Phase I of Infusion of Selected Donor NK Cells After Allogeneic Stem Cell Transplantation

In the mid 90's, it has been shown that donor lymphocyte infusions (DLI), when given for Chronic Myelocytic Leukemia (CML) that has relapsed after conventional allogeneic stem cell transplantation (SCT), result in a high incidence of durable cytogenetic and molecular remissions. However, regular documented effects are the occurrence of secondary aplasia and/or graft-versus-host disease (GVHD) including the post RIC situation. These effects are related to the high content of cytotoxic T cells in the DLI. Attempts to deplete CD8+ T-cells from DLI have been conducted with promising results but are not totally satisfactory. More recently the infusion of r-IL2 ex-vivo activated autologous or allogeneic NK-selected cells have been studied and the safety established in patients presenting various malignancies. Indeed, NK are thoroughly characterized in terms of genotype, phenotype and function. Although a handful of clinical-grade reagents and devices exist that give access to the human NK cell compartment, an immuno-selection device exists that allows for the selection of NK cells from various types of hematopoietic cell collections in view of clinical applications: the process produces CD3-/CD56+ cells in two steps and have been used in the previous experiences.