Clinical research
Being tested in people in registered clinical trials. Being in trials is not evidence that a treatment works or is safe.
What this trial is testing
A large late-stage trial testing whether a single infusion of a CRISPR treatment, which switches off a gene in the liver, helps people whose hearts are being damaged by amyloid deposits. In 2025 a participant died of liver failure after dosing; the trial was paused and placed on hold by the FDA, and the hold was later lifted.
A global Phase 3 study of nexiguran ziclumeran, a lipid-nanoparticle CRISPR-Cas9 therapy knocking out hepatic TTR, in participants with ATTR cardiomyopathy. Following a serious hepatic adverse event and death in a participant in his early eighties, Intellia voluntarily paused dosing and screening; the FDA imposed a clinical hold, which was subsequently lifted for this study.
Sources
- Intellia Therapeutics · 2025
Intellia provides update on MAGNITUDE clinical trials ↗ - Intellia Therapeutics · 2025
Intellia announces FDA lift of clinical hold on MAGNITUDE Phase 3 clinical trial in ATTR-CM ↗
What a trial result does and does not mean
Early-phase results come from small numbers of participants and short follow-up. They can change with more people and more time, and a trial that is recruiting, active or even completed has not established that a treatment works. Enrolment criteria are strict; eligibility is decided by the trial site, never by a website.