Day Of Apheresis Research Articles

Influence Of Race and Ethnicity On The Collection Of G-CSF Mobilized Peripheral Blood Stem Cells From Unrelated Donors, a Center For International Blood and Marrow Transplant Research Analysis

▪Peripheral blood stem cell (PBSC) collection is increasingly used in allogeneic stem cell transplantation. However, a small percentage of healthy donors have a poor mobilization response to G-CSF. Very little information exists on the effect of donor race or ethnicity on PBSC mobilization. We analyzed 10776 unrelated donors from the National Marrow Donor Program (NMDP) who underwent G-CSF mobilized PBSC collection from 2006–2012. We investigated the effect of self-reported donor race/ethnicity on collection efficiency, defined as number of CD34+ cells/L (of donor blood processed), number of mononuclear cells (MNC)/L and CD34+ cells/MNC collected on the first day of apheresis. Categorical variables were analyzed by the Chi-square test and the Kruskal-Wallis test was used for continuous variables. A linear regression model was used to compare the various race/ethnic groups while controlling for potential confounding factors (such as age, BMI, gender, and year of apheresis). The result of our analysis is shown in Table 1. Univariate analysis revealed statistically significant differences in CD34+ cells/L, MNC/L and CD34+/MNC in all races analyzed. In general, African Americans (AA) had the highest collection efficiency while Caucasians had the lowest. Other races/ethnicities had collection efficiencies between the two groups. On multivariate analysis, statistically significant differences in CD34+ cell/L were seen in Hispanics, AA and Asian/Pacific Islanders (API), primarily in the obese (Hispanic, AA, API) and overweight (AA, API) donors. In the API group the differences in collection efficiency were predominately seen in males. No differences were seen between Caucasians and Native Americans. This study reveals significant racial/ethnic differences in the efficiency of collection of CD34+ cells in unrelated donors. Although these differences do not appear to interfere with the ability to collect adequate numbers of PBSC, it is currently unknown why they exist. This is an area for continued research. Disclosures:No relevant conflicts of interest to declare.

Over a Third Of Donors Who Are Smaller Than Their Recipient Fail To Meet The CD34+ Cell Dose Requested For PBSC Transplantation

Background It is of clinical relevance to recognize donors who are unlikely to meet the requested stem cell dose for transplantation, as this group may benefit from an alternative mobilization regimen. This study was performed to evaluate the frequency of unrelated donor peripheral blood stem cells (PBSC) collections that met the requested dose and the impact of donor factors on this. Methods All sequential PBSC collections facilitated by the national registry (n = 325) from January through December 2011 were analyzed. All donors were mobilized with lenograstim at 10 μg/kg/day subcutaneously ± 10%. G-CSF was administered for four consecutive days. If the CD34 target cell yield was not achieved after one day of apheresis, a further dose of G-CSF was given and a second collection performed (to a maximum of two aphereses). Apheresis was carried out in 1 of 4 collection centers using the COBE Spectra device. The standard collection time was 4 hours. Donor factors analyzed included age, gender, weight and presence of a central line. Results Donor characteristics are shown in table 1. The median cell dose requested was 4 x 106 CD34+cells/kg recipient weight (range 3-10). The median CD34 dose collected was 6.0 x 106/kg (range 0.44-156.7). 71% of requests were met after 1 day and 85% of requests were met after 2 days of collection. In univariate analysis, we found that donor weight (t-test, p< 0.001) and female gender (OR= 5.5; 95% CI 3, 9.8; chi square, p< 0.001) were significantly associated with not reaching the target yield. Any negative difference in weight between donor and recipient resulted in a higher chance of not meeting the requested dose (chi square, p< 0.005). Even a negative weight difference of 5 kg resulted in an odds ratio of not meeting the requested dose of 2.5 (95% CI 1.5, 4.1) after 1 day of collection and an odds ratio of 2 (95% CI 1.1, 3.8) after 2 days of collection. Age and having a central line in situ were not significantly associated with reaching the requested cell dose. All the above findings were valid both after 1 day and 2 days of collection. After stepwise binary logistic regression, gender (p < 0.001) and difference between donor and recipient weight (p = 0.001) remained significantly associated with target dose being met after 1 day of collection. There was a trend towards significance after 2 days of collection (p = 0.09). Interestingly, donor weight lost significance after adjusting for gender (p = 0.21). Poor mobilizers were defined as a mobilization of less than 2 x 106 CD34 cells per recipient weight. Female gender (OR = 5.7; 95% CI 2.1, 12.2; chi square, p < 0.001), donor weight (t-test, p< 0.001) and difference between donor and recipient weight (t-test, p < 0.001) were associated with poor mobilization. A donor that was more than 5 kg lighter than its recipient was significantly more at risk of being a poor mobilizer (OR: 5.7; 95% CI 2.2, 15; chi square, p < 0.001). Only the difference between donor and recipient weight remained significant after multivariate analysis (p < 0.05). Conclusions This study shows than women and donors who are lighter than their recipient have a decreased likelihood of meeting the transplant physician's requested dose. Donors who are more than 5 kg lighter than their recipient are especially at risk. New strategies to improve mobilization in such donors are needed. Previous studies have shown that G-CSF administered every 12h at doses of 5 or 6 μg/kg provides better yields than 10 μg/kg once daily, without an increase in morbidity. A randomized trial comparing twice daily administration of G-CSF with the standard dose in groups at risk may be valuable. Studies investigating the use of novel agents (such as Plerixafor) could also be considered in donors at risk of poor mobilization. Disclosures: No relevant conflicts of interest to declare.

