Pegbelfermin in Patients With Nonalcoholic Steatohepatitis and Compensated Cirrhosis (FALCON 2): A Randomized Phase 2b Study

Target Populations for Novel Triglyceride-Lowering Therapies

Lipoprotein lipase regulates triglyceride hydrolysis and contributes to cellular uptake of triglyceride-rich lipoprotein remnants. Multiple pathways modulate lipoprotein lipase activity, which has prompted interest in the development of drugs that increase lipoprotein lipase activity as means to reduce risk for acute pancreatitis, atherosclerotic cardiovascular disease, and metabolic dysfunction-associated steatohepatitis through reduction of circulating triglycerides and remnant cholesterol. The authors provide an overview of the target populations for agents that lower triglycerides and remnant cholesterol through increased lipoprotein lipase activity, the drugs being developed for these indications, including apolipoprotein C-III and angiopoietin-like protein 3, 3/8, and 4 inhibitors, and the epidemiologic and genetic evidence supporting the use of these drugs for the prevention of atherosclerotic cardiovascular disease and acute pancreatitis. In addition, the authors provide a corresponding overview of fibroblast growth factor-21 analogues that share many characteristics with these novel triglyceride-lowering drugs. Apolipoprotein C-III inhibitors, angiopoietin-like protein 3, 3/8, and 4 inhibitors, and fibroblast growth factor-21 analogues have pronounced triglyceride-lowering and remnant cholesterol-lowering effects. In clinical trials, apolipoprotein C-III inhibitors have been shown to lower risk for acute pancreatitis in patients with severe hypertriglyceridemia and are approved for this indication, while fibroblast growth factor-21 analogues reduce hepatic steatosis and fibrosis in patients with metabolic dysfunction-associated steatohepatitis. It remains to be seen whether these novel drugs may lower risk for atherosclerotic cardiovascular disease as well.

Efruxifermin in Compensated Liver Cirrhosis Caused by MASH

BACKGROUND

In phase 2 trials involving patients with stage 2 or 3 fibrosis caused by metabolic dysfunction-associated steatohepatitis (MASH), efruxifermin, a bivalent fibroblast growth factor 21 (FGF21) analogue, reduced fibrosis and resolved MASH. Data are needed on the efficacy and safety of efruxifermin in patients with compensated cirrhosis (stage 4 fibrosis) caused by MASH.

METHODS

In this phase 2b, randomized, placebo-controlled, double-blind trial, we assigned patients with MASH who had biopsy-confirmed compensated cirrhosis (stage 4 fibrosis) to receive subcutaneous efruxifermin (at a dose of 28 mg or 50 mg once daily) or placebo. The primary outcome was a reduction of at least one stage of fibrosis without worsening of MASH at week 36. Secondary outcomes included the same criterion at week 96.

RESULTS

A total of 181 patients underwent randomization and received at least one dose of efruxifermin or placebo. Of these patients, liver biopsy was performed in 154 patients at 36 weeks and in 134 patients at 96 weeks. At 36 weeks, a reduction in fibrosis without worsening of MASH occurred in 8 of 61 patients (13%) in the placebo group, in 10 of 57 patients (18%) in the 28-mg efruxifermin group (difference from placebo after adjustment for stratification factors, 3 percentage points; 95% confidence interval [CI], -11 to 17; P = 0.62), and in 12 of 63 patients (19%) in the 50-mg efruxifermin group (difference from placebo, 4 percentage points; 95% CI, -10 to 18; P = 0.52). At week 96, a reduction in fibrosis without worsening of MASH occurred in 7 of 61 patients (11%) in the placebo group, in 12 of 57 patients (21%) in the 28-mg efruxifermin group (difference from placebo, 10 percentage points; 95% CI, -4 to 24), and in 18 of 63 patients (29%) in the 50-mg efruxifermin group (difference from placebo, 16 percentage points; 95% CI, 2 to 30). Gastrointestinal adverse events were more common with efruxifermin; most events were mild or moderate.

CONCLUSIONS

In patients with compensated cirrhosis caused by MASH, efruxifermin did not significantly reduce fibrosis at 36 weeks. (Funded by Akero Therapeutics; SYMMETRY ClinicalTrials.gov number, NCT05039450.).

Liver cirrhosis in metabolic dysfunction-associated steatohepatitis

In the present narrative review, we have summarized the current evidence on the natural progression of metabolic dysfunction-associated steatohepatitis (MASH) cirrhosis observed through the placebo arm in clinical trials and observational studies. The outcomes scrutinized throughout our review were histology-related changes, non-invasive fibrosis markers, indicators of decompensation, end-stage hepatic complications, and mortality reported during the different clinical trials. Given the short duration of clinical trials, observational studies were included to obtain better insight into the long-term progression and prognosis of MASH cirrhosis. Lastly, new updates about MASH cirrhosis treatments were listed, and the results of these randomized clinical trials were described to enhance our understanding of our current standing in the treatment of MASH cirrhosis.

Fibroblast growth factor receptor signaling in metabolic dysfunction-associated fatty liver disease: Pathogenesis and therapeutic targets

Metabolic dysfunction-associated fatty liver disease (MAFLD) has emerged as a significant hepatic manifestation of metabolic syndrome, with its prevalence increasing globally alongside the epidemics of obesity and diabetes. MAFLD represents a continuum of liver damage, spanning from uncomplicated steatosis to metabolic dysfunction-associated steatohepatitis (MASH). This condition can advance to more severe outcomes, including fibrosis and cirrhosis. Fibroblast growth factor receptors (FGFRs) are a family of four receptor tyrosine kinases (FGFR1-4) that interact with both paracrine and endocrine fibroblast growth factors (FGFs). This interaction activates the phosphorylation of tyrosine kinase residues, thereby triggering downstream signaling pathways, including RAS-MAPK, JAK-STAT, PI3K-AKT, and PLCγ. In the context of MAFLD, paracrine FGF-FGFR signaling is predominantly biased toward the development of liver fibrosis and carcinogenesis. In contrast, endocrine FGF-FGFR signaling is primarily biased toward regulating the metabolism of bile acids, carbohydrates, lipids, and phosphate, as well as maintaining the overall balance of energy metabolism in the body. The interplay between these biased signaling pathways significantly influences the progression of MAFLD. This review explores the critical functions of FGFR signaling in MAFLD from three perspectives: first, it examines the primary roles of FGFRs relative to their structure; second, it summarizes FGFR signaling in hepatic lipid metabolism, elucidating mechanisms underlying the occurrence and progression of MAFLD; finally, it highlights recent advancements in drug development aimed at targeting FGFR signaling for the treatment of MAFLD and its associated diseases.

