FDA Approves Resmetirom (Rezdiffra) as First Oral Treatment for NASH Liver Fibrosis: Phase 3 Results 2026

Medically reviewed | Published: | Evidence level: 1A
Resmetirom (Rezdiffra, Madrigal Pharmaceuticals) received FDA accelerated approval in March 2024 as the first drug approved for NASH with moderate to advanced fibrosis (F2-F3). The MAESTRO-NASH phase 3 trial enrolled 966 patients and showed significant fibrosis improvement compared to placebo.
📅 Published:
Reviewed by iMedic Medical Editorial Team
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Quick Facts

First-in-class
First FDA-approved NASH drug
Mechanism
THR-β agonist
Trial
MAESTRO-NASH phase 3

What Is Resmetirom and How Does It Treat NASH?

Quick answer: Quick answer: Resmetirom is a liver-targeted thyroid hormone receptor beta agonist that reduces liver fat, inflammation, and fibrosis by selectively activating metabolic pathways in hepatocytes.

Resmetirom (Rezdiffra, Madrigal Pharmaceuticals) received FDA accelerated approval in March 2024 as the first drug approved for NASH with moderate to advanced fibrosis (F2-F3). The MAESTRO-NASH phase 3 trial enrolled 966 patients and showed significant fibrosis improvement compared to placebo.

The drug selectively activates thyroid hormone receptor beta, predominantly expressed in the liver, enhancing mitochondrial fatty acid β-oxidation and reducing hepatic triglyceride content. Additionally, NASH resolution was achieved in a significant proportion of patients.

What Are the Cardiovascular Benefits Beyond Liver Disease?

Quick answer: Quick answer: Resmetirom significantly reduces LDL cholesterol, apolipoprotein B, and triglycerides, providing cardiovascular benefits for NASH patients with elevated heart disease risk.

NASH patients face increased cardiovascular event risk. Resmetirom demonstrated significant reductions in LDL cholesterol, apolipoprotein B, lipoprotein(a), and triglycerides — reductions comparable to moderate-intensity statin therapy.

The AASLD has recognized resmetirom as an important advance in NASH pharmacotherapy, particularly for patients with concomitant dyslipidemia.

Frequently Asked Questions

Resmetirom is taken as a once-daily oral tablet (100 mg) with food. The most common side effects include diarrhea and nausea.

Resmetirom is approved for adults with NASH confirmed by liver biopsy showing moderate to advanced fibrosis (stage F2 or F3). Patients with cirrhosis (F4) were excluded from trials.

Yes, resmetirom can be used alongside statins with additive LDL-lowering effects and no increased risk of liver toxicity based on trial data.

References

  1. Harrison SA et al. Resmetirom (MGL-3196) for the treatment of non-alcoholic steatohepatitis: MAESTRO-NASH randomised, double-blind, placebo-controlled phase 3 trial. Lancet. 2024;403(10432):1167-1177.
  2. U.S. Food and Drug Administration. FDA Approves First Treatment for Patients with Liver Scarring Due to Fatty Liver Disease. FDA News Release, March 14, 2024.
  3. Madrigal Pharmaceuticals. Rezdiffra (resmetirom) Prescribing Information. 2024.