Plerixafor to rescue failing chemotherapy-based stem cell mobilization: it’s not too late

Abstract

Plerixafor can rescue the outcome of failing chemotherapy-based stem cell mobilization. However, the optimal time for plerixafor injection in this setting has not been determined. This was investigated by retrospective analysis of data from 48 mobilizations with plerixafor, chemotherapy, and granulocyte-colony stimulating factor (G-CSF). The required yield of 2.0×10⁶ CD34+ cells/kg was collected from 71% of patients; the median total yield was 4.1 × 10⁶ CD34+ cells/kg. Patients to whom plerixafor was administered late (≥15 days) after chemotherapy, after a long duration (≥13 days) of treatment with G-CSF, or when the white blood cell count was high (≥20 × 10⁹/L) were mobilized as efficiently as other patients. Plerixafor was shown to rescue mobilizations at a comparable rate in patients with critically low levels of peripheral blood CD34+ cells (<3/µL) and those with higher concentrations. These data suggest that late administration of plerixafor in the course of chemotherapy-based mobilization does not contribute to the failure of this strategy.

Keywords:

• Stem cell mobilization
• plerixafor
• autologous stem cell transplantation
• G-CSF

Acknowledgements

The authors would like to acknowledge sincerely the manufacturer of plerixafor—Genzyme—for providing plerixafor free of charge within the CUP, as well as for the facilitation of data collection. Genzyme did not participate in the study design, analysis, and interpretation of data, in the writing of the report, or in the decision to submit the paper for publication. We would like to thank all the physicians who used plerixafor within the CUP and contributed data from their patients.

Potential conflict of interest:

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