Treatment of adult ALL patients with third-generation CD19-directed CAR T cells: results of a pivotal trial.

BACKGROUND: Third-generation chimeric antigen receptor (CAR)-engineered T cells (CARTs) might improve clinical outcome of patients with B cell malignancies. This is the first report on a third-generation CART dose-escalating, phase-1/2 investigator-initiated trial treating adult patients with refractory and/or relapsed (r/r) acute lymphoblastic leukemia (ALL). METHODS: Thirteen patients were treated with escalating doses of CD19-directed CARTs between 1 × 106 and 50 × 106 CARTs/m2. Leukapheresis, manufacturing and administration of CARTs were performed in-house. RESULTS: For all patients, CART manufacturing was feasible. None of the patients developed any grade of Immune effector cell-associated neurotoxicity syndrome (ICANS) or a higher-grade (≥ grade III) catokine release syndrome (CRS). CART expansion and long-term CART persistence were evident in the peripheral blood (PB) of evaluable patients. At end of study on day 90 after CARTs, ten patients were evaluable for response: Eight patients (80%) achieved a complete remission (CR), including five patients (50%) with minimal residual disease (MRD)-negative CR. Response and outcome were associated with the administered CART dose. At 1-year follow-up, median overall survival was not reached and progression-free survival (PFS) was 38%. Median PFS was reached on day 120. Lack of CD39-expression on memory-like T cells was more frequent in CART products of responders when compared to CART products of non-responders. After CART administration, higher CD8 + and γδ-T cell frequencies, a physiological pattern of immune cells and lower monocyte counts in the PB were associated with response. CONCLUSION: In conclusion, third-generation CARTs were associated with promising clinical efficacy and remarkably low procedure-specific toxicity, thereby opening new therapeutic perspectives for patients with r/r ALL. Trial registration This trial was registered at www. CLINICALTRIALS: gov as NCT03676504.

Clonal hematopoiesis with DNMT3A and PPM1D mutations impairs regeneration in autologous stem cell transplant recipients.

Clonal hematopoiesis (CH) is an age-related condition driven by stem and progenitor cells harboring recurrent mutations linked to myeloid neoplasms. Currently, potential effects on hematopoiesis, stem cell function and regenerative potential under stress conditions are unknown. We performed targeted DNA sequencing of 457 hematopoietic stem cell grafts collected for autologous stem cell transplantation (ASCT) in myeloma patients and correlated our findings with high-dimensional longitudinal clinical and laboratory data (26,510 data points for blood cell counts/serum values in 25 days around transplantation). We detected CHrelated mutations in 152 patients (33.3%). Since many patients (n=54) harbored multiple CH mutations in one or more genes, we applied a non-negative matrix factorization (NMF) clustering algorithm to identify genes that are commonly co-mutated in an unbiased approach. Patients with CH were assigned to one of three clusters (C1-C3) and compared to patients without CH (C0) in a gene specific manner. To study the dynamics of blood cell regeneration following ASCT, we developed a time-dependent linear mixed effect model to validate differences in blood cell count trajectories amongst different clusters. The results demonstrated that C2, composed of patients with DNMT3A and PPM1D single and co-mutated CH, correlated with reduced stem cell yields and delayed platelet count recovery following ASCT. Also, the benefit of maintenance therapy was particularly strong in C2 patients. Taken together, these data indicate an impaired regenerative potential of hematopoietic stem cell grafts harboring CH with DNMT3A and PPM1D mutations.

Peroxisomal Fatty Acid Oxidation and Glycolysis Are Triggered in Mouse Models of Lesional Atopic Dermatitis.

