Hematopoietic Stem Cell Harvest Research Articles

Poor Mobilization-Associated Factors in Autologous Hematopoietic Stem Cell Harvest.

Peripheral blood stem cell transplantation (PBSCT) is an important therapeutic measure for both hematologic and non-hematologic diseases. For PBSCT to be successful, sufficient CD34+ cells need to be mobilized and harvested. Although risk factors associated with poor mobilization in patients with hematologic diseases have been reported, studies of patients with non-hematologic diseases and those receiving plerixafor are rare. To identify factors associated with poor mobilization, data from autologous PBSC harvest (PBSCH) in 491 patients were retrospectively collected and analyzed. A multivariate analysis revealed that in patients with a hematologic disease, an age older than 60 years (odds ratio [OR] 1.655, 95% confidence interval [CI] 1.049-2.611, p = 0.008), the use of myelotoxic agents (OR 4.384, 95% CI 2.681-7.168, p < 0.001), and a low platelet count (OR 2.106, 95% CI 1.205-3.682, p = 0.009) were associated with poor mobilization. In patients with non-hematologic diseases, a history of radiation on the pelvis/spine was the sole associated factor (OR 12.200, 95% CI 1.934-76.956, p = 0.008). Among the group of patients who received plerixafor, poor mobilization was observed in 19 patients (19/134, 14.2%) and a difference in the mobilization regimen was noted among the good mobilization group. These results show that the risk factors for poor mobilization in patients with non-hematologic diseases and those receiving plerixafor differ from those in patients with hematologic diseases; as such, non-hematologic patients require special consideration to enable successful PBSCH.

Interference of daratumumab and efficacy of plerixafor on haematopoietic stem cell collection in Multiple Myeloma

The impact of daratumumab on CD34+ hematopoietic stem cell (HSC) mobilization has recently been a matter of concern. To address this issue, we compared CD34+ HSC-related outcomes in patients with multiple myeloma treated with daratumumab-based quadruplets (N = 44) and bortezomib/thalidomide/dexamethasone (N = 50) before cyclophosphamide-based mobilization. Plerixafor was more often required in the daratumumab group (52% vs. 20%, p = 0.002) and, despite a lower total yield, retained its efficacy in boosting HSC harvesting (+90% vs. +79%, p = 0.463). As a result, the same proportion of patients reached their planned collection goal in the two groups, suggesting its potential to overcome the interference of daratumumab on HSC mobilization. No clinically significant differences were observed in the immediate post-autologous HSC transplant interval in the two groups.

Effect of prior lenalidomide or daratumumab exposure on hematopoietic stem cell collection and reconstitution in multiple myeloma.

The roles of Lenalidomide (Len) and Daratumumab (Dara) in multiple myeloma treatment are well-established, yet their influences on hematopoietic stem cell harvesting and reconstitution remain disputed. We conducted a systematic database review to identify cohort studies or RCTs evaluating the effect of the use of Len or Dara on hematopoietic stem cell collection and peripheral blood count recovery in multiple myeloma patients. Effects on hematopoietic collection or reconstitution were estimated by comparing standardized mean differences (SMD) and mean differences (MD), or median differences. Eighteen relevant studies were identified, summarizing mobilization results. For Len, data from 13 studies were summarized, including total CD34+ cell yield, collection failure rate, and time to neutrophil and platelet engraftment. Results indicated that Len exposure led to decreased stem cell collection [SMD=-0.23, 95% CI (-0.34, -0.12)]. However, collection failure (<2×106) could be mitigated by plerixafor [OR=2.14, 95% CI (0.96, 4.77)]. For Dara, two RCTs and three cohort studies were included, showing that Dara exposure resulted in a reduction in total stem cells even with optimized plerixafor mobilization [SMD=-0.75, 95% CI (-1.26, -0.23)], and delayed platelet engraftment recovery [MD=1.20, 95% CI (0.73, 1.66)]. Our meta-analysis offers a comprehensive view of Len and Dara's impacts on hematopoietic stem cell collection and reconstitution in multiple myeloma. Len usage could lead to reduced stem cell collection, counteracted by plerixafor mobilization. Dara usage could result in diminished stem cell collection and delayed platelet engraftment.

A prospective, multicenter study on hematopoietic stemcell mobilization with cyclophosphamide plus granulocyte colony-stimulating factor and 'on-demand' plerixafor in multiple myeloma patients treated with novel agents.

