and, potentially, non-alcoholic fatty liver disease (NAFLD). The development of multi-agonists with multi-organ targets may alter the natural history of these diseases.

Tropifexor plus cenicriviroc combination versus monotherapy in nonalcoholic steatohepatitis: Results from the phase 2b TANDEM study

BACKGROUND AND AIMS

With distinct mechanisms of action, the combination of tropifexor (TXR) and cenicriviroc (CVC) may provide an effective treatment for NASH. This randomized, multicenter, double-blind, phase 2b study assessed the safety and efficacy of TXR and CVC combination, compared with respective monotherapies.

APPROACH AND RESULTS

Patients (N = 193) were randomized 1:1:1:1 to once-daily TXR 140 μg (TXR 140 ), CVC 150 mg (CVC), TXR 140 μg + CVC 150 mg (TXR 140 + CVC), or TXR 90 μg + CVC 150 mg (TXR 90 + CVC) for 48 weeks. The primary and secondary end points were safety and histological improvement, respectively. Rates of adverse events (AEs) were similar across treatment groups. Pruritus was the most frequently experienced AE, with highest incidence in the TXR 140 group (40.0%). In TXR and combination groups, alanine aminotransferase (ALT) decreased from baseline to 48 weeks (geometric mean change: -21%, TXR 140 ; -16%, TXR 140 + CVC; -13%, TXR 90 + CVC; and +17%, CVC). Reductions in body weight observed at week 24 (mean changes from baseline: TXR 140 , -2.5 kg; TXR 140 + CVC, -1.7 kg; TXR 90 + CVC, -1.0 kg; and CVC, -0.1 kg) were sustained to week 48. At least 1-point improvement in fibrosis stage/steatohepatitis resolution without worsening of fibrosis was observed in 32.3%/25.8%, 31.6%/15.8%, 29.7%/13.5%, and 32.5%/22.5% of patients in the TXR 140 , CVC, TXR 140 + CVC, and TXR 90 + CVC groups, respectively.

CONCLUSIONS

The safety profile of TXR + CVC combination was similar to respective monotherapies, with no new signals. TXR monotherapy showed sustained ALT and body weight decreases. No substantial incremental efficacy was observed with TXR + CVC combination on ALT, body weight, or in histological end points compared with monotherapy.

An individual patient data meta-analysis to determine cut-offs for and confounders of NAFLD-fibrosis staging with magnetic resonance elastography

BACKGROUND & AIMS

We conducted an individual patient data meta-analysis to establish stiffness cut-off values for magnetic resonance elastography (MRE) in staging liver fibrosis and to assess potential confounding factors.

METHODS

A systematic review of the literature identified studies reporting MRE data in patients with NAFLD. Data were obtained from the corresponding authors. The pooled diagnostic cut-off value for the various fibrosis stages was determined in a two-stage meta-analysis. Multilevel modelling methods were used to analyse potential confounding factors influencing the diagnostic accuracy of MRE in staging liver fibrosis.

RESULTS

Eight independent cohorts comprising 798 patients were included in the meta-analysis. The area under the receiver operating characteristic curve (AUROC) for MRE in detecting significant fibrosis was 0.92 (sensitivity, 79%; specificity, 89%). For advanced fibrosis, the AUROC was 0.92 (sensitivity, 87%; specificity, 88%). For cirrhosis, the AUROC was 0.94 (sensitivity, 88%, specificity, 89%). Cut-offs were defined to explore concordance between MRE and histopathology: ≥F2, 3.14 kPa (pretest probability, 39.4%); ≥F3, 3.53 kPa (pretest probability, 24.1%); and F4, 4.45 kPa (pretest probability, 8.7%). In generalized linear mixed model analysis, histological steatohepatitis with higher inflammatory activity (odds ratio 2.448, 95% CI 1.180-5.079, p <0.05) and high gamma-glutamyl transferase (GGT) concentration (>120U/L) (odds ratio 3.388, 95% CI 1.577-7.278, p <0.01] were significantly associated with elevated liver stiffness, and thus affecting accuracy in staging early fibrosis (F0-F1). Steatosis, as measured by magnetic resonance imaging proton density fat fraction, and body mass index(BMI) were not confounders.

