Mobilization of peripheral blood progenitor cells (PBPC) in patients undergoing chemotherapy followed by autologous peripheral blood stem cell transplant (SCT) for high risk breast cancer (HRBC).

We have determined the effect of delayed addition of G-CSF after chemotherapy on PBPC mobilization in a group of 30 patients with high risk breast cancer (HRBC) undergoing standard chemotherapy followed by high-dose chemotherapy (HDCT) and autologous SCT. Patients received FAC chemotherapy every 21 days followed by G-CSF at doses of 5 microg/kg/day starting on day +15 (groups 1 and 2) or +8 (group 3) after chemotherapy. PBPC collections were performed daily starting after 4 doses of G-CSF and continued until more than 2.5 x 10(6) CD34+ cells had been collected. In group 1, steady-state BM progenitors were also harvested and used for SCT. Groups 2 and 3 received PBPC only. The median number of collections was three in each group. Significantly more PB CD34+ cells were collected in patients receiving G-CSF starting on day 8 vs day 15 (9.43 x 10(6)/kg and 6.2 x 10(6)/kg, respectively) (P < 0.05). After conditioning chemotherapy all harvested cells including BM and PBPC were reinfused. Neutrophil and platelet engraftment was significantly faster in patients transplanted with day 8 G-CSF-mobilized PBPC (P < 0.05) and was associated with lower transplant related morbidity as reflected by days of fever, antibiotics or hospitalization (P < 0.05). Both schedules of mobilization provided successful long-term engraftment with 1 year post-transplant counts above 80% of pretransplant values. In conclusion, we demonstrate that delayed addition of G-CSF results in successful mobilization and collection of PBPC with significant advantage of day 8 G-CSF vs day 15. PBPC collections can be scheduled on a fixed day instead of being guided by the PB counts which provides a practical advantage. Transplantation of such progenitors results in rapid short-term and long-term trilineage engraftment.     

Ex vivo expanded unselected peripheral blood: progenitor cells reduce posttransplantation neutropenia, thrombocytopenia, and anemia in patients with breast cancer

The safety and efficacy of administering ex vivo expanded peripheral blood progenitor cells (PBPC) to patients with breast cancer who undergo high-dose chemotherapy and PBPC transplantation was investigated. Unselected PBPC were cultured in gas-permeable bags containing 1-L serum-free media, granulocyte colony-stimulating factor, stem cell factor, and pegylated megakaryocyte growth and development factor for 9 days. Cell dose cohorts were assigned to have between 2 and 24 x 10(9) PBPC cultured at 1, 2, or 3 x 10(6) cells/mL. Twenty-four patients received high-dose chemotherapy followed by infusion of the cultured PBPC and at least 5 x 10(6) CD34(+) uncultured cryopreserved PBPC per kilogram. No toxicities resulted from infusions of the ex vivo expanded PBPC. The study patients had shorter times to neutrophil (P =.0001) and platelet (P =.01) recovery and fewer red cell transfusions (P =.02) than 48 historical controls who received the same conditioning regimen and posttransplantation care and at least 5 x 10(6) CD34(+) PBPC per kilogram. Improvements in all these endpoints were significantly correlated with the expanded cell dose. Nine of 24 (38%) patients recovered neutrophil counts above 500/microL by day 5 or 6 after transplantation, whereas none of the controls had neutrophil recovery before the eighth day. Seven (29%) patients had neutropenia for 3 or fewer days, and 9 (38%) patients did not experience neutropenic fevers or require broad-spectrum antibiotics. Therefore, ex vivo expanded PBPC are capable of ameliorating posttransplantation neutropenia, thrombocytopenia, and anemia in patients receiving high-dose chemotherapy.     

Selection and expansion of peripheral blood CD34+ cells in autologous stem cell transplantation for breast cancer

