Peripheral Blood Stem Cell Harvest Research Articles

Feasibility and Kinetics of CD34+ Hematopoietic Cells Mobilization By Low-Dose Pegfilgrastim in Lymphoma Patients

▪Introduction: Hematopoietic stem cell rescue with autologous peripheral blood stem cells (PBSC) following high-dose chemotherapy has been used for the treatment of lymphoma and myeloma. Granulocyte colony-stimulating factor (G-CSF) is used for PBSC mobilization but data on PBSC mobilization by pegfilgrastim is limited. Recent studies showed successful PBSC harvest by single dose of pegfilgrastim given at 6mg or 12mg within 4 days after chemotherapy in patients with malignant lymphoma. However, administration of pegfilgrastim early after chemotherapy administration induces overshoot of neutrophils, which may result in rapid plasma clearance of G-CSF due to internalization of the G-CSF/G-CSF receptor complexes via endocytosis in neutrophils. Previous studies demonstrated that day 7 injection of pegfilgrastim in the course of chemotherapy mitigated the neutrophil overshoot compared to day 4 injection of pegfilgrastim. We hypothesized that day 7 administration of lower dose 3.6mg pegfilgrastim could avoid neutrophil overshoot and efficiently mobilize PBSCs. Here we show the kinetics of CD34+ PBSC mobilization after 3.6mg pegfilgrastim given on day 7 in the course of chemotherapy.Patients and Methods: Between February 2016 and May 2017, twenty patients with malignant lymphoma enrolled in this study (14 DLBCL, 2 AITL, 2 ALCL, 1 ATLL, 1 FL). Median age was 54 (range 30-65). Eight patients had clinical stage III-IV. Median number of prior chemotherapy was 0 (range 0-2). All patients received cytotoxic chemotherapy (13 CHOP, 2 DeVIC, 2 ESHAP, 1 DHAP, 1 EPOCH, 1 HD-AraC) on day 1 and 3.6mg of pegfilgrastim was administered subcutaneously on day 7. Peripheral blood CD34+ cell counts were analyzed from day 11 to 14 after chemotherapy by flowcytometric analysis using single platform method based on ISHAGE guideline. The primary objective is to clarify the kinetics of peripheral blood CD34+ cells without harvesting intervention. CD34+ values on each time point is statistically tested using one-sample t-test. To visualize the primary result, bar graph with mean and its confidence interval on each day is represented with the reference line (Figure). The secondary objectives are to search peak point of CD34+ cell counts after each chemotherapy regimen and the feasibility of pegfilgrastim administration on day 7. Successful mobilization was defined as to achieve more than 10×106/L peripheral blood CD34+ cells on any time points between day 11 and 14. All patients were assessed for toxicity according to the National Cancer Institute Common Toxicity Criteria, version 4.0. This study was approved by the institutional review board and conducted in accordance with the Declaration of Helsinki.Results: Successful mobilization was achieved in 19 of the 20 patients (95%). Mean number (SD) of WBC (×109/L) on each day between day 11 and day 14 was 5.4 (3.7), 11.4 (9.1), 14.2 (9.1) and 13.9 (7.4), respectively. Mean number (SD) of CD34+ cells (×106/L) on each day between day 11 and day 14 was 20.3 (22.5), 38.0 (35.7), 40.3 (39.8), and 40.1 (53.5), respectively. The 98.75% confidence interval [CI] of CD34+ cells (×106/L) on each day between day 11 and day 14 was [6.39-34.22], [16.16-60.25], [15.77-64.97] and [7.09-73.16], respectively (Figure). The number of CD34+ cells on day 12 or 13 showed significantly higher than 10×106/L CD34+ cell (P = 0.0022 and 0.0030, respectively) (Figure). We then compared the peak of CD34+ cells in a peripheral blood in each chemotherapy regimens. The peak day of CD34+ cell in patients who received CHOP regimen was day 13 (mean 54.3 ×106/L, range 15.8-151.0×106/L) . However, in 4 of 5 patients who received platinum containing regimen, CD34+ cells failed to reach the peak before day 14 because of prolonged myelosuppression. The number of prior chemotherapy regimen (0 vs 1-2) was not associated with the kinetics of CD34+ cells (p = 0.35). No infectious events including febrile neutropenia were observed. Pain and LDH elevation (Grade 1-2) were the main adverse events related to pegfilgrastim administration. We had not detected any severe adverse events.Conclusion: Our data indicated that 3.6mg pegfilgrastim on day 7 can efficiently mobilize CD34+ cells to peripheral blood without any severe adverse events. [Display omitted] DisclosuresTeshima:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Research Funding; Kyowa-Hakko Kirin: Research Funding; Pfeizer: Research Funding; Chugai: Research Funding; Bristol-Myers Squibb: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

The Impact of Single Dose Plerixaforas an Adjunct to G-CSF Based Peripheral Blood Stem Cell Mobilisation on the Graft Composition and Outcome for T Replete Haploidentical PBSC Transplantation with Post Transplantation Cyclophosphamide: A Pilot Study

