Drug Pipeline for MASLD: What Can Be Learned from the Successful Story of Resmetirom

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, metabolic dysfunction-associated steatohepatitis (MASH), represent a growing global health problem linked to obesity, insulin resistance, and dyslipidemia. MASLD often leads to fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, therapeutic options are limited, emphasizing the need for novel, targeted pharmacological interventions. Resmetirom, a selective thyroid hormone receptor beta (THR-β) agonist, offers a promising approach by specifically enhancing hepatic metabolism while minimizing systemic effects. Clinical trials have demonstrated its capacity to reduce hepatic triglyceride accumulation and improve lipid profiles. Early- and advanced-phase studies, including the MAESTRO program, highlight significant reductions in hepatic fat content and favorable impacts on noninvasive biomarkers of fibrosis with minimal side effects. This review highlights evidence from pivotal studies, explores resmetirom's mechanism of action, and compares its efficacy and safety with other emerging therapeutic agents. While resmetirom marks a breakthrough in non-cirrhotic MASH management, further long-term studies are essential to fully evaluate its clinical benefits and potential regulatory approval for broader use in MASLD and MASH.