lovotibeglogene autotemcel (lovo-cel) gene therapy is an investigational one-time treatment being studied for sickle cell disease (SCD), that is designed to add functional copies of a modified form of the β-globin gene (β A-T87Q -globin gene) into a patient's own hematopoietic (blood) stem cells (HSCs). Once patients have the β A-T87Q -globin gene, their red blood cells (RBCs) can produce anti-sickling hemoglobin (HbA T87Q ) that decreases the proportion of HbS, with the goal of reducing sickled RBCs, hemolysis, and other complications. bluebird bio's clinical development program for lovo-cel includes the completed Phase 1/2 HGB-205 and ongoing Phase 1/2 HGB-206 and Phase 3 HGB-210 studies. bluebird bio is also conducting a long-term safety and efficacy follow-up study (LTF-307) for people who have been treated with lovo-cel in bluebird bio-sponsored clinical studies.