Time Of Stem Cell Transplantation Research Articles

High-Dose Chemotherapy and Autologous or Allogeneic Transplantation in Aggressive B-Cell Lymphoma-Is There Still a Role?

Novel therapies such as CAR-T, BTK inhibitors and PD-1 inhibitors have changed the management of aggressive B-cell lymphomas. Nonetheless, these novel therapies have their own risk of late toxicities including second malignancies. They also create a subgroup of patients with relapse, treatment failure, or indefinite maintenance. We discuss the current role of autologous and allogeneic stem cell transplantation in this context. In patients with recurrent diffuse large B-cell lymphoma, CAR-T cell treatment has largely replaced autologous transplant. Autologous transplant should be considered in patients with late relapses and in selected patients with T-cell-rich B-cell lymphoma, where CAR-T cell therapy may be less effective. It also remains the treatment of choice for consolidation of patients with primary CNS lymphoma. In mantle cell lymphoma, intensive chemotherapy combined with BTK inhibitors and rituximab results in excellent outcomes, and the role of autologous transplantation is declining. In Hodgkin's lymphoma, autologous transplant consolidation remains the standard of care for patients who failed initial chemotherapy. Allogeneic transplantation has lower relapse rates but more complications and higher non-relapse mortality than autologous transplantation. It is usually reserved for patients who fail autologous transplantation or in whom autologous stem cells cannot be collected. It may also have an important role in patients who fail CAR-T therapies. The increasing complexity of care and evolving sequencing of therapies for patients with aggressive B-cell lymphomas only emphasizes the importance of appropriate patient selection and optimal timing of stem cell transplantation.

Impact of JAK2 allele burden on MF outcome in the era of ruxolitinib.

6514 Background: Myelodepleted myelofibrosis (MF), characterized bycytopenias, lower JAK2V617F allele burden (JAK2%) and shorter benefit from JAKi ruxolitinib (RUX), has worse survival (OS) compared to myeloproliferative MF. Lower JAK2% and inferior OS is more typical for primary MF (PMF) vs MF from essential thrombocythemia or polycythemia vera (PPV/PET-MF). We sought to investigate the impact of JAK2% (</≥ 50%), cytopenias and the use of RUX in outcome of PMF/PPV-PET-MF patients from our center. Methods: 601 medical charts of JAK2 mutated patients with MF (known JAK2%) were retrospectively reviewed. We divided patients based on the absence (-) or presence (+) of cytopenias (hemoglobin < 10 g/dL or platelets < 100 x10^9/L) and leukocytosis (WBC ≥ 25 x10^9/L) into: Gr1 = (-)/(-) [absence of both]; Gr2 = (-)/(+) [proliferative]; Gr3 = (+)/(-) [cytopenic]; Gr4 = (+)/(+) [cytopenic and proliferative]) and evaluated OS per JAK2 </≥ 50% and PMF vs PPV/PET-MF. We assessed the tolerance of RUX ≥3 years. We used descriptive statistics, Kaplan-Meier curve with log-rank test and regression analysis for demographics, estimation of OS and its comparison. OS was censored at the time of stem cell transplantation. Results: Median age of the entire cohort was 75 years (64% males). Patients with JAK2 <50%, more likely PMF, had more anemia and thrombocytopenia, higher blasts, less leukocytosis, and smaller splenomegaly. JAK2 </≥ 50% did not discriminate OS of the entire group, PMF or PPV/PET-MF (median OS of ~ 45 months for each; only PPV/PET-MF with 64 months). OS of Gr1-4 according to JAK2 </≥ 50% and PMF/ PPV/PET-MF and combined OS of patients with comparable outcome (A-D) are shown in the table. The final groups with distinct outcomes included: A+B) non-cytopenic PET/PPV-MF and PMF irrespectively of proliferation and JAK2% - with one exception of non-cytopenic, proliferative PMF with JAK2 ≥50% - had median OS of 70 months (range, 54-86); D) cytopenic and proliferative PMF with any JAK2% and PPV/PET-MF with JAK2 < 50% of median OS 19 months (range, 13-25), and C) the rest of the cytopenic patients and non-cytopenic, proliferative PMF with JAK2 ≥50% with a median OS of 36 months (range, 32-42). Among the 3 final groups, similar proportion of patients were exposed to RUX during their follow-up: 36% (A+B), 31% (B) and 28% (C), respectively (p =0.13). The most patients in (A+B) group were able to tolerate RUX for ≥3 years (p =0.036). All patients had improved OS with RUX (data to be presented). Conclusions: Cytopenias and/or proliferation, rather than JAK2 </≥50%, define the outcome of PMF and PPV/PET-MF patients. [Table: see text]

P506: ACHIEVEMENT OF MEASURABLE RESIDUAL DISEASE CLEARANCE IS A STRONGER PREDICTOR OF PATIENT OUTCOME THAN TREATMENT INTENSITY IN NEWLY DIAGNOSED PATIENTS WITH ACUTE MYELOID LEUKEMIA