The Use Of Plerixafor In Hard-To-Mobilize Lymphoma and Multiple Myeloma Patients Not Only Provide Sufficient Numbers Of Pbpcs To Proceed To High Dose Therapy, But Also Have a Positive Impact On Survival

High dose therapy followed by autologous stem cell support (HDT) is a curative treatment in selected lymphoma patients. Moreover, HDT has been shown to significantly increase progression-free survival in multiple myeloma (MM) patients. To obtain a quick and sustained engraftment after high dose therapy, a minimal number of 2x106 CD34+ cells/kg are desirable. However, in 15-20% of the lymphoma and MM patients insufficient numbers of CD34+ cells are harvested. These patients, characterized as poor mobilizers, will either be considered for remobilization, or can not be offered high dose therapy. Furthermore, previous findings have shown that poorly mobilizing lymphoma patients given HDT have a less favorable prognosis than good mobilizers. Recently, new mobilizing agents including plerixafor, a CXCR4 antagonist, have been developed. We, like others, have demonstrated that with a low concentration of CD34+ cells (5-10 cells/µL) and a total white cell count >10x109/L, addition of plerixafor resulted in successful stem cell harvesting in these poor mobilizing patients. However, little is known about the clinical outcome following high dose therapy of hard to mobilize patients given plerixafor.In the present study, we have mobilized and harvested 29 poor-mobilizers from January 2010 to December 2012, including 17 lymphoma patients and 12 MM patients. Ten patients were remobilized with G-CSF and plerixafor (8 MM patients and 2 lymphoma patients), whereas 19 patients were given plerixafor upfront in the primary mobilization attempt in addition to chemotherapy and G-CSF. The 17 lymphoma patients were followed up after reinfusion of autologous stem cells with regard to short-term and long-term engraftment as well as relapse and death.The day prior to harvest of the 29 patients, the level of leukocytes was 11.0x109 cells/L (median; range 3.0-40.5), and the CD34+ concentration was 5.5x106/L (median; range 1.9-20.8). Following plerixafor injection, the concentration of CD34+ cells increased to 25.5 x106/L (median; range 5.5-65.6). The patients were then successfully harvested (median: 3.9x106 CD34+cells/kg; range: 1.8-7.2) with 1-2 days of apheresis, although one of the patients only obtained 1.8x106CD34+cells/kg.In the 17 lymphoma patients receiving high dose therapy followed by autologous stem cell support we observed that time to short-term engraftment, defined by neutrophils >0.5x109/L and thrombocytes >20x109/L were 11 days (median; range 8-19) and 14 days (median; range 10-100) respectively. As an estimate of long-term engraftment we also examined the thrombocyte levels at day 100 after reinfusion. The median level was 135x109/L (range 27-398). Moreover, in contrast to previous findings we have observed durable responses with event free survival of 77% and overall survival of 93% (Median observation time: 24 months). In the MM patients the overall survival observed is 66%.In conclusion, our findings show that addition of plerixafor is successful in mobilization of hematopoietic stem cells in poorly mobilizing patients resulting in a fast and sustained engraftment as well as equal prognosis for both good mobilizing lymphoma and MM patients after high dose therapy with autologous stem cell support. Our clinical findings therefore justify the extra costs of plerixafor in hard-to-mobilize patients. Disclosures:Josefsen:Genzyme: Travel fund 2011 Other.

Mobilization Scheme With Cytarabine In Poor Mobilizers Patients Diagnosed With Lymphoma

IntroductionMobilization regimens for hematopoietic stem cell transplantation have not undergone major changes except for the introduction of new drugs such as plerixafor. However, in patients receiving multiple lines of treatment, to obtain a suitable amount of hematopoietic progenitors (PH) is often difficult even with the addition of new drugs. We present our experience with a protocol of mobilization for poor mobilizer patients based on the use of cytarabine. Material and MethodsFrom a total of 111 patients diagnosed with lymphoma who underwent autologous hematopoietic progenitors in our center from January 2005 to March 2013, 32 patients (35% of total) with previous mobilization failure, received cytarabine 400 mg/m2 /day x3 days + G-CSF (filgrastim or lenograstim) 10-16 mg /kg/day from day 7 to the end of collection. Cell blood cound and CD34 assays in peripheral blood were performed from day +11 postchemotherapy, and apheresis was started when CD34 > 10 x10e6/L. Results30 patients had non-Hodgkin lymphoma (NHL) (13 diffuse large B-cell lymphoma, 7 mantle cell lymphoma, 5 follicular lymphoma, 2 MALT lymphoma, 1 angioimmunoblastic lymphoma, 2 cutaneous lymphomas) and 2 Hodgkin's lymphoma (HL). Median age was 49 years (range 27-67). Median number of treatment lines prior to mobilization was 3 (1-5). In all 30 patients with NHL, an adequate amount of CD34 + cells was obtained. Only one patient with HL, who had previously received 5 lines of chemotherapy, did not mobilize. The average time from the end of chemotherapy to start of apheresis was 13.7 days (12-20). The average number of CD34 + cells circulating the starting day of apheresis was 41/μL (11-109). The mean of apheresis performed was 1.8 (1-3) with an average amount of CD34 obtained of 4.69 x10e6/kg (1.5-6.8). All patients received outpatient treatment and only 2 required hospitalization: one for short-term neutropenic fever and another due to a limited cutaneous hemorrhage during the neutropenia phase. All patients were transplanted without incidence and successfully engrafted. None required G-CSF early postransplant. ConclusionsMobilization with intermediate-dose cytarabine has proven to be a cost-effective regimen in lymphoma patients with prior mobilization failure. Disclosures:No relevant conflicts of interest to declare.

