alphaspirit - stock.adobe.com
bluebird bio Suspends Studies of Sickle Cell Disease Gene Therapy
The company placed the studies on temporary suspension after a patient who was treated with its gene therapy over 5 years ago was diagnosed with acute myeloid leukemia.
Pharmaceutical company bluebird bio recently announced that it suspended Phase 1/2 and Phase 3 studies of LentiGlobin gene therapy for sickle cell disease due to a suspected unexpected serious adverse reaction.
The suspected unexpected serious adverse reaction, or SUSAR, involved myelodysplastic syndrome, a cancer-like disease of the bone marrow, in a patient from Group C of HGB-206. The event was reported to bluebird bio last week and is currently being analyzed.
Since then, bluebird bio temporarily suspended two of its ongoing trials.
The first trial, HGB-210, is a Phase 1/2 open-label study designed to evaluate the efficacy and safety of LentiGlobin for sickle cell disease. The second trial, HGB-210, is a Phase 3 open-label study designed to evaluate the efficacy and safety of LentiGlobin gene therapy in patients between two years of age and 50 years of age diagnosed with sickle cell disease.
Similarly, the company reported that one serious adverse event of myelodysplastic syndrome was found in a patient who received LentiGlobin in its Phase 1/2 HGB-206 study of patients with sickle cell disease in December 2018.
Analysis of the patient’s cells showed no evidence of vector-mediated insertional oncogenesis, the company explained.
Notably, no cases of hematologic malignancy have been reported in any patient who has received the gene therapy so far.
“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, chief executive of bluebird bio, said in the announcement.
“We are committed to fully assessing these cases in partnership with the healthcare providers supporting our clinical studies and appropriate regulatory agencies. Our thoughts are with these patients and their families during this time,” Leschly continued.
The pharmaceutical company is currently investigating the cause of the patient’s acute myeloid leukemia to determine if there is any connection to the use of the BB305 lentiviral vector, which was used in the manufacturing of LentiGlobin.
Betibeglogene autotemcel, licensed as Zynteglo in the European Union and the United Kingdom, is used for the treatment of rare blood disorder beta thalassemia and was manufactured using the same BB305 lentiviral vector as LentiGlobin.
Therefore, bluebird bio made the decision to temporarily suspend marketing of Zynteglo while researchers assess the acute myeloid leukemia case.
The company will work with the independent safety review board monitoring the company’s studies, the FDA, and the European Medicines Agency (EMA) to complete the current ongoing investigation.
Sickle cell disease is a blood disorder in which the red blood cells take on a curved, sickle shape rather than the typical round shape. The disease causes various symptoms in patients, such as acute pain, joint or organ damage, impaired cognitive function, and reduced life expectancy.
According to the CDC, it is estimated that nearly 100,000 Americans are affected by sickle cell disease.
In November 2020, bluebird bio confirmed its general agreement with FDA that the clinical data package required to support its biologics license application submission for LentiGlobin will be based on data from patients in the HGB-206 study that have previously been treated.
FDA requested the use of drug products manufactured from sickle cell disease patient cells in addition to healthy donors, as well as commercial lentiviral vector to demonstrate drug product comparability, the company explained.
bluebird bio recently stated that it is adjusting its submission timing to late 2022. The company will work with FDA to uncover an approach to reviewing the CMC portion of a biologics license application submission and address the high unmet need in sickle cell disease.
