The therapy, called Casgevy, from Vertex Pharmaceuticals and CRISPR
Therapeutics, is the first medicine to be approved in the United States that uses the gene-editing tool CRISPR, which won its inventors the Nobel Prize in Chemistry in 2020.
The approval marks the first of two potential breakthroughs for the inherited blood disorder. The FDA on Friday also approved a second treatment for sickle cell disease, called Lyfgenia, a gene therapy from drugmaker Bluebird Bio. Both treatments work by genetically modifying a patient’s own stem cells.
Until now, the only known cure for sickle cell disease was a bone marrow transplant from a donor, which carries the ri§k of rejection by the immune system, in addition to the difficult process of finding a matching donor.
Casgevy, which was approved for people ages 12 and older, removes the need for a donor. Using CRISPR, it edits the DNA found in a patient’s stem cells to remove the gene that causes the disease. According to NBC News, the new therapy costs $2.2 million per patient.
Patients will have to be followed long-term before the experts call this a cure. Gene editing is expected to cost several million dollars per patient and may not be appropriate for everyone who has sickle cell disease. It would also not prevent the gene from being passed down to future generations.