High-dose melphalan plus autologous stem cell transplantation (ASCT) is a standard of care for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM), and adequate hematopoietic stem cell (HSC) collection is crucial to ensure hematologic recovery after ASCT. In this prospective, observational study we evaluated HSC mobilization with granulocyte colony-stimulating factor (G-CSF), cyclophosphamide, and 'on-demand' plerixafor (in patients with <20×106 CD34+ cells/L after at least 4 days of G-CSF or failing to collect ≥1×106 CD34+ cells/kg after the first apheresis) in NDMM patients treated with novel agent-based induction therapy. The primary endpoint was the rate of poor mobilizers (patients collecting <2×106 CD34+ cells/kg or requiring plerixafor rescue to reach an adequate HSC harvest). Secondary endpoints included the rate of patients collecting ≥2×106 CD34+ cells/kg after plerixafor administration and the identification of factors predicting mobilization failure or plerixafor need. Overall, 301 patients (median age 60 years) were enrolled. Two hundred and eighty-seven of 301 (95%) and 274 of 301 (93%) patients collected ≥2×106 and ≥4×106 CD34+ cells/kg, respectively, with a median of 9.9×106 CD34+ cells/kg collected. Poor mobilizers were 48 of 301 (16%): 34 of 301 (11%) required plerixafor rescue, and 14 of 301 (5%) failed HSC collection regardless of plerixafor. Thirty-four of 38 (90%) patients receiving plerixafor collected ≥2×106 CD34+ cells/kg. Bone marrow plasmacytosis at diagnosis >60% (odds ratio [OR]=4.14), lenalidomide use (OR=4.45), and grade 3-4 hematologic toxicities during induction (OR=3.53) were independently associated with a higher risk of mobilization failure or plerixafor need. Cyclophosphamide plus G-CSF and 'on-demand' plerixafor is an effective strategy in NDMM patients treated with novel agents, resulting in a high rate of HSC collection and high HSC yield (clinicaltrials gov. identifier: NCT03406091).

Impact of Daratumumab on Hematopoietic Stem Cell Mobilization with G-CSF and on-Demand Plerixafor in Newly-Diagnosed Multiple Myeloma Patients

Introduction Autologous stem cell transplantation (ASCT) is a standard of care for transplant eligible (TE) patients with newly diagnosed (ND) multiple myeloma (MM); therefore, an adequate hematopoietic stem cell (HSC) collection is crucial to allow patients to proceed to ASCT and ensure optimal hematologic recovery. A more frequent use of plerixafor (PLX) and lower HSC yields have been reported in patients treated with daratumumab, a backbone of induction therapy for NDMM patients. Chemotherapy-free mobilization with G-CSF and on-demand PLX is an effective mobilization strategy lacking chemotherapy-related toxicities. Here we present the results of a multicenter, retroprospective and prospective, observational study, aiming to compare the impact of daratumumab on HSC mobilization with G-CSF + on-demand PLX in patients with NDMM treated with bortezomib-thalidomide-dexamethasone (VTd) or VTd plus daratumumab (D-VTd). Methods NDMM patients undergoing a first HSC mobilization attempt with G-CSF (10 mcg/kg/day) were enrolled and observed up to 30 days after ASCT. According to its label, on-demand PLX was administered in patients with &amp;lt;20 CD34 + cells/µL after ≥ 4 days of G-CSF or in case &amp;lt;1×10 6 CD34 + cells/kg were collected on the first day of apheresis. The primary endpoint of the study was the rate of poor mobilizing patients (≤2x10 6 CD34 + cells/Kg collected or need for PLX to reach an adequate HSC harvest). Key secondary endpoints included: the rate of suboptimal (2 to 4 CD34 + cells/kg) and optimal (≥4 CD34 + cells/Kg) collection; the median number of apheresis required to obtain ≥2x10 6 CD34 + cells/Kg; the impact of daratumumab on HSC engraftment. Results A total of 190 NDMM patients (median age, 62 years) were enrolled in 2 Italian centres (IRCSS Istituto Clinico Humanitas and Città della Salute e della Scienza di Torino) and analyzed; of these, 70% (133/190) were treated with VTd and 30% (57/190) with D-VTd. The median number of induction cycles was 4 in both groups. Best response after the induction phase was at least very good partial response (VGPR) in 87/133 (65%) and 41/57 (72%) of patients treated with VTd or D-VTd, respectively (p=0.4). The median time from the end of induction to G-SCF administration was 24 days in the VTd group and 29 days in the D-VTd group (p=0.5). The rate of poor mobilizing patients was 31% (41/133) in the VTd group and 54% (31/57) in the D-VTd group (p=0.002), mainly due to a higher rate of PLX use in the D-VTd as compared to the VTd group (53% vs. 28%; p=0.001), while the rate of patients who failed HSC mobilization (≤2x10 6 CD34 + cells/kg collected) was similar in the two groups (2% vs. 3%; p=1). Despite a numerically higher median number of CD34 + cells collected in the VTd group (7.9) as compared to the D-VTd group (7.1; p=0.009), no difference in the rate of patients who collected 2-4 (5% vs. 5%; p=1) and ≥4 CD34 + cells/Kg (95% vs. 95%; p=1) was observed in the VTd and D-VTd groups, respectively. A higher median number of CD34 +/µL on the first day of count was observed in the VTd as compared to the D-VTd group (24.5 vs. 19, p=&amp;lt;0.001). Among patients who had &amp;lt;20 CD34 +/µL [32% (43/133) vs. 51% (29/57)] on the first day of count, a similar increase in the CD34 +/µL (48.5 vs. 55) was observed in the two groups after PLX administration. The median number of apheresis session needed to complete the harvestwas 1 fo the VTd group and 2 in the D-VTd group (p=0.1). Neutrophil and platelet recovery were achieved in 100% of patients with a median time to neutrophil recovery of 15 and 13 days in the VTd and D-VTd groups, respectively (p=&amp;lt;0.001) and a median time to platelet recovery of 16 and 14 days in the VTd and D-VTd groups, respectively (p=0.001). Conclusion G-CSF plus on-demand PLX for HSC mobilization demonstrated to be an effective strategy in NDMM patients treated with VTd with or without daratumumab, resulting in very low rates of mobilization failures irrespective of the use of daratumumab during induction. Despite a higher rate of patients requiring PLX for HSC collection and lower CD34 + yields, the incorporation of daratumumab as part of the induction treatment did not negatively impact the possibility to achieve an optimal HSC collection. Our results, along with the lack of chemotherapy-associated toxicity, support the use of a chemotherapy-free HSC mobilization with G-CSF and on-demand plerixafor also in patients receiving daratumumab upfront.

