Is resmetirom indicated for a patient with non‑alcoholic fatty liver disease and elevated alanine aminotransferase (ALT)?

Resmetirom for Fatty Liver with Elevated ALT

Yes, resmetirom can be used in patients with fatty liver and elevated ALT, but only if they have confirmed MASH (metabolic dysfunction-associated steatohepatitis) with moderate to advanced fibrosis (F2-F3 stage) and do not have cirrhosis. 1, 2

Key Requirements Before Starting Resmetirom

1. Confirm the Diagnosis

You must first establish that the patient has MASH, not just simple steatosis:

• Exclude other liver diseases: Rule out autoimmune hepatitis (check ANA, anti-smooth muscle antibodies), viral hepatitis, iron overload, and significant alcohol use (consider phosphatidylethanol testing if PeTH >200, do not treat) 1
• Confirm metabolic dysfunction: The patient should have features of metabolic syndrome (obesity, diabetes, dyslipidemia)

2. Document Appropriate Fibrosis Stage (F2-F3)

The FDA approval specifically requires moderate to advanced fibrosis without cirrhosis. You can establish this using:

Non-invasive tests (NITs) - preferred approach:

• Liver stiffness by VCTE (FibroScan): 10-20 kPa suggests F2-F3 1
• MR elastography (MRE): 3.1-4.4 kPa indicates F2-F3 3
• Use concordant tests: Two blood-based tests or liver stiffness measurements should agree to reduce false positives 1
• Enhanced Liver Fibrosis (ELF): If using ELF alone, values between 9.8-11.3 suggest F2-F3, but require confirmation with another NIT 1

Liver biopsy (if available):

• If biopsy within 12 months shows F2-F3 fibrosis, you can proceed regardless of NIT values, provided no clinical/imaging evidence of portal hypertension 1

3. Exclude Cirrhosis - Critical Safety Step

Do NOT use resmetirom if any of the following are present: 1

• VCTE >20 kPa or MRE >5 kPa
• Platelets <140,000/µL (without alternative explanation)
• ELF >11.3
• Clinical signs of portal hypertension (ascites, varices, hepatic encephalopathy)
• Hepatic nodularity on imaging
• History of F4 fibrosis on prior biopsy

Regarding Elevated ALT Specifically

Elevated ALT is actually expected and appropriate in MASH patients being considered for resmetirom. Here's what you need to know:

Early ALT Changes During Treatment

• Expect transient ALT increases in the first 4 weeks, particularly in patients on statins 1
• Mean increases are typically <1.5x baseline
• These elevations usually normalize by week 8 without stopping the drug 1
• Do not make discontinuation decisions before week 12 unless there are signs of hepatotoxicity 1

Monitoring Protocol

• Check liver enzymes at 12 weeks to assess for true hepatotoxicity 1
• Educate patients about hepatotoxicity symptoms: fatigue, nausea, vomiting, right upper quadrant pain, jaundice, fever, rash 1, 2
• Stop resmetirom immediately if persistent and significant liver enzyme elevation occurs with symptoms 1

ALT as a Response Marker

• ALT improvement (when accompanied by 30% reduction in MRI-PDFF) can indicate treatment response 1
• However, histologic improvements may occur without corresponding ALT changes, so don't rely on ALT alone to assess efficacy 1

Dosing and Administration

Weight-based dosing: 1

• 80 mg daily if body weight <100 kg
• 100 mg daily if body weight ≥100 kg
• Take once daily with or without food 2

Important Drug Interactions

Contraindicated combinations: 1, 2

• Gemfibrozil (strong CYP2C8 inhibitor)
• Cyclosporine (OATP1B1/1B3 substrate)

Statin dose adjustments required: 1

• Rosuvastatin and simvastatin: limit to 20 mg/day
• Pravastatin and atorvastatin: limit to 40 mg/day
• This is not problematic as resmetirom reduces LDL-cholesterol by 14-20% 1

Use with caution:

• Clopidogrel (moderate CYP2C8 inhibitor) - requires dose reduction and closer monitoring 1, 2

Common Pitfalls to Avoid

1. Don't treat patients with F0-F1 fibrosis - they are excluded from the FDA indication 1
2. Don't miss occult cirrhosis - use multiple NITs to avoid treating F4 patients 1
3. Don't stop treatment prematurely for early ALT elevation - wait until week 12 unless symptomatic 1
4. Don't assess treatment response before 12 months - earlier assessments may be misleading 1
5. Don't forget to screen for autoimmune hepatitis - this can cause elevated liver enzymes during trials and mimic treatment failure 1

Expected Side Effects

Most common (generally mild-moderate): 1, 2

• Diarrhea (median onset 6-17 days, duration ~20 days)
• Nausea (median onset 5-28 days, duration ~26-28 days)
• Constipation, abdominal pain, vomiting
• Patient education about these effects reduces unnecessary discontinuation 1

Serious concerns to monitor:

• Hepatotoxicity (check at 12 weeks) 1
• Gallbladder problems (gallstones, cholecystitis, pancreatitis from gallstones) 2

Bottom Line Algorithm

START resmetirom if:

1. Confirmed MASLD/MASH (other causes excluded)
2. Fibrosis stage F2-F3 by NITs or biopsy
3. No cirrhosis or portal hypertension
4. No contraindicated medications
5. Elevated ALT is present (this is typical and expected)

MONITOR:

• Liver enzymes at 12 weeks for safety
• Treatment response at 12 months using MRI-PDFF (30% reduction) or other NITs 1

STOP if:

• Persistent significant liver enzyme elevation with symptoms
• Development of cirrhosis or portal hypertension
• Intolerable side effects

The elevated ALT in your patient is not a contraindication—it's actually part of the expected disease profile for MASH patients who are appropriate candidates for resmetirom.