Background: Modern therapy for acute myeloid leukemia (AML) can consist of either intensive or low-intensity regimens selected based on patient (pt) age/comorbidities. Measurable residual disease (MRD) has emerged as a strong independent prognostic factor in AML. It is unknown whether pts who achieve similar levels of MRD clearance experience comparable outcomes irrespective of treatment intensity. Aims: To establish the relative prognostic contribution of treatment intensity and MRD status on overall survival (OS) and relapse-free survival (RFS) in newly diagnosed AML pts who have achieved a first response. Methods: We conducted a retrospective chart review to identify non-CBF, non-APL AML pts treated at our institution between 2010 and 2021 with intensive (IA; int/high-dose cytarabine + anthracycline-based, without venetoclax) or low-intensity (Lo + VEN; low-dose cytarabine/hypomethylating agent-based, with venetoclax) regimens who had achieved CR/CRi/MLFS and undergone MRD testing by multiparameter flow cytometry at time of first response. Differences in baseline pt characteristics were evaluated using the Chi-square or Wilcoxon-Mann-Whitney tests for categorical and continuous variables, respectively. The Kaplan-Meier method was used to estimate median OS and RFS, with pts censored at the time of stem cell transplantation (SCT). Multivariate analysis was performed using a Cox proportional hazards model. Results: We identified 635 pts meeting inclusion criteria. Baseline characteristics are shown in Table 1. Compared to the IA-treated pts (n=385), pts treated with Lo + VEN (n=250) were significantly older, more likely to be male, less likely to achieve MRD clearance, and more likely to be classified as adverse risk by ELN 2017. The SCT rate in the Lo + VEN cohort was half that of the IA cohort (25% vs 50%). Median OS was 51m, 24.6m, 15m, and 9.9m in the IA MRD(-), Lo + VEN MRD(-), IA MRD(+), and Lo + VEN MRD(+) groups, respectively. Median RFS was 27.8m, 15.4m, 7.3m, and 5.2m in the IA MRD(-), Lo + VEN MRD(-), IA MRD(+), and Lo + VEN MRD(+) groups, respectively. Pts within the same MRD category (+ or -) had significantly higher OS and numerically higher RFS if treated with IA versus Lo + VEN. When the analysis was restricted to pts aged ≥ 60 years (n=56 in IA, n=239 in Lo + VEN; Fig. A-B), the differences within MRD categories did not reach statistical significance (median OS NR in IA MRD(-) vs 24.6m in Lo + VEN MRD(-), p=0.08; median OS 13m in IA MRD(+) vs 10.6m in Lo + VEN MRD(+), p=0.50; median RFS NR in IA MRD (-) vs 15.4m in Lo + VEN MRD(-), p=0.07; median RFS 25.1m in IA MRD(+) vs 5.3m in Lo + VEN MRD(+), p=0.24). The SCT rate was 29% (87/295) in the age ≥ 60 cohort. Given the confounding effect of unbalanced pt characteristics between the IA and Lo + VEN cohorts, we performed a multivariate analysis on the full population (n=635) taking into consideration the effects of age, treatment intensity, MRD status, and ELN category on OS and RFS (all significant by univariate analysis). In the multivariate analysis for OS, ELN adverse risk was the strongest predictor (HR 2.09, p<0.001), followed by MRD(+) status (HR 1.68, p<0.001), while treatment intensity and age were not significantly predictive. For RFS, ELN adverse risk (HR 2.31, p<0.001) and MRD(+) status (HR 1.98, p<0.001) were also the only two significant predictors. Image:Summary/Conclusion: In newly diagnosed AML patients, MRD status at time of first response and ELN risk are stronger predictors of pt outcome than intensity of therapy received.

Non-Infectious Morbidity during Pediatric Acute Myeloid Leukemia Chemotherapy in the Netherlands: A 15-Year Overview

IntroductionTogether with considerable improvement in diagnostics and supportive care measures, treatment intensification has contributed to the improvement of pediatric acute myeloid leukemia (AML) survival outcomes. However, treatment-related toxicity is a consequence of intensified chemotherapy regimens, which has profound implications for both morbidity and mortality. Despite the known devastating impact of all types of toxicity on quality of life (QoL), studies presenting the different forms of non-infectious toxicity prevalent during the most recent Dutch pediatric AML protocols are lacking given that only prior protocols have been evaluated in this manner as of yet. Furthermore, the literature on non-infectious toxicity incidence in pediatric AML patients is relatively scarce. Therefore, the objectives of this study were to: 1) evaluate the cumulative incidence (C.I.) of severe, but non-lethal, non-infectious toxicity during AML treatment according to the last three consecutive protocols of the Dutch Childhood Oncology Group (DCOG), and 2) compare treatment-related toxicity frequencies between protocols.MethodsA retrospective chart review was performed on 245 Dutch patients diagnosed with de novo AML (acute promyelocytic leukemia, myeloid leukemia of Down Syndrome, and secondary AML were excluded) and treated according to ANLL-97/AML-12 (1998-2005) n=118, AML-15 (2005-2010) n=60, or DB-AML-01 (2010-2013) n=67. Table 1 details protocol specifics, including drug dosages per course. Grade 3-4 toxicities, including hematological toxicity, cardiotoxicity, respiratory toxicity, mucositis, typhlitis, nephrotoxicity, hepatotoxicity, neurotoxicity, pain, allergic anaphylactic reaction, and elevation of alanineaminotransferase or bilirubin were defined according to Common Terminology Criteria for Adverse Event version 4.0, excluding infectious toxicity. Grade 5 toxicity (treatment-related mortality) was beyond the scope of this study. Intensive care unit (ICU) admission data was additionally assessed. Toxicity C.I.s were determined via competing events analyses. Relapse and death were considered competing events. Patients were censored at time of stem cell transplantation. Per-protocol comparisons were conducted via Chi-square test, due to lack of sufficient power required to calculate C.I.s.ResultsMedian age at diagnosis was 6.0 years [interquartile range (IQR) 1.0-12.0], 58% were male. Mucositis was the most frequent form of non-hematological toxicity with a C.I. of 86.1% (standard error (S.E.) 3.5%), followed by hepatotoxicity (C.I. 27.4%, S.E. 2.9%), and respiratory toxicity (C.I. 24.6%, S.E. 3.0%) (Table 2). Eighty-three patients (C.I. 33.9%, S.E. 3.0%) were admitted to the ICU at least once, for a median of 6.0 days [IQR 2.0-15.0] (Table 2).Relatively more blood transfusions (both erythrocyte and thrombocyte) were administered to patients treated according to AML-15 (98.3%) and DB-AML-01 (97.0%) compared to AML-12 (86.4%) (p=0.01 and p=0.02, respectively). Relatively more patients suffered from severe mucositis during DB-AML-01 compared to AML-12 (43.4% vs. 25.4%, p=0.01). More patients treated according to AML-15 had bilirubin levels >3x upper limit of normal (ULN) compared to those treated according to AML-12 (13.3% vs. 3.4%, p=0.01). There were no differences in non-infectious toxicity frequency between AML-15 and DB-AML-01. Other forms of toxicity did not differ significantly between protocols. The percentage of patients admitted to the ICU at least once during treatment was 33.9% in AML-12, 26.7% in AML-15, and 40.3% in DB-AML-01.ConclusionsThe high incidence of severe short- and long-term toxicities during pediatric AML therapy poses substantial challenges for patients, families, and care providers. Mucositis was the most common form of non-hematological, non-infectious toxicity in the whole cohort and across all Dutch protocols. Toxicities were more prevalent during the more recent protocols (AML-15 and DB-AML-01) compared to AML-12. Therefore, our findings are important in that they substantiate the need to optimize pediatric AML care in a manner which decreases treatment-related toxicity and QoL impairment. High treatment-related morbidity rates stress the urge to improve supportive care and develop less toxic treatment, while maintaining efficacy. [Display omitted] DisclosuresZwaan: Sanofi: Consultancy.