Dexmedetomidine for sedation during hematopoietic stem cell harvest apheresis and leukapheresis in the PICU: Guideline development

BackgroundHematopoietic stem cell (HSC) harvest apheresis and leukapheresis are performed in the pediatric intensive care unit (PICU) for high-risk pediatric patients who require procedural sedation. Patients need central access either with their own central lines, ports or require apheresis catheter (CVL) placement. Previously, patients were either awake or emerging from sedation on PICU admission. Uncertainty regarding procedural sedation plans caused delays initiating sedation and apheresis. A guideline was developed to standardize Dexmedetomidine (DEX) for procedural sedation. We investigated if guideline implementation would improve efficiency during PICU admission as demonstrated by shorter time intervals for initiation of sedation, apheresis, PICU length of stay and less alternative sedating medication. MethodsData was collected retrospectively from electronic health records of preguideline and post-guideline patients who were admitted to the PICU for sedated apheresis. We compared demographic and clinical characteristics, time intervals for sedation, apheresis, PICU length of stay, and sedation agents between the two groups using Fisher Exact tests and Mann-Whitney tests, as appropriate. ResultsThe groups did not differ in age or weight at the time of apheresis. All intervals of time compared were shorter post-guideline. Time intervals from admission to start of sedation, admission to start of apheresis, and admission to end of apheresis were statistically significantly different. The type and number of alternative sedating medications administered did not differ between the two groups. ConclusionThis guideline implementation improved efficiency during PICU admission. This study might have been too small to demonstrate statistically significant differences in other time intervals studied.

Moral Distress: Its Manifestations in Healthy Donors during Peripheral Blood Hematopoietic Stem Cell Harvesting

Hematopoietic stem cell donors (HSCDs) may have ambivalent feelings about donation. These feelings are related to moral obligation to help a sick relative and/or fear about the donation procedure. This ambivalence can produce moral distress (MD) and anxiety, which are usually unnoticed by the treating physician. The aim of this study was to evaluate the incidence of MD and anxiety in a group of related HSCDs for allogeneic transplantation. In this prospective observational study, to assess MD and anxiety, we applied 3 self-answered questionnaires-a questionnaire developed to assess MD (MDQ), State Trait Anxiety Index (STAI), and Edmonton Symptom Assessment System (ESAS)-before, during, and after hematopoietic stem cell donation. A total of 60 consecutive related HSCDs with a mean age of 38.2 years were included. Thirty-six were male. Hematopoietic stem cell collections were done by apheresis, performed as an outpatient process in all cases. The incidence of MD during the donation process was 56%. The proportion of HSCDs with moderate to high state anxiety decreased significantly from before donation (63%) to after donation (30%). Higher scores for MD correlated with higher scores on the STAI questionnaire (r=0.448; P < .005). Thirty-seven donors (62%) had at least 1 physical symptom even before the stem cell mobilization process started, mainly anxiety (33%), difficulty sleeping (33%), and fatigue (30%). The number of symptomatic donors increased during donation (100%) and decreased after the procedure (80%). We conclude that MD and anxiety symptoms experienced by HSCDs are very common and can be explained by mixed feelings about the donation process. Providing comprehensive psychological support before starting the donation process and guaranteeing respect for the donor's autonomy are needed to decrease the negative impact of the donation experience.

