Peripheral blood stem cell (PBSC) mobilization and transplantation after fludarabine therapy in chronic lymphocytic leukaemia (CLL): a report of the European Blood and Marrow Transplantation (EBMT) CLL subcommittee on behalf of the EBMT Chronic Leukaemias Working Party (CLWP)

We performed a survey from 122 centres of the European Group of Blood and Marrow Transplantation (EBMT) concerning peripheral blood stem cell (PBSC) mobilization after fludarabine treatment of patients with chronic lymphocytic leukaemia (CLL). A total of 101 leucaphereses from 29 patients was performed. The median cell numbers collected were: CD34+ cells, 2.2 x 106/kg (0.1-15.3); granulocyte-macrophage colony-forming units (GM-CFU), 4.29 x 104/kg (0.4-177); and mononuclear cells, 6.4 x 108/kg (1.3-63). In univariate and multivariate analyses, the numbers of cells collected were not significantly influenced by the nature of mobilizing regimen and there was a trend towards the collection of a higher number of CD34+ cells from patients who received fludarabine only before mobilization. There was a significant correlation between the median number of CD34+ cells collected and the number of courses of fludarabine (higher CD34+ cell numbers were related to more than six courses) and the interval between the last dose of fludarabine and the start of mobilizing therapy (higher CD34+ cell numbers were related to a delay > or = 2 months). Sixteen patients have subsequently undergone autologous transplantation and showed rapid engraftment. In conclusion, the results reported favour early stem cell mobilization in CLL patients who are in remission after first-line therapy. However, attention should be given to the timing of mobilization with respect to the time since the last dose of fludarabine.     

Impact of frontline fludarabine and cyclophosphamide combined treatment on peripheral blood stem cell mobilization in B-cell chronic lymphocytic leukemia

Ongoing studies in B-cell chronic lymphocytic leukemia are evaluating autologous peripheral blood stem cell (PBSC) transplantation in first remission following fludarabine therapy. However, fludarabine could impair PBSC harvest. In 38 patients after frontline oral fludarabine and cyclophosphamide (FDR-CY) therapy, we prospectively evaluated steady state filgrastim- or lenograstim-primed PBSC mobilization to collect 2.0 x 106/kg or more CD34 cells. The first mobilization, performed a median of 178 days (range, 69-377 days) from the last FDR-CY course, was unsuccessful in 32 patients. This result was significantly associated with a low platelet count before mobilization but not with age, interval from last FDR-CY course, initial stage, remission status, or other blood parameters. Finally, after 1, 2, and 3 mobilizations in 27, 10, and 1 patients, 2.0 x 106/kg or more CD34 cells were collected in only 12. Explorations of the mechanism of poor mobilization and adaptation of PBSC harvest policies after fludarabine treatment are therefore warranted.     

Blood stem cell mobilization and collection in patients with chronic lymphocytic leukaemia: a nationwide analysis

Some reports suggest that blood stem cell mobilization is difficult in a proportion of patients with CLL. We evaluated this issue in a large cohort of CLL patients. One hundred and twenty-eight patients with CLL underwent blood stem cell mobilization during 1995-2005 in Finland. Ninety-five percent of the patients had received fludarabine. The most common mobilization regimen was intermediate-dose CY plus G-CSF (90 patients, 70%). At least 2 x 10(6)/kg CD34+ cells were collected after the first mobilization attempt in 83 patients (65%), whereas 45 patients (35%) failed to reach this collection target. No differences were observed between these patient groups with regard to age, time from the diagnosis to mobilization, number of previous treatment lines, number of fludarabine courses, time from the last fludarabine-containing chemotherapy to mobilization, disease status or degree of marrow infiltration. Patients who failed collection had platelets <100 x 10(9)/l more commonly at the time of mobilization (30 vs 4%, P<0.001). A significant proportion of patients with CLL were difficult to mobilize. Adequate marrow function including platelet counts >100 x 10(9)/l seem to be important factors in terms of successful blood stem cell collection.     

