Upfront use of plerixafor and granulocyte-colony stimulating factor (GCSF) for stem cell mobilization in patients with multiple myeloma: efficacy and analysis of risk factors associated with poor stem cell collection efficiency*

Abstract

Plerixafor (P), an agent that selectively and reversibly binds to the chemokine receptor CXCR4, has been approved in combination with G-CSF (P + G-CSF) for stem cell (SC) mobilization in patients with multiple myeloma (MM). The goal of this study was to determine the SC collection success rate of P + G-CSF using a clinically relevant outcome defined as the ability to collect at least 5 × 106 CD34+ cells/kg to allow safely two transplants, and identify risk factors impacting SC mobilization. One hundred and thirty-eight patients were mobilized with P + G-CSF upfront following induction. The SC collection success rate was 92.8%. We identified exposure to lenalidomide alone (p = .038), WBC count <4 × 103/mcL prior to mobilization (p = .01) and non-African American race (p = .019), as risk factors for low efficiency by multivariate analysis. This study demonstrates that P + G-CSF is highly efficient in MM patients and provides strong support for its upfront use in SC collection for MM patients.