Alterations of the lipid profile of the stratum corneum have an important role in the pathogenesis of atopic dermatitis (AD) because they contribute to epidermal barrier impairment. However, they have not previously been envisioned as a cellular response to altered metabolic requirements in AD epidermis. In this study, we report that the lipid composition in the epidermis of flaky tail, that is, ft/ft mice mimics that of human lesional AD (ADL) epidermis, both showing a shift toward shorter lipid species. The amounts of C24 and C26 free fatty acids and C24 and C26 ceramides-oxidized exclusively in peroxisomes-were reduced in the epidermis of ft/ft mice despite increased lipid synthesis, similar to that seen in human ADL edpidermis. Increased ACOX1 protein and activity in granular keratinocytes of ft/ft epidermis, altered lipid profile in human epidermal equivalents overexpressing ACOX1, and increased ACOX1 immunostaining in skin biopsies from patients with ADL suggest that peroxisomal ß-oxidation significantly contributes to lipid signature in ADL epidermis. Moreover, we show that increased anaerobic glycolysis in ft/ft mouse epidermis is essential for keratinocyte proliferation and adenosine triphosphate synthesis but does not contribute to local inflammation. Thus, this work evidenced a metabolic shift toward enhanced peroxisomal ß-oxidation and anaerobic glycolysis in ADL epidermis.

Local Radiation Therapy Before and During Induction Delays Stem Cell Mobilization and Collection in Multiple Myeloma Patients.

In multiple myeloma, local radiation therapy (RT) of osseous lesions before peripheral blood stem cell (PBSC) mobilization is assumed to impair the PBSC mobilization and collection. However, the results of previously published studies are inconsistent and do not evaluate detailed metrics of RT and PBSC outcome parameters. In total, 352 patients undergoing PBSC mobilizations and RT in first-line treatment were evaluated. Patients were grouped into RT (n = 283) and no RT (n = 69) before PBSC mobilization. Except for the International Staging System score, both groups were homogeneous regarding the first diagnosis characteristics, first-line treatments, and response parameters. RT metrics (RT yes versus no, volume of irradiated hematopoietic bone marrow [BM], biologically equivalent doses in 2 Gy fractions [EQD2]) were analyzed for the following PBSC outcome parameters: achievement of the PBSC collection goal, CD34+ cell collection yield, duration of the mobilization phase, and number of leukapheresis (LP) sessions to reach the collection goal. No statistically significant differences in the percentage of collection failures to reach at least 3 sufficient PBSC transplants were identified comparing patients with (n = 32 [11%]) and without RT (n = 4 [6%]) before PBSC mobilization (P = .265). However, patients with RT before PBSC mobilization showed a significant prolongation of the PBSC mobilization (median 1 day, P =.026) and required a higher number of LP sessions to reach the collection goal (median 1 LP, P < .001) compared with patients who received RT after PBSC mobilization. Moreover, patients with RT before PBSC mobilization reached a significantly lower CD34+ cell collection result (mean 8.94 versus 9.81 × 106/kg body weight [bw], P = .002). No correlation was identified between the overall CD34+ cell yield and the volume of irradiated hematopoietic BM or EQD2, respectively. In the RT before PBSC mobilization group, patients who required more than 1 LP session to reach the PBSC collection goal after RT had a significantly higher percentage of radiated hematopoietic BM compared to those who required only 1 LP session (mean 9.7% versus 7.2%, P = .002). Overall, our study indicates a negative impact of RT on PBSC mobilization and collection. Apart from emergency settings, it might be beneficial to postpone RT to a post-PBSC collection time point. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Cryostorage to What End? - Autologous Stem Cell Products in Burkitt Lymphoma, Acute Lymphoblastic Leukemia, Acute Myeloid Leukemia, and Myeloproliferative Neoplasm Patients.

