The use of plerixafor in selected high-risk patients and poor mobilizers did not increase the total charges associated with stem cell collection when compared with poor mobilizers treated with G-CSF alone. The targeted use of plerixafor increased the overall success rate of mobilizing a minimum number of CD34+ cells from 93% to 98% in patients with hematologic malignancies scheduled for autotransplant and increased the overall charges associated with stem cell collection in all patients by an average of 17%.

Plerixafor with granulocyte colony-stimulating factor (G-CSF) is effective for hematopoietic stem cell (HSC) mobilization in patients with non-Hodgkin Lymphoma and myeloma; however, labeling requires dosing 11 hours before apheresis. Pharmacodynamic studies show peak blood CD34(+) cell counts at 10 to 14 hours; limited data are available for later time points. To address the effect of afternoon plerixafor dosing on CD34(+) cell yields, we conducted a prospective clinical trial in myeloma patients undergoing stem cell collection. Thirty-one patients received plerixafor 17 hours before apheresis; blood CD34(+) cells were measured before the first plerixafor dose and 1, 3, and 17 ± 1 hours after treatment. The target HSC number (≥10 × 106 CD34(+) cells/kg) was collected from 22 subjects (73%) in 1 day and from all subjects within 3 days. Hematopoietic engraftment after transplantation and adverse events were similar to previous studies. Plerixafor given 17 hours before apheresis yields desired HSC collection efficiencies after induction treatment in myeloma patients.

BACKGROUND One proposed mechanism of extracorporeal photopheresis (ECP) in reducing chronic graft-versus-host disease (cGVHD) is alteration in numbers of circulating dendritic cells (DCs). This hypothesis was tested by correlating numbers of DC precursors and T cells in the blood before and during ECP therapy with response of cGVHD. STUDY DESIGN AND METHODS Twenty-five patients with cGVHD were treated with ECP. Data were collected with emphasis on blood cellular markers, clinical response to ECP, and overall survival. RESULTS Fourteen patients (56%) responded and had better 2-year survival than nonresponders (88% vs. 18%, p = 0.003). Responders had higher baseline circulating myeloid DC (mDC) and plasmacytoid DC precursors and CD4+ and CD8+ T cells compared with nonresponders. Receiver operating characteristic curve analyses showed that the best baseline cutoff values to predict response to ECP were mDC counts of 3.7 cells/µL (79% sensitivity, 82% specificity) and CD4+ T-cell counts of 104 cells/µL (71% sensitivity, 82% specificity). CD4+ T cells declined in responders over time, but not in nonresponders, and no significant changes were seen in CD8 T-cell or DC numbers over a 12-month period in responder or nonresponder groups. CONCLUSIONS Higher baseline numbers of circulating DCs and T cells may predict clinical response to ECP in patients with cGVHD.

Background To investigate whether granulocyte colony stimulating factor (G-CSF) injection in lower adipose-tissue-containing sites (arms and legs) would result in a lower exposure and reduced stem cell collection efficiency compared with injection into abdominal skin. Study Design and Methods We completed a prospective randomized study to determine the efficacy and tolerability of different injection sites for patients with multiple myeloma or lymphoma undergoing stem cell mobilization and apheresis. Primary end-points were the number of CD34+ cells collected and the number of days of apheresis. Forty patients were randomized to receive cytokine injections in their abdomen (group A) or extremities (group B). Randomization was stratified based upon diagnosis (myeloma; N=29 vs. lymphoma; N=11), age, and mobilization strategy, and balanced across demographic factors and body mass index. Results 35 subjects were evaluable for the primary end-point: 18 in group A and 17 in group B. One evaluable subject in each group failed to collect a minimum dose of at least 2.0 × 106 CD34+ cells/kg. The mean numbers of CD34+ cells (±SD) collected were not different between groups A and B (9.15 ± 4.7 × 106/kg versus 9.85 ± 5 × 106/kg, respectively; p=NS) following a median of 2 days apheresis. Adverse events were not different between the two groups. Conclusion The site of G-CSF administration does not affect the number of CD34+ cells collected by apheresis or the duration of apheresis needed to reach the target cell dose.