▪Introduction : We conducted a prospective study on T cell and NK cell subset composition of the graftand the transplant outcome with single dose of subcutaneous Plerixafor(Px) to GCSF based mobilisation in T-replete Haploidentical Peripheral blood Stem cell transplantation with post-transplantation cyclophosphamide (PTCy) in 25 donors (G+Px group). This was compared with 26 donors who received G-CSF alone for mobilisation (G group).Material and Methods : With the aim to collect 10 x 106/kg CD34 cells in a single apheresis, donors with peripheral CD 34 count less than 50 cells /µl in the peripheral blood on day 4 of mobilization were administered Injection Plerixafor at the dose of 0.12mcg/kg at 12 midnight in addition to routine GCSF. This was followed by PBSC harvest starting 11 hours later at 11 A.M on the next day. The rest were continued G-CSF only as per protocol.Results: CD 34 cell count[G+Px-136(range, 52-351)vs G-139 (range,72-240) cells/µl ] in the peripheral blood on day 5 as well as that in the graft [G+Px- 2.7(range 1.1-6.0) VsG-2.3(range 0.5-5.3) X106 /ml, p=0.05] comparable between the two groups, despite a significantly lower peripheral CD34 cell count on day 4 in the pleraxifor group (G+Px-33(range, 6-47) vs G-81(58-168) cells/µl, p=0.0001). The total nucleated cell count was higher in the G- group[ 3.4(range 1.7-5.0) vs 3.1(range 1.15-4.73) X108/ml, p=0.05 ]. Despite the lower trend of CD4+ T cells[ 2.3(range 0.3-6.8) Vs 2.7(range 0.53-6.8) X107/ml, p=0.09 ]in the G-CSF group, mobilisation of Tregs was similar(7.1% vs 6.9% in G+Px group,p=0.1). There were no differences noted in the absolute number of NK cells [G+Px-5.3(range 0.8-11.6) vs 5.7.(range 1.7-12.9) X106/ml, p=0.9 ], or the CD56+16+/16- subsets. The time to engraftment was similar in both groups. The incidences of acute and chronic GVHD, non-relapse mortality and relapse were also similar.Conclusion: Addition of single dose pleraxifor to G-CSF mobilisation improves CD34 recovery and does not significantly alter the T and NK cell composition of the graft, including Tregs. No adverse impact was noted on engraftment, GVHD, NRM and relapse. Our study demonstrates that pleraxifor can be safely used as an adjunct to G-CSF to boost CD34 mobilisation without impacting conventional or regulatory T cells and NK cells in the graft. The preliminary data suggests no adverse impact on transplant outcomes. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Usefulness of hematopoietic progenitor cell monitoring to predict autologous peripheral blood stem cell harvest timing: A single-center retrospective study

IntroductionIn autologous peripheral blood stem cell harvest (APBSCH), CD34-positive cells have been measured to assess the numbers of hematopoietic stem cells, but measurement requires specialized equipment. Recently, there was a report that peripheral blood hematopoietic progenitor cells (HPCs) are useful indicators of the presence of hematopoietic stem cells. We examined the usefulness of HPC monitoring to predict APBSCH timing. MethodsWe retrospectively analyzed the relationship between HPC and collected CD34-positive cells in 84 consecutive patients who underwent APBSCH. ResultsAccording to the receiver operating characteristics curve for the collection of ≥2 × 106 CD34-positive cells/kg, the HPC cut-off value on the day before collection was 21/μL, while that on the day of collection was 41/μL. No significant factors were found in the univariate analysis except for the HPC count on the day before collection (p < 0.001) and the day of collection (p < 0.001). According to the multivariate analysis, the HPC count on the day before collection (p < 0.001) and the day of collection (p < 0.001) were also factors that strongly influenced the quantity of CD34-positive cells collected. ConclusionOur results suggest that the HPC count on not only the day of collection but also the day before collection is a good indicator for appropriate APBSCH timing.

Treatment Efficacy and Outcomes in HIV-Related Plasmablastic Lymphoma: The Results of Multicenter Retrospective Study in Russia

