Evaluation of Efficacy and Safety of a Single Dose of CTX001 in Participants With Transfusion-Dependent β-Thalassemia and Severe Sickle Cell Disease

This study evaluates CTX001 (exagamglogene autotemcel), a gene-editing therapy using CRISPR technology, for people with transfusion-dependent beta-thalassemia (TDT) or severe sickle cell disease (SCD). The treatment aims to reduce or eliminate the need for blood transfusions by reactivating fetal hemoglobin production. You may be eligible if: - You are between 12 and 35 years old - You have a confirmed diagnosis of transfusion-dependent beta-thalassemia or severe sickle cell disease - For TDT: you have required at least 100 mL/kg/year or 10 units/year of packed red blood cell transfusions over the past 2 years - For SCD: you have had at least 2 severe vaso-occlusive crises (VOCs) per year for the past 2 years - You are eligible for an autologous stem cell transplant You may NOT be eligible if: - A matched related stem cell donor (10/10 HLA-matched) is available and willing - You have previously had a stem cell transplant - You have a significant active infection - For TDT: you have associated alpha-thalassemia with more than one alpha deletion - For SCD: you have untreated moyamoya syndrome Talk to your doctor to see if this trial is right for you.