UK becomes first country to approve Casgevy treatment for severe blood diseases

Recently, scientists aiming to develop a one-time treatment to relieve symptoms and possibly cure genetic diseases have found a successful solution. A new study reported the development of Casgevy, a gene editing tool using CRISPR-Cas9, to treat two serious blood diseases, namely sickle cell anemia and Mediterranean anemia (β-thalassemia).

a turning point

With Casgevy, the process involves editing the genes that code for hemoglobin in blood-producing stem cells. The UK medicines regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), became the first agency to approve the treatment following the success of clinical trials. Kay Davies, a geneticist at the University of Oxford, said: “This is a landmark approval that opens the door to further application of CRISPR therapies in the future for the potential treatment of many genetic diseases.”

According to the journal Nature, the treatment is administered intravenously. On the other hand, Vertex Pharmaceuticals and CRISPR Therapeutics developed the treatment. Citing Casgevy’s success, scientists found that the treatment relieved patients of debilitating pain in sickle cell disease and reduced or eliminated the need for regular blood transfusions in Mediterranean anemia (β-thalassemia).

The result is incredible

According to reports, 29 of 45 participants in the trial for sickle cell anemia were followed long enough to obtain interim results. Thanks to Casgevy, 28 of these people were found to be completely free of debilitating pain attacks for at least a year after treatment.

In trials for severe Mediterranean anemia (β-thalassemia), where standard treatment requires monthly blood transfusions, 42 of 54 people taking Casgevy reportedly participated in treatment long enough for interim results to be obtained. While 39 of them did not need a blood transfusion for a year, the remaining three experienced a reduction of over 70 percent in their need for blood transfusions.

The revolutionary aspect of this treatment is that it uses CRISPR-Cas9, a tool that won the Nobel Prize in Chemistry in 2020, to precisely edit genes in blood-producing stem cells. By targeting a specific gene called BCL11A, Casgevy triggers fetal hemoglobin production, which can relieve symptoms by improving oxygen supply to tissues.

Treatment is quite costly

However, some side effects, such as nausea and fever, were observed in participants in clinical studies, but no major safety concerns were identified. On the other hand, scientists have also expressed concerns about potential unwanted genetic modifications of CRISPR-Cas9. Other countries, including the United States and Europe, are reviewing Casgevy for approval. However, high cost and complex technology may limit accessibility, especially in low- and middle-income countries. Calculations show that the treatment could cost around $2 million per patient.