Quantifying the Effects of Hip Surgery on the Sphericity of the Femoral Head in Patients with Mucopolysaccharidosis Type I.

The introduction of stem cell transplantation has improved life expectancy and cognitive outcome in patients with mucopolysaccharidosis I, but this condition remains associated with substantial residual disease in several parts of the body. Many patients have hip dysplasia with progressive medial flattening of the femoral head. Quantitative evidence on the effect of surgery on remodeling to sphericity of flattened femoral heads is lacking. In the present study, we used statistical shape modeling to quantify the effect of hip surgery on the sphericity of the femoral head in patients with mucopolysaccharidosis I. We performed a retrospective case control study involving a series of 23 patients with hip dysplasia due to mucopolysaccharidosis I. Surgery was not offered to the first 11 children (control group). Following a change in treatment protocol, the next 12 children underwent bilateral proximal femoral varus derotation osteotomy and Pemberton osteotomy for the treatment of acetabular dysplasia with progressive femoral head flattening (surgery group). The surgery and control groups were compared with a reference group of patients with normal hips. Statistical shape modeling was used to quantify the shape of the femoral head (i.e., flattening and/or roundness of the epiphysis). The mean age at the time of stem cell transplantation in the surgery and control groups was comparable (1.2 years). The mean age at the time of surgical intervention was 5.5 years, and mean duration of postoperative follow-up was 3.3 years. Statistical shape modeling showed variations within the total group in terms of medial indentation, width, height, and sphericity of the femoral heads. In contrast to the progressive femoral head flattening in the control group, the surgery group showed improvement of the sphericity of the femoral head after surgery. The overall shape characteristics of the femoral head in the surgery group were similar to those of the reference group of patients with normal hips. To our knowledge, this is the first study in patients with mucopolysaccharidosis I that has shown quantitative remodeling of the dysplastic, flattened femoral head to normal sphericity after increasing containment of the femoral head. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Clinical Course, Outcomes and Genetic Characterization of Patients with Isolated Myeloid Sarcoma

Clinical Course, Outcomes and Genetic Characterization of Patients with Isolated Myeloid Sarcoma

The Value of Predictive Nursing in Perioperative Period of Allogeneic Hematopoietic Stem Cell Transplantation

Background: Predictive nursing is a new concept proposed in recent years. Studies have shown that predictive care is effective in critically ill and surgical patients. However, the application and research of predictive nursing in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT) during perioperative period is still lacking. Objective: The value and clinical effect of predictive nursing in allo-HSCT during the perioperative period. Methods: Retrospective analysis was performed on 36 patients with hematological disease who had received allo-HSCT. Observation group A was the patient who received oral care, perineal care and perianal care during the transplantation period; group B was the patient who received only one of the three care items; group C was the patient who received no nursing intervention. And then the time of stem cell transplantation, the incidence of infection, and the cost of treatment were analyzed among the three groups. Results: Predictive nursing intervention can significantly shorten the transplantation time of granulocytes and megakaryocytes (A vs. C, <i>P</i>=0.000, <i>P</i>=0.000; B vs. C, <i>P</i>=0.000, <i>P</i>=0.000). Patients receiving oral care, perineal care and perianal care at the same time had a tendency to shorten the transplant time of stem cells and effectively reduce the incidence of respiratory and urinary tract infections compared with patients receiving only one nursing intervention (X²=5.538, X²=5.924; <i>P</i>=0.019, <i>P</i>=0.05). And reduce the cost of treatment during transplantation (A vs. C, <i>P</i>=0.006). Conclusions: In the perioperative period of allogeneic hematopoietic stem cells, various predictive nursing interventions can shorten the transplantation time of stem cells, reduce the incidence of infection, and thus reduce the economic burden of patients. It is a cheap and effective method and worthy of clinical application.

