Collection of Ph-negative progenitor cells with granulocyte-colony stimulating factor in patients with chronic myeloid leukaemia who respond to recombinant alpha-interferon.

This study aimed to demonstrate that sufficient Ph-negative blood progenitors could be collected following administration of glycosylated rhG-CSF (lenograstim) to patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukaemia (CML) who responded to recombinant alpha-interferon (α-IFN) (Ph-positive marrow metaphases < 35%). 23 patients received lenograstim (150 μg/m2) once daily for a median of 9 d. Peak circulating numbers of white blood cells (36.4 × 109/l), CD34+ cells (24/μl) and colony-forming unit-granulocyte-macrophage (CFU-GM; 1346.5/ml) occurred at a median of day 8, day 8 and day 7, respectively. Two to six (median three) leukaphereses (LK) were performed from days 5 to 12. The median number of mononuclear cells (MNC), CD34+ cells and CFU-GM collected per patient was 7.35 × 108/kg, 2.72 × 106/kg and 10.23 × 104/kg, respectively. 22/23 patients had LK which contained either 104 CFU-GM/kg and/or 106 CD34+ cells/kg; 47 LK (from 20/22 patients) were evaluable for cytogenetics. The median percentage of Ph-positive cells was 0, and 43/47 LK (91%) contained < 35% Ph-positive cells; 25 (53%) were entirely negative. Sixteen of 20 evaluable patients had one or more LK with < 35% Ph-positive cells, and 12 had at least one 100% Ph-negative LK. Mobilization and collection of Ph-negative cells were not influenced by the dose or duration of α-IFN administration before (or during) lenograstim administration or by the quality of cytogenetic response (complete v major) during lenograstim administration. No significant side-effects were observed. Thus, lenograstim administration can result in satisfactory Ph-negative blood progenitor cell collection. Autologous transplantation of such cells may be used when indicated.