INTRODUCTION: Recently, we identified a huge discrepancy between the collection practice and the actual utilization of cryopreserved peripheral blood stem cells (PBSCs) for high-dose chemotherapy (HDCT) and autologous blood stem cell transplantation (ABSCT). Specifically, patients with Burkitt lymphoma, acute leukemia, and myeloproliferative neoplasms (MPN) were frequently not referred for ABSCT after successful PBSC collection. OBJECTIVE: The aim of this study was to identify variables that are associated with the non-utilization of PBSC grafts. METHODS: We retrospectively analyzed the collection, storage, and disposal of PBSC grafts in Burkitt lymphoma (n = 18), acute lymphoblastic leukemia (ALL, n = 22), MPN (n = 18), and acute myeloid leukemia (AML, n = 71) patients. Patients who underwent autologous PBSC collection at 2 collection and transplantation centers between 2001 and 2012 were included and followed up until 2016. RESULTS: None of the Burkitt lymphoma patients were referred for ABSCT. Only in 1 (6%) patient, the graft was discarded after the patient's death. In all other patients (n = 17, 94%), the grafts were stored independently of the patient's status (death, n = 4, 22%; no follow-up, n = 6, 33%; no indication for ABSCT given, n = 7, 39%). In ALL patients, 4 (18%) patients underwent ABSCT after a median follow-up of 74 (1-182) months. In the remaining patients, PBSC grafts were either discarded (8 patients, 36%) or stored until the reference date (10 patients, 45%). Seven of 18 MPN patients (39%) underwent ABSCT. ABSCT was performed in 24 (34%) AML patients. In 20 (28%) patients who were not referred to ABSCT, an allogeneic transplantation (TPL) was performed. Fifteen (21%) patients received palliative care or deceased, and their grafts were discarded in all but 1 patient. Additional grafts were discarded in 21 (31%) patients and stored in 9 (13%) patients who underwent ABSCT or allogeneic TPL (n = 44). CONCLUSIONS: As the role and efficacy of autologous HDCT/ABSCT are not established in the analyzed entities, the indication for PBSC collection should be reanalyzed in regular intervals. Moreover, PBSC grafts from patients who have deceased, have insufficient grafts, or have already undergone an allogeneic TPL should be considered for disposal or (if applicable) for research use, to economize storage costs on a rational basis.

CAR T cells or allogeneic transplantation as standard of care for advanced large B-cell lymphoma: an intent-to-treat comparison.

CD19-directed chimeric antigen receptor (CAR) T-cell treatment has evolved as standard of care (SOC) for multiply relapsed/refractory (R/R) large B-cell lymphoma (LBCL). However, its potential benefit over allogeneic hematopoietic cell transplantation (alloHCT) remains unclear. We compared outcomes with both types of cellular immunotherapy (CI) by intention to treat (ITT). Eligble were all patients with R/R LBCL and institutional tumor board decision recommending SOC CAR T-cell treatment between July 2018 and February 2020, or alloHCT between January 2004 and February 2020. Primary end point was overall survival (OS) from indication. Altogether, 41 and 60 patients for whom CAR T cells and alloHCT were intended, respectively, were included. In both cohorts, virtually all patients had active disease at indication. CI was recommended as part of second-line therapy for 21 alloHCT patients but no CAR T-cell patients. Median OS from indication was 475 days with CAR T cells vs 285 days with alloHCT (P = .88) and 222 days for 39 patients for whom alloHCT beyond second line was recommended (P = .08). Of CAR T-cell and alloHCT patients, 73% and 65%, respectively, proceeded to CI. After CI, 12-month estimates for nonrelapse mortality, relapse incidence, progression-free survival, and OS for CAR T cells vs alloHCT were 3% vs 21% (P = .04), 59% vs 44% (P = .12), 39% vs 33% (P = .97), and 68% vs 54% (P = .32), respectively. In conclusion, CAR T-cell outcomes were not inferior to alloHCT outcomes, whether measured by ITT or from CI administration, supporting strategies preferring CAR T cells over alloHCT as first CI for multiply R/R LBCL.

Storage, Utilization, and Disposal of Hematopoietic Stem Cell Products in Patients with Multiple Myeloma.