FGF-based drug discovery: advances and challenges

The fibroblast growth factor (FGF) family comprises 15 paracrine-acting and 3 endocrine-acting polypeptides, which govern a multitude of processes in human development, metabolism and tissue homeostasis. Therapeutic endocrine FGFs have recently advanced in clinical trials, with FGF19 and FGF21-based therapies on the cusp of approval for the treatment of primary sclerosing cholangitis and metabolic syndrome-associated steatohepatitis, respectively. By contrast, while paracrine FGFs were once thought to be promising drug candidates for wound healing, burns, tissue repair and ischaemic ailments based on their potent mitogenic and angiogenic properties, repeated failures in clinical trials have led to the widespread perception that the development of paracrine FGF-based drugs is not feasible. However, the observation that paracrine FGFs can exert FGF hormone-like metabolic activities has restored interest in these FGFs. The recent structural elucidation of the FGF cell surface signalling machinery and the formulation of a new threshold model for FGF signalling specificity have paved the way for therapeutically harnessing paracrine FGFs for the treatment of a range of metabolic diseases.

Intestinal failure-associated steatosis and fibroblast growth factor 21 plasma levels among adult chronic intestinal failure patients

BACKGROUND & AIMS

Adult patients with chronic intestinal failure (CIF) may develop intestinal failure-associated steatosis. Asymptomatic steatosis can lead to steatohepatitis and its downstream complications. Monitoring steatosis in daily practice in adult CIF patients is hampered by limited, reliable, accessible, non-invasive methods to measure liver fat content (LFC). Fibroblast growth factor 21 (FGF21) is a hormone that is mainly produced by hepatocytes, and higher plasma levels are associated with the presence and the degree of liver steatosis in several clinical conditions. Furthermore, FGF21 analogues have been shown to reduce fatty liver. FGF21 has previously been suggested as a biomarker for liver steatosis. The aim of this study was to assess the diagnostic performance of FGF21 plasma levels to detect steatosis and steatosis severity in adult CIF patients.

METHODS

FGF21 plasma levels were quantified using enzyme-linked immunosorbent assay (ELISA) in 48 adult CIF patients who had been receiving home parenteral nutrition (HPN) or intravenous fluids for ≥3 months for ≥2 times per week. Liver fat content (LFC, %) was assessed with proton magnetic resonance spectroscopy (1H-MRS). Patient characteristics of patients with steatosis (LFC >5.5 %) and without steatosis (LFC ≤5.5 %) were compared using the Mann-Whitney U test or Fisher's exact test. The diagnostic value of FGF21 levels to diagnose the presence of steatosis (LFC >5.5 %) was performed by determining the area under the receiver operating characteristics curve (AUC), and the optimal cut-off value was determined. Furthermore, Spearman's rho correlation coefficient was calculated to evaluate the association between FGF21 levels and LFC.

RESULTS

FGF21 plasma levels were measured in 48 patients (median age of 56 years, 71 % female) with a median duration of HPN use of 57 months. Steatosis was diagnosed in 8/48 (17 %) patients, with a median LFC of 8.4 % (range 5.7-39.9 %). CIF patients with steatosis had higher median FGF21 plasma levels (658 pg/mL) than patients without steatosis (299 pg/mL). The area under the curve (AUC) of FGF21 to predict steatosis (LFC >5.5 %) was 0.80 [95 % CI 0.63, 0.96]. With the optimal FGF21 cut-off point at 453 pg/mL, the sensitivity as well as the specificity was 75 %. The calculated Spearman rho correlation found a significant positive correlation (ρ = 0.65, p < 0.001) between FGF21 plasma levels and LFC (%).

CONCLUSION

Adult CIF patients with steatosis had higher FGF21 plasma levels than CIF patients without steatosis. FGF21 is a good predictor for diagnosing steatosis and has a good correlation with LFC. FGF21 should be considered as a biomarker for steatosis in adult patients with CIF.

Targeting Metabolism: Innovative Therapies for MASLD Unveiled

The recent introduction of the term metabolic-dysfunction-associated steatotic liver disease (MASLD) has highlighted the critical role of metabolism in the disease's pathophysiology. This innovative nomenclature signifies a shift from the previous designation of non-alcoholic fatty liver disease (NAFLD), emphasizing the condition's progressive nature. Simultaneously, MASLD has become one of the most prevalent liver diseases worldwide, highlighting the urgent need for research to elucidate its etiology and develop effective treatment strategies. This review examines and delineates the revised definition of MASLD, exploring its epidemiology and the pathological changes occurring at various stages of the disease. Additionally, it identifies metabolically relevant targets within MASLD and provides a summary of the latest metabolically targeted drugs under development, including those in clinical and some preclinical stages. The review finishes with a look ahead to the future of targeted therapy for MASLD, with the goal of summarizing and providing fresh ideas and insights.