Evaluation of marrow and blood haemopoietic progenitors in chronic lymphocytic leukaemia before and after chemotherapy

Abstract: We have evaluated the number and differentiation pattern of CD34+ cells, as well as the CFU–GM, BFU–E and CFU–GEMM progenitors from the blood (PB) and marrow (BM) of 53 chronic lymphocytic leukaemia (CLL) patients. Twenty-four patients were untreated and 29 were studied at 2 months from the last course of fludarabine or chlorambucil; 6 patients, studied after fludarabine therapy, were further evaluated after mobilization with cyclophosphamide and G–CSF. PB of untreated patients showed a median number of CD34+ cells, CFU–GM, BFU–E and CFU–GEMM/10⁵ seeded cells and per litre of PB similar to those of normal controls. No differences were also found in the number of clonogenic progenitors/10⁵ cells in patients studied before and after therapy, while significantly fewer BFU–E/l of PB were found after fludarabine. The number of circulating CD34+ cells/l of PB was significantly lower in patients treated with fludarabine or chlorambucil compared to untreated patients. BM growth was significantly reduced in untreated CLL patients compared to healthy donors. Treatment with fludarabine or chlorambucil restored BM progenitors at levels similar to those of normal controls; this effect did not occur for CFU–GM in patients treated with fludarabine. Three-colour fluorescence analysis demonstrated a differentiation pattern of CD34+ cells, with a greater expression of CD13 and CD33 after treatment with fludarabine compared to untreated patients and normal controls. In 4 patients previously treated with fludarabine who underwent a successful cyclophosphamide and G-CSF mobilization therapy, 4 × 10⁶ CD34+ cells/kg were collected. These 4 patients showed a notable increase of CD34+ cells and of clonogenic cells in the PB, but a marked decrease of BM progenitor cells. The 2 patients who failed CD34+ cell mobilization had a reduced CFU-GM growth both in the PB and in the BM. Taken together, these studies indicate that residual haemopoietic progenitors are present in untreated CLL patients and that stem cell mobilization and collection can be carried out following fludarabine treatment.     

G-CSF Primed Autologous Marrow Harvest and Transplantation in Cytapheresis "Mobilization Failure" Patients: A Descriptive Analysis; Bone Marrow Transplantation

Fifteen cancer patients, deemed blood HSC "mobilization failures" due to CD34 + cell yields of < 0.5 x 10(6) /kg from two consecutive daily cytaphereses, underwent G-CSF primed autologous bone marrow harvest in an attempt to obtain adequate hematopoietic support for subsequent autotransplantation. CD34 + cell yields from the primed marrow harvest were variable; however, some patients had > 5-fold increases in CD34 + cell yields in the marrow compared to cytapheresis, and 4 patients had CD34 + cell yields of > 1.0 (i.e., 1.2, 1.44, 1.61 and 2.45) x 10(6) /kg from the primed marrow harvest. None of the five patients previously exposed to stem cell toxins or fludarabine achieved > 0.85 x 10(6) /kg CD34 + cells with the primed marrow harvest. A significant difference was noted between G-CSF primed blood and marrow for CD34 + cells but not for GM-CFU ( p = 0.011 and p = 0.135, respectively, paired t-test). All evaluable patients engrafted; a median ANC > 0.5 x 10(9) /L recovery was achieved on D + 12 (range + 9 to + 17) in 12 of 13 evaluable patients - one died on D + 9 without recovery. The last day of platelet transfusion occurred at a median D + 13 (range + 8 to > + 66); only one patient remained platelet transfusion-dependent beyond D + 34. As anticipated, patients with higher numbers of CD34 + cells transplanted had somewhat more rapid recoveries. Although stem cell damage is obviously a key factor in mobilization failure patients, these findings raise the possibility that poor mobilization, at least in some patients, results from a mechanism other than, or in addition to, simple stem cell damage. Moreover, they raise the issue of the minimum number of marrow CD34 + - or more arguably other - cells needed for adequate short- and long-term reconstitution. The role of G-CSF in this situation, especially regarding dose and/or schedule, is intriguing but remains to be clarified. G-CSF primed marrow harvest is a potential option in certain poor mobilizers but, as fully expected, is frequently inadequate. Whether such is preferable to "steady-state" marrow harvest, continued or repeated G-CSF primed cytapheresis (with or without chemotherapy), or primed marrow with G-CSF in other schedules - or with other cytokines - is unclear and will be the subject of further study.     

