Should laboratory monitoring be performed at the three‑month follow‑up after initiating Rezdiffra?

YES - Bloodwork at 3 Months is Recommended for Safety Monitoring

Yes, you should perform laboratory monitoring at the 3-month (Week 12) follow-up after initiating Rezdiffra, but this assessment is specifically for safety and tolerability, NOT for efficacy evaluation. 111

Purpose of 3-Month Laboratory Assessment

The 3-month timepoint serves a critical but limited purpose:

• Primary goal: Exclude drug-induced liver injury (DILI) and confirm absence of concomitant liver disease 11
• Not for efficacy: Changes in ALT and other markers at 12 weeks do not accurately reflect treatment response and should not be used to judge whether the medication is working 111

What to Monitor at 3 Months

Based on the FDA label and expert guidelines, you should check:

Liver Function Tests

• ALT and AST: Mean elevations typically occur in the first 4 weeks (less than 1.5 times baseline), returning to baseline around 8 weeks 22
• Watch for: ALT or AST >3x ULN (occurred in 11-13% for ALT, 9-12% for AST in trials) 22
• Critical threshold: ALT or AST >5x ULN (occurred in only 2-4% of patients) 22

Clinical Assessment

• Tolerability: Assess for debilitating gastrointestinal symptoms (diarrhea, nausea, vomiting) that typically begin early in treatment 22
• Hypersensitivity: Monitor for urticaria, rash, or other allergic reactions 22

Critical Pitfall to Avoid

Do NOT make treatment decisions based on 3-month laboratory results. Changes in NITs (non-invasive tests) at 3 months were not reliably predictive of treatment response in the MAESTRO-NASH trial 11. Medical providers should reserve judgment on efficacy until 12 months 111.

Complete Monitoring Timeline

The expert panel recommends a structured 3-period assessment:

1. Week 12 (3 months): Safety and tolerability assessment only
2. 6 months: Disease monitoring with aminotransferases; VCTE or PDFF may suggest early response but absence of response is inadequate to assess treatment 11
3. 12 months and annually: Full efficacy monitoring with ALT, imaging (MRI-PDFF or VCTE), and liver stiffness measurement 111