Bendamustine (Treanda®)-Based Regimens Are Effective In Mobilizing Peripheral Blood Hematopoietic Stem Cells For Autologous Transplantation

▪ BackgroundHigh dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard of care for patients with advanced or treatment refractory multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Stem cell proliferation and mobilization can be enhanced though the addition of myelosuppressive chemotherapy prior to GCSF administration. Chemotherapeutic agents without cross resistance to prior therapies may support peripheral blood stem cell (PBSC) collection and improve patient outcomes by exacting a more potent direct anti-tumor effect prior to ASCT. Bendamustine (Treanda®) is a synthetic chemotherapeutic agent that shares structural similarities to both purine analog and alkylating agents without significant cross resistance to other compounds in either drug class. Bendamustine appears to have low stem cell toxicity in vitro, is well tolerated, and has activity in MM and NHL, but the potential for the purine moiety to adversely impact stem cell reserve is unknown. We hypothesized that bendamustine's activity in patients with disease resistant to first line therapies makes it a logical candidate for chemotherapy based PBSC mobilization and tested its impact on stem cell yield. MethodsPatients were eligible if they had relapsed or refractory MM, B-cell NHL or T-cell NHL and were candidates for ASCT. Other criteria included: age >18 years, ANC >1,500/mm3, platelets >100,000/mm3, adequate renal and hepatic function, <3 prior myelotoxic regimens, <6 cycles of lenalidomide, no failed mobilization attempt, and no prior pelvic/spinal irradiation. Patients received 1 cycle of BED therapy [bendamustine (120 mg/m2 IV d 1, 2 - provided along with financial support for this study by Teva Pharmaceuticals), etoposide (200 mg/m2 IV d 1- 3), dexamethasone (40 mg PO d 1- 4), delivered as an outpatient, followed by filgrastim (initially 10 mcg/kg/d sc; starting on d 5 through end of collection)]. Apheresis was initiated when peripheral blood CD34 cell counts were >5/µL. The primary endpoint was successful mobilization, defined as collection of >2.0 x 106CD34 cells/kg. AEs were graded using the CTCAE v4.0. ResultsThirty-seven patients (32 MM, 4B-cell NHL, 1 NK/T-cell NHL) were treated. The median age was 60 years (range 43-70). The median number of prior therapies was 1 (range 1-3) for MM and 2 (range 1-3) for NHL patients. All patients (37/37) were successfully mobilized. The median number of CD34+ cells collected was 19.43 x 106/kg (range 4.35 to 55.51 x 106). All MM patients collected >10 x 106 CD34+cells/kg. The median time from the start of BED mobilization therapy to the first day of CD34 stem cell collection was 12 days (range 9 to 20 days). The median number of apheresis days was 1 (range 1 to 4). A predictable pattern of leucocyte nadir and recovery was demonstrated (95% of patients started apheresis between days 9-13). Two patients (5%) were given plerixafor and for 2 patients (5%) GCSF was increased to 16 mcg/kg twice daily. Among the 37 patients mobilized and collected, 31 have thus far undergone ASCT and 100% (31/31) achieved an unsupported neutrophil count >500/µL at a median of 15 days (range 7-19) after PBSC infusion and a platelet count >20K/µL at a median of 11 days (range 8-14). Ten SAEs were observed in 8 patients and 1 patient died due to disease progression prior to ASCT. SAEs include: neutropenic fever (1, grade [GR] 3), bone pain (2, GR 3), renal insufficiency (1, GR 1), atrial fibrillation (1, GR 2), hypotension (1, GR 3), stroke (1, GR 2), and one patient accounted for 3 SAEs including GR 3 tumor lysis syndrome and sepsis and GR 5 disease progression. Among twenty-nine evaluable patients to date, responses include: CR= 4 PR=2, SD=19 and PD=4. The ORR to this single cycle of therapy was 21%. ConclusionsPBSC mobilization with BED is safe and effective. BED is not an acute stem cell toxin. Large numbers of stem cells were rapidly mobilized and resulted in short durations of apheresis. No patient with MM collected <10 x 106 CD34+ cells/kg (sufficient for 2 ASCTs). Twenty-one percent of patients demonstrated a measurable response to a single cycle of BED therapy and an additional 65% of patients had stable disease. In patients who were transplanted, the time to neutrophil and platelet engraftment was comparable to other chemotherapy based mobilization regimens. The BED regimen was well tolerated and these findings suggest that the role of BED in PBSC mobilization should be further explored. Disclosures:No relevant conflicts of interest to declare.

Use Of Biosimilar G-CSF Compared With Lenograstim In Autologous Haematopoietic Stem Cell Transplant and In Sibling Allogeneic Transplant

IntroductionBiosimilar filgrastim is now widely used for haematopoietic stem cell mobilisation in Europe. Previous studies have reported differences in mobilisation efficacy between originator filgrastim and lenograstim, although others have reported comparable efficacy. This is the first study to compare biosimilar filgrastim with lenograstim for autologous haematopoietic stem cell transplant (HSCT). We also report our use of biosimilar filgrastim for mobilisation in sibling allogeneic transplant, for which there is limited previous data. MethodsData from patients with lymphoma or multiple myeloma (MM) who underwent autologous HSCT mobilised with biosimilar filgrastim (HX575) between October 2011 and April 2013 at St Bartholomew's Hospital, London, were compared with a historical control group of patients who underwent HCST using a similar mobilisation protocol with lenograstim from January 2009 to September 2011. Peripheral blood (PB) cells counts (white blood cell [WBC] and CD34+ cells) were monitored after 7–8 consecutive days of G-CSF injection (approximately 5 μg/kg) and apheresis was performed on day 8 if PB CD34+ cell count was ≥10 cells/µl. G-CSF administration and apheresis were then performed daily until a PB CD34+ cell dose of ≥2.0 x106/kg (lymphoma), ≥ 4.0 x106/kg (MM ≥60 years old) or ≥ 8.0 x106/kg (MM <60 years old) was achieved. Data from a separate group of sibling donors and recipients with haematological malignancies who underwent allogeneic HSCT between October 2010 and April 2013 are also reported. ResultsA total of 259 patients were included in the autologous HSCT comparison (biosimilar filgrastim, n=104; lenograstim, n=155). Both groups had similar characteristics (overall, 66% male, median age 56 years) although the biosimilar group had a lower percentage of patients with lymphoma (19% vs 35%). In patients with lymphoma and older MM patients (≥60 years old), no significant differences were observed between groups with regard to stem cell mobilisation parameters. However, in MM patients <60 years old, all parameters were significantly superior in the biosimilar filgrastim group compared with lenograstim, including the need for one rather the two aphereses (Table 1).Among patients who proceeded to transplant, no significant differences were observed between biosimilar filgrastim and lenograstim in median number of days to ANC recovery > 0.5 x109/l (lymphoma: 13 [9, 35] vs 13 days [9, 36]; MM: 14 [9, 34] vs 12 [10, 33] days) or platelet recovery > 20 x109/l (lymphoma: 21 [9, 35] vs 23 days [10, 35]; MM: 19 [9, 38] vs 18 [9, 39] days). In the allogeneic setting, 48 sibling donors received biosimilar filgrastim. Mean CD34+ count at the first apheresis was 6.1 x 106/kg. Thirteen donors needed a second apheresis, four of whom required a third. Among the recipients, median days to ANC recovery was 16 (10–28) and to platelet recovery was 13 (9–54). ConclusionsBiosimilar filgrastim is as effective as lenograstim for autologous HSCT in patients with lymphoma or MM patients ≥60 years old. However, mobilisation with biosimilar filgrastim appeared to be superior to that with lenograstim in younger MM patients. Biosimilar filgrastim was also successfully used to mobilise sibling donors for allogeneic transplantation. Disclosures:Agrawal:Sandoz Biopharmaceuticals: Consultancy, Honoraria, Research Funding.

