FDA restricts use of gene therapy Skysona (elivaldogene autotemcel) due to blood cancer risk concerns – Bluebird Bio

The FDA has updated Skysona’s indication, allowing it to be used only in patients who do not have an available human leukocyte antigen (HLA)-matched donor for stem cell transplant.

The one-time therapy is approved to treat cerebral adrenoleukodystrophy (CALD), a rare inherited neurological disorder in which the accumulation of harmful fatty acids in the bloodstream damages the protective myelin sheath around nerve fibers.

The FDA decided that Skysona should not be used in patients with alternative treatment options due to concerns of an increased risk of blood cancer. Hematologic malignancies, including life-threatening cases of myelodysplastic syndrome and acute myeloid leukemia, are a known risk factor for Skysona since its approval in 2022 and are reflected in a boxed warning on the drug’s label.

The malignant transformation is believed to be likely caused by an insertion of Skysona’s lentiviral vector into the human genome.