Madrigal Pharmaceuticals announces publication of Phase 3 MAESTRO-NASH trial

Madrigal Pharmaceuticals announced the publication of the pivotal Phase 3 MAESTRO-NASH trial of resmetirom in the New England Journal of Medicine. NASH is a leading cause of liver-related mortality and an increasing burden on healthcare systems globally. Resmetirom received Breakthrough Therapy designation from the FDA and is under review to become the first medicine approved to treat patients with NASH with liver fibrosis. The FDA granted resmetirom Priority Review and assigned a Prescription Drug User Fee Act date of March 14, 2024, the target date by which FDA intends to complete its review. The MAESTRO-NASH trial evaluates resmetirom treatment vs. placebo in patients with NASH with significant fibrosis, a population at elevated risk of progressing to cirrhosis and other adverse liver outcomes. The study includes a 52-week biopsy assessment to support accelerated approval and an ongoing 54-month outcomes study designed to generate confirmatory data that, if positive, will help verify resmetirom’s clinical benefit and support full approval. Based on the results of the 52-week biopsy portion of the trial, MAESTRO-NASH is the only Phase 3 study in NASH to achieve both primary endpoints that FDA proposed as reasonably likely to predict clinical benefit: NASH resolution with no worsening of fibrosis and fibrosis reduction with no worsening of NAFLD activity score. Approximately 50% of patients treated with resmetirom 100 mg with biopsies at Week 52 showed either NASH resolution or fibrosis improvement. More than 80% of patients with biopsies at Week 52 had either fibrosis reversal or no progression of fibrosis. In addition to the two primary endpoints, multiple secondary endpoints were achieved in the MAESTRO-NASH study, including statistically significant reduction from baseline in liver enzymes. Reductions in atherogenic lipids and lipoproteins, fibrosis biomarkers and imaging tests were observed in resmetirom treatment arms as compared with placebo. MAESTRO-NASH also included many biomarker and imaging assessments that may be used in real world clinical practice to identify appropriate patients for treatment and monitor response to resmetirom, if approved. The incidence of serious adverse events was similar across the treatment groups, 10.9%, 12.7%, and 11.5% in 80 mg, 100 mg and placebo groups respectively. Transient diarrhea and nausea were more frequent with resmetirom at the beginning of therapy. No increase in the incidence of diarrhea and nausea was noted among resmetirom-treated patients relative to placebo-treated patients after the first few weeks of treatment. There was no incidence of drug-induced liver injury. There were no increases in bone fractures, or fracture risk score with resmetirom or increase in adverse events related to thyroid hormone effects outside the liver such as heart rate changes or sex hormone abnormalities.