Written by Emil Luca: The FDA has approved the thalassemia gene therapy named Zynteglo. This treatment was already approved in Europe in 2019. It is intended for the treatment of adult and pediatric patients with beta-thalassemia (also known as beta thalassemia major or Cooley’s Anemia) who require regular red blood cell transfusions.
Beta-thalassemia is a type of inherited blood disorder that causes a reduction of hemoglobin and red blood cells in the blood. It is caused by a change in the beta-globin gene, which causes the body to produce reduced or no beta-globin. In its severe form, the patient generally requires life-long blood transfusions as the standard course of treatment. This leads to iron overload, which causes several problems and needs chelation treatment.
What is this new thalassemia gene therapy?
ZYNTEGLO is a one-time gene therapy product to treat beta thalassemia, administered as a single dose. It is made specifically for each patient, using the patient’s own blood stem cells and adds functional copies of the beta-globin gene to these cells. This may allow the patient to produce sufficient hemoglobin to stop receiving regular transfusions.
The safety and effectiveness of Zynteglo were established in clinical studies that included adult and pediatric patients. Effectiveness was established based on achievement of transfusion independence, which is attained when the patient maintains a pre-determined level of hemoglobin without needing any transfusions for at least 12 months.
The most serious adverse reactions associated with Zynteglo included reduced platelet and white blood cell count, which may cause bleeding and increase susceptibility to infection. Patients should therefore be monitored for hypersensitivity reactions during Zynteglo administration and should be monitored for thrombocytopenia and bleeding.
There is a potential risk of blood cancer associated with this treatment that uses lentivirus for gene delivery; however, no cases have been seen in studies of Zynteglo. Patients who receive Zynteglo should have their blood monitored for at least 15 years for any evidence of cancer.
The writer declares no conflict of interest. Inquiries about this product are to be addressed to the manufacturer.
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