The FDA lifted a clinical hold and allowed Intellia to resume one of two Phase 3 trials testing its CRISPR-based therapy nexiguran ziclumeran (nex-z) for transthyretin amyloidosis (ATTR). The agency imposed safety-driven entry criteria and monitoring requirements following a prior serious liver-toxicity event that resulted in a patient death. Intellia and its partner Regeneron aligned with FDA conditions that exclude patients with specified liver issues and severe cardiac instability, and require enhanced liver-enzyme surveillance and steroid guidance. CRISPR editing here is a one-time in vivo gene-editing approach to knock down transthyretin production; regulators are focusing on off-target and systemic toxicity signals. Analysts called the measures modest and flagged that the unknown mechanism behind the liver event remains an unresolved clinical and regulatory risk.