AMD3100 redosing fails to repeatedly mobilize hematopoietic stem cells in the nonhuman primate and humanized mouse

AMD3100 (plerixafor) is a vital component of many clinical and preclinical transplant protocols, facilitating harvest of hematopoietic stem and progenitor cells through mobilization into the peripheral blood circulation. Repeat mobilization with AMD3100 is also necessary for many patients with suboptimal first stem cell collection or those requiring repeat transplantation. In this study we investigated the mobilization efficacy of repeated AMD3100 dosages in the nonhuman primate and humanized mouse models. In nonhuman primates, we observed effective mobilization after the first AMD3100 administration but a significantly poorer response in CD34+ and hematopoietic stem cell-enriched CD90+ cells with subsequent doses of the drug. A similar loss of efficacy with repeated administration was noted in immunodeficient mice engrafted with human CD34+ cells, in whom the total human white cell population, and particularly human hematopoietic stem and progenitor cells, mobilized significantly less effectively following a second AMD3100 administration when compared with the first dose. Together, our results are expected to inform future mobilization protocols for the purposes of peripheral blood hematopoietic stem cell extraction or for applications in which hematopoietic stem cells must be made accessible for in vivo-delivered gene targeting agents.

Hematopoietic Stem Cell Transplantation and Brentuximab Vedotin for Patients with Relapsed or Refractory Hodgkin Lymphoma and Systemic Anaplastic Large-Cell Lymphoma.

Brentuximab vedotin (BV) is an antibody–drug conjugate that has demonstrated effectiveness as a monotherapy for patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large-cell lymphoma via several clinical trials. Salvage chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplantation (HSCT) has been performed as a second- or later-line regimen for improving the survival of patients with lymphoma. In particular, the effectiveness of autologous HSCT and the importance of achieving a complete response prior to autologous HSCT are established in Hodgkin lymphoma. Several clinical trials have reported that salvage chemotherapy followed by autologous HSCT showed high response rates, although significant treatment-related hematological toxicity was observed. In the present article, we review clinical reports for assessing the efficacy and safety of relatively less toxic BV as a bridging therapy before HSCT or as a consolidation therapy post-HSCT in patients with relapsed or refractory Hodgkin lymphoma or systemic anaplastic large-cell lymphoma. Generally, the reported BV regimens seem to be effective and well tolerated in such patients, and no significant influence of BV treatment is noted on hematopoietic stem cell harvest before HSCT. Large-scale clinical studies and long-term follow-up are expected to establish the safety and efficacy of these regimens.Funding: Takeda Pharmaceutical Co., Ltd., Tokyo, Japan.

Improved progression-free and event-free survival in myeloma patients undergoing PBSCH receiving a cyclophosphamide+G-CSF regimen than G-CSF alone.

Two regimens are commonly used for peripheral blood hematopoietic stem cell harvesting (PBSCH) in multiple myeloma: high-dose cyclophosphamide (HD-CY)+granulocyte-colony stimulating factor (G-CSF), and G-CSF alone. The objective of the present study was to evaluate the anti-myeloma effect of the PBSCH regimen including HD-CY. We retrospectively assessed harvesting efficiency, complications, and anti-myeloma effects in 115 patients receiving HD-CY+G-CSF (HD-CY group) and 32 patients receiving G-CSF alone (G-alone group). We collected>2×106 CD34-positive cells/kg from 93 and 75% of patients in the HD-CY and G-alone groups, respectively (P=0.0079). The mean HSC count was also higher in the HD-CY group. No severe complications were observed in the G-alone group, whereas 66% of patients in the HD-CY group were treated with intravenous antibiotics. The median progression-free and event-free survival (PFS and EFS) were longer in the HD-CY group than in the G-alone group (28 vs. 18months and 25 vs. 13months, respectively; P=0.0127 and 0.0139), with no difference in median overall survival. HD-CY showed anti-myeloma effect, as verified by prolonged EFS and PFS, when a vincristine, doxorubicin, and dexamethasone regimen was administered as induction before PBSCH.

