Plerixafor Plus G‐ CSF Versus Etoposide Combined With Cyclophosphamide and G‐ CSF for Autologous Stem Cell Mobilization in Multiple Myeloma in the E

ABSTRACT

Autologous stem cell transplantation (ASCT) is the standard of care for eligible patients with multiple myeloma (MM). The optimal stem cell mobilization strategy for these patients remains a matter of debate in the era of novel agents. To compare the efficacy and outcomes of peripheral blood stem cells mobilization with plerixafor (PXF) and granulocyte‐colony stimulating factor (G‐CSF) against etoposide combined with cyclophosphamide (EC) plus G‐CSF in MM patients. We included 119 patients with MM who underwent stem cell mobilization in our center, 56 patients received PXF + G‐CSF and 63 received EC + G‐CSF. Propensity score matching between two cohorts at a 1:1 ratio was performed according to baseline characteristics to minimize bias. After propensity matching, 37 versus 37 patients in the PXF + G‐CSF versus EC + G‐CSF cohorts. Compared to patients treated with EC + G‐CSF, the PXF + G‐CSF group was associated with significantly higher median concentration peripheral blood CD34+ cell counts (79 vs. 65.1 cells/μL, p  = 0.038) and higher CD34+ cell yields (9.58 vs. 5.70 × 10 ⁶ /kg, p  = 0.009). All patients in the PXF + G‐CSF group experienced successful mobilization, compared to 72% of patients ( p  = 0.002) in the EC + G‐CSF group. Higher median lymphocyte counts in the stem cell products were observed in the PXF + G‐CSF group compared with the EC + CSF group (241.59 vs. 120.87 × 10 ⁶ /kg, p  = 0.021). Mobilization with PXF + G‐CSF was associated with decreased episodes of neutropenia grade ≥ 4 (13.51% vs. 51.35%, p  = 0.001), lower use of antibiotics ( p  = 0.001), and less need for blood transfusions (RBC: 0 vs. 0 units, p  = 0.021; PLT: 0 vs. 0 units, p  = 0.019). Besides, PXF + G‐CSF leaded to faster neutrophil and platelet engraftment after ASCT (neutrophil: 11 vs. 12 days, p  = 0.034; platelet: 10 vs. 11 days, p  = 0.023). Survival analysis showed that no major differences in PFS and OS were observed between the PXF and EC groups. PXF + G‐CSF is a more effective and less toxic mobilizing agent than the chemotherapy‐based regimen (EC + G‐CSF), and is associated with faster hematopoietic reconstruction without increasing the risk of tumor progression. This regimen may be considered a valuable option for stem cell mobilization.