CONCLUSIONS

MRE has excellent diagnostic performance for significant, advanced fibrosis and cirrhosis in patients with NAFLD. Elevated inflammatory activity and GGT level may lead to overestimation of early liver fibrosis, but anthropometric measures such as BMI or the degree of steatosis do not.

IMPACT AND IMPLICATIONS

This individual patient data meta-analysis of eight international cohorts, including 798 patients, demonstrated that MRE achieves excellent diagnostic accuracy for significant, advanced fibrosis and cirrhosis in patients with NAFLD. Cut-off values (significant fibrosis, 3.14 kPa; advanced fibrosis, 3.53 kPa; and cirrhosis, 4.45 kPa) were established. Elevated inflammatory activity and gamma-glutamyltransferase level may affect the diagnostic accuracy of MRE, leading to overestimation of liver fibrosis in early stages. We observed no impact of diabetes, obesity, or any other metabolic disorder on the diagnostic accuracy of MRE.

Hepatocytic Ballooning in Non-alcoholic Steatohepatitis: Bridging the Knowledge Gap and Charting Future Avenues

Non-alcoholic steatohepatitis (NASH) is emerging as a significant global health concern, characterized by hepatic lipid accumulation, inflammation, and hepatocellular injury. Hepatocytic ballooning, a histological feature of NASH, has gained prominence for its role in disease progression and potential as a therapeutic target. This review provides an overview of the current knowledge regarding hepatocytic ballooning in NASH, highlighting the key molecular and cellular mechanisms implicated in its development. We delve into the intricate interplay of metabolic dysregulation, oxidative stress, and lipid toxicity as drivers of hepatocytic ballooning, shedding light on the pathways responsible for its initiation and perpetuation. Furthermore, we explore the diagnostic challenges associated with hepatocytic ballooning and its significance as a prognostic indicator in NASH patients. While hepatocytic ballooning holds promise as a therapeutic target, this abstract discusses the various experimental and clinical approaches to ameliorate this histological hallmark. Potential interventions, including lifestyle modifications, pharmacological agents, and emerging therapies, are evaluated in terms of their efficacy and safety profiles. In conclusion, this review underscores the need to bridge the knowledge gap surrounding hepatocytic ballooning in NASH and emphasizes its importance in understanding disease pathogenesis and progression. By charting future research avenues and clinical strategies, we aspire to advance our comprehension of NASH and ultimately improve patient outcomes in this rapidly evolving field of hepatology.

NIS2+™, an optimisation of the blood-based biomarker NIS4® technology for the detection of at-risk NASH: A prospective derivation and validation study

BACKGROUND & AIMS

NIS4® is a blood-based non-invasive test designed to effectively rule in/rule out at-risk non-alcoholic steatohepatitis (NASH), defined as non-alcoholic fatty liver disease activity score ≥4 and significant fibrosis (stage ≥2), among patients with metabolic risk factors. Robustness of non-invasive test scores across characteristics of interest including age, type 2 diabetes mellitus, and sex, and optimised analytical aspects are critical for large-scale implementation in clinical practice. We developed and validated NIS2+™, an optimisation of NIS4®, specifically designed to improve score robustness.

METHODS

A well-balanced training cohort (n = 198) included patients from the GOLDEN-505 trial. The validation (n = 684) and test (n = 2,035) cohorts included patients from the RESOLVE-IT trial. Well-matched subgroups were created to avoid potential confounding effects during modelling and analysis of score robustness. Models were trained using logistic regressions for at-risk NASH detection and compared using Bayesian information criteria. Performance of NIS2+™ was compared with that of NIS4®, Fibrosis-4, and alanine aminotransferase using area under the receiver operating characteristic curve, and robustness was analysed through score distribution.