Stem Cell Mobilization and Harvesting Failure in Case of Heavily Pretreated Patients

Abstract Background: High-dose chemotherapy and autologous stem cell transplantation have become a standard curative treatment in various hematologic malignancies. Many factors can affect the success of mobilization and hematopoietic stem cell harvesting. Aim: The aim of this study was to analyze factors that lead to mobilization failure. Material and Methods: We conducted a retrospective study on 19 patients with failure of stem cell harvesting. All patients were administered high doses of GCS-F (filgrastim, 15 μg/kg/day) and 0.24 mg/kg of plerixafor on day +5 or +10 of harvesting. Results: The median age of the study population was 51 years (range 35–67) and 52.6% (n = 10) were males. The study group included 4 (21%) subjects with multiple myeloma, 6 (31.5%) with Hodgkin lymphoma, 8 cases (42.1%) with non-Hodgkin lymphoma and 1 patient with chronic lymphocytic leukemia. Each patient received 2.78 (range 1–5) lines of chemotherapy, administered in 11.57 (range 2 to over 20) cycles of treatment. Conclusion: In hematologic malignancies it is very important to collect stem cells in time, in order to reduce mobilization failure. As we have shown in our studied cases, multiple lines of polychemotherapy with or without radiotherapy lead to mobilization failure.

753. Lentiviral-Mediated Gene Correction of Mobilized Peripheral Blood Progenitors and Repopulating Cells from FA-A Patients

Fanconi anemia (FA) is an inherited disease mainly characterized by congenital abnormalities, progressive bone marrow failure and cancer predisposition. Based on previous FA gene therapy studies we aimed at improving the therapeutic efficacy of gene therapy in FA-A patients using optimized protocols of hematopoietic stem cell (HSC) harvesting and transduction. The mobilization regimen consisted on the administration of G-CSF (neupogen; 12 µg/Kg/12 hours) and plerixafor (mozobil; 240 µg/kg body weight/day). Two out of six patients with 15 and 16 years old did not reach the threshold level of CD34+ cells in PB, and therefore, apheresis was not conducted. In the four youngest patients, the total number of collected CD34+ cells/kg ranged between 1.6×106 to 7.6×106 (8.6×105 to 5.1×106 CD34+ cells/Kg after purification), and were cryopreserved for clinical use. The short transduction of small aliquots of mPB CD34+ samples from these patients with a GMP-produced lentiviral vector that harbors the FANCA therapeutic gene showed transduction efficacies between 20-40%, measured by the survival of transduced colony forming cells (CFCs) to mitomycin C (MMC). To assess the repopulating ability of transduced FA-A CD34+ cells, aliquot samples were transplanted into NSG mice conditioned with 1.5 Gy. Remarkably, most of the transplanted samples engrafted into the NSG mice (1-10% of the BM cells were hCD45+/mCD45−). Moreover, a selection advantage of corrected CD34+ FA-A cells was observed in engrafted mice, as deduced from the high MMC-resistance of hCFCs obtained from recipients’ BM. Our results show for the first time that clinically applicable transduction protocols can correct the phenotype of human FA-A hematopoietic repopulating cells. Currently a gene therapy trial of FA-A patients based on the ex vivo transduction of mPB CD34+ cells with lentiviral vectors is open in our Institutions.

Circulating hematopoietic progenitors and CD34+ cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

BackgroundPrevious studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC) and CD34+ cell are positively correlated with CD34+ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34+ cells required for performing an efficient hematopoietic stem cell (HSC) harvest in lymphoma and myeloma patients have not been defined in our institution.Patients and methodsMedical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×106 CD34+ cells/kg and ≥5×106 CD34+ cells/kg, respectively.ResultsThe minimally required or optimal HSC yield obtained was not influenced by age (≥60 years), sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34+ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34+ cell) and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34+ cell). The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm3 for HPCs and 10/mm3 for CD34+ cells. Furthermore, the cell count cutoff for obtaining optimal HSC harvest was determined to be 60/mm3 for HPCs and 35/mm3 for CD34+ cells.ConclusionA total of 60/mm3 of HPCs and 35/mm3 of CD34+ cells in peripheral blood predicted optimal HSC harvest in lymphoma and myeloma patients.

