Filgrastim alone versus cyclophosphamide and filgrastim for mobilization in multiple myeloma patients

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is standard treatment approach in most multiple myeloma (MM) patients. Before ASCT, chemomobilization or only granulocyte-colony stimulating factor (G-CSF) mobilization can be preferred in stem cell mobilization. The primary aim of the study is to compare the effect of the two mobilization regimens on hematopoietic engraftment times, CD34+cell counts and number of apheresis required to harvest stem cells.

The records of MM patients who applied to our hospital between 2010 and 2020 were analysed retrospectively. Patients were divided into two groups (Group A: Cyclophosphamide plus filgrastim, Group B: Filgrastim alone) according to the mobilization regimen.

A total of 223 MM patients were included in this study (Group A:153, Group B:70 patients). When the patients in Group A and Group B were compared, the number of collected CD34+ cells were higher in Group A (p < 0.001). However, there was no significant difference between the two groups in terms of median times to neutrophil and platelet engraftment, and number of apheresis required to harvest stem cells (p > 0.05). The rate of infection development during mobilization in the patients in group A and the duration of hospitalization of these patients were higher than the patients in group B (p < 0.001). Patients receiving >6 cycles of chemotherapy and immunomodulatory treatment had lower collected CD34+ cells than other patients (p = 0.012 and p = 0.054).

Based on our findings, filgrastim alone seems to provide a sufficient amount of stem cells in MM patients.