A short report on NGM282/aldafermin for the treatment of nonalcoholic steatohepatitis (NASH)

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

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

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.

Gut-liver axis in the progression of nonalcoholic fatty liver disease: From the microbial derivatives-centered perspective

Nonalcoholic fatty liver disease (NAFLD) is one of the world's most common chronic liver diseases. However, its pathogenesis remains unclear. With the deepening of research, NAFLD is considered a metabolic syndrome associated with the environment, heredity, and metabolic disorders. Recently, the close relationship between the intestinal microbiome and NAFLD has been discovered, and the theory of the "gut-liver axis" has been proposed. In short, the gut bacteria directly reach the liver via the portal vein through the damaged intestinal wall or indirectly participate in the development of NAFLD through signaling pathways mediated by their components and metabolites. This review focuses on the roles of microbiota-derived lipopolysaccharide, DNA, peptidoglycan, bile acids, short-chain fatty acids, endogenous ethanol, choline and its metabolites, indole and its derivatives, and bilirubin and its metabolites in the progression of NAFLD, which may provide significative insights into the pathogenesis, diagnosis, and treatment for this highly prevalent liver disease.

Fibroblast Growth Factors for Nonalcoholic Fatty Liver Disease: Opportunities and Challenges

Nonalcoholic fatty liver disease (NAFLD), a chronic condition associated with metabolic dysfunction and obesity, has reached epidemic proportions worldwide. Although early NAFLD can be treated with lifestyle changes, the treatment of advanced liver pathology, such as nonalcoholic steatohepatitis (NASH), remains a challenge. There are currently no FDA-approved drugs for NAFLD. Fibroblast growth factors (FGFs) play essential roles in lipid and carbohydrate metabolism and have recently emerged as promising therapeutic agents for metabolic diseases. Among them, endocrine members (FGF19 and FGF21) and classical members (FGF1 and FGF4) are key regulators of energy metabolism. FGF-based therapies have shown therapeutic benefits in patients with NAFLD, and substantial progress has recently been made in clinical trials. These FGF analogs are effective in alleviating steatosis, liver inflammation, and fibrosis. In this review, we describe the biology of four metabolism-related FGFs (FGF19, FGF21, FGF1, and FGF4) and their basic action mechanisms, and then summarize recent advances in the biopharmaceutical development of FGF-based therapies for patients with NAFLD.

Fibroblast growth factor 21 and dietary interventions: what we know and what we need to know next

Dietary interventions include the change of dietary styles, such as fasting and dietary or nutrient restrictions; or the addition of plant-derived compounds (such as polyphenols known as curcumin, resveratrol, or anthocyanin, or other nutraceuticals) into the diet. During the past a few decades, large number of studies have demonstrated therapeutic activities of these dietary interventions on metabolic and other diseases in human subjects or various animal models. Mechanisms underlying those versatile therapeutic activities, however, remain largely unclear. Interestingly, recent studies have shown that fibroblast growth factor 21 (FGF21), a liver-derived hormone or hepatokine, mediates metabolic beneficial effects of certain dietary polyphenols as well as protein restriction. Here I have briefly summarized functions of FGF21, highlighted related dietary interventions, and presented literature discussions on role of FGF21 in mediating function of dietary polyphenol intervention and protein restriction. This is followed by presenting my perspective view, with the involvement of gut microbiota. It is anticipated that further breakthroughs in this field in the near future will facilitate conceptual merge of classical medicine and modern medicine.

Pathogenesis and Therapeutic Strategies Related to Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), one of the most common types of chronic liver disease, is strongly correlated with obesity, insulin resistance, metabolic syndrome, and genetic components. The pathological progression of NAFLD, consisting of non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and liver cirrhosis, is characterized by a broad spectrum of clinical phenotypes. Although patients with mild NAFL are considered to show no obvious clinical symptoms, patients with long-term NAFL may culminate in NASH and further liver fibrosis. Even though various drugs are able to improve NAFLD, there are no FDA-approved medications that directly treat NAFLD. In this paper, the pathogenesis of NAFLD, the potential therapeutic targets, and their underlying mechanisms of action were reviewed.

Molecular Basis of Bile Acid-FXR-FGF15/19 Signaling Axis

Bile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver. The FXR/RXRα heterodimer also exists in the distal ileum and regulates production of fibroblast growth factor (FGF) 15/FGF19, a hormone traveling via the enterohepatic circulation that activates hepatic FGF receptor 4 (FGFR4)-β-klotho receptor complex and regulates gene expression involved in cholesterol, BA, and lipid metabolism, as well as those regulating cell proliferation. Agonists for FXR and analogs for FGF15/19 are currently recognized as a promising therapeutic target for metabolic syndrome and cholestatic diseases.