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

Background and objective: 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.

Materials and methods: 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.

Results: 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).

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