Safety and preliminary efficacy of plerixafor (Mozobil) in combination with chemotherapy and G-CSF: an open-label, multicenter, exploratory trial in patients with multiple myeloma and non-Hodgkin's lymphoma undergoing stem cell mobilization.

Plerixafor, a novel CXCR4 inhibitor, is effective in mobilizing PBSCs particularly when used in conjunction with G-CSF. In four cohorts, this pilot study explored the safety of plerixafor mobilization when incorporated into a conventional stem cell mobilization regimen of chemotherapy and G-CSF. Forty (26 multiple myeloma and 14 non-Hodgkin's lymphoma) patients were treated with plerixafor. Plerixafor was well tolerated and its addition to a chemo-mobilization regimen resulted in an increase in the peripheral blood CD34+ cells. The mean rate of increase in the peripheral blood CD34+ cells was 2.8 cells/microl/h pre- and 13.3 cells/microl/h post-plerixafor administration. Engraftment parameters were acceptable after myeloblative chemotherapy, with the median day for neutrophil and plt engraftment being day 11 (range 8-20 days) and day 13 (range 7-77 days), respectively. The data obtained from the analysis of the cohorts suggest that plerixafor can safely be added to chemotherapy-based mobilization regimens and may accelerate the rate of increase in CD34+ cells on the second day of apheresis. Further studies are warranted to evaluate the effect of plerixafor in combination with chemomobilization on stem cell mobilization and collection on the first and subsequent days of apheresis, and its impact on resource utilization.

Mobilization of peripheral blood stem cells for autologous transplant in non-Hodgkin's lymphoma and multiple myeloma patients by plerixafor and G-CSF and detection of tumor cell mobilization by PCR in multiple myeloma patients.

This report describes the first investigational use of plerixafor in Europe and the determination of tumor cell mobilization by polymerase chain-reaction after plerixafor treatment in a subset of patients with multiple myeloma (MM). Thirty-five patients (31 MM and 4 NHL) received granulocyte colony-stimulating factor (G-CSF) (10 microg/kg) each morning for 4 days. Starting the evening of Day 4, patients recieved plerixafor 0.24 mg/kg. Apheresis was initiated 10-11 h later, in the morning of Day 5. This regimen of G-CSF treatment each morning before apheresis and plerixafor treatment in the evening was repeated for up to 5 consecutive days. Mobilization with plerixafor and G-CSF resulted in a median 2.6-fold increase in peripheral blood (PB) CD34+ cell count compared with before plerixafor treatment. All patients collected > or =2 x 10(6) CD34+ cells/kg and 32 of 35 patients collected > or =5 x 10(6) CD34+ cells/kg. After plerixafor treatment, 3 of 7 patients had a small increase and 4 of 7 patients had a small decrease in PB tumor cells. No G-CSF was given post transplant. The median number of days to polymorphonuclear leukocyte and platelet engraftment was 14.0 and 11.0, respectively. There were no reports of graft failure. Plerixafor was generally well tolerated. Mobilization of PB CD34+ cells was consistent with previous clinical trials. The addition of plerixafor did not significantly increase the relative number of PB MM tumor cells.

AMD3100 plus G-CSF can successfully mobilize CD34+ cells from non-Hodgkin's lymphoma, Hodgkin's disease and multiple myeloma patients previously failing mobilization with chemotherapy and/or cytokine treatment: compassionate use data.

AMD3100 given with G-CSF has been shown to mobilize CD34+ cells in non-Hodgkin's lymphoma (NHL), multiple myeloma (MM), and Hodgkin's disease (HD) patients who could not collect sufficient cells for autologous transplant following other mobilization regimens. These poor mobilizers are usually excluded from company-sponsored trials, but have been included in an AMD3100 Single Patient Use protocol, referred to as a Compassionate Use Protocol (CUP). A cohort of 115 data-audited poor mobilizers in CUP was assessed, with the objective being to collect > or =2 x 10(6) CD34+ cells per kg following AMD3100 plus G-CSF mobilization. The rates of successful CD34+ cell collection were similar for patients who previously failed chemotherapy mobilization or cytokine-only mobilization: NHL -- 60.3%, MM -- 71.4% and HD -- 76.5%. Following transplant, median times to neutrophil and PLT engraftment were 11 days and 18 days, respectively. Engraftment was durable. There were no drug-related serious adverse events. Of the adverse events considered related to AMD3100, two (1.6%) were severe (one patient -- headache, one patient -- nightmares). Other AMD3100-related adverse events were mild (84.8%) or moderate (13.6%). The most common AMD3100-related adverse events were gastrointestinal reactions, injection site reactions and paresthesias. AMD3100 plus G-CSF offers a new treatment to collect CD34+ cells for autologous transplant from poor mobilizers, with a high success rate.

A pharmacokinetic-pharmacodynamic model for the mobilization of CD34+ hematopoietic progenitor cells by AMD3100.

BACKGROUND: AMD3100 is a small-molecule CXCR4 antagonist that has been shown to induce the mobilization of CD34 + hematopoietic progenitor cells from bone marrow to peripheral blood. AMD3100 has also been shown to augment the mobilization of CD34 + cells in cancer patients when administered in combination with granulocyte colony-stimulating factor (G-CSF) (filgrastim). The purpose of this study was to characterize the exposure-response relationship of AMD3100 in mobilizing CD34 + cells when administered as a single agent in healthy volunteers. METHODS: AMD3100 concentrations and CD34 + cell counts obtained from 29 healthy subjects in a single-dose, intensively sampled pharmacokinetic/pharmacodynamic (PK-PD) study were analyzed by use of nonlinear mixed effects regression with the software NONMEM. FOCE (first order conditional estimation) with interaction was the estimation method, and simultaneous PK-PD fitting was adopted. RESULTS: The pharmacokinetics of AMD3100 was described by a 2-compartment model with first-order absorption. The population estimates (+/-SE) for clearance and central volume of distribution were 5.17 +/- 0.49 L/h and 16.9 +/- 3.79 L, respectively. CD34 + cell mobilization was best described by an indirect effect model that stimulates the entry process of CD34 + from bone marrow to peripheral blood in the form of a sigmoid maximum effect model. The population estimates (+/-SE) of maximum effect, concentration causing 50% of maximum response, and equilibration time were 12.6 +/- 4.89, 53.6 +/- 11.9 mug/L, and 5.37 +/- 1.31 hours, respectively. CONCLUSIONS: This study characterizes the exposure-response relationship of AMD3100 in mobilizing CD34 + cells after subcutaneous administration. This PK-PD model will be useful in assessing relevant covariates and for optimizing the use of AMD3100 in various patient populations.