ß-Thalassemia Major with Autologous CD34+ Hematopoietic Progenitor Cells Transduced with TNS9.3.55 a Lentiviral Vector Encoding the Normal Human ß-Globin Gene

Patients will receive Filgrastim followed by apheresis of peripheral blood stem cells. CD34+ cells will be purified and transduced ex vivo. Transduced cells will be frozen in several aliquots whenever possible while vector copy number determination and biosafety testing are performed. Patients will be treated in the outpatient and/or inpatient units, and receive intravenous busulfan (8mg/kg) as non-myeloablative conditioning. Patients will be administered 2-12 x 10\^6 transduced CD34+ cells per kg in 1 or several infusions. A back-up of 2 x 10\^6 untransduced CD34+ cells per kg will be preserved for every patient.