End-points for drug treatment in NASH

Non-alcoholic steatohepatitis (NASH) is an increasingly common cause of cirrhosis, hepatocellular carcinoma, and liver-related death (LRD). Consequently, there is a critical need for effective drug therapy that improves clinically relevant end-points. Hepatic steatosis assessed by magnetic resonance imaging-proton density fat fraction is increasingly used in the early phase trials examining drugs with anti-steatotic effects. However, the prognostic significance of a reduction in steatosis is unknown, and thus, phase 3 trials require a histological end-point of NASH resolution without fibrosis progression. Nonetheless, it is not clear whether this end-point which requires a liver biopsy reflects a better prognosis. Thus, conditional drug approval currently requires long-term follow-up to demonstrate reduction in 'harder' end-points of cirrhosis, liver transplantation, and LRD. Currently, there is an essential need to develop accurate non-invasive markers that are dynamic to drug-induced changes in underlying disease severity and prognosis to utilize as surrogate end-points for clinical trials in NASH.