Cytopenia after high-dose chemotherapy and autologous stem cell reinfusion is a major cause of morbidity. Ex vivo cultured expansion and differentiation of CD34+ peripheral blood progenitor cells (PBPC) to neutrophil precursors may shorten the neutropenic period further. We explored the use of these ex vivo cultured PBPCs in nine patients with metastatic breast cancer. All underwent PBPC mobilization with cyclophosphamide, VP-16, and G-CSF. Subsequently, they underwent four to five apheresis procedures. One apheresis product from each patient was prepared using the Isolex 300 Magnetic Cell Separation System (Baxter Immunotherapy, Irvine, CA) to obtain CD34+ cells. These cells were then cultured in gas permeable bags containing serum-free X-VIVO 10 (BioWhittaker, Walkersville, MD) medium supplemented with 1% human serum albumin and 100 ng/mL PIXY321. At day 12 of culture the mean fold expansion was 26x with a range of 6 to 64x. One patient's cells did not expand because of a technical difficulty. The final cell product contained an average of 29.3% CD15+ neutrophil precursors with a range of 18.5% to 48.1%. The patients underwent high-dose chemotherapy with cyclophosphamide, carboplatin, and thiotepa. On day 0, the cryopreserved PBPCs were reinfused and on day +1 the 12-day cultured cells were washed, resuspended, and reinfused into eight of nine patients. One patient was not infused with cultured cells. The mean number of cultured cells reinfused was 44.6 x 10(6) cells/kg with a range of 0.8 to 156.6 x 10(6) cells/kg. No toxicity was observed after reinfusion. The eight patients have recovered absolute neutrophil counts > 500/microL on a median of 8 days (range 8 to 10 days); the median platelet transfusion independence occurred on day 10 (range 8 to 12 days) and platelet counts > 50,000/microL were achieved by day 12 (range 9 to 14) for the seven patients whose platelet counts could be determined. Expanded CD34+ selected PBPC can be obtained and safely reinfused into patients.     

Stem cell mobilization with G-CSF alone in breast cancer patients: higher progenitor cell yield by delivering divided doses (2 x 5 microg/kg) compared to a single dose (1 x 10 microg/kg)

We investigated the schedule dependency of G-CSF (10 microg/kg) alone in mobilizing peripheral blood progenitor cells (PBPC) in breast cancer patients. After a median of three cycles (range, 2-6) of anthracycline-based chemotherapy, 49 patients with breast cancer (stage II/III, > or = 10+ Ln n = 36; locally advanced/inflammatory n = 8, stage IV (NED) n = 5) underwent PBPC collection after steady-state mobilization either with 1 x 10 microg/kg (n = 27) or with 2 x 5 microg/kg (n = 22) G-CSF daily for 4 consecutive days until completion of apheresis. Apheresis was started on day 5. Priming with 2 x 5 microg/kg resulted in a higher median number of CD34+ cells (5.8 vs 1.9 x 10(6)/kg, P = 0.003), MNC (6.6 vs 2.6 x 10(8)/kg, P < 0.001) and CFU-GM (6.5 vs 1.3 x 10(4)/kg, P = 0.001) in the first apheresis than with 1 x 10 microg/kg. Also the overall number of collected BFU-E was higher in the 2 x 5 microg group (9.2 vs 3.1 x 10(4)/kg; P = 0.01). After high-dose chemotherapy with cyclophosphamide/thiotepa/mitoxantrone (n = 46) hematopoietic engraftment with leukocyte count > 1.0/nl was reached in both groups after a median of 10 days (range, 8-15) and with platelets count > 50/nl after 12 (range, 9-40) and 13 days (range, 12-41), respectively. A threshold of > 2.5 x 10(6)/kg reinfused CD34+ cells ensured rapid platelet engraftment (12 vs 17 days; P = 0.12). Therefore, the target of collecting > 2.5 x 10(6) CD34+ cells was achieved in 21/27 (80%) patients of the 1 x 10 microg group and in 21/22 (95%) patients of the 2 x 5 microg/kg group with a median of two aphereses (range, 1-4). None in the 10 microg/kg group, but 6/22 (28%) patients in the 2 x 5 microg/kg group required only one apheresis procedure, resulting in fewer apheresis procedures in the 2 x 5 microg/kg group (mean, 1.8 vs 2.3, P = 0.01). These results demonstrate that priming with 10 microg/kg G-CSF alone is well tolerated and effective in mobilizing sufficient numbers of CD34+ cells in breast cancer patients and provide prompt engraftment after CTM high-dose chemotherapy. G-CSF given 5 microg/kg twice daily (2 x 5 microg) leads to a higher harvest of CD34+ cells and required fewer apheresis procedures than when given 10 microg/kg once daily (1 x 10 microg).     