Metabolic-Dysfunction-Associated Steatotic Liver Disease: Molecular Mechanisms, Clinical Implications, and Emerging Therapeutic Strategies

Metabolic-dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is a highly prevalent metabolic disorder characterized by hepatic steatosis in conjunction with at least one cardiometabolic risk factor, such as obesity, type 2 diabetes, hypertension, or dyslipidemia. As global rates of obesity and metabolic syndrome continue to rise, MASLD is becoming a major public health concern, with projections indicating a substantial increase in prevalence over the coming decades. The disease spectrum ranges from simple steatosis to metabolic-dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis, and hepatocellular carcinoma, contributing to significant morbidity and mortality worldwide. This review delves into the molecular mechanisms driving MASLD pathogenesis, including dysregulation of lipid metabolism, chronic inflammation, oxidative stress, mitochondrial dysfunction, and gut microbiota alterations. Recent advances in research have highlighted the role of genetic and epigenetic factors in disease progression, as well as novel therapeutic targets such as peroxisome proliferator-activated receptors (PPARs), fibroblast growth factors, and thyroid hormone receptor beta agonists. Given the multifaceted nature of MASLD, a multidisciplinary approach integrating early diagnosis, molecular insights, lifestyle interventions, and personalized therapies is critical. This review underscores the urgent need for continued research into innovative treatment strategies and precision medicine approaches to halt MASLD progression and improve patient outcomes.

Long-term liver outcomes after metabolic surgery in compensated cirrhosis due to metabolic dysfunction-associated steatohepatitis

No therapy has been shown to reduce the risk of major adverse liver outcomes (MALO) in patients with cirrhosis due to metabolic dysfunction-associated steatohepatitis (MASH). The Surgical Procedures Eliminate Compensated Cirrhosis In Advancing Long-term (SPECCIAL) observational study compared the effects of metabolic surgery and nonsurgical treatment in patients with obesity and compensated histologically proven MASH-related cirrhosis. Using a doubly robust estimation methodology to balance key baseline characteristics between groups, the time-to-incident MALO was compared between 62 patients (68% female) who underwent metabolic surgery and 106 nonsurgical controls (71% female), with a mean follow-up of 10.0 ± 4.5 years. The 15 year cumulative incidence of MALO was 20.9% (95% confidence interval (CI), 2.5-35.9%) in the surgical group compared with 46.4% (95% CI, 25.6-61.3%) in the nonsurgical group, with an adjusted hazard ratio of 0.28 (95% CI, 0.12-0.64), P = 0.003. The 15 year cumulative incidence of decompensated cirrhosis was 15.6% (95% CI, 0-31.3%) in the surgical group compared with 30.7% (95% CI, 12.9-44.8%) in the nonsurgical group, with an adjusted hazard ratio of 0.20 (95% CI, 0.06-0.68), P = 0.01. Among patients with compensated MASH-related cirrhosis and obesity, metabolic surgery, compared with nonsurgical management, was associated with a significantly lower risk of incident MALO. In the absence of approved medical therapies for compensated MASH-related cirrhosis, metabolic surgery may represent a safe and effective therapeutic option to influence the trajectory of cirrhosis.

FGF21 Analogues in Patients With Metabolic Diseases: Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND AND AIMS

Liver-related complications are frequent in patients with metabolic diseases, with limited treatment options currently available. This systematic review and meta-analysis aimed to assess the effect of fibroblast growth factor-21 (FGF21) analogues on hepatic steatosis, inflammation and fibrosis in patients with metabolic diseases.

METHODS

We conducted a systematic literature search in Pubmed, Scopus and Web of Science for randomised controlled trials (RCTs) assessing the effect of FGF21 analogues on hepatic steatosis evaluated by hepatic fat fraction (HFF), inflammation and fibrosis compared to placebo. Adverse events (AEs) were also recorded.

RESULTS

Treatment with FGF21 analogues was associated with metabolic-associated steatohepatitis (MASH) resolution without fibrosis worsening (5 studies, risk ratio [RR] 4.40, 95% confidence interval [CI]: 2.41, 8.03, p < 0.001) and fibrosis improvement by 1 grade without MASH worsening (6 studies, RR 1.79, 95% CI: 1.24, 2.59, p = 0.002). FGF21 analogues significantly lowered HFF compared to placebo (6 studies, SMD -1.08, 95% CI: -1.28, -0.88, p < 0.001), while patients receiving FGF21 analogues were more likely to exhibit a reduction in HFF by 30% (10 studies, RR 4.08, 95% CI: 3.08, 5.40, p < 0.001) or 50% (6 studies, RR 10.43, 95% CI: 5.47, 19.87, p < 0.001). HFF normalisation (≤ 5%) was more frequently achieved with FGF21 analogues (6 studies, RR 14.58, 95% CI: 4.70, 45.18, p < 0.001). The results remained robust after sensitivity analyses. Serious AE and AE leading to drug discontinuation were similar in patients receiving FGF21 analogues or placebo.

CONCLUSIONS

FGF21 analogues can reduce hepatic steatosis, inflammation and fibrosis in patients with metabolic diseases, representing a possible treatment option for steatotic liver disease.

Evaluating the Effectiveness of Pegbelfermin in MASH-Associated Hepatic Fibrosis A Meta-Analysis and Systematic Review of Randomized Controlled Trials

Introduction

Metabolic dysfunction-associated steatohepatitis (MASH), an advanced form of fatty liver disease, is characterized by liver inflammation and fibrosis, with an emerging interest in fibroblast growth factor (FGF)-21 analogs, particularly pegbelfermin (PGBF). This study evaluates the efficacy and safety of PGBF in treating MASH-associated hepatic fibrosis.

Methods

This meta-analysis followed Cochrane guidelines and PRISMA standards. A comprehensive search of databases up to January 2023 focused on randomized controlled trials (RCTs) comparing PGBF to placebo for MASH. Meta-analyses were performed with RevMan 5.4 using a random-effects model.

Results

Data from 452 participants across three RCTs were analyzed. Significant improvements in adiponectin concentration were observed in both the 10 mg [MD = 18.23, 95% CI (6.35, 30.11), p = 0.003] and 20 mg [MD = 18.09, 95% CI (5.88, 30.31), p = 0.004] PGBF groups compared to placebo. Significant reductions in PRO-C3 concentration were noted in both the 10 mg [MD = -25.50, 95% CI (-43.95, -7.05), p = 0.007] and 20 mg [MD = -19.54, 95% CI (-33.33, -5.76), p = 0.005] groups. Significant improvement in MASH was seen in the 10 mg group [RR = 2.84, 95% CI (1.18, 6.78), p = 0.02] but not in the 20 mg group. No significant improvements in liver stiffness, Modified Ishak scores, collagen proportionate area, ALT and AST levels, or treatment-emergent adverse events (TEAEs) were observed in either dosage group.

