Intellia Therapeutics Halts MAGNITUDE Trials After Adverse Event Report

Intellia Therapeutics, a prominent gene editing company, has announced a temporary halt to patient dosing and screening in its MAGNITUDE clinical trials. This decision follows a report of a serious adverse event involving a patient who experienced significant liver issues after receiving their treatment, known as nex-z.

Details of the MAGNITUDE Trials Halt

On October 27, 2025, Intellia shared that the pause affects both MAGNITUDE and MAGNITUDE-2 trials. These studies are investigating nex-z for transthyretin amyloidosis-related conditions:

• MAGNITUDE: Focuses on patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM).
• MAGNITUDE-2: Targets polyneuropathy associated with transthyretin amyloidosis (ATTR-PN).

The patient in question was treated on September 30, 2025, and subsequently hospitalized due to Grade 4 liver transaminases and elevated bilirubin levels. This incident met the established pausing criteria outlined in the trial’s protocol.

Ongoing Patient Care and Future Considerations

The affected patient is under careful medical monitoring and intervention. In response to this event, Intellia is collaborating with experts and regulatory bodies to explore strategies to mitigate risks and possibly resume trials in a timely manner.

Intellia’s President and CEO, Dr. John Leonard, emphasized the company’s commitment to patient safety and the importance of thorough investigation. “We are dedicated to ensuring the health of our patients,” he stated.

Current Enrollment Statistics

As of now, the enrollment figures for the trials are as follows:

• MAGNITUDE: Over 650 patients enrolled with ATTR-CM.
• MAGNITUDE-2: 47 patients enrolled with ATTR-PN.

More than 450 of these individuals are estimated to have received nex-z treatment.

About Nex-z and Its Potential

Nex-z, based on CRISPR/Cas9 gene editing technology, aims to be a first-of-its-kind treatment for ATTR-CM and ATTR-PN. It works by inactivating the TTR gene responsible for producing the transthyretin protein.

The drug has previously garnered Orphan Drug and RMAT Designation from the U.S. FDA, along with Orphan Drug Designation from the European Commission. Preliminary Phase 1 data indicated significant and long-lasting TTR reduction following treatment.

Next Steps and Communication

Intellia plans to host a conference call at 8:30 a.m. ET to provide further updates. Interested parties can join the discussion via the Events and Presentations section on Intellia’s website or by telephone.

For more information on Intellia Therapeutics, visit Emegypt.