E7777 is a recombinant fusion toxin consisting of full-length human IL-2 fused to the catalytic domains of diphtheria toxin. This trial is designed to augment lymphodepletion prior to CAR-T cells by administration of a targeted immunotoxin against CD25-expressing T-cells. CD25 is expressed at high levels on Tregs but also on activated effector T cells. The use of the CAR-T cell product and associated apheresis and LD chemotherapy is considered standard of care (SOC).
This is a single institution Phase I study to determine the maximum tolerated dose (MTD) of E7777 when given prior to cyclophosphamide/fludarabine (CY/Flu) lymphodepletion (LD) chemotherapy and Kymriah, a commercial tisagenlecleucel product, for the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL) who are at a higher risk for failure of CAR-T therapy.