Fludarabine-containing regimens severely impair peripheral blood stem cells mobilization and collection in acute myeloid leukaemia patients

We studied the effects of an intensified induction/consolidation treatment containing fludarabine (ICE/FLAN/FLAN) on the mobilization and collection o f peripheral blood stem cells (PBSC) in 31 consecutive untreated acute myel oid leukaemia (AML) patients. The complete remission (CR) rate was comparab le to classic inductions (68% after ICE; 84% after ICE-FLAN I). To mobilize PBSC, 19 patients received 10 mu g/kg/d of granulocyte-colony stimulating factor (G-CSF) starting at day 13 after FLAN, 13 (69%) of whom were found t o be nonmobilizers. When a second G-CSF administration was performed in 10/ 13 patients mobilization was either not achieved (8/10) or was considered i nsufficient (<1 x 10(6) CD34(+) cells/kg) (2/10) and all 13 were subsequent ly submitted to bone marrow harvest. The harvest was considered adequate in 12/13 (92%) patients and autologous BMT (ABMT) has so far been performed i n 10/12 cases with a mean of 8.6 x 10(8)/kg nucleated reinfused cells. The median times to neutrophil and platelet recovery after ABMT did not signifi cantly differ from those of two previous series of patients treated with AB MT without fludarabine-containing regimens. Adequate amounts of PBSC were o btained in 6/19 (31%) patients, who were then reinfused. Median times for p latelet recovery were significantly longer than in a previous series of 26 AML cases reinfused with PBSC after treatment with the ICE-NOVIA induction/ consolidation regimen (125 v 20 d to 20 x 10(9) plt/l. P < 0.02; 218 v 37 d to 50 x 10(9) plt/l, P < 0.02). In addition, times for platelet recovery a fter ICE/FLAN/FLAN were not significantly different from those in a previou s group treated with ABMT performed after ICE/NOVIA, without fludarabine. W e conclude that fludarabine-containing regimens severely impair mobilizatio n and collection of PBSC in AML patients and seem unsuitable when PBSC auto transplantation is programmed.