The FDA that it is investigating reports of blood cancers -- including life-threatening cases of myelodysplastic syndrome and acute myeloid leukemia -- in patients with early, active cerebral adrenoleukodystrophy (CALD) who were treated with elivaldogene autotemcel (eli-cel; Skysona).
The reported cases came from clinical trials. Cancer diagnoses were 14 to 92 months post-treatment and appeared to be linked with the autologous hematopoietic stem cell-based gene therapy.
In 2022, the FDA granted accelerated approval to eli-cel to treat CALD in boys ages 4 to 17 years. Childhood CALD is a rare debilitating form of adrenoleukodystrophy that generally occurs in young boys. It's caused by a mutation in the ABCD1 gene that leads to the overproduction of very long-chain fatty acids primarily in the white matter of the brain and spinal cord that destroys myelin.
The treatment demonstrated long-term effectiveness, but that benefit came with a risk of developing blood cancer, according to data from studies published last month.
The FDA is now investigating the risk of hematologic malignancies with serious outcomes -- like hospitalization, the requirement for allogeneic hematopoietic stem cell transplantation, or death -- and is evaluating the need for further regulatory action.
Providers should carefully consider other treatments including allogeneic hematopoietic stem cell transplant for patients who have a suitable and willing human leukocyte antigen (HLA)-matched donor before deciding to treat a child with eli-cel, the FDA said.
Eli-cel's prescribing information includes a of the serious risk of developing hematologic cancers. "Patients and clinical trial participants receiving treatment with Skysona should be monitored lifelong for hematologic malignancy," the FDA noted.
"Early diagnosis of hematologic malignancy can be critically important," the agency added. "Therefore, patients should be closely monitored with complete blood counts at least every 3 months and through assessments for evidence of clonal expansion or predominance at least twice in the first year after Skysona administration and annually thereafter, and bone marrow evaluations should be considered as clinically indicated."
Eli-cel's approval included a postmarketing requirement for a 15-year follow-up prospective study to assess long-term safety and the risk of secondary malignancies occurring after treatment. The study includes monitoring for clonal expansion.