The U.S. Food and Drug Administration has lifted a clinical hold on Intellia Therapeutics’ Magnitude‑2 Phase 3 trial of its CRISPR/Cas9 therapy nexiguran ziclumeran (nex‑z) for transthyretin amyloidosis with polyneuropathy (ATTR‑PN), allowing that trial to restart while a sister study for the cardiomyopathy indication remains paused. The move follows agency review after a serious hepatic adverse event in the related cardiomyopathy study. Intellia confirmed discussions with the FDA continue around the Magnitude trial (cardiomyopathy) and that Magnitude‑2’s resumption is contingent on agreed additional safeguards. The company said Magnitude‑2 restart should help preserve timelines for the ATTR‑PN program while addressing safety signals from the broader development program. Analysts and investors reacted positively to the partial lift, citing reduced near‑term regulatory uncertainty for the polyneuropathy indication. The FDA’s step underscores the agency’s case‑by‑case approach to complex in vivo gene‑editing programs and the need for enhanced monitoring when severe, idiosyncratic toxicities emerge. Regulators, developers and trial sites will now need to implement the agreed safety measures and monitoring protocols before patient dosing resumes in Magnitude‑2.