The FDA imposed a clinical hold on two Phase 3 studies of Intellia’s CRISPR gene‑editing therapy nexiguran ziclumeran (nex‑z) following reports of liver complications. The hold covers trials in transthyretin amyloidosis and pauses enrollment and dosing while regulators review safety data. Intellia’s programs employ in vivo CRISPR to inactivate the disease‑causing gene; the agency’s action underscores intensified scrutiny of systemic gene‑editing approaches after safety signals emerge. The hold will delay Intellia’s development timelines and could prompt protocol amendments or additional monitoring requirements. Developers of in vivo gene editors and investors now face a higher bar for demonstrating organ‑specific safety before late‑stage approval pathways are cleared.