Analysis of remobilization success in patients undergoing autologous stem cell transplants who fail an initial mobilization: risk factors, cytokine use and cost

Inadequate stem cell mobilization is seen in approximately 25% of patients undergoing autotransplantation for hematologic malignancies. Remobilization strategies include chemotherapy/cytokine combinations or high-dose cytokines alone or in combination. From 1/1997 to 7/2002, we remobilized 86 patients who failed an initial mobilization (median total CD34 = 0.72 x 10(6)/kg) in sequential cohorts using high-dose G-CSF (32 mug/kg/day) or G-CSF (10 mug/kg/day) + GM-CSF (5 mug/kg/day). No difference in CD34/kg yields were seen (G-CSF alone: 2.2 x 10(6) and G-CSF + GM-CSF 1.6 x 10(6)) in the median 3 aphereses performed (P = 0.333). Of the 86, 23 (27%) failed the second mobilization; 14 were remobilized again (yield = 1.5 x 10(6) CD34/kg; three aphereses). Of the 86, 93% went to transplant: three progressed, and three had inadequate stem cells. Significant risk factors for a failed remobilization were: number of stem-cell-damaging regimens (P = 0.015), time between last chemotherapy and first mobilization (P = 0.028), and higher WBC at initiation of first mobilization (P = 0.04). High-dose G-CSF (32 mug/kg/day) was more costly @ $9,016, vs $5,907 for the G-CSF + GM-CSF combination (P < 0.001). Most patients failing an initial mobilization benefit from a cytokine only remobilization. Lower cost G-CSF + GM-CSF is as effective as high-dose G-CSF.