Background Plasmablastic lymphoma (PbL) is a rare and aggressive B-cell malignancy highly associated with HIV. Despite improved understanding of this disease, its prognosis remains poor with short overall survival. There is no standard of care for this entity. Recent advances in the treatment of HIV-associated and aggressive lymphomas have not yet significantly improved the outcomes of patients with PbL. Methods We investigate epidemiological characteristics and the results of the treatment of the HIV-related PbL in large cohort of HIV-related lymphoma patients for a 7-year period (2014-2020). During the observation period, 22 cases of HIV-related PbL were registered in three centers and selected for the analysis from the national multicenter retrospective study database. The median follow-up was 17,8 (4-57,4) months. Results The PbL accounted for 8,9% of lymphomas in HIV-infected patients (22/247). The median age was 42 years (32-61), males - 9 (41%). Most of the patients (n=19, 86%) had III-IV stages and B-symptoms were present in 8 patients (36%). CNS involvement was diagnosed in 8 patients (36%). The median of ECOG score was I (I-III). Half of patients had viral hepatitis as a co-infection including HCV (n=9), HCV and HBV (n=1), HCV, HBV and HDV (n=1). HIV and lymphoma were diagnosed simultaneously in 7 patients (32%). Median time from HIV infection to the lymphoma onset was 4 years (1,5 month - 17,5 years). The only one patient did not receive cART for an unknown reason. The median number of CD4+ cells at the moment of chemotherapy (CT) started was 151 cell/mcl (13 - 374). Frontline CT were following: CHOP±E - 9 (41%), EPOCH - 11 (50%), hyper-CVAD - 1 (4,5%), dexamethasone - 1 (4,5%). Bortezomib was added to frontline treatment in 3 (13,6%) patients, HDC with auto-HSCT had been done as a first line therapy in 2 (9%) patients. A total of 16 patients responded to the first line therapy with the overall response rate (ORR) of 72,7% including CR and PR in 4 (18,2%) and 12 (54,5%) patients respectively. Remaining patients had progression disease (n=5, 22,8%) and stable disease (n=1, 4,5%). The median course to achieve the ORR was 4 (2-6) cycles. Overall (OS) and progression-free survival (PFS) at 2 years after first line treatment was 59,1% and 40,9%, respectively. The median time to progression (TTP) was 7,95 (0,33-23,93) months. The addition of bortezomib and auto-HSCT in first line chemo improved OS (100% vs 47,1%, p=0,027), but non PFS (p=0,1) and TTP (p=0,4). Nine patients received second-line CT: DHAP - 4 (44,4%), ICE - 4 (44,4%), EPOCH - 1 (11,2%). Response was evaluated in 8 patients. CR, PR and progression disease was registered in 1 (12,5%), 2 (25%) and 5 (62,5%) patients respectively. PBSC harvesting was only successful in 1 of 3 cases (33%) and this patient received HDC with auto-HSCT. OS and PFS at 2 years after second line treatment was 44,4% and 22,2%, respectively. Two years after second line CT, 4 patients were still alive, including those after ICE, EPOCH (n=2), HDC with auto-HSCT (n=1) and nivolumab (27 cycles) as a third line therapy (n=1). Conclusions In a large cohort of patients PbL accounted for 8.9% of all HIV-related lymphomas. Bortezomib-containing chemotherapy and first line auto-HSCT show encouraging results, but data are obtained in a small group of patients. Prospective studies are needed for optimization of HIV-related plasmablastic lymphoma therapy. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: The is early clinical date on efficiency of Bortezomib in patients with plasmablastic lymphoma: https://doi.org/10.1111/bjh.15156

Optimizing pediatric peripheral blood stem cell collection

IntroductionPediatric PBSC harvests pose specific challenges during apheresis and a knowledge of the same and variables affecting PBSC collection are very important in planning these procedures. In the present study safety profile of pediatric PBSC procedures and variables influencing the successful collection were analyzed. MethodPediatric PBSC harvest data for 3 years was reviewed for donor, procedural and product parameters and any specific challenges faced during the procedures. Successful PBSC collection was defined when CD34 dose obtained was ≥2 × 106 cells/Kg of recipients’ body weight. Results85 PBSC collections performed on 46 children (age range 1.5–15 years) were included. Sixty-two procedures were on autologous donors and 23 on allogenic donors. The median CD34+ cell dose in the PBSC product per procedure was 2.12 × 106 cells/Kg for autologous procedures and 4.6 × 106 cells/Kg for allogenic procedures. Systemic adverse reaction was observed during only one procedure (0.01 %) and was managed conservatively. Successful dose was collected in 52 procedures (61.17 %) and was significantly associated with CD34+ count of more than 19.7/μL, monocyte count of more than 1.65 × 106/μL, allogenic collection and female gender (p = 0.00001, p = 0.011, p = 0.00052, and p = 0.0001, respectively). ConclusionPBSC collection is safe in pediatric age groups and pre-procedure CD34 count of ≥20/μL on the day of collection may result in successful collection of stem cell dose. It is important to identify factors associated with failed collection for appropriate counselling and justifying pre-emptive use of stem cell mobilizing agents.

Safety of peripheral blood stem cell harvest in children under anaesthesia in the day care setting – A single centre experience

The use of cytokine mobilized peripheral blood stem cells (PBSC) for stem cell transplantation offers early engraftment, and less early transplant related mortality and morbidity. This can be done easily in the out-patient setting in an adult donor, but is difficult in children. The safety and efficacy of general anaesthesia outside the controlled operation room setting is quite challenging and demanding. We present our experience with paediatric PBSC harvest done under anaesthesia in the out-patient setting between January 2009 to June 2017. A total of 158 children underwent 164 PBSC harvests during the study period. Donors were predominantly females with a median age of 5 years (1–12) and a median weight of 17.5 kg (9.4−51). In 50% of the cases, induction of anaesthesia was by sevoflurane followed by total intravenous anaesthesia (TIVA) while in 32% it was sevoflurane induction followed by sedation. Hudson mask (48.5%) and laryngeal mask airway (50%) were the most common modes of airway and all patients were ventilated in the spontaneous mode. Propofol was the most commonly used maintenance agent (67%). There were no major complications except for acute pulmonary edema secondary to infusion of blood products requiring a short stay in ICU for one donor. All donors were discharged on the next day of harvest. No long term complications have been reported in any of these donors. Paediatric PBSC harvest can be safely done under anaesthesia with due precautions in the day care setting.

Seasonal variation of human physiology does not influence the harvest of peripheral blood CD34+ cells from unrelated hematopoietic stem cell donors

There are many reports on factors predicting the outcome of PBSC (peripheral blood stem cell) mobilization, such as the donor’s gender, age, weight, white blood cell count, platelets pre apheresis, LDH and iron status. Although there are reports of seasonal variation in the physiology of the human immune system and hematopoiesis there are no data that such differences play a role in the response to G-CSF in healthy hematopoietic stem cell donors. The response to G-CSF could also impact the collection results during different seasons. To assess the possible impact of seasonal variation we performed a retrospective, single-center analysis of mobilization and harvest of PBSC in 330 healthy unrelated donors. We found no significant differences in the number of CD34+ cells in peripheral blood after G-CSF mobilization and in collection results when all donors were analyzed. In the subgroup of male donors the number of CD34+ stem cells after G-CSF mobilization was higher than average in summer and autumn (p = 0.036), however, it did not translate into clinically relevant differences in stem cell harvest.We conclude that although there is possible seasonal variation in the response to G-CSF in male donors there is no impact on PBSC harvest in healthy unrelated donors.

