Two of Intellia Therapeutics’ clinical trials that had been on hold since October 2025 have now been released by the FDA. The Agency initially issued the holds due to reports of severe liver toxicity leading to death.
Magnitude was originally known as NTLA-2001. It is a one-time gene-editing therapy developed to treat amyloidosis (pronounced am-uh-loi-DO-sis). The protein, known as amyloid, accumulates and affects major organs.
The trials, Magnitude and Magnitude-2 were halted when a patient was reported to have raised levels of liver enzymes eventually leading to the patient’s death.
Magnitude, Phase 3 Trial
The FDA has now lifted its hold on the Magnitude phase 3 trial investigating nexiguran ziclumeran (nex-z) in patients with ATTR-CM.
The protein becomes misshapen causing clumps to occur in the gene. These clumps damage the heart and various other organs.
The FDA Issues Caution
Each release contains caveats by Intellia. Patients with liver or heart issues will be excluded from the Magnitude trials.
Additional safety issues were announced, such as the degree of monitoring liver enzymes and offering guidance on steroid therapy to patients with side effects that are potentially dangerous.
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Rose Duesterwald July 23, 2026