High-dose chemotherapy (HD-CHT) and autologous blood stem cell transplantation (ABSCT) represent the standard of care in multiple myeloma (MM) for transplantation-eligible patients. Up to 3 HD-CHT/ABSCT treatments may be administered during the course of disease, including during late-onset relapse. Transplantation centers routinely collect more than 1 peripheral blood stem cell (PBSC) graft; however, subsequent HD-CHT/ABSCT treatments are often not performed, for various reasons. Currently, little is known about the actual utilization rate of stored PBSCs. The collection, storage, and disposal of PBSC products was analyzed in a large cohort of patients with MM (n = 1114) over a 12-year period with a minimum follow-up of 6 years. The final dataset analysis was performed in March 2019, which was set as the reference date. Based on institution-specific charges, the costs for PBSC collection, processing, and storage were estimated. The median number of sufficient PBSC transplantations per patient was 3 (range, 0 to 6), which were stored in a median of 3 (range, 1 to 11) cryopreserved bags (overall, n = 3644). A total of 95% of all patients (n = 1059) underwent at least 1 HD-CHT/ABSCT treatment. However, multiple ABSCTs were performed in 51% of the patients (n2/3 ABSCTs = 538), and only 14% of the patients underwent ABSCT 3 times (n3 ABSCTs = 149). Only a small proportion of collected PBSC bags (5%; n = 109) were used after being stored for longer than 5 years. Overall, 23% of the products (n = 830) were discarded, and 16% (n = 566) were kept in storage until the reference date. From a retrospective standpoint, the collected and discarded (definitively not used) or stored (potentially not used) cryostored PBSCs were associated with considerable costs for long-term cryostorage of approximately €1,600,000. We identified considerable discrepancies between the collection/storage and utilization of PBSCs. This is associated with significant efforts and costs on the one hand; on the other hand, disposal may raise legal and ethical questions. Therefore, we implemented comprehensive guidelines for the systematic reevaluation of stored PBSC grafts at our institution.

Current Challenges in Providing Good Leukapheresis Products for Manufacturing of CAR-T Cells for Patients with Relapsed/Refractory NHL or ALL.

BACKGROUND: T lymphocyte collection through leukapheresis is an essential step for chimeric antigen receptor T (CAR-T) cell therapy. Timing of apheresis is challenging in heavily pretreated patients who suffer from rapid progressive disease and receive T cell impairing medication. METHODS: A total of 75 unstimulated leukaphereses were analyzed including 45 aphereses in patients and 30 in healthy donors. Thereof, 41 adult patients with Non-Hodgkin's lymphoma (85%) or acute lymphoblastic leukemia (15%) underwent leukapheresis for CAR-T cell production. RESULTS: Sufficient lymphocytes were harvested from all patients even from those with low peripheral lymphocyte counts of 0.18/nL. Only four patients required a second leukapheresis session. Leukapheresis products contained a median of 98 × 108 (9 - 341 × 108) total nucleated cells (TNC) with 38 × 108 (4 - 232 × 108) CD3+ T cells. Leukapheresis products from healthy donors as well as from patients in complete remission were characterized by high TNC and CD3+ T lymphocyte counts. CAR-T cell products could be manufactured for all but one patient. CONCLUSIONS: Sufficient yield of lymphocytes for CAR-T cell production is feasible also for patients with low peripheral blood counts. Up to 12-15 L blood volume should be processed in patients with absolute lymphocyte counts ≤ 1.0/nL.

Feasibility and Safety of CD19 Chimeric Antigen Receptor T Cell Treatment for B Cell Lymphoma Relapse after Allogeneic Hematopoietic Stem Cell Transplantation.

