The FDA has opened an investigation into a “serious risk” of cancer associated with Novartis’ spinal muscular atrophy gene therapy Zolgensma, following Novartis’ disclosure of the potential signal. The probe underscores regulator scrutiny of long-term safety outcomes for gene therapies, particularly malignancy risk that can emerge after extended follow-up. The agency’s decision adds pressure for ongoing pharmacovigilance and transparent risk communication for therapies that deliver permanent genetic changes. For biotech developers, the move reinforces the need for robust post-authorization monitoring plans that can detect rare but clinically significant adverse events over time.