A Safety and Efficacy Study Evaluating ET-01 in Subjects with Transfusion Dependent Β-Thalassaemia

Key Inclusion Criteria: * Subjects and/or legal representative fully understand and voluntarily sign informed consent forms. * Diagnosis of transfusion dependent β-thalassemia (β-TDT) as defined by protocol. * Be not appropriate to receive conventional allogeneic hematopoietic stem cell transplantation. * Lansky/Karnofsky score ≥ 70%. * Eligible for hematopoietic stem cell transplantation and conditioning with busulfan as per investigator's judgement. Other protocol defined inclusion criteria may apply. Key Exclusion Criteria: * Subjects with associated α-thalassemia. * Subjects with any clinically significant acute or uncontrolled infections. * History of uncontrolled epilepsy or other mental disorders. * Previous treatment with allogeneic bone marrow transplantation or gene therapy. Other protocol defined exclusion criteria may apply.