Although CD19-directed chimeric antigen receptor (CAR) T cells have been successfully used after a preceding allogeneic stem cell transplant (alloHCT) in patients with acute lymphoblastic leukemia, little is known about the feasibility and outcome of CAR T cell treatment in patients who have been previously allotransplanted for lymphoma. In a single-center retrospective analysis, course and outcome of all allografted patients treated with CD19 CAR constructs for B cell lymphoma between October 2018 and November 2019 were studied. CAR therapy consisted either of a third-generation CAR (HD-CAR-1) or of commercially manufactured axicabtagene ciloleucel (axi-cel; Gilead, Santa Monica, U.S.). Altogether, 10 CAR T cell dosings using recipient leukapheresis products were performed in 8 patients: 4 patients (2 mantle cell lymphoma, 2 chronic lymphocytic leukemia) received 6 dosings with HD-CAR-1 and 4 patients (all with diffuse large B cell lymphoma) received 4 dosings with axi-cel. Overall, 6 of 8 patients (75%) responded. CAR treatment was well tolerated with grade ≥ 3 cytokine release syndrome and neurotoxicity each being observed after 1 of 10 dosings. A single patient had moderate chronic graft-versus-host disease. Of note, 3 of 4 patients who received axi-cel had ongoing grade ≥ 3 cytopenia 3 months postdosing, whereas prolonged cytopenia was not observed in 9 alloHCT-naive patients who received axi-cel during the same time period. In conclusion, CAR T cell treatment from recipient-derived leukapheresis products after a prior alloHCT appears to be feasible, effective, and safe in patients with B cell lymphoma. Protracted cytopenia after axi-cel treatment is a matter of concern and requires further exploration.

Low-dose peripheral blood stem cell graft after high-dose chemotherapy - an evaluation of hematopoietic reconstitution.

BACKGROUND: High-dose (HD) chemotherapy followed by autologous blood stem-cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) patients. However, the collection of sufficient peripheral blood stem cell (PBSC) grafts can be challenging, and the question arises whether reinfusion of low-dose grafts will lead to a hematopoietic recovery. METHODS: The hematopoietic recovery of 148 MM patients who underwent HD melphalan chemotherapy and received PBSC transplants with varying CD34+ cells doses (3-4 × 106 [n = 86], 2-2.5 × 106 [n = 53], < 2 × 106 [n = 9] per kg body weight [bw]) was analyzed in this retrospective single-center study. RESULTS: All patients reached hematopoietic reconstitution, even those who received < 2 × 106 CD34+ cells/kg bw. 62 (42%) patients received granulocyte-colony-stimulating factor (G-CSF). The median duration to leukocyte recovery ≥1.0 × 109/L was 12 days in every group. The median duration to platelet recovery ≥20 × 109/L was 11, 13 and 13 days, respectively. In the multivariate analysis, a low number of reinfused CD34+ cells was associated with prolonged time until leukocyte reconstitution (p = 0.010, HR 0.607) and platelet recovery (p < 0.001, HR 0.438). G-CSF support significantly accelerated leukocyte (p < 0.001, HR 16.742) but not platelet reconstitution. CONCLUSION: In conclusion, reinfusion of low- and even very-low-dose PBSC grafts leads to sufficient hematopoietic reconstitution. No severe adverse events were observed during or after HD chemotherapy and ASCT in the analyzed cohort. While the impact of CD34+ cell dose is marginal, G-CSF significantly accelerates the leukocyte recovery.

A Freezing Protocol for Hematopoietic Stem Cells.

Especially in the field of autologous transplantation, it has been found necessary to develop methods that ensure long-term storage with maintenance of functionality of the cells to bridge the therapy-related temporal separation of collection and application.Based on the experiences of more than 40 years, some practical considerations, especially regarding the cell concentration, final volume, and possibly other exogenous substances, should be considered when establishing a protocol for the routine cryopreservation of peripheral blood stem cells. In the following chapter, we describe a freezing protocol for cryopreservation of peripheral blood stem cells which was used and optimized over the past 8 years and was applied to the cryopreservation of more than 2000 peripheral stem cell transplants.

Collection, Cryostorage, Transplantation, and Disposal of Hematopoietic Stem Cell Products.

