Mobilization of Autologous Peripheral Blood Stem Cells (PBSC) in CD20+ Lymphoma Patients Using RICE, Granulocyte-Colony Stimulating Factor (G-CSF) and Plerixafor

Abstract

RICE is salvage therapy for treating CD20+non-Hodgkin lymphoma (NHL). It is combined with G-CSF to collect autologous peripheral blood stem cells (aPBSC). Little data exists, though, on the combination of G-CSF and Plerixafor after RICE in mobilizing adequate number of CD34 cells and the product’s immune content. We report on the results of twenty CD20+ NHL patients after RICE, G-CSF and Plerixafor were given to collect aPBSC. The median number of cells collected was 12.92 × 10<sup>6</sup> CD34 cells/kg (range 5.44-83.76). Plerixafor toxicity included diarrhea (n = 5) and injection-site irritation (n = 1). Seventeen patients collected; fifteen patients did so in one session. Two patients with CLL/Richter or transformed follicular had positive-flow products. Addition of Plerixafor to G-CSF increased by 2.6-9 folds the number of blood CD34 cells. Sixteen patients went to ASCT, with a median of 7.29 × 10<sup>6</sup> CD34 cells/kg infused. The median engraftment time post-ASCT for neutrophils was 12 (range 10-19), for platelets ≥20K 11 (range 0-19) and ≥50K 16.5 (range 11-42) days. There were no graft failures. In APBSC product, there was no evidence of NK or LAK lytic activity (n = 10), only LAK activity (n = 4) and both LAK and NK activity (n = 2). Blood NK activity was common on day +28 post-ASCT. There was no significant correlation between apheresis product and the number of blood immune cells post- ASCT or relapse. Addition of Plerixafor to RICE/G-CSF is well tolerated. The majority of patients collected aPBSC in one session.