Spinal FrontiersPowered by NSpineFDA investigates tumours after Zolgensma gene therapy for SMA
The FDA is investigating postmarketing reports of tumours in children treated with Zolgensma. Some reports show tumours caused by the product itself: the gene therapy's vector DNA had inserted next to or inside the cancer gene GLI1. Reported tumours involved the brain, spinal cord and nerves, the spinal and paraspinal regions, and the kidney. The FDA says the benefits still outweigh the risks for approved uses, and that treated patients and trial participants should be monitored for tumour formation.
Details
- Company
- Novartis Gene Therapies
- Product
- Zolgensma (intravenous) and Itvisma (intrathecal), onasemnogene abeparvovec, AAV9 gene therapy for spinal muscular atrophy
- FDA (6 Nov 2026)
- Three cases involved GLI1-associated tumours. In two, the tumour tissue contained Zolgensma vector DNA integrated into the patient's genome, upstream of or within GLI1. In the third, the mechanism is still under investigation. The FDA is evaluating whether regulatory action is needed and is reviewing the prescribing information (which already lists a theoretical risk of tumours from vector integration) and Novartis's long-term follow-up studies. The risk applies to Itvisma as well (same vector and construct; approved 24 Nov 2025 for patients aged 2 and over); no tumour has been reported after Itvisma so far.
- Novartis (statement of 5 Nov 2026)
- More than 6,000 patients have received Zolgensma since approval in 2019. Novartis has received 9 reports of tumours in treated patients. Two show evidence of vector DNA integration; both patients were treated and remain under monitoring. Novartis says it notified health authorities in each case. We found the statement through SMA Europe; we did not find it on novartis.com as of 7 Nov.
- UK National MDT for Zolgensma (4 Nov 2026, via SMA UK)
- Three of the nine tumours have been tested: two are linked to Zolgensma and one appears unrelated. Routine care and follow-up should stay the same, and no additional scans, tests or monitoring are needed at this time. Families with concerns should contact their neuromuscular team.
- Europe and Switzerland
- As of 7 Nov 2026 we found no public statement from the EMA, the MHRA or Swissmedic. SMA Europe says regulators are assessing the cases.
- Earlier published case
- Retson et al., Molecular Therapy 2023: a low-grade epithelioid intramedullary tumour at the conus (T12), 14 months after treatment; the authors found no evidence that vector integration caused it, but the test was limited by very little tumour DNA.
- For spine teams
- Reported tumours include spinal and paraspinal sites, and many treated children are seen by spine teams for scoliosis. Follow the FDA and your national guidance; report any tumour in a treated patient to Novartis Gene Therapies and to your regulator (US: 1-833-828-3947 or FDA MedWatch).
FDA safety communication, 6 Nov 2026 →
Novartis statement via SMA Europe, 5 Nov 2026 →
UK National MDT update via SMA UK, 4 Nov 2026 →
Retson et al., Mol Ther 2023 (PMID 37598295) →Sources checked
Full briefing in Safety in Focus: sources, summary and what is unknown →