FDA approves CRISPR-based gene therapy for beta-thalassemia

The US Food and Drug Administration (FDA) has approved the drug Casgevy based on CRISPR/Cas9 genome editing technology for the treatment of beta-thalassemia. This was reported by Pharmaceutical Gazette with reference to Vertex Pharmaceuticals, which developed the gene therapy in collaboration with CRISPR Therapeutics.

This is Casgevy's second indication registered by a US regulator. In December, the FDA granted approval for the drug as a treatment for sickle cell anemia, making it the first approved CRISPR-based treatment.

The introduction of Casgevy is a complex process that involves extracting human stem cells and editing genes in them using CRISPR technology in a specialized laboratory. The edited genes are put back into the patients body. The drug works for both sickle cell anemia and thalassemia, as both diseases are caused by an error in the genes responsible for hemoglobin synthesis.

Vertex said it is working to open a network of health centers in the U.S. where patients can receive the drug. Today, only nine authorized medical centers can administer the gene therapy into the body. Casgevy will cost $2.2 million.

Beta-thalassemia is an inherited disease characterized by a genetic defect in the synthesis of beta-polypeptide chains, which leads to impaired synthesis of hemoglobin A. This is fraught with a number of consequences - from the development of severe anemia to bone marrow hyperactivity. Treatment of the pathology today includes lifelong transfusion of red blood cell mass, removal of the spleen or the use of iron chelators.

In 2022, against beta-thalassemia, the FDA approved the gene therapy Zynteglo by Bluebird Bio. The administration of this drug is different from Casgevy: stem cells from bone marrow taken from the patient are treated with viral vectors with the desired hemoglobin gene and put back into the body. The price of Zynteglo is $2.8 million.