Cost and Clinical Analysis of Autologous Hematopoietic Stem Cell Mobilization with G-CSF and Plerixafor Compared to G-CSF and Cyclophosphamide

Plerixafor plus granulocyte-colony stimulating factor (G-CSF) has been shown to mobilize more CD34⁺ cells than G-CSF alone for autologous hematopoietic stem cell transplantation (HSCT). However, many centers use chemotherapy followed by G-CSF to mobilize CD34⁺ cells prior to HSCT. We performed a retrospective study of patients who participated in the expanded access program (EAP) of plerixafor and G-CSF for initial mobilization of CD34⁺ cells, and compared outcomes to matched historic controls mobilized with cyclophosphamide 3-5 g/m² and G-CSF at 2 centers that participated in the EAP Control patients were matched for age, sex, disease, disease stage, and number of prior therapies. Mobilization costs were defined to be the costs of medical procedures, resource utilization, and medications. Median national CMS reimbursement rates were used to establish the costs of procedures, hospitalization, provider visits, apheresis, CD34⁺ cell processing and cryopreservation. Average sale price was used for G-CSF, plerixafor, cyclophosphamide, MESNA, antiemetics, and antimicrobials. A total of 33 patients from the EAP and 33 matched controls were studied. Two patients in the control group were hospitalized for neutropenic fever during the mobilization period. Apheresis started on the scheduled day in 33 (100%) study patients and in 29 (88%) control patients (P = 0.04). Sixteen (48%) control patients required weekend apheresis. There was no difference in number of CD34⁺ cells collected between the groups, and all patients proceeded to HSCT with no difference in engraftment outcomes. Median total cost of mobilization was not different between the plerixafor/G-CSF and control groups ($14,224 versus $18,824; P = .45). In conclusion, plerixafor/G-CSF and cyclophosphamide/G-CSF for upfront mobilization of CD34⁻ cells resulted in similar numbers of cells collected, costs of mobilization, and clinical outcomes. Additionally, plerixafor/G-CSF mobilization resulted in more predictable days of collection, no weekend apheresis procedures, and no unscheduled hospital admissions.

Key Words: Plerixafor, Mobilization, Cost analysis, Autologous transplant