RESULTS

Using the training cohort to compare all combinations of NIS4® biomarkers, NIS2 (miR-34a-5p, YKL-40) was identified as the best combination of parameters. To correct for the sex effect on miR-34a-5p (validation cohort), sex and sex ∗ miR-34a-5p parameters were added, creating NIS2+™. In the test cohort, NIS2+™ exhibited a statistically higher area under the receiver operating characteristic curve (0.813) vs. NIS4® (0.792; p = 0.0002), Fibrosis-4 (0.653; p <0.0001), and alanine aminotransferase (0.699; p <0.0001). NIS2+™ scores were not affected by age, sex, BMI, or type 2 diabetes mellitus status, providing robust clinical performances irrespective of patient characteristics.

CONCLUSION

NIS2+™ constitutes a robust optimisation of NIS4® technology for the detection of at-risk NASH.

IMPACT AND IMPLICATIONS

The development of non-invasive tests for accurate, large-scale detection of patients with at-risk non-alcoholic steatohepatitis (NASH; defined as NASH with non-alcoholic fatty liver disease activity score ≥4 and fibrosis stage ≥2) - who are at higher risk for disease progression and for developing liver-related life-threatening outcomes - is critical for identifying this patient population in the clinical setting and improving the screening process of NASH clinical trials. We report the development and validation of NIS2+™, a diagnostic test designed as an optimisation of NIS4® technology, a blood-based panel currently used to detect at-risk NASH in patients with metabolic risk factors. NIS2+™ showed improved performance for the detection of at-risk NASH compared with NIS4® and other non-invasive liver tests that was not impacted by patients' characteristics of interest, such as age, sex, type 2 diabetes mellitus, BMI, dyslipidaemia, and hypertension. This makes NIS2+™ a robust and reliable tool for the diagnosis of at-risk NASH among patients with metabolic risk factors, and an effective candidate for large-scale implementation in clinical practice and clinical trials.

Exploring Opportunities to Enhance the Screening and Surveillance of Hepatocellular Carcinoma in Non-Alcoholic Fatty Liver Disease (NAFLD) through Risk Stratification Algorithms Incorporating Ultrasound Elastography

Non-alcoholic fatty liver disease (NAFLD), with its progressive form, non-alcoholic steatohepatitis (NASH), has emerged as a significant public health concern, affecting over 30% of the global population. Hepatocellular carcinoma (HCC), a complication associated with both cirrhotic and non-cirrhotic NAFLD, has shown a significant increase in incidence. A substantial proportion of NAFLD-related HCC occurs in non-cirrhotic livers, highlighting the need for improved risk stratification and surveillance strategies. This comprehensive review explores the potential role of liver ultrasound elastography as a risk assessment tool for HCC development in NAFLD and highlights the importance of effective screening tools for early, cost-effective detection and improved management of NAFLD-related HCC. The integration of non-invasive tools and algorithms into risk stratification strategies could have the capacity to enhance NAFLD-related HCC screening and surveillance effectiveness. Alongside exploring the potential advancement of non-invasive tools and algorithms for effectively stratifying HCC risk in NAFLD, we offer essential perspectives that could enable readers to improve the personalized assessment of NAFLD-related HCC risk through a more methodical screening approach.

Biomarkers for staging fibrosis and non-alcoholic steatohepatitis in non-alcoholic fatty liver disease (the LITMUS project): a comparative diagnostic accuracy study

BACKGROUND

The reference standard for detecting non-alcoholic steatohepatitis (NASH) and staging fibrosis-liver biopsy-is invasive and resource intensive. Non-invasive biomarkers are urgently needed, but few studies have compared these biomarkers in a single cohort. As part of the Liver Investigation: Testing Marker Utility in Steatohepatitis (LITMUS) project, we aimed to evaluate the diagnostic accuracy of 17 biomarkers and multimarker scores in detecting NASH and clinically significant fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) and identify their optimal cutoffs as screening tests in clinical trial recruitment.

METHODS

This was a comparative diagnostic accuracy study in people with biopsy-confirmed NAFLD from 13 countries across Europe, recruited between Jan 6, 2010, and Dec 29, 2017, from the LITMUS metacohort of the prospective European NAFLD Registry. Adults (aged ≥18 years) with paired liver biopsy and serum samples were eligible; those with excessive alcohol consumption or evidence of other chronic liver diseases were excluded. The diagnostic accuracy of the biomarkers was expressed as the area under the receiver operating characteristic curve (AUC) with liver histology as the reference standard and compared with the Fibrosis-4 index for liver fibrosis (FIB-4) in the same subgroup. Target conditions were the presence of NASH with clinically significant fibrosis (ie, at-risk NASH; NAFLD Activity Score ≥4 and F≥2) or the presence of advanced fibrosis (F≥3), analysed in all participants with complete data. We identified thres holds for each biomarker for reducing the number of biopsy-based screen failures when recruiting people with both NASH and clinically significant fibrosis for future trials.