Successful peripheral blood stem cell harvesting with granulocyte colony-stimulating factor alone after previous mobilization failure

A total of 138 patients whose stem cell mobilization failed following chemotherapy and granulocyte colony--stimulating factor (G-CSF) at a dose of 5 microg/kg/d were given a higher dose of G-CSF (10 microg/kg/d) for 5 days after a 7-day resting period. Stem cell mobilization was successful in 90 patients, who yielded a median of 3.5x10(6) CD34(+) cells/kg, partially successful in 17 patients (1-2.4x10(6) CD34+ cells/kg) and failed in the remaining 31 patients.     

High-dose ifosfamide and etoposide with filgrastim for stem cell mobilization in patients with advanced ovarian cancer

High-dose chemotherapy combined with autologous peripheral blood stem cell transplantation has shown promise as treatment for recurrent or persistent epithelial ovarian cancer. We evaluated the stem cell mobilization regimen of high-dose ifosfamide plus etoposide in 32 patients with epithelial ovarian cancer, who had a positive second-look laparatomy or recurrent disease. Ifosfamide was given at 10 g/m2 by continuous i.v. from days 1 to 3. Etoposide was given at 150 mg/m2 every 12 h for six doses on days 1-3. Filgrastim was given at 10 microg/kg/d s.c. from day 5 until the completion of peripheral blood stem cell harvest. Fourteen of 32 patients had measurable or evaluable disease before mobilization therapy and were assessed for response. In nine (64%) of the 14 patients, treatment response was demonstrated, and these patients received a second cycle of mobilization therapy. The target CD34+ cell dose (>8 x 106 cells/kg) was achieved with a median of one apheresis (range 1-5). A median of 25.1 (range 8.0-122.5) x 106 CD34+ cells/kg body weight was collected. Non-hematologic toxicity was limited to grade 2 renal dysfunction in one patient and grade 2 hepatic dysfunction in three patients. In this patient group, high-dose ifosfamide plus etoposide with filgrastim support was well tolerated, lead to successful stem cell harvest and had antitumor activity.     

Successful peripheral blood stem cell mobilization with etoposide (VP-16) in patients with relapsed or resistant lymphoma who failed cyclophosphamide mobilization.

High-dose chemotherapy (HDCT) followed by autologous blood stem cell transplantation is considered the treatment of choice for patients with relapsed or resistant aggressive non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD). However, several authors report failure of standard mobilization regimens in 29% to 56% of these patients making the completion of HDCT impossible and as a result, negatively influencing long-term outcome. Thus, effective new regimens for patients failing initial mobilization are needed. Here we report the results of using etoposide as a mobilizing agent in 16 patients with primary resistant or relapsed malignant lymphoma who had failed prior mobilization of peripheral blood stem cells (PBSC) with cyclophosphamide (4 g/m2) followed by G-CSF. The use of etoposide 500 mg/m2 (days 1-4) + G-CSF resulted in the successful collection of adequate numbers of PBSC with a median harvest of 3.6 x 10(6)/kg (range 2.2-12.6) CD34+ cells in all 16 patients. In 7/16 (44%) patients, the target yield of at least 2.0 x 10(6) CD34+ cells was harvested by a single apheresis and the maximum number of separations for all patients was two. No excessive toxicities appeared, allowing all patients to proceed to myeloablative chemotherapy. In addition, median peak values of circulating CD34+ cells were significantly higher after etoposide as compared to cyclophosphamide (49.2/microl vs 4.7/microl; P = 0.0004). These results indicate that etoposide + G-CSF is a highly effective mobilization regimen in patients who have failed cyclophosphamide mobilization.     

