Current and Future Therapeutic Regimens for Non-alcoholic Fatty Liver Disease (NAFLD) and Non-alcoholic Steatohepatitis (NASH)

NASH/NAFLD is rapidly becoming one of top causes of cirrhosis, hepatocellular carcinoma and indication for liver transplantation. Except for life style modification through diet and exercise, there are currently no other approved treatments for NASH/NAFLD. Although weight loss can be effective, it is hard to achieve and sustain. In contrast, bariatric surgery can improve metabolic conditions associated with NAFLD and has been shown to improve liver histology. In order to have approved regimens for treatment of NASH/NAFLD, a number of issues that must be addressed. First, all stakeholders must agree on the most appropriate clinical trial endpoints for NASH. Currently, resolution of NASH (without worsening fibrosis) or reduction of fibrosis stage (without worsening NASH) are the accepted endpoints by the regulatory authorities. It is important to recognize the prognostic implication of histologic features of NASH. In this context, although histologic NASH has been associated with advanced stage of fibrosis, it is not an independent predictor of long term mortality. In contrast, there is significant data to suggest that stage of fibrosis is the only robust and independent predictor of liver-related mortality. In addition to the primary endpoints, a number of important secondary endpoints, including non-invasive biomarkers, long term outcomes, and patient reported outcomes, must be considered. In 2017, a few phase 3 clinical trials for treatment of NASH are in progress. Additionally, a number of phase 2a and 2b clinical trials targeting different pathogenic pathways in NASH enriches the pipeline of emerging therapies.