Phase 2 trial of intravenously administered plerixafor for stem cell mobilization in patients with multiple myeloma following lenalidomide-based initial therapy

Initial therapy of multiple myeloma with lenalidomide-based regimens can compromise stem cell collection, which can be overcome with the addition of plerixafor. Plerixafor is typically given subcutaneously (SQ), with collection approximately 11 hours later for maximum yield. Intravenous (IV) administration may allow more rapid and predictable mobilization. This trial was designed to assess the efficacy and feasibility of IV plerixafor in patients receiving initial therapy with a lenalidomide-based regimen. Patients received G-CSF at 10 μg/kg/day for 4 days followed by IV plerixafor at 0.24 mg/kg/dose starting on day 5; plerixafor administered early in the morning with apheresis 4–5 hours later. Thirty-eight (97%) patients collected at least 3×106 CD34+ cells/kg within 2 days of apheresis. The median CD34+ cells/kg after 1 day of collection was 3.9×106 (range; 0.7–9.2) and after two days of collection was 6.99×106 (range: 1.1–16.5). There were no grade 3 or 4 non-hematological adverse events and one patient experienced grade 4 thrombocytopenia. The most common adverse events were nausea, diarrhea and abdominal bloating. IV plerixafor is an effective strategy for mobilization with low failure rate and is well tolerated. It offers flexibility with a schedule of early morning infusion followed by apheresis later in the day.

Peripheral blood stem cell yield calculated using preapheresis absolute CD34+ cell count, peripheral blood volume processed, and donor body weight accurately predicts actual yield at multiple centers.

Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula. Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected. Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (>2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (>5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions. The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.

Experience with Plerixafor for Hematopoietic Cell Mobilization in Nine Patients with Germ Cell Tumors

To evaluate the efficacy of plerixafor as a just-in-time therapy for patients with germ cell tumors who were identified as poor hematopoietic cell mobilizers after the initiation of apheresis. Case series. National Cancer Institute-designated cancer center. Nine patients with germ cell tumors who received plerixafor as an adjunct to granulocyte colony-stimulating factor (G-CSF) for hematopoietic cell mobilization in an attempt to prevent mobilization failure between January 2009 and December 2012. Patients were heavily pretreated, having received at least four prior treatment cycles. A median of three total apheresis days (range 1-4 days) was required for all patients, but a median of two apheresis days (range 1-2 days) was needed after the initiation of plerixafor. A median of 0.9 × 10⁶ CD34⁺ cells/kg (range 0.3-1.5 × 10⁶ CD34⁺ cells/kg) was harvested with G-CSF mobilization alone; in addition, a median of 2.6 × 10⁶ CD34⁺ cells/kg (range 0.6-32 × 10⁶ CD34⁺ cells/kg) was harvested using plerixafor. All nine patients received high-dose carboplatin and etoposide followed by hematopoietic cell transplantation. The median time to neutrophil engraftment was 11 days (range 8-12 days). The median time to platelet engraftment was 16 days (range 10-22 days). The use of plerixafor in addition to G-CSF as just-in-time therapy permits patients with germ cell tumors to pursue potentially curative therapy with high-dose chemotherapy followed by autologous stem cell rescue.

Comparison of the efficacy of peripheral blood stem cell mobilization using G-CSF alone from healthy donors and patients with hematologic malignancies

Peripheral blood stem cell (PBSC) collection using granulocyte colony-stimulating factor (G-CSF) alone is superior to the combination of chemotherapy and G-CSF in terms of low morbidity, short duration of mobilization and low cost. We retrospectively compared the results of PBSC collection using G-CSF alone in 11 patients with malignant lymphoma (ML), 23 patients with plasma cell neoplasms (PCN) and 48 healthy donors. The geometric mean number of CD34+ cells/kg obtained on the first day of collection was 0.99×106/kg in ML patients, 2.26×106/kg in PCN patients, and 3.36×106/kg in healthy donors. The probability of collecting at least 1×106/kg CD34+ cells/kg during a single course of apheresis was 90.9% in ML patients, 95.7% in PCN patients, and 100% in healthy donors. In a multiple regression analysis of the CD34+ cell yields on the first day of apheresis, we identified disease, the baseline white blood cell count (WBC), platelet count, and lactate dehydrogenase as independent significant variables. Particularly, disease was strongly associated with the CD34+ cell yield, probably due to the difference in the number of previous chemotherapy cycles. In conclusion, the minimal dose of CD34+ cells for autologous transplantation was collected in almost all patients with hematological malignancies. However, patients who have received repeated cycles of chemotherapy, such as patients with ML, and those who have low WBC counts and/or platelet counts may be at higher risk for poor mobilization.

