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

Etoposide-mediated interleukin-8 secretion from bone marrow stromal cells induces hematopoietic stem cell mobilization

Background

We assessed the mechanism of hematopoietic stem cell (HSC) mobilization using etoposide with granulocyte-colony stimulating factor (G-CSF), and determined how this mechanism differs from that induced by cyclophosphamide with G-CSF or G-CSF alone.

Methods

We compared the clinical features of 173 non-Hodgkin’s lymphoma patients who underwent autologous peripheral blood stem cell transplantation (auto-PBSCT). Additionally, we performed in vitro experiments to assess the changes in human bone marrow stromal cells (hBMSCs), which support the HSCs in the bone marrow (BM) niche, following cyclophosphamide or etoposide exposure. We also performed animal studies under standardized conditions to ensure the following: exclude confounding factors, mimic the conditions in clinical practice, and identify the changes in the BM niche caused by etoposide-induced chemo-mobilization or other mobilization methods.

Results

Retrospective analysis of the clinical data revealed that the etoposide with G-CSF mobilization group showed the highest yield of CD34+ cells and the lowest change in white blood cell counts during mobilization. In in vitro experiments, etoposide triggered interleukin (IL)-8 secretion from the BMSCs and caused long-term BMSC toxicity. To investigate the manner in which the hBMSC-released IL-8 affects hHSCs in the BM niche, we cultured hHSCs with or without IL-8, and found that the number of total, CD34+, and CD34+/CD45- cells in IL-8-treated cells was significantly higher than the respective number in hHSCs cultured without IL-8 (p = 0.014, 0.020, and 0.039, respectively). Additionally, the relative expression of CXCR2 (an IL-8 receptor), and mTOR and c-MYC (components of IL-8-related signaling pathways) increased 1 h after IL-8 treatment. In animal studies, the etoposide with G-CSF mobilization group presented higher IL-8-related cytokine and MMP9 expression and lower SDF-1 expression in the BM, compared to the groups not treated with etoposide.

Conclusion

Collectively, the unique mechanism of etoposide with G-CSF-induced mobilization is associated with IL-8 secretion from the BMSCs, which is responsible for the enhanced proliferation and mobilization of HSCs in the bone marrow; this was not observed with mobilization using cyclophosphamide with G-CSF or G-CSF alone. However, the long-term toxicity of etoposide toward BMSCs emphasizes the need for the development of more efficient and safe chemo-mobilization strategies.

Etoposide + Granulocyte Colony-Stimulating Factor and Optional Plerixafor in Patients Who Failed Chemomobilization with or without Plerixafor

We conducted a retrospective study of 62 patients undergoing etoposide (2 g/m²) + granulocyte colony-stimulating factor (G-CSF; 10 patients also received additional plerixafor) as a salvage stem cell mobilization regimen after previous unsuccessful chemomobilization with or without plerixafor. The median peak CD34⁺ values after etoposide + G-CSF ± plerixafor was 54.07 CD34⁺/μL compared with 9.6 CD34⁺/μL after previous mobilization attempts (P < .001). The median yield was 6.33 × 10⁶ CD34⁺ cells/kg per 2 apheresis. Etoposide + G-CSF ± plerixafor mobilization regimen resulted in 91.53% successful mobilizations and 89.83% of patients proceeding to autologous stem cell transplantation. All 7 patients who had previously failed plerixafor-based mobilization attempts were successfully mobilized with etoposide + G-CSF ± plerixafor and proceeded to autologous stem cell transplantation. The most common grades 3 to 4 adverse events of etoposide + G-CSF ± plerixafor were febrile neutropenia (69.35%), mucositis (51.62%), and bacteremia (20.97%). No fatal outcomes were observed. Rates of 12-month overall survival and progression-free survival were 88.71% and 70.97%, respectively. Etoposide + G-CSF ± plerixafor is an effective regimen for salvage stem cell mobilization also in patients who failed plerixafor, with most patients undergoing autologous stem cell transplantation. The adverse event rate may warrant a decrease in the dose of etoposide.

Optimal chemo-mobilization for the collection of peripheral blood stem cells in patients with multiple myeloma

BACKGROUND

For successful autologous stem cell transplantation, the collection of a sufficient number of hematopoietic stem cells after induction therapy is essential for transplant candidates with multiple myeloma (MM).

METHODS

In this study, we compared the efficacy and safety of stem cell mobilization using cyclophosphamide (CY; 3.0 g/m² on day 1) or etoposide (VP-16; 375 mg/m² on days 1 and 2) in patients with MM. Granulocyte-colony stimulating factor (G-CSF, 10 μg/kg/day, subcutaneously) was administered from the onset of neutropenia to the final day of collection.

RESULTS

Sixty-five patients were mobilized with a combination of CY and G-CSF, and 63 were mobilized with a combination of VP-16 and G-CSF. All patients were mobilized within 7 months of beginning frontline treatment. The median number of CD34⁺ cells collected was significantly higher in the VP-16 mobilization group than in the CY mobilization group (27.6 ×  10⁶ CD34⁺/kg vs. 9.6 × 10⁶ CD34⁺/kg, P <  0.001). The rate of mobilization failure, defined as < 2.0 × 10⁶ CD34⁺/kg collected in three apheresis procedures, was lower in the VP-16 group than in the CY group (1.6% vs. 10.8%, P = 0.062). Severe infections during the mobilization period were more frequent in the CY group than in the VP-16 group (18.5% vs. 7.9%, P = 0.117).

CONCLUSION

In conclusion, an intermediate dose of VP-16 with G-CSF appears to be an effective and tolerable chemo-mobilization method compared to CY and G-CSF, particularly in cases where use plerixafor in MM is difficult.

