The U.S. Food and Drug Administration (FDA) has approved the first gene therapy for sickle cell disease based on the revolutionary gene-editing technology known as CRISPR. The treatment, called exa-cel or Casgevy, was developed by Vertex Pharmaceuticals and CRISPR Therapeutics. It works by using CRISPR to target the gene responsible for shutting off fetal hemoglobin, which can help healthy blood cells outcompete sickled cells and reduce the risk of blockages in small blood vessels. The FDA is also expected to make a decision on using exa-cel to treat beta thalassemia by March 2024. Another gene therapy called lovo-cel, developed by bluebird bio, has also been approved for sickle cell patients and works by introducing a new gene for hemoglobin that breaks down the chains formed by sickled cells, resulting in better blood flow.
These gene therapies provide new hope for patients with sickle cell and beta thalassemia, who currently rely on lifelong and repeated blood transfusions. The treatments offer the potential for a functional cure and the reduction of painful episodes and hospital visits. While the procedures involved in the treatment are grueling and time-consuming, with months of tests, invasive bone marrow transplants, and high-dose chemotherapy, the potential benefits are significant. Experts believe that most patients will find the treatments worth it, as they can significantly improve their quality of life and potentially prevent long-term organ damage associated with sickle cell disease. The FDA has also requested that both companies follow patients for 15 years to document any potential long-term effects, including cancers. Overall, the approval of these gene therapies marks a major breakthrough in the treatment of genetic diseases and highlights the transformative potential of CRISPR gene editing technology. Overall, the approval of these gene therapies marks a major breakthrough in the treatment of genetic diseases and highlights the transformative potential of CRISPR gene editing technology.