50 Percent MRI-PDFF Reduction Emerges as Key Predictor of Fibrosis Regression in MASH

Background: MRI-PDFF (proton-density-fat fraction) is a validated noninvasive biomarker of liver fat used in metabolic dysfunction–associated steatohepatitis (MASH) trials. A ≥30% reduction is associated with MASH resolution, but its ability to predict fibrosis regression is uncertain. A ≥50% reduction, or “super-response,” may better reflect meaningful histologic change. Objective: To evaluate whether MRI-PDFF super-response predicts fibrosis regression and MASH resolution better than standard MRI-PDFF response. Methods: The study involved secondary analysis of a randomized, placebo-controlled trial including 163 adults with biopsy-confirmed MASH and stage 2 or 3 fibrosis. The median age was 56 years, and the body mass index was 36.5 kg/m 2 . Paired MRI-PDFF and liver biopsy were performed at baseline and 24 weeks. Primary outcomes were fibrosis improvement without worsening MASH and MASH resolution without worsening fibrosis. Results: MRI-PDFF response was a more...