UK Approves World's First CRISPR-Based Treatment for Blood Disorders

The groundbreaking gene-editing therapy, Casgevy, offers a potential cure for sickle cell disease and beta thalassemia, but concerns about accessibility and safety remain.

The UK's Medicines and Healthcare products Regulatory Agency has approved the world's first treatment using CRISPR gene-editing technology. The treatment, Casgevy, is for sickle cell disease and beta thalassemia, two blood disorders, and was developed by CRISPR Therapeutics and Vertex Pharmaceuticals.
Casgevy works by editing a patient's own blood stem cells to produce high levels of fetal hemoglobin, which is healthy and carries oxygen. This process involves disabling a DNA brake on the production of fetal hemoglobin, which is normally produced during fetal development but shuts down soon after birth.
The treatment process can take months and requires patients to spend weeks in the hospital before and after the therapy is administered. Patients must undergo a preparatory treatment with a chemotherapy drug to obliterate any native stem cells that might remain in their bone marrow, making room for the functional, CRISPR-edited cells to engraft and grow.
The U.S. Food and Drug Administration is expected to approve Casgevy on or before Dec. 8. The treatment is estimated to cost several million dollars, but an independent drug-pricing watchdog group has said Casgevy is likely to be cost-effective given the existing high cost of care for people living with sickle cell disease over their lifetime.
Despite the approval, concerns remain about the accessibility of the treatment due to its high cost and the potential for unintended genetic modifications with unknown side effects. However, the approval is seen as a landmark moment that opens the door for further applications of CRISPR therapies in the future.