Hematopoietic progenitor cell mobilization using low‐dose cyclophosphamide and granulocyte colony‐stimulating factor for multiple myeloma

High-dose chemotherapy (HDT) supported by autologous stem cell transplantation (ASCT) has long been one of the standards of care for younger patients with multiple myeloma (MM). Cyclophosphamide (CY) plus granulocyte colony-stimulating factor (G-CSF) has been the conventional preparation for hematopoietic progenitor cell (HPC) mobilization, although the optimal dosage of CY in this setting has not yet been clearly defined. This study investigated the efficacy and safety of low-dose (LD-)CY (1.5 g/m(2)) plus G-CSF for conditioning for HPC apheresis harvest (HPC-A) in 18 MM patients, and compared it with a regimen consisting of intermediate-dose (ID)-CY (4 g/m(2)) plus G-CSF for 13 MM patients. Eleven patients in the former and six in the latter were treated with bortezomib (BTZ) during the induction therapy. Both regimens were comparably effective in terms of CD34(+) cell yields, while adverse events, such as leukopenia, thrombocytopenia, and febrile neutropenia, occurred significantly less frequently in the LD-CY cohort. All patients in LD-CY cohort started and completed their apheresis on day 7 or 8, whereas for the ID-CY cohort the day of first apheresis varied widely from day 8 to 15. These findings indicate that the LD-CY regimen is as effective as ID-CY for HPC mobilization, while the former is clearly more practicable and convenient than the ID-CY regimen for patients with MM.

Outcomes and costs of autologous stem cell mobilization with chemotherapy plus G-CSF vs G-CSF alone

Chemotherapy plus granulocyte colony stimulating factor (G-CSF) (C+G) and G-CSF alone are two of the most common methods of mobilizing CD34+ cells for autologous hematopoietic stem cell transplantation (AHSCT). In order to compare and determine real-world outcomes and costs of these strategies, we performed a retrospective study of 226 consecutive patients at 11 medical centers (64 lymphoma, 162 multiple myeloma), of whom 55% and 66% received C+G. Patients with C+G collected more CD34+ cells/day than G-CSF alone (lymphoma: average 5.51x106 cells/kg on day 1 vs. 2.92x106 cells/kg, p=0.0231; myeloma: 4.16x106 cells/kg vs. 3.69x106 cells/kg, p<0.00001) and required fewer days of apheresis (lymphoma: average 2.11 days vs. 2.96, p=0.012; myeloma: 2.02 vs. 2.83 days, p=0.0015), though nearly all patients ultimately reached the goal of 2x106 cells/kg. With the exception of higher rates of febrile neutropenia in myeloma patients with C+G (17% vs. 2%, p<0.05), toxicities and other outcomes were similar. Mobilization with C+G cost significantly more (lymphoma: median $10,300 vs. $7,300, p<0.0001; myeloma: $8,800 vs. $5,600, p<0.0001), though re-mobilization adds $6,700 for drugs alone. Our results suggest that while both C+G and G-CSF alone are effective mobilization strategies, C+G may be more cost-effective for patients at high risk of insufficient mobilization.

Circulating endothelial cell kinetics and their potential predictive value during mobilization procedure

Circulating endothelial cells (CECs) in patients with hematological malignancies are assessed as a noninvasive marker of angiogenesis. The aim of this study was to evaluate the numbers of CECs and their subsets during mobilization of hematopoietic stem cells. Thirty-eight patients were enrolled to the study (19 females and 19 males) at median age of 56.5 years. The group consisted of patients with multiple myeloma (26), lymphoma (10), and acute myeloid leukemia (2). Blood samples were collected before chemotherapy (0), 1 day after chemotherapy (Cht+1), on the day G-CSF commenced (G0), after 1 day of G-CSF (G+1), and on the day of the first apheresis. CECs were evaluated by four-color flow cytometry. Circulating progenitor cells were defined as CD45-/CD34+/CD31+/CD133+. Apoptotic CECs (ApoCECs) were defined as CD146+/AnnexinV+. Median (Me) CECs number was 10.5/µl and it decreased after chemotherapy (Me = 8.3/µl, P < 0.001 when compared with baseline). Based on the number of aphereses needed to obtain 2 × 10(6)/kg CD34+ cells, patients were divided into "highly efficient" (one apheresis) and "poorly efficient" mobilizers (two or more aphereses). Median ApoCEC at Day G+1 was lower in highly efficient than in poorly efficient mobilizers (Me = 3.1/µl vs. Me = 5.1/µl, P = 0.02). ApoCEC at Day G+1 correlated with the number of aphereses (r = 0.48, P = 0.03). In multivariate analysis, ApoCEC at Day G+1 was an independent factor for successful mobilization during one apheresis. CECs and their subsets change significantly during mobilization of HSCs. ApoCECs measured at the time of G-CSF commencement can predict the efficacy of HSC collection.

Which regimen is better for stem cell mobilization of lymphoma patients?

Although chemotherapy combined with G-CSF is an effective method for hematopoietic stem cell mobilization, standard chemotherapy protocol leading to best stem cell yield is not defined. In our study, we aimed to assess the impact of chemotherapy choice on mobilization outcome in lymphoma patients. Patients were mobilized with cyclophosphamide (n:15), ASHAP (n:11) or VGEPP (n:12) protocols. Groups were similar according to collected CD34+ cell count, total nucleated cell count and median apheresis days. Five out of fifteen (33%) patients could not be mobilized in Cy group but there was only one failed mobilization attempt in both salvage groups (9% with ASHAP vs 8% with VGEPP). In conclusion, we showed that VGEPP and ASHAP are safe protocols in terms of stem cell mobilization and have similar mobilization capacity as cyclophosphamide alone.

