Bluebird Bio has suspended its sickle cell gene therapy clinical trials after learning that a patient treated with one of its therapy developed cancer, Stat News reports.
According to Bluebird, the company learned last week that a patient treated with its LentiGlobin gene therapy five years ago has developed acute myeloid leukemia and that another patient has developed myelodysplastic syndrome, which can be a precursor to leukemia. It adds that there are investigations into the causes of the patients' diseases. "The safety of every patient who has participated in our studies or is treated with our gene therapies is the utmost priority for us," Nick Leschly, the CEO of Bluebird, says in a statement.
Stat News notes that in 2018 a sickle cell disease patient treated three years prior with Bluebird's LentiGlobin was also reported to have developed myelodysplastic syndrome. The cause of the syndrome in that patient was traced to the chemotherapy given in preparation for the gene therapy. These new cases, Stat News says, may revive cancer risk concerns for gene therapy patients.
The company notes that no hematologic malignancies have been reported related to its β-thalassemia treatment that is approved in Europe, though it is still suspending its sale as it relies on the same lentiviral vector as the LentiGlobin therapy.