The US Food and Drug Administration has approved a new indication for Casgevy, a cell-based gene therapy for two blood disorders, making it available to individuals as young as two years. The disorders are sickle cell disease, a rare inherited blood disorder, and transfusion-dependent beta thalassaemia. Casgevy (exagamglogene autotemcel) was first approved by the FDA in 2023 for children with sickle cell disease from the age of 12 years.
“Earlier access to the transformative potential of this therapy will allow clinicians and families to consider treatment before years of cumulative damage from these life-shortening diseases take hold,” Haydar Frangoul, a medical director at HCA Healthcare Inc, said in a prepared statement. The FDA approval was announced on 1 July.
Sickle cell disease is a common genetic disorder caused by a mutation in the HBB gene which encodes a subunit of haemoglobin in red blood cells. This causes the cells to change shape and hamper the delivery of oxygen. It can lead to organ damage and other complications. Beta-thalassemia is also caused by mutations in the HBB gene. Transfusion-dependent beta-thalassemia is the most severe type where patients may require frequent blood transfusions and iron chelation therapy to remove toxic iron from the body.
Casgevy consists of a patient’s own cells which are edited using the CRISPR/Cas9 tool and directed to a specific spot in DNA. The edits increase foetal haemoglobin and address the underlying cause of the disease, according to the FDA.
Casgevy was shown to be safe and effective in 11 patients with sickle cell disease and 15 patients with beta-thalassaemia. The patients were five years to less than 12 years old. This data was then extrapolated to younger patients with the result that the indication has been expanded to two years and above.
Casgevy as developed by Vertex Pharmaceuticals Inc and CRISPR Therapeutics AG.
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