Peripheral blood stem cell mobilization by granulocyte colony-stimulating factor alone and engraftment kinetics following autologous transplantation in children and adolescents with solid tumor

In 56 pediatric and adolescent patients (median age 7 years, range 1-21) with various solid tumors, peripheral blood stem cells (PBSC) were mobilized with granulocyte colony-stimulating factor (G-CSF) alone, and the yields of PBSC and engraftment kinetics following autologous peripheral blood stem cell transplantation (PBSCT) were evaluated retrospectively. Granulocyte colony-stimulating factor (10 microg/kg) was injected subcutaneously for mobilization when patients showed no influence of previous chemotherapy, and administration was continued for 5 days. The peaks of CD34+ cells and colony-forming units-granulocyte/macrophage in the blood were observed on days 4 through 6 of G-CSF administration in all patients. Peripheral blood stem cell harvest was commenced on day 5 of G-CSF treatment. Compared to the results in patients mobilized by chemotherapy plus G-CSF (N=18), the progenitor cell yields were lower in patients mobilized with G-CSF alone. However, there were no significant differences in WBC and ANC engraftment compared to the chemotherapy plus G-CSF mobilization group. Platelet recovery following autologous PBSCT was delayed in patients mobilized with G-CSF alone. The median time taken for ANC and platelet counts to reach 0.5 x 10(9) and 20 x 10(9)/l was 12 days (range: 9-28) and 15 days (8-55), respectively, in all patients who received PBSC mobilized by G-CSF alone. In summary, mobilization with G-CSF alone can mobilize sufficient CD34+ cells for successful autografting and sustained hematological reconstitution in pediatric and adolescent patients with solid tumors, and even in heavily pre-treated patients.     

EPO in combination with G-CSF improves mobilization effectiveness after chemotherapy with ifosfamide, epirubicin and etoposide and reduces costs during mobilization and transplantation of autologous hematopoietic progenitor cells

A successful stem cell harvest is a prerequisite for peripheral blood SCT. We investigated the number of CD34(+) cells mobilized, the number of leukaphereses needed and the expenses of treatment for 28 patients with multiple myeloma randomly assigned to receive either G-CSF alone or G-CSF+EPO for stem cell mobilization after chemotherapy with ifosfamide, epirubicin and etoposide. All patients treated with G-CSF+EPO reached the threshold of 6 x 10(6) CD34(+) cells per kg body weight (kgbw), with a mean of 1.3 leukaphereses. On average 15.4 x 10(6) CD34(+) cells/kgbw were collected. In the G-CSF-alone group, the mean number of leukaphereses was 1.8, and 12.6 x 10(6) CD34(+) cells/kgbw were collected, and two patients failed the threshold. Overall costs per patient for mobilization and leukaphereses were 8339 euro (G-CSF+EPO) and 8842 euro (G-CSF). After transplantation, fewer blood transfusions (0.6 versus 1.3, P=0.05), fewer days on antibiotics (2.3 versus 6.1, P=0.02) and a shorter hospital stay (15.2 versus 17.8, P=0.06) were noted in the G-CSF+EPO group resulting in a 19.2% reduction of costs for each transplant (P=0.018). In summary, EPO improves the mobilization efficiency of G-CSF and so reduces costs of mobilization and SCT.     

Single Dose Preemptive Plerixafor for Stem Cell Mobilization for ASCT After Lenalidomide Based Therapy in Multiple Myeloma: Impact in Resource Limited Setting