Peripheral Blood Stem Cell Harvest HPC Count Is an Effective Surrogate Marker for CD34+ Cell Count in Allogeneic Stem Cell Transplant Setting

OBJECTIVE: We assessed the predictive potential of XN-HPC for CD34+ cell count as obtained through Sysmex automated hematology analyzers (XN-1000). METHODS: This study was conducted at the National Institute of Blood Diseases and Bone Marrow Transplantation in 84 donors between December 2012 and December 2017 in the first phase and later validated in 112 donors between December 2017 and December 2018. Sysmex XN-1000 and BD FACS Calibur estimated XN-HPC and CD34+ cells of peripheral blood apheresis product, respectively. Spearman's correlation was assessed between XN-HPC and CD34+ cell count followed by receiver operating characteristic curve calculation to determine the XN-HPC cutoff for a CD34+ count of ≥2 million cells/kg of recipient's body weight RESULTS: There is a moderately positive correlation (P value = .003) between XN-HPC and CD34+ count. Receiver operating characteristic curve analyses demonstrated that a cutoff value for XN-HPC of ≥1·845×106cells/kg of recipient's body weight has a specificity and sensitivity of 100% and 78·2%, respectively, for predicting the CD34+ count of ≥2 million cells/kg of recipient's body weight. This cutoff value of XN-HPC was prospectively validated in 112 donors. The positive predictive value was found to be 100%, while negative predictive value was 17%. CONCLUSION: XN-HPC has a highly promising potential to serve as a cost-effective and time-saving surrogate for CD34+ cell count.

Hematopoietic stem cell donor with IgA nephropathy: Challenges and management algorithm

Donor safety is of prime importance in allogeneic hematopoietic cell transplantation. The Worldwide Network for Blood and Marrow Transplantation (WBMT) standing committee on donor issues has issued a consensus statement regarding suitability criteria for related adult donors. This committee recommends that donors with a history of immune-mediated glomerulonephritis and abnormal urine tests should preferably undergo bone marrow harvest, to avoid the theoretical risk of granulocyte colony-stimulating factor (G-CSF) induced immune flare-up. We discuss here a unique situation where a related donor with a history of IgA nephropathy (IgAN) insisted on a peripheral blood stem cell harvest. We propose a management plan for this situation, which posed challenges about donor suitability.

Comparing the outcome of progenitor (CD34+) Cell dose calculated using ideal body weight to actual body weight on engraftment of neutrophils and platelets after PBSC transplant

Background & Aim One of the most significant factors affecting the engraftment of a PBSC transplant is the cell dose of progenitor cells. Though it is commonly expressed in terms of CD34+ cells per kg actual recipient body weight(ABW), there are studies suggesting a cell dose calculated using ideal body weight(IBW) leads to faster engraftment of neutrophils and possibly platelets as well. A single centre, retrospective, observational study was carried out which compared the results for engraftment post allogeneic as well as autologous HSCT, using both these weight criteria. Methods, Results & Conclusion Material and Methods The study evaluated the data from 103 patients (autologous-76, allogenic- 27) who had undergone PBSC transplant for various disease conditions at our centre from Jan 2016 to Dec 2019 and had engrafted successfully. PBSC harvest was performed using COM.TEC (Fresenius Kabi AG, Germany) cell separator and CD 34+ enumeration was carried out as per ISHAGE guidelines using BD FACS Calibur (BD Biosciences, USA). IBW was calculated using the formula 50 + [2.3 X (Height in inches - 60)] for males and 45 + [2.3X (Height in inches - 60)] for females. The minimum required CD34+ cells/kg ABW was 2 × 106/kg. Time to neutrophil engraftment was defined as the number of days required to first achieve a neutrophil count ≥ 0.5 × 109/L after PBSC infusion and for platelet engraftment first of three continuous days with platelet count ≥ 20 × 109/L, without platelet transfusion. Statistical analysis was carried out using SPSS software(version 24, IBM). Results and Conclusion The median CD34+ (viable) cell count was 4.12 × 106/kg ABW and 4.86 × 106/kg IBW. The median time to neutrophil engraftment was 11 days while that for platelet was 13 days. The data was further analysed using non-parametric Mann Whitney U test and Spearman's Rank Correlation, on the entire group of patients as wells as subsets of autologous and allogeneic transplants. The dose of progenitor cells calculated using both IBW as well as ABW correlated with the time to engraftment. The Spearman's Rho(ρ) for neutrophil engraftment with IBW was 0.37 and with ABW was 0.33, which was statistically significant(p

CD26 as a Prognostic Marker in Allogeneic Hematopoietic Stem Cell Transplantation