Bendamustine, etoposide, and dexamethasone to mobilize peripheral blood hematopoietic stem cells for autologous transplantation in non-Hodgkin lymphoma

Background

Bendamustine is a chemotherapeutic agent that has shown broad activity in patients with lymphoid malignancies. It contains both alkylating and nucleoside analog moieties, and thus, is not commonly used for stem cell mobilization due to concerns that it may adversely affect stem cell collection. Here we describe the lymphoma subset of a prospective, non-randomized phase II study of bendamustine, etoposide, and dexamethasone (BED) as a mobilization agent for lymphoid malignancies.

Methods

This subset analysis includes diffuse large B-cell lymphoma (N=3), follicular lymphoma (N=1), primary mediastinal B-cell lymphoma (N=1), and NK/T-cell lymphoma (N=1). Patients received bendamustine (120 mg/m² IV d 1, 2), etoposide (200 mg/m² IV d 1–3), and dexamethasone (40 mg PO d 1–4) followed by filgrastim (10 mcg/kg/d sc. through collection).

Results

We successfully collected stem cells from all patients, with a median of 7.9×10⁶/kg of body weight (range, 4.4 to 17.3×10⁶/kg) over a median of 1.5 days (range, 1 to 3) of apheresis. All patients who received transplants were engrafted using kinetics that were comparable to those of other mobilization regimens. Three non-hematologic significant adverse events were observed in one patient, and included bacterial sepsis (grade 3), tumor lysis syndrome (grade 3), and disease progression (grade 5).

Conclusion

For non-Hodgkin lymphoma, mobilization with bendamustine is safe and effective.

Effective chemomobilization with etoposide and cytarabine (EC regimen) in lymphoma patients: a single-center, retrospective, observational study

Objective

Autologous stem cell transplantation is an important strategy for patients with relapsed or refractory lymphoma. Although various regimens for peripheral blood stem cell collection have been used, the optimal regimen has not yet been established. We aimed to evaluate the mobilization efficacy and safety of the regimen consisted of etoposide and cytarabine (EC regimen).

Methods

We retrospectively analyzed the clinical data of 46 lymphoma patients who received peripheral blood stem cell mobilization with the EC regimen [etoposide (100 mg/m2/day, days 1-4) and cytarabine (100 mg/m2/day, days 1-4)] at Toyohashi municipal hospital from 2004 to 2013.

Results

The median age of the patients was 55 years. The most common underlying diseases were diffuse large B-cell lymphoma (46%) and follicular lymphoma (26%). Three-quarters of patients were in their second complete or partial remission. The median total number of collected CD34+ cells was 10.6 × 106 kg-1. Forty-two patients (91%) yielded at least 2 × 106 kg-1 CD34+ cells within a median of 2 apheresis days, and 33 patients (72%) achieved it with only one apheresis. Successful mobilization was observed in five of six patients who failed to mobilize previously. Although febrile neutropenia occurred in 22 patients (48%), no fatal infection was observed.

Conclusion

The EC regimen was highly effective in lymphoma patients, including patients who mobilized poorly with other regimens.

Bendamustine, etoposide and dexamethasone to mobilize peripheral blood hematopoietic stem cells for autologous transplantation in patients with multiple myeloma

Chemotherapeutic agents without cross-resistance to prior therapies may enhance PBSC collection and improve patient outcomes by exacting a more potent direct antitumor effect before autologous stem cell transplant. Bendamustine has broad clinical activity in transplantable lymphoid malignancies, but concern remains over the potential adverse impact of this combined alkylator-nucleoside analog on stem cell mobilization. We performed a prospective, nonrandomized phase II study including 34 patients with multiple myeloma (MM) (n=34; International Staging System (ISS) stages I (35%), II (29%) and III (24%); not scored (13%)) to evaluate bendamustine's efficacy and safety as a stem cell mobilizing agent. Patients received bendamustine (120 mg/m2 IV days 1, 2), etoposide (200 mg/m2 IV days 1-3) and dexamethasone (40 mg PO days 1- 4) (bendamustine, etoposide and dexamethasone (BED)) followed by filgrastim (10 μg/kg/day SC; through collection). All patients (100%) successfully yielded stem cells (median of 21.60 × 106/kg of body weight; range 9.24-55.5 × 106/kg), and 88% required a single apheresis. Six nonhematologic serious adverse events were observed in 6 patients including: neutropenic fever (1, grade 3), bone pain (1, grade 3) and renal insufficiency (1, grade 1). In conclusion, BED safely and effectively mobilizes hematopoietic stem cells.

Stem Cell Mobilization with G-CSF versus Cyclophosphamide plus G-CSF in Mexican Children

Fifty-six aphaereses were performed in 23 pediatric patients with malignant hematological and solid tumors, following three different protocols for PBPC mobilization and distributed as follows: A: seventeen mobilized with 4 g/m² of cyclophosphamide (CFA) and 10 μg/kg/day of granulocyte colony stimulating factor (G-CSF), B: nineteen with CFA + G-CSF, and C: twenty only with G-CSF when the WBC count exceeded 10 × 10⁹/L. The average number of MNC/kg body weight (BW)/aphaeresis was 0.4 × 10⁸ (0.1–1.4), 2.25 × 10⁸ (0.56–6.28), and 1.02 × 10⁸ (0.34–2.5) whereas the average number of CD34+ cells/kg BW/aphaeresis was 0.18 × 10⁶/kg (0.09–0.34), 1.04 × 10⁶ (0.19–9.3), and 0.59 × 10⁶ (0.17–0.87) and the count of CFU/kg BW/aphaeresis was 1.11 × 10⁵ (0.31–2.12), 1.16 × 10⁵ (0.64–2.97), and 1.12 × 10⁵ (0.3–6.63) in groups A, B, and C, respectively. The collection was better in group B versus group A (p = 0.007 and p = 0.05, resp.) and in group C versus group A (p = 0.08 and p = 0.05, resp.). The collection of PBPCs was more effective in the group mobilized with CFM + G-CSF when the WBC exceeded 10 × 10³/μL in terms of MNC and CD34+ cells and there was no toxicity of the chemotherapy.