Peripheral blood stem cell mobilization with cytokines for autologous stem cell transplant in multiple myeloma is adversely affected by initial induction therapy consisting of either Lenalidomide or cytotoxic drugs, with failure rates of up to 45%. The use of Plerixafor with G-CSF for PBSC mobilisation significantly improves the chances of a successful mobilization. Plerixafor is a costly therapy and increases the overall costs of ASCT which can affect the number of patients being taken up for ASCT in resource limited settings. We prospectively studied the impact of single dose preemptive Plerixafor for PBSC mobilization in patients with prior Lenalidomide exposure. 26 patients who had received Lenalidomide based induction protocol underwent PBSC mobilisation during the study period with G-CSF 10 μg/kg/day SC for 4 days and single dose preemptive Plerixafor 240 μg/kg SC stat 11 h before the scheduled PB stem cell harvest on D5, based on a D4 PB CD34+ counts of <20/μL. A median of 07 cycles of Lenalidomide based combination therapy was used for induction therapy prior to ASCT. 84% patients underwent successful mobilization with one sitting of stem cell harvest post a single dose of Inj Plerixafor. 7.6% patients failed to mobilise the predefined minimum cell dose of CD34 and could not be taken up for ASCT. The median CD34% of the harvest bag sample was 0.33% (0.1–0.97%). Injection site erythema (34%), paresthesia’s (34%) and nausea (30%) were the commonest adverse events reported post Inj Plerixafor. We did a real-world cost analysis for a resource limited setting for PBSC mobilization and found significant cost savings for the preemptive Plerixafor group.     

Efficacy of further attempts to mobilize CD34+ peripheral stem cells with alternative procedures after primary failure

19 patients who failed the target collection of at least 2.5 x 10(6) CD34+ cells/kg underwent further mobilization procedures either with granulocyte-colony-stimulating factor (G-CSF) alone after failure to chemotherapy plus G-CSF (group 1), or with chemotherapy plus G-CSF (group 2), or with high-dose G-CSF (24 microg/kg) alone (group 3) after failure to respond to standard dose of G-CSF (10 microg/kg) alone. In all groups, an increase in median CD34+ cell yield could be observed following alternative procedures (1.1- to 1.9 x 10(6) kg; p = 0.02). The highest increase in CD34+ cell harvest was achieved in group 1 (0.85 to 2.2 x 10(6) kg), followed by group 2 (1. 2 to 1.7) and group 3 (1.0 to 1.4), but without statistically significant difference between the mobilization technologies. All patients with more than 1.0 x 10(6) CD34+ cells/kg in the first apheresis procedure reached the overall target of 2.5 x 10(6) CD34+ cells/kg after a second or subsequent mobilization procedure. In contrast, only 3 of 8 patients (37%) with less than 1.0 x 10(6) CD34+ cells in the first harvest could reach the target of 2.5 x 10(6) CD34+ cells after further mobilization attempts.     

Successful mobilization of peripheral blood stem cells after addition of ancestim (stem cell factor) in patients who had failed a prior mobilization with filgrastim (granulocyte colony-stimulating factor) alone or with chemotherapy plus filgrastim

This study assessed the ability of recombinant human stem cell factor (rHuSCF) to mobilize stem cells in 44 patients who had failed a prior mobilization (CD34(+) yield 0.5-1.9 x 10(6)/kg BW) with filgrastim-alone or chemotherapy-plus-filgrastim. The same mobilization regimen was used with the addition of rHuSCF. In the filgrastim-alone group (n=13), rHuSCF 20 microg/kg was started 3 days before filgrastim and continued for the duration of filgrastim. In the chemotherapy-plus-filgrastim group (n=31), rHuSCF 20 microg/kg/day plus filgrastim 5-10 microg/kg/day were administered concurrently. Leukaphereses were continued to a maximum of four procedures or a target of >or=3 x 10(6) CD34(+) cells/kg. In both groups, CD34(+) yield (x 10(6)/kg BW) of the study mobilization was higher than that of the prior mobilization (median: 2.42 vs 0.84 P=0.002 and 1.64 vs 0.99 P=<0.001, respectively). In all 54 and 45% of patients in the filgrastim-alone group and chemotherapy-plus-filgrastim group, respectively, reached the threshold yield of 2 x 10(6)/kg. The probability of a successful mobilization was the same in those with a CD34+ yield of 0.5-0.75 x 10(6)/kg BW in the prior mobilization as in those with 0.76-1.99 x 10(6)/kg BW. Downmodulation of c-kit expression and a lower percentage of Thy-1 positivity in the mobilized CD34(+) cells were noted in the successful mobilizers compared with those in the poor mobilizers. This study shows that rhuSCF is effective in approximately half the patients who had failed a prior mobilization and allows them to proceed to transplant. It also points to the likely role of the SCF/c-kit ligand pair in mobilization.     

