COLLECTION OF PH-NEGATIVE PROGENITOR CELLS WITH GRANULOCYTE-COLONY-STIMULATING FACTOR IN PATIENTS WITH CHRONIC MYELOID-LEUKEMIA WHO RESPONDTO RECOMBINANT ALPHA-INTERFERON

This study aimed to demonstrate that sufficient Ph-negative blood prog enitors could be collected following administration of glycosylated rh G-CSF (lenograstim) to patients with Philadelphia chromosome (Ph)-posi tive chronic myeloid leukaemia (CML) who responded to recombinant alph a-interferon (alpha-IFN) (Ph-positive marrow metaphases < 35%). 23 pat ients received lenograstim (150 mu g/m(2)) once daily for a median of 9 d. Peak circulating numbers of white blood cells (36.4 x 10(9)/l), C D34(+) cells (24/mu l) and colony-forming unit-granulocyte-macrophage (CFU-GM; 1346.5/ml) occurred at a median of day 8, day 8 and day 7, re spectively. Two to six (median three) leukaphereses (LK) were performe d from days 5 to 12. The median number of mononuclear cells (MNC), CD3 4(+) cells and CFU-GM collected per patient was 7.35 x 10(8)/kg, 2.72 x 10(6)/kg and 10.23 x 10(4)/kg, respectively. 22/23 patients had LK w hich contained either 10(4) CFU-GM/kg and/or 10(6) CD34(+) cells/kg; 4 7 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 al pha-IFN administration before (or during) lenograstim administration o r by the quality of cytogenetic response (complete v major) during len ograstim administration. No significant side-effects were observed. Th us, lenograstim administration can result in satisfactory Ph-negative blood progenitor cell collection. Autologous transplantation of such c ells may be used when indicated.