Conclusions

Pegbelfermin, a promising therapy for MASH fibrosis, has demonstrated effectiveness at 10 mg, significantly improving MASH and biomarkers including adiponectin and PRO-C3, while maintaining a generally safe profile.

Meta-Analysis of Placebo-Treated Patients: Dropout Rates From Treatment in MASH Randomised Controlled Trials

BACKGROUND

Dropout is common and affects the statistical power and randomization balance of randomised controlled trials (RCTs).

AIMS

To estimate the dropout rate in RCTs of metabolic dysfunction-associated steatohepatitis (MASH) and to examine factors associated with dropout in placebo-treated participants.

METHODS

PubMed and Cochrane databases were searched for phase 2-4 MASH RCTs with placebo arms through November 24, 2024. Dropout was defined as the attrition of patients included in the intention-to-treat analysis but did not complete treatment. RCTs were qualitatively reviewed to assess the expected and observed dropouts. Generalised linear mixed model was used to estimate pooled dropout rates.

RESULTS

Sixty RCTs with 3230 placebo-treated participants with MASH were analysed. Thirty-three RCTs reported the dropout rate used to estimate the effect size. Of these, 60.6%, 36.4%, and 3.0% had an expected dropout rate that was higher, lower, and similar, respectively, than the observed dropout rate in the placebo arm. Overall, the dropout rate was 11.06% (95% confidence interval [CI] 9.07 to 13.42), with a higher rate in phase 3-4 trials than in phase 2 trials. The corresponding rates due to adverse events, loss to follow-up and patient choice were 2.41% (95% CI 1.67 to 3.48), 1.79% (95% CI 1.06 to 2.99) and 4.06% (95% CI 2.97 to 5.53), respectively. Meta-regression determined that the dropout rate increased with longer treatment duration.

CONCLUSION

Placebo dropout in MASH RCTs is significant, mainly due to patient choice. Factors such as trial phase and treatment duration should be considered when calculating sample size in future clinical trials.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

Metabolic dysfunction-associated steatotic liver disease: heterogeneous pathomechanisms and effectiveness of metabolism-based treatment

The global epidemic of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing worldwide. People with MASLD can progress to cirrhosis and hepatocellular carcinoma and are at increased risk of developing type 2 diabetes, cardiovascular disease, chronic kidney disease, and extrahepatic cancers. Most people with MASLD die from cardiac-related causes. This outcome is attributed to the shared pathogenesis of MASLD and cardiometabolic diseases, involving unhealthy dietary habits, dysfunctional adipose tissue, insulin resistance, and subclinical inflammation. In addition, the steatotic and inflamed liver affects the vasculature and heart via increased glucose production and release of procoagulant factors, dyslipidaemia, and dysregulated release of hepatokines and microRNAs. However, there is substantial heterogeneity in the contributors to the pathophysiology of MASLD, which might influence its rate of progression, its relationship with cardiometabolic diseases, and the response to therapy. The most effective non-pharmacological treatment approaches for people with MASLD include weight loss. Paradoxically, some effective pharmacological approaches to improve liver health in people with MASLD are associated with no change in bodyweight or even with weight gain, and similar response heterogeneity has been observed for changes in cardiometabolic risk factors. In this Review, we address the heterogeneity of MASLD with respect to its pathogenesis, outcomes, and metabolism-based treatment responses. Although there is currently insufficient evidence for the implementation of precision medicine for risk prediction, prevention, and treatment of MASLD, we discuss whether knowledge about this heterogeneity might help achieving this goal in the future.

Causal effects of circulating inflammatory proteins on oral phenotypes: Deciphering immune-mediated profiles in the host-oral axis

BACKGROUND

Oral manifestations function as precursors to potential systemic pathologies, signaling early indicators of underlying health complications or immunological dysfunctions. Within these dynamics, circulating inflammatory proteins are recognized as critical mediators in immunopharmacology, bridging holistic health, immune response, and oral health.

METHODS

We employed genetic data from genome-wide association studies to perform comprehensive Mendelian randomization (MR) analyses on 91 circulating inflammatory proteins and 17 oral phenotypes. Six MR algorithms and five auxiliary control measures were utilized to estimate the causal effects. Subsequently, the MR-Bayesian model averaging (MR-BMA) approach was conducted to elucidate the priorities in host-oral communication, followed by network analyses to explore the interactions among phenotypes.

RESULTS

After multiple corrections, MR identified five genetically predicted proteins associated with oral phenotypes. Specifically, FGF21 was correlated with Nteeth and DMFS; hGDNF with gingival pain; CCL4 with stomatitis; and S100A12 with denture use. The causal associations remained robust in sensitivity analyses. Nine protein-phenotype clusters were prioritized using MR-BMA. Among these, S100A12, FGF19, FGF21, and CCL4 exhibited extensive correlations with various oral phenotypes.

CONCLUSIONS

Our study offers novel genetic insights into the causal relationships, prioritizations, and connections between circulating inflammatory proteins and oral phenotypes. These findings comprehensively depict immune-mediated proteomic profiles underlying the host-oral axis, providing significant implications for clinical practice, public health, and immunopharmacology.