Background: The success of hematopoietic stem cell transplantation (HSCT) depends upon donor stem cell harvest. Conventionally CD34 has been considered as marker of hematopoietic stem cells; however, the association of CD34+ cells with post-transplant outcomes has not been consistent. Current efforts are focused on identification of new markers that serve as potential predictors of post-transplant clinical outcome. Methods: This study includes donor harvests collected from twenty-three allogeneic donors during period 2008-2009 and respective transplant recipients followed for clinical outcomes till March 2019. Percent CD26+ and CD34+ cells in PBSC harvest were analyzed using flow cytometry. Infused dose of CD26+ and CD34+ cells was evaluated for its association with various clinical outcomes. Findings: Median donor and patient age was 28 and 24 years, respectively; 13 and 17 were males, respectively. Median CD34br CD45lo HSC expression was 0·57% (IQR 0·24-1·03) while median CD26 expression was 19·64% (IQR 8·96-33·56) of all nucleated cells. Lower CD26 expression correlated with lower risk of developing aGvHD (p=0·056). Higher infused CD26+ cell dose was associated with early WBC engraftment (p=0·004), higher risk of CMV reactivation (p=0·020) and a tendency to lower overall survival (p=0·066). There was no correlation between infused CD26+ and CD34+ cell dose. Interpretation: This forms the first study suggesting CD26 expression on donor harvest and CD26+ cell dose may serve as potential markers for transplant outcomes. If validated further in larger studies, it may be helpful in management of GvHD prophylaxis and improving survival with risk-based tailored therapeutics. Funding Statement: This study was funded by Indian Co-operative Oncology Network- Academic Research Organization, Mumbai, India. Declaration of Interests: Authors declare no potential financial conflicts of interest. Ethics Approval Statement: The study was approved by the institutional ethics committee. All patients and donors provided consent for study participation.

Mobilization Success and Bariers for Autologous Hematopoietic Stem Cell Transplantation in a Constrained-Resource Nation

<h3>Introduction</h3> Autologous stem cell transplantation (ASCT) is a well-established therapy for various hematologic and solid malignancies. Optimal mobilization and harvest of peripheral blood-stem cells (PBSC) is crucial. A failed mobilization attempt (MA) can preclude transplantation in up to 40% of cases, however, novel agents have increased success rates. The aim of our study was to evaluate factors impacting MA failure and remobilization efficacy in a resource-constrained setting. <h3>Methods</h3> Retrospective single-center study including patients with at least one MA of PBSC for ASCT between June 2010 to June 2019. <h3>Results</h3> Inclusion criteria were met by 158 patients. Median age at MA was 37y and 61.4% were male. ASCT indication was hematologic in 84.8%: lymphoma in 37.3%, monoclonal gammopathy in 32.9%, and acute leukemia in 14.6%. Relapsed or primary refractory disease was the indication in 51.9%. A 25.3% had previous exposure to radiotherapy. Status of disease at MA was in 48.1% complete response, while 8.9% (<i>n=14</i>) had less than a partial response (Figure 1). At first MA, the median level of CD34 was 16.1 × 10⁶/L. G-CSF, chemotherapy (CT) and plerixafor (PLX) were used in 85%, 11.8% and 3.2%. MA was successful (>2 or >4 × 10⁶ CD34/kg harvested in ≤3 aphereses) in 64.6% and 32.3%, with a median harvest in the whole cohort of 3.5 × 10⁶ CD34/kg (Figure 2). Factors associated with MA failure were: BMI ≥25 (<i>p=0.03</i>), high BSA (<i>p=0.016</i>), hematologic malignancy as ASCT indication (<i>p=0.013</i>), pre-MA WBC <4 × 10⁹/L (<i>p=0.032</i>), pre-apheresis CD34 <10 × 10⁶ cells/L (<i>p<0.001</i>), and MA with G-CSF or CT (<i>p=0.05</i>). No relation to CT regimens or number of cycles was seen except for lymphoma cases (<i>p=0.025</i>) (Figure 3). Of patients that failed MA, 66.1% (<i>n=36</i>) underwent a second MA. Of these, 85.3% were non-mobilizers to G-CSF and the remainder to CT. Of non-mobilizers to G-CSF, 44.8% (<i>n=13</i>) were rechallenged, to the remainder CT (37.9%) or PLX (17.2%) was added. Of non-mobilizers to CT, due to economic constraints or toxicity, 60% (<i>n=3)</i> received G-CSF while the remaining were rechallenged. Overall 41.7% and 19.4% cases had a successful second MA for >2 or >4 × 10⁶ CD34/kg, with no difference in outcome between mobilization agents used (<i>p=0.132)</i>. <h3>Conclusion</h3> In this cohort, anthropometry, hematologic disease, number of CT cycles, and WBC count; in addition to use of G-CSF as unique agent in MA was related to lower rates of successful PBSC harvesting. These findings should guide decision making process on mobilization agent, as limiting or delaying ASCT and requiring additional MA directly impact disease outcomes and higher costs. Reduced rates of success on second MA, despite increased use of CT and PLX were observed. The significant loss of benefit of PLX highlights the need to direct our efforts on preemptive action. Cost-effective, resource-stratified approaches are required to maximize adequate harvesting and subsequent access to ASCT.