FINDINGS

Of 1430 participants with NAFLD in the LITMUS metacohort with serum samples, 966 (403 women and 563 men) were included after all exclusion criteria had been applied. 335 (35%) of 966 participants had biopsy-confirmed NASH and clinically significant fibrosis and 271 (28%) had advanced fibrosis. For people with NASH and clinically significant fibrosis, no single biomarker or multimarker score significantly reached the predefined AUC 0·80 acceptability threshold (AUCs ranging from 0·61 [95% CI 0·54-0·67] for FibroScan controlled attenuation parameter to 0·81 [0·75-0·86] for SomaSignal), with accuracy mostly similar to FIB-4. Regarding detection of advanced fibrosis, SomaSignal (AUC 0·90 [95% CI 0·86-0·94]), ADAPT (0·85 [0·81-0·89]), and FibroScan liver stiffness measurement (0·83 [0·80-0·86]) reached acceptable accuracy. With 11 of 17 markers, histological screen failure rates could be reduced to 33% in trials if only people who were marker positive had a biopsy for evaluating eligibility. The best screening performance for NASH and clinically significant fibrosis was observed for SomaSignal (number needed to test [NNT] to find one true positive was four [95% CI 4-5]), then ADAPT (six [5-7]), MACK-3 (seven [6-8]), and PRO-C3 (nine [7-11]).

INTERPRETATION

None of the single markers or multimarker scores achieved the predefined acceptable AUC for replacing biopsy in detecting people with both NASH and clinically significant fibrosis. However, several biomarkers could be applied in a prescreening strategy in clinical trial recruitment. The performance of promising markers will be further evaluated in the ongoing prospective LITMUS study cohort.

FUNDING

The Innovative Medicines Initiative 2 Joint Undertaking.

Emerging concepts in the detection of liver fibrosis in non-alcoholic fatty liver disease

INTRODUCTION

The non-invasive identification of liver fibrosis related to Non-Alcoholic Fatty Liver Disease is crucial for risk-stratification of patients. Currently, the reference standard to stage hepatic fibrosis relies on liver biopsy, but multiple approaches are developed to allow for non-invasive diagnosis and risk stratification. Non-invasive tests, including blood-based scores and vibration-controlled transient elastography, have been widely validated and represent a good surrogate for risk stratification according to recent European and American guidelines.

AREAS COVERED

Novel approaches are based on 'liquid' biomarkers of liver fibrogenesis, including collagen-derived markers (PRO-C3 or PRO-C6), or 'multi-omics' technologies (e.g. proteomic-based molecules or miRNA testing), bearing the advantage of tailoring the intrahepatic disease activity. Alternative approaches are based on 'dry' biomarkers, including magnetic resonance-based tools (including proton density fat fraction, magnetic resonance elastography, or corrected T1), which reach similar accuracy of liver histology and will potentially help identify the best candidates for pharmacological treatment of fibrosing non-alcoholic steatohepatitis.

EXPERT OPINION

In the near future, the sequential use of non-invasive tests, as well as the complimentary use of liquid and dry biomarkers according to the clinical need (diagnosis, risk stratification, and prognosis, or treatment response) will guide and improve the management of this liver disease.

Machine learning algorithm improves the detection of NASH (NAS-based) and at-risk NASH: A development and validation study

BACKGROUND AND AIMS

Detecting NASH remains challenging, while at-risk NASH (steatohepatitis and F≥ 2) tends to progress and is of interest for drug development and clinical application. We developed prediction models by supervised machine learning techniques, with clinical data and biomarkers to stage and grade patients with NAFLD.