High-dose therapy and peripheral blood progenitor cell transplantation: effects of recombinant human granulocyte-macrophage colony-stimulating factor on the autograft

Between June 1989 and June 1992, 144 patients participated in sequential clinical trials using peripheral blood progenitor cells (PBC) as their sole source of hematopoietic rescue following high-dose chemotherapy. All patients had received prior extensive combination chemotherapy and had marrow defects that precluded autologous bone marrow transplantation (ABMT). PBC were collected according to a single apheresis protocol. The initial 86 patients (group 1) had PBC collected without mobilization. Beginning in April 1991, PBC were mobilized solely with recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF). Thirty-four patients (group 2) received rHuGM-CSF at a dose of 125 micrograms/m2/d by continuous intravenous infusion, and 24 patients (group 3) received rHuGM-CSF at a dose of 250 micrograms/m2/d by continuous intravenous infusion. Patients underwent at least six aphereses and had a minimum of 6.5 x 10(8) mononuclear cells (MNC)/kg collected. Cytokines were not routinely administered immediately after transplantation. A median of nine aphereses were required to collect PBC in group 1 and seven aphereses for groups 2 and 3 (P = .03). The time required to recover 0.5 x 10(9)/L granulocytes after transplant was significantly shorter (P = .0004) for the mobilized groups; the median time to recovery was 26 days for group 1, 23 days for group 2, and 18 days for group 3. Transplantation of PBC mobilized with rHuGM-CSF resulted in a shorter time to platelet (P = .04) and red blood cell (P = .01) transfusion independence. Mobilization with rHuGM-CSF alone resulted in efficient collection of PBC, that provided rapid and sustained restoration of hematopoietic function following high-dose chemotherapy. Mobilization of PBC with rHuGM-CSF alone is an effective method for patients who have received prior chemotherapy and have bone marrow abnormalities.     

A randomised study comparing peripheral blood progenitor mobilisation using intermediate-dose cyclophosphamide plus lenograstim with lenograstim alone

We conducted a prospective randomised study to compare the efficiency of out-patient progenitor cell mobilisation using either intermediate-dose cyclophosphamide (2 g/m(2)) and lenograstim at 5 micrograms/kg (Cyclo-G-CSF group, n=39) or lenograstim alone at 10 micrograms/kg (G-CSF group, n=40). The end points were to compare the impact of the two regimens on mobilisation efficiency, morbidity, time spent in hospital, the number of apheresis procedures required and engraftment kinetics. Successful mobilisation was achieved in 28/40 (70%) in the G-CSF group vs 22/39 (56.4%) for Cyclo-G-CSF (P=0.21). The median number of CD34+ cells mobilised was 2.3 x 10(6)/kg and 2.2 x 10(6)/kg for G-CSF and cyclo-G-CSF arms following a median of two apheresis procedures. Nausea and vomiting and total time spent in the hospital during mobilisation were significantly greater after Cyclo-G-CSF (P<0.05). Rapid neutrophil and platelet engraftment was achieved in all transplanted patients in both groups. In conclusion, G-CSF at 10 micrograms/kg was as efficient at mobilising progenitor cells as a combination of cyclophosphamide and G-CSF with reduced hospitalisation and side effects and prompt engraftment. When aggressive in-patient cytoreductive regimens are not required to both control disease and generate progenitor cells, the use of G-CSF alone appears preferable to combination with intermediate-dose cyclophosphamide.     

Mobilization kinetics of peripheral blood progenitor cells after IAPVP-16 salvage chemotherapy plus G-CSF in lymphoproliferative disorders

We have explored the efficacy of salvage chemotherapy combination, IAPVP-16 (ifosfamide 5 g/m2 on day 1; VP-16 100 mg/m2 on days 1-3; ara-C 1.2 g/m2/12 h on days 1 and 2; methylprednisolone 80 mg/m2 on days 1-5) plus G-CSF for PBPC mobilization. This protocol was used in 45 patients with relapsed or refractory lymphoproliferative diseases who underwent 85 leukaphereses. In 41 patients > 2 x 106/kg CD34+ cells were obtained after a median of two procedures. The median number of CD34+ cells harvested was 3.2 x 106/kg per apheresis and 8.4 x 106/kg per patient. Seven of 10 patients who had failed previous mobilization attempts achieved more than 2 x 106 CD34+ cells/kg in a maximum of three aphereses. A history of previous mobilization failure and a low platelet count (<150 x 109/l) negatively influenced the CD34+ cell yield in univariate and multivariate analyses. A good correlation was found between the circulating CD34+ cells/microl and the CD34+ cells and CFU-GM in the leukaphereses products (r = 0.93 and r = 0.73, P < 0.001), and > or =17 CD34+ cells/microl predicted the achievement of > 2 x 106/kg CD34+ cells in a single leukapheresis in more than 90% of cases. IAPVP-16 plus G-CSF may be specially indicated in tandem transplantations or CD34+ selection and in patients who have failed previous mobilization attempts.     

Immunohistochemical detection of breast cancer cells in paired peripheral blood progenitor cell specimens collected after cytokine or cytokine and myelosuppressive chemotherapy.

