Booster of plerixafor can be successfully used in addition to chemotherapy-based regimen to rescue stem cell mobilization failure.

Background: Autologous stem cell transplantation (autoSCT) is currently considered one of the standard approaches in the treatment of patients suffering from multiple myeloma and recurrent or relapsed lymphomas. Unfortunately, a significant proportion of those patients fail to mobilize minimum CD34+ cell dose to undergo this procedure. Here we present the strategy that allows to rescue the outcome of ongoing unsuccessful chemotherapy based mobilizations.

Case Report: All five patients failed to release satisfactory number of CD34+ cells to peripheral blood after chemotherapy plus G-CSF-based mobilization regimen, despite raise in leukocytosis. In this situation, we decided to administer a booster of plerixafor, a specific CXCR4 receptor inhibitor. We observed rapid 2.6 to 16-fold increase of peripheral blood CD34+ cells number that allowed to start aphereses in all cases. Consequently, all five patients who would not otherwise collect required number of CD34+ cells, collected above 2.0×106 CD34+ cells/kg that allowed for hematopoietic stem cell transplantation.

Conclusions: We would like to suggest that poor mobilizers could be rescued with the timely addition of plerixafor, thus they can avoid another procedure of stem cell mobilization.