PB2195: MOBILIZATION WITH CYTARABINE AND GRANULOCYTE COLONY STIMULATING FACTOR (G-CSF) GIVES BETTER YIELD THAN MOBILIZATION WITH G-CSF ALONE OR COMBINED WITH CYCLOPHOSPHAMIDE

Abstract

Background: Patients with multiple myeloma are poor mobilizers and often require multiple cytapheresis procedures. Most popular mobilization regimens are with G-CSF given as a sole treatment or in combination with cyclophosphamide. Recently, several reports indicated that higher yields could be obtained following chemomobilization with cytarabine and G-CSF. Aims: Our aim was to compate the effectiveness of chemomobilization with cytarabine and G-CSF with the other regimens which we have used. Methods: Patients received 2x400mg/m2 cytarabine for two days, followed by 5mcg/kg G-CSF two days after for at least nine days. Cytapheresis was initiated with WBC count above 5x109/L, PLT count above 30x109/L and CD34+ cell count above 20/µl. Results of this group of patients were compared with results from a historic group of myeloma patients harvested between 2018 and 2020. Results: The new regimen showed markedly higher initial counts of CD34+ cells resulting in significantly better average yields (12.6x10^6/kg for the cytarabine + G-CSF group; 3.98 x10^6/kg for the G-CSF group and 4.998 x10^6/kg for the Cyclophosphamide+ G-CSF group). Summary/Conclusion: Compared with other hematological malignancies, patients with multiple myeloma are hard to mobilize for collection of sufficient CD34+ cells. Possible explanations are advanced age and bone marrow involvement. Chemomobilization with cytarabine and G-CSF seem to overcome poor mobilization and collection yields for this patient group.