Mobilized peripheral blood progenitor cells (PBPC) from 30 patients with advanced breast cancer were studied for the presence of tumor cell contamination using a highly sensitive immunohistochemical technique with the capacity to detect one tumor cell in one million mononuclear cells. Aliquots of PBPC were obtained after 4 days of G-CSF and/or GM-CSF and again during G-CSF-stimulated recovery from myelosuppressive doses of cyclophosphamide. The overall incidence of tumor cell contamination was 23%, occurring in PBPC specimens from seven of 30 patients. All four cases in which tumor cells were detected after mobilization with cytokine alone also had tumor cells detected in PBPCs collected following chemotherapy and G-CSF. There were three cases in which malignant contamination was detected only in the specimens collected after cyclophosphamide. There was a greater frequency of tumor cell contamination in aphereses performed during G-CSF-stimulated recovery from cyclophosphamide than in collections primed by cytokine alone (13% vs 23%; P = 0.08), although this did not reach statistical significance. This trend suggests that collection of PBPC during cytokine-stimulated recovery from myelosuppressive chemotherapy may be associated with a greater risk of contamination with malignant cells than apheresis during mobilization with cytokines in the steady state.     

Very large amounts of peripheral blood progenitor cells eliminate severe thrombocytopenia after high-dose melphalan in advanced breast cancer patients

We analyzed the relationship between the reinfusion of large or very large amounts of peripheral blood progenitor cells (PBPC) and hematologic toxicity in twenty-one advanced breast cancer patients subjected to a myeloablative dose of melphalan at the end of a high-dose sequential chemotherapy (HDSC) program. We also evaluated the influence of the white blood cell (WBC) count to predict an optimal PBPC harvest after high-dose chemotherapy and growth factor priming. Twenty-one patients with high-risk or metastatic breast cancer sequentially received: high-dose cyclophosphamide (HD-Cy) and G-CSF followed by PBPC harvest, HD-methotrexate plus vincristine, HD-doxorubicin, cisplatin and finally HD-melphalan 200 mg/m2 (HD-L-PAM) followed by PBPC reinfusion. No growth factor was administered after HD-L-PAM. CD34+ cytofluorimetric analysis, WBC count and clonogenic assays were employed to monitor circulating cells and to analyze the PBPC harvest. Correlation between different PBPC doses and hematologic toxicity as well as leukocyte and platelet recovery time was attempted. Patients received a median number of 16 (4-25.1) x 10(6)/kg CD34+ cells, 81.3 (30.8-228) x 10(4)/kg CFU-GM and 4.2 (1.3-7.3) x 10(8)/kg nucleated cells (NC) after HD-L-PAM. The number of days with fewer than 1 x 10(9)/l leukocytes and 20 x 10(9)/l platelets were 6 (range 4-9) and 0 (range 0-3), respectively. The CD34+ cell dose significantly correlated with both platelet count nadir (r = 0.73) and time to 50 x 10(9)/l platelets (r = 0.7), but did not correlate with time to reach more than 1 x 10(9)/l WBC count (r = 0.2). In particular, we found that in 12 patients given very large amounts of CD34+ cells, ranging between 15.8 and 25. 1 x 10(6)/kg (V-LA-CD34+), the platelet nadir count never fell below 20 x 10(9)/l and platelet transfusions were not required. Conversely, nine patients who received only large amounts of CD34+ cells, ranging between 4 and 12 x 10(6)/kg (LA-CD34+), experienced a platelet nadir lower than 20 x 10(9)/l and required 2 days (range 1-4) to achieve independence from platelet transfusions (P = 0.001 and P = 0. 0005). The requirement for packed red blood cells (RBC) was 1.5 vs 3 units in the V-LA-CD34+ and LA-CD34+ groups respectively (P = 0.063). The analysis of 44 PBPC collections demonstrated that 29 aphereses performed with a WBC count <20 x 10(9)/l yielded a mean of 312 +/- 43 x 10(6) CD34+ cells and 1831 +/- 201 x 10(4) CFU-GM, whereas 15 collections performed with WBC count >20 x 10(9)/l yielded 553 +/- 64 x 10(6) CD34+ cells and 3190 +/- 432 x 10(4) CFU-GM (P = 0.004). In conclusion, our data suggests that V-LA-CD34+ eliminates severe thrombocytopenia and platelet transfusion requirements in breast cancer patients subjected to HD-L-PAM, and higher PBPC collections seems to coincide with WBC count higher than 20 x 10(9)/l after HD-Cy and G-CSF mobilization. These results justify a prospective study to establish whether large doses of CD34+ cells result in significant clinical benefits.     