The Safety of Hematopoietic Stem Cell Harvest from Elderly Family Donor in Japan

[Background and Objectives]The number of patients received allogeneic hematopoietic stem cell (HSC) transplantation is increasing year by year, particularly for elderly patients. Related donor is preferable than the unrelated, but the safety of elderly donors has not been clarified. For this purpose, the complications of elderly HSC donor were retrospectively analyzed in comparison with younger donors.[Materials and Methods]From September 2006 to December 2014, a total of 7,896 related HSC donations was reported to the Japan society for hematopoietic cell transplantation (JSHCT) registration system by 391 harvest teams. The day 30 check reports after harvest were available for 6,911 (87.5%) donations. Donors under 18 years old were excluded, and 6,297 donations were analyzed in the present study. For donor age analysis those ranging from 18 to 30 years were regarded as reference. The primary endpoint was the incidence of early severe adverse events (eSAEs) during the harvest or within the 30-day period. Statistical analyses were conducted using Fisher's exact test to compare the donor demographics and to identify the relationships between the incidence of eSAEs. Logistic regression analyses were used to analyze the factors influencing eSAEs. Data analyses were conducted using EZR software, version 1.23 (Saitama Medical Center, Jichi Medical University). This study was approved by the ethical committee of JSHCT and Shimane University.[Results]Median age of donors were 42 years old (range: 18-80). There were 3,232 male and 3,002 female donors. A total of 2,009 donations were planned to collect bone marrow (BM) and 4,288 donations were planned to collect peripheral blood stem cell (PBSC). Nine of the planned BM harvests and 64 of the planned PBSC collections were cancelled because of the various reasons including adverse reactions or poor stem cell mobilization. Three other donations planned to collect BM were changed to PBSC, and four donations planned to collect PBSC were changed to BM, vice versa. These altered cases were included to the analysis as an intention-to-harvest basis. Out of 6,297 HSC donations, 63 donors (1.0%) were reported by the harvest teams to have experienced eSAEs. SAEs were de\\x{fb01}ned as follows: death, events dangerous to life, prolongation of hospitalization, permanent failure, disease or abnormality inherited to offspring and other important medical events. The details of eSAEs were pain (8), infection (8), allergy (6), blood access related (5), neuropathy (4), thrombocytopenia (4), liver dysfunction (2), gout (2), tetany (2), epidural hematoma (2), pulmonary embolism (1), and others (19). None died due to eSAEs and 81 percent of donors recovered from eSAEs in an average of 17 days. In comparison with reference (18 to 30 years) the relative risk of eSAEs was 0.74 for donors aged 31-35 years, 0.37 for 36-40 years, 0.62 for 41-45 years, 1.04 for 46-50 years, 0.77 for 51-55 years, 1.27 for 56-60 years, and 2.66 for 61-65 years. Those aged 61-65 years only had significantly elevated risk of eSAE by univariate analysis (P = 0.02). The incidence of eSAE in each age group are shown in the Table. Univariate logistic regression analysis also showed female sex (1.3% vs 0.7%, 95% CI 1.16-3.55, P = 0.01) and current health conditions (1.9% vs 0.9%, 95% CI 0.99-4.12, P = 0.04) were risk factors affecting eSAEs other than age. Donation type (bone marrow or peripheral blood), laboratory abnormality at health screening and JSHCT donor insurance eligibility criteria did not affect the eSAEs. Multivariate analysis revealed that age category of 61-65 years (Table) and female sex (OR 2.03, 95% CI 1.21-3.43, P = 0.01) were independent predictive factors.[Conclusion] The safety of elderly family HSC donors was significantly inferior to younger donors. Elderly family donors above age 61 should be selected carefully. These findings are useful for informed consent at donations of elderly family donors and consideration the upper limit of age of unrelated volunteer donors.Table 1Relative risk of eSAE adjusted by sexAdjustedNincidenceOR95% CIP-valueTotal1.0%18-30 years16/14931.1%31-35 years6/7580.8%0.750.29-1.910.5436-40 years3/7560.4%0.380.11-1.300.1241-45 years5/7450.7%0.620.23-1.710.3646-50 years8/7201.1%1.040.44-2.440.9351-55 years6/7220.8%0.770.30-1.980.5956-60 years10/7391.4%1.260.57-2.790.5761-65 years9/3212.8%2.661.16-6.060.0266 years -0/430.0%--- DisclosuresNo relevant conflicts of interest to declare.

