ENAGenomicsDonald B. Kohn, M.D., Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeleshttps://www.ebi.ac.uk/ena/browser/view/PRJNA1240240Homo sapiensAlpha thalassemia major (ATM) is an inherited blood disorder caused by the absence of all four α-globin genes (HBA2/1), resulting in severe anemia and lifelong transfusion dependence. While allogeneic hematopoietic stem cell transplant (HSCT) offers a potential cure, donor availability remains limited. We present a gene therapy approach for autologous HSCT, using lentiviral vectors (LVs) to deliver HBA2 under the regulation of optimized β-globin locus control region (LCR) enhancers, restoring α-globin expression. The best-performing LVs, EV-α and EV-α-UV, achieved 90-100% transduction efficiency in human hematopoietic stem and progenitor cells (HSPCs), optimal vector copy numbers, and a safe integration profile. ATM-derived HSPCs from three donors treated with these LVs yielded α/β-globin mRNA and chain ratios within the therapeutic range (~0.5+), and restored hemoglobin levels by 50 to 100%. These findings establish the safety and clinical potential of EV-α and EV-α-UV as a promising autologous stem cell gene therapy for ATM. Overall design: Erythroid cells differentiated from bone marrow derived hematopoietic stem and progenitor cells from 2 healthy donors and 1 donor with alpha thalassemia major. Some conditions from the alpha thalassemia major cells were transduced with different alpha globin lentiviral vectors desgined and produced in our laboratory.ENAfalseLentiviral Vectors for Hematopoietic Stem Cell Gene Therapy Restore α-Globin Expression in α-Thalassemia Red Blood CellsLentiviral Vectors for Hematopoietic Stem Cell Gene Therapy Restore α-Globin Expression in α-Thalassemia Red Blood Cells2025-09-242025-07-17PRJNA1240240GSE2925759606