Plerixafor for autologous peripheral blood stem cell mobilization in patients previously treated with fludarabine or lenalidomide.

Fludarabine and lenalidomide are essential drugs in the front-line treatment of non-Hodgkin lymphoma (NHL) and multiple myeloma (MM), respectively. Data suggests that fludarabine and lenalidomide therapy may have a deleterious effect on stem cell mobilization. In the European compassionate use program, 48 patients (median age 57 years) previously treated with fludarabine (median 5 cycles; range: 1-7 cycles) were given plerixafor plus granulocyte colony-stimulating factor (G-CSF) for remobilization following a primary mobilization attempt. The overall median number of CD34+ cells collected was 2.3 × 10(6)/kg (range: 0.3-13.4). The minimum required number of CD34+ cells (≥2.0 × 10(6)/kg) was collected from 58% of patients in a median of 2 days. Thirty-five patients (median age = 57 years) previously treated with lenalidomide (median 5 cycles; range: 1-10 cycles) were given plerixafor plus G-CSF for remobilization. The overall median number of CD34+ cells collected was 3.4 × 10(6)/kg (range: 1.1-14.8). The minimum required number of CD34+ cells (≥2.0 × 10(6) per kg) was collected from 69% of patients in a median of 2 days. In conclusion, salvage mobilization with plerixafor plus G-CSF is successful in the majority of patients with MM previously treated with lenalidomide. In fludarabine-exposed patients, only 58% of patients will achieve successful salvage mobilization with plerixafor plus G-CSF, suggesting the need for novel mobilization regimens algorithms in this subgroup of patients

Plerixafor to rescue failing chemotherapy-based stem cell mobilization: it's not too late

Plerixafor can rescue the outcome of failing chemotherapy-based stem cell mobilization. However, the optimal time for plerixafor injection in this setting has not been determined. This was investigated by retrospective analysis of data from 48 mobilizations with plerixafor, chemotherapy, and granulocyte-colony stimulating factor (G-CSF). The required yield of 2.0 x 10(6) CD34+ cells/kg was collected from 71% of patients; the median total yield was 4.1 x 10(6) CD34+ cells/kg. Patients to whom plerixafor was administered late (>= 15 days) after chemotherapy, after a long duration (>= 13 days) of treatment with G-CSF, or when the white blood cell count was high (>= 20 x 10(9)/L) were mobilized as efficiently as other patients. Plerixafor was shown to rescue mobilizations at a comparable rate in patients with critically low levels of peripheral blood CD34+ cells (53/mL) and those with higher concentrations. These data suggest that late administration of plerixafor in the course of chemotherapy-based mobilization does not contribute to the failure of this strategy

European data on stem cell mobilization with plerixafor in patients with nonhematologic diseases: an analysis of the European consortium of stem cell mobilization

BACKGROUND: Plerixafor with granulocytecolony-stimulating factor (G-CSF) has been shown to enhance stem cell mobilization in patients with multiple myeloma and lymphoma with previous mobilization failure. In this European named patient program we report the experience in insufficiently mobilizing patients diagnosed with nonhematologic diseases. STUDY DESIGN AND METHODS: Thirty-three patients with germ cell tumor (n = 11), Ewing sarcoma (n = 6), Wiscott-Aldrich disease (n = 5), neuroblastoma (n = 4), and other nonhematologic diseases (n = 7) were included in the study. Plerixafor was limited to patients with previous or current stem cell mobilization failure and given after 4 days of G-CSF (n = 21) or after chemotherapy and G-CSF (n = 12) in patients who mobilized poorly. RESULTS: Overall, 28 (85%) patients succeeded in collecting at least 2 x 106/kg body weight (b.w.) CD34+ cells (median, 5.0 x 106/kg b.w. CD34+ cells; range, 2.0 x 106-29.5 x 106/kg b.w. CD34+ cells), and five (15%) patients collected a median of 1.5 x 106/kg b.w. CD34+ cells (range, 0.9 x 106-1.8 x 106/kg b.w. CD34+ cells). Nineteen patients proceeded to transplantation. The median dose of CD34+ cells infused was 3.3 x 106/kg b.w. (range, 2.3 x 106-6.7 x 106/kg b.w. CD34+ cells). The median numbers of days to neutrophil and platelet engraftment were 11 (range, 9-12) and 15 (range, 10-25) days, respectively. CONCLUSION: These data emphasize the role of plerixafor in combination with G-CSF or chemotherapy and G-CSF as an effective mobilization regimen with the potential of successful stem cell collection. Accordingly, plerixafor seems to be safe and effective in patients with nonhematologic diseases. Larger prospective studies are warranted to further assess its use in these patients