Many transplantation centers routinely collect 1 or more autologous peripheral blood stem cell (PBSC) grafts in patients with hemato-oncologic and autoimmune disorders. However, subsequent high-dose chemotherapy and autologous blood stem cell transplantation (ABSCT) are often not performed, for various reasons. Currently, little is known about the actual utilization rate of stored PBSCs. We retrospectively analyzed the collection, storage, and disposal practices of PBSC products from a large cohort of patients (n = 1020) with hematologic, oncologic, and autoimmune disorders at our institution over a 12-year period. Patients with multiple myeloma were excluded. Based on our institution-specific charges, we estimated the costs for PBSC collection/processing and storage. The median number of sufficient PBSC collections per patient in the whole cohort was 2 (range, 1 to 6). We could demonstrate that only 67% of all patients who had collected sufficient PBSCs for transplantation actually underwent ABSCT, and only a small minority of all patients (4%) underwent multiple ABSCTs. The actual use of the stored PBSC grafts varied among disease entities from >80% to 0%. From a retrospective standpoint, the collected and discarded (definitively not used) or stored (potentially not used) cryostored PBSCs were associated with considerable costs of collection, cryopreservation, and long-term cryostorage. Although keeping open the therapeutic option for future transplantations may be important, there is currently a huge discrepancy between collection/storage practices and actual utilization of the cryopreserved PBSCs, at a considerable cost and strain on patients. Our study provides a rationale for reevaluating the present standards.

Platelet Count before Peripheral Blood Stem Cell Mobilization Is Associated with the Need for Plerixafor But Not with the Collection Result.

BACKGROUND: A low platelet count before mobilization has recurrently been identified as risk factor for poor mobilization. METHODS: To determine the relevance of this finding for peripheral blood stem cell (PBSC) mobilization, including pre-emptive or rescue plerixafor in the case of poor mobilization, we retrospectively analyzed all patients undergoing PBSC collection at our institution between January 2014 and December 2015 (n = 380). RESULTS: In total, 99% of the patients (377/380) successfully collected a minimum of 2 × 106 CD34+ cells/kg body weight sufficient for a single transplant. Rescue or pre-emptive plerixafor was administered to 11% of the patients (42/380). No correlations between the platelet count before mobilization and the number of peripheral blood CD34+ cells or the CD34+ cell collection result were detected in the entire population or the subgroups according to diagnosis (newly diagnosed multiple myeloma, relapsed multiple myeloma, lymphoma, amyloid light-chain amyloidosis, sarcoma, or germ cell tumor). However, patients requiring pre-emptive or rescue plerixafor had a significantly lower platelet count before mobilization (217/nl vs. 245/nl; p = 0.004). CONCLUSION: With the current state of the art PBSC mobilization strategies, the platelet count before mobilization was not associated with the CD34+ cell collection result but was associated with the need for pre-emptive or rescue application of plerixafor.

Comparison of biosimilar filgrastim, originator filgrastim, and lenograstim for autologous stem cell mobilization in patients with multiple myeloma.

BACKGROUND: Granulocyte-colony-stimulating factor (G-CSF) originators such as filgrastim (Neupogen) and lenograstim (Granocyte) are widely used for peripheral blood stem cell (PBSC) mobilization. In recent years, biosimilar agents have been approved for the same indications. The aim of this retrospective study was to compare the mobilization efficiency of the three G-CSF variants originator filgrastim, lenograstim, and the biosimilar Filgrastim Hexal in a homogeneous group of multiple myeloma (MM) patients in first-line therapy. STUDY DESIGN AND METHODS: Overall mobilization data of 250 patients with MM were included. Of these patients, 74 (30%), 131 (52%), and 45 (18%) were mobilized with originator filgrastim, biosimilar Filgrastim Hexal, or lenograstim, respectively, at a dose of 5 to 10 µg/kg body weight subcutaneously starting from Day 5 after chemomobilization with CAD (cyclophosphamide, doxorubicin, dexamethasone) until completion of PBSC collection. RESULTS: All but one patient reached the collection goal of a minimum of at least 2 × 106 CD34+ cells/kg body weight during a median of one (range, one to three) leukapheresis session. No significant differences in CD34+ mobilization and collection yields between the filgrastim-mobilized (median, 10.5; range, 2.7-40.4), Filgrastim Hexal-mobilized (median, 9.9; range, 0.2-26.0), and lenograstim-mobilized (median, 10.7; range, 3.1-27.9 CD34+ cells × 106 /kg body weight) patients were observed. CONCLUSION: Concerning the clinically relevant efficiencies of PBSC mobilization and in terms of reaching the individual collection target, this retrospective study did not detect any significant differences between the three G-CSF variants in the analyzed patient cohort.

