ABSTRACT
We and others have investigated the use of autologous hematopoietic stem cell transplantation (HSCT) in the treatment of chronic myeloid leukemia (CML).1 Originally, this approach was based on the observation that benign hematopoietic stem cells coexist with their malignant counterparts in at least some CML patients.2-5 Autologous transplant approaches included preparation with highdose chemoradiotherapy followed by infusion of unmanipulated cells,6 marrow cells purged ex vivo with mafosfamide,7 recombinant human interferon- (IFN-),8 or antisense oligodeoxynucleotides to c-myb,9 and marrow cells purged by in vitro culture.10 Other approaches included in vivo purging with single-agent or combination chemotherapy.11,12
Prolonged survival following autologous HSCT using one of several approaches has been reported.13 A high incidence of complete or major cytogenetic responses following autolo-
gous HSCT has also been observed.14 In most cases, however, cytogenetic responses have not been durable, and the malignant clone has not been eradicated.15 Efforts to capitalize on the high rate of initial major cytogenetic remission following autologous HSCT are underway. These include the use of autologous HSCT followed by recombinant IFN-, interleukin-2 (IL2)-based immunotherapy,16 and, most recently, non-myeloablative allogeneic HSCT.17
