A Phase 1 Study Evaluating Gene Therapy by Transplantation of Autologous CD34+Stem Cells Transduced Ex Vivo with the LentiGlobin BB305 Lentiviral Vector inSubjects with Severe Sickle Cell Disease

The purpose of this study is to evaluate the safety and ability of the autologous stem cell transplant with gene modified stem cells to treat sickle cell disease. The goal is to determine if a sufficient amount of normal hemoglobin (without sickling) can be produced after the gene modified stem cells are returned to the body. This study may provide information on the usefulness of LentiGlobin® BB305 as a future treatment for sickle cell disease. Genes, which we inherit from our parents, are pieces of information which provide the blueprints for all the proteins that keep our cells and ourselves alive. Sickle cell disease is caused by a beta globin gene that does not behave in a normal and expected way. This is due to a change in the gene (mutation) that leads to abnormal red blood cells, in turn leading to anemia, pain and possible damage to your internal organs. The study will enroll up to 20 subjects total across several clinical centers. Your participation in this study will be about 27 months from the time you sign a consent form to the last evaluation. At the end of the study, you will be invited to participate in a separate long-term follow-up study that will last 13 more years. You will be asked to sign a separate consent form for that long-term follow up study.

Are you Eligible? (Inclusion Criteria)

• Be ≥ 18 years of age.
• Have you been diagnosed with Sickle Cell Diseas?
• Have you been to the hospital at least 4 times in the past 24 months?
• Have you been treated and followed for at least the past 24 months in medical center(s) that maintained detailed records on SCD history?