Automated collection of peripheral blood stem cells with the COBE spectra for autotransplantation

BACKGROUND: A convenient, effective and safe peripheral blood stem cell (PBSC) apheresis procedure is desirable to cope with the increasing requirements for PBSC collections. We performed PBSC harvesting with the novel COBE Spectra AutoPBSC(TM) system using the default software configuration recommended by the manufacturer. We analyzed collection parameters and clinical efficiency of harvested autografts following high-dose chemotherapy (HDCT). PATIENTS AND METHODS: Eighty-one patients underwent 102 harvests after standard chemotherapy plus filgrastim (5-10 microg/kg/day) to obtain a target of >/=2.5 x 10(6) CD34+ cells/kg for autologous blood stem cell transplantation. Conventional-volume leukaphereses (median: 11 liters) were performed using the manufacturer's standard software default regarding inlet flow, harvest/chase volume (3/7 ml) and number of collection cycles. The ratio of ACD-A to whole blood was initially set at 1:12 (56 collections), later at 1:10 (46 aphereses). RESULTS: With respect to preapheresis counts of 93 (9-876) CD34+ cells/microl, 69 patients (85.2%) achieved >/=2.5 x 10(6) CD34+ cells/kg by the first apheresis. PBSC products contained medians of 5.0 x 10(6) (0.7-77.3) CD34+ cells/kg and 13.8 x 10(4) (2.3-105.0) CFU-GM/kg. A preapheresis count of >/=40 CD34+ cells/microl predicted a single-apheresis yield of >/=2.5 x 10(6) CD34+ cells/kg. Apheresis products showed a high mononuclear cell (MNC) purity of >/=89%. The median overall collection efficiency of CD34+ cells (CD34-CE) was 42.6% (12.2-87.4). The CD34-CE decreased significantly with increasing numbers of circulating CD34+ cells: 52.5% at CD34+ cells <40/microl versus 41.0% at CD34+ cells >/=40/microl (p 0.5 x 10(3)/microl, 10 (8-13) days for WBC >1.0 x 10(3)/microl and 11 (8-17) days for platelets >20 x 10(3)/microl. CONCLUSIONS: As a result of efficient PBSC mobilization, a single conventional-volume leukapheresis with the COBE Spectra AutoPBSC system resulted in hematopoietic autografts with >/=2.5 x 10(6) CD34+ cells/kg in 85% of patients. Following the standard PBSC apheresis recommendations of the manufacturer, the AutoPBSC system assures PBSC products with a high MNC purity and a moderate CD34-CE that declines significantly at increasing levels of circulating CD34+ cells. Leukaphereses performed at an ACD-A to whole blood ratio of 1:10 should run without coagulation problems.     

CD34+ cell dose and hematologic recovery in allogeneic peripheral blood stem cell transplantation

Allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) has been performed as an alternative to bone marrow transplantation (BMT). Here we report poor mobilization with granulocyte-colony stimulating factor (G-CSF) and engraftment kinetics in Allo-PBSCT. Sixteen patients (aged 6-61 yr, median 34 yr) received allogeneic peripheral blood stem cells from related donors (aged 15-68 yr, median 37 yr) after myeloablative therapy. Nine of the patients had standard-risk disease and 7 had high-risk disease. The donors received G-CSF at a dose of 10 micrograms/kg/day by subcutaneous injection for 4 to 6 days. Peripheral blood stem cells were subsequently collected in 1 to 3 aphereses and infused immediately. All patients received G-CSF after transplantation. Fifteen patients underwent Allo-PBSCT and one underwent Allo-PBSCT plus BMT. The mean number of CD34+ cells infused in the 15 Allo-PBSCT patients was 6.32 x 10(6)/kg (range 1.28-14.20). The outcomes were compared with 9 identically treated patients who underwent Allo-BMT. The median times until engraftment for neutrophils > 500/microliter and platelets > 20,000/microliter were 14 (range 10-17) and 15 (range 11-50) days in the Allo-PBSCT group and 17 (range 13-29) and 20 (range 16-160) days in the Allo-BMT group, respectively (p = 0.0177 and p = 0.003). Three donors were considered to have poor mobilization (< 2 x 10(6) CD34+ cells/kg of the recipient); two of them yielded 1.28 and 1.78 x 10(6) CD34+ cells/kg in 3 apheresis procedures. The patients who received cells from these donors showed prompt neutrophil engraftment, but one showed delayed platelet engraftment and another died of grade IV acute GVHD before reaching 20,000 platelets/microliter. An additional bone marrow harvest was necessary from one donor because of poor mobilization(0.17 x 10(6) CD34+ cells/kg). Thus, Allo-PBSCT results in more rapid engraftment. It will be necessary to clarify the minimum CD34+ cell dose for complete engraftment in a larger series of trials.     

