Efficacy of Further Attempts to Mobilize CD34+ Peripheral Stem Cells with Alternative Procedures after Primary Failure

19 patients who failed the target collection of at least 2.5 x 10( Power6) CD34+ cells/kg underwent further mobilization procedures either with granulocyte-colony-stimulating factor (G-CSF) alone after failure to chemotherapy plus G-CSF (group 1), or with chemotherapy plus G-CSF (group 2), or with high-dose G-CSF (24 mug/kg) alone (group 3) after failure to respond to standard dose of G-CSF (10 mug/kg) alone. In all groups, an increase in median CD34+ cell yield could be observed following alternative procedures (1.1-to 1.9 x 10(Power6) kg; p = 0.02) The highest increase in CD34+ cell harvest was achieved in group 1 (0.85to2.2 x 10(power6) kg) followedbygroup2(1.2to 1.7)and group 3 (1.0 to 1.4), but without statistically significant difference between the mobilization technologies. All patients with more than 1.0 x 10(power6) CD34+cells/kg in the first apheresis procedure reached the overall target of 2.5 x 10(power6) CD34+ cells/kg after a second or subsequent mobilization procedure. In contrast, only 3 oAf 8 patients (37%) with less than 1.0 x 10(power6) CD34+ cells in the first harvest could reach the target of 2.5 x 10(power6) CD34+ cells after further mobilization attempts.