(PA-108) A Comparison of Chemo-free Strategy with Plerixafor Plus G-CSF versus High-dose Cyclophosphamide Plus G-CSF as First-line PBSC Mobilization in Multiple Myeloma Patients: A Chinese Explorative Study

Plerixafor plus G-CSF (PLE+G-CSF) has demonstrated superior mobilization efficacy compared to cyclophosphamide plus G-CSF (CY+G-CSF) in multiple myeloma (MM) patients. However, the use of two or more vials of plerixafor to achieve sufficient stem cell mobilization may be financially prohibitive for some patients. This study aims to explore a more efficient and cost-effective mobilization scheme by using only one vial of plerixafor throughout the entire mobilization process.

Methods:   

A retrospective analysis was conducted on 220 MM patients who underwent hematopoietic stem cell mobilization using either PLE+G-CSF (n=98) or CY+G-CSF (n=122) prior to ASCT at our center. In our protocol, a single preparation of plerixafor was used, with the first injection delivering a sufficient dose and the remainder administered during the second injection for steady-state mobilization. The mobilization efficiency, adverse events, average total cost of mobilization, and hematopoietic reconstruction post transplantation were analyzed and compared between the two groups.

Results:   

The plerixafor mobilization strategy significantly improved the success rate of mobilization (85.7% vs. 74.6%, P=0.042) and reduced the time of apheresis (1 (1, 2) d vs. 2 (1, 3) d, P < 0.001) compared to the CY group. Additionally, PLE mobilization decreased the need for salvage mobilization and antibiotic use. There was no significant difference in the time to hematopoietic reconstruction between the two groups. Multivariate logistic regression identified three favorable predictors for successful stem cell collection: baseline absolute platelet count ≥ 204 × 10⁹/L (OR 1.01, 95% CI: 1-1.02, P=0.013), day -1 peripheral blood CD34+ cell count ≥ 11 /μL (OR 1.07, 95% CI: 1.03-1.12, P < 0.001), and the use of PLE+G-CSF mobilization (OR 7.61, 95% CI: 1.57-58.32, P=0.025).

Conclusions:   

This study demonstrates that the PLE+G-CSF strategy, even when utilizing only one vial of plerixafor, achieves a higher mobilization success rate, requires fewer apheresis time, and results in fewer adverse events compared to the CY+G-CSF strategy. Furthermore, this approach partially alleviates the financial burden on patients. Factors associated with successful stem cell collection include absolute platelet count ≥ 204 × 10⁹/L at baseline, day -1 PBCD34 ≥11 /μL, and PLE+G-CSF mobilization.