Evaluation of the Sysmex XN automated hematopoietic progenitor cell enumeration for timing of peripheral blood stem cell harvest

BackgroundEnumeration of stem cells is essential in the management of peripheral blood stem cell (PBSC) harvest. An alternative to the gold standard flow cytometric CD34+ stem cell count is the fully automated hematopoietic stem cell (HPC) count on the Sysmex XN hematology analyzer. Materials and methodsEighty-nine patients and healthy stem cell donors who underwent PBSC harvest were included in the study. Stem cells were enumerated in pre-harvest peripheral blood and the apheresis yield by both flow cytometric CD34+ stem cell enumeration and by the Sysmex XN HPC count. ResultsThe Sysmex HPC concentration overestimated the CD34+ stem cell concentration by a ratio of 1.3 in average. The agreement between the two methods was poor at concentration <40 stem cells/μL (Bias: 45 %, 95 % limits of agreement: -71 - 160 %). CD34+ stem cell concentration and HPC concentration correlated well in pre-harvest peripheral blood (R=0.73, slope=0.96). We established a positive cut off >43.5 HPC/μL, where PBSC harvest can be initiated. And a negative cut off <16.5 HPC/μL, where harvest should be postponed or other mobilizing regimens or bone marrow harvest should be considered. 33 % of measurements were in between the negative and positive cut-off and would require a supplementary CD34+ cell count. ConclusionAlthough Sysmex HPC count correlates well with CD34+ cell count in peripheral blood, the agreement between the two methods is poor, especially at low concentrations, namely in the clinical decision range. Sysmex HPC count as a surrogate for CD34+ cell count should, therefore, be used with caution.

Allogeneic Peripheral Blood Stem Cell Transplant: Correlation of Donor Factors with Yield, Engraftment, Chimerism, and Outcome: Retrospective Review of a Single Institute During a 3-Year Period.

Donor factors have a variable correlation with cluster of differentiation (CD)34+ cell dose in allogeneic peripheral blood stem cell (PBSC) harvests. CD34+ cell dose affects the speed of hematopoietic recovery and percentage of donor chimerism in the recipient. A total of 25 allogeneic PBSC transplants performed during a 3-year period were included. All donors underwent mobilization with filgrastim. Leukapheresis, flowcytometric CD34+ cell enumeration, and chimerism analysis were performed and correlated with recipient outcome. Besides age, all other donor parameters had a positive correlation with CD34+ cell count. Engraftment kinetics and chimerism had a positive correlation with the CD34+ yield of the PBSC product. Acute graft-vs-host disease (GVHD) was observed in patients with complete chimerism at day 30 after transplantation. Adequate CD34+ cell yield happens in healthy donors, independent of donor demographic patterns with G-CSF only. A diverse population of donors can thus be approached for Matched Unrelated Donor (MUD) transplants. An accurate quantitative analysis of early donor chimerism in the recipient (at day 30) is an excellent tool for post-transplant monitoring for acute GvHD.

Dual Anticoagulant Facilitied Peripheral Blood Stem Cell Harvest from Childhood Donors with Low Weight and Low MCV

Background:Low weight children can sometimes be selected as donor in HSCT. Donor with thalassemia minor has low MCV, which affects peripheral blood stem cell (PBSC) harvest. It is worthwhile to explore a harvest program for donors with low body weight and low MCV. Objective:The aim of this study is to find out an appropriate program of PBSC collection in children with low body weight and low MCV. Methods:10 children, with median age of 2 (1-6) years, average weight of 13.4 (9.5- 20) kg and average MVC value of 63fl (54-78)) were hospitalized in our center from October 2018 to July 2019 for stem cell mobilization. Donor weight were less than recipients in 7 cases. 5 donors have 5 kg less than recipient, 3 have 10 kg less and 1 has 18 kg less, respectively. They received G-CSF of 5 mg/kg/d twice a day for 5 days before harvest. 500 ml ACD-A solution and 3000 IU heparin were mixed and given by the ratio of 1 ml mixed anticoagulant versus 24 ml whole blood. Blood-flow was 25-40 ml/min. Results:More 20/ul CD34+ cells were harvested in 9 cases (90%), and 19.2/ul in 1 case (10%). Median nucleated cells were13.2(6.7-22.4)x108/kg in donor weightand 9.8 (8.3-13.9) x108/kg in recipient weight. The median CD34+ cells were 5 (1.9-10.2) x106/kg in donor weight and 3.4 (1.4-9.7) x106/kg in recipient weight. The coagulation function was normal in reexamination. PBSC were harvested only once in all donors. Average circulating volume was 2.48 (1.14-5.79) total body volume, average harvesting time was 2.75 (2-6) hours, and average PBSC volume was 89 (63-160) ml. Donor peripheral blood calcium and potassium ion concentration showed no obvious abnormality. Conclusion:Combination of citrate and heparin can be well used to collect PBSC in donors with low body weight and low MCV. All children were well tolerance to the program, which was safe and effective for large volume collection of PBSC. Disclosures No relevant conflicts of interest to declare.

