Intellia Pauses Late-Stage CRISPR Trials After Severe Liver Injury Hospitalization

Intellia Therapeutics has paused two late-stage Phase 3 clinical trials of its CRISPR-based gene-editing therapy nexiguran ziclumeran (nex-z) for transthyretin amyloidosis after a patient experienced severe liver injury requiring hospitalization. The patient, a man in his 80s, showed life-threatening elevations in liver enzymes and bilirubin, raising concerns about potential liver toxicity linked to the therapy. This safety issue marks the second serious liver-related event reported by Intellia since May, leading to a sharp decline of over 40% in the company's stock and negatively impacting other CRISPR-focused biotech firms. Intellia's CEO emphasized patient safety and the company's intent to consult with regulators and experts to develop risk-mitigation strategies and resume trials when appropriate. However, analysts and industry observers express skepticism about Intellia's future prospects, noting that effective treatments for the targeted diseases already exist, which raises the bar for safety and efficacy. The pause underscores the challenges gene-editing therapies face in balancing innovative potential with patient safety and regulatory scrutiny.