Hematopoietic stem and progenitor cell harvesting: technical advances and clinical utility

Hematopoietic stem and progenitor cell (HSPC) transplantations require prior harvesting of allogeneic or autologous HSPCs. HSPCs are usually present in bone marrow (BM) during the entire life, in cord blood (CB) at birth, or in peripheral blood (PB) under particular circumstances. HSPCs were first harvested in BM and later in CB and PB, as studies showed interesting features of such grafts. All harvesting methods were in use throughout the years, except BM harvesting for HSPC autologous transplantation, which was replaced by PB harvesting. BM, CB, and PB harvesting methods have been developed, and materials and devices technically improved to increase the number of HSPCs harvested. In parallel, knowing the features of the donors or patients associated with successful numbers of HSPCs allows the adaptation of appropriate harvesting methods. Moreover, it is important to ensure the safety of donors or patients while harvesting. This review describes the methods used for harvesting based on recent studies or developments around these methods, and more particularly, the means developed to increase the numbers of HSPCs harvested in each method. It also explains briefly the influence of technical improvements in HSPC harvesting on potential changes in HSPC graft composition.

Intermediate doses of cytarabine plus granulocyte-colony-stimulating factor as an effective and safe regimen for hematopoietic stem cell collection in lymphoma patients with prior mobilization failure

BACKGROUND

High-dose chemotherapy supported by autologous stem cell transplantation (ASCT) is an effective treatment for patients with lymphomas. However, failure to reach the minimum threshold of hematopoietic stem cells to proceed to ASCT may occur, even with the most effective strategies currently available.

STUDY DESIGN AND METHODS

We report on 33 patients diagnosed with lymphoma who had at least one prior mobilization failure and received cytarabine at a dose of 400 mg/m(2) /day intravenously × 3 days plus granulocyte-colony-stimulating factor (G-CSF) 10 to 12 μg/kg/day as mobilization regimen. The median number of previous lines of chemotherapy was three.

RESULTS

Thirty-two of 33 patients (96.8%) reached the target CD34+ cell dose (>2 × 10(6) /kg). The mean (range) number of apheresis procedures was 1.8 (1-3) with 4.69 × 10(6) (1.5 × 10(6) -6.8 × 10(6) )/kg CD34+ cells obtained. All but one patient received chemomobilization in the outpatient department. Severe infections or treatment-related mortality were not observed. All patients that received ASCT (31/33) engrafted without requiring G-CSF during the posttransplant period.

CONCLUSION

This study shows that cytarabine at intermediate doses plus G-CSF in patients diagnosed with lymphoma who had a prior mobilization failure is a feasible and effective mobilization regimen.

Remobilization of hematopoietic stem cells with high-dose methotrexate and cytarabine in patients with non-Hodgkin's lymphoma and multiple myeloma after failure to mobilize with chemotherapy and cytokines

BACKGROUND

High-dose chemotherapy supported by autologous stem cell transplantation is an effective treatment for patients with relapsed or refractory non-Hodgkin's lymphomas (NHLs) and fit patients with multiple myeloma (MM). However, failure rates of hematopoietic stem cell mobilization are estimated to be between 5 and 30%, respectively. Thus, we investigated the efficacy of the combination chemotherapy of high-dose methotrexate (MTX) and cytarabine with granulocyte-colony-stimulating factor (G-CSF) as a remobilization method in those who failed a prior mobilization and collection with chemotherapy and G-CSF.

STUDY DESIGN AND METHODS

Mobilization failure was defined as a collection of fewer than 5 × 10(6) CD34+ cells after three to five apheresis procedures. MTX (3500 mg/m(2) in a 120-min infusion) on Day 1 and cytarabine (3000 mg/m(2) infusion for 120 min) on Day 4 and Day 5 were followed by G-CSF (10 μg/kg daily).

RESULTS

A total of eight patients (six NHL and two MM; median age, 55 years) who had failed in prior mobilization with conventional chemotherapy and G-CSF underwent the second mobilization as described in the method. Successful collection of CD34+ cells (> 5 × 10(6) /kg) was achieved in six patients (75%) with three to five apheresis procedures. The total yield of CD34+ cells/kg body weight was 6.28 × 10(6) /kg (median; range, 1.53 × 10(6) -10.09 × 10(6) /kg).

CONCLUSIONS

This preliminary result warrants further investigation of high-dose MTX and cytarabine plus G-CSF as a means to remobilize stem cells in those with prior failure to mobilize stem cells with chemotherapy and G-CSF.

Retrospective analysis of an efficient peripheral blood stem cell collection and the relation between infused cell dose and clinical outcome in patients with malignant lymphoma and multiple myeloma

INTRODUCTION

Etoposide (VP16) is a drug used not only for the treatment of lymphoma but also for the collection of peripheral blood stem cells (PBSCs). We analysed the efficacy and adverse effects of collecting PBSCs and the relation between the infused cell dose and the clinical outcome in lymphoid malignancies.

METHOD

Investigating 30 patients with non-Hodgkin's lymphoma, one patient with Hodgkin's lymphoma, and five patients with multiple myeloma, we compared the effects of several doses of etoposide with those of CHOP or CHOP-like treatments or salvage treatments. We also analysed the relation between the amount of CD34(+) cells collected (above or below 5.0 × 10(6) /kg/day) and prognosis of these patients.