Comparison between intermittent and continuous spectra optia leukapheresis systems for autologous peripheral blood stem cell collection.

Terumo BCT recently introduced a new system for mononuclear cell (MNC) collection that uses a Spectra Optia apheresis machine equipped with a redesigned disposable kit and software program (version 11.2). It allows for the continuous collection of MNCs, unlike the original Spectra Optia system (version 7.2), which included a chamber for two-step cell separation. The aim of this study was to compare the two apheresis systems in regard to specific performance parameters. A retrospective data analysis of 150 patients who had undergone peripheral blood stem cell collection between March of 2014 and May of 2015 at our institution was performed. For the matched comparison, patients were divided into two groups by diagnosis and by previous forms of therapy received: a homogeneous group of patients with multiple myeloma (MM) that had received first line therapy ("MM" group, n = 88) and a heterogeneous group that included all of the other patients ("other" group, n = 62). No significant differences in CD34+ collection yields between both collection regimens were found (pMM = 0.19, pother = 0.74) in either group. Moreover, similar performance ratios (collected/predicted CD34+ cell number in %) were observed (pMM = 0.89, pother = 0.1). No relevant variations in platelet or hemoglobin loss were found between the two systems. We conclude that the new continuous Spectra Optia MNC system is equally efficient in collecting CD34+ cells and can be used without sacrificing collection efficiency levels when treating a broad variety of autologous patients. J. Clin. Apheresis 32:27-34, 2017. © 2016 Wiley Periodicals, Inc.

Storage Duration of Autologous Stem Cell Preparations Has No Impact on Hematopoietic Recovery after Transplantation.

Peripheral blood stem cells (PBSCs) are widely used for autologous blood stem cell transplantation (ABSCT). These cells must be stored for months or even years, usually at temperatures ≤-140°C, until their use. Although several in vitro studies on CD34+ viability and clonogenic assays of PBSCs after long-term storage have been reported, only a few publications have investigated the influence of long-term storage on in vivo hematopoietic reconstitution. In this study, we retrospectively analyzed hematopoietic recovery after storage of PBSCs via controlled-rate freezing (CRF) and cryostorage in 10% DMSO at ≤-140°C in 105 patients with multiple myeloma who received high-dose melphalan before ABSCT. Three groups of PBSC transplantation (n = 247) were delineated based on the storage period: short-term (≤12 months, n = 143), medium-term (>12 and ≤60 months, n = 75), and long-term storage (>60 months, n = 29). A neutrophil increase of ≥.5 × 109/L in medium-term or long-term PBSC cryopreservation groups was observed at day 14 after ABSCT; this increase was comparable to patients who received briefly stored PBSCs (day 15). No negative effect of PBSC storage duration was observed on leucocyte or neutrophil reconstitution. Platelet reconstitutions of ≥20 × 109/L and 50 × 109/L were observed after median times of 10 to 11 and 13 to 14 days after ABSCT, respectively. No influence of PBSC storage duration on platelet recovery of ≥20 × 109/L and ≥50 × 109/L was observed in the 3 storage groups (P = .07, P = .32). The number of previous ABSCTs also had no significant impact upon hematopoietic reconstitution. In conclusion, these results indicate that long-term cryopreservation of PBSC products at vapor nitrogen temperature after CRF does not have a negative effect on hematopoietic recovery even after prolonged storage.

Bone Marrow Harvesting of Allogeneic Donors in an Outpatient Setting: A Single-Center Experience.

