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

Targeting fibroblast growth factor (FGF)-21: a promising strategy for metabolic dysfunction-associated steatotic liver disease treatment

Metabolic dysfunction-associated steatitic liver disease (MASLD) is the predominant chronic liver disease, with its incidence increasing year by year. It has emerged as the most rapidly increasing contributor to liver-related mortality worldwide and is becoming a principal cause of end-stage liver disorders, primarily cancer of the liver and liver transplantation, hence putting a substantial economic burden on public health. The approval of Resmetirom signifies significant advancement in the treatment of metabolic dysfunction-associated steatohepatitis (MASH); nonetheless, the heterogeneity of MASLD renders it challenging for a single medication to address the requirements of all patients. Consequently, it is essential to formulate varied therapeutic approaches for distinct pathogenic causes and phases of disease. Fibroblast growth factor 21 (FGF21), a member of the fibroblast growth factor family, plays a positive and protective role in MASLD. It attenuates hepatic steatosis and lipotoxicity, ameliorates insulin resistance (IR), reduces oxidative stress, endoplasmic reticulum (ER) stress, and inflammation, as well as possesses anti-fibrotic effects. As a result, FGF21 has the potential to treat MASLD. In this review, we will address the possible mechanisms of FGF21 therapy for MASLD to facilitate the development of clinical therapies targeting FGF21 for MASLD.

A Novel Recombinant Human FGF21 Analog with High Glycosylation Has a Prolonged Half-Life and Affects Glycemic and Body Weight Control

Fibroblast growth factor 21 (FGF21), a hormone-like protein, plays a crucial role in enhancing glucose and lipid metabolism, offering promising therapeutic avenues for conditions such as nonalcoholic steatohepatitis and severe hypertriglyceridemia. Despite its potential, this protein's limited stability and brief half-life pose significant challenges for its use in clinical settings. In this study, we created an FGF21 analog (named FGF21-164) that is a mutant of FGF21 and fused it with the tandem repeat sequence of human CD164. FGF21-164, characterized by extensive glycosylation and sialylation, exhibits enhanced pharmacokinetic properties, particularly in terms of its significantly longer half-life compared to its native form. The in vitro efficacy of FGF21-164 was evaluated using 3T3-L1-induced adipocytes. The protein demonstrated a dose-dependent increase in glucose uptake and effectively decreased lipid droplet accumulation surrounding the adipocytes. The in vivo activity of FGF21-164 was evaluated in leptin-deficient (ob/ob) and diet-induced obesity (DIO) mice. A single subcutaneous dose of FGF21-164 led to a rapid decrease in blood glucose levels and sustained normal fasting glucose levels for up to 28 days. Additionally, repeated dosing of FGF21-164 significantly curbed weight gain and reduced hepatic fat accumulation in DIO mice.

Drug Pipeline for MASLD: What Can Be Learned from the Successful Story of Resmetirom

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, metabolic dysfunction-associated steatohepatitis (MASH), represent a growing global health problem linked to obesity, insulin resistance, and dyslipidemia. MASLD often leads to fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, therapeutic options are limited, emphasizing the need for novel, targeted pharmacological interventions. Resmetirom, a selective thyroid hormone receptor beta (THR-β) agonist, offers a promising approach by specifically enhancing hepatic metabolism while minimizing systemic effects. Clinical trials have demonstrated its capacity to reduce hepatic triglyceride accumulation and improve lipid profiles. Early- and advanced-phase studies, including the MAESTRO program, highlight significant reductions in hepatic fat content and favorable impacts on noninvasive biomarkers of fibrosis with minimal side effects. This review highlights evidence from pivotal studies, explores resmetirom's mechanism of action, and compares its efficacy and safety with other emerging therapeutic agents. While resmetirom marks a breakthrough in non-cirrhotic MASH management, further long-term studies are essential to fully evaluate its clinical benefits and potential regulatory approval for broader use in MASLD and MASH.

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.

Hypertriglyceridemia Therapy: Past, Present and Future Perspectives

Hypertriglyceridemia therapy is essential for preventing cardiovascular diseases. Fibrates belong to an important class of lipid-lowering drugs useful for the management of dyslipidaemia. By acting on the peroxisome proliferator-activated receptor (PPAR)-α, these drugs lower serum triglyceride levels and raise high-density lipoprotein cholesterol. Fibrate monotherapy is associated with a risk of myopathy and this risk is enhanced when these agents are administered together with statins. However, whereas gemfibrozil can increase plasma concentrations of statins, fenofibrate has less influence on the pharmacokinetics of statins. Pemafibrate is a new PPAR-α-selective drug considered for therapy, and clinical trials are ongoing. Apart from this class of drugs, new therapies have emerged with different mechanisms of action to reduce triglycerides and the risk of cardiovascular diseases.

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.

Epidemiology, screening, and co-management of type 2 diabetes mellitus and metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as NAFLD, is increasingly recognized as a prevalent global burden. Type 2 diabetes mellitus (T2DM), another important metabolic disease, is considered a major contributor to the development of MASLD. MASLD and T2DM have a strong association with each other due to shared pathogenic mechanisms. The co-existence of the 2 diseases increases the risk of liver-related adverse outcomes and imposes a heavier burden on extrahepatic outcomes, representing a substantial public health issue. Effective assessment and management of T2DM combined with MASLD necessitate a multidisciplinary approach. The emergence of numerous RCTs has shed light on the treatment of T2DM combined with MASLD. This review uncovers the epidemiology of the intertwined T2DM and MASLD, offers insights into the evaluation of hepatic fibrosis in patients with T2DM, glucose monitoring in the MASLD population, and provides comprehensive co-management strategies for addressing both diseases.

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.

Letter: Severe underweight and sarcopenia in decompensated cirrhosis are associated with high FGF21 levels

This article is linked to Alkhouri et al papers. To view these articles, visit https://doi.org/10.1111/apt.17709 and https://doi.org/10.1111/apt.17907

Letter: Severe underweight and sarcopenia in decompensated cirrhosis are associated with high FGF21 levels-authors' reply

This article is linked to Alkhouri et al papers. To view these articles, visit https://doi.org/10.1111/apt.17709 and https://doi.org/10.1111/apt.17881