Two Cases of Successful Autologous Hematopoietic Stem Cell Harvest after Treatment with Brentuximab Vedotin

Two Cases of Successful Autologous Hematopoietic Stem Cell Harvest after Treatment with Brentuximab Vedotin

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

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

Sequential R-CHOP and R-FM Chemotherapy Followed By Autologous Stem Cell Transplantation Results In High Rates Of Long Term Remission In Advanced Follicular Lymphoma

IntroductionAutologous stem cell transplantation (ASCT) is a potentially curative treatment option for relapsed Follicular Lymphoma (FL) patients, but to date available data do not support the use of ASCT as first line consolidation, given the lack of overall survival (OS) advantage compared to standard therapy. R-CHOP (Rituximab-Cyclophosphamide, Vincristine, Doxorubicin, Prednisone) and R-FM (Rituximab, Fludarabine, Mitoxantrone), have comparable efficacy and are widely used as first and second line combinations. The best way to sequence the available therapies in FL is still undefined. Here we show the long term results of a phase II trial of sequential chemotherapy alternating CHOP and FM plus Rituximab followed by ASCT in patients with stage III-IV and/or bulky FL either at disease onset or first relapse, conducted in our Institution from 2002 to 2008. MethodsPatients at diagnosis or first relapse were treated in sequence with R-CHOP for 4 cycles, Endoxan 7g/m2 followed by hematopoietic stem cell harvest, R-FM for 4 cycles and ASCT. The ASCT conditioning schedule was BEAM (BCNU, ARA-C, Etoposide, Melphalan) in all cases. Results24 patients were enrolled, 12 pts were male. Median age was 44 years. One patient did not undergo ASCT for insufficient left ventricular ejection fraction and was excluded from the analysis. 13 patients were treated upfront whereas 10 patients at first relapse. After a median follow-up of 10 years, progression free survival (PFS) and OS in the whole study cohort were respectively 65% and 87%, with a complete response (CR) rate after the completion of sequential treatment of 100%. PFS and OS for patients treated at disease relapse were 60 and 70% (4 relapses, 3 deaths). Remarkably PFS and OS for the 13 patients treated upfront was 70% and 100% (4 relapses). To date no secondary malignancies were observed. ConclusionsSequential treatment alternating standard R-CHOP and R-FM followed by ASCT results in impressive long term PFS and OS rates, both in first line and at relapse. These data represent the proof of principle of a sequential therapy containing alternating alkylating agents and purine analogs followed by ASCT in FL. Disclosures:No relevant conflicts of interest to declare.

Collection of Hematopoietic Stem Cells after Previous Radioimmunotherapy is Feasible and Does Not Impair Engraftment after Autologous Stem Cell Transplantation in Follicular Lymphoma

Major concerns about radioimmunotherapy (RIT) administration early in the course of follicular lymphoma (FL) are long-term toxicity and the theoretical impairment of hematopoietic stem cell (HSC) harvest, but few data are available about mobilization rates after RIT. This study evaluates the impact of prior therapy with RIT (yttrium-90 ibritumomab tiuxetan) and different chemotherapy regimens in all FL patients (N = 103) attempting HSC mobilization at our institution over the last 7 years. Sixty-nine patients received R-CHOP (rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone) or CHOP-like regimens, 21 patients received R-FM (rituximab-fludarabine-mitoxantrone), and 13 patients received RIT before HSC mobilization. Median CD34+ cell yield at first mobilization was 7.2 × 10(6)/kg in the R-CHOP group versus 4.3 in the R-FM group versus 1.7 in the RIT group (P = .02 R-CHOP versus R-FM; P < .0001 R-CHOP versus RIT; P < .02 R-FM versus RIT). Although 8 of 13 patients initially failed to collect enough HSC after RIT, a second and/or salvage harvest was successfully performed in 7 patients, with 10 of 13 patients (77%) finally undergoing autologous stem cell transplantation (ASCT). No differences in engraftment kinetics were observed between the three groups (R-CHOP versus R-FM versus RIT). Although mobilization was significantly impaired in patients previously treated with RIT, a salvage HSC harvest and ASCT after RIT were safe and feasible in most patients.

Plerixafor Single Agent for Autologous Stem Cells Mobilization and Collection in Adult Thalassemic Patients: Towards the Assessment of the Suitable Hematopoietic Stem Cell Source for Gene Therapy of Beta-Thalassemia.