The aim of this retrospective study was to assess the safety and efficacy of bone marrow (BM) harvesting of allogeneic donors in an outpatient setting. Data of 226 related and unrelated donors who underwent BM harvest under general anesthesia at our institution from 2002 to 2014 were analyzed. Sixteen patients were a priori planned for admission for social reasons and 210 patients underwent BM harvesting with the intention to perform this procedure on an outpatient basis. To identify factors that predispose for hospital admission, we retrospectively analyzed donor characteristics and collection parameters. Outpatient treatment was performed in 178 of 210 donors (85%), whereas 32 donors (15%) required admission for clinical reasons (mainly clinically relevant anemia and circulatory problems). These individuals were not significantly different in sex distribution, age, donor's body weight, and the proportion of related donors from those who were not admitted. However, we found a significantly higher collection volume per kilogram donor's body weight in inpatients compared with volume for outpatients (16 versus 13 mL/kg body weight, P < .001). Severe adverse events or deaths occurred neither in the inpatient nor in the outpatient setting. Our study demonstrated that BM harvest in an outpatient setting is safe and feasible for the majority of allogeneic donors. A high volume of BM represented a major risk factor for inpatient admission.

Low-dose cyclophosphamide effectively mobilizes peripheral blood stem cells in patients with autoimmune disease.

For patients with severe and refractory autoimmune diseases, high-dose chemotherapy and autologous hematopoietic stem cell transplantation has been established as a considerable therapeutic option in recent years. In this retrospective single-center analysis, we assessed the feasibility and efficacy of peripheral blood stem cells (PBSC) mobilization and collection in 35 patients with refractory autoimmune disease (AID). The mobilization data of 15 patients with systemic sclerosis (SSc), 11 patients with multiple sclerosis (MS), and 9 patients with other AID were analyzed. Stem cell mobilization with cyclophosphamide chemotherapy 2 × 2 g/m(2) (n = 16) or 1 × 2 g/m(2) (n = 17) and G-CSF followed by PBSC collection was performed between 1999 and 2015. Leukapheresis was performed in 16 inpatients and 19 outpatients. All patients reached their collection goal and no collection failures were observed. The median PBSC collection result was 12.2 (SSc), 8.0 (MS), and 8.2 (other AID) × 10(6) CD34+ cells/kg, respectively. Twenty-five of 35 (71%) patients achieved a sufficient collection with one leukapheresis session, while 6 patients (17%) required two and 4 patients (11%) required three or more leukapheresis sessions. No correlation of the collected PBSC number was observed regarding age, body weight, diagnosis, disease duration, skin sclerosis, or previous cyclophosphamide. Mobilization chemotherapy with cyclophosphamide 2 × 2 g/m(2) and 1 × 2 g/m(2) delivered comparable mobilization results with leukapheresis on day 13 or 14. In summary, we demonstrate that PBSC collection is safe and feasible in patients with AID. Mobilization chemotherapy with cyclophosphamide 1 × 2 g/m(2) and 2 × 2 g/m(2) is equally effective in those patients.

Standardization of Good Manufacturing Practice-compliant production of bone marrow-derived human mesenchymal stromal cells for immunotherapeutic applications.

BACKGROUND AIMS: Human mesenchymal stem or stromal cells (MSCs) represent a potential resource not only for regenerative medicine but also for immunomodulatory cell therapies. The application of different MSC culture protocols has significantly hampered the comparability of experimental and clinical data from different laboratories and has posed a major obstacle for multicenter clinical trials. Manufacturing of cell products for clinical application in the European Community must be conducted in compliance with Good Manufacturing Practice and requires a manufacturing license. In Germany, the Paul-Ehrlich-Institut as the Federal Authority for Vaccines and Biomedicines is critically involved in the approval process. METHODS: This report summarizes a consensus meeting between researchers, clinicians and regulatory experts on standard quality requirements for MSC production. RESULTS: The strategy for quality control testing depends on the product's cell composition, the manufacturing process and the indication and target patient population. Important quality criteria in this sense are, among others, the immunophenotype of the cells, composition of the culture medium and the risk for malignant transformation, as well as aging and the immunosuppressive potential of the manufactured MSCs. CONCLUSIONS: This position paper intends to provide relevant information to interested parties regarding these criteria to foster the development of scientifically valid and harmonized quality standards and to support approval of MSC-based investigational medicinal products.