RESULTS

We found the collected cell count to be highest in patients treated with 500 mg/m(2) of VP16 and lowest in those not treated with VP16 (P = 0.0073). A CD34(+) cell count above 100/μL on the collection day indicates that the target amount of CD34(+) cells (4.0 × 10(6) /kg) can be readily obtained and was reached most rapidly by the patients who had received 500 mg/m(2) of VP16 (P = 0.01). The longer duration of neutropenia in those patients (P = 0.000006) resulted in longer antibiotic treatment (P = 0.0052). Both progression-free survival (PFS) and overall survival (OS) were better for the patients who yielded more than 5.0 × 10(6) CD34(+) cells/kg/day (P = 0.087 for PFS and P < 0.033 for OS).

CONCLUSION

We show here that 3 days of VP16 at 500 mg/m(2) was useful for the collection of PBSCs and that patients who yielded more than 5.0 × 10(6) CD34(+) cells/kg/day survived longer than those who yielded less.

The effective use of plerixafor as a real-time rescue strategy for patients poorly mobilizing autologous CD34(+) cells

Plerixafor enhances CD34(+) cell mobilization, however, its optimal use is unknown. We hypothesized that plerixafor could "rescue" patients in the midst of mobilization when factors indicated a poor CD34(+) yield. Of 295 consecutive autologous peripheral blood mobilization attempts at our center, 39 (13%) used plerixafor as rescue strategy due to a CD34(+) cell concentration <10/μl (median 5.95/μl, n = 30), low CD34(+) cell yield from prior apheresis day (median 1.06 × 10(6) CD34(+) cells/kg, n = 7), or other (n = 2). Patients received a median of one plerixafor dose (range: 1-4). Thirty-four (87%) collected =2 × 10 (6) CD34(+) cells/kg and 26 (67%) collected =4 × 10 (6) CD34(+) cells/kg. Median collections for lymphoma (n = 24) and myeloma (n = 15) patients were 4.1 × 10(6) and 8.3 × 10(6) CD34/kg, respectively. A single dose of plerixafor was associated with an increase in the mean peripheral blood CD34(+) concentration of 17.2 cells/μl (P < 0.001) and mean increased CD34(+) cell yield following a single apheresis of 5.11 × 10(6) /kg (P < 0.03). A real-time rescue use of plerixafor is feasible and may allow targeted use of this agent. J. Clin. Apheresis, 2012. © 2012 Wiley Periodicals, Inc.

Production of podophyllotoxin from Podophyllum hexandrum: a potential natural product for clinically useful anticancer drugs

Podophyllum hexandrum Royle of family Berberidaceae is an endangered medicinal plant. Rhizome ofP.hexandrum contains several lignans which posses antitumor activity. Podphyllotoxin is the most active cytotoxic natural product. It is used as starting compound for the synthesis of anticancer drug etoposide and teniposide. Podophyllotoxin acts as an inhibitor of microtubule assembly. These drugs are used for lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. Besides this, it also shows antiviral activities by interfering with some critical viral processes. Availabilityof podophyllotoxin from plants has its limitations because of its intense collection from nature and lack of organized cultivation. The chemical synthesis of podophyllotoxin is considered to be very complicated as yet. The use of biotechnological approaches for the production of podophyllotoxin using cell cultures, organ cultures, and biotransformation route or by manipulating biosynthetic pathway proves to be an attractive alternative for production of podophyllotoxin. The present paper discusses the current status of research, limitations and future prospects for theproduction of podophyllotoxinin vitro.

Mobilization of hematopoietic stem cells into the peripheral blood

Hematopoietic stem cells can be mobilized out of the bone marrow into the blood for the reconstitution of hematopoiesis following high-dose therapy. Methods to improve mobilization efficiency and yields are rapidly emerging. Traditional methods include chemotherapy with or without myeloid growth factors. Plerixafor, a novel agent that disrupts the CXCR4-CXCL12 bond, the primary hematopoietic stem cell anchor in the bone marrow, has recently been US FDA-approved for mobilizing hematopoietic stem cells in patients with non-Hodgkin lymphoma and multiple myeloma. Plerixafor and myeloid growth factors as single agents appear safe to use in family or volunteer hematopoietic stem cells donors. Plerixafor mobilizes leukemic stem cells and is not approved for use in patients with acute leukemia. Patients failing to mobilize adequate hematopoietic stem cells with myeloid growth factors can often be successfully mobilized with chemotherapy plus myeloid growth factors or with plerixafor and granulocyte colony-stimulating factor.

Peripheral Blood Stem Cell Mobilization Tactics

OBJECTIVE

To evaluate the methods and collection techniques currently used in stem cell mobilization for patients undergoing autologous transplantation.

DATA SOURCES

Literature search was performed through PubMed (1948-August 2009) and MEDLINE (1977-August 2009). Reference citations from publications identified were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

All literature identified was reviewed for inclusion. Original research and retrospective cohorts, along with previously published systematic reviews of stem cell mobilization and growth factors, were evaluated. Abstract data on plerixafor were also reviewed.

DATA SYNTHESIS

Successful mobilization of an adequate number of progenitor cells can help ensure and improve time to neutrophil and platelet engraftment. A variety of methods have been studied to find the safest and most predictable mobilization of CD34+ progenitor cells, including use of single agents or the combinations of hematopoietic growth factors, chemotherapy, and a novel chemokine receptor 4 antagonist. Currently, granulocyte colony-stimulating factor (G-CSF) 10 Mg/kg daily started 4 days prior to apheresis remains the standard of care for initial mobilization therapy. In patients who fail to mobilize or who are at high risk for mobilization failure, cyclophosphamide in conjunction with G-CSF may be used. Plerixafor, a novel chemokine receptor antagonist, in combination with G-CSF has demonstrated superiority for achieving collection goals compared to G-CSF alone in 2 Phase 3 trials.

CONCLUSIONS

The optimal mobilization strategy is still unknown; however, colony-stimulating factors remain the most commonly used mobilization agents. Currently, chemotherapy or plerixafor in combination with G-CSF is a reasonable option in heavily pretreated and hard-to-mobilize patients with non-Hodgkin's lymphoma and multiple myeloma.

