Jayasekera, Channa R

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, metabolic dysfunction-associated steatohepatitis (MASH), are among the most prevalent causes of chronic liver disease worldwide, closely linked to the global rise in overweight and obesity, type 2 diabetes, and metabolic syndrome. Until recently, treatment options were limited to lifestyle interventions, with no approved pharmacologic therapies. Resmetirom, a liver-directed, selective thyroid hormone receptor beta (THR-β) agonist, is a promising disease-modifying agent that targets hepatic lipid metabolism, inflammation, and fibrosis. Clinical trials, including the pivotal phase 3 MAESTRO-NASH and MAESTRO-NAFLD-1 trials, have demonstrated significant improvements in liver fat reduction, lipid profiles, histological endpoints, and health-related quality of life, with a favorable safety profile. In March 2024, the FDA granted accelerated approval of resmetirom for adults with MASH and moderate-to-advanced fibrosis, marking a significant milestone in MASLD treatment. This review discusses the mechanistic rationale, preclinical data, and pivotal clinical trial outcomes supporting resmetirom’s role in MASLD/MASH management, while outlining ongoing research needs, including long-term safety, pediatric evaluation, and biomarker development for optimized patient selection.