Resmetirom: First-Ever FDA-Approved Drug Significantly Improves MASH and Liver Fibrosis

Metabolic Dysfunction-Associated Steatohepatitis (MASH), formerly known as Non-alcoholic Steatohepatitis (NASH), is a severe form of fatty liver disease characterized by inflammation, liver cell damage, and fibrosis, which can progress to cirrhosis, liver failure, and even hepatocellular carcinoma. Despite its growing prevalence and significant health burden, there have been no FDA-approved pharmacological treatments specifically for MASH, leaving a critical unmet medical need. This study provides an update on the pivotal Phase 3 clinical trial data that led to the first-ever regulatory approval of resmetirom for MASH.

Both doses of resmetirom demonstrated statistically significant improvements in key histological endpoints compared to placebo. The 100 mg daily dose was particularly effective. MASH resolution without worsening of fibrosis was achieved in 25.9% of patients receiving resmetirom 100 mg, significantly higher than 9.6% in the placebo group (p<0.0001). Fibrosis improvement by at least one stage without worsening of MASH was observed in 24.2% of patients on resmetirom 100 mg, compared to 14.2% in the placebo group (p<0.0001). Additionally, liver fat content, measured by MRI-PDFF, showed a substantial 42.9% reduction from baseline in the 100 mg group, versus only 2.0% in the placebo group (p<0.0001). The drug was generally well-tolerated, with diarrhea being the most common adverse event, occurring in 12.1% of the 100 mg group versus 5.6% of placebo.