Targeting Fibrosis: From Molecular Mechanisms to Advanced Therapies

As the final stage of disease-related tissue injury and repair, fibrosis is characterized by excessive accumulation of the extracellular matrix. Unrestricted accumulation of stromal cells and matrix during fibrosis impairs the structure and function of organs, ultimately leading to organ failure. The major etiology of fibrosis is an injury caused by genetic heterogeneity, trauma, virus infection, alcohol, mechanical stimuli, and drug. Persistent abnormal activation of "quiescent" fibroblasts that interact with or do not interact with the immune system via complicated signaling cascades, in which parenchymal cells are also triggered, is identified as the main mechanism involved in the initiation and progression of fibrosis. Although the mechanisms of fibrosis are still largely unknown, multiple therapeutic strategies targeting identified molecular mechanisms have greatly attenuated fibrotic lesions in clinical trials. In this review, the organ-specific molecular mechanisms of fibrosis is systematically summarized, including cardiac fibrosis, hepatic fibrosis, renal fibrosis, and pulmonary fibrosis. Some important signaling pathways associated with fibrosis are also introduced. Finally, the current antifibrotic strategies based on therapeutic targets and clinical trials are discussed. A comprehensive interpretation of the current mechanisms and therapeutic strategies targeting fibrosis will provide the fundamental theoretical basis not only for fibrosis but also for the development of antifibrotic therapies.

Reversion of metabolic dysfunction-associated steatohepatitis by skeletal muscle-directed FGF21 gene therapy

The highly prevalent metabolic dysfunction-associated steatohepatitis (MASH) is associated with liver steatosis, inflammation, and hepatocyte injury, which can lead to fibrosis and may progress to hepatocellular carcinoma and death. New treatment modalities such as gene therapy may be transformative for MASH patients. Here, we describe that one-time intramuscular administration of adeno-associated viral vectors of serotype 1 (AAV1) encoding native fibroblast growth factor 21 (FGF21), a key metabolic regulator, resulted in sustained increased circulating levels of the factor, which mediated long-term (>1 year) MASH and hepatic fibrosis reversion and halted development of liver tumors in obese male and female mouse models. AAV1-FGF21 treatment also counteracted obesity, adiposity, and insulin resistance, which are significant drivers of MASH. Scale-up to large animals successfully resulted in safe skeletal muscle biodistribution and biological activity in key metabolic tissues. Moreover, as a step toward the clinic, circulating FGF21 levels were characterized in obese, insulin-resistant and MASH patients. Overall, these results underscore the potential of the muscle-directed AAV1-FGF21 gene therapy to treat MASH and support its clinical translation.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Drug treatment for metabolic dysfunction-associated steatotic liver disease: Progress and direction

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

β-Klotho as novel therapeutic target in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A narrative review

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) represents the most frequent cause of hepatic disorder, and its progressive form defined as Metabolic Dysfunction-Associated Steatohepatitis (MASH) contributes to the development of fibrosis/cirrhosis and hepatocellular carcinoma (HCC). Today effective therapeutic strategies addressing MASH-related comorbidities, inflammation, and fibrosis are needed. The fibroblast growth factor (FGF) 19 and 21 and their fibroblast growth factor receptor/β-Klotho (KLB) complexes have recently emerged as promising druggable targets for MASLD. However, less is known regarding the causative association between KLB activity and advanced stages of liver disease. In the present narrative review, we aimed to provide an up-to-date picture of the role of the KLB co-receptor in MASLD development and progression. We performed a detailed analysis of recently published preclinical and clinical data to decipher the molecular mechanisms underlying KLB function and to correlate the presence of inherited or acquired KLB aberrancies with the predisposition towards MASLD. Moreover, we described ongoing clinical trials evaluating the therapeutic approaches targeting FGF19-21/FGFR/KLB in patients with MASLD and discussed the challenges related to their use. We furtherly described that KLB exhibits protective effects against metabolic disorders by acting in an FGF-dependent and independent manner thus triggering the hypothesis that KLB soluble forms may play a critical role in preserving liver health. Therefore, targeting KLB may provide promising strategies for treating MASLD, as supported by experimental evidence and ongoing clinical trials.

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.

Efficacy and Safety of Fibroblast Growth Factor 21 Analogues for Metabolic Dysfunction-Associated Steatohepatitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Fibroblast growth factor 21 (FGF21) analogues may benefit patients with metabolic dysfunction-associated steatohepatitis (MASH). We aimed to compare the efficacy and safety of FGF21 analogues versus placebo for treating patients with MASH in randomized controlled trials (RCTs).

METHODS

We searched PubMed, Embase, and the Cochrane Library. Primary outcomes were fibrosis improvement ≥1 stage without worsening of MASH and MASH resolution without worsening of fibrosis. Secondary outcomes were relative reduction ≥30% of the hepatic fat fraction (HFF) measured by magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) and adverse events (AEs).

RESULTS

We included 7 RCTs (886 patients). FGF21 analogues had a higher probability of fibrosis improvement ≥1 stage without worsening of MASH (RR: 1.54; 95% CI: 1.07, 2.22), MASH resolution without worsening of fibrosis (RR: 3.31; 95% CI: 1.80, 6.06), and reduction ≥30% in the HFF by MRI-PDFF (RR: 3.03; 95% CI: 2.12, 4.33) than placebo, without significant difference in the risk of AEs. Subgroup analyses by the stage of fibrosis showed that FGF21 analogues improved fibrosis only among patients with fibrosis stages F1-F3.

CONCLUSION

FGF21 analogues appear to be an effective and safe treatment option for patients with MASH, although the impact on fibrosis improvement may be limited to non-cirrhotic patients.

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

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

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

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

The role of nonmyocardial cells in the development of diabetic cardiomyopathy and the protective effects of FGF21: a current understanding

Diabetic cardiomyopathy (DCM) represents a unique myocardial disease originating from diabetic metabolic disturbances that is characterized by myocardial fibrosis and diastolic dysfunction. While recent research regarding the pathogenesis and treatment of DCM has focused primarily on myocardial cells, nonmyocardial cells-including fibroblasts, vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and immune cells-also contribute significantly to the pathogenesis of DCM. Among various therapeutic targets, fibroblast growth factor 21 (FGF21) has been identified as a promising agent because of its cardioprotective effects that extend to nonmyocardial cells. In this review, we aim to elucidate the role of nonmyocardial cells in DCM and underscore the potential of FGF21 as a therapeutic strategy for these cells.