AbstractAbstract 586Gene therapy of inherited blood diseases requires harvest of hematopoietic stem cells (HSCs) from patients and autologous transplantation of genetically modified cells. In order to achieve correction of the disease, high number of HSCs and previous conditioning of the host bone marrow (BM) are necessary. In the clinical application of gene therapy for thalassemic patients the choice of the HSC source is a crucial issue. On one side, the minimal target dose poses a challenge for the use of steady state BM since reinfusion of high numbers of beta globin gene modified CD34+ cells is probably necessary to gain sufficient correction of the genetic defect in order to achieve transfusion independency; on the other side, the disease related features and complications of thalassemic patients (i.e. splenomegaly and thrombophilia) dictate caution in the use of G-CSF as mobilizing agent.In April 2011 a clinical protocol exploring the use of Plerixafor (AMD3100) as single agent was started (“Plerixafor mobilized stem cells as source for gene therapy of beta-thalassemia”, acronym AMD-THAL, EudraCT2011-000973-30). Aims of the trial were to explore the ability of Plerixafor in inducing safe and effective stem cells mobilization in adult patients affected by beta-thalassemia, to characterize stem/progenitor cells mobilized from the BM and peripheral blood of treated subjects and to achieve gene transfer efficiency of mobilized CD34+ cells at a level comparable to that obtained using steady state BM.Four patients (01, 02, 03 and 04) were enrolled and already mobilized to date (August 2012). All patients are affected by transfusion dependent beta-thalassemia and aged 28 (01), 41 (02), 39 (03), 33 (04). Two are splenectomized (02 and 03); all subjects are regularly iron chelated with adequate organ function. Administration of Plerixafor subcutaneously as single agent and at the single dose of 0.24 mg/kg resulted in mobilization of CD34+ cells/mcl with a peak of 78 cells at 9 hrs (01), 70 cells at 7 hrs (02) and 69 cells at 8 hrs (03); suboptimal mobilization was observed in patient 04 (peak 18 at 8 hrs). Patient 03 received a second dose at 0.40 mg/kg 24 hrs after the first dose and underwent a second leucoapheretic procedure. Harvest by leukoapharesis resulted in procurement of the following CD34+ cells/kg: 1.84 × 106 (01) and 4.43 × 106 (02) with a unique leukoapheretic procedure, and 3.57 × 106 (03) with two leukoapheresis. No apheresis was performed for patient 04 because the minimum target of 20 CD34+ cells/mcl in peripheral blood was not reached. CD34+ cells selection through Clinimacs Miltenyi resulted in the following yield: 1.2 × 106 CD34+ cells/Kg, 65% recovery (01), 2.66 × 106 CD34+ cells/Kg, 60% recovery (02), 1.78 × 106 CD34+ cells/Kg, 50% recovery (03). No severe adverse event occurred. Recorded side effects were: grade 3 hypotension related to the apheretic procedure (01), mild grade 1 facial disestesia (02 and 04) and hyperleukocytosis (02: WBC from 13.6 to 42.6 × 103/mcl). In addition, steady state and Plerixafor primed BM aspirates were performed to analyze any modification in CD34+ concentration in the BM following Plerixafor administration. In fact, Plerixafor administration resulted in enrichment of CD34+ cells concentration in the BM.Purified CD34+ cells from leukoapheresis of the 4 treated patients were analyzed for their biological and functional properties, subpopulations composition and expression profile. In vivo reconstitution potential and lymphomyeloid differentiation of CD34+ cells were tested following transplantation in NSG mice. Experiments are ongoing but preliminary results indicate that cells mobilized by Plerixafor have a primitive phenotype with a high reconstitution potential and are efficiently transduced with a lentiviral based vector, named GLOBE, encoding for the human beta-globin (Roselli et al., 2010), thus being a suitable source of target cells for gene therapy. Disclosures:No relevant conflicts of interest to declare.

Mobilization and Harvesting of Peripheral Blood Stem Cells in Pediatric Patients With Solid Tumors

Survival of patients with high-risk pediatric solid tumors has improved with the introduction of a high-dose chemotherapy regimen and autologous stem cell rescue. Here, we present our data regarding the evaluation of the efficacy and safety of hematopoietic stem cell mobilization and harvesting in children with solid tumors. From November 2002 to March 2010, 85 children underwent autologous peripheral blood stem cell collection; 35 (41.1%) of them weighed less than 20 kg and were diagnosed with neuroblastoma, Wilms' tumor, medulloblastoma, yolk sac sarcoma, or non-Hodgkin's lymphoma. The mobilization regimens included disease-specific chemotherapy plus granulocyte colony-stimulating factor in most of the patients. The median age and weight at the time of apheresis was 36 months and 13.5 kg, respectively. Large-volume leukapheresis was performed with the aim of reducing the psychological and financial impact of leukapheresis by reducing the number of procedures while collecting a large number of cells. The median number of mobilization and leukapheresis procedures per case was one. The pre-apheresis CD34+ cell count ranged from 2 to 845 µL, with a median of 24 µL. A median of four patient blood volumes was processed per procedure, lasting 279 min (range, 113-420 min). A radial catheter was used for harvesting in 35 procedures (71.4%). The median yield of CD34+ cells was 6.6×10(6) /kg per patient. The targeted dose of 5×10(6) /kg CD34+ cells was realized in 80% of patients. The tolerance of peripheral blood stem cell collection in our patients was good. In conclusion, the collection of peripheral blood stem cells is an effective and safe procedure, even when conducted on the youngest children.