Stem Cell Mobilization in Multiple Myeloma: Comparing Safety and Efficacy of Cyclophosphamide plus /- Plerixafor versus Granulocyte Colony-Stimulating Factor plus /- Plerixafor in the Lenalidomide Era

Growth factor and chemotherapy-based stem cell mobilization strategies are commonly used to treat patients with multiple myeloma. We retrospectively compared 398 patients mobilized between 2017 and 2020 using either cyclophosphamide (4 g/m(2)) plus granulocyte colony-stimulating factor (G-CSF) or G-CSF alone, with on demand plerixafor (PXF) in both groups. Although total CD34(+ )yield was higher after chemomobilization compared with G-CSF +/- PXF (median, 13.6 x 10(6)/kg versus 4.4 x 10(6)/kg; P < .01), achievement of >= 2 x 10(6) CD34(+) cells (95% versus 93.7%; P = .61) and rates of mobilization failure (5% versus 6.3%; P = .61) were similar. Fewer patients required PXF with chemomobilization (12.3% versus 49.5%; P < .01), and apheresis sessions were fewer (median, 1 [range, 1 to 4] versus 2 [range, 1 to 5]). The rate of complications, including neutropenic fever, emergency department visits, and hospitalizations, was higher after chemomobilization (30% versus 7.4%; P < .01). Previous use of <= 6 cycles of lenalidomide did not impair cell yield in either group. The median cost of mobilization was 17.4% lower in the G-CSF +/- PXF group (P = .01). Between group differences in time to engraftment were not clinically significant. Given similar rates of successful mobilization, similar engraftment time, and less toxicity and lower costs compared with chemomobilization, G-CSF with on-demand PXF may be preferable in myeloma patients with adequate disease control and limited lenalidomide exposure. (C) 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.