The First Crispr Medicine Is Now Approved in the US
Casgevy uses the Nobel Prize–winning technology Crispr to modify patients’ cells so that they produce healthy hemoglobin instead. The Crispr system has two parts: a protein that cuts genetic material and a guide molecule that tells it where in the genome to make the cut.To do this, a patient’s stem cells are taken out of their bone marrow and edited in a laboratory. Scientists make a single cut in a different gene, called BCL11A, to turn on the production of a fetal form of hemoglobin that typically shuts off shortly after birth. This fetal version compensates for the abnormal adult hemoglobin. The edited cells are then infused back into the patient’s bloodstream.A total of 45 patients have received Casgevy in a clinical trial. Of the 31 patients followed for two years, 29 have been free ...