Liver Drug Resmetirom Works Just as Well in Patients Already Taking GLP-1 Medications: Phase 3 Trial Results | Research

The takeaway

Resmetirom's efficacy in resolving fatty liver disease and improving fibrosis was not diminished by background GLP-1 receptor agonist therapy, and patients who also lost 5% or more body weight saw enhanced outcomes.

56.6% MASH Resolution
Resmetirom 100 mg patients who lost ≥5% body weight achieved MASH resolution at nearly double the rate of those with less weight loss (33.8%)

What the researchers found

In a secondary analysis of the MAESTRO-NASH phase 3 trial, resmetirom (80 or 100 mg) maintained its efficacy on histological and biomarker endpoints regardless of background GLP-1 RA or SGLT2i therapy. Rates of MASH resolution and fibrosis improvement were similar between patients on and off these diabetes medications. Notably, resmetirom 100 mg patients achieving ≥5% weight loss showed superior outcomes: MASH resolution 56.6% vs. 33.8%, fibrosis improvement 40.6% vs. 31.5%, MRI-PDFF reduction -69% vs. -46%, and liver stiffness reduction -4.6 kPa vs. -2.3 kPa at 52 weeks.

Why it matters

Many patients with fatty liver disease also have type 2 diabetes and are taking GLP-1 receptor agonists like semaglutide. This analysis confirms that resmetirom — the first FDA-approved drug specifically for MASH — can be safely combined with these peptide therapies without losing effectiveness. The finding that weight loss enhances resmetirom's benefits further supports combining it with weight-reducing GLP-1 drugs.

How the study worked

This was a pre-specified secondary analysis of MAESTRO-NASH, a randomized, double-blind, placebo-controlled, 54-month phase 3 trial (NCT03900429). Patients had biopsy-confirmed MASH with liver fibrosis. Week 52 histological endpoints (MASH resolution, fibrosis improvement) and biomarker endpoints (MRI-PDFF, liver stiffness) were analyzed by background diabetes therapy status (GLP-1 RA, SGLT2i) and weight loss (≥5% vs. <5%).

What this study cannot tell us

This is a secondary analysis, not a trial specifically designed to test the combination. Only 13-17% of participants were on GLP-1 RA or SGLT2i therapy, limiting statistical power for subgroup comparisons. Background GLP-1 RA therapy did not produce additional weight loss in this cohort, which may not reflect typical GLP-1 RA treatment effects. The 52-week timepoint may not capture longer-term outcomes.

How to read the evidence

This is a secondary analysis from a large, well-designed phase 3 randomized controlled trial (MAESTRO-NASH). While the primary trial achieved its endpoints with high-quality evidence, this subgroup analysis has smaller sample sizes and was not independently powered, moderating the certainty of these specific findings.

When this study was published

Published in 2025 based on the MAESTRO-NASH trial, this analysis reflects the most current evidence on combining resmetirom with GLP-1 receptor agonists for fatty liver disease.

The bigger picture

The treatment landscape for MASH is rapidly evolving with both resmetirom (a thyroid hormone receptor agonist) and GLP-1 receptor agonists showing benefits. This analysis suggests these two drug classes can work together, potentially establishing combination therapy as a treatment paradigm for patients with the common overlap of fatty liver disease and type 2 diabetes. The synergy with weight loss is particularly relevant as GLP-1 drugs are powerful weight-loss agents.

Questions still open

Would a trial specifically designed to test resmetirom plus semaglutide combination therapy show additive or synergistic liver benefits?
Why did background GLP-1 RA therapy not produce additional weight loss in this cohort — were doses suboptimal or patients already at plateau?
Could the weight loss enhancement effect mean that newer, more potent GLP-1 agonists would yield even better MASH outcomes with resmetirom?

Common questions

Can I take resmetirom if I'm already on a GLP-1 drug like semaglutide?

According to this phase 3 trial analysis, yes — resmetirom was equally effective at resolving MASH and improving liver fibrosis regardless of whether patients were on background GLP-1 receptor agonist therapy. The two drug classes appear to be compatible.

Does weight loss make resmetirom work better?

Yes. Patients who lost at least 5% of their body weight while taking resmetirom 100 mg had significantly better outcomes: 57% achieved MASH resolution compared to 34% of those who lost less weight, and improvements in fibrosis, liver fat, and liver stiffness were all enhanced.

Read the original research

Effects of Resmetirom on Metabolic-Dysfunction Associated Steatohepatitis in Patients With Weight Loss and/or Diabetes Taking Glucagon-Like Peptide-1 Receptor Agonists and Other Diabetes Therapies: A Secondary Analysis of the MAESTRO-NASH Trial.

Alimentary pharmacology & therapeutics, 62(11-12), 1089-1099

View on PubMed ↗Publisher’s paper ↗

Citation

Noureddin, Mazen; Rinella, Mary; Taub, Rebecca; Labriola, Dominic; Camacho, Raul C; Alkhouri, Naim; Loomba, Rohit; Bansal, Meena B. (2025). Effects of Resmetirom on Metabolic-Dysfunction Associated Steatohepatitis in Patients With Weight Loss and/or Diabetes Taking Glucagon-Like Peptide-1 Receptor Agonists and Other Diabetes Therapies: A Secondary Analysis of the MAESTRO-NASH Trial.. Alimentary pharmacology & therapeutics, 62(11-12), 1089-1099. https://doi.org/10.1111/apt.70382