The addition of plerixafor to granulocyte colony-stimulating factor (G-CSF) treatment after autologous stem cell transplantation may not enhance lymphocyte recovery in patients with multiple myeloma (MM), according to study results published in the American Journal of Hematology.
In this retrospective analysis, patients who had MM had received either G-CSF only (469 patients) or G-CSF with plerixafor (141 patients). G-CSF was given for 5 days, and plerixafor was given only to patients with peripheral blood CD34-positive cell counts below 20 cells/mL on the fifth day of G-CSF administration. The primary study end point was absolute lymphocyte count at day 30 (ALC30) following transplantation.
For patients who received G-CSF with plerixafor, median ALC30 was 1.2 x 109/mL (range, 0.1 x 109 – 5.1 x 109), compared with 1.3 x 109/mL (range, 0.1 x 109 – 4.5 x 109) for patients who received G-CSF only (P =.608). Absolute monocyte count, median time to neutrophil recovery, and median time to platelet recovery were each similar between the treatment groups.
Median progression-free survival (PFS) was 2.77 years (95% CI, 1.99-3.27) for patients receiving G-CSF with plerixafor and 2.46 years (95% CI, 2.14-3.15) for those on G-CSF only (hazard ratio, 1.13; 95% CI, 0.84-1.50; P =.417).
Median overall survival (OS) was shorter for patients who received G-CSF with plerixafor compared with those given G-CSF only (3.73 vs 6.09 years; P =.011). By the time of analysis, fatalities occurred in 25% of patients in each group, and most deaths were attributed to disease-related causes in each group.
“The use of plerixafor for augmentation of stem cell mobilization did not alter the ALC30, contrary to the hypothesis that plerixafor can mobilize more lymphocytes,” wrote the researchers. However, they indicated that the risk-adapted strategy for administration of plerixafor used in this study may aid with PFS for patients who are poor mobilizers.
- Shah H, Kim S, Singh P, et al. Clinical outcomes of multiple myeloma patients who undergo autologous hematopoietic stem cell transplant with G-CSF or G-CSF and plerixafor mobilized grafts [published online November 5, 2019]. Am J Hematol. doi:10.1002/ajh.25672