Clinical trial and manufacturing outline. (A) Schematic of clinical trial donor collection, GMP manufacturing, and infusion process. The process entailed the following: (1) collecting HCT-donor peripheral blood mononuclear cells (PBMC) by apheresis; (2) removing CD45RA⁺ cells from PBMC to reduce the risk of GVHD associated with donor naïve T cells and to skew the product toward a central memory T-cell (T_CM) phenotype to enhance in vivo persistence; (3) separating the T cells into predominantly CD4⁺ and CD8⁺ fractions to control the CD4:CD8 ratio in the cell product; (4) stimulating and transducing CD4⁺ and CD8⁺ T cells in parallel cultures; (5) sorting for T cells expressing the TCR and CD34 tag on a fluorescence-activated cell sorter; (6) expanding; (7) enriching transduced cells using CD34⁺ antibody–conjugated immunomagnetic beads and a magnetic column; and (8) evaluating the final product. Refer to supplemental Method online for additional details. (B) CONSORT diagram depicting patient enrollment and treatment. The reasons for not treating patients included the following: 2 patients declined treatment within a phase 1 trial, 1 patient’s unrelated donor was not available, 1 patient had graft rejection before relapse, and 1 patient was not treated because of administrative reasons.