Busulfan, Melphalan, and Bortezomib Compared to Single Agent High-Dose Melphalan As a Conditioning Regimen for Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma: Long Term Follow up of a Novel Conditioning Regimen

Introduction: Multiple myeloma (MM) remains incurable when treated with novel myeloma therapies in combination with high dose chemotherapy and autologous stem cell transplantation (ASCT). In contrast to the accelerated development of effective new drugs for induction, maintenance, and relapse, single-agent melphalan remains the standard for conditioning before ASCT. Is this phase II trial, we prospectively evaluated a conditioning regimen consisting of high-dose intravenous busulfan and melphalan followed by bortezomib (BUMELVEL), an agent shown to be potentially synergistic in combination with alkylating agents. We report our 7 year long term follow up with direct comparison to a contemporaneous CIBMTR cohort with the primary aim of both long term progression-free (PFS) and overall survival (OS). Methods: This phase I/II study was conducted between July 2009 and May 2012 at Loyola University Medical Center. MM patients with any disease response following induction were enrolled at time of stem cell transplantation. 43 patients received BUMELVEL conditioning followed by ASCT on the phase II portion of this study. Busfulan was administered intravenously (i.v.) daily for 4 days with the first 2 days (days −6 and −5) at fixed dose of 130 mg/m2 over 3 hours and the subsequent 2 doses (days −4 and −3) adjusted to achieve a target AUC total of 20,000 μM·min determined by pharmacokinetic (PK) analysis. Melphalan at 140 mg/m2 and bortezomib at 1.6 mg/m2 were administered i.v. on days −2 and −1, respectively. Maintenance therapy was not planned. Patients received prophylaxis for oral mucositis with palifermin. Data from this phase II clinical trial were compared against a matched control cohort of contemporaneous North American MM patients from the CIBMTR database (n = 162) receiving conditioning with single agent iv melphalan at a dose of 200mg/m2. The primary objectives of this study were median PFS and toxicities. Results: Baseline patient characteristics are described in Table 1. More patients in the BUMELVEL arm received greater than one line of therapy prior to transplant (53 v 33%). There were more standard risk patients per Mayo Stratification (Kumar et al, Mayo Clin Proc 2009) in the MEL200 group (78%) v the BUMELVEL group (40%). There was no difference in response rates at day 100 (p=0.48) but a trend toward improved response at 1 year in the BUMELVEL arm with 77% achieving a VGPR or better versus 60% in the MEL200 group (p-0.09). No patients in the BUMELVEL group received planned maintenance therapy post-transplant whereas 112 (69.6%) in the MEL200 control arm received planned post-transplant maintenance. Non-relapse mortality was 2% (range 0-9%) in the BUMELVEL group and 10 (6%, range 3-11) in the MEL200 but this was not statistically significant in both univariate and multivariate modeling (p=0.25). There were no episodes of sinusoidal obstructive syndrome in the BUMELVEL group and 37% of patients experienced grade 3 mucositis with no grade 4 mucositis. After a median of more than seven years of follow up, the five year PFS was 47% (95% CI; 32-62) in the BUMELVEL group versus 30% (95% CI; 23-37) in the MEL200 group (p=0.05) (Figure 1). Notably the 7-year PFS in the BUMELVEL group was 32% (range 18-48). In multivariate analysis for PFS, BUMELVEL conditioning (HR 0.65; 95% CI 0.44-0.97)(p=0.036), time from diagnosis to transplant of greater than versus less than 12 months (HR 1.64; 95% CI 1.18 - 2.27), and disease status at transplant CR versus other (p=0.006) were all predictive of PFS (table 2). OS was not different between the two groups with a 7 year survival of 64% (95% CI; 48-79) in the BUMELVEL group versus 55% (95% CI; 46-64%) in the MEL200 group (Figure 1) which was confirmed on multivariate analysis (p=0.33). Discussion: Similar to recent reports in the literature comparing busulfan and melphalan to melphalan alone (Bashir et al, Lancet Hem 2019), we show that although depth of response was similar between the BUMELVEL group and the historical MEL200 comparator, the BUMELVEL group experienced an improved PFS. Importantly, we report no cases of SOS and a low non-relapse mortality of only 2% (v 6% in the historical control) reinforcing that the preparatory regimen in myeloma can be intensified safely with improved duration of unmaintained PFS. These long term results confirm a sustained benefit of novel combination conditioning in MM and the need for novel transplant preparative regimens. Disclosures D'Souza: EDO-Mundapharma, Merck, Prothena, Sanofi, TeneoBio: Research Funding; Prothena: Consultancy; Pfizer, Imbrium, Akcea: Membership on an entity's Board of Directors or advisory committees. Hari:Celgene: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Research Funding; Janssen: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Amgen: Research Funding; Spectrum: Consultancy, Research Funding; Sanofi: Honoraria, Research Funding; Cell Vault: Equity Ownership; AbbVie: Consultancy, Honoraria. Stiff:Unum: Research Funding; Gamida-Cell: Research Funding; Incyte: Research Funding; Cellectar: Research Funding; Amgen: Research Funding; Gilead/Kite Pharma: Consultancy, Honoraria, Research Funding.

Clonal hematopoiesis of indeterminate potential and its impact on patient trajectories after stem cell transplantation.

Clonal hematopoiesis of indeterminate potential (CHIP) is a recently identified process where older patients accumulate distinct subclones defined by recurring somatic mutations in hematopoietic stem cells. CHIP’s implications for stem cell transplantation have been harder to identify due to the high degree of mutational heterogeneity that is present within the genetically distinct subclones. In order to gain a better understanding of CHIP and the impact of clonal dynamics on transplantation outcomes, we created a mathematical model of clonal competition dynamics. Our analyses highlight the importance of understanding competition intensity between healthy and mutant clones. Importantly, we highlight the risk that CHIP poses in leading to dominance of precancerous mutant clones and the risk of donor derived leukemia. Furthermore, we estimate the degree of competition intensity and bone marrow niche decline in mice during aging by using our modeling framework. Together, our work highlights the importance of better characterizing the ecological and clonal composition in hematopoietic donor populations at the time of stem cell transplantation.