Exploring endocrine FGFs - structures, functions and biomedical applications

The family of fibroblast growth factors (FGFs) consists of 22 members with diverse biological functions in cells, from cellular development to metabolism. The family can be further categorized into three subgroups based on their three modes of action. FGF19, FGF21, and FGF23 are endocrine FGFs that act in a hormone-like/endocrine manner to regulate various metabolic activities. However, all three members of the endocrine family require both FGF receptors (FGFRs) and klotho co-receptors to elicit their functions. α-klotho and β-klotho act as scaffolds to bring endocrine FGFs closer to their receptors (FGFRs) to form active complexes. Numerous novel studies about metabolic FGFs' structures, mechanisms, and physiological insights have been published to further understand the complex molecular interactions and physiological activities of endocrine FGFs. Herein, we aim to review the structures, physiological functions, binding mechanisms to cognate receptors, and novel biomedical applications of endocrine FGFs in recent years.

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

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

Development of Zalfermin, a Long-Acting Proteolytically Stabilized FGF21 Analog

Here, we describe the development of the FGF21 analog zalfermin (NNC0194-0499, 15), intended for once-weekly sc dosing. Protein engineering was needed to address inherent druggability issues of the natural FGF21 hormone. Thus, deamidation of Asp121 was solved by mutation to glutamine, and oxidation of Met168 was solved by mutation to leucine. N-terminal region degradation by dipeptidyl peptidase IV was prevented by alanine residue elongation. To prevent inactivating metabolism by fibroblast activation protein and carboxypeptidase-like activity in the C-terminal region, and to achieve t1/2 extension (53 h in cynomolgus monkeys), we introduced a C18 fatty diacid at the penultimate position 180. The fatty diacid binds albumin in a reversible manner, such that the free fraction of zalfermin potently activates the FGF-receptor complex and retains receptor selectivity compared with FGF21, providing strong efficacy on body weight loss in diet-induced obese mice. Zalfermin is currently being clinically evaluated for the treatment of metabolic dysfunction-associated steatohepatitis.

The endocrine FGFs axis: A systemic anti-fibrotic response that could prevent pulmonary fibrogenesis?

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease for which therapeutic options are limited, with an unmet need to identify new therapeutic targets. IPF is thought to be the consequence of repeated microlesions of the alveolar epithelium, leading to aberrant epithelial-mesenchymal communication and the accumulation of extracellular matrix proteins. The reactivation of developmental pathways, such as Fibroblast Growth Factors (FGFs), is a well-described mechanism during lung fibrogenesis. Secreted FGFs with local paracrine effects can either exert an anti-fibrotic or a pro-fibrotic action during this pathological process through their FGF receptors (FGFRs) and heparan sulfate residues as co-receptors. Among FGFs, endocrine FGFs (FGF29, FGF21, and FGF23) play a central role in the control of metabolism and tissue homeostasis. They are characterized by a low affinity for heparan sulfate, present in the cell vicinity, allowing them to have endocrine activity. Nevertheless, their interaction with FGFRs requires the presence of mandatory co-receptors, alpha and beta Klotho proteins (KLA and KLB). Endocrine FGFs are of growing interest for their anti-fibrotic action during liver, kidney, or myocardial fibrosis. Innovative therapies based on FGF19 or FGF21 analogs are currently being studied in humans during liver fibrosis. Recent data report a similar anti-fibrotic action of endocrine FGFs in the lung, suggesting a systemic regulation of the pulmonary fibrotic process. In this review, we summarize the current knowledge on the protective effect of endocrine FGFs during the fibrotic processes, with a focus on pulmonary fibrosis.

Efficacy and Safety of Fibroblast Growth Factor-21 Analogs for the Treatment of Metabolic Dysfunction-Associated Steatohepatitis: A Systematic Review and Meta-Analysis

Fibroblast growth factor (FGF)-21 analogs are potential therapeutic candidates for metabolic dysfunction-associated steatohepatitis (MASH). This systematic review and meta-analysis aimed to assess the efficacy and safety of the FGF-21 analogs, efruxifermin, pegbelfermin, and pegozafermin for MASH treatment. A comprehensive systematic review and meta-analysis of randomized controlled trials from five major databases was conducted. Primary efficacy outcomes focused on liver histological improvement, while secondary efficacy outcomes encompassed reductions in liver fat content and improvements in biochemical parameters. Safety outcomes examined included treatment-emergent adverse events (TEAEs), treatment-related TEAEs, TEAEs leading to discontinuation, and serious TEAEs. Eight eligible studies involving 963 patients were included in this review. Compared with the placebo group, the FGF-21 analog-treated group exhibited significantly improved primary efficacy outcomes, specifically ≥1 stage improvement in fibrosis with no worsening of MASH (risk ratio [RR] = 1.83; 95% confidence interval [CI] = 1.27-2.62) and at least two-point improvement in the non-alcoholic fatty liver disease activity score with no worsening of fibrosis (RR = 2.85; 95% CI = 2.06-3.95). Despite an increased risk of TEAEs (RR = 1.17; 95% CI = 1.08-1.27) and treatment-related adverse events (RR = 1.75; 95% CI = 1.40-2.19), FGF-21 analogs exhibited an acceptable safety profile. FGF-21 analogs were significantly better in achieving liver histological improvements and beneficial biochemical outcomes compared with placebo, with a tolerable safety pattern. These findings shed light on the efficacy and safety of FGF-21 analogs and provide valuable evidence for their application as MASH therapeutics.

Pharmacotherapeutic options for metabolic dysfunction-associated steatotic liver disease: where are we today?

INTRODUCTION

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined by hepatic steatosis and cardiometabolic risk factors like obesity, type 2 diabetes, and dyslipidemia. Persistent metabolic injury may promote inflammatory processes resulting in metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis. Mechanistic insights helped to identify potential drug targets, thereby supporting the development of novel compounds modulating disease drivers.