Single vs twice daily G-CSF dose for peripheral blood stem cells harvest in normal donors and children with non-malignant diseases

The optimal dose and schedule of G-CSF for mobilization of peripheral blood stem cells (PBSC) is not well defined. G-CSF mobilization was performed in a group of healthy donors and paediatric patients for autologous back-up before receiving allogeneic stem cell transplant. Seventeen consecutive subjects who received G-CSF at 5 microg/kg/dose twice daily (group A) were compared with a historical control group of 25 subjects who received a single daily dose of 10 microg/kg/day G-CSF (group B). Double blood volume apheresis for PBSC collection was started on day 5. G-CSF was continued and apheresis repeated until the targeted CD34+ cell dose was achieved. Both groups were comparable for sex, age, body weight and reason for PBSC collection. Over two-thirds of the subjects in both groups were less than 16 years of age. The G-CSF priming and apheresis were well tolerated. When the first day apheresis products were analyzed, group A resulted in significantly higher yield of total nucleated cells (5.91 vs 3.92 x 108/kg, P = 0. 013), mononuclear cells (5.73 vs 3.92 x 108/kg, P = 0.017), CD34+ cells (2.80 vs 1.69 x 106/kg, P = 0.049) and colony-forming units (107 vs 54 x 104/kg, P = 0.010) as compared with group B. We conclude that the two dose schedule is more efficient in mobilizing PBSC in normal donors and children with non-malignant diseases. This approach may reduce the number of aphereses required and thus reduce the transplant cost.     

COLLECTION AND TRANSPLANTATION OF PERIPHERAL BLOOD PROGENITOR CELLS MOBILIzED BY G-CSF ALONE IN CHILDREN WITH MALIGNANCIES

Results of collection and transplantation of peripheral blood progenitor cells (PBPC) mobilized by G-CSF in 31 children with different malignancies were analysed. A total of 43 aphereses were performed, following administration of granulocyte colony-stimulating factor (G-CSF), using a continuous flow blood cell separator (Cobe Spectra) through a central venous catheter. For patients weighing ≤25 kg the extracorporeal line was primed with red blood cells. The mean blood flow rate was 33.2ml/min (range 12–56ml/min). The mean number of mononuclear cells (MNC), granulocyte-macrophage colony-forming units (CFU-GM) and CD34⁺ cells collected were 7.22×10⁸/kg body weight (b.w.), 15.9×10⁴/kg and 5.44×10⁶/kg respectively.
The morbidity related to PBPC collection was low and the mean apheresis time was 302.7min (range 115–492). The volume of processed blood for apheresis (per kilogram body weight) ranged from 117 to 539.6 (mean 309.13ml/kg). 20 patients required only one apheresis to collect the minimum requirement of 5–7×10⁸/kg of MNC.
All patients subsequently underwent autografting with PBPC after myeloablative therapy. Days to achieve an absolute count of neutrophils (ANC) <0.5×10⁹/l and a platelet count of 20×10⁹2/l without platelet support were 9.5 and 18, respectively. The number of CD34⁺ cells infused correlated highly with engraftment kinetics. The extramedullary toxicity was low and manageable.     

Peripheral Blood Progenitor Cell Collection during Hematopoietic Recovery following Autologous Blood Progenitor Cell Transplantation

Background and objectives: Peripheral blood progenitor cells (PBPC) are increasingly used for autologous transplantation after high-dose radio/chemotherapy in patients suffering from cancer. PBPC are usually collected after mobilization with conventional-dose chemotherapy plus growth factor. However, it is conceivable to perform leukapheresis for the second autograft during recovery of hematopoiesis after the first course of HDCT/ABPCT. Materials and methods: We treated two patients this way. In the first, with germ cell cancer, six 12-liter leukaphereses yielded 1.8×10⁶ CD34+ cells/kg after mobilization with cis-platinum, etoposide and ifosfamide (PEI) plus granulocyte colony-stimulating factor (G-CSF). The second patient, with relapsed Hodgkin's disease, underwent PBPC collection after treatment with dexamethasone, carmustine, etoposide, cytarabine and melphalan (DexaBEAM) plus G-CSF. Due to excellent mobilization, 8.5×10⁶ CD34+ cells/kg were collected by one 12-liter leukapheresis. Both patients then underwent PBPC collection during hematopoietic recovery following HDCT and ABPCT. Results: In patient 1, following HDCT and ABPCT, three 12-liter aphereses resulted in 0.7×10⁶ CD34+ cells/kg. In patient 2, also after HDCT and ABPCT, a second autograft with 3.2×10⁶ CD34+ cells/kg was harvested by a single 10-liter apheresis. No adverse effects were seen in either patient during apheresis following ABPCT. To our knowledge this is the first report dealing with PBCT collection during hematopoietic recovery following HDCT and ABPCT. Conclusions: (1) PBPC harvesting is feasible and well tolerated in this setting. (2) In appropriate patients with efficient PBPC mobilization after conventional-dose chemotherapy, a further PBPC autograft can be collected during recovery of hematopoiesis after ABPCT, serving as a rescue for a second course of HDCT.     

