BACKGROUND AND AIMS: Liver fibrosis is a key process in the progression of chronic liver diseases. However, there are currently no drugs specifically designed to treat liver fibrosis. Our Phase 2 trial of hydronidone for the treatment of chronic hepatitis B (CHB)-associated liver fibrosis showed that adding hydronidone to entecavir resulted in significant reversal of liver fibrosis. To further evaluate the efficacy of a 270 mg/day dose of hydronidone for treating liver fibrosis associated with CHB, we conducted this Phase 3 trial. METHODS: This is a 52-week, randomized (1:1), double-blind, placebo-controlled, multicenter, entecavir-based Phase 3 clinical study conducted at 44 study centers across China. Adult patients aged 18 to 65 years with significant liver fibrosis (defined as an Ishak score ≥ 3 on liver biopsy) associated with CHB were included. RESULTS: The primary endpoint of the trial is to demonstrate the efficacy of fibrosis reversal, defined as a decrease in the Ishak stage score of liver fibrosis by ≥1 after 52 weeks of treatment, compared to baseline. CONCLUSIONS: The results of this trial are expected to further support the antifibrotic indication for this novel drug.