Reporter’s Notebook: Is Intellia’s Patient Death the Nail in the Coffin for Cas9?

Reporter’s Notebook: Is Intellia’s Patient Death the Nail in the Coffin for Cas9?

I’ve been poring over the news around Intellia Therapeutics’ NTLA-2001, an in vivo CRISPR-Cas9 therapy to inactivate the TTR gene in two sets of transthyretin amyloidosis patients. On October 27, 2025, Intellia reported that an 80-year-old trial participant treated with NTLA-2001, also known as nexiguran ziclumeran (nex-z), had Grade 4 liver transaminases and increased total bilirubin, requiring hospitalization. The FDA placed a clinical hold on…