A Study Evaluating the Safety and Efficacy of the LentiGlobin BB305 Drug Product in β-Thalassemia Major Participants

Exclusion Criteria

• •Positive for presence of human immunodeficiency virus type 1 or 2 (HIV 1 and HIV 2).
• •A white blood cell (WBC) count \<3 × 10\^9/L, and / or platelet count \<100 × 10\^9/L if not due to hypersplenism.
• •Uncorrected bleeding disorder.
• •Any prior or current malignancy or myeloproliferative or immunodeficiency disorder.
• •Immediate family member with a known or suspected Familial Cancer Syndrome (including but not limited to hereditary breast and ovarian cancer syndrome, hereditary non-polyposis colorectal cancer syndrome and familial adenomatous polyposis).
• •Receipt of an allogeneic transplant.
• •Advanced liver disease, including persistent aspartate transaminase (AST), alanine transaminase (ALT), or total bilirubin value \>3 × the upper limit of normal, liver biopsy demonstrating cirrhosis, extensive bridging fibrosis, or active hepatitis.
• •Kidney disease with a calculated creatinine clearance \<30% normal value.
• •Uncontrolled seizure disorder.
• •Diffusion capacity of carbon monoxide (DLco) \<50% of predicted (corrected for hemoglobin).
• •A cardiac T2\* \<10 ms by magnetic resonance imaging (MRI).
• •Any other evidence of severe iron overload that, in the Investigator's opinion, warrants exclusion.
• •Clinically significant pulmonary hypertension, as defined by the requirement for ongoing pharmacologic treatment or the consistent or intermittent use of supplemental home oxygen.
• •Participation in another clinical study with an investigational drug within 30 days of Screening.
• •Any prior or current malignancy or myeloproliferative disorder.
• •Prior receipt of gene therapy.