Novartis acknowledges seven tumour cases in children treated with Zolgensma SMA gene therapy
Novartis has reported seven previously unknown instances of tumour development in paediatric patients who received its spinal muscular atrophy gene therapy, Zolgensma.
Novartis has acknowledged seven cases in which tumours were identified in children who had previously received Zolgensma (onasemnogene abeparvovec), its adeno-associated virus (AAV) gene therapy approved for spinal muscular atrophy (SMA). The cases were described as previously unknown — meaning they were not identified during the original clinical trial programme — and were reported by STAT News on 5 November 2026.
Zolgensma delivers a functional copy of the SMN1 gene via an AAV9 vector. The therapy has been in clinical use since FDA approval in 2019 and has been administered to thousands of children worldwide. AAV-based gene therapies carry a theoretical risk of insertional mutagenesis, in which vector integration near a proto-oncogene could, in principle, contribute to tumour formation, though establishing causality in individual cases is complex.
Novartis has not, based on the available reporting, stated a confirmed causal link between Zolgensma and the tumours. The number of affected individuals relative to the total treated population has not yet been disclosed in full detail in public reporting. Regulatory authorities including the FDA and EMA are expected to review the data as part of ongoing pharmacovigilance obligations.
This story is developing. The lede text from STAT News is behind a paywall, and the full case report details — including tumour types, ages at onset, and time since treatment — have not been confirmed in publicly available sources at time of publication. Genetic Current will update as further information emerges.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
Zolgensma is a gene therapy used to treat spinal muscular atrophy (SMA), a rare inherited condition that weakens muscles. It works by delivering a corrected copy of a faulty gene into the body using a modified virus. The company that makes it, Novartis, has reported that seven children who were treated with Zolgensma were later found to have tumours. It is not yet confirmed whether the therapy caused the tumours. Researchers and medicines regulators will now review the data carefully. Gene therapies are monitored closely over many years after they are approved, precisely to detect any long-term effects that could not be seen in shorter trials. This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
Read the original reporting — these are the public sources this summary draws from.
-
Primary source Stat News · 2026-11-05STAT+: Novartis cites cases of previously unknown tumors possibly tied to its SMA gene therapy
-
Stat News · 2026-11-06STAT+: Pharmalittle: We're reading about a Novartis gene therapy, faster U.K. drug reviews, and more