Both Vertex Pharmaceuticals Inc.’s Casgevy (exagamglogene autotemcel, exa-cel) and Bluebird Bio Inc.’s Lyfgenia (lovotibeglogene autotemcel, lovo-cel) received U.S. FDA approval Dec. 8, providing 16,000 American sickle cell patients who have recurring vaso-occlusive events with access to the first cell-based gene therapies.