The US FDA has opened an investigation into Novartis’ Zolgensma following reports of cancer in treated patients. The agency said it is assessing a “serious risk” associated with the spinal muscular atrophy gene therapy, after Novartis’ earlier disclosure. Zolgensma delivers a SMN1 gene via AAV-based vector. FDA scrutiny centers on long-term safety signals that can emerge as treated cohorts mature and follow-up continues. The investigation underscores how even established gene therapies with regulatory history can face renewed safety review when new clinical cases are reported, potentially affecting label language and post-marketing requirements.