AREAS COVERED

The U.S. Food and Drug Administration has recently approved the thyroid hormone receptor β-selective thyromimetic resmetirom as the first compound to treat MASH and liver fibrosis. This review provides a comprehensive overview of current and potential future pharmacotherapeutic options and their modes of action. Lessons learned from terminated clinical trials are discussed together with the first results of trials investigating novel combinational therapeutic approaches.

EXPERT OPINION

Approval of resmetirom as the first anti-MASH agent may revolutionize the therapeutic landscape. However, long-term efficacy and safety data for resmetirom are currently lacking. In addition, heterogeneity of MASLD reflects a major challenge to define effective agents. Several lead compounds demonstrated efficacy in reducing obesity and hepatic steatosis, while anti-inflammatory and antifibrotic effects of monotherapy appear less robust. Better mechanistic understanding, exploration of combination therapies, and patient stratification hold great promise for MASLD therapy.

Current status and future perspectives of FGF21 analogues in clinical trials

Recent advances in fibroblast growth factor 21 (FGF21) biology and pharmacology have led to the development of several long-acting FGF21 analogues and antibody-based mimetics now in various phases of clinical trials for the treatment of obesity-related metabolic comorbidities. The efficacy of these FGF21 analogues/mimetics on glycaemic control and weight loss is rather mild and inconsistent; nevertheless, several promising therapeutic benefits have been reproducibly observed in most clinical studies, including amelioration of dyslipidaemia (particularly hypertriglyceridaemia) and hepatic steatosis, reduction of biomarkers of liver fibrosis and injury, and resolution of metabolic dysfunction-associated steatohepatitis (MASH). Evidence is emerging that combination therapy with FGF21 analogues and other hormones (such as glucagon-like peptide 1; GLP-1) can synergise their pharmacological benefits, thus maximising the therapeutic efficacy for obesity and its comorbidities.

Advancements in pharmacological treatment of NAFLD/MASLD: a focus on metabolic and liver-targeted interventions

In the present narrative review, we have summarized evidence on the pharmacological treatment of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction-associated steatotic liver disease (MASLD). We start by reviewing the epidemiology of the condition and its close association with obesity and type 2 diabetes. We then discuss how randomized-controlled trials are performed following guidance from regulatory agencies, including differences and similarities between requirements of the US Food and Drug Administration and the European Medicine Agency. Difficulties and hurdles related to limitations of liver biopsy, a large number of screening failures in recruiting patients, as well as unpredictable response rates in the placebo group are evaluated. Finally, we recapitulate the strategies employed for potential drug treatments of this orphan condition. The first is to repurpose drugs that originally targeted T2DM and/or obesity, such as pioglitazone, glucagon-like peptide 1 receptor agonists (liraglutide and semaglutide), multi-agonists (tirzepatide and retatrutide), and sodium-glucose transporter 2 inhibitors. The second is to develop drugs specifically targeting NAFLD/MASLD. Among those, we focused on resmetirom, fibroblast growth factor 21 analogs, and lanifibranor, as they are currently in Phase 3 of their clinical trial development. While many failures have characterized the field of pharmacological treatment of NAFLD/MASLD in the past, it is likely that approval of the first treatments is near. As occurs in many chronic conditions, combination therapy might lead to better outcomes. In the case of non-alcoholic steatohepatitis, we speculate that drugs treating underlying metabolic co-morbidities might play a bigger role in the earlier stages of disease, while liver-targeting molecules will become vital in patients with more advanced disease in terms of inflammation and fibrosis.

Pegbelfermin for reducing transaminase levels in patients with non-alcoholic steatohepatitis: a dose-response meta-analysis of randomized controlled trials

Background

The efficacy of Pegbelfermin (PGBF) in treating non-alcoholic steatohepatitis (NASH) remains controversial. Therefore, we conducted a dose-response meta-analysis to explore the effect and pattern of PGBF at different dosages and treatment durations on transaminase reduction in NASH patients.

Methods

We conducted searches on PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov, and supplemented the search with gray literature and manual searches. Randomized controlled trials (RCTs) evaluating the efficacy of PGBF in NASH patients were included. Risk of bias was assessed by Cochrane Risk of Bias Tool 2.0. We used random-effects models, generalized least squares regression, constrained maximum likelihood, and restricted cubic splines to explore the dose-response relationship. Egger's linear regression was employed to assess publication bias. The study is registered with PROSPERO, CRD42023448024.

Results

Four RCT studies from the period 2018-2023, involving 546 participants, were included. No participants discontinued PGBF treatment due to adverse events. High-dose PGBF treatment significantly reduced transaminase levels in NASH patients compared to the low-dose group (ALT %: MD = 14.94, 95% CI = 2.11-27.77; AST %: MD = 9.05, 95% CI = 3.17-14.92). Longer treatment duration further decreased transaminase levels (ALT%: MD = 8.81, 95% CI = 4.07-13.56; AST%: MD = 6.72, 95% CI = 2.62-10.81). Egger's test did not reveal significant publication bias (p > 0.05). Further investigation indicated a ceiling effect of PGBF dosage on transaminase reduction at 30 mg/week, and NASH patients experienced a rebound in transaminase levels after 28 weeks of continuous treatment.

Conclusion

There is a positive correlation between PGBF dosage and transaminase reduction within a certain range, showing an overall non-linear dose-response relationship. This finding provides guidance for the clinical application of PGBF. Clinicians should be mindful of the dosage ceiling at 30 mg/week and monitor changes in transaminase levels after 28 weeks for timely adjustments in PGBF dosage.

Systematic review registration

PROSPERO, CRD42023448024. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=448024.

Meta-analysis: Efficacy and safety of fibroblast growth factor 21 analogues for the treatment of non-alcoholic steatohepatitis and non-alcoholic steatohepatitis-related fibrosis

BACKGROUND

Fibroblast growth factor 21 (FGF21) analogues have emerged as promising therapeutic targets for non-alcoholic steatohepatitis (NASH). However, the effects and safety of these analogues on NASH and NASH-related fibrosis remain unexplored.

