Study of Gene Modified Donor T Cell Infusion in Patients With Recurrent Disease After Allogeneic Transplant

Unmanipulated donor lymphocyte infusion (DLI) is used after stem cell transplantation to treat and prevent relapse, to prevent infections and to establish full donor chimerism. The addition of mature T cells which exhibit a broad repertoire of T cell immunity against viral and cancer antigens, might provide a clinical benefit. However, an expected side effect of the presence of mature T cells is the potential occurrence of acute graft-versus-host disease (aGVHD). BPX-501 contains genetically modified donor T cells that have an inducible safety switch iCasp9 suicide gene. Evidence has emerged that escalating DLI has achieved higher clinical response rate with lower GVHD occurrence. Optimization of DLI dose and schedule as well as strategies of donor T-cell manipulation may lead to the consistent ability to separate GVHD from GvL (graft-versus-leukemia) activity and improve the safety of DLI treatment.