Resmetirom Monitoring Protocol: Elastography Timeline for Clinicians
Practical monitoring protocol for clinicians prescribing resmetirom (Rezdiffra) — baseline assessment, elastography intervals, and tracking treatment response.
Resmetirom (Rezdiffra) is the first medication approved specifically for the treatment of MASH with significant fibrosis. FDA approval came in March 2024; EMA approval followed in August 2025. TGA submission in Australia is anticipated. This article outlines a practical monitoring protocol for clinicians prescribing or supervising patients on resmetirom in eligible jurisdictions, and is intended as a framework — not a substitute for the prescribing information.
Baseline assessment before initiation
MAESTRO-NASH eligibility criteria, which underpin current prescribing, include biopsy-confirmed MASH with F2–F3 fibrosis, or non-invasive equivalents including significant elastography stiffness (typically kPa ≥8.5–9.0 in MASLD context) plus elevated CAP/UAP, supportive imaging, and metabolic risk factors.
Baseline workup should include: full liver function tests including GGT, FIB-4, lipid panel, HbA1c, weight/BMI, blood pressure, and elastography (kPa + CAP or UAP). Confirm hepatitis B and C status before starting. Establish a baseline thyroid function panel — resmetirom is a selective THR-β agonist.
Treatment monitoring intervals
Months 1, 3, and 6: liver function tests and clinical review. ALT and AST commonly fall in the first 3 months — modest reductions are expected and not concerning. Significant AST/ALT elevations above baseline warrant investigation per prescribing guidance.
Month 12: repeat elastography (kPa + CAP/UAP), full liver function tests, lipid panel, weight, blood pressure, and clinical assessment. The MAESTRO-NASH trial showed mean reductions of approximately 6.7 kPa from baseline in fibrosis responders over 2 years, with meaningful kPa reductions typically detectable from 12 months onward.
Baveno VII criteria suggest a change of ≥5 kPa between elastography measurements is clinically meaningful — useful as a response threshold when discussing treatment effect with patients.
What constitutes a clinical response
There is no single agreed non-invasive response definition for MASH treatment yet, but reasonable composite criteria include: kPa reduction of ≥5 kPa or ≥25% from baseline, CAP/UAP reduction reflecting meaningful steatosis improvement (typically a one-grade S-stage drop), normalisation or stable improvement of ALT/AST, and stable or improving metabolic markers.
Non-responders at 24 months should trigger a treatment review — including assessment of adherence, metabolic context, and consideration of whether biopsy reassessment is appropriate.
Practical workflow notes
Booking 12-monthly elastography for resmetirom patients is a high-yield workflow integration for any clinic with in-house or partnered elastography capacity. Consider a recall pathway alongside HbA1c review for diabetic patients.
Elastography reports for resmetirom monitoring should include both kPa and CAP/UAP, plus the IQR ratio for reliability assessment. Repeat measurements on the same device (and ideally same operator) reduce between-scan variability.
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