Granulocyte colony-stimulating factor given in addition to interferon- α to mobilize peripheral blood stem cells for autologous transplantation in chronic myeloid leukaemia

Abstract

In order to potentially mobilize and harvest the Ph- cells observed in most patients with chronic myeloid leukaemia (CML) during interferon-α (IF- α) therapy. G-CSF (filgrastim). 5 μg/kg/d, was administered subcutaneously together with IF-α to 30 CML patients in haematological remission but with various degrees of cytogenetic remission, after IF-α therapy. Peripheral blood stem cells (PBSC) were harvested using standard aphereses from day 5 of G-CSF. Patients underwent one to four (median three) aphereses. Median total yields/kg were 7.6 (range 3.8-25) x 108 MNC, 3.4 (0-140) x 106 CD34+ cells, and 17 (1.1-107) x 104 CFU-GM. No patient had a significant increase in the percentage of Ph+ cells in the bone marrow under G-CSF therapy. The percentage of Ph+ cells in apheresis products tended to decrease between the first and the last apheresis (P = 0.05), 14 patients who were not responsive to IF-α were transplanted after conditioning with busulphan 16 mg/kg and melphalan 140mg/m2. Median time to neutrophils >0.5x109/l was 20d (16- 114d) and to platelets > 50 x 109/l 18d (12-149d). Nine patients had a major cytogenetic response post graft, which correlated with the amount of Ph+ cells reinfused with the graft (P=0.02). We conclude that this procedure is feasible, allowing the harvest of enough PBSC, some of them Ph- in patients who responded to IF-α, to allow autologous transplantation.