Retrospective comparison of mobilization methods for autologous stem cell transplantation in multiple myeloma

The combination of cyclophosphamide and granulocyte-colony stimulating factor (G-CSF) has widely been used to mobilize hematopoietic stem cells (HSCs) for autologous stem cell transplantation (ASCT) for multiple myeloma (MM). Recently, however, alternative approaches such as G-CSF alone or etoposide followed by G-CSF have been investigated. We, therefore, retrospectively analyzed the effects of these mobilization methods on collection yield and disease outcome in ASCT for MM. We reviewed 146 MM patients from whom we intended to collect stem cells. For mobilization, 67, 58, and 21 patients received cyclophosphamide and G-CSF, etoposide and G-CSF, and G-CSF alone (including nonmyelosuppressive chemotherapy followed by G-CSF), respectively. Among them, 136 achieved the target number of HSCs (at least 2 x 10(6)/kg). Lower creatinine and higher albumin levels at diagnosis were significantly associated with successful yield. A lower number of infused HSCs, use of the etoposide for mobilization and high ISS were associated with delayed hematopoietic recovery. The mobilization methods did not significantly affect either the successful collection of more than 2 x 10(6) CD34-positive cells/kg or PFS after ASCT. G-CSF alone was sufficient for stem cell mobilization for a single ASCT. The optimal approach to collect HSCs in MM remains to be elucidated.

Etoposide 1.0 g/m2 or 1.5 g/m2 combined with granulocyte colony-stimulating factor for mobilization of peripheral blood stem cells in patients with malignancy: efficacy and toxicity

BACKGROUND

The purpose of this study was to observe the efficacy and toxicity of etoposide at two dose levels for peripheral blood stem cell (PBSC) mobilization and disease debulking in patients with malignancy. Simultaneously, factors affecting the yield of CD34+ cells were explored.

METHODS

Thirty-eight patients received etoposide 1.0 g/m2 (group A) or 1.5 g/m2 (group B) followed by granulocyte colony-stimulating factor (G-CSF) 300 microg/day for PBSC mobilization in a non-randomized manner. Each group had 19 patients.

RESULTS

The median number of CD34+ cells collected was 17.33 x 10(6)/kg (range 4.85-89.00 x 10(6)/kg) in group A and 26.54 x 10(6)/kg (range 1.85-108.00 x 10(6)/kg) in group B. Altogether, 34/38 (89.5%) patients obtained the target total collection of at least 4 x 10(6) CD34+ cells/kg by a single leukapheresis. Vomiting was the most common grade 3/4 non-hematologic toxicity. For 19 evaluable patients, partial response was achieved in four (21.1%), stable disease in 11 (57.8%) and progressive disease in four (21.1%) patients. All parameters between the two groups did not reach a significant level. With multivariate analysis, the most predictive factor for CD34+ yield of the first leukapheresis was the percentage of CD34+ CD38(-) cells in peripheral blood.

CONCLUSION

These results indicate that etoposide combined with G-CSF is an effective and tolerable regimen for PBSC mobilization, given at a dose of either 1.0 g/m2 or 1.5 g/m2.

Successful mobilization of peripheral blood stem cells with the DHAP regimen (dexamethasone, cytarabine, cisplatinum) plus granulocyte colony-stimulating factor in patients with relapsed Hodgkin's disease

High-dose chemotherapy followed by autologous stem cell transplantation can improve the outcome of relapsed and refractory Hodgkin's disease (HD) patients. The objective of the trial was to determine the mobilizing potential of the DHAP salvage regimen (dexamethasone, cytarabine, cisplatin) for the collection of peripheral blood stem cells (PBSC) in patients with relapsed HD. The target yield of harvesting CD34 + cells was > or =2 x 10(6)/kg in order to support the subsequent myeloablative chemotherapy. Most of the 105 patients included were intensively pre-treated with different combination chemotherapy regimens prior to mobilization. The use of DHAP followed by granulocyte colony-stimulating factor (G-CSF; 10 microg/kg) resulted in the successful collection of adequate numbers of PBSC in 97.1% of patients (102 of 105) with a median harvest of CD34+ cells of 13 x 10(6)/kg (range 2.6 - 85.1). More than 2.0 x 10(6) CD34+ cells/kg were achieved in 65 of 103 (63%) patients after 1 apheresis, the maximum number of aphereses for all patients was 3. It was found that the optimal time of PBSC harvest was at days 13 - 16 after initiating the mobilization regimen. These results demonstrate that the salvage chemotherapy regimen, such as DHAP combined with G-CSF, can be successfully used to mobilize PBSC in HD patients.

Peripheral blood hematopoietic stem cell mobilization and collection efficacy is not an independent prognostic factor for autologous stem cell transplantation

BACKGROUND

The successful mobilization and collection of hematopoietic stem cells are dependent on a number of clinical factors such as previous chemotherapy and disease stage. The aim of this retrospective study was to determine whether the effectiveness of mobilization and collection is an independent prognostic factor for autologous stem cell transplantation outcome.

STUDY DESIGN AND METHODS

A total of 358 patients who received transplants from January 2003 to December 2004 (201 male and 157 female patients, ages from 2.7 to 77.3 years with median of 53 years of age) underwent autologous hematopoietic stem cell collection after mobilization with granulocyte-colony-stimulating factor (G-CSF) or G-CSF plus chemotherapy priming. This retrospective study included patients with diagnoses of acute myelogenous leukemia, non-Hodgkin's lymphoma, Hodgkin's disease, multiple myeloma, and solid tumors. All patients underwent stem cell collection until a target or a minimum CD34+ cell dose was reached. Correlations were performed between stem cell mobilization and/or collection efficacy and transplantation outcomes.

