Factors affecting successful mobilization with plerixafor: an Italian prospective survey in 215 patients with multiple myeloma and lymphoma.

Background: Although the efficacy of plerixafor in peripheral blood stem cell (PBSC) mobilization has been explored in several studies, factors associated with successful plerixafor mobilization after administration of granulocyte-colony-stimulating factor (G-CSF), with or without chemotherapy, have not been investigated. We analyzed data on PBSC mobilization from a large Italian database of lymphoma and myeloma plerixafor-treated patients.
Study Design and Methods: Two endpoints were established to define successful mobilization: patients with at least 2 × 10(6) CD34+ cells/kg collected by three leukapheresis procedures and patients achieving a peak count of at least 20 × 10(6) CD34+ cells/L during mobilization.
Results: Plerixafor achieved successful mobilization in both predicted (n = 64) and proven poor mobilizers (PMs; n = 143), classified according to the Gruppo Italiano Trapianto di Midollo Osseo (GITMO) criteria. Successful mobilization was independent of type of mobilization (steady state or chemotherapy); age; sex; disease; number or type of chemotherapy regimens preceding plerixafor; radiation therapy; prior treatment with melphalan, carmustine, lenalidomide, and radioimmune conjugates; and laboratory variables. Multivariate analysis identified previous fludarabine treatment and premobilization platelet count as predictors of successful mobilization.
Conclusion: This large, prospective, nationwide study confirmed plerixafor efficacy for mobilizing PBSCs when added to G-CSF with or without chemotherapy. Plerixafor can overcome negative effects of most predictors of poor mobilization to achieve satisfactory harvest both in predicted and proven PM.
(© 2013 American Association of Blood Banks.)