Successful mobilization of peripheral blood stem cells in heavily pretreated myeloma patients with G-CSF alone

 We investigated the feasibility of mobilizing peripheral blood stem cells (PBSC) with G-CSF alone in 24 patients with multiple myeloma. The median age was 53 years (range 33–62). All patients had stage II/III disease and responded to standard first-line (n=6) or salvage chemotherapy (n=18). The median number of previous chemotherapy cycles was 7 (4–18) and the median number of prior melphalan-cycles was 6 (0–14). Nine (35%) patients had experienced prior radiation therapy. The patients received either 10 μg/kg G-CSF (n=18) or 24 μg/kg G-CSF (n=7, including one patient with previous 10 μg/kg G-CSF stimulation) daily s.c. for 5 or more consecutive days until completion of harvesting, starting apheresis on the fifth day. G-CSF treatment was well tolerated, with only slight bone pain in half of the patients (51%). After a median of three (range 1–7) apheresis procedures, medians of 3.8 (0.3–17)×10⁶ CD34+ cells/kg, 8.5 (4.5–24)×10⁸ MNC/kg, 2.9 (0.6–39.4)×10⁴ CFU-GM/kg, and 5.6 (0.9–49)×10⁴ BFU-E/kg were harvested. Three patients (12%) with extensive melphalan pretreatment failed the target collection of at least 2.0×10⁶ CD34+ cell/kg. Pretreatment with six or more cycles of melphalan yielded a smaller number of CD34+ cells than pretreatment with fewer than six cycles (2.5 vs 5.3×10⁶/kg;p=0.001). Nineteen patients underwent high-dose chemotherapy consisting of either total marrow irradiation (9 Gy)/busulfan (12 mg/kg) and cyclophosphamide (120 mg/kg) (n=10), or busulfan (14 mg/kg)/cyclophosphamide (120 mg/kg) (n=5), or tandem melphalan (200 mg/m²). The median time for granulocyte (>1.0/nl) and platelet (>50/nl) recovery was 10 and 14 days (ranges 7–12 and 8–40), respectively. G-CSF alone is a safe, alternative approach to mobilizing sufficient PBSC in patients with multiple myeloma and allows an exact prediction of harvest time. G-CSF-mobilized PBSCs ensure rapid engraftment after myeloablative therapy. Melphalan treatment should be avoided in patients who are candidates for high-dose chemotherapy. Received: February 5, 1998 / Accepted: April 14, 1998     

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.     

A randomized,multicenter study of G-CSF starting on day +1 vs day +5 after autologous peripheral blood progenitor cell transplantation

In order to assess the effect of delaying G-CSF administration after autologous peripheral blood progenitor cell (PBPC) transplantation on the duration of neutropenia, 87 patients were randomized to receive G-CSF 5 microg/kg/day starting on day +1 (n = 45) or +5 (n = 42) following PBPC transplantation, until recovery of the neutrophils. The duration of neutropenia (<0.5 x 10(9)/l) was shorter in the day +1 group (7 vs 8 days; P = 0.02), especially in patients receiving melphalan 200 mg/m(2) and CD34(+) cell doses >3.0 x 10(6)/kg. These patients had a later onset of neutropenia after transplant. There were no differences in time to neutrophil and platelet engraftment, or in the incidence of fever and documentation of infection. Although the duration of antibiotic therapy (7 vs 10.5 days; P = 0.01) and time to hospital discharge (13 vs 15 days; P = 0.02) were shorter in the day +1 group, these differences could not be predicted by the day of G-CSF initiation in multivariate analysis. Starting G-CSF on day +1 does not result in faster neutrophil engraftment but in later onset and consequently, slightly shorter duration of neutropenia in patients who receive melphalan 200 mg/m(2) and CD34(+) cell doses >3.0 x 10(6)/kg.     

