FDA Probes Potential

FDA Probes Potential Life-Threatening Blood Cancer Risks Linked To Bluebird Bio's Skysona Gene Therapy

On Wednesday, the FDA raised concerns about life-threatening hematologic malignancies in patients treated with Bluebird Bio Inc’s  Skysona (elivaldogene autotemcel), a gene therapy for early, active cerebral adrenoleukodystrophy (CALD).

In September 2022, the FDA approved Bluebird Bio’s Skysona, aka eli-cel, to slow the progression of neurologic dysfunction in boys 4-17 years of age with early, active cerebral adrenoleukodystrophy (CALD).

The agency has received reports of myelodysplastic syndrome and acute myeloid leukemia linked to Skysona, with cases emerging 14 to 92 months post-treatment during clinical trials. As per new data released in October, seven out of 67 children treated with Bluebird Bio’s gene therapy for a severe neurological disorder in clinical trials developed blood cancers.

The FDA is investigating these risks, which include hospitalization, the need for allogeneic hematopoietic stem cell transplantation, and fatal outcomes. Healthcare providers are urged to consider alternative therapies, such as allogeneic stem cell transplants, for patients with suitable, matched donors before opting for Skysona treatment.

Patients and clinical trial participants treated with Skysona are advised to undergo lifelong monitoring for malignancies. To detect potential malignancies early, the FDA recommends regular complete blood counts every three months and assessments for clonal expansion twice within the first year post-treatment. Annual follow-ups and bone marrow evaluations are also advised as clinically necessary.

In September, Bluebird bio announced it is implementing a restructuring to optimize its cost structure and enable quarterly cash flow break-even in the second half of 2025. The restructuring is expected to result in a 20% reduction in cash operating expenses when fully realized in the third quarter of 2025, compared to the prior reporting period.