RESULTS

In general, both larger reinfused CD34+ cell dose and shorter number of days for the stem cell count to reach the minimum of 2 x 10(6) per kg CD34+ cells do not foster quicker engraftment. Reinfused CD34+ cell dose of less than 12 x 10(6) and number of days stem cell collection to reach this minimum CD34+ cell dose did not independently affect the overall survival (OS) or disease-free survival (DFS).

CONCLUSION

The effectiveness of hematopoietic stem cell mobilization and collection as defined as number of days to reach a CD34+ cell dose of 2 x 10(6) per kg should not be used independently to forecast posttransplantation prognosis, engraftment, DFS, and OS.

Mobilization of peripheral blood stem cells in CLL patients after front-line fludarabine treatment

Autologous peripheral blood stem cell transplantation is performed in an increasing number of chronic lymphocytic leukaemia (CLL) patients who are in the first remission following fludarabine treatment. There are contradictory data about the adverse impact of fludarabine on stem cell harvest. We analysed retrospectively mobilization results in 56 poor-risk CLL patients (median age: 56 years) who underwent first-line treatment with fludarabine and cyclophosphamide. The mobilization, consisting of cyclophosphamide 3 g/m(2) and granulocyte colony-stimulating factor (G-CSF) 10 microg/kg per day, was performed with a median of 77 days following the last fludarabine course. The target yield was >or=2.0x10(6) CD34+ cells/kg. The procedure was successful in 23 (41%) patients. A median of 3.3x10(6) CD34+ cells/kg was collected per patient. The successful mobilization was associated with a longer interval from the last chemotherapy (>2 months). The mobilization result was not influenced by the number of fludarabine cycles. No correlation was found in other parameters such as disease stage at diagnosis, disease status at stimulation or age. The poorly mobilized patients had significantly lower prestimulation blood counts (platelets, WBC and haemoglobin). Our data show that fludarabine does not generally prevent the stem cell mobilization; nevertheless, mechanisms related to the impact of fludarabine on stem cell harvest must be further investigated.

Factors for PBPC collection efficiency and collection predictors

Factors affecting collection efficiency of peripheral blood stem cells (PBSCs) include patient's age, diagnosis, preceding chemoradiotherapy, disease invasion of the bone marrow and mobilizing chemotherapy in PBSC collection for autologous transplants. Mobilizing cytokines, timing for apheresis, machines and operating software would affect mobilization and collection of PBSCs both for autologous and allogeneic transplantation. Also donor's age and gender would affect PBSC yield for allogeneic transplantation. Surrogate markers including peripheral blood CD34+ cell counts before mobilization and on day of collection have been reported to predict the yield of PBSC harvest. A number of standard procedures have been developed based on these findings. Newer agents for PBSC mobilization are being evaluated and still other factors affecting mobilization are being sought to better predict and cope with poor mobilization.

High-dose treosulfan in patients with relapsed or refractory high-grade lymphoma receiving tandem autologous blood stem cell transplantation

This phase I/II study evaluated high-dose treosulfan in patients with high-grade lymphoma. In all, 21 patients (median age 51, 25-60 years) with primary refractory disease (n=3) or early (n=11) or late (n=7) relapse received DexaBEAM and one course etoposide for cytoreduction and PBPC mobilization. Subsequently, 16 patients received 30 g/m2 treosulfan and 140 mg/m2 melphalan, followed by autologous transplantation. Nine patients received a 2nd high-dose treatment (HDT) with 30 g/m2 treosulfan and 750 mg/m2 thiotepa. Recovery time to >1/nl leukocytes and >25/nl thrombocytes was 8.9 (range 8-11) and 11.9 (8-16) days after 1st and 9.6 (7-13) and 13 (9-19) days after 2nd HDT. Reversible grade 3 or 4 nonhematologic toxicities included mucositis (n=7), infection (n=7) and one episode of re-entry tachycardia. Two treatment-related deaths occurred after 2nd HDT. Since three dose-limiting toxicities occurred among nine patients receiving tandem HDT, 30 g/m2 of treosulfan was considered MTD in this setting. Patients with late compared to early relapse or refractory disease had a higher probability of CR (6/7 vs 3/14 patients, P=0.017) and overall survival (71 vs 21%, P<0.05, 24-49 months follow-up). In conclusion, high-dose treosulfan as major therapy component induces sustained complete remissions in relapsed high-grade lymphoma with acceptable toxicity.

The role of diagnosis in patients failing peripheral blood progenitor cell mobilization

BACKGROUND

Failure to mobilize PBPCs for auto-logous transplantation has mostly been attributed to previous therapy and poses therapeutic problems.

STUDY DESIGN AND METHODS

The role of underlying disease was analyzed in 17 of 73 (23%) patients with PBPC mobilization failure, and secondary mobilization with high-dose filgrastim was attempted.

RESULTS

Of 16 patients with acute leukemia, 13 (81%) mobilized poorly. In contrast, of 57 patients with non-Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, and solid tumor, 53 (93%, p < 0.001) showed good PBPC mobilization. Relapsed disease did not predispose to poor mobilization. As secondary mobilization attempt, 7 patients received 25 micro g per kg per day filgrastim without chemotherapy leading to a 3.7 +/- 2.8-fold (SD) increase in the maximum number of circulating CD34+ cells (p = 0.104). PBPC apheresis yielded 3.3 (+/-0.5) x 10(6) CD34+ cells per kg of body weight in 5 patients. Four poor mobilizers received 50 micro g per kg per day filgrastim as second or third mobilization attempt. Circulating CD34+ cells in these patients increased by 1.5 (+/-0.7) compared with the primary G-CSF application.

CONCLUSION

Selective PBPC mobilization failure was seen in patients with acute leukemia whereas remarkably good mobilization was seen in other malignancies. Increasing the filgrastim dose to 25 micro g per kg per day may allow PBPC collection in patients failing PBPC mobilization.