Lenograstim compared to filgrastim for the mobilization of hematopoietic stem cells in healthy donors

Recombinant human granulocyte-colony-stimulating factor (G-CSF) is used to mobilize hematopoietic stem cells for both autologous and allogeneic hematopoietic stem cell transplantation. The recombinant products clinically available are lenograstim and filgrastim, which differ from a biologic point of view as well as from their economical impact. In this regard, some studies have shown different in vitro activities although clinical studies comparing both drugs in the allogeneic transplant setting are scanty. In the current study we compare the efficacy of lenograstim and filgrastim in terms of number of circulating CD34+ cells/μL during the fifth day of G-CSF administration, the number of days of apheresis required to obtain the target cell dose, the median of CD34+ cells collected on the first day of apheresis, or the median number of total CD34+ cells collected at the end of the procedure, in a series of 146 healthy donors undergoing hematopoietic stem cell mobilization for allogeneic transplantation. We observed that, using a comparable dose for the two products, no significant differences were observed between the two groups. In conclusion, the current retrospective study shows that lenograstim and filgrastim are similar in terms of efficacy for the mobilization of hematopoietic stem cells in healthy donors.

Efficacy of stem cell mobilization in patients with newly diagnosed multiple myeloma after a CTD (cyclophosphamide, thalidomide, and dexamethasone) regimen

The CTD (cyclophosphamide, thalidomide, and dexamethasone) regimen is known to be an effective primary therapy in patients with newly diagnosed multiple myeloma (MM). However, stem cell yields after CTD remain inconsistent. The aim of the present study is to identify the influence of the CTD regimen on the outcome of peripheral blood stem cell (PBSC) collection. Fifty-four patients received four cycles of CTD, and PBSCs were mobilized with cyclophosphamide and G-CSF or with G-CSF alone. Each patient from whom ≤4.0×10(6) CD34(+) cells/kg were collected received a second mobilization course. The median duration from the start of a CTD regimen to the first collection was 4.3months. Forty-eight patients were mobilized with cyclophosphamide followed by G-CSF, and six patients were mobilized with G-CSF alone. The median day of apheresis was day 3 (range day 2-day 5). The overall response rate at mobilization was 96.3%, including 11.1% complete response, 22.2% very good partial response, and 63.0% partial response. The median number of harvested CD34(+) cells was 12.8×10(6) cells/kg. At the second mobilization, 88.9% of patients reached the minimal stem cell collection target of ≥2.0×10(6) cells/kg, and 75.9% of patients achieved the collection target of ≥4.0×10(6) cells/kg. CTD within four cycles is an effective primary therapy in patients with newly diagnosed MM and only minimally affects subsequent PBSC collection.

High Dose Sargramostim (GM-CSF) Combined with IV Plerixafor for the Mobilization of Peripheral Blood Stem Cells (PBSC) From Normal HLA-Matched Allogeneic Sibling Donors Results in Hypercoagulability

AbstractAbstract ▪4095▪This icon denotes a clinically relevant abstractWe report an interim safety analysis of a phase II trial evaluating GM-CSF and plerixafor for the mobilization of peripheral blood stem cells in normal HLA-matched allogeneic sibling donors, performed due to unexpected toxicity observed with this combination.We have previously reported a lower than expected incidence of acute GVHD in recipients of sibling donor allogeneic HSC transplants mobilized with GM-CSF alone (Devine et al. Blood), as well as similar results using a mouse model of GVHD, in which increased Tregs as well as putative myeloid derived suppressor cells (MDSCs) were observed. However, the use of GM-CSF as a single agent for stem cell mobilization has been limited by an unacceptably high (∼30%) incidence of failure to mobilize and collect adequate stem cell numbers in a single 20 L apheresis procedure. Based upon observed synergy between GM-CSF and plerixafor for HSC mobilization in mice, we hypothesized that this combination in humans might overcome the low stem cell yields observed with either agent alone and result in a PBSC product enriched in Tregs and MDSCs that could reduce GvHD after transplant.A phase II trial was designed, which is ongoing, to evaluate the efficacy of GM-CSF, initially at a dose of 10 mcg/kg SC daily × 5 – 6 days, and plerixafor 320 mcg/kg IV daily starting on day 5, with the primary objective of reduction in the day 1 mobilization failure rate from 33% to <10%, and a planned enrollment of 17 patients. To date 14 donors have been mobilized and 13 recipients transplanted. Initial mobilization with GM-CSF 10mcg/kg was complicated by a high incidence (4/4 donors) of unexpected catheter and IV tubing-associated thrombosis at the time of apheresis, requiring line revision, and in some cases placement of central venous access. The trial was halted for an interim safety analysis, resulting in reduction in the dose of GM-CSF to 5 mcg/kg SC daily × 5–6 days. Since this dose reduction, no significant problems with thrombosis precluding a full 20 L apheresis have been observed among 13 subsequent donors. No evidence of systemic thrombosis has been observed in any donors with this combination. The most common adverse effects have included first dose reaction of severe acute onset bone pain (only in 10mcg/kg dose of GM-CSF), diarrhea, nausea, fatigue, bone pain, injection site reaction, and cardiovascular disorders including bradycardia and transient hypotension. There have been no grade 3–4 adverse events related to mobilization.A preliminary analysis of mobilization in 10 donors with a 20 L minimum apheresis volume demonstrated a failure to collect ≥2×106 CD34/kg recipient weight in 1/10 donors. The mean CD34/Kg recipient weight collected from these donors was 5.25 × 106 CD34/Kg. Among donors who failed to undergo a minimum 20 L apheresis collection, only 2/4 required a second day of aphereis to achieve a collection goal of 2 × 106 CD34/kg, and no donor failed to reach this goal after two days of apheresis. CD34 cell mobilization peaked at 4–9 hours after plerixafor infusion with mean CD34/uL = 38 at 6 hours (SD = 10.35).No recipients had primary graft failure. The median time to neutrophil engraftment was 13 days (range 11 – 15), and median time to platelet engraftment was 24 days (range 19 – 28). All evaluable recipients had 100% peripheral blood donor chimerism at day 30 post transplant. One recipient developed secondary graft failure at day +51, and required reinfusion of G-CSF-mobilized stem cells from his initial donor.The incidence of grades II–IV and III-IV acute GvHD, respectively, among recipients of a GM+P mobilized product was 45% and 18%. The incidence of cGvHD was not evaluable due to the short duration of follow-up. CMV viremia incidence was 38%.Peripheral blood from donors was collected for correlative studies including phenotyping and functional studies, but has not yet been analysed. Further studies evaluating the hypercoagulability associated with higher doses of GM-CSF are ongoing.GM-CSF combined with IV plerixafor is a feasible combination. Higher doses of GM-CSF (10mcg/kg) are associated with first dose reactions, hypercoaguability and catheter thrombosis. Disclosures:Schroeder:Sanofi Oncology/Genzyme: Research Funding. DiPersio:genzyme: Honoraria.

