Intellia Therapeutics Pauses Clinical Trials After Patient Safety Incident

CAMBRIDGE, Mass., Oct. 27, 2025 (GLOBE NEWSWIRE) — Intellia Therapeutics, Inc. (NASDAQ: NTLA) has temporarily paused patient dosing and screening in its Phase 3 MAGNITUDE and MAGNITUDE-2 clinical trials for the investigational treatment, nexiguran ziclumeran (nex-z). This decision follows a serious safety event reported on October 24, 2025, involving a patient who developed severe liver enzyme elevations.

The incident occurred on September 30, 2025, when a patient enrolled in the MAGNITUDE trial was dosed with nex-z. The patient subsequently exhibited Grade 4 liver transaminase elevations and increased bilirubin levels, leading to hospitalization. Intellia is actively engaging with regulatory bodies and consulting with medical experts to understand the implications of this event.

As of October 27, 2025, there are more than 650 patients enrolled in the MAGNITUDE trial for transthyretin amyloidosis with cardiomyopathy (ATTR-CM) and 47 in the MAGNITUDE-2 trial for ATTR-PN. The company estimates that over 450 patients have already been dosed with nex-z in these trials.

“In line with our commitment to patient safety, we have taken immediate action to temporarily pause enrollment in MAGNITUDE and MAGNITUDE-2 as we investigate this recent event,” said John Leonard, M.D., President and CEO of Intellia Therapeutics. “Ensuring the health of our patients remains our top priority.”

A conference call and webcast have been scheduled for 8:30 a.m. ET on October 27, 2025, to discuss these developments and answer questions from stakeholders.