FDA releases hold on second of Intellia’s ATTR-CM gene therapy trials

The US Food and Drug Administration (FDA) has released the clinical hold on a second trial evaluating Intellia Therapeutics’ transthyretin amyloidosis with cardiomyopathy (ATTR-CM) gene therapy.

The agency placed the MAGNITUDE and MAGNITUDE 2 trials (NCT06128629; NCT06672237) on hold in October 2025 after a case of Grade 4 liver transaminases and increased total bilirubin in a patient dosed with Intellia’s gene therapy nexiguran ziclumeran (nex-z), being developed in partnership with Regeneron.