Therapeutic targets in liver fibrosis

Detailed analysis of the cellular and molecular mechanisms that mediate liver fibrosis has provided a framework for therapeutic approaches to prevent, slow down, or even reverse fibrosis and cirrhosis. A pivotal event in the development of liver fibrosis is the activation of quiescent hepatic stellate cells (HSCs) to scar-forming myofibroblast-like cells. Consequently, HSCs and the factors that regulate HSC activation, proliferation, and function represent important antifibrotic targets. Drugs currently licensed in the US and Europe for other indications target HSC-related components of the fibrotic cascade. Their deployment in the near future looks likely. Ultimately, treatment strategies for liver fibrosis may vary on an individual basis according to etiology, risk of fibrosis progression, and the prevailing pathogenic milieu, meaning that a multiagent approach could be required. The field continues to develop rapidly and starts to identify exciting potential targets in proof-of-concept preclinical studies. Despite this, no antifibrotics are currently licensed for use in humans. With epidemiological predictions for the future prevalence of viral, obesity-related, and alcohol-related cirrhosis painting an increasingly gloomy picture, and a shortfall in donors for liver transplantation, the clinical urgency for new therapies is high. There is growing interest from stakeholders keen to exploit the market potential for antifibrotics. However, the design of future trials for agents in the developmental pipeline will depend on strategies that enable equal patient stratification, techniques to reliably monitor changes in fibrosis over time, and the definition of clinically meaningful end points.