Efficient mobilization of peripheral blood stem cells following CAD chemotherapy and a single dose of pegylated G-CSF in patients with multiple myeloma

High-dose chemotherapy followed by autologous blood stem cell transplantation is the standard treatment for myeloma patients. In this study, CAD (cyclophosphamide, adriamycin, dexamethasone) chemotherapy and a single dose of pegfilgrastim (12 mg) was highly effective in mobilizing peripheral blood stem cells (PBSCs) for subsequent transplantation, with 88% of patients (n = 26) achieving the CD34+ cell harvest target of > or = 7.50 x 10(6) CD34+ cells/kg body weight, following a median of two apheresis procedures (range 1-4) and with first apheresis performed at a median day 13 after CAD application (range 10-20). Patients treated with pegfilgrastim showed a reduced time to first apheresis procedure from mobilization compared with filgrastim-mobilized historical matched controls (n = 52, P = 0.015). The pegfilgrastim mobilization regimen allowed for transplantation of a median of 3.58 x 10(6) CD34+ cells/kg body weight while leaving sufficient stored cells for a second high-dose regimen and back-ups in most patients. Engraftment following transplantation was comparable to filgrastim, with a median time of 14 days to leucocyte > or =1.0 x 10(9)/l (range 10-21) and 11 days to platelets > or = 20 x 10(9)/l (range 0-15). The results of this study thus provide further support for the clinical utility of pegfilgrastim for the mobilization of PBSC following chemotherapy in cancer patients scheduled for transplantation.     

An analysis of the optimal timing of peripheral blood stem cell harvesting following priming with cyclophosphamide and G-CSF

Increasing demand on the apheresis service makes efficient harvesting of peripheral blood stem cells (PBSCs) essential. A total of 168 adult patients with haematological malignancy were primed using low-moderate dose cyclophosphamide (1.5-3 g/m(2)) with G-CSF 5-10 microg/kg per day. Harvesting was booked and peripheral blood (PB) counts first checked between 6 and 10 days post-priming. One hundred and thirty (77%) patients harvested successfully (total harvest yield > or =2 x 10(6) CD34(+)/kg) and the median PBSC collection per procedure was 2.18 x 10(6)/kg (range 0.1-14.5). Only more lines of prior chemotherapy predicted failure to harvest in multivariate analysis (P=0.003). The PB CD34(+) cell count correlated significantly with harvest yield (r=0.8448, P<0.0001). A PB CD34(+) count > or =10/microl predicted a collection of > or =2 x 10(6)/kg (positive-predictive value of 61%, negative-predictive-value 100%). Patients first attending day 9 required significantly fewer visits to achieve a successful harvest than those first attending days 6-8 without increasing the risk of failure. No significant difference in failure rates, number of days attending and total harvest yield was found between days 9 and 10 attendees. Collection from day 9 may however enable higher target yields to be achieved. PB CD34(+) count monitoring should commence and harvesting booked from day 9 to optimize both the harvest and the efficiency of the PBSC harvesting service.     

