The US Food and Drug Administration yesterday approved a pair of gene therapy treatments for sickle cell disease, a group of inherited red blood cell disorders caused by mutations in a gene that produces an oxygen-carrying protein known as hemoglobin.
One of the treatments, called Casgevy, is based on breakthrough CRISPR technology—a Nobel Prize-winning gene-editing tool (see 101, w/video)—and is the first approved gene-editing therapy in the US.Codeveloped by Vertex Pharmaceuticals and CRISPR Therapeutics, Casgevy involves harvesting cells from a patient's bone marrow, editing the cells in a lab using CRISPR technology, and inserting the modified cells back into the patient's body. Read one man's account of being among the first people to experience the CRISPR-based treatment here.
The second treatment, developed by Bluebird Bio and called Lyfgenia, uses a harmless virus to introduce a gene into a patient's body to help produce a hemoglobin substitute. Both Casgevy and Lyfgenia have been approved for people 12 years and older.
Sickle cell disease (see overview) affects more than 100,000 Americans per year and 20 million people worldwide.