Bendamustine (Treanda®), Etoposide and Dexamethasone (BED) Followed by GCSF Effectively Mobilizes Autologous Peripheral Blood Hematopoietic Stem Cells

AbstractAbstract ▪4126▪This icon denotes a clinically relevant abstract Background:High dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard of care for patients with advanced or treatment refractory multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Stem cell proliferation and mobilization can be enhanced though the addition of myelosuppressive chemotherapy to GCSF administration. Chemotherapeutic agents without cross resistance to prior therapies may support peripheral blood stem cell (PBSC) collection and improve patient outcomes by exacting a more potent direct anti-tumor effect prior to ASCT. Bendamustine (Treanda®) is a synthetic chemotherapeutic agent that shares structural similarities to both purine analog and alkylating agents without significant cross resistance to other compounds in either drug class. Bendamustine appears to have low stem cell toxicity in vitro, is well tolerated, and has activity in MM and NHL. We hypothesized that bendamustine’s activity in patients with disease resistant to first line therapies makes it a logical candidate for chemotherapy based PBSC mobilization. Methods:Patients were eligible if they had relapsed or refractory MM, B-cell NHL or T-cell NHL and were candidates for ASCT. Other criteria included: age >18 years, ANC >1,500/mm3, platelets >100,000/mm3, adequate renal and hepatic function, <3 prior myelotoxic regimens, <6 cycles of lenalidomide, no prior failed mobilization attempt, and no prior pelvic/spinal irradiation. Patients received 1 cycle of BED therapy [bendamustine (120 mg/m2 IV d 1, 2 - provided along with financial support for this study by Teva Pharmaceuticals), etoposide (200 mg/m2 IV d 1– 3), dexamethasone (40 mg PO d 1– 4), delivered as an outpatient, followed by filgrastim (10 mcg/kg/day; starting on d 5 through end of collection)]. Apheresis was initiated when peripheral blood CD34 cell counts were >5/μL. The primary endpoint was successful mobilization, defined as collection of >2.0 × 106CD34 cells/kg. Adverse events (AEs) were graded using the CTCAE v4.0. Results:Twenty patients (16 MM, 3 B-cell NHL, 1 NK/T-cell NHL) were treated. The median age was 59 years (range 43–70), and the median number of prior therapies was 1 (range 1–3) for MM and 2 (range 2–3) for NHL patients. All patients (20/20) were successfully mobilized. The median number of CD34+ cells collected was 19.11 × 106/kg (Mean 22.49; range 4.35 to 55.51 × 106). All MM patients collected >10 × 106 CD34+cells/kg. The median time from BED mobilization therapy to the first day of CD34 stem cell collection was 12 days (mean 12.05; range 10 to 20 days). The median number of days of apheresis was 1 (mean 1.45; range 1 to 4). A predictable pattern of leucocyte nadir and recovery was demonstrated (88% of patients started apheresis between days 10–12). One patient (5%) was given plerixafor and for 2 patients (10%) the dose of GCSF was increased to 16 mcg/kg twice daily. Among the 20 patients mobilized and collected, 12 have thus far undergone ASCT and 100% (12/12) have achieved an unsupported neutrophil count >500/μL at an average of 14.3 days after PBSC infusion and a platelet count >20K/μL at an average of 10 days. Serious AEs (SAEs) were observed in 5 patients and 1 patient died due to disease progression. No unexpected grade 3 or greater treatment related SAEs were seen. Disease response assessments are ongoing. The original protocol design involved 3 agents (bendamustine, dexamethasone and GCSF [BDG]). After the first 3 patients enrolled, the mobilization regimen was modified to include etoposide because BDG did not yield a predictable pattern of leucocyte nadir and recovery, thus complicating timing for apheresis (median time to collection 22 days). The first 3 patients were censored from the analysis, however all 3 patients were successfully mobilized and collected. Conclusions:The initial experience with PBSC mobilization after BED in this phase II study suggests the regimen is safe and effective, while the use of BDG does not yield predictable CD34 kinetics. Time to neutrophil and platelet engraftment after ASCT appears unimpaired when compared with other chemotherapy based mobilization regimens. Large numbers of stem cells were rapidly mobilized and resulted in short durations of apheresis. No patient with MM collected <10 × 106 CD34+ cells/kg (sufficient for 2 ASCTs). The regimen was very well tolerated and these findings suggest that the role of bendamustine in PBSC mobilization should be further explored. Disclosures:Green:Teva Pharmaceuticals: Research Funding. Holmberg:Millenium: Research Funding; Otsuka: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Sanofi: Research Funding. Budde:Teva Pharmaceuticals: Research Funding. Gopal:Teva Pharmaceuticals: Research Funding.