Impact of chemotherapy regimen and hematopoietic growth factor on mobilization and collection of peripheral blood stem cells in cancer patients

Various chemotherapy regimens, combined with recombinant human granulocyte colony-stimulating factor(rhG-CSF) or recombinant granulocyte-macrophage CSF (rhGM-CSF) are used in cancer patients to mobilize and collect peripheral blood stem cells (PBSC). In this retrospective study, we evaluated and compared the efficacy of such regimens in 262 patients with different types of malignant diseases. The following chemotherapy regimens were applied: ifosfamide-etoposide-cisplatin or bleomycin (n = 96; mainly patients with testicular cancer); ifosfamide-etoposide plus or minus cytosine arabinoside (Ara-C) or vincristine (VCR)(n = 52; mainly patients with lymphoma); cyclophosphamide-anthracycline (n = 53; mainly patients with breast cancer); intermediate to high dose (ID-HD) cyclophosphamide (n = 37; mainly patients with breast or ovarian cancer. or multiple myeloma; and others (n = 24). rhG-CSF or rhGM-CSF, each at an average daily dose of 5 microg/kg body weight, were used in 166 and 96 patients, respectively. The study evaluated and compared the efficacy of these two cytokines. In patients receiving rhG-CSF, CD34+ cells could be collected earlier (median: day 14 versus day 16) and there was a significantly higher white blood cell count (WBC)(median 11,350 versus 5550/microl) and CD34+ cell count (median 88 versus 43/microl) at the start of apheresis, and a significantly higher CD34+ cell yield (median 7.4 x 10(6) versus 4.6 x 10(6)/kg) than in patients who receivedrhGM-CSF. Among the various chemotherapeutic regimens used, each combined with rhG-CSF, ifosfamide-etoposide plus or minus Ara-C or VCR mobilized a significantly higher number of CD34+ cells (median 119/microl) and produced a significantly higher harvest of these cells (median 13 x 10(6)/kg) than cyclophosphamide-anthracycline (median 87/microl and 7 x 10(6)/kg, respectively) or ID-HD cyclophosphamide (median 59/microl and 5 x I 0(6)/kg, respectively). Ifosfamide-etoposide plus or minus Ara-C or VCR was also superior to ifosfamide-etoposide-cisplatin or bleomycin (median 78/microl and 9 x 10(6)/kg, respectively), but at borderline significance. The outcome of PBSC mobilization and collection appeared to be negatively influenced by the number of relapses before the current salvage treatment. These data indicate that mobilization and collection of PBSCstrongly depend on the type of hematopoietic growth factor and chemotherapeutic regimen used. The data further show rhG-CSF is a more effective growth factor than rhGM-CSF and ifosfamide-etoposide-based regimens, particularly ifosfamide-etoposide plus or minus Ara-C or VCR, are highly effective regimens in mobilizing and collecting CD34+ cells.

A multivariable analysis of factors influencing mucositis after autologous progenitor cell transplantation

Mucositis is a common and vexing complication of autologous progenitor cell transplantation (ABMT). A modified oral mucositis assessment scale (OMAS) has been found to be a reproducible and effective tool for monitoring mucositis after radiation therapy or chemotherapy. We utilized the modified OMAS scale to study clinical parameters associated with the development of mucositis in 79 patients undergoing ABMT. Median patient age was 52; 61% had non-Hodgkin's lymphoma (NHL), 23% multiple myeloma and 14% Hodgkin's disease. Patients were mobilized with G-CSF alone or the combination of etoposide plus G-CSF. Univariable correlates of worse mucositis were prior radiation therapy (P = 0.004), a diagnosis of NHL (P = 0.014), progenitor cell mobilizing regimen containing etoposide (P = 0.001), and ABMT preparative regimen containing etoposide (P = 0.006). Multivariable regression analysis revealed that NHL diagnosis (P = 0.007), prior radiation therapy (P = 0.001), and etoposide in the mobilizing regimen (P = 0.034) were associated with worse post-transplant mucositis. Worsening mucositis correlated with a longer inpatient length of stay. We conclude that several variables contribute to worsening mucositis during autologous transplantation, including etoposide in the progenitor cell mobilizing regimen.

The efficacy of prophylactic outpatient antibiotics for the prevention of neutropenic fever associated with high-dose etoposide (VP-16) for stem cell mobilization

High-dose etoposide (2 g/m(2)) plus G-CSF is a very effective regimen for peripheral blood progenitor cell (PBPC) mobilization. Unfortunately, neutropenia is common. The infectious complications associated with high-dose etoposide have not been previously described. After noting a high incidence of hospitalizations for neutropenic fever, we began a vigorous prophylactic antibiotic regimen for patients receiving high-dose etoposide plus G-CSF, attempting to reduce infectious complications. Ninety-eight patients underwent etoposide mobilization between December 1997 and June 2000. Three chronological patient groups received: (1) no specific antibiotic prophylaxis (n = 44); (2) vancomycin i.v., cefepime i.v., clarithromycin p.o., and ciprofloxacin p.o. (n = 27); and (3) vancomycin i.v., clarithromycin p.o., and ciprofloxacin p.o. (n = 27). The patients not receiving antibiotic prophylaxis had a 68% incidence of hospitalization for neutropenic fever. In the patients receiving prophylaxis, the incidence was reduced to 26% and 15% respectively, for an overall incidence of 20% (P < 0.001 for comparison between prophylaxed and unprophylaxed groups). We conclude that etoposide mobilization is associated with a significant incidence of neutropenic fever, which can be substantially reduced by a vigorous antimicrobial prophylactic program.

Simultaneous administration of G-CSF and GM-CSF for re-mobilization in patients with inadequate initial progenitor cell collections for autologous transplantation

BACKGROUND

A proportion of candidates for high-dose chemotherapy with autologous PBPC support (HDC-PBPCS) will not provide an adequate PBPC yield from their first mobilization. The value of re-mobilization and the best regimen for re-mobilization in these patients is unclear.

