Plerixafor in combination with granulocyte-colony-stimulating factor after chemotherapy increases mobilization efficiency in patients with lymphoma or myeloma: results of a Phase II clinical trial

Abstract

Background: We tested whether adding plerixafor to G-CSF mobilization after chemotherapy would increase the proportion of patients collecting the target number of CD34+ cells/kg in 1 day of apheresis to >75%.

Study design and methods: Autologous stem cell transplant-anticipated multiple myeloma or lymphoma patients were eligible. Patients were mobilized with cyclophosphamide (n=17); DCEP (n=1); R-ICE (n=20); CHOP (n=2); or R-HCVAD (n=5) and given 5 mg/kg/day GCSF starting on Day 2 and increasing to 10 mg/kg/day on Day 6. Plerixafor 240 mg/kg was injected subcutaneously on the day the neutrophil count was more than 1.5 × 10(9) cells/L with apheresis the folllowing day. G-CSF, plerixafor, and apheresis continued daily until 5 × 10(6) (lymphoma) or 10 × 10(6) (myeloma) CD34+ cells/kg were collected.

Results: Seventeen myeloma and 28 lymphoma patients enrolled, and 76% collected the target number of CD34+ cells in 1 day. Twelve subjects with median CD34+ counts of 142 × 10(6) cells/L began apheresis without plerixafor and collected 20 × 10(6) CD34+ cells/kg in 1 day. The remaining 33 subjects, with median 11.7 × 10(6) CD34+ cells/L and 5.4 × 10(9) WBC/L, received plerixafor. Plerixafor-treated subjects collected 7.8 × 10(6) CD34+ cells/kg; 22 (67%) collected in 1 day, while 11 (33%) required more than 1 day. Plerixafor was well tolerated, with no serious adverse events.

Conclusions: Plerixafor administration after chemotherapy for autologous stem cell mobilization is feasible, well tolerated, and increases the proportion of subjects collected in a single day compared to mobilization with G-CSF after chemotherapy.