Efficacy and safety of plerixafor for the mobilization/collection of peripheral hematopoietic stem cells for autologous transplantation in Japanese patients with multiple myeloma.

To evaluate the efficacy and safety of plerixafor for the mobilization/collection of peripheral hematopoietic stem cells (HSCs) for autologous transplantation in Japanese patients with multiple myeloma (MM). In a randomized study, patients received G-CSF (filgrastim, 400 µg/m2 /day) for 4 days prior to the first dose of plerixafor. Starting on Day 4 evening and for up to 4 days, patients received either plerixafor (240 µg/kg/day) + G-CSF group (PG group) or G-CSF alone (G group). Daily apheresis started on Day 5 for up to 4 days, or until ≥6 × 106 CD34+ cells/kg were collected. A total of 7 patients were randomized in each treatment group. Five patients in PG group and no patients in G group achieved a collection of ≥6 × 106 CD34+ cells/kg in ≤2 days of apheresis [difference of 71.4% (90%CI 29-100%)]. These results were supported by the shorter median time to collect ≥6 × 106 CD34+ cells/kg (2 days in PG group; no patient in G group). The incidence of treatment emergent adverse events (TEAEs) was higher in PG group than in G group. Plerixafor was well tolerated, and effective for the mobilization/collection of peripheral HSCs for autologous transplantation in Japanese patients with MM.