The Gut Microbiome &amp; Cancer Immunotherapy

The Gut Microbiome &amp; Cancer Immunotherapy

The appropriate time for stem cell transplantation in albino rat with amiodarone induced lung fibrosis: histological and immunohistochemical study

Background: The fibrosing form of lung injury had bad progressive course and lethal outcome.Aim of the work: This study throws light on the possible protective and/or therapeutic consequence of mesenchymal stem cell therapy in lung fibrosis induced by amiodarone in albino rat. In addition to study the possible recovery of damaged lung after amiodarone withdrawal. Material & Methods: Forty five adult male albino rats were divided into five equal groups. Group I (control); group II (amiodarone) received amiodarone 30 mg/kg orally for 6 days /week for 6 weeks, group III (withdrawal); group IV (early stem cell) mesenchymal stem cell was administrated after 1st dose of amiodarone therapy ; group VI (late stem cell) mesenchymal stem cell was administrated immediately after amiodarone suspension . Lung samples were processed and examined using histological and immunohistochemical techniques and the obtained data was subjected to statistical analysis.Results: Amiodarone treated group displayed obstructed bronchioles, collapsed alveoli, inflammatory cell infiltration ,thickened interalveolar septa and pulmonary vessels wall. Increased collagen fibers deposition between alveoli and around blood vessels in addition to highly expressed caspase-3. Group III (withdrawal) recorded only mild improvement. Group IV (early stem cell therapy ) showed advanced improvement of pulmonary alveolar architecture, on other side group V (late stem cell therapy)revealed moderate improvement of lung injury.Conclusion: The majority of amiodarone lung toxicity manifestations and lung fibrosis were regressed by bone marrow derived mesenchymal stem cell (BMSCs) therapy and the best result obtained when stem cell initiated early in the development of pathogenesis.

Minimal Residual Disease (MRD) Analysis Using Multiparametric Flow Cytometry (MFC) and Identification of Differences in Subpopulations Using Next Generation Sequencing (NGS) in the Bone Marrow (BM) of Multiple Myeloma (MM) Patients (pts)

Introduction: MM is characterized by the accumulation of aberrant BM plasma cells (aPCs). The use of novel agents for anti-MM treatment has enabled the achievement of deeper responses and prolonged progression free survival (PFS) and overall survival (OS). These advances have created the need for sensitive means to detect residual PCs. MFC allows aPC detection with high sensitivity and is used with NGS in clinical trials (CTs) (Paiva, 2015-2018). It allows the detection of residual cells after anti-MM therapies and is a risk denominator of pt subgroups and post-therapeutic outcome. The incorporation of cost-effective, readily available and standardized MRD tools into CTs and clinical practice seems a key requisite. It may allow the improvement of clinical decisions: 1) timing of stem cell transplantation (SCT), 2) need for consolidation, 3) duration of maintenance, 4) therapy modulations and 5) early relapse detection. Since MRD gains importance for novel agents' potency to achieve MRD negativity, including FDA/EMA-approvals, we assessed MFC for detection of aPCs, their change to treatment and over time.Methods: We systematically validated a 6-, 8- and 10-color panel using CD38, CD138, CD19, CD45, CD27, CD56, CD28, CD81, CD117, CD200 and kappa/lambda (k/l) in 9 different MM cell lines (MMCLs) and 213 BM, PB, leukapheresis (LA), extramedullary (EM) samples of 122 different MM pts and 14 healthy individuals (HI). These were immediately analyzed after sampling, using a bulk-lysis protocol. To reach a high sensitivity, >3x106 viable nucleated cells were analyzed. MFC validation included fluorescence-minus-one-(FMO), isotype- and spike-in-controls to evaluate the reliability and sensitivity of our panels. Spike-in controls were performed using a dilution assay to recover defined MMCL cells in the PB of HI. Data analysis was accomplished using the BeckmanCoulter software Kaluza®. We compared MFC using BM and PB samples of HI, MM pts at initial diagnosis (ID) or with progression (PD), after standard therapy (ST) and SCT. Additionally, BM samples at ID were sorted into each 4 aPC- and normal PC- (nPC) subpopulations for DNA and RNA sequencing and follow-up. The study was performed with written consent of all pts and HIs and approval of the ethics committee.Results: The antigen expression levels in 9 MMCLs using our 6-, 8- and 10-color panel could be confirmed as reported. The expression levels of antigens included in all panels were similar in all MMCLs (RPMI 8226; U266; IM-9; MM1.S; MM1.R; L363; Karpas620; NCI-H929; OPM-2). For all panels, we established easy to adapt gating strategies, using commercially available software to identify aPCs vs. nPCs in all analyzed samples. Using the 6-color panel, differentiation into up to 4 phenotypic subpopulations of aPCs and nPCs in MM pts and up to 4 subpopulations of nPCs in HI was achieved, depending on the heterogeneous phenotype the individual was expressing. Moreover, both DNA and RNA of obtained subpopulations were collected and analyzed via sequencing. Since in 1% of our samples, aPCs remained undetected via 6-color panel using surface antigens exclusively, we added k/l and did detect aPCs in all pts. The 10-color panel identified aPC- and nPC-subpopulations in even more detail. We determined a MRD sensitivity of 10-5, confirmed via independent dilution assays. In 48% of BM and PB samples, aPCs were determined at ID and PD; 52% were assessed for MRD after ST and SCT. Of the latter, 55% were BM samples, of which 5% showed MRD negativity of <0.001%. The median time from ST- or SCT-treatment to 1rst MRD evaluation was 44 days; this being assessed at subsequent time points currently. These data will be shown at the meeting.Conclusion: Our 6-, 8-, and 10-color panels allow highly sensitive detection of aPCs vs. nPCs in MM samples. These panels have been validated using various controls, dilution assays, 9 MMCLs, MM pt samples and HI and can be implemented into routine diagnostics. The analysis of DNA and RNA expression patterns in distinct subpopulations will generate relevant insight, which subclones contribute to response vs. resistance mechanisms. The EuroFlow Consortium have established a two 8-color tubes test for identification of aPCs, which - albeit used worldwide - may not be applicable for every center and every pt outside CTs. Therefore, meticulously validated alternatives as shown here are of interest. Our 8-color panel has been included into our CT portfolio. DisclosuresAzab:Cellatrix LLC: Equity Ownership, Other: Founder and owner; Targeted Therapeutics LLC: Equity Ownership, Other: Founder and owner; Ach Oncology: Research Funding; Glycomimetics: Research Funding. Zeiser:Jazz Pharmaceuticals: Research Funding. Wäsch:Pfizer: Honoraria.