O1-044 - High-Dose Etoposide as an Effective Mobilization Agent in NHL Previously Treated with CHOP ± RITUXIMAB

ABSTRACT Background Etoposide is one of the effective mobilizing agents in non-Hodgkin's lymphoma (NHL), but safety and effectiveness of high-dose etoposide followed by G-CSF is not well defined. We conducted a retrospective study to evaluate the efficacy of high-dose etoposide plus G-CSF compared with other mobilizing agents in peripheral blood stem cell (PBSC) mobilization. Methods A total of 46 patients with NHL who were treated only with CHOP ± Rituximab and sequentially underwent PBSC mobilization between 2006 and 2011 were analyzed. Twenty-two patients received etoposide 500 mg/m2 at day 1, 2, 3 (VP16 group). Total 22 of other patients received ICE or DHAP or CHOP ± Rituximab and 2 patients received G-CSF only (others group). All patients administered G-CSF 10 µg/kg/day until apheresis completed. Chemotherapy-related toxic effects and PBSC mobilization results were compared between the groups. Results In the VP16 group, a median total CD34+ cells collected was 15.79 × 106 cells/kg, 77% of all patients having adequate (>2.0 × 106 cells/kg) CD34+ collections after first day of apheresis compared with a median in the others group of 4.1 × 106 cells/kg (P Conclusions High-dose etoposide improves the effectiveness of mobilization with more than three-fold higher stem cell yield compared with other mobilizing agents. Considering no mortalities in patients with neutropenic fever, high-dose etoposide plus G-CSF is a highly effective mobilizing agent with acceptable toxicity in patients with NHL who were previously treated with CHOP ± rituximab.

Poor mobilization status: a lingering legacy for allograft recipients

Poor mobilization of autologous peripheral blood stem cells (HPC-A) in patients requiring high dose chemotherapy represents an ongoing clinical challenge. A key diffi culty in interpreting the literature in this area is that there is no uniform defi nition of poor mobilization. A mobilization “ failure ” at one institution may represent “ suboptimal mobilization ” at another, and thresholds for defi ning a peripheral blood CD34 count as suffi cient to commence collection vary dramatically between institutions. Th e most common reason for a failure to mobilize and collect HPC-A is prior exposure to cytotoxic chemotherapy, in particular protracted courses of alkylators and purine analogs [1 – 3]. More recently lenalidomide exposure has also been implicated in impairment of HPC-A [4]. A recognition and avoidance of these risk factors and the well-timed use of novel mobilization therapies such as plerixafor have seen a lower incidence and greater ability to salvage those patients demonstrating HPC-A mobilization [5,6]. Where repeated attempts at salvage mobilization have been required to obtain a transplantable dose of cells, there are concerns that this subset of hard-to-mobilize patients have an adverse disease-free and overall survival following autologous transplant [7]. Th e mechanism of the suboptimal outcome in patients with a history of poor HPC-A is likely to be complex. Th is group of patients is enriched for patients with refractory disease, who are likely to have residual tumor involvement within the marrow resulting in cell contamination of the graft (the signifi cance of which remains uncertain [8]), and bone marrow microenvironmental damage as a result of multiple lines of prior therapy and multiple mobilization attempts. As a result of these factors and despite the application of granulocyte-colony stimulating factor (G-CSF) and/or plerixafor there is a small group of patients who ultimately cannot achieve an adequate collection for safe autologous transplant. In this edition of Leukemia and Lymphoma , Crocchiolo and co-authors explore whether a history of poor mobilization continues to impart a similar adverse outcome in a cohort of patients with multiple myeloma or lymphoma despite receiving a normal stem cell donation from an allogeneic donor following reduced intensity conditioning [9]. In a retrospective analysis they identifi ed two cohorts of patients who had previously attempted autologous stem cell mobilization but for various reasons proceeded to allogeneic transplant. Compared to the cohort of prior “ good mobilizers, ” defi ned as a CD34 cell count 20 10 9 /L on the fi rst day of apheresis, the group of “ poor mobilizers, ” who failed to achieve this threshold, had an increased non-relapse mortality. Th is diff erence was not due to impaired myeloid engraftment, as post-allogeneic transplant recovery of neutrophils and platelets was similar in the two cohorts. Somewhat paradoxically, assessment of a sub-cohort who, despite being defi ned as poor mobilizers, ultimately succeeded in the collection of 2 10 6 /kg CD34 cells, showed a slower neutrophil engraftment. Th is fi nding may refl ect a group enriched for patients in whom the disease risk resulted in an imperative to move to transplant, which in turn led to more collection days and/or more repeated mobilization attempts, and who were likely to be more heavily pretreated, with a resultant impairment of the bone marrow microenvironment and delayed allogeneic stem cell engraftment. Overall the poor mobilizer cohort had similar rates of relapse and graft-versus-host disease to those of the good mobilizers. Despite this, the non-relapse mortality and overall survival were signifi cantly worse in the poor mobilizer group. Th is fi nding was independent of the patient/donor gender matching or number of prior autografts. No clear pattern emerged in the cause of death in these patients. In the allograft setting, where the engrafting cells are presumably healthy, the putative “ lesion ” in graft dysfunction is likely to be the marrow microenvironment. Whilst platelet and neutrophil engraftment were not clearly impaired in this study, immune reconstitution was not measured. Recovery of lymphocyte subsets, and perhaps just as importantly lymphocyte function, may lag substantially in poor mobilizer patients. Where it has been studied, posttransplant lymphocyte recovery is directly correlated with post-transplant outcome in the autograft and allograft setting [10 – 12]. Impaired lymphocyte recovery in the poor mobilizer group could translate to increased susceptibility