Consolidation treatment with autologous peripheral blood progenitor cell transplantation in acute myeloid leukemia: a single center experience

Several trials have suggested that intensive post-remission therapy may prolong the duration of complete remission (CR) in acute myeloid leukemia (AML). The purpose of this study was to evaluate the feasibility and the efficacy of high-dose cytarabine (HiDAC) consolidation chemotherapy followed by high-dose therapy and autologous infusion of peripheral blood progenitor cells (PBPC) mobilized by G-CSF in adult patients with AML in first CR. Fifteen consecutive AML patients underwent HiDAC consolidation chemotherapy, used as a method of in vivo purging, followed by G-CSF for the purpose of autologous PBPC collection. Eleven patients collected a median of 6.9x10(8)/kg peripheral blood mononuclear cells (MNC) (range 2.9-23) and a median of 6.67x10(6)/kg CD34+ cells (range 1.8-33.5) with a median of two aphereses (range 1-3). Two patients did not mobilize and two obtained an inadequate number of progenitor cells. The 11 patients with adequate collections received myeloablative chemotherapy followed by the infusion of PBPC. The median number of days to recover neutrophils and platelets was 12 and 13, respectively. After a median follow-up of 28.7 months (range 17.2-43.4), five out of 11 patients who underwent PBPC transplantation are still in CR, five have died in first relapse and one is alive in CR after relapse treated with salvage therapy and second PBPC infusion. These results demonstrate that HiDAC consolidation chemotherapy followed by autologous PBPC transplantation is a feasible procedure with minimal toxicity. Randomized studies should be performed to evaluate whether this form of consolidation may produce a significant improvement in leukemia-free survival.     

Long-term hematopoietic engraftment after autologous peripheral blood progenitor cell transplantation in pediatric patients: effect of the CD34+ cell dose

BACKGROUND AND OBJECTIVES: We analyzed the relationship between long-term hematopoietic recovery and the number of CD34+ cells infused in order to determine the optimal dose of CD34+ cells for rapid and stable engraftment. PATIENTS AND METHODS: Between November 1993 and December 1998, 96 consecutive autologous transplantations were performed in 92 pediatric patients with different malignancies. Peripheral blood progenitor cells (PBPC) were mobilized by G-CSF alone (12 microg/kg/day s.c., Neupogen((R)); Amgen, Thousand Oaks, Calif., USA) and collected using a Cobe Spectra blood cell separator (Cobe, Denver, Colo., USA) through a central venous catheter with double lumen. The CD34+ cell contents of apheresis products were assessed by means of flow-cytometric analysis using an Epics Elite flow cytometer (Coulter, USA). RESULTS: The median number of CD34+ cells infused was 3.2 x 10(6)/kg (range 0.17-44.4). The median times for short-term engraftment (neutrophil count >0.5 x 10(9)/l and platelet count >20 x 10(9)/l) was 9 (range: 7-16) and 13 days (range: 7-91), respectively. The median times for long-term engraftment (platelet count >50 x 10(9)/l and >100 x 10(9)/l) was 21 (range: 10-249) and 45 days (range: 12-288). When the infused CD34+ cell dose was >/=5 x 10(6)/kg (median 7.99, range 5.01-44.4), there was a statistically significant increase in the rate of short- and long-term hematopoietic recovery compared to patients transplanted with a lower number of CD34+ cells (p < 0.0001). The earlier recovery in the high CD34+ cell group resulted in less transfusional support, fewer days on intravenous antibiotics and shorter hospitalization. CONCLUSIONS: This study confirms that G-CSF-mobilized PBPC provide rapid short- and long-term hematopoietic engraftment in pediatric patients undergoing autologous transplantation if a CD34+ cell dose >/=5.0 x 10(6)/kg is infused. As this PBPC dose seems to have clinical and potentially economic implications, it should be considered the optimal dose for apheresis.     

Recombinant human thrombopoietin (rhTPO) after autologous bone marrow transplantation: a phase I pharmacokinetic and pharmacodynamic study

Thrombocytopenia following myelotoxic therapy is a common problem and when severe (<20,000/microl) can lead to severe morbidity and mortality. Thrombopoietin (TPO) is a naturally occurring glycosylated peptide which stimulates the differentiation of bone marrow stem cells into megakaryocyte progenitor cells, induces the expression of megakaryocyte differentiation markers, promotes megakaryocyte proliferation, polyploidization and, ultimately, the formation of increased numbers of platelets in the circulation. TPO has now been produced by recombinant technology and has entered clinical trials. This open label phase I study was designed to determine the safety, tolerance and pharmacokinetics of recombinant thrombopoietin (rhTPO) when administered to patients after undergoing high-dose chemotherapy followed by autologous bone marrow transplantation. rhTPO was administered intravenously by bolus injection at doses ranging from 0.3 to 4.8 microg/kg/day every 3 days to 30 patients and 0.6 microg/kg daily to three patients. rhTPO was begun the day after marrow infusion and continued until platelet recovery to >20,000/microl. G-CSF was concomitantly administered to promote myeloid recovery. Serious adverse events or neutralizing antibodies to rhTPO were not observed during the study. Median platelet recovery after ABMT was 19 days (range, 11-41). Neither the dose nor the schedule of rhTPO appeared to have any impact upon the time course of platelet recovery. In this phase I study, rhTPO was found to be well tolerated without the development of neutralizing antibodies and without compromising neutrophil recovery. Platelet recovery was similar for all doses studied warranting further evaluation in phase II and III trials designed to test for platelet recovery efficacy.     

