The FDA is conducting a serious investigation concerning multiple cases of blood cancers among patients who received Bluebird Bio's innovative gene therapy, Skysona, for treating the rare neurological condition known as cerebral adrenoleukodystrophy (CALD). Initially approved by the U.S. regulatory body in 2022, Skysona, or elivaldogene autotemcel, was hailed as the first effective treatment capable of slowing down the deterioration of neurological functions in boys suffering from this life-threatening disorder.
Skysona has recently come under scrutiny due to increasing reports linking it to serious forms of hematological cancers, including dangerous conditions like myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). According to the latest updates from the FDA, these incidents appear to be connected to the treatment, raising alarming questions about the safety of this therapy.
The FDA is now evaluating the potential need for more regulatory actions concerning Skysona, following what they describe as "additional reports" pointing to these severe side effects. The agency’s notice highlights findings from clinical trials where cases of blood cancers were diagnosed anywhere between 14 and 92 months post-treatment, which is notable since the therapy was priced at $3 million when it was launched.
It is important to note, as outlined by the FDA, the risk of hematological malignancies associated with Skysona was known prior to its approval. This risk is clearly emphasized within the therapy's boxed warning section on its approved labeling, wherein experts explain how the genesis of these cancers may result from activation of certain cancer-related genes. This activation occurs when the lentiviral vector utilized in the gene therapy integrates itself within the patient’s DNA, potentially leading to dire consequences.
Considering these risks, the FDA advises healthcare providers to be cautious when determining the best treatment options for young patients diagnosed with CALD. The agency recommends evaluating other alternatives, prominently allogeneic hematopoietic stem cell transplant (allo-HSCT), especially for children who may have access to suitable and willing donors. The message is clear: safety should always be the priority.
This investigation has gained momentum following alarming findings published last month in The New England Journal of Medicine, which indicated seven out of 67 boys enrolled in clinical trials for Skysona had developed some form of blood cancer. The existence of such cases prior to the therapy's widespread usage has raised eyebrows within the medical community and regulatory frameworks.
CALD, the condition for which Skysona is intended, is globally rare, affecting approximately one in 20,000 to 50,000 people, predominantly boys aged between three and twelve years. Without treatment, nearly half of the children diagnosed with CALD may die within five years from the onset of symptoms.
Skysona has provided hope where previously there was none, especially since traditionally the only available option was allo-HSCT. While this transplant procedure offers lifesaving potential, it also poses substantial risks, including the possibility of death and severe complications, especially when no matched donor is available. Especially concerning are the elevated risks associated with transplant procedures when alternatives, like Skysona, are available.
On the commercial front, Bluebird Bio reported recently its challenges to establish and maintain viability as a business, noting revenues of just over $10 million for the third quarter of the year. Faced with these mounting challenges, the company announced it would reduce costs, which included laying off 25% of its workforce. This effort indicates the uphill battle Bluebird faces as it navigates through scrutiny and demand for accountability.
While the investigation continues, transparency remains key. The safety of patients receiving Skysona is of utmost importance, and the FDA's proactive scrutiny adds another layer of accountability as it assesses the need for appropriate responses to these concerning cancer cases. Parents of children with CALD and healthcare providers are watching closely—the outcomes may heavily influence treatment decisions moving forward.
The FDA's findings not only spotlight the existing safety concerns surrounding Skysona but also urge the pharmaceutical industry to remain vigilant and proactive about potential side effects when it engages with novel treatments. Investigations like these are necessary to instill public trust and to fine-tune the processes with which groundbreaking medical treatments are rolled out.