Analysis of remobilization success in patients undergoing autologous stem cell transplants who fail an initial mobilization: risk factors, cytokine use and cost

Inadequate stem cell mobilization is seen in approximately 25% of patients undergoing autotransplantation for hematologic malignancies. Remobilization strategies include chemotherapy/cytokine combinations or high-dose cytokines alone or in combination. From 1/1997 to 7/2002, we remobilized 86 patients who failed an initial mobilization (median total CD34=0.72 x 10(6)/kg) in sequential cohorts using high-dose G-CSF (32 microg/kg/day) or G-CSF(10 microg/kg/day)+GM-CSF (5 microg/kg/day). No difference in CD34/kg yields were seen (G-CSF alone: 2.2 x 10(6) and G-CSF+GM-CSF 1.6 x 10(6)) in the median 3 aphereses performed (P=0.333). Of the 86, 23 (27%) failed the second mobilization; 14 were remobilized again (yield=1.5 x 10(6) CD34/kg; three aphereses). Of the 86, 93% went to transplant: three progressed, and three had inadequate stem cells. Significant risk factors for a failed remobilization were: number of stem-cell-damaging regimens (P=0.015), time between last chemotherapy and first mobilization (P=0.028), and higher WBC at initiation of first mobilization (P=0.04). High-dose G-CSF (32 microg/kg/day) was more costly @ USD $9,016, vs $5,907 for the G-CSF+GM-CSF combination (P<0.001). Most patients failing an initial mobilization benefit from a cytokine only remobilization. Lower cost G-CSF+GM-CSF is as effective as high-dose G-CSF.     

Hypercholesterolemia and its association with enhanced stem cell mobilization and harvest after high-dose cyclophosphamide+G-CSF

High-dose chemotherapy with autologous peripheral blood SCT is a common treatment option in several hematological and non-hematological malignancies. So far, prediction of successful stem cell mobilization and harvest is limited. Just recently, hypercholesterolemia was shown to increase mobilization of hematopoietic progenitor cells into the peripheral circulation in mice. On the basis of these results, we performed a retrospective multivariate analysis incorporating a variety of clinical parameters in 83 patients following high-dose cyclophosphamide+G-CSF treatment. Interestingly, we found a significant positive correlation between stem cell mobilization and harvest for plasma cholesterol and lactate dehydrogenase (LDH) only. Patients with hypercholesterolemia showed a substantially higher median peripheral blood CD34(+)-peak (126 vs 47/μL, P=0.003), higher median number of harvested CD34(+)-cells/kg (9.6 vs 7.4 × 10(6)/kg, P<0.001) and a sufficient number for at least one SCT in a remarkably higher proportion (84.9 vs 52.9%, P=0.003) compared with patients with normal cholesterol levels.     

An antecedent diagnosis of refractory anemia with excess blasts has no influence on mobilization of peripheral blood stem cells and hematopoietic recovery after autologous stem cell transplantation in acute myeloid leukemia

Several studies have reported data on factors influencing mobilization of peripheral blood stem cells (PBSC) in non-myeloid malignancies. On the contrary, data from patients with acute myeloid leukemia (AML) are very limited, in particular, as the impact of an antecedent diagnosis of refractory anemia with excess blasts (RAEB) on mobilization of PBSCs as well as hematopoietic recovery after autologous stem cell transplantation (ASCT) is concerned. We retrospectively analyzed a cohort of 150 consecutive AML patients in first complete remission in order to make a comparison between patients with de novo AML and secondary AML (s-AML) in terms of CD34 positive (CD34+) cells mobilization and number of leukapheresis needed to collect at least one single stem cell graft. Data concerning hematopoietic recovery after ASCT were also compared. The successful mobilization rate (>2 x 10(6) CD34+ cells/kg) was comparable between de novo AML patients (87%) and those with s-AML (76%), P:0.21. No statistically significant difference was found in terms of either median number of CD34+ cells collected (P:0.44) or CD34+ cells peak in peripheral blood (P:0.28). Both groups of patients needed a median of two apheresis (P:0.45) and no difference was found on the median number of CD34+ cells collected per single apheresis (P:0.59). Finally, neutrophil and platelet recovery after ASCT were comparable between the two groups. An antecedent diagnosis of RAEB has no impact on mobilization and collection of PBSCs in AML as well as on hematopoietic recovery after ASCT.