CD34+ selection of hematopoietic blood cell collections and autotransplantation in lymphoma: overnight storage of cells at 4 degrees C does not affect outcome

The purpose of this study was to investigate whether storing mobilized peripheral blood progenitor cell (PBPC) collections overnight before CD34+ selection may delay platelet count recovery after high-dose chemotherapy and CD34+-enriched PBPC re-infusion. Lymphoma patients underwent PBPC mobilization with cyclophosphamide 4 g/m2 i.v. and G-CSF 10 microg/kg/day subcutaneously. Patients were prospectively randomized to have each PBPC collection enriched for CD34+ cells with the CellPro CEPRATE SC System either immediately or after overnight storage at 4 degrees C. Thirty-four patients were randomized to overnight storage and 34 to immediate processing of PBPC; 15 were excluded from analysis due to tumor progression or inadequate CD34+ cell mobilization. PBPC from 23 patients were stored overnight, while 30 subjects underwent immediate CD34+ selection and cryopreservation. Median yield of CD34+ enrichment was 43.6% in the immediate processing group compared to 39.1% in the overnight storage group (P = 0.339). Neutrophil recovery >500 x 10(9)/l occurred a median of 11 days (range 9-16 days) in the overnight storage group compared to 10.5 days (range 9-21 days) in the immediate processing group (P = 0.421). Median day to platelet transfusion independence was 13 (range 7-43) days in the overnight storage group vs 13.5 (range 8-35) days in those assigned to immediate processing (P = 0.933). We conclude that storage of PBPC overnight at 4 degrees C allows pooling of consecutive-day collections resulting in decreased costs and processing time without compromising neutrophil and platelet engraftment after infusion of CD34+-selected progenitor cells. Bone Marrow Transplantation(2000) 25, 559-566.     

Ifosfamide in combination with paclitaxel or doxorubicin: regimens which effectively mobilize peripheral blood progenitor cells while demonstrating anti-tumor activity in patients with metastatic breast cancer

For patients with metastatic breast cancer (MBC) who undergo high-dose therapy with autologous peripheral blood progenitor cell (PBPC) transplantation, an important prerequisite is a mobilization regimen that efficiently mobilizes PBPCs while producing an effective anti-tumor effect. We prospectively evaluated ifosfamide-based chemotherapy for mobilization efficiency, toxicity and disease response in 37 patients. Patients received two cycles of the ifosfamide-based regimen; ifosfamide (5 g/m2 with conventional-dose cycle and 6 g/m2 with mobilization cycle) with either 50 mg/m2 doxorubicin (if limited prior anthracycline and/or progression more than 12 months after an anthracycline-based regimen) or 175 mg/m2 paclitaxel. For the mobilization cycle, all patients received additional G-CSF (10 microg/kg SC, daily) commencing 24 h after completion of chemotherapy. The target yield was >6x10(6) CD34+ cells/kg, sufficient to support the subsequent three cycles of high-dose therapy. The mobilization therapy was well tolerated and the peak days for peripheral blood (PB) CD34+ cells were days 10-13 with no significant differences in the PB CD34+ cells mobilization kinetics between the ifosfamide-doxorubicin vs. ifosfamide-paclitaxel regimens. The median PBPC CD34+ cell content ranged from 2.9 to 4.0x10(6)/kg per day during days 9-14. After a median of 3 (range 1-5) collection days, the median total CD34+ cell, CFU-GM and MNC for all 44 individual sets of collections was 9.2x10(6)/kg (range 0.16-54.9), 37x10(4)/kg (range 5.7-247) and 7.3x10(8)/kg (range 2.1-26.1), respectively. The PBPC target yield was achieved in 35 of the 37 patients. The overall response rate for the 31 evaluable patients was 68% with 10% having progressive disease. Thirty-three patients have subsequently received high-dose therapy consisting of three planned cycles of high-dose ifosfamide, thiotepa and paclitaxel with each cycle supported with PBPCs. Rapid neutrophil and platelet recovery has been observed. Ifosfamide with G-CSF in combination with doxorubicin or paclitaxel achieves effective mobilization of PBPC and anti-tumor activity with minimal toxicity.