Optimal chemo-mobilization for the collection of peripheral blood stem cells in patients with multiple myeloma

BackgroundFor successful autologous stem cell transplantation, the collection of a sufficient number of hematopoietic stem cells after induction therapy is essential for transplant candidates with multiple myeloma (MM).MethodsIn this study, we compared the efficacy and safety of stem cell mobilization using cyclophosphamide (CY; 3.0g/m(2) on day 1) or etoposide (VP-16; 375mg/m(2) on days 1 and 2) in patients with MM. Granulocyte-colony stimulating factor (G-CSF, 10g/kg/day, subcutaneously) was administered from the onset of neutropenia to the final day of collection.ResultsSixty-five patients were mobilized with a combination of CY and G-CSF, and 63 were mobilized with a combination of VP-16 and G-CSF. All patients were mobilized within 7months of beginning frontline treatment. The median number of CD34(+) cells collected was significantly higher in the VP-16 mobilization group than in the CY mobilization group (27.6x10(6) CD34(+)/kg vs. 9.6x10(6) CD34(+)/kg, P<0.001). The rate of mobilization failure, defined as <2.0x10(6) CD34(+)/kg collected in three apheresis procedures, was lower in the VP-16 group than in the CY group (1.6% vs. 10.8%, P=0.062). Severe infections during the mobilization period were more frequent in the CY group than in the VP-16 group (18.5% vs. 7.9%, P=0.117).ConclusionIn conclusion, an intermediate dose of VP-16 with G-CSF appears to be an effective and tolerable chemo-mobilization method compared to CY and G-CSF, particularly in cases where use plerixafor in MM is difficult.