Stem cell transplantation for T-cell lymphomas in Taiwan.

T-cell lymphomas are generally aggressive malignancies with poor prognosis. There are no standard treatment guidelines for T-cell lymphomas, and the timing of stem cell transplantation (SCT) is not well known. In this study, we investigated the outcomes of Taiwanese patients with T-cell lymphomas after SCT. We retrospectively analyzed 131 patients with T-cell lymphomas receiving SCT (autologous: 90, allogeneic: 41) from 2009 to 2014. More autologous SCT recipients were ALCL or in complete remission, and more allogeneic recipients had advanced disease. 56 patients who were sensitive to chemotherapy underwent SCT as upfront setting. The 2-year PFS and OS rates were 67.0 and 64.5%, respectively. Regarding disease status before transplantation, patients with CR1 had the best outcomes. Among different subtypes, patients with natural killer/T-cell lymphomas showed the worst outcomes, with 2-year OS rate of 23.5%. The OS rates for the other three major subtypes were as follows: 72.9% for ALCL; 75.0% for AITL; and 51.4% for PTCL-NOS. For more rare subtypes, such as ATLL and SPTCL, data from our study show that SCT can be beneficial. We concluded that upfront autologous SCT is feasible and effective for patients with low PIT, and disease status at transplant is the strong predictor of outcome.

Therapeutic plasma exchange in primary hemophagocytic lymphohistiocytosis: Reports of two cases and a review of the literature

We report two children who were diagnosed as having primary hemophagocytic syndrome and who successfully underwent therapeutic plasma exchange (TPE). The first patient was a 6-month-old girl diagnosed with HLH who was admitted to the pediatric intensive care unit. The patient's clinical condition worsened on the 9th day of the HLH-2004 treatment protocol. Her ferritin level was found 50.000 ng/mL, and TPE was performed for 9 sessions, after which her clinical condition and laboratory findings improved. The patient is still on the HLH-2004 protocol and waits for a suitable stem cell transplantation donor. Case 2 involved a Syrian girl with HLH under follow-up who was receiving the HLH-2004 treatment protocol for reactivation. She presented to emergency department with fever, where her ferritin level was measured greater than 100.000 ng/mL; she was then transferred to the pediatric intensive care unit where four sessions of TPE were performed, after which her clinical condition and laboratory findings improved. However, the patient was admitted again one month later with gastrointestinal bleeding and died despite all efforts.By describing these two cases, we wish to emphasize that TPE can produce a rapid improvement until the time of stem cell transplantation in patients with hemophagocytic syndrome who do not respond to traditional treatments.

The fludarabine, cytarabine, and granulocyte colony-stimulating factor (FLAG) chemotherapy regimen is an alternative to anthracycline-based therapy for the treatment of acute myeloid leukemia for patients with pre-existing cardiac disease.

We conducted a retrospective study assessing FLAG (fludarabine, cytarabine, and granulocyte colony-stimulating factor) as first-line treatment in 56 newly diagnosed acute myeloid leukemia patients considered ineligible for anthracycline-based treatment due to advanced age, significant comorbidities, or pre-existing cardiac disease. The median age was 69 (21-80); 46% received FLAG for pre-existing cardiac disease and others due to age (32%), non-cardiac comorbidities (20%), or previous anthracycline exposure (2%). The induction mortality was 16% and, among evaluable patients, 48% achieved a complete remission after the first induction course with an additional patient achieving a remission after a second course for a total complete remission rate of 50%. Four patients proceeded to an allogeneic stem cell transplant including two with pre-existing cardiac disease. Among non-transplanted patients, the relapse rate (RR) was 47%. When censored at time of stem cell transplant, the median relapse-free survival was 14.7 months. The median overall survival was 9.3 months with 1- and 2-yr survivals of 44% and 22%, respectively. There was no difference in clinical outcomes between patients treated with FLAG for cardiac reasons vs. other reasons. In conclusion, FLAG is a useful alternative to anthracycline-based induction for Acute myeloid leukemia in those with significant comorbidities including pre-existing cardiac disease.