METHODS

In 23 patients who failed to provide > or = 3 x 10(6) CD34+ cells/kg after their first mobilization, PBPC were re-mobilized using a regimen of simultaneous administration of G-CSF and GM-CSF (10 microg/kg/day each) with leukaphereses (LP) starting Day 4 or 5 of CSF administration. Yields of WBC/kg, MNC/kg and CD34+ cells/kg/L of processed blood were compared between the first and second mobilization in each patient. The ability of the combined yield from the two mobilizations to achieve the desired threshold PBPC yield and the tolerability of the re-mobilization were determined.

RESULTS

The re-mobilization regimen was well-tolerated and no patient discontinued the regimen because of toxicity. Median collected WBC/kg/L (1.37 x 10(7) versus 2.62 x 10(7), p = 0.0065), MNC/kg/L (0.77 x 10(7) versus 1.97 x 10(7), p = 0.0003), CD34+ cells/kg/L (1.64 x 10(7) versus 4.18 x 10(7), p = 0.001) were significantly higher after the second mobilization (G-CSF/GM-CSF combination). Percentage of CD34+ cells in the leukapheresis was also significantly higher after the second mobilization (median 0.104% versus 0.195%, p = 0.036). Twelve of 22 patients achieved the target PBPC dose (> 3 x 10(6)/CD34+ cells/kg) after two mobilizations (six patients achieved the target from the second mobilization alone). A further eight underwent HDC-PBPCS without achieving the target PBPC dose. These patients experienced a significant delay in neutrophil and platelet engraftment when compared with those patients achieving the target dose.

DISCUSSION

This study demonstrates that the combination of G-CSF and GM-CSF is an effective and tolerable method for re-mobilization of PBPC in patients who fail to provide an adequate yield from their first mobilization.

Kinetics of standardized large volume leukapheresis (LVL) in patients do not show a recruitment phenomenon of peripheral blood progenitor cells (PBPC)

Although several studies have demonstrated the efficacy of large volume leukapheresis (LVL) to yield high numbers of peripheral blood progenitor cells (PBPC), the mechanisms of stem cell release into circulation and the postulated phenomenon of PBPC recruitment during apheresis have not been investigated in detail. Therefore, we analyzed the kinetics of stem cell enrichment in a total of 34 standardized LVL for patients with hematologic malignancies (lymphoma, multiple myeloma) and solid tumors (breast cancer, rhabdomyosarcoma). LVL was started 2 h after administration of G-CSF processing six times the patient's blood volume. Cells were sequentially collected into six bags and the numbers of leukocytes, mononuclear cells (MNC), CD34+ cells and colony-forming cells (CFU-GM) in each collection bag were analyzed. The numbers of PBPC collected demonstrated a continuous decrease starting after an early maximum during the second processed blood volume (P = 0.001). Interestingly, these kinetics of decreasing stem cell yields during LVL were similar for both entities of patients with hematologic malignancies as well as for both groups of patients with solid tumors. In summary, a recruitment phenomenon, defined as a time-dependent and LVL-induced increase of PBPC, could not be demonstrated in any of the diseases investigated.

Ifosamide, epirubicin and granulocyte colony-stimulating factor: a regimen for successful mobilization of peripheral blood progenitor cells in patients with multiple myeloma

In general, the mobilization of peripheral blood progenitor cells (PBPC) in multiple myeloma (MM) patients is poor and is achieved in most cases by combined cyclophosphamide and G-CSF. This study was performed to examine the efficacy of combined ifosfamide/epirubicine and G-CSF for PBPC mobilization and purging. Sixteen patients suffering from multiple myeloma in stage II/A and III/A according to Durie and Salmon underwent chemotherapy consisting of a total of three cycles of ifosfamide (3 g/m(2) on days 1 and 2 and epirubicine 80 mg/m(2) on day 1) and G-CSF (10 or 20 microg/kg body weight (BW) daily until harvesting). PBPC harvesting was performed after the first and third cycle of chemotherapy. The median number of PBPC after the first cycle of chemotherapy was 7.79 x 10(6) CD34+ cells/kg BW (ranging from 0.94-26.36 x 10(6)) and 6.38 x 10(6) CD34+ cells/kg BW (ranging from 0.79-29.31 x 10(6)) after the third cycle of chemotherapy. Clinical re-evaluation after three cycles of chemotherapy showed 13 (81 per cent) patients in partial remission (PR), two (12 per cent) in complete remission (CR) and one (6.25 per cent) in stable disease (SD). No major side-effects were observed, six patients developed hematological toxicity stage IV WHO for a median of 3.9 days but no serious infection episodes occurred. Combined ifosfamide/epirubicin and standard G-CSF is able to mobilize sufficient PBPC without serious side-effects for patients with MM and for purging procedures resulting in a high proportion of complete remissions after tandem high-dose melphalan chemotherapy.

Mobilization of hematopoietic stem cells

Hematopoietic stem cell transplantation has been extensively exploited as a therapeutic and research modality and has revolutionized current patient care. At present, more and more medical centers use peripheral blood progenitor cells for transplantation by mobilizing hematopoietic stem cells from bone marrow to peripheral blood because of potential advantages of peripheral blood stem cell transplantation over bone-marrow transplantation. Different effective mobilization regimens have been developed recently with chemotherapeutic agents, hematopoietic growth factors or their combination. This article reviews current developments related to hematopoietic stem cell mobilization including the biology of hematopoietic stem cells, strategies for mobilization, management for mobilization failure, mechanisms of mobilization, and side effects during mobilization. Finally, the Initiation-Amplification-Emigration-Adaptation Model is proposed to help aid understanding of the mechanisms of hematopoietic stem cell mobilization and to stimulate development of novel and optimal mobilization strategies for patient care.