AIMS

To estimate the efficacy and safety of FGF21 analogues for treating NASH and NASH-related fibrosis.

METHODS

PubMed, Embase, and the Cochrane Library were searched for relevant studies up to 11 October 2023. Primary outcomes were defined as the fibrosis improvement ≥1 stage without worsening of NASH and NASH resolution without worsening fibrosis. Secondary outcomes included biomarkers of fibrosis, liver injury, and metabolism. Treatment-related adverse events were also analysed.

RESULTS

Nine studies, including 1054 patients with biopsy-proven NASH and stage F1-F4 fibrosis, were identified. Seven studies reported histological outcomes. The relative risk (RR) for obtaining fibrosis improvement ≥1 stage efficacy was 1.79 (95% CI 1.29-2.48, I2  = 37%, p < 0.001) with FGF21 analogues relative to placebo. Although no statistically significant difference was observed between FGF21 analogues in NASH resolution, sensitivity analyses and fragility index suggest that this result is unstable. The drugs improved hepatic fat fraction (HFF), along with other biomarkers of fibrosis, liver injury, and metabolism (MRE, LSM, Pro-C3, ELF, ALT, AST, TG, HDL-C, and LDL-C). Additionally, no significant difference in serious adverse event incidence rate was observed (RR = 1.26, 95% CI 0.82-1.94, I2  = 24%, p = 0.3).

CONCLUSIONS

FGF21 analogues appear as promising agents for the treatment of NASH and NASH-related fibrosis, and they generally seem to be safe and well tolerated.

Comparative Efficacy of Drug Interventions on NAFLD Over 24 Weeks: A Traditional and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD), currently referred to as metabolic dysfunction-associated steatotic liver disease (MASLD), affects approximately 38% of the world's population, yet no pharmacological therapies have been approved for treatment. We conducted a traditional and network meta-analysis to comprehensively assess the effectiveness of drug regimens on NAFLD, and continued to use the old terminology for consistency.

METHODS

Randomized, placebo-controlled trials (RCTs) investigating drug therapy in an adult population diagnosed with NAFLD with or without diabetes mellitus were included. We assessed the quality of RCTs via the Risk of Bias 2 (ROB 2) tool. When I2 < 50%, we chose a random-effects model, otherwise a fixed-effects model was selected. A random effects model was applied in the network meta-analysis. The odds ratio (OR), weighted mean difference (WMD) or standard mean difference (SMD) with 95% confidence interval (CI) were used for outcome evaluation. The primary endpoint was the resolution of nonalcoholic steatohepatitis (NASH) without the worsening of liver fibrosis. Other endpoints included histological findings and metabolic changes. The PROSPERO Registration ID was CRD42023404309.

RESULTS

Thiazolidinediones (TZDs), vitamin E plus pioglitazone, glucagon-like peptide-1 (GLP-1) receptor agonists and fibroblast growth factor-21 (FGF-21) analogue had a higher surface under the cumulative ranking curve (SUCRA = 76.6, 73.0, 72.0 and 71.6) regarding NASH resolution. Improvement of liver fibrosis stage (≥ 1) was observed with obeticholic acid 25 mg/day (OR 2.01, 95% CI 1.35-2.98), lanifibranor 1200 mg/day (OR 2.39, 95% CI 1.19-4.82) and silymarin (OR 4.54, 95% CI 1.18-17.43) in traditional meta-analysis.

CONCLUSIONS

The results of the comprehensive analysis suggested hypoglycemic drug therapy as an effective intervention for NAFLD, with or without diabetes mellitus. A prioritized selection of TZDs, vitamin E plus pioglitazone, GLP-1 receptor agonists and FGF-21 analogue may be considered for NASH resolution. Obeticholic acid, lanifibranor and silymarin could be considered for the improvement of liver fibrosis. Each medication was relatively safe compared with placebo.

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.

MASLD treatment-a shift in the paradigm is imminent

MASLD prevalence is growing towards the leading cause of end-stage liver disease. Up to today, the most effective treatment is weight loss. Weight loss interventions are moving from lifestyle changes to bariatric surgery or endoscopy, and, more recently, to a new wave of anti-obesity drugs that can compete with bariatric surgery. Liver-targeted therapy is a necessity for those patients who already present liver fibrosis. The field is moving fast, and in the near future, we will testify to a disruptive change in MASLD treatment, similar to the paradigm-shift that occurred for hepatitis C almost one decade ago with direct antiviral agents.

Efruxifermin, an investigational treatment for fibrotic or cirrhotic non-alcoholic steatohepatitis (NASH)

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease and strongly associated with metabolic disorders: obesity, type 2 diabetes (T2D), cardiovascular disease. Persistent metabolic injury results in inflammatory processes leading to nonalcoholic steatohepatitis (NASH), liver fibrosis and ultimately cirrhosis. To date, no pharmacologic agent is approved for the treatment of NASH. Fibroblast growth factor 21 (FGF21) agonism has been linked to beneficial metabolic effects ameliorating obesity, steatosis and insulin resistance, supporting its potential as a therapeutic target in NAFLD.

AREAS COVERED

Efruxifermin (EFX, also AKR-001 or AMG876) is an engineered Fc-FGF21 fusion protein with an optimized pharmacokinetic and pharmacodynamic profile, which is currently tested in several phase 2 clinical trials for the treatment of NASH, fibrosis and compensated liver cirrhosis. EFX improved metabolic disturbances including glycemic control, showed favorable safety and tolerability, and demonstrated antifibrotic efficacy according to FDA requirements for phase 3 trials.

EXPERT OPINION

While some other FGF-21 agonists (e.g. pegbelfermin) are currently not further investigated, available evidence supports the development of EFX as a promising anti-NASH drug in fibrotic and cirrhotic populations. However, antifibrotic efficacy, long-term safety and benefits (i.e. cardiovascular risk, decompensation events, disease progression, liver transplantation, mortality) remain to be determined.