Timing of Stem Cell Transplantation and Outcomes in Light Chain Amyloidosis

Timing of Stem Cell Transplantation and Outcomes in Light Chain Amyloidosis

Liver Tropism and Factor VIII Transgene Expression after Intrauterine Chorionic Villus Stem Cell Transplantation

INTRODUCTION: Gestation is characterized by rapid mitosis and histogenesis in an immune naïve environment. Growth and development of vital organs are occurring continuously at different time points throughout pregnancy under the regulation of paracrine signals, transcription and growth factors. Appropriate timing to target the developing organ of interest during in utero stem cell transplantation (IUT) may result in high level engraftment in that organ as well as recognition of foreign cells as self. Hemophilia A, is an X-linked recessive bleeding disorder caused by a mutation of the gene that encodes Factor VIII (FVIII) which is primarily produced by the liver. We hypothesize that introduction of stem cells in utero during hepatogenesis in mice (e9.5-15 days) will result in localization and persistence of stem cells in the liver.METHODOLOGY: We reported isolation and characterization of early preterm chorionic villus derived mesenchymal stem cells (PMSCs) at GA 9-13 weeks. PMSCs (n =5) were transduced with a lentiviral vector encoding B-domain deleted FVIII, GFP and luciferase reporter genes (pCCLc-MNDU3-eGFP/LUC-PGK-F8-WPRE) at an MOI (Multiplicity of Infection) of 3. Chromogenic assay was performed on cell supernatant of transduced PMSCs 72 hours after transduction. Prior to transplantation, PMSCs were plated at different densities ranging from 250,000 cells to 2 x10^6 cells and subjected to bioluminescence imaging. Intraperitoneal transplantation of PBS (control group) or with 1 x10^6 PMSCs (experimental group) was conducted in fetal mice at e12-14 days using a 33 gauge non-coring needle. Bioluminescence analysis was performed 24 hours after IUT on dams, and 12-15 days after transplantation. Mice were euthanized and liver tissue was harvested from all animals. Expression of FVIII was analyzed by RT-PCR from both groups.RESULTS: Bioluminescence imaging revealed focal density and transgene expression for transduced cells in vitro, in vivo at 24 hours and in postnatal pups 12-14 days after transplantation. Postmortem bioluminescence analysis of IUT transplanted mice showed positive bioluminescence in the livers of pups injected with transduced PMSCs. RT-PCR analysis of the liver samples using human specific FVIII primers revealed FVIII expression in liver tissues in PMSC treated mice while negative for PBS treated mice.CONCLUSION: These results demonstrate the functional survival and localization of genetically modified PMSCs in the liver after intrauterine transplantation for up to two weeks. This study provide better understanding of the cell fate of stem cells after IUT and suggest that appropriate timing of stem cell transplantation in utero may lead to immunological tolerance. DisclosuresPowell:CSL Behring: Employment.

The Prognostic Significance of TP53 Mutations for Overall Outcome in Lower-Risk MDS Patients

BACKGROUND AND AIMSRecent results have indicated that the TP53 mutations had a negative prognostic relevance for lower-risk myelodysplastic syndrome (MDS) patients but the relations between the presence of mutations and treatment has not been clarified yet. Therefore, we analyzed the prevalence of TP53 mutations in lower-risk MDS patients and determined the proportion of TP53 mutated bone marrow cells during the disease. We further observed mutual relation of treatment and mutated clones and defined impact of mutations on survival of patients.METHODSTP53 mutations were analyzed in DNA from bone marrow of 141 low risk or intermediate-1 risk MDS patients included into the cohort according to the International Prognostic Scoring System using primers designed within the IRON-II study research consortium (Roche Applied Science) on the GS Junior system. If mutations were detected, we searched for mutations at different timepoints of the disease and overall 210 samples were examined for mutations. Ten of the 16 patients with TP53 mutation received lenalidomide and/or 5-azacytidine. Mean coverage of sequenced exons was about 800-fold allowing an approximate detection sensitivity of 2% mutational burden.RESULTSThe overall incidence of TP53 mutations was 11.3 % (16/141), three patients harbored two mutated clones. The mutation frequency in patients with and without del(5q) was 21% (13/62) and 3.8% (3/79), respectively. During the observation period, 37 patients (26.2%) died, the data obtained from remaining patients were censored either at the last date they were known to be alive (94 patients - 66.7%) or at the time of stem cell transplantation (HSCT) (10 patients - 7.1%). The median overall survival was 164.2 months in TP53 unmutated group and 84.5 in mutated group respectively calculated by Kaplan-Meier Survival Curves and the Log-Rank Test (P=0.18). Mutations were detectable in eight of the sixteen available patients (50%) at the time of diagnosis and remaining patients (50 %) displayed mutations in an average 35.1 months (range 12-69 months) from diagnosis.Three patients with mutational burden below 5% are alive more than 3 years without signs of disease progression and three patients with clone size above 40% died. The mutated clone disappeared after bone marrow transplantation in one patient. The proportion of TP53 mutated cells decreased radically after successful treatment with azacytidine in two patients. The clone size increased in four patients treated with lenalidomide and all of them died. Two patients with mutated clone sizes below 20% are still under observation.CONCLUSIONSWe confirmed the higher frequency of TP53 mutations in lower- risk MDS with del(5q) in a large cohort of patients. Patients with the TP53 mutations had shorter survival compared to those without mutation. The mutations were detected in a half of the patients at the time of diagnosis and approximately three years after diagnosis in remaining patients. The presence of TP53 mutation as an adverse prognostic factor should be routinely investigated in lower risk MDS patients at the time of the diagnosis as well as repeatedly in the course of the disease.Supported by grant (NT/13899, NT/14377, NT/14539) and the project for conceptual development of research organization (00023736) from the Ministry of Health of the Czech Republic. DisclosuresNo relevant conflicts of interest to declare.

Splenic Irradiation and a Reduced-Intensity Conditioning Regimen Prior to Allogeneic Stem-Cell Transplantation for Myelofibrosis

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative option for patients with myelofibrosis (MF). Reduced-intensity conditioning (RIC) regimens have been used to extend this therapy to older and sicker patients. Splenectomy prior to HSCT for MF has been shown to enhance neutrophil engraftment and decrease transfusion requirements, but has a reported operative mortality of 9% or higher. Splenic irradiation (sXRT) has been historically used as a palliative treatment in MF. We present our experience with a RIC regimen incorporating extracorporeal photopheresis (ECP) in combination with either pre-HSCT splenectomy or sXRT.Methods: The Tufts BMT database, the Center for International Bone Marrow Transplantation Registry (CIBMTR) database, and chart review were used to gather data. All patients underwent conditioning consisting of ECP administered on days -6 and -5, pentostatin 4mg/m2by continuous infusion over 48 hours on days -4 and -3, and a total dose of 600 cGy total body irradiation (TBI) administered in 3 fractions on days -2 and -1 (PPT). sXRT, when employed, was given in the week prior to start of PPT (days -6 to -11) with total doses ranging from 300 to 500cGy. Cyclosporine and methotrexate were used for GVHD prophylaxis. Patients surviving a minimum of six months were considered evaluable for response assessment. Complete hematologic response was defined as resolution of clinical signs of MF as well as normalization of peripheral blood counts (Hgb>10gm/dL, ANC>1000/µL, Platelets >100K and all counts below upper limit of normal) and the absence circulating blasts. Histological response could not be assessed due to lack of follow-up bone marrow data. Clinical improvement, stable disease, progressive disease, spleen response were defined using revised IWG-MRT guidelines. Overall survival (OS) was estimated using the Kaplan Meier method from time of stem cell transplant to death. Non-relapse mortality (NRM) was estimated from time of transplant to death, treating death due to MF and relapse as competing risks.Results: Ten patients (7 females, 3 males) with MF underwent allogeneic HSCT with PPT conditioning between February 2001 and December 2012. Median age was 54 years (40-60 years). Median time from diagnosis to transplant was 48 months (6-137 months). MF was primary in 8 and secondary to essential thrombocytosis in 2 patients. According to DIPSS scoring, 1, 2, 5 and 2 patients were low, intermediate-1, intermediate-2 and high risk respectively. Donors were equally distributed between matched related and matched unrelated. Bone marrow was used as the source in all but one patient. Nine patients (90%) had palpable splenomegaly. Six underwent splenectomy of which 1 died of a related complication (sepsis from abscess in the splenic bed). Three received sXRT prior to HSCT with no associated complications. All but one patient (who had a prior splenectomy) engrafted successfully. Median time to engraftment was 18 days (sXRT 18 days, splenectomy 19 days) for neutrophils and 26 days for platelets regardless of splenic therapy. Only 2 patients developed acute grade III-IV GVHD and 1 patient developed extensive chronic GVHD. 4/7 patients with a prior splenectomy were evaluable for disease response. Of these 2 had complete hematologic response, 1 had clinical improvement with eventual relapse, and 1 had progressive disease. Among the 3 patients receiving sXRT, 2 patients had complete hematologic response as well as a spleen response and 1 had stable disease.Three patients were alive at last follow-up. Causes of death included disease relapse (n=2), GVHD (=3) and sepsis (n=2). Cumulative incidence of NRM was 40% at 1 year. Five year OS was estimated at 30%.Discussion: Our data demonstrates that splenic XRT is well tolerated and equivalent to splenectomy in terms of engraftment outcomes and disease response. Survival and GVHD outcomes with PPT conditioning were similar to those reported with other RIC regimens. PPT is a reasonable conditioning regimen for these patients. Further study to optimize timing of HSCT and patient selection to reduce NRM is needed. DisclosuresComenzo:Millennium Pharmaceuticals: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Teva: Research Funding; Prothena: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Injection of Vessel-Derived Stem Cells Prevents Dilated Cardiomyopathy and Promotes Angiogenesis and Endogenous Cardiac Stem Cell Proliferation in mdx/utrn−/− but Not Aged mdx Mouse Models for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy. DMD patients lack dystrophin protein and develop skeletal muscle pathology and dilated cardiomyopathy (DCM). Approximately 20% succumb to cardiac involvement. We hypothesized that mesoangioblast stem cells (aorta-derived mesoangioblasts [ADMs]) would restore dystrophin and alleviate or prevent DCM in animal models of DMD. ADMs can be induced to express cardiac markers, including Nkx2.5, cardiac tropomyosin, cardiac troponin I, and α-actinin, and adopt cardiomyocyte morphology. Transplantation of ADMs into the heart of mdx/utrn(-/-) mice prior to development of DCM prevented onset of cardiomyopathy, as measured by echocardiography, and resulted in significantly higher CD31 expression, consistent with new vessel formation. Dystrophin-positive cardiomyocytes and increased proliferation of endogenous Nestin(+) cardiac stem cells were detected in ADM-injected heart. Nestin(+) striated cells were also detected in four of five mdx/utrn(-/-) hearts injected with ADMs. In contrast, when ADMs were injected into the heart of aged mdx mice with advanced fibrosis, no functional improvement was detected by echocardiography. Instead, ADMs exacerbated some features of DCM. No dystrophin protein, increase in CD31 expression, or increase in Nestin(+) cell proliferation was detected following ADM injection in aged mdx heart. Dystrophin was observed following transplantation of ADMs into the hearts of young mdx mice, however, suggesting that pathology in aged mdx heart may alter the fate of donor stem cells. In summary, ADMs delay or prevent development of DCM in dystrophin-deficient heart, but timing of stem cell transplantation may be critical for achieving benefit with cell therapy in DMD cardiac muscle.