Base Editing of HBG1 and HBG2 Promoters for Sickle Cell Disease

promoters and inhibit BCL11A binding without altering BCL11A expression, yielding a switch in hemoglobin production from sickle hemoglobin (HbS) to antisickling fetal hemoglobin (HbF).

viable CD34+ cells per kilogram of body weight). The primary efficacy end point was freedom from severe vaso-occlusive crises for 12 consecutive months, starting later than 60 days after the last red-cell transfusion. This interim analysis was unplanned; here, we describe safety, editing, engraftment, and hemoglobin production and the number of severe vaso-occlusive crises starting later than 60 days after the last red-cell transfusion.