APPROACH AND RESULTS

Learning data were collected in the Liver Investigation: Testing Marker Utility in Steatohepatitis metacohort (966 biopsy-proven NAFLD adults), staged and graded according to NASH CRN. Conditions of interest were the clinical trial definition of NASH (NAS ≥ 4;53%), at-risk NASH (NASH with F ≥ 2;35%), significant (F ≥ 2;47%), and advanced fibrosis (F ≥ 3;28%). Thirty-five predictors were included. Missing data were handled by multiple imputations. Data were randomly split into training/validation (75/25) sets. A gradient boosting machine was applied to develop 2 models for each condition: clinical versus extended (clinical and biomarkers). Two variants of the NASH and at-risk NASH models were constructed: direct and composite models.Clinical gradient boosting machine models for steatosis/inflammation/ballooning had AUCs of 0.94/0.79/0.72. There were no improvements when biomarkers were included. The direct NASH model produced AUCs (clinical/extended) of 0.61/0.65. The composite NASH model performed significantly better (0.71) for both variants. The composite at-risk NASH model had an AUC of 0.83 (clinical and extended), an improvement over the direct model. Significant fibrosis models had AUCs (clinical/extended) of 0.76/0.78. The extended advanced fibrosis model (0.86) performed significantly better than the clinical version (0.82).

CONCLUSIONS

Detection of NASH and at-risk NASH can be improved by constructing independent machine learning models for each component, using only clinical predictors. Adding biomarkers only improved the accuracy of fibrosis.

Clinical Trial Landscape in NASH

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

Innovative Therapeutic Approaches in Non-Alcoholic Fatty Liver Disease: When Knowing Your Patient Is Key

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disorders ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic steatosis may result from the dysfunction of multiple pathways and thus multiple molecular triggers involved in the disease have been described. The development of NASH entails the activation of inflammatory and fibrotic processes. Furthermore, NAFLD is also strongly associated with several extra-hepatic comorbidities, i.e., metabolic syndrome, type 2 diabetes mellitus, obesity, hypertension, cardiovascular disease and chronic kidney disease. Due to the heterogeneity of NAFLD presentations and the multifactorial etiology of the disease, clinical trials for NAFLD treatment are testing a wide range of interventions and drugs, with little success. Here, we propose a narrative review of the different phenotypic characteristics of NAFLD patients, whose disease may be triggered by different agents and driven along different pathophysiological pathways. Thus, correct phenotyping of NAFLD patients and personalized treatment is an innovative therapeutic approach that may lead to better therapeutic outcomes.

Artificial Intelligence-Based Opportunities in Liver Pathology-A Systematic Review

BACKGROUND

Artificial Intelligence (AI)-based Deep Neural Networks (DNNs) can handle a wide range of applications in image analysis, ranging from automated segmentation to diagnostic and prediction. As such, they have revolutionized healthcare, including in the liver pathology field.

OBJECTIVE

The present study aims to provide a systematic review of applications and performances provided by DNN algorithms in liver pathology throughout the Pubmed and Embase databases up to December 2022, for tumoral, metabolic and inflammatory fields.

RESULTS

42 articles were selected and fully reviewed. Each article was evaluated through the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, highlighting their risks of bias.

CONCLUSIONS

DNN-based models are well represented in the field of liver pathology, and their applications are diverse. Most studies, however, presented at least one domain with a high risk of bias according to the QUADAS-2 tool. Hence, DNN models in liver pathology present future opportunities and persistent limitations. To our knowledge, this review is the first one solely focused on DNN-based applications in liver pathology, and to evaluate their bias through the lens of the QUADAS2 tool.

Future Treatment Options and Regimens for Nonalcoholic Fatty Liver Disease

Recent progress in our understanding of the pathogenic mechanisms that drive progression of nonalcoholic steatohepatitis as well as lessons learned from several clinical trials that have been conducted over the past 15 years guide our current regulatory framework and trial design. Targeting the metabolic drivers should probably be the backbone of therapy in most of the patients, with some requiring more specific intrahepatic antiinflammatory and antifibrotic actions to achieve success. New and innovative targets and approaches as well as combination therapies are currently explored, while awaiting a better understanding of disease heterogeneity that should allow for future individualized medicine.