Exploring the Safety and Efficacy of Upfront Autologous Stem Cell Transplantation with LEED Preconditioning for Primary Central Nervous System Lymphoma

Exploring the Safety and Efficacy of Upfront Autologous Stem Cell Transplantation with LEED Preconditioning for Primary Central Nervous System Lymphoma

Safety and Toxicity Profile of Pembrolizumab (PEM) in Combination with ICE Chemotherapy Followed By Autologous Stem Cell Transplantation for Relapsed/Refractory Classical Hodgkin Lymphoma: No Impairment in Stem Cell Mobilization or Engraftment

Background: Despite excellent outcomes in the front-line management of classical Hodgkin lymphoma (cHL), patients with relapsed or refractory disease typically undergo second-line cytotoxic chemotherapy before proceeding to consolidation with autologous hematopoietic stem cell transplant (autoHSCT). Pre-transplant F18-FDG-PET imaging is a well-established predictor of outcomes following autoHSCT; a complete metabolic response (CMR) to second-line therapy defined as a Deauville score 1-3 predicts a favorable outcome and is a requirement for transplant at many centers. The PD-1 pathway plays an important role in the pathogenesis of cHL and checkpoint inhibition with agents including PEM and nivolumab have shown efficacy as monotherapy in heavily pretreated disease. We hypothesized that the addition of PEM to ICE (ifosfamide, carboplatin, and etoposide) chemotherapy will increase the rate of CMR by PET-CT prior to autoHSCT without impairing the mobilization of peripheral blood progenitor cells (PBPC) or engraftment. Here we present interim safety and toxicity data from this ongoing trial (NCT03077828) including the yields of PBPC mobilization and engraftment. Methods: Enrollment criteria include patients age &gt;18 years medically fit for autoHSCT with relapsed/refractory cHL and excludes those with prior PD-1 inhibitor exposure, CNS involvement, more than 2 prior regimens or history of autoimmune disease. Patients are treated with 2 cycles of PEM 200 mg IV on day 1 in combination with ICE chemotherapy (ifosfamide 5000 mg/m2 day 2 CIV over 24hr, carboplatin AUC 5 IV day 2, etoposide 100 mg/m2 IV days 1-3) on a Q21 day cycle. PBPC mobilization and harvest are performed per institutional protocol on recovery post-cycle #2. A cycle of PEM 200 mg IV is then administered as monotherapy followed by response assessment with PET-CT. Patients with Deauville scores ≤3 proceed to autoHSCT per institutional protocol. A third cycle of PEM+ICE is optional following the PET-CT assessment. Neither the conditioning regimen nor management during transplantation is dictated by the protocol. Results: As of July 2019, 23 of 40 planned patients have evaluable safety and toxicity data. One patient had inconclusive pathology and was removed from study after one cycle of PEM-ICE but is included for this report. The median age was 32 (range 19-62) and 17 of 23 patients were females (74%). 8 patients were refractory to first-line therapy, and 9 relapsed within one year of treatment. 19 patients had received ABVD. Following protocol directed therapy, all but one patient had successful mobilization and collection; one had a severe allergic reaction to filgrastim and underwent bone marrow harvest instead. 16 patients collected in a single day of apheresis; the remainder collected within 4 days. The median number of stem cells harvested was 12.6 x 106 CD34+ cells/kg (range 4.2 - 46.1 x 106/kg). 3 patients underwent the 3rd cycle of PEM + ICE chemotherapy. 3 patients had Deauville scores &gt;3 on FDG-PET response assessment; two had biopsies showing only benign processes and proceeded to transplant. Following stem cell reinfusion, all patients successfully engrafted, with a median time to absolute neutrophil and platelet recovery of 11 days (range: 9 - 24) and 12 days (range: 9 - 23), respectively. The combination of PEM + ICE chemotherapy was well tolerated. There were no reports of pneumonitis, colitis, hepatitis, or endocrinopathies. The most common toxicities were cytopenias, mucositis, diarrhea and febrile neutropenia. A single death on protocol was deemed secondary to advanced cardiovascular disease discovered mid-treatment during the patient's pre-transplant assessment. There was no clinical evidence to suggest an inflammatory process resulting in the cardiac arrest. Conclusions: The combination of PEM with ICE chemotherapy in relapsed / refractory cHL appears tolerable and safe. We found no significant hindrance to peripheral blood stem cell harvest and PEM- related AEs were uncommon. Additionally, pre-treatment with a checkpoint inhibitor prior to autoHSCT appears safe thus far and does not appear to delay engraftment. Disclosures Casulo: Celgene: Research Funding; Gilead: Honoraria, Other: Travel, accommodation, expenses; Roche: Other: Travel, accommodation, expenses. Karmali:Takeda, BMS: Other: Research Funding to Institution; Gilead/Kite; Juno/Celgene: Consultancy, Speakers Bureau; Astrazeneca: Speakers Bureau. Pro:Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other: Travel Expenses; Kyowa Hakka Kirin: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Mehta:Millennium/Takeda, Celgene; stock in Celgene, Bristol-Myers Squibb and Bluebird: Speakers Bureau. Gordon:Bayer: Other: Advisory Board; Juno/Celgene: Other: Advisory Board, Research Funding; Gilead: Other: Advisory Board; Zylem LLC: Other: co-founder; research in nanoparticles in cancer. Winter:Merck: Consultancy, Research Funding.

Hematopoietic Stem Cell Expansion

Abstract Hematopoietic stem cell transplants (HSCT) are now an established practice with over 70,000 transplants performed annually, and over 1.5 million around the world so far. The practice of HSCT has improved over the years due to advances in conditioning regiments, preparatory practices for the patients leading up to the transplant, graft versus host disease (GVHD) and infection prophylaxis as well as a better selection of patients. However in many instances, there could be inadequate stem cells supplied to the patient for optimal transplantation outcomes. This may be seen in a few areas including umbilical cord blood transplantation (UCBT), inadequate bone marrow (BM) or peripheral blood (PB) stem cell harvest as well as gene therapy (GT). Growing and expanding HSCs in culture will allow us to be able to increase cell numbers prior to stem cell infusion and hopefully accelerate haematopoietic recovery, resulting in improved outcomes. Several new technologies have emerged in recent years, allowing us to expand haematopoietic stem and progenitor cells (HSPC) in culture with good outcomes in vitro, in vivo and in clinical trials. In this lecture, we will outline some of the reasons for HSPC expansion as well as the new technologies that are enabling this quantum leap in HSCT. We also present novel molecule, C7, that promotes dramatic and superior expansion of phenotypically (CD45+/CD34+/CD38-/CD90+/CD49f/CD90+) and functionally (CFU-GM, LTCIC, SRC, long term NSG engraftment as well as engraftment of secondary mice) defined hematopoietic stem cells, and that shows significant promise for clinical applications.

Rationale and design of the German-speaking myeloma multicenter group (GMMG) trial HD6: a randomized phase III trial on the effect of elotuzumab in VRD induction/consolidation and lenalidomide maintenance in patients with newly diagnosed myeloma

BackgroundDespite major advances in therapy, multiple myeloma is still an incurable malignancy in the majority of patients. To increase survival, deeper remissions (i.e. CR) translating into longer PFS need to be achieved. Incorporation of new drugs (i.e. bortezomib and lenalidomide) as induction and maintenance treatment in an intensified treatment concept, including high dose melphalan (200 mg/m2), has resulted in increased CR rates, and is considered the standard of care for younger patients. Elotuzumab in combination with lenalidomide and dexamethasone has given better results as lenalidomide and dexamethasone alone in a phase III trial. The GMMG-HD6 trial will be the first phase III trial investigating the role of elotuzumab in combination with bortezomib, lenalidomide and dexamethasone (VRD) induction/consolidation and lenalidomide maintenance within a high dose concept.MethodsGMMG-HD6 is a randomized, open, multicenter phase III trial. The planned recruitment number is 564 NDMM patients. All patients will receive 4 VRD cycles as induction and undergo peripheral blood stem cell mobilization and harvesting. Thereafter they will be treated with high dose melphalan therapy plus autologous stem cell transplantation followed by 2 cycles of VRD consolidation and lenalidomide maintenance. Patients in arm B1 + B2 will additionally receive elotuzumab in the induction phase, whereas patients in A2 + B2 will be treated with elotuzumab added to consolidation and maintenance. The primary endpoint of the trial is PFS. Secondary objectives and endpoints are OS, CR rates after induction therapy comparing the two arms VRD (A1 + A2) vs VRD + elotuzumab (B1 + B2), CR rates after consolidation treatment, best response to treatment during the study, time to progression (TTP), duration of response (DOR), toxicity and quality of life.ResultsSince this is the publication of a study protocol of an ongoing study, no results can be presented.DiscussionThis phase III trial is designed to evaluate whether the addition of elotuzumab to an intensified treatment concept with high dose melphalan chemotherapy plus autologous stem cell transplantation and induction, consolidation and maintenance treatment with bortezomib and lenalidomide is able to improve PFS compared to the same concept without elotuzumab.Trial registrationNCT02495922 on June 24th, 2015.

Phase 1 study of elotuzumab in combination with autologous stem cell transplantation and lenalidomide maintenance for multiple myeloma.

8021 Background: Elotuzumab is a humanized monoclonal antibody directed against SLAMF7 that is approved for use in relapsed multiple myeloma. We initiated a single-center, open label, phase 1 trial based on the hypothesis that the addition of elotuzumab and autologous peripheral blood mononuclear cell (PBMC) reconstitution to standard-of-care autologous hematopoietic stem cell transplantation (auto-SCT) and lenalidomide maintenance for consolidation therapy in myeloma patients will be safe and feasible. Methods: This is a Phase 1b, open-label, trial investigating elotuzumab and autologous PBMC reconstitution with auto-SCT consolidation therapy and lenalidomide maintenance. The primary objective of this study is to assess the safety and tolerability of elotuzumab and autologous PBMC reconstitution in the setting of auto-SCT and lenalidomide maintenance. The secondary objectives are to assess myeloma disease status and progression-free survival (PFS) after one year of treatment. Subjects must be eligible for auto-SCT, and meet inclusion/exclusion criteria. Fifteen subjects participated in this study. The treatment plan is: In addition to PBSC harvest, subjects undergo steady-state leukopheresis for PBMC collection. Subjects receive standard melphalan (day -1) and autologous stem cell rescue (day 0). Autologous PBMC are reinfused on day +3 and cycle 1 of elotuzumab 20 mg/kg IV is given on day +4. Subjects receive elotuzumab every 28 days up to cycle 12. Lenalidomide maintenance at 10 mg orally daily begins with cycle 4 of elotuzumab. The evaluable population constitutes all subjects who received at least four of the first five planned doses of elotuzumab. Results: 15 subjects have been enrolled in the study. All of these subjects are included in the safety population, having received at least 1 dose of elotuzumab. Nine of 15 subjects have completed 4 of the first 5 planned elotuzumab infusions.. The majority of adverse events, including infusion reactions attributable to elotuzumab, have been grade 2 or lower. There were no delays in hematopoietic reconstitution. No AEs were attributed to PBMC reconstitution. Conclusions: The combination of elotuzumab and PBMC reconstitution with standard auto-SCT and lenalidomide maintenance for consolidation therapy appears to be safe and feasible. The trial is ongoing and has completed accrual. The clinical results will be updated for presentation.