Intellia Pauses Nex‑z Trials, Reassesses Pipeline

On Oct. 27, Intellia Therapeutics paused patient dosing and screening in its Phase 3 MAGNITUDE and MAGNITUDE‑2 trials of Nex‑z after a patient dosed on Sept. 30 developed Grade 4 liver transaminase elevations, increased total bilirubin and was hospitalized. The company said it is investigating the event, consulting external experts and regulators, assessing risk‑mitigation steps and prioritizing the patient’s care, and that the finding does not currently apply to its other programs. MAGNITUDE has enrolled more than 650 ATTR‑CM patients, MAGNITUDE‑2 has 47 ATTR‑PN patients, and Intellia estimates more than 450 patients have been dosed across both trials. The safety pause triggered a sharp market reaction, with Intellia shares plunging roughly 40–46% on heavy volume. Separately, Intellia said early Phase 1/2 data for NTLA‑3001 (alpha‑1 antitrypsin deficiency) showed successful in‑vivo editing but lower‑than‑expected efficacy, prompting a strategic reassessment and reprioritization of programs. Management said it remains committed to advancing its CRISPR pipeline, will provide further updates on timelines and cost actions, and is engaging stakeholders on a path to resume enrollment as appropriate.