The U.S. Food and Drug Administration (FDA) has granted approval for the first gene-editing treatment, Casgevy, to be used in patients with sickle cell disease. This approval comes after a decade of advancements in CRISPR technology, which allows for the editing of human DNA. Casgevy, developed by Vertex Pharmaceuticals and CRISPR Therapeutics, uses Nobel Prize-winning CRISPR technology to edit a person's genes and treat the disease. The treatment was previously approved by regulators in the U.K.
Sickle cell disease is an inherited blood disorder that causes red blood cells to become misshapen and restrict blood flow, resulting in severe pain crises. It is estimated that around 100,000 Americans have this disease.
Casgevy works by editing a person's DNA to turn on fetal hemoglobin, a protein that normally shuts off shortly after birth. This helps red blood cells maintain their healthy shape. Clinical trials have shown that Casgevy eliminated pain crises in most patients. The FDA has approved the treatment for individuals aged 12 and older.
While the treatment itself is administered only once, the entire process takes several months. Blood stem cells are extracted and genetically modified in Vertex's lab before being infused back into the patient. Recipients then spend weeks in the hospital recovering. Vertex estimates that about 16,000 people with severe cases of sickle cell will be eligible for the treatment.
However, there are concerns about the accessibility and cost of the treatment. Vertex has set the price at $2.2 million per patient, which could be prohibitive for many. Additionally, the complexity of the procedure means that it will only be available at certain health facilities, such as academic medical centers.
In addition to Casgevy, the FDA has also approved a separate gene therapy called Lyfgenia by Bluebird Bio. This therapy works differently from Casgevy but is administered similarly and aims to eliminate pain crises in sickle cell disease patients aged 12 and older.
Overall, the approval of Casgevy represents a significant scientific advancement in the treatment of sickle cell disease. However, challenges remain in terms of accessibility and cost, and it remains to be seen how many patients will opt for a treatment that takes several months to complete and carries potential risks.