Purging of Bone Marrow with a Cocktail of Monoclonal Antibodies (VIB-pool) for Autologous Transplantation

Children with relapsed common acute lymphoblastic leukemia (ALL), B-non-Hodgkin lymphoma (B-NHL), and B-acute lymphocytic leukemia (B-ALL) have a very poor prognosis. If there is no HLA-identical donor, the patient should be considered for autologous bone marrow transplantation. Collected autologous marrow should be cleansed of contaminating tumor cells without destroying hemopoietic stem cells. We report here the results of our investigations with a cocktail of three monoclonal antibodies (VIL-A 1, VIB-C 5, and VIB-E 3 — the VIB pool — kindly given to us by Dr. Knapp of Vienna) concerning in vitro cytotoxicity against ALL blast cells and leukemic cells lines, lytic capacity with rabbit